Cabin

Abstract

The present invention suppresses increases in man-hours and cost.　This cabin (1) is provided with a front panel (31) disposed in front of a driver seat (6), a left door (27L) disposed to the left of the driver seat (6), a right door (27R) disposed to the right of the driver seat (6), a left front pillar (13L) disposed between the front panel (31) and the left door (27L), and a right front pillar (13R) disposed between the front panel (31) and the right door (27R), wherein, for the left front pillar (13L) and the right front pillar (13R), used are long materials that have the same shape and that are curved so as to bulge forward.

Description

cabin

[0001] The present invention relates to a cabin mounted on the body of a work machine such as a tractor, a wheel loader, or a backhoe.

[0002] A cabin disclosed in Patent Document 1 is known.

[0003] The cabin disclosed in Patent Document 1 includes two front pillars spaced apart in the width direction of the cabin. The two front pillars are a first left front pillar and a second right front pillar. The first front pillar and the second front pillar are arranged side by side. The cabin also includes a first left rear pillar and a second right rear pillar. The first left rear pillar is located rearward of the first front pillar, and the second right rear pillar is located rearward of the second front pillar. The first rear pillar and the second rear pillar are spaced apart in the width direction. Furthermore, the upper portions of the first front pillar and the second front pillar are connected in the width direction by a front upper frame (front beam), and the upper portions of the first rear pillar and the second rear pillar are connected in the width direction by a rear upper frame (rear beam). The upper portions of the first front pillar and the first rear pillar are connected to each other by a first side upper beam (left side beam) extending in the longitudinal direction, and the upper portions of the second front pillar and the second rear pillar are connected to each other by a second side upper beam (right side beam) extending in the longitudinal direction. In other words, the cabin of Patent Document 1 is configured by combining eight long frame members: the first front pillar, the second front pillar, the first rear pillar, the second rear pillar, the front upper frame, the rear upper frame, the first side upper beam, and the second side upper beam.

[0004] Japanese Patent Publication No. 2020-097368

[0005] In conventional cabins, the eight frame members that make up the cabin each have a different shape, are bent in different directions, and have no commonality in shape. Therefore, each frame member had to be manufactured separately, and molds and other tools had to be prepared separately for manufacturing. Furthermore, the number of processing steps required was equal to the number of frame members. In other words, conventional cabins had the problem of increased labor and costs involved in manufacturing the cabin.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a cabin that can suppress increases in labor and costs by using the same frame material for the left and right sides.

[0007] The technical means of the present invention for solving the above-mentioned technical problems is characterized by the following points.

[0008] A cabin according to one aspect of the present invention comprises a front panel disposed in front of the driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left front pillar disposed between the front panel and the left door, and a right front pillar disposed between the front panel and the right door, and the left front pillar and the right front pillar are made of elongated material of the same shape that curves to bulge forward.

[0009] The left front pillar and the right front pillar may be made of a frame material in which the longitudinal ends of the elongated material are cut off and the portions other than the longitudinal ends have the same shape.

[0010] A cabin according to one embodiment of the present invention comprises a front panel arranged in front of the driver's seat, a left door arranged to the left of the driver's seat, a right door arranged to the right of the driver's seat, a left front pillar arranged between the front panel and the left door, and a right front pillar arranged between the front panel and the right door, wherein the left front pillar and the right front pillar are made of long material that curves so as to bulge forward over the entire area from the top to the bottom, and whose upper and lower halves have symmetrical curvatures with a dividing line halfway up and down.

[0011] A cabin according to one embodiment of the present invention comprises a rear panel disposed behind the driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left rear pillar disposed between the rear panel and the left door, and a right rear pillar disposed between the rear panel and the right door, and the left rear pillar and the right rear pillar are made of elongated material of the same shape that curves to bulge toward the rear.

[0012] The left rear pillar and the right rear pillar may be formed from a frame material in which the longitudinal ends of the elongated material are cut off and the portions other than the longitudinal ends have the same shape.

[0013] A cabin according to one embodiment of the present invention comprises a rear panel disposed behind the driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left rear pillar disposed between the rear panel and the left door, and a right rear pillar disposed between the rear panel and the right door, wherein the left rear pillar and the right rear pillar are made of long material that curves so as to bulge rearward over the entire area from the top to the bottom, and whose upper and lower halves have symmetrical curvatures with a dividing line halfway up and down.

[0014] A cabin according to one embodiment of the present invention comprises a left door located to the left of the driver's seat, a right door located to the right of the driver's seat, a left side beam provided at the upper end of the left door, and a right side beam provided at the upper end of the right door, wherein the left side beam and the right side beam are made of elongated material of the same shape that curves upward over the entire area from the front end to the rear end.

[0015] The left side beam and the right side beam may be made of a frame material in which the longitudinal ends of the elongated material are cut off and the portions other than the longitudinal ends have the same shape.

[0016] A cabin according to one embodiment of the present invention comprises a left door located to the left of the driver's seat, a right door located to the right of the driver's seat, a left side beam provided at the upper end of the left door, and a right side beam provided at the upper end of the right door, wherein the left side beam and the right side beam are made of long material that curves upward over the entire area from the front end to the rear end, and whose front and rear halves have symmetrical curvatures with a dividing line halfway in the fore-and-aft direction.

[0017] The elongated material may be formed so that the radius of curvature at a middle portion in the longitudinal direction is larger than the radius of curvature at both ends in the longitudinal direction.

[0018] The long material may have a larger radius of curvature between both longitudinal ends and a middle portion than the both longitudinal ends and a smaller radius of curvature than the middle portion in the longitudinal direction.

[0019] The elongated material may have, at either end of the front panel, the rear panel, the left door, or the right door, a main seal surface facing the inner surface of the end and a sub-seal surface facing the end face of the end, and the end may be provided with a door seal having a main lip that seals the main seal surface of the elongated material and a sub-lip that seals the sub-seal surface of the elongated material.

[0020] According to the cabin of the present invention, the frame material is common to the left and right sides, thereby making it possible to suppress increases in the number of steps and costs.

[0021] 8 is a schematic diagram showing a procedure for processing a left front pillar from a long material for a front pillar. 9 is a schematic diagram showing a procedure for processing a left front pillar from a long material for a front pillar. 10 is a schematic diagram showing a procedure for processing a left front pillar from a long material for a front pillar. 11 is a schematic diagram showing a procedure for processing a left front pillar from a long material for a front pillar. 12 is a schematic diagram showing a procedure for processing a left front pillar from a long material for a front pillar. 13 is a schematic diagram showing a procedure for processing a right front pillar from a long material for a front pillar. 14 is a schematic diagram showing a procedure for processing a right front pillar from a long material for a front pillar. 15 is a schematic diagram showing a procedure for processing a left front pillar from a long material for a front pillar. 16 is a schematic diagram showing a procedure for processing a right front pillar from a long material for a front pillar. 17 is a schematic diagram showing a procedure for processing a right front pillar from a long material for a front pillar. 18 is a schematic diagram showing a procedure for processing a right front pillar from a long material for a front pillar. 13A and 13B are schematic diagrams showing a procedure for processing a right front pillar from a long material for a front pillar. 13B are schematic diagrams showing a procedure for processing a right front pillar from a long material for a front pillar. 13C are a left side view of a left side beam, a right side view of a right side beam, a plan view of the left side beam, a right side view of the left side beam, a left side view of the left side beam, a cross-sectional view of the left side beam taken along line D-D in FIG. 13A and 13B are schematic diagrams showing a procedure for processing a left side beam and a right side beam from a long material for a side beam. 13C are a left side view of a left rear pillar, a right side view of a right rear pillar, a cross-sectional view of the left side beam with an enlarged view of an attachment portion of a door seal, and a cross-sectional structure (irregular cross section) of a left front pillar at an enlarged scale. 13D are a diagram showing an irregular cross section of a left front pillar of the present invention, a diagram showing a cross-section of a conventional left front pillar, a cross-sectional view of a left front pillar according to another embodiment, a cross-sectional view of a irregular cross section of a left front pillar according to another embodiment. 1A and 1B are bird's-eye views and top-down views showing the connection between the right side beam and the rear beam at the upper end of the right rear pillar, respectively.Fig. 1 is a bird's-eye view showing the connection state between the right side beam and the front beam at the upper end of the right front pillar. Fig. 2 is an enlarged rear view of the support structure. Fig. 3 is an enlarged rear view of the support structure when the brake pedal, steering column, interlock release pedal, etc. are removed. Fig. 4 is an enlarged front view of the support structure. Fig. 5 is a cross-sectional view of the support structure cut halfway in the left-right direction.

[0022] The cabin 1 of this embodiment will be described below with reference to the drawings as appropriate.

[0023] 1 shows a side view of a tractor 2 having a cabin 1 according to the present embodiment. In the present embodiment, the tractor 2 is exemplified as a work machine (vehicle) on which the cabin 1 of the present invention is mounted. However, a wheel loader, a backhoe, or the like may also be used as the work machine on which the cabin 1 of the present invention is mounted.

[0024] In this specification, the direction of arrow A1 in FIG. 1 (the forward direction of the tractor 2) will be referred to as the forward direction, the direction of arrow A2 in FIG. 1 (the reverse direction of the tractor 2) will be referred to as the backward direction, and the direction of arrow A3 in FIG. 1 will be referred to as the front-to-rear direction. Therefore, the front of FIG. 1 corresponds to the left when describing the tractor 2 and the cabin 1, and the back of FIG. 1 corresponds to the right when describing the tractor 2 and the cabin 1. These directions correspond to the directions as seen by an operator OP (hereinafter, the person who drives and operates the tractor 2 while riding in the driver's seat 6) of the tractor 2. The tractor 2 and the cabin 1 will be described with the horizontal direction perpendicular to the front-to-rear direction indicated by arrow A3 as the width direction. Furthermore, the direction from the center of the tractor 2 in the width direction toward the right or left will be described as the width direction outward. In other words, the width direction outward refers to the direction away from the center of the tractor 2 in the width direction. The direction opposite to the width direction outward will be described as the width direction inward. In other words, the inward direction in the width direction is the direction approaching the center of the tractor 2 in the width direction.

[0025] 1, the tractor 2 has a travelable machine body (vehicle body) 3. The machine body 3 has a prime mover E1 and a transmission case 4.

[0026] The prime mover E1 generates driving force to propel the machine body 3, and in this embodiment, a diesel engine is used. The prime mover E1 is located at the front of the tractor 2 and is covered by a bonnet 10. The bonnet 10 has a curved top surface that protrudes slightly upward, and has a space inside that can store the prime mover E1. In the tractor 2 of this embodiment, the prime mover E1 is stored in the space inside the bonnet 10.

[0027] It should be noted that, instead of the diesel engine used in this embodiment, an electric motor may be used as the prime mover E1, or a hybrid type that combines a diesel engine and an electric motor may be used.

[0028] The transmission case 4 is configured by directly connecting, for example, a flywheel housing that accommodates a flywheel, a clutch housing 107 (see Figures 1 and 27) that accommodates a clutch that intermittently transmits the power of the prime mover E1 transmitted via the flywheel, and a transmission case that accommodates a transmission that changes the speed of the power transmitted via the clutch.

[0029] As shown in Fig. 1, the tractor 2 has a traveling device 5 that supports the machine body 3 so that it can travel. The traveling device 5 of the tractor 2 of this embodiment illustrated in Fig. 1 is a wheel type (four-wheel type) that has a left front wheel 11L and a right front wheel 11R arranged at the front of the machine body 3, and a left rear wheel 12L and a right rear wheel 12R arranged at the rear of the machine body 3. In other words, the tractor 2 of this embodiment has a traveling device 5 that travels on four wheels: the left front wheel 11L, the right front wheel 11R, the left rear wheel 12L, and the right rear wheel 12R.

[0030] 1, the cabin 1 is a room where an operator OP enters to drive and operate the machine body 3, and in this embodiment, is mounted at the rear of the machine body 3. A driver's seat 6 where the operator OP sits is provided at the rear of the interior of the cabin 1 (referred to as the cabin interior). A steering handle 7 for steering, for example, a left front wheel 11L and a right front wheel 11R is provided in front of the driver's seat 6.

[0031] As shown in Figures 1 and 2, the cabin 1 has a cabin frame 8 in which long frame materials are combined in a three-dimensional, tower-like configuration. In other words, the cabin frame 8 forms the framework (exoskeleton) of the cabin 1 and has a plurality of long frame materials. In addition, panel members such as a front panel 31 and door panels 27 (described later) are arranged between the three-dimensional, tower-like combined frame materials in the cabin frame 8. In addition, a roof 9 is provided on top of the cabin frame 8. As shown in Figure 2, the cabin frame 8 of this embodiment is a four-pillar type that does not have a center pillar (quarter pillar).

[0032] As shown in Figures 2 to 6 (particularly in detail in Figure 2), the cabin frame 8 has a plurality of long frame members. In this embodiment, the cabin frame 8 is made up of eleven frame members: a left front pillar 13L, a right front pillar 13R, a left rear pillar 14L, a right rear pillar 14R, a front beam 15, a rear beam 16, a rear lower frame 17 (rear beam), a left side beam 18L, a right side beam 18R, a left side lower beam 19L (left side lower frame), and a right side lower beam 19R (right side lower frame). Each frame member that makes up the cabin frame 8 will be described in detail below.

[0033] As shown in detail in FIGS. 2 to 5 , a left front pillar 13L and a right front pillar 13R are provided in the front portion of the cabin frame 8 (in front of the driver's seat 6). The left front pillar 13L and the right front pillar 13R are arranged side by side with a gap in the width direction, and both are arranged to extend in the up-down direction. The left front pillar 13L is provided at the left front corner of the cabin 1. The right front pillar 13R is provided at the right front corner of the cabin 1. A front beam 15 spans between the upper portion of the left front pillar 13L and the upper portion of the right front pillar 13R. In other words, the upper portion of the left front pillar 13L and the upper portion of the right front pillar 13R are connected laterally by the front beam 15.

[0034] In the following description, the left front pillar 13L and the right front pillar 13R may be collectively referred to as the front pillars 13.

[0035] As shown in detail in Figures 2, 3, 5, and 6, a left rear pillar 14L and a right rear pillar 14R are provided at the rear of the cabin frame 8 (behind the driver's seat 6). The left rear pillar 14L and the right rear pillar 14R are arranged side by side with a gap in the width direction and both extend vertically. The left rear pillar 14L is provided at the left rear corner of the cabin 1. The right rear pillar 14R is provided at the right rear corner of the cabin 1. A rear beam 16 spans between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. In other words, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected laterally by the rear beam 16. A rear lower frame 17 spans between the lower part of the left rear pillar 14L and the lower part of the right rear pillar 14R. That is, the lower portion of the left rear pillar 14L and the lower portion of the right rear pillar 14R are connected to each other laterally by the rear lower frame 17.

[0036] In the following description, the left rear pillar 14L and the right rear pillar 14R may be collectively referred to as the rear pillar 14.

[0037] As shown in detail in Figures 2, 3, and 5, a left side beam 18L and a right side beam 18R are provided on the upper part of the cabin frame 8. The left side beam 18L and the right side beam 18R are arranged side by side with a gap in the width direction and are both provided to extend in the fore-and-aft direction. The left side beam 18L is curved so that its midpoint in the fore-and-aft direction bulges upward compared to its front and rear ends. The right side beam 18R is curved so that its midpoint in the fore-and-aft direction bulges upward compared to its front and rear ends.

[0038] The left side beam 18L spans between an upper portion of the left front pillar 13L and an upper portion of the left rear pillar 14L. In other words, the upper portion of the left front pillar 13L and the upper portion of the left rear pillar 14L are connected in the front-rear direction by the left side beam 18L.

[0039] The right side beam 18R spans between the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R. In other words, the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R are connected in the front-rear direction by the right side beam 18R.

[0040] In the following description, the left side beam 18L and the right side beam 18R may be collectively referred to as the side beams 18.

[0041] 2 and 3, a left side lower beam 19L and a right side lower beam 19R are provided at the bottom of the cabin frame 8. The left side lower beam 19L and the right side lower beam 19R are arranged side by side with a gap in the width direction.

[0042] The left side lower beam 19L is formed in an arc extending downward and forward from the lower part of the left rear pillar 14L. That is, the left side lower beam 19L extends downward as it extends forward from the lower part of the left rear pillar 14L. The lower end of the left side lower beam 19L, which extends downward, is connected in the longitudinal direction to the lower end of the left front pillar 13L via a left connecting frame 20L.

[0043] The right side lower beam 19R is formed in an arc extending downward and forward from the lower part of the right rear pillar 14R. That is, the right side lower beam 19R extends downward as it extends forward from the lower part of the right rear pillar 14R. The lower end of the right side lower beam 19R, which extends downward, is connected in the longitudinal direction to the lower end of the right front pillar 13R via a right connecting frame 20R.

[0044] Hereinafter, the left side lower beam 19L and the right side lower beam 19R will be collectively referred to as the side lower beam 19.

[0045] 2, a left rear wheel fender 21L that covers the left rear wheel 12L is fixed to the lower surface of the left side lower beam 19L and the lower end of the left rear pillar 14L. Also, a right rear wheel fender 21R that covers the right rear wheel 12R is fixed to the lower surface of the right side lower beam 19R and the lower end of the right rear pillar 14R.

[0046] As shown in detail in Figures 2, 4, 5, and 6, a front beam 15 is provided at the front of the upper portion of the cabin frame 8, and a rear beam 16 is provided at the rear.

[0047] The front beam 15 and the rear beam 16 are arranged side by side with a gap in the fore-and-aft direction, and are both formed as long frame members extending in the left-right direction. The front beam 15 is curved so that its midpoint in the left-right direction bulges upward compared to its left and right ends. The rear beam 16 extends linearly in the left-right direction with almost no change in height in the up-down direction.

[0048] The front beam 15 spans between the upper part of the left front pillar 13L and the upper part of the right front pillar 13R. In other words, the upper part of the left front pillar 13L and the upper part of the right front pillar 13R are connected laterally by the front beam 15.

[0049] The rear beam 16 spans between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. In other words, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected laterally by the rear beam 16.

[0050] In other words, the cabin frame 8 of this embodiment is formed by combining frame materials such as the above-mentioned left front pillar 13L, right front pillar 13R, left rear pillar 14L, right rear pillar 14R, front beam 15, rear beam 16, rear lower frame 17, left side beam 18L, right side beam 18R, left side lower beam 19L, and right side lower beam 19R.

[0051] 2 and 5, a floor sheet 22 is provided between the left rear wheel fender 21L and the right rear wheel fender 21R. The floor sheet 22 is arranged horizontally below the driver's seat 6, and the driver's seat 6 is attached on top of this floor sheet 22. The rear portion of the floor sheet 22 extends obliquely rearward and upward, and is located behind the driver's seat 6. A step 23 that forms a floor at a position lower than the floor sheet 22 is provided forward from the front lower end of the floor sheet 22. The feet of an operator OP seated in the driver's seat 6 are placed on the step 23.

[0052] 1, 3, 4, and 6, the roof 9 is disposed on top of the cabin frame 8 and is capable of preventing wind, rain, and direct sunlight from entering the cabin 1. The roof 9 has an inner roof 24 that forms the ceiling portion and the like inside the cabin 1, and an outer roof 25 that forms the upper wall and the like of the ceiling portion. A hollow space is formed between the inner roof 24 and the outer roof 25, and a space is formed in which an air conditioning device 26 that conditions the air inside the cabin can be installed.

[0053] 1, 2, and 5, the cabin 1 of this embodiment is configured to allow the operator OP to board from both the left and right sides, and has a left boarding / alighting opening 28L on the left side of the cabin 1 and a right boarding / alighting opening 28R on the right side of the cabin 1. A left door 27L (left door panel) that closes the left boarding / alighting opening 28L is provided at the left boarding / alighting opening 28L. A right door 27R (right door panel) that closes the right boarding / alighting opening 28R is provided at the right boarding / alighting opening 28R.

[0054] The left entrance 28L is an opening surrounded by the left front pillar 13L, left side beam 18L, left rear pillar 14L, left side lower beam 19L, and left connecting frame 20L, and opens to the left. The left entrance 28L can be closed by a left door 27L. The left door 27L is supported by two door hinges, one above and one below, on the left rear pillar 14L. The two door hinges are a first door hinge 29L provided on the upper part of the left rear pillar 14L and a second door hinge 30L provided below the first door hinge 29L. In other words, the left entrance 28L can be opened and closed by swinging the front end of the left door 27L left and right relative to the rear end, where the first door hinge 29L and the second door hinge 30L are provided.

[0055] The right entrance 28R is an opening surrounded by the right front pillar 13R, right side beam 18R, right rear pillar 14R, right side lower beam 19R, and right connecting frame 20R, and opens to the right. The right entrance 28R can be closed by a right door 27R. The right door 27R is supported by two door hinges, one above and one below, on the right rear pillar 14R. The two door hinges are a first door hinge 29R provided on the top of the right rear pillar 14R and a second door hinge 30R provided below the first door hinge 29R. In other words, the right entrance 28R can be opened and closed by swinging the front end of the right door 27R left and right relative to the rear end, where the first door hinge 29R and the second door hinge 30R are provided.

[0056] The left door 27L and the right door 27R described above are formed of light-transmitting panels such as tempered glass or acrylic glass, ensuring good visibility of the outside of the vehicle from inside the cabin 1.

[0057] As shown in FIG. 5 , the cabin 1 of this embodiment includes a front panel 31 at the front of the cabin frame 8 and a rear panel 32 at the rear of the cabin frame 8 .

[0058] The front panel 31 is disposed between a left front pillar 13L and a right front pillar 13R disposed at a distance from each other on the left and right sides, and is supported on the left and right sides by the left front pillar 13L and the right front pillar 13R. The upper edge of the front panel 31 is fixed to a front beam 15 disposed above the front panel 31. Like the left door 27L and the right door 27R described above, the front panel 31 is formed from a light-transmitting panel such as tempered glass or acrylic glass, and good visibility of the outside of the vehicle (forward) from inside the cabin 1 can be ensured.

[0059] The front panel 31 of this embodiment is formed into a curved surface that bulges forward. In other words, when the front panel 31 is cut horizontally, the horizontal cross section of the front panel 31 has an arc shape in which the center in the left-right direction protrudes forward compared to the left and right ends. Furthermore, when the front panel 31 is cut vertically, the vertical cross section of the front panel 31 has an arc shape in which the center in the up-down direction protrudes forward compared to the upper and lower ends. By forming the front panel 31 into a curved surface that bulges forward, it is possible to improve visibility from inside the cabin 1 to the front outside the vehicle, particularly downward.

[0060] Next, the configuration of the left front pillar 13L and the right front pillar 13R will be described in detail.

[0061] Fig. 8A shows a left side view of the left front pillar 13L, and Fig. 8B shows a right side view of the right front pillar 13R. As can be seen by comparing Fig. 8A and Fig. 8B, the left front pillar 13L and the right front pillar 13R are formed symmetrically with respect to a vertical reference plane S (see Fig. 6) that passes through the center of the cabin 1 in the width direction and is perpendicular to the width direction.

[0062] As shown in Figures 4 to 6, the reference plane S is a vertical plane that passes through the center of the cabin 1 in the width direction and is perpendicular to the width direction, and is located midway between the left and right directions of the cabin 1.

[0063] 8A and 8B, the left front pillar 13L and the right front pillar 13R are formed long in the vertical direction and curved in an arc so that the center in the vertical direction protrudes forward compared to the upper and lower ends. Mirror mounting portions 33 for mounting door mirrors and the like are provided on the upper portions of the left front pillar 13L and the right front pillar 13R.

[0064] When the left front pillar 13L shown in Fig. 8A is cut midway up and down along the cutting line connecting "C" and "C" in the figure, a cross section such as that shown in Fig. 9A is obtained. Similarly to the left front pillar 13L, when the right front pillar 13R is cut midway up and down at the same height as the left front pillar 13L along the cutting line connecting "C'" and "C'" in the figure, a cross section such as that shown in Fig. 9B is obtained.

[0065] The cross section of the left front pillar 13L in Figure 9A and the cross section of the right front pillar 13R in Figure 9B are both irregular cross sections, and the cross-sectional shapes are not congruent even when they are inverted or rotated. Note that in this specification, an "irregular cross section" refers to a shape such that, even when inverted about any line or rotated around any point, the shape before inversion or rotation is not the same as the shape after inversion or rotation, in other words, a shape that has no line symmetry or rotational symmetry whatsoever.

[0066] The left front pillar 13L and the right front pillar 13R do not have any line symmetry or rotational symmetry individually. However, if the cross section of the left front pillar 13L is flipped left to right, it becomes congruent with the cross section of the right front pillar 13R, and if the cross section of the right front pillar 13R is flipped left to right, it becomes congruent with the cross section of the left front pillar 13L. In other words, the cross sections of the left front pillar 13L and the right front pillar 13R are in a line symmetrical relationship with each other.

[0067] The cross section of the left front pillar 13L and the cross section of the right front pillar 13R are symmetrical left to right because the left front pillar 13L and the right front pillar 13R are formed from the same long material. In other words, the left front pillar 13L and the right front pillar 13R are processed from the same original long material (front pillar long material 34F).

[0068] Next, the long material will be described.

[0069] In this embodiment, similar to the left front pillar 13L and right front pillar 13R, the left side beam 18L and right side beam 18R, and the left rear pillar 14L and right rear pillar 14R also use long materials of the same shape as the original material common to the left and right frame materials.

[0070] Hereinafter, the long members of the left front pillar 13L and the right front pillar 13R will be referred to as long members for the front pillars 34F to distinguish them from the long members of the left rear pillar 14L and the right rear pillar 14R (long members for rear pillars 34R) and the long members of the left side beam 18L and the right side beam 18R (long members for side beams 34S) described below.

[0071] As shown in FIG. 10A , the front pillar elongated member 34F is formed from a tubular material that is curved so that the vertical midpoint bulges forward relative to the upper and lower ends. In this embodiment, the front pillar elongated member 34F is curved with the same curvature throughout its entire region from the top to the bottom, and the curvatures of the upper and lower halves are symmetrical across the vertical midpoint. The front pillar elongated member 34F has a non-circular cross-section as shown in FIGS. 9A and 9B and is hollow. The left front pillar 13L and the right front pillar 13R are selectively processed by changing the method of cutting the ends of the same shaped front pillar elongated member 34F. Specifically, when the left front pillar 13L is processed by cutting one longitudinal end of the front pillar elongated member 34F, the right front pillar 13R can be obtained by cutting the ends in the opposite manner. The procedure for selectively processing the left front pillar 13L and the right front pillar 13R by cutting the same shaped elongated front pillar material 34F in the opposite manner will be described below.

[0072] 10A and 10B are diagrams showing the procedure for processing the left front pillar 13L from the long front pillar material 34F. In Fig. 10A and Fig. 10B, processing is performed in the order from Fig. 10A to Fig. 10B.

[0073] As shown in FIG. 10A, the front pillar elongated member 34F is formed as a tubular member that is longer in the longitudinal direction than the left front pillar 13L and the right front pillar 13R.

[0074] 10B, when processing the left front pillar 13L from the long front pillar material 34F, the long front pillar material 34F is cut along a first cut line 35 (see FIG. 10A) slightly below the upper end of the long front pillar material 34F, and a first end piece 36 located above the first cut line 35 is cut and removed. Also, the long front pillar material 34F is cut along a second cut line 37 (see FIG. 10A) slightly above the lower end of the long front pillar material 34F, and a second end piece 38 located below the second cut line 37 is cut and removed.

[0075] As shown in Figure 10C, after removing the first end piece 36 and the second end piece 38 by cutting as shown in Figure 10B, the left front pillar 13L can be processed by attaching a mirror mounting portion 33 or the like to a predetermined position on the top of the long material 34F for the front pillar after cutting.

[0076] Next, the procedure for processing the right front pillar 13R from the long front pillar material 34F will be described with reference to Figures 11A to 11D. Note that in Figures 11A to 11D, processing is performed in the order from Figure 11A to Figure 11D.

[0077] As shown in Figure 11A, first, a front pillar elongated material 34F similar to that shown in Figure 10A is prepared. Here, the front pillar elongated material 34F of this embodiment has an arc-shaped curve with the same curvature from the top to the bottom. In other words, the front pillar elongated material 34F has a structure that is vertically symmetrical with respect to the inversion reference line M, which passes horizontally midway between the top and bottom ends (the middle between the top and bottom). Therefore, even if the front pillar elongated material 34F is inverted upside down across the inversion reference line M, the curvature and other curved conditions do not change before and after inversion.

[0078] However, the front pillar elongated material 34F has an irregular cross section, for example, as shown in Fig. 9A. When the front pillar elongated material 34F is inverted upside down at the inversion reference line M, the irregular cross section is also inverted upside down. The irregular cross section shown in Fig. 9A changes to the irregular cross section shown in Fig. 9B. The front pillar elongated material 34F obtained in this manner (front pillar elongated material 34F after inversion) is as shown in Fig. 11B.

[0079] As shown in Figure 11C, after being inverted, the long material 34F for the front pillar is cut along a first cut line 35 below the upper end of the long material 34F for the front pillar to remove the first end piece 36, in the same way as when processing the left front pillar 13L, and then cut along a second cut line 37 above the lower end of the long material 34F for the front pillar to remove the second end piece 38.

[0080] In addition, the first cut line 35 and the second cut line 37 when processing the right front pillar 13R are the same as those when processing the left front pillar 13L in terms of the inclination direction and the position from both ends of the long material for the front pillar 34F (longitudinal position).

[0081] As shown in Figure 11D, after removing the first end piece 36 and the second end piece 38, a mirror mounting portion 33 or the like is attached to a predetermined position on the top of the cut long material 34F for the front pillar, and the right front pillar 13R shown in Figure 11D can be processed.

[0082] In this embodiment, both ends of the front pillar elongated member 34F in the longitudinal direction are cut off, but only one of the longitudinal ends may be cut off. Also, the first cut line 35 and the second cut line 37 may be cut along a cutting line other than a straight line, for example, a curved line or a cutting line that is a combination of a plurality of curves and straight lines.

[0083] In other words, the left front pillar 13L and the right front pillar 13R have the same curvature and cross-sectional shape except for the longitudinal ends where the cuts are made.

[0084] The above-described long front pillar material 34F can be processed into either the left front pillar 13L or the right front pillar 13R, depending on whether or not it is inverted longitudinally before cutting. In other words, the long front pillar material 34F is a raw material (a common raw material for both the left front pillar 13L and the right front pillar 13R) that can be selectively processed into either the left front pillar 13L or the right front pillar 13R, depending on whether or not it is inverted. Therefore, by simply molding and bending the common (same-shaped) long front pillar material 34F, only one molding and bending process is required. However, with conventional processing methods, the left front pillar 13L and the right front pillar 13R had to be individually processed using separate dies or bent separately, which required a great deal of time and cost for the molding and bending processes. Therefore, in the cabin 1 of this embodiment, by using the long front pillar material 34F as the raw material common to the left front pillar 13L and the right front pillar 13R, it is possible to suppress an increase in manufacturing costs.

[0085] In the above description, the left front pillar 13L, the right front pillar 13R, and the front pillar elongated member 34F are described based on their orientation in the vertical direction, in other words, the orientation when they are attached to the cabin 1. However, the first end piece 36 and the second end piece 38 may be removed or the mirror mounting portion 33 may be attached to the left front pillar 13L, the right front pillar 13R, and the front pillar elongated member 34F in a state where they are oriented horizontally or tilted relative to the horizontal. In this case, it is preferable to invert the midpoint of the front pillar elongated member 34F in the longitudinal direction about an inversion reference line M extending perpendicular to the longitudinal direction.

[0086] Incidentally, the left front pillar 13L and the right front pillar 13R described above are arc-shaped, curved with the same curvature (single curvature) from their top to bottom ends, and the long front pillar material 34F, which is the original material from which the left front pillar 13L and the right front pillar 13R are processed, is also formed in an arc-shaped shape, curved with the same curvature (single curvature) from their top to bottom ends.

[0087] However, the elongated material does not necessarily have to be curved with the same curvature throughout the entire length as long as it has symmetry such that the curvature is equal before and after reversal when the material is reversed across the reversal reference line M. For example, the elongated material does not necessarily have to have a single curvature as long as it has a curvature such that the curvature at a position a certain distance in one direction in the lengthwise direction is equal to the curvature at a position the same distance in the other direction in the lengthwise direction (a curvature that is line-symmetrical with respect to the reversal reference line M). An example of such an elongated material is the elongated side beam elongated material 34S for the left side beam 18L and the right side beam 18R described above.

[0088] Next, the configurations of the left side beam 18L and the right side beam 18R will be described in detail.

[0089] As shown in FIG. 2, a left side beam 18L is provided above the left door 27L, and a right side beam 18R is provided above the right door 27R.

[0090] Fig. 12A shows a left side view of the left side beam 18L, and Fig. 12B shows a right side view of the right side beam 18R. As can be seen by comparing Fig. 12A and Fig. 12B, the left side beam 18L and the right side beam 18R are formed symmetrically with respect to a vertical reference plane S (see Figs. 4 to 6) that passes through the center of the cabin 1 in the width direction and is perpendicular to the width direction.

[0091] The left side beam 18L and the right side beam 18R have the same basic configuration except that they are arranged in opposite positions. Hereinafter, the structure of the side beam 18 of this embodiment will be described using the left side beam 18L as a representative example.

[0092] 13A and 13B show a comparison of views of the left side beam 18L from different viewpoints: Fig. 13A is a plan view of the left side beam 18L, Fig. 13B is a right side view of the left side beam 18L, and Fig. 13C is a left side view of the left side beam 18L.

[0093] As shown in Fig. 13A, the upper surface of the left side beam 18L has an appearance of an elongated rectangle extending substantially linearly in the fore-aft direction. More precisely, the upper surface of the left side beam 18L has a gently curved arc shape such that the fore-aft middle portion bulges inward in the width direction. In other words, when considering the case where the left side beam 18L is assembled into the cabin 1, the distance along the width direction between the fore-aft middle portion of the left side beam 18L and the fore-aft middle portion of the right side beam 18R is shorter than the distance along the width direction between the front end of the left side beam 18L and the front end of the right side beam 18R (see Fig. 5).

[0094] Screw holes 80 for attaching the roof 9 are formed on the upper surface of the left side beam 18L at a position slightly rearward of the front end and at a position slightly forward of the rear end.

[0095] FIG. 14 shows a cross-sectional view of the left side beam 18L taken along line DD in FIG. 13A at the center in the front-rear direction.

[0096] As shown in Figure 14, the cross section of the left side beam 18L is a hollow space surrounded on three sides by three walls: an upper wall 39, a lower wall 44, and a left wall (outer wall). In other words, the cross section of the left side beam 18L is generally U-shaped or Σ-shaped, opening toward the interior. In principle, no wall is provided on the right side of the left side beam 18L, but a left first fixing plate 42L is provided slightly rearward of the midpoint in the fore-aft direction (see Figure 13B).

[0097] If the cross section of the left side beam 18L is formed to be approximately U-shaped or approximately Σ-shaped, when processing the left side beam 18L, a processing die is pressed against the outer side surface in the width direction and press processing is performed from the inner side in the width direction, which makes it possible to easily process the first outer wall portion 40, the connecting wall portion 43, and the second outer wall portion 41 in a single processing operation. Furthermore, by employing press processing, the left side beam 18L can be easily formed to be approximately linear in the fore-and-aft direction or to be bulged inward in the width direction in a gentle arc shape.

[0098] The left side surface of the left side beam 18L is formed in a stepped shape. Specifically, the left side surface of the left side beam 18L includes a first outer wall portion 40 that is connected to the outer end (outer end) of the upper wall portion 39 in the width direction and is formed as a wall surface that stands up in the vertical direction, and a second outer wall portion 41 that is disposed inward in the width direction from the first outer wall portion 40 and is formed to stand up in the vertical direction. A connecting wall portion 43 that connects the first outer wall portion 40 and the second outer wall portion 41 is provided between the first outer wall portion 40 and the second outer wall portion 41.

[0099] The connecting wall 43 connects the lower end of the first outer wall 40 and the upper end of the second outer wall 41 in a substantially horizontal direction. In the case of the left side beam 18L, the connecting wall 43 is formed in a direction that is inclined slightly upward to the left with respect to the horizontal direction. Although not shown, in the case of the right side beam 18R, the connecting wall 43 is formed in a direction that is inclined slightly upward to the right with respect to the horizontal direction. The lower wall 44 described above is provided at the lower end of the second outer wall 41 so as to extend inward in the width direction.

[0100] As shown in Figure 13B, the right side of the left side beam 18L, i.e., the side of the left side beam 18L facing inward in the width direction, has an arc-like appearance with a curved, upwardly bulging central portion in the front-to-rear direction. An upper wall portion 39 is provided at the top of the right side of the left side beam 18L, and a lower wall portion 44 is provided at the bottom of the right side. The left side beam 18L is open to the right, and the right ends of the upper wall portion 39 and the lower wall portion 44 are spaced apart at a substantially constant vertical distance.

[0101] A left first fixing plate 42L is provided on the right side surface of the left side beam 18L, slightly rearward of the longitudinal center. The left first fixing plate 42L is a member that vertically connects the right end (the widthwise inner end) of the upper wall portion 39 to the right end (the widthwise inner end) of the lower wall portion 44 (see FIG. 14 ) and is disposed to partially close the opening of the left side beam 18L, which opens inward in the width direction. The left first fixing plate 42L is provided to secure a left reinforcing member 49L (described later), i.e., a left reinforcing member 49L that connects the left rear pillar 14L, the rear beam 16, and the left side beam 18L in a diagonal brace manner. By vertically connecting the right end of the upper wall portion 39 to the right end of the lower wall portion 44 with the left first fixing plate 42L, the left side beam 18L is less likely to deform, thereby increasing the load-bearing capacity of the cabin 1.

[0102] A first welding auxiliary part 50 is provided at the front end of the right side surface of the left side beam 18L. The first welding auxiliary part 50 is a plate member that stands upright in the vertical direction and is attached so as to be inclined toward the left rear from the left wall part (outer wall part) of the left side beam 18L.

[0103] As shown in FIG. 13C , the left side surface of the left side beam 18L, i.e., the left side surface of the left side beam 18L facing outward in the width direction, has an arc-shaped appearance with a curved, upwardly bulging central portion in the front-to-rear direction, similar to the right side surface. A first outer wall portion 40 is provided at the upper portion of the left side surface of the left side beam 18L, and a second outer wall portion 41 is provided at the lower portion of the left side surface. The first outer wall portion 40 is formed to have a longer length in the front-to-rear direction than the second outer wall portion 41. Therefore, the front end of the first outer wall portion 40 protrudes forward beyond the front end of the second outer wall portion 41, and the rear end of the first outer wall portion 40 protrudes rearward beyond the rear end of the second outer wall portion 41.

[0104] Next, the configuration of the side beam elongated member 34S will be described in detail.

[0105] 15, the left side beam 18L and the right side beam 18R are formed from the same elongated side beam material 34S that is curved upward and bulges outward. In other words, the left side beam 18L and the right side beam 18R share the same base material, the elongated side beam material 34S.

[0106] The long member 34S for the side beam is formed so that the front curvature and rear curvature are symmetrical in the front-to-rear direction with respect to the inversion reference line M, which intersects the midpoint in the front-to-rear direction (longitudinal direction) perpendicular to the front-to-rear direction.

[0107] Specifically, while the front pillar elongated member 34F has a uniform curvature throughout its entire length, the side beam elongated member 34S has a curvature that varies in multiple stages depending on its longitudinal position. In this embodiment, the curvature of the underside of the side beam elongated member 34S varies in four stages. For example, the front pillar elongated member 34F has a curvature of R1 on the underside in the region immediately before and after the inversion reference line M. The curvature of the underside is R2 on the region immediately adjacent to and on the widthwise outer side of the region with curvature R1. The curvature of the underside is R3 on the region immediately adjacent to and on the widthwise outer side of the region with curvature R2. The curvature of the underside changes to R4 on the region immediately adjacent to and on the widthwise outer side of the region with curvature R3. In this way, the underside of the side beam elongated member 34S in this embodiment has a curvature of any of R1, R2, R3, and R4.

[0108] That is, in the case of the elongated side beam member 34S of this embodiment, the curvature is the same when the distance forward from the inversion reference line M in the fore-and-aft direction and the distance rearward from the inversion reference line M are equal, with the inversion reference line M as the reference line. Furthermore, as the distance forward or rearward from the inversion reference line M changes, the curvature of the underside also changes in multiple stages (four stages in this embodiment). The multi-stage change in curvature increases with increasing distance from the inversion reference line M in the fore-and-aft direction. The multi-stage curvature is arranged to be symmetrical in the fore-and-aft direction with respect to the inversion reference line M. Therefore, even if the elongated side beam member 34S is inverted front-to-back across the inversion reference line M, which is located midway in the fore-and-aft direction, the shape does not change before and after inversion, just like the elongated front pillar member 34F.

[0109] In this embodiment, the curvature of each region of the elongated side beam member 34S is such that the region of curvature R1 has the smallest curvature, the region of curvature R2 has the next smallest curvature, and the regions of curvature R3 and R4 have the largest curvature. In other words, the region of curvature R1 has a small curvature so as to ensure a sufficient volume of space inside the roof 9 of the cabin 1. In contrast, the curvature of the elongated side beam member 34S in the region of curvature R4 is formed to a value close to the curvature of the front pillar 13, so that the side beam 18 and the front pillar 13 are smoothly connected without creating a bent appearance. This allows the front pillar 13 and the side beam 18 to be smoothly connected, eliminating the appearance of a bent portion, thereby achieving a cabin 1 with an excellent design.

[0110] Furthermore, in the side beam elongated member 34S of this embodiment, the curvatures R2 and R3 are smaller than the curvature R1 and larger than the curvature R4. If an area of ​​curvature R2 or R3 with an intermediate value (smaller than R1 and larger than R4) is provided between the area of ​​curvature R1 and the area of ​​curvature R4, the area of ​​curvature R1 and the area of ​​curvature R4 will be smoothly connected without giving the impression of being bent, and it will be possible to obtain an appearance of excellent design for the cabin 1, similar to the case described above.

[0111] When processing the left side beam 18L from the elongated side beam material 34S, the first end piece 36 is cut and removed from the front end of the elongated side beam material 34S, and the second end piece 38 is cut and removed from the rear end. Then, by attaching the first left fixing plate 42L and the first left welding auxiliary part 50L to the inner side surface of the elongated side beam material 34S in the width direction by means of welding or the like, the left side beam 18L can be processed.

[0112] On the other hand, when forming the right side beam 18R from the elongated side beam member 34S, the elongated side beam member 34S is rotated 180 degrees horizontally while maintaining its upwardly curved position, switching the front and rear directions. After rotating the elongated side beam member 34S in this manner, the first end piece 36 is cut and removed from the front end of the elongated side beam member 34S, and the second end piece 38 is cut and removed from the rear end of the elongated side beam member 34S, as in the case of forming the left side beam 18L. Then, by attaching the right first fixing plate 42R and the second welding auxiliary portion 51 to the inner side surface of the elongated side beam member 34S by welding or other means, the right side beam 18R can be formed.

[0113] In this embodiment, both longitudinal ends of the side beam elongated member 34S are cut off, but only one longitudinal end may be cut off.

[0114] In other words, the left side beam 18L and the right side beam 18R in this embodiment are formed from the side beam elongated members 34S (elongated members) having the same shape in all parts except for the longitudinal ends.

[0115] The side beam elongated material 34S described above can be processed into either the left side beam 18L or the right side beam 18R, depending on whether it is rotated (flipped) longitudinally before cutting. In other words, the side beam elongated material 34S is a raw material (a common raw material) for both the left side beam 18L and the right side beam 18R, which can be selected depending on whether it is flipped. Therefore, if the side beam elongated material 34S is formed and bent using a single die, the work of die forming and bending can be completed in one go. However, with conventional processing methods, the left side beam 18L and the right side beam 18R must be formed using separate dies or bent separately, which requires a great deal of time and cost for the die forming and bending work. Therefore, the cabin 1 of this embodiment can suppress increases in manufacturing costs by using the long material 34S for the side beams as the raw material common to the left and right frame materials, i.e., the left side beam 18L and the right side beam 18R.

[0116] Next, the configuration of the left rear pillar 14L and the right rear pillar 14R will be described in detail.

[0117] 5, the cabin 1 of this embodiment includes a rear panel 32 disposed behind the driver's seat 6, a door panel for a left door 27L and a door panel for a right door 27R disposed to the left and right of the driver's seat 6, a left rear pillar 14L provided between the door panel of the left door 27L and the rear panel 32, and a right rear pillar 14R provided between the door panel of the right door 27R and the rear panel 32. Hereinafter, the door panel of the left door 27L and the door panel of the right door 27R will be collectively referred to as the door panel 27.

[0118] Fig. 16A shows a left side view of the left rear pillar 14L, and Fig. 16B shows a right side view of the right rear pillar 14R. As can be seen by comparing Fig. 16A and Fig. 16B, the left rear pillar 14L and the right rear pillar 14R are formed symmetrically with respect to a reference plane S (see Fig. 5) that passes through the center of the cabin 1 in the width direction and is perpendicular to the width direction.

[0119] 16A and 16B , the left rear pillar 14L and the right rear pillar 14R are formed into a cylindrical shape that is long in the vertical direction. The left rear pillar 14L and the right rear pillar 14R are formed into an arc shape such that the center in the vertical direction protrudes toward the outside of the vehicle (rearward and outward in the width direction) compared to the upper and lower ends.

[0120] A speaker stay 86 is provided on the inner peripheral surface of the upper portion of the left rear pillar 14L and the right rear pillar 14R. A speaker that issues audio notifications or announcements to the inside of the driver's seat 6 can be attached to the speaker stay 86.

[0121] Hinge fixing stays 81L are provided at the upper and lower ends of the left rear pillar 14L facing the exterior of the vehicle, and hinge fixing stays 81R are provided at the upper and lower ends of the right rear pillar 14R.

[0122] 1, 3, and 22, a first door hinge 29L of the left door 27L is disposed below a hinge fixing stay 81L provided at the upper end of the left rear pillar 14L, and a second door hinge 30L of the left door 27L is disposed above the hinge fixing stay 81L provided at the lower end of the left rear pillar 14L. Furthermore, a first door hinge 29R of the right door 27R is disposed below a hinge fixing stay 81R provided at the upper end of the right rear pillar 14R, and a second door hinge 30R of the right door 27R is disposed above the hinge fixing stay 81R provided at the lower end of the right rear pillar 14R. The first door hinge 29L and second door hinge 30L of the left door 27L are joined to the hinge fixing stay 81L of the left rear pillar 14L by means of welding or the like. The first door hinge 29R and the second door hinge 30R of the right door 27R are joined by welding or other means to a hinge fixing stay 81R of the right rear pillar 14R.

[0123] The left rear pillar 14L and the right rear pillar 14R are formed from the same elongated rear pillar material 34R, which has a curved shape that bulges outward toward the rear. In other words, the original material common to the left rear pillar 14L and the right rear pillar 14R is the elongated rear pillar material 34R. The elongated rear pillar material 34R is curved with the same curvature throughout its entire area from top to bottom, and the curvatures of the upper and lower halves are symmetrical vertically across the midpoint in the vertical direction. In other words, the elongated rear pillar material 34R has the same shape as the elongated front pillar material 34F. Therefore, a detailed description of the elongated rear pillar material 34R will be omitted.

[0124] The rear pillar elongated member 34R is curved so as to bulge outward toward the rear throughout its entire region from its top to its bottom, and the curvatures of its upper and lower halves are symmetrical across the vertical midpoint. Specifically, the rear pillar elongated member 34R of this embodiment has the same curvature throughout its entire region from its top to its bottom, and the curvatures of its upper and lower halves are symmetrical across the inversion reference line M, which passes horizontally midway between the top and bottom ends (the middle between the top and bottom).

[0125] Therefore, the procedure for processing the left rear pillar 14L and the right rear pillar 14R from the elongated rear pillar material 34R is the same as the procedure for processing the left front pillar 13L and the right front pillar 13R from the elongated front pillar material 34F and the procedure for processing the left side beam 18L and the right side beam 18R from the elongated side beam material 34S. In other words, before cutting the longitudinal ends of the elongated rear pillar material 34R, it is necessary to select whether or not to invert the elongated rear pillar material 34R. After cutting the longitudinal ends, it becomes possible to process the left rear pillar 14L from the elongated rear pillar material 34R that is not inverted, and the right rear pillar 14R from the inverted rear pillar material 34R. The procedure for processing the left rear pillar 14L and the right rear pillar 14R from the elongated rear pillar material 34R is substantially the same as that for the elongated front pillar material 34F, and therefore will not be described in detail.

[0126] When the above-described long material is used as a frame material that contacts the panel end of any of the front panel 31, rear panel 32, or door panel 27, it is preferable that the long material be provided with a weatherstripping (door seal 46) (see FIG. 17) for waterproofing and dustproofing. In particular, it is preferable that the door seal 46 be provided on the frame material that contacts the panel end of the door panel 27, which opens and closes as the operator OP gets in and out of the vehicle. Examples of frame materials on which the door seal 46 is desirably provided include the left front pillar 13L, the right front pillar 13R, the left side beam 18L, and the right side beam 18R. Hereinafter, the door seal 46 of this embodiment will be described using the door seal 46 provided on the panel end (front end) of the door panel 27 as a representative example.

[0127] The door seal 46 provided on the elongated material in this embodiment seals the panel ends of the left door 27L and the right door 27R. Hereinafter, the door seal 46 of this embodiment will be described using the left door seal 46L that seals the panel end of the left door 27L as a representative example.

[0128] As shown in Figure 17, the left door seal 46L is a double seal type that seals two surfaces, the inner surface and the end surface of the panel end of the left door 27L, and by sealing multiple surfaces, it exhibits high sealing performance.

[0129] Specifically, the left door seal 46L has a main lip 47 that seals a main seal surface 54 of the elongated material and a sub-lip 48 that seals a sub-seal surface 55 of the elongated material. In this embodiment, the main seal surface 54 is a portion that faces the inner surface of the front end of the left door 27L. The sub-seal surface 55 is a portion that faces the end face of the front end of the left door 27L.

[0130] With the double-lip door seal 46 described above, water (rain), wind, dust, and sound attempting to enter the cabin 1 must pass through both the contact area between the main lip 47 and the main seal surface 54 and the contact area between the sub-lip 48 and the sub-seal surface 55. This makes it more difficult for water (rain), wind, dust, and sound to reach the cabin 1 than with a single-lip seal member. Therefore, the double-lip door seal 46 more reliably prevents water (rain), wind, dust, and sound from entering the cabin 1. Furthermore, the double-lip door seal 46 can form a space (passage) between the main lip 47 and the sub-lip 48 to guide water (rain), dust, and the like that has entered through the sub-lip 48. This space (passage) is disposed along the outer periphery of the left door 27L and the right door 27R, allowing water (rain), dust, and the like to be guided downward. This further prevents water (rain), wind, dust, and the like from passing through the main lip 47 and entering the cabin 1.

[0131] In the case of the cabin 1 of this embodiment, the left door 27L and the right door 27R are configured so that their front ends rotate horizontally around their rear ends, and therefore no double-lip door seals 46 are provided between the inner surfaces of the rear ends of the left door 27L and the right door 27R and the rear pillar 14. However, instead of the single-lip seal member, a double-lip door seal 46 may be provided between the inner surfaces of the rear ends of the left door 27L and the right door 27R and the rear pillar 14.

[0132] In the above-described example, the left side surface of the left front pillar 13L and the right side surface of the right front pillar 13R are formed with a step, and the step is used to provide a double-lip door seal 46. Specifically, in the case of a step formed on the left side surface of the left front pillar 13L, a step recessed inward in the width direction is formed at the rear end of the left side surface (a step formed by the third standing wall portion 66 and the second connecting wall 62, described below). By forming such a step, the left side surface of the left front pillar 13L is formed with a surface facing outward in the width direction and a surface facing rearward. The surface facing outward in the width direction can be a main seal surface 54 against which the main lip 47 of the door seal 46 abuts, and the surface facing rearward can be a sub-seal surface 55 against which the sub-lip 48 of the door seal 46 abuts. In other words, by forming a step extending widthwise inward at the rear end of the left side surface of the left front pillar 13L, it is possible to easily form a main seal surface 54 and a sub seal surface 55 that correspond to the double lip of the weatherstrip, thereby achieving high sealing performance for the left door 27L.

[0133] Alternatively, a double-lip door seal 46 may be provided by forming a step in a component other than the left front pillar 13L or the right front pillar 13R. For example, a double-lip door seal 46 may be provided by forming a step in the side of the side beam 18. That is, as shown in FIG. 14 , a step recessed inward in the width direction is formed at the lower end of the left side surface of the left side beam 18L. By forming such a step, the left side surface of the left side beam 18L has a surface facing outward in the width direction and a surface facing downward. The surface facing outward in the width direction can be a main seal surface 54 against which the main lip 47 of the door seal 46 abuts, and the surface facing downward can be a sub-seal surface 55 against which the sub-lip 48 of the door seal 46 abuts. Therefore, by forming a step extending inward in the width direction at the lower end of the left side surface of the left side beam 18L, it is possible to easily form the main seal surface 54 and the sub-seal surface 55 corresponding to the double lips of the weatherstrip, thereby achieving high sealing performance for the left door 27L.

[0134] Furthermore, in this embodiment, the door seals 46 are provided on the front and top edges of the left door 27L and the right door 27R. However, for panels that are movable when opened and closed, door seals 46 may be provided as appropriate on panels other than the door panel 27. For example, if the rear panel 32 is attached so as to be able to open and close, a step may be formed on the front edge of the rear panel 32, and the formed step may be used to provide a double-lip door seal 46.

[0135] Next, the irregular cross section of the front pillar 13 used as a frame material of the cabin 1 of this embodiment will be described.

[0136] As described above, the term "irregular cross section" in this specification refers to a shape such that, even when the cross section is inverted about any line or rotated around any point, the shape before inversion or rotation will not be the same as the shape after inversion or rotation, in other words, a shape that does not have any linear symmetry or rotational symmetry.

[0137] In addition, in this specification, a frame material having an "irregular cross section" is referred to as an "irregular pipe." The irregular pipe of the present invention is a long material used as a frame material constituting the cabin 1 of a work machine (such as a tractor 2). While the irregular pipe in the illustration is used for the front pillar 13 of the cabin 1, the use of the irregular pipe of the present invention is not limited to the front pillar 13, nor is it limited to the cabin 1. For example, the irregular pipe of the present invention can be applied to components other than the cabin 1 of a work machine, or to components of equipment such as construction machinery used in industrial fields other than the tractor 2.

[0138] The irregular cross section of the front pillar 13 will be described below.

[0139] When the irregular cross section of the left front pillar 13L shown in Fig. 9A is flipped left to right with respect to a vertical reference plane S that passes through the center of the cabin 1 in the width direction and is perpendicular to the width direction (a vertical reference plane S that passes through the center of the cabin 1 in the width direction and is perpendicular to the width direction, see Figs. 4 to 6), it becomes congruent with the irregular cross section of the right front pillar 13R shown in Fig. 9B. Furthermore, when the irregular cross section of the right front pillar 13R shown in Fig. 9B is flipped left to right with respect to the symmetry reference plane MS, it also becomes congruent with the irregular cross section of the left front pillar 13L shown in Fig. 9A. In other words, the left front pillar 13L and the right front pillar 13R are line-symmetrical left to right.

[0140] In the following, the irregular cross section of the present invention will be described in detail using the left front pillar 13L as a representative example, taking into consideration that the shapes and structures are essentially congruent except for the point that they are line-symmetrical with respect to the symmetry reference plane MS.

[0141] 18 , the irregular cross section of the left front pillar 13L has a central cavity 59 that is continuously surrounded by multiple walls, sealing off the central cavity 59. The multiple walls surrounding the cavity 59 of the left front pillar 13L include four walls: a first wall 60, a second wall 63, a first connecting wall 61, and a second connecting wall 62.

[0142] The first wall portion 60 constitutes part of the outer periphery of the irregular-shaped pipe. Specifically, in the case of the left front pillar 13L, the first wall portion 60 is located to the front and left of the center Cp of the cavity 59 (the center of the cavity 59 in this embodiment refers to the geometric center or center of gravity of the irregular cross section in mathematics; the same applies below), and is a wall portion that corresponds to a wide range from the front and right of the center Cp to the rear and left of the center Cp. The first wall portion 60 of the left front pillar 13L is formed in a fan shape that bulges outward to the left.

[0143] The second wall portion 63 constitutes a part of the outer periphery of the irregular-shaped pipe (a part different from the first wall portion 60). The second wall portion 63 is disposed opposite the first wall portion 60 across the cavity 59. In the case of the left front pillar 13L, the second wall portion 63 is formed as a wall portion that bulges out so as to protrude rearward and inward when viewed from the center Cp of the cavity 59.

[0144] The first connecting wall 61 connects one widthwise end of the first wall portion 60 to one widthwise end of the second wall portion 63. In the case of the left front pillar 13L, the first connecting wall 61 connects the right end of the first wall portion 60 to the right end of the second wall portion 63. The first connecting wall 61 is formed to protrude outward from the pipe. In the case of the left front pillar 13L, the first connecting wall 61 is formed to protrude rightward as viewed from the center Cp of the cavity 59. The first connecting wall 61 is formed so that the inner peripheries thereof are in close contact with each other. In the example shown in FIG. 18 , the first connecting wall 61 is formed by folding a single pipe wall and bringing the inner peripheries of one and the other of the folded portion into close contact with each other. However, two pipe walls may be overlapped and the inner peripheries of the respective pipe walls may be joined by welding or the like to be in close contact with each other.

[0145] The second connecting wall 62 connects the other widthwise end of the first wall portion 60 to the other widthwise end of the second wall portion 63. In the case of the left front pillar 13L, the second connecting wall 62 connects the left end of the first wall portion 60 to the left end of the second wall portion 63. The second connecting wall 62 is formed to protrude outward from the pipe. In the case of the left front pillar 13L, the second connecting wall 62 is formed to protrude rearward when viewed from the center Cp of the cavity 59. Like the first connecting wall 61, the second connecting wall 62 is formed so that its inner periphery is tightly fitted. In other words, like the first connecting wall 61, the second connecting wall 62 is formed by folding a single pipe wall and fitting the inner periphery surfaces of one and the other of the folded portion tightly together. However, two pipe walls may be overlapped and their inner periphery surfaces may be joined by welding or the like to fit together.

[0146] Next, each wall portion that constitutes the irregular cross section of the left front pillar 13L will be described in detail.

[0147] 18 , when the center Cp of the cavity 59 is used as a reference, the first wall portion 60 is a portion that bulges outward in a fan shape when viewed from the center Cp of the cavity 59. Note that the term "fan shape" refers to a figure that is formed by two line segments that extend substantially radially from the center Cp of the cavity 59 and an arc-shaped line segment that connects the two line segments.

[0148] Specifically, the first wall portion 60 is configured by combining three standing wall portions. The three standing wall portions include a first standing wall portion 64, a second standing wall portion 65, and a third standing wall portion 66.

[0149] The first standing wall portion 64 extends from P3 toward P2, which is located forward of the center Cp, along an arc-shaped path centered at Cp. In the case of the left front pillar 13L shown in FIG. 18 , position P2 is located to the right front of the center Cp and indicates the front end (right end) of the first standing wall portion 64. Position P3 is located to the left of the center Cp and indicates the rear end (left end) of the first standing wall portion 64. In other words, the first standing wall portion 64 covers an area extending from the front right of the center Cp to the left. The second standing wall portion 65 is connected to the front end (one end) of the first standing wall portion 64, and the third standing wall portion 66 is connected to the rear end (other end) of the first standing wall portion 64.

[0150] As shown in Fig. 18 , the second standing wall portion 65 is bent inwardly of the pipe from one widthwise end of the first standing wall portion 64. Specifically, the second standing wall portion 65 is oriented so as to bend at a substantially right angle to the first standing wall portion 64 at P2 in Fig. 18 , and extends linearly from the front end of the first standing wall portion 64 located at P2 toward the inside of the cavity 59. That is, position P2 in Fig. 18 is the front end of the second standing wall portion 65, and position P4 is the rear end of the second standing wall portion 65. The second standing wall portion 65 is connected to the first connecting wall 61 at its rear end (position P4).

[0151] As shown in Fig. 18 , the third standing wall portion 66 is bent inwardly of the pipe from the other widthwise end of the first standing wall portion 64. Specifically, the third standing wall portion 66 is oriented so as to bend at a substantially right angle to the first standing wall portion 64 at position P3 in Fig. 18 , and extends linearly from the rear end of the first standing wall portion 64 located at P3 toward the inside of the cavity 59. That is, position P3 in Fig. 18 is the front end of the third standing wall portion 66, and position P1 is the rear end of the third standing wall portion 66. The third standing wall portion 66 is connected to the second connecting wall 62 at its rear end (position P1).

[0152] The first connecting wall 61 connects one widthwise end (position P4) of the first wall portion 60 and one widthwise end (position P5) of the second wall portion 63. In the case of the left front pillar 13L, the first connecting wall 61 extends from one widthwise end of the first wall portion 60 indicated by P4 in FIG. 18 in a direction slightly forward and to the right, is folded back at a first folded portion 67 in a direction slightly rearward and to the left, and then extends to one widthwise end of the second wall portion 63 indicated by P5. In other words, the first connecting wall 61 is folded back so that the first folded portion 67 protrudes to the right. Furthermore, the inner surface of the first connecting wall 61 from the first folded portion 67 to position P4 and the inner surface of the first folded portion 67 to position P5 are in close contact with each other.

[0153] 18 , the first connecting wall 61 does not extend along the right side, but rather extends in a direction that is slightly tilted forward and to the right. By configuring the first connecting wall 61 to extend in a direction that is slightly tilted forward in this manner, it becomes easier to bring the front surface of the first connecting wall 61 into parallel surface contact with the left end of the front panel 31, which is curved in an arc shape toward the front, and the first connecting wall 61 can firmly support the left end of the front panel 31.

[0154] The second connecting wall 62 connects the other widthwise end (position P1) of the first wall portion 60 and the other widthwise end (position P6) of the second wall portion 63. In the case of the left front pillar 13L, the second connecting wall 62 extends rearward from the other widthwise end of the first wall portion 60 indicated by P1 in FIG. 18 , is folded forward at the second folded portion 68, and then extends to the other widthwise end of the second wall portion 63 indicated by P6. In other words, the second connecting wall 62 is folded back so that the second folded portion 68 protrudes rearward. Furthermore, the inner surface of the second connecting wall 62 from the second folded portion 68 to position P1 and the inner surface of the second folded portion 68 from position P6 are in close contact with each other.

[0155] 18, the second connecting wall 62 extends rearward from the right end of the third standing wall portion 66 and is disposed parallel to the inner surface of the left door 27L, thereby facilitating surface-to-surface contact with the left door 27L. By aligning the formation direction of the second connecting wall 62 with the orientation direction of the inner surface of the left door 27L in this manner, the second connecting wall 62 and the left door 27L can be sealed airtight and watertight using the door seal 46 described below.

[0156] The first wall portion 60 and the second connecting wall 62 are formed to protrude in directions perpendicular to each other. In the case of the left front pillar 13L, the first wall portion 60 supports the left end of the front panel 31, and the second connecting wall 62 supports the front end of the left door 27L. Because the front panel 31 and the left door 27L are arranged in an orthogonal direction, the first wall portion 60 and the second connecting wall 62 that support these ends are also oriented in directions perpendicular to each other.

[0157] The second wall portion 63 is disposed so as to face the first standing wall portion 64 of the first wall portion 60 with the cavity 59 therebetween. The second wall portion 63 connects the rear end of the first connecting wall 61, indicated by P5 in Fig. 18, to the right end of the second connecting wall 62, indicated by P6. The second wall portion 63 in the illustrated example connects the rear end of the first connecting wall 61 and the right end of the second connecting wall 62 in the form of a broken line that protrudes outward.

[0158] An outward bent portion 70 is formed between the rear end of the first connecting wall 61 and the right end of the second connecting wall 62. The outward bent portion 70 is located outward of points P5 and P6 as viewed from the center Cp of the cavity 59. In other words, in the second wall portion 63 of the second embodiment, the outward bent portion 70 is formed so as to protrude outward from the cavity 59 as viewed from the center Cp of the cavity 59.

[0159] The second wall portion 63 between the outer bent portion 70 and P5 is formed linearly, and the second wall portion 63 between the outer bent portion 70 and P6 is also formed linearly. Furthermore, with respect to the outer bent portion 70 as the base, one second wall portion 63 and the other second wall portion 63 are formed at different inclinations.

[0160] In this embodiment, an example is given in which the first connecting wall 61 and the second connecting wall 62 are connected by folding back a single plate material, but the first connecting wall 61 and the second connecting wall 62 may also be made of two plate materials that are molded separately and joined together so that their inner surfaces are in close contact with each other.

[0161] In the second wall portion 63 of the second embodiment, the outwardly bent portion 70 is a peak 71 that protrudes outward from the cavity 59 as viewed from the center Cp of the cavity 59, relative to the rear end (P5) of the first connecting wall 61 and the right end (P6) of the second connecting wall 62. In other words, the outwardly bent portion 70 is the "peak 71 that protrudes most outward from the tube." Furthermore, the rear end (P5) of the first connecting wall 61 and the right end (P6) of the second connecting wall 62 are valleys 72 that are recessed inward into the cavity 59 as viewed from the center Cp of the cavity 59, relative to the outwardly bent portion 70. In other words, P5 is the "point of contact between the first connecting wall 61 and the second wall portion 63," and P6 is the "point of contact between the second connecting wall 62 and the second wall portion 63," and "valleys 72 recessed inward into the tube more than the peak 71" are formed at P5 and P6.

[0162] By providing such ridges 71 and valleys 72 on the second wall portion 63, when multiple pipes such as electrical wiring, drain hoses, and refrigerant pipes are arranged outside the left front pillar 13L, the pipes are naturally arranged apart from each other at the ridges 71 (see pipes H1 and H3), making it possible to prevent problems such as the pipes becoming entangled.

[0163] The second wall 63 has a flat surface between the valley 72 and the peak 71 that extends in a direction parallel to a tangent line passing through a point on the outer surface of the first wall 60. Specifically, this "flat surface" is a straight line portion of the second wall 63 disposed between the peak 71 and the position P6, and on the first wall 60, a tangent line L T That is, the second wall portion 63 has a position P7 where the tangent line L of the arc surface of the first standing wall portion 64 is T It has a flat surface parallel to the

[0164] The tangent line L passing through the point P on the outer surface of the first wall portion 60 described above T If a flat surface is formed in a direction parallel to the tangent line L T), it becomes easier to insert bolts or the like in a direction perpendicular to the left front pillar 13L and the right front pillar 13R, making it possible to firmly attach the cover 73 or the like to the left front pillar 13L and the right front pillar 13R, and making it possible to increase the bending strength (load resistance) of the front pillar 13.

[0165] Fig. 19A is a modified cross section of this embodiment, and Fig. 19B is a cross section of a conventional example, not of this embodiment. That is, in the cross section of Fig. 19A, the inner periphery of the first connecting portion 361 is not tightly adhered, and the inner periphery of the second connecting portion 362 is not tightly adhered either.

[0166] In the cross section of a conventional irregular-shaped pipe (conventional left front pillar 313L) shown in Figure 19B, it can be seen that the second wall portion 363 has an outward bent portion 370 that protrudes outward from the pipe when viewed from the center Cp' of the cavity. However, in the conventional cross section, because the second wall portion 363 protrudes outward significantly, the protruding second wall portion 363 gets in the way, making it difficult to secure sufficient space for arranging piping (see Figure 18). As a result, in the conventional cross section, it was sometimes impossible to arrange piping such as electrical wiring, drain hoses, and refrigerant piping at the rear.

[0167] Furthermore, if the pipes H1 to H3 were forcibly arranged behind the protruding second wall portion 163 in a conventional cross section, a cover (not shown) concealing the pipes H1 to H3 would also need to protrude significantly rearward. This would increase the width of the left front pillar 113L in the front-to-rear and left-to-right directions (widthwise) by the amount of the cover protruding rearward (inward). In other words, in a conventional cabin in which the left front pillar 113L is wider in the front-to-rear direction, the width of the cabin's entry / exit opening is narrowed by the amount of the widening of the left front pillar 113L, making it difficult to get in and out of the cabin. Furthermore, in a conventional cabin in which the left front pillar 113L is wider in the left-to-right direction, the field of view from the front panel is narrowed by the amount of the widening of the left front pillar 113L, which likely reduces forward visibility from the cabin.

[0168] 19A, the outward (rearward) protrusion of the second wall portion 63 is suppressed, so that sufficient space can be secured outside the second wall portion 63 to arrange the pipes H1 to H3. Furthermore, even when these pipes H1 to H3 are arranged and then concealed by the cover 73, the outward protrusion of the cover 73 can be suppressed.

[0169] As shown in FIG. 18 , the cover 73 is a plate-shaped member that covers the second wall portion 63 from the outside. By being positioned outward of the outward bend 70 (mountain portion 71), a space can be secured between the cover 73 and the second wall portion 63 to accommodate the pipes H1 to H3. Specifically, the cover 73 includes a first cover wall 73a extending rearward from the end of the first connecting wall 61 that protrudes outward from the pipes, a second cover wall 73b extending inward in the width direction from the end of the second connecting wall 62 that protrudes outward from the pipes, and a third cover wall 73c connecting the first cover wall 73a and the second cover wall 73b. The first cover wall 73a is positioned outward in the width direction from a forward visibility boundary line FL that connects the center of the driver's seat 6 and the end of the first connecting wall 61 that protrudes outward from the pipes. Furthermore, the second cover wall 73b is located forward of the side visibility boundary line SL connecting the center of the driver's seat 6 and the second folded portion 68. Therefore, even if the cover 73 is provided, the first cover wall 73a of the cover 73 does not protrude so as to obstruct the forward visibility. Furthermore, the second cover wall 73b of the cover 73 does not protrude so as to obstruct the left entrance / exit door 28L and narrow the opening width of the left entrance / exit door 28L of the cabin 1. In other words, the cover 73 does not narrow the opening width of the entrance / exit door of the cabin 1 or the field of view of the front panel 31. Therefore, the width of the left front pillar 13L in the fore-and-aft direction and the width in the lateral direction as seen from the driver's seat 6 can be maintained wide, improving the ease of getting in and out of the cabin 1 and the visibility.

[0170] In addition to the examples shown in Figures 18 and 19A, examples of the irregular cross section in which "the second wall portion 63 is recessed toward the cavity 59" include the examples shown in Figures 20A and 20B.

[0171] The irregular cross section shown in Fig. 20A shows an example in which the contact area on the inner periphery of the first connecting wall 61 is wider than the irregular cross section of the present embodiment shown in Fig. 19A. Compared to the irregular cross section shown in Fig. 18, the space that can be secured behind the second wall portion 63 is larger, but the bending strength of the front pillar 13 is slightly lower due to the smaller cross-sectional area of ​​the irregular cross section.

[0172] The irregular cross-section shown in FIG. 20B is an example in which the first connecting wall 61 and the second connecting wall 62 are formed by stacking two separate plate materials (an example in which the inner peripheries of the two plate materials are in close contact). That is, the irregular pipes shown in FIGS. 20A and 20B are formed from two plate materials. Specifically, the irregular pipe shown in FIG. 20A is formed by joining, by welding or the like, one plate material constituting the first wall portion 60, a portion of the first connecting wall 61, and a portion of the second connecting wall 62, and another plate material constituting the second wall portion 63, the remaining portion of the first connecting wall 61, and the remaining portion of the second connecting wall 62. The irregular cross-section shown in FIG. 20B also maintains the bending strength of the front pillar 13 while ensuring space for arranging the pipes H1 to H3 and improving the ease of entry and exit and visibility of the cabin 1.

[0173] The irregular pipe having the irregular cross section described above can be used for various types of frame materials, not just the front pillar 13. The configuration of the irregular pipe is the same as the configuration of the left front pillar 13L having the irregular cross section described above, so a description thereof will be omitted.

[0174] In the cabin 1 of this embodiment, in preparation for the case where a large load is applied to the front pillars 13, measures such as using frame materials with irregular cross sections as described above for the front pillars 13 are taken to increase the load-bearing capacity of the front pillars 13. However, when considering safety in the event of the work equipment tipping over, it is preferable not only to have the load applied to the cabin 1 supported only by the front pillars 13, but also to reinforce the side beams 18 connected to the front pillars 13, thereby improving the load-bearing capacity of the entire cabin 1. Therefore, in the cabin 1 of this embodiment, reinforcing members 49 are provided on the upper parts of the rear pillars 14.

[0175] Next, the reinforcing member 49 provided in the cabin 1 of this embodiment will be described.

[0176] As shown in Figures 7, 21, and 22, a reinforcing member 49 provided at the upper part of the rear pillar 14 passes through the interior side of the rear pillar 14 and connects the rear beam (rear beam 16) and the side beam 18 in a diagonal brace manner. The reinforcing member 49 is a plate member bent in a generally L-shape when viewed from above. The front end of the reinforcing member 49 is fixed to the side beam 18, the rear end (the tip extending inward in the width direction) to the rear beam 16, and the central portion in the fore-and-aft direction to the upper part of the rear pillar 14, each fixed by means of welding or the like. In other words, the reinforcing member 49 connects the rear beam 16, the upper part of the rear pillar 14, and the side beam 18, thereby supporting the side beam 18 against the rear beam 16 and the upper part of the rear pillar 14.

[0177] The reinforcing member 49 of this embodiment includes a left reinforcing member 49L provided on the upper part of the left rear pillar 14L and a right reinforcing member 49R provided on the upper part of the right rear pillar 14R. The left reinforcing member 49L and the right reinforcing member 49R have a symmetrical structure and are basically the same except for the symmetry. Therefore, hereinafter, the reinforcing member 49 of the present invention will be described using the right reinforcing member 49R provided on the upper part of the right rear pillar 14R as an example.

[0178] First, the rear beam 16 to which the right reinforcing member 49R is connected will be described in detail.

[0179] 2 and 6, the rear beam 16 is a frame member that connects the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R to the left and right. Unlike the front beam 15, the rear beam 16 is not curved upward, but is formed so as to extend linearly in the left-right direction.

[0180] As shown in FIG. 7 , the rear beam 16 is a frame material with a generally U-shaped cross section that opens forward (a square with top, bottom, front, and rear sides, with the front side removed and the top, rear, and bottom sides remaining, forming an angular U-shape). A left second fixed plate 83L is provided on the left side of the rear beam 16, connecting the opening that opens forward in the vertical direction. A right second fixed plate 83R is provided on the right side of the rear beam 16, connecting the opening in the vertical direction. The distance from the left end of the rear beam 16 to the left second fixed plate 83L is equal to the distance from the right end of the rear beam 16 to the right second fixed plate 83R. The upper and lower edges of the left second fixed plate 83L and the right second fixed plate 83R are joined to the opening of the rear beam 16 by welding or other means.

[0181] As shown in FIGS. 13A to 13C , the first fixing plate 42 is provided to fix the front end of the reinforcing member 49 by welding. Specifically, the first fixing plate 42 is a plate member that stands upright in the vertical direction and is attached to extend in the front-to-rear direction. The first fixing plate 42 includes a left first fixing plate 42L that fixes the left reinforcing member 49L and a right first fixing plate 42R that fixes the right reinforcing member 49R. The upper end of the left first fixing plate 42L is joined to the right end of the upper wall portion 39 of the left side beam 18L, and the lower end of the left first fixing plate 42L is joined to the right end of the lower wall portion 44 of the left side beam 18L. Although not shown, the upper end of the right first fixing plate 42R is joined to the left end of the upper wall portion 39 of the right side beam 18R, and the lower end of the right first fixing plate 42R is joined to the left end of the lower wall portion 44 of the right side beam 18R. A front end of the left reinforcing member 49L (a left first connection portion 82L, described later) is joined to a vertically midpoint of the left first fixed plate 42L. A front end of the right reinforcing member 49R (a right first connection portion 82R, described later) is joined to a vertically midpoint of the right first fixed plate 42R. Joining the front ends of the left reinforcing member 49L and the right reinforcing member 49R to the vertically midpoint of the right first fixed plate 42R makes it less likely that spatter debris generated during welding will adhere to the upper surface of the upper wall portion 39, thereby improving the sealing performance of the door seal 46.

[0182] In this embodiment, welding is used to join the front end of the reinforcing member 49 to the first fixing plate 42, but brazing, screw fastening, adhesive, or the like may also be used.

[0183] Next, the right reinforcing member 49R will be described in detail.

[0184] The front end (front portion) of the right reinforcing member 49R is connected to the vicinity of the center of the right side beam 18R in the fore-and-aft direction, which in this embodiment is the right first fixed plate 42R. In other words, the front end of the right reinforcing member 49R serves as a right first connection portion 82R that connects the right reinforcing member 49R to the right side beam 18R. In addition, the right end (right portion) of the right reinforcing member 49R is connected to the right portion of the rear beam 16, which in this embodiment is the right second fixed plate 83R. In other words, the right end (right portion) of the right reinforcing member 49R serves as a right second connection portion 84R that connects the right reinforcing member 49R to the right portion of the rear beam 16.

[0185] The right reinforcing member 49R has a central base 85 between the right first connection portion 82R (front end) and the right second connection portion 84R (rear end). As shown in detail in FIG. 21 , the right rear edge of the central base 85 is joined to the outer peripheral surface of the right rear pillar 14R on the interior side. Specifically, the right rear edge of the central base 85 (the edge facing the exterior) is in direct contact with the outer peripheral surface of the right rear pillar 14R on the interior side, and the contact points are joined by welding. Note that the joining of the central base 85 is not limited to the direct joining described above. Specifically, a speaker stay 86 for attaching a speaker is provided on the upper part of the right rear pillar 14R. The speaker stay 86 is a box-shaped member that protrudes toward the interior side and has a speaker mounting hole 87 on its surface facing the interior side into which the speaker is fitted. The above-described central base 85 is placed on a box-shaped speaker stay 86, and the underside of the central base 85 and the upper end of the speaker stay 86 are joined by means such as welding. In other words, the right reinforcing member 49R is also joined to the outer peripheral surface of the right rear pillar 14R on the cabin side by indirect joining means via the speaker stay 86. By using these two types of joining, the right reinforcing member 49R is firmly joined to the upper part of the right rear pillar 14R.

[0186] The right first fixing plate 42R is provided near the center of the right side beam 18R in the fore-and-aft direction. This "near the center" means not only the center of the right side beam 18R in the fore-and-aft direction, but also slightly behind or in front of the center. Specifically, the "near the center" also includes a position that is approximately 20% of the total length of the right side beam 18R in the fore-and-aft direction and is located rearward or forward from the center in the fore-and-aft direction.

[0187] Furthermore, the above-described right first connection portion 82R is provided at the vertical center of the right first fixed plate 42R, and the right second connection portion 84R is provided at the vertical center of the right second fixed plate 83R. In other words, the right first connection portion 82R is located below the upper surface of the right side beam 18R, and the right second fixed plate 83R is located below the upper surface of the right portion of the rear beam 16. If the right first connection portion 82R is formed at a distance below the upper surface of the right side beam 18R in this manner, spatter debris generated when joining the right first connection portion 82R to the right first fixed plate 42R by welding or the like is less likely to fly onto the upper surface of the right side beam 18R, which is the sealing surface, by the distance in the vertical direction. Furthermore, if the right second connection portion 84R is formed at a distance downward from the upper surface of the right part of the rear beam 16, spatter debris generated when joining the right second connection portion 84R to the right second fixing plate 83R by welding or the like is less likely to fly onto the upper surface of the rear beam 16, which is the sealing surface, by the amount of the distance in the vertical direction. As a result, it is possible to improve the sealing performance between the roof 9 and the cabin 1.

[0188] The right reinforcing member 49R is formed to be longer in the front-rear direction than in the width direction (left-right direction). Specifically, in Figure 21, if the distance between the right first connection portion 82R and the central base portion 85 is L1 and the distance between the right second connection portion 84R and the central base portion 85 is L2, the relationship distance L1 > distance L2 holds.

[0189] To be precise, the distance L1 refers to the length along the front-rear direction of a line connecting the center of the joint portion of the right first connection portion 82R to the right first fixed plate 42R and the front end of the central base 85. The distance L2 refers to the length along the left-right direction of a line connecting the center of the joint portion of the right second connection portion 84R to the right second fixed plate 83R and the right end of the central base 85.

[0190] If the distance L1 is made greater than the distance L2, the right first connection portion 82R of the right reinforcing member 49R can support a more forward portion of the right side beam 18R, thereby increasing the deformation resistance at the front portion of the cabin 1 (deformation resistance when the cabin 1 is deformed in the left-right direction). In other words, by providing the right reinforcing member 49R with a shape such that the distance L1 is greater than the distance L2, the cabin 1 of the present embodiment can increase not only the strength of the rear portion of the cabin frame 8 but also the strength of the front portion. As a result, the cabin 1 of the present embodiment can suppress deformation and damage to the cabin 1 even in the event of a rollover, and can further improve safety compared to conventional cabins.

[0191] Next, the roof seal 45 will be described in detail.

[0192] The roof seal 45 is a member that seals between the roof 9 and the upper surfaces of the four frame members provided at the top of the cabin 1, namely the front beam 15, the left side beam 18L, the right side beam 18R, and the rear beam 16.

[0193] 7 , the roof seal 45 is disposed continuously around the driver's seat 6 on the upper surfaces of the front beam 15, the left side beam 18L, the right side beam 18R, and the rear beam 16. When the roof seal 45 passes over a reinforcing member 49 provided on the upper portion of the rear pillar 14, the roof seal 45 is disposed so as to pass on the interior side of the rear pillar 14.

[0194] FIG. 21 shows an enlarged view of the roof seal 45 (the portion indicated by A in FIG. 7) passing over the reinforcing member 49.

[0195] 21 , a roof seal surface 88 on which the roof seal 45 is disposed is formed on the upper surface of the right reinforcing member 49R. The roof seal surface 88 includes a first seal surface 89, a second seal surface 90, and a third seal surface 91.

[0196] In addition, the black dots in the drawings indicate the area indicated by the reference numerals, including the area around the black dots. For example, the black dot indicated by the reference numeral 89 indicates that the area including the area around the black dots is the first sealing surface 89.

[0197] The first sealing surface 89 is a portion of the upper surface of the right reinforcing member 49R that is adjacent to the upper surface 18Re of the rear portion of the right side beam 18R (on the interior side). The first sealing surface 89 is formed at the same height as the upper surface 18Re of the rear portion of the right side beam 18R and is substantially flush with the upper surface 18Re. Therefore, the roof seal 45, which is disposed rearward along the upper surface of the right side beam 18R, can be guided (positioned) from the upper surface 18Re to the first sealing surface 89 without changing its height.

[0198] The second sealing surface 90 is a portion of the upper surface of the right reinforcing member 49R that is adjacent to the front of the upper surface 16Re of the right portion of the rear beam 16. The second sealing surface 90 is formed at approximately the same height as the upper surface 16Re of the right portion of the rear beam 16, and is substantially flush with the upper surface 16Re. Therefore, the roof seal 45, which is disposed rightward along the upper surface 16Re of the rear beam 16, can be guided (positioned) from the upper surface 16Re to the second sealing surface 90 without changing its height.

[0199] The third seal surface 91 is formed between the first seal surface 89 and the second seal surface 90 and also forms the upper surface of the central base 85. The third seal surface 91 does not have to be at the same height as the first seal surface 89 or the second seal surface 90. In this embodiment, the third seal surface 91 is also disposed at a position slightly lower than the first seal surface 89 or the second seal surface 90. However, the third seal surface 91 must be continuous with the first seal surface 89 and the second seal surface 90. Therefore, a gentle slope connecting two surfaces of different heights is formed between the third seal surface 91 and the first seal surface 89 or between the third seal surface 91 and the second seal surface 90 in this embodiment. Forming the third seal surface 91 as a surface continuous with the first seal surface 89 and the second seal surface 90 allows the roof seal 45 to be guided (positioned) from the first seal surface 89 to the second seal surface 90 without a sudden change in height.

[0200] In other words, if the roof seal surface 88, including the first seal surface 89, the second seal surface 90, and the third seal surface 91, is formed on the upper surface of the right reinforcing member 49R, there will be no step on the sealing surface on which the roof seal 45 is placed. Therefore, the roof seal 45 can be positioned to pass through the cabin interior of the rear pillar 14 without abrupt changes in height. In other words, the roof seal 45, which is made of an elastic material, can seal by deforming itself even if there is a slight step in the vertical direction. However, if the step becomes large, the roof seal 45 will no longer be able to cover the step by deforming itself, making it difficult to provide a sufficient seal. In particular, some conventional cabins have a rear beam that is lower than the right side beam 18R. In such conventional cabins, the sealing material may be interrupted around the rear beam, resulting in insufficient sealing. However, in the cabin 1 of this embodiment, which uses the right reinforcing member 49R with the roof seal surface 88, the roof seal 45 can be positioned without interruption, thereby providing sufficient sealing.

[0201] The above-mentioned reinforcing member 49 is provided on the upper part of the rear pillar 14 and connects the end of the rear beam 16 to the rear end of the side beam 18, thereby increasing the load-bearing capacity of the cabin 1. However, in the cabin 1 of this embodiment, in addition to the reinforcing member 49 on the upper part of the rear pillar 14, front reinforcing means for increasing the load-bearing capacity of the cabin 1 is also provided on the upper part of the front pillar 13. Two front reinforcing means are provided, one on the upper part of the left front pillar 13L and one on the upper part of the right front pillar 13R.

[0202] Hereinafter, the front reinforcing means of this embodiment will be described using the front reinforcing means provided on the upper part of the right front pillar 13R as an example.

[0203] As shown in FIG. 23 , the front reinforcement means provided on the upper portion of the right front pillar 13R includes a right first welding auxiliary portion 50R provided in front of the right side beam 18R and a right second welding auxiliary portion 51R provided at the right end of the front beam 15. The right first welding auxiliary portion 50R is a plate member extending inwardly rearward from the front end of the right side beam 18R. The right first welding auxiliary portion 50R is joined to the lower surface of the upper wall portion 39 of the right side beam 18R, the upper surface of the lower wall portion 44, and the inner surface of the side wall portion by means of welding or other means. The right second welding auxiliary portion 51R is a plate member bent into a substantially L-shape when viewed from above and joined to the right end of the lower wall portion 15b of the front beam 15. The right end of the right second welding auxiliary portion 51R is oriented substantially perpendicular to the right first welding auxiliary portion 50R, allowing a T-joint to be welded to the surface of the right first welding auxiliary portion 50R.

[0204] If the right first welding auxiliary portion 50R and the right end of the right second welding auxiliary portion 51R can be joined by T-joint welding, the area of ​​the welded portion will be larger than with normal butt welding, and it will be possible to firmly join the front portion of the right side beam 18R and the right end of the front beam 15.

[0205] Next, a support structure 99 for the front panel 31 provided in the cabin 1 of this embodiment will be described.

[0206] Figure 24 is an enlarged rear view of the support structure 99 as seen from the rear (driver's seat 6). Since the brake pedal 97, steering column 121, and interlock release pedal 124 obstruct the view of the front structure of the support structure 99 in Figure 24, Figure 25 also shows an enlarged rear view of the support structure with the brake pedal, steering column, and interlock release pedal removed. Figure 26 is an enlarged front view of the support structure as seen from the front. Furthermore, Figure 27 is a cross-sectional view of the support structure 99 cut along the front-rear direction midway in the left-right direction.

[0207] 24 to 27, the cabin 1 of this embodiment includes a front panel 31 and a support structure 99 for the front panel 31 in front of the driver's seat 6. The support structure 99 supports the front panel 31 separately from the left front pillar 13L and the right front pillar 13R disposed outward in the width direction, and supports the front panel 31 from below.

[0208] 25 and 26, the front panel 31 of this embodiment is formed as a single plate with a cutout 100 at the center of the width direction of the lower end. The cutout 100 of this embodiment is formed as a rectangular recess extending upward at the center of the width direction of the front panel 31.

[0209] 24 and 25 , the support structure 99 includes a panel support frame 95 to which the front panel 31 is attached. The panel support frame 95 is formed to protrude upward from the step 23 in front of the driver's seat 6. The panel support frame 95 includes an opening frame 102 that stands upright in the vertical direction along the front panel 31, and a base frame 103 that is connected to the rear of the periphery of the opening frame 102. The support structure 99 includes a pedal support portion 98 that supports a brake pedal 97 on the panel support frame 95. The pedal support portion 98 of this embodiment includes a support shaft 101 that supports the brake pedal 97 so that it can swing.

[0210] Next, the panel support frame 95 and the pedal support portion 98 that constitute the support structure 99 will be described.

[0211] First, the front panel 31 supported by the support structure 99 will be described.

[0212] 5 and 25, the front panel 31 is formed from a light-transmitting panel, and its upper, left, and right ends are fixed to the front beam 15, the left front pillar 13L, and the right front pillar 13R. The front panel 31 is formed in a curved shape that bulges forward. A notch 100 is formed in the lower end of the front panel 31 at the center in the width direction.

[0213] The cutout portion 100 is a rectangular cutout formed in the lower edge of the center in the width direction of the front panel 31. The cutout portion 100 is formed in a horizontally elongated rectangular shape when viewed from the front, and opens downward.

[0214] The panel support frame 95 is disposed behind the cutout portion 100 and is a member to which the front panel 31 can be attached. The panel support frame 95 has an opening frame 102 that stands upright in the vertical direction along the front panel 31, and a base frame 103 that is connected to the rear of the periphery of the opening frame 102.

[0215] The opening frame 102 is an upright plate member and is formed in a gate shape (like the upper half of a substantially square frame divided into two equal parts, top and bottom) to fit the opening shape of the cutout portion 100 in the front panel 31. In other words, the opening frame 102 has a horizontally elongated rectangular opening when viewed from the front, corresponding to the opening shape of the cutout portion 100. The opening of the opening frame 102 is surrounded on three sides, excluding the bottom, by a left opening edge 102a, a right opening edge 102b, and an upper opening edge 102c. The opening frame 102 has a predetermined thickness extending outward from the left opening edge 102a, the right opening edge 102b, and the upper opening edge 102c, and is configured as a single continuous plate member that surrounds the periphery of the opening. The opening frame 102 is attached to the front panel 31 around the cutout portion 100 using adhesive or fasteners, and is capable of supporting from below the weight of the front panel 31, the roof 9, and even part of the weight of air conditioners installed inside the roof 9.

[0216] Note that the opening frame 102 supports only a portion of the weight of the front panel 31, the roof 9, and the air conditioners installed within the roof 9. In other words, in the cabin 1 of this embodiment, a left front pillar 13L and a right front pillar 13R that support the front panel 31 are provided at the left and right ends of the front panel 31, respectively. Furthermore, a front beam 15 that curves upward and protrudes upward is provided at the upper ends of the left front pillar 13L and the right front pillar 13R at the upper ends of the front panel 31. Therefore, the weight of the roof 9 installed above the driver's seat 6 and the air conditioners installed within the roof 9 is applied to the left front pillar 13L and the right front pillar 13R via the front beam 15. The weight of the front panel 31, which is made of glass or the like, is also applied to the left front pillar 13L and the right front pillar 13R. Although most of the weight is applied to the left front pillar 13L and the right front pillar 13R, part of the weight of the roof 9 and part of the weight of the front panel 31 are also applied to the opening frame 102 via the left front pillar 13L and the right front pillar 13R. In other words, part of the weight of the front panel 31, the roof 9, and the air conditioner and other components provided within the roof 9 is also supported by the front panel 31, although the weight share is smaller than that of the left front pillar 13L and the right front pillar 13R.

[0217] The base frame 103 is a frame member resembling a triangular prism laid on its side, disposed adjacent to the rear of the opening frame 102. The base frame 103 is connected to the periphery of the opening of the opening frame 102, i.e., the left opening edge 102a, the right opening edge 102b, and the top opening edge 102c.

[0218] Specifically, the base frame 103 includes a left base frame side wall 103a, a right base frame side wall 103b, and a frame plate 106, which are connected to the left opening edge 102a, the right opening edge 102b, and the upper opening edge 102c of the opening frame 102, respectively.

[0219] The left base frame side wall 103a is connected to the rear of the left opening edge 102a of the opening frame 102, and the right base frame side wall 103b is connected to the rear of the right opening edge 102b of the opening frame 102. When viewed from the side, both the left base frame side wall 103a and the right base frame side wall 103b are formed in a triangular shape such that their vertical height decreases toward the rear.

[0220] The frame plate 106 is a plate member having a rectangular shape when viewed from above, and is connected to the rear of the upper opening edge 102c of the opening frame 102. The frame plate 106 is inclined so as to transition upward from the rear toward the upper part of the opening frame 102 (so as to descend toward the rear). A left through-portion 106a and a right through-portion 106b are formed on the left and right sides of the frame plate 106, penetrating the frame plate 106 and communicating with the inside and outside of the cabin 1. The left through-portion 106a and the right through-portion 106b are closed by a left closing plate 116a and a right closing plate 116b, respectively. The right closing plate 116b, which closes the right through-portion 106b, has a through-hole 105 formed therein through which the steering shaft 104, which extends forward and downward from in front of the driver's seat 6, passes, and a bellows-type boot portion 117 is attached to the through-hole 105.

[0221] The support structure 99 not only has the function of supporting the front panel 31, but also has the function of supporting the brake pedal 97 and the clutch member 115. Specifically, the support structure 99 has a pedal support portion 98 that supports the brake pedal 97 relative to the panel support frame 95 in order to support the brake pedal 97 (and possibly the clutch member 115).

[0222] The pedal support portion 98 has a support portion main body 118 assembled in a tower-like shape above the panel support frame 95, a support frame 119 that supports the support portion main body 118 relative to the panel support frame 95, and a support shaft 101 that supports the brake pedal 97 so that it can swing.

[0223] As shown in FIG. 25 , the support frame 119 includes five frames. The five frames are a left first frame 108, a left second frame 109, a central frame 110, a right first frame 111, and a right second frame 112. The left first frame 108 supports the left end of the support shaft 101 relative to the left end of the base frame 103. The left second frame 109 supports the left end of the opening frame 102 relative to the left first frame 108. The central frame 110 supports the midpoint of the support shaft 101 in the left-right direction relative to the center of the base frame 103. The right first frame 111 supports the central frame 110 and the right end of the support shaft 101 relative to the right end of the base frame 103. The right second frame 112 supports the right end of the opening frame 102 relative to the right first frame 111. By using the support frame 119 made up of these five frames for support, it is possible to firmly support the support portion main body 118 at a position spaced above the base frame 103 (panel support frame 95).

[0224] The support body 118 is a cylindrical member arranged along the horizontal direction, and is fixed so as to span the upper ends of the left first frame 108, the center frame 110, and the right first frame 111 of the support frame 119 in the horizontal direction. The support body 118 is inserted into the inside of the cylindrical member and can be fixed so that the support shaft 101 is oriented in the horizontal direction.

[0225] A steering column 121 that rotatably supports the steering shaft 104 is attached to the right side of the support body 118. The steering column 121 is a tubular member that rises at an angle from a lower front to an upper rear. Two steering shafts 104 are provided, one above the other, with an upper steering shaft 104a and a lower steering shaft 104b connected via a universal joint so that steering motion can be transmitted. The upper steering shaft 104a passes through the interior of the steering column 121 and is rotatable relative to the steering column 121. A steering handle is attached to the upper end of the upper steering shaft 104a, so that rotation of the steering handle can be transmitted to rotation of the upper steering shaft 104a. The lower steering shaft 104b is connected to the lower end of the upper steering shaft 104a. The lower steering shaft 104b protrudes outside the cabin 1 through a through-hole 105 formed in the right closure plate 116b of the frame plate 106.

[0226] A connecting reinforcement frame 113 is provided below the support main body 118. The connecting reinforcement frame 113 is a plate member with a rectangular cross section, with the vertical midpoint protruding forward from the upper and lower ends. The connecting reinforcement frame 113 is fixed to the lower part of the support main body 118 by means of welding or the like. The connecting reinforcement frame 113 also joins three members, the left first frame 108, the center frame 110, and the right first frame 111, in a state where they are connected in the left-right direction, and by connecting and integrating these members, the support strength of the support structure 99 is increased.

[0227] The support shaft 101 is a rod member whose horizontal length is longer than that of the support body 118, and both left and right ends of the support shaft 101 protrude outward in the left-right direction from both ends of the support body 118. Specifically, the support shaft 101 has a left end 101a that protrudes leftward from the left end of the support body 118, and a right end 101b that protrudes rightward from the right end of the support body 118. A brake pedal 97 is attached to the left end 101a of the support shaft 101 so as to be rotatable about an axis facing horizontally. Although not shown, in the case of a tractor 2 (work machine) provided with a clutch, a clutch member may also be provided at the left end 101a of the support shaft 101.

[0228] In this embodiment, two brake pedals 97 are provided side by side in the left-right direction on the left end 101a of the support shaft 101. That is, the brake pedals 97 include a left brake pedal 97L provided on the left and a right brake pedal 97R provided on the right. The left brake pedal 97L is a pedal for stopping the left rear wheel 12L. The right brake pedal 97R is a brake for stopping the right rear wheel 12R. The left brake pedal 97L includes a left pedal arm 122L whose base end is rotatably supported on the support shaft 101, a left pedal plate 123L attached to the tip of the left pedal arm 122L, and a left pedal spring 125L that biases the left pedal arm 122L in a direction returning it to its initial depression position. The right brake pedal 97R also includes a right pedal arm 122R whose base end is rotatably supported on the support shaft 101, a right pedal plate 123R attached to the tip of the right pedal arm 122R, and a right pedal spring 125R that biases the right pedal arm 122R in a direction returning it to its initial depressed position.

[0229] Between the left pedal plate 123L and the right pedal plate 123R, an interlocking member 114 is provided, which connects the two members, allowing the left and right brakes to be simultaneously depressed and released. The interlocking member 114 connects the left pedal plate 123L and the right pedal plate 123R electromagnetically or hydraulically, and connecting the left pedal plate 123L and the right pedal plate 123R links the left and right brakes together. The interlocking of the interlocking member 114 is released by an interlock release pedal 124.

[0230] The interlock release pedal 124 is a pedal that releases the interlocking effected by the interlocking member 114, and is provided on either the left or right side of the support structure 99. In this embodiment, the interlock release pedal 124 is disposed approximately in the center of the support structure 99, so the five frames that make up the support frame 119 can remain straight (they do not need to be bent).

[0231] However, when the interlock release pedal 124 is disposed on the left of the support structure 99, it is preferable that the intermediate sides in the up-down direction be bent inward in the left-right direction relative to the frame on which the interlock release pedal 124 is disposed, i.e., the left first frame 108 and left second frame 109 disposed on the left of the support structure 99. On the other hand, when the interlock release pedal 124 is disposed on the right of the support structure 99, it is preferable that the intermediate sides in the up-down direction bent inward in the left-right direction relative to the right first frame 111 and right second frame 112 disposed to the right of the frame on which the interlock release pedal 124 is disposed. The example shown in Figure 24 is suitable for use when the intermediate sides in the up-down direction of the right first frame 111 and right second frame 112 are bent leftward and the interlock release pedal 124 is disposed on the right of the support structure 99.

[0232] Furthermore, even when the clutch member is arranged to the left of the support structure 99, the left frame (left first frame 108 and left second frame 109) of the pedal support portion 98 can be bent toward the right at the midpoint in the vertical direction.

[0233] With such a cabin 1, even if there are components such as an interlock release pedal 124 or a clutch member on one of the left and right sides of the support structure 99, the frame of the pedal support part 98 does not get in the way when stepping on the interlock release pedal 124 or the clutch member, and interlock release or operation of the clutch member can be performed reliably.

[0234] Incidentally, in the cabin 1 of this embodiment, the height of the opening frame 102 provided in the panel support frame 95 is reduced, and the cutout portion 100 is kept low and small in area relative to the front panel 31. By keeping the cutout portion 100 low and small in area in this way, the field of view of the front panel 31 can be widened, and visibility from the cabin 1 can be improved. Furthermore, making the cutout portion 100 smaller reduces the effort required for cutting the front panel 31 and makes it less likely to break. Furthermore, as described above, the strength of the front panel 31 formed as a single plate can be improved.

[0235] Regarding how low the cutout 100 should actually be, it is sufficient that the cutout 100 is positioned below the support shaft 101. In this case, in the cabin 1 of this embodiment, the opening frame 102 of the panel support frame 95 is positioned along the back surface of the front panel 31, but it is preferable to position the opening frame 102 so that there is no portion above the opening frame 102 that is positioned along the back surface of the front panel 31. In other words, the opening frame 102 and the front panel 31 in front of the opening frame 102 are fixed in surface contact, but the panel support frame 95 is not provided in front of the front panel 31 even slightly above the opening frame 102, so that nothing obstructs the field of view from the front panel 31. By adopting such an arrangement, visibility from the cabin 1 can be reliably improved.

[0236] Next, the positional relationship between the clutch housing 107 and the frame plate 106 will be described with reference to FIG.

[0237] FIG. 27 shows a cross-sectional view of the cabin 1 cut at the middle in the left-right direction.

[0238] As shown in FIG. 27 , the frame plate 106 of the base frame 103 is inclined upward (sloping downward toward the rear) from the rear toward the upper portion of the opening frame 102. The frame plate 106 is inclined in this manner to avoid interference with the clutch housing 107 located below the driver's seat 6. That is, the tractor 2 of this embodiment is equipped with an engine (prime mover E1) in front of the cabin 1, and a flywheel and clutch plate are disposed behind the engine. For example, a flywheel is necessarily vertically long in order to generate sufficient inertial force. Therefore, the front end of the clutch housing 107 is inclined to increase in vertical width toward the front to accommodate the flywheel and other components. To accommodate such a clutch housing 107 with a vertically wide front end, it is preferable to also incline the front end of the lower part of the cabin 1. In particular, in a tractor 2 that is prone to vibration during operation, it is necessary to provide a sufficient gap between the clutch housing 107, whose front end is inclined, and the clutch housing 107 to avoid interference with the clutch housing 107. 27, the lower steering shaft 104b connected to the lower end of the upper steering shaft 104a passes through a through-hole 105 formed in the right closure plate 116b of the frame plate 106 and protrudes outside the cabin 1. Power is transmitted to the lower end of this lower steering shaft 104b via a universal joint outside the cabin 1. Therefore, in order to accommodate the universal joint, which requires a relatively large installation space, it is necessary to provide a sufficient gap between the lower steering shaft 104b and the clutch housing 107, and therefore the front end of the cabin 1 is inclined forward and upward.

[0239] The cabin 1 of this embodiment has an inclined front end to provide a sufficient gap between it and the clutch housing 107, but by minimizing the inclination of the front end and keeping the vertical width of the cutout 100 in the front panel 31 low, it is possible to ensure a wide field of view from the front panel 31. In other words, by keeping the vertical width of the cutout 100 in the front panel 31 low, the cabin 1 of this embodiment avoids physical interference with the clutch housing 107, ensures installation space for components such as a universal joint, and improves field of view from the front panel 31.

[0240] 27 , in the cabin 1 of this embodiment, the front panel 31 is curved so that the middle portion in the up-down direction protrudes forward relative to the lower end. In other words, the middle portion in the up-down direction of the front panel 31 protrudes forward relative to the lower end. Therefore, it is preferable that the opening frame 102 be in a forward-leaning position so that the middle portion in the up-down direction protrudes forward relative to the lower end so that it can come into surface contact with the curved front panel 31.

[0241] In the cabin 1 of this embodiment, the front panel 31 is curved so that its middle portion in the left-right direction protrudes forward relative to both the left and right ends. In other words, the front panel 31 protrudes forward relative to both the left and right ends. Therefore, it is preferable that the opening frame 102 has a curved shape in which its middle portion in the left-right direction protrudes forward so that it can come into surface contact with the curved front panel 31.

[0242] Furthermore, in the cabin 1 of this embodiment, the front panel 31 is curved so that the middle of the vertical direction protrudes forward from the lower end, and it is preferable that the left front pillar 13L and the right front pillar 13R are in a forward-leaning position so that the middle of the vertical direction protrudes forward from the lower end, in accordance with the curvature of the front panel 31.

[0243] With such a cabin 1, even for a full-round type front panel 31 that curves so that the center protrudes forward, the front panel 31 can be securely fixed by tightly contacting the periphery of the cutout portion 100 of the front panel 31 with the opening frame 102 of the panel support frame 95 and by tightly contacting both ends of the front panel 31 with the left front pillar 13L and the right front pillar 13R.

[0244] The present invention provides a cabin 1 described in the following items: (Item A1) The cabin 1 includes a front panel 31 disposed in front of a driver's seat 6, a left door 27L disposed to the left of the driver's seat 6, a right door 27R disposed to the right of the driver's seat 6, a left front pillar 13L provided between the front panel 31 and the left door 27L, and a right front pillar 13R provided between the front panel 31 and the right door 27R, and the left front pillar 13L and the right front pillar 13R use elongated members (front pillar elongated members 34F) of the same shape that curve so as to bulge forward.

[0245] (Item A2) The cabin 1 described in Item A1, in which the left front pillar 13L and the right front pillar 13R are made of frame material in which the longitudinal ends of a long material (front pillar long material 34F) have been cut off and the parts other than the longitudinal ends have the same shape.

[0246] (Item A3) A cabin 1 comprising a front panel 31 arranged in front of the driver's seat 6, a left door 27L arranged to the left of the driver's seat 6, a right door 27R arranged to the right of the driver's seat 6, a left front pillar 13L provided between the front panel 31 and the left door 27L, and a right front pillar 13R provided between the front panel 31 and the right door 27R, wherein the left front pillar 13L and the right front pillar 13R are made of long material (long material for front pillar 34F) that curves so as to bulge forward over the entire area from the top to the bottom, and whose upper and lower halves have symmetrical curvatures with the middle of the vertical direction as the dividing line.

[0247] With this type of cabin 1, a single front pillar elongated material 34F can be processed into either the left front pillar 13L or the right front pillar 13R simply by selecting whether to invert the material longitudinally before cutting. In other words, the front pillar elongated material 34F is a raw material (a common raw material for both the left front pillar 13L and the right front pillar 13R) that can be selected for either the left front pillar 13L or the right front pillar 13R depending on whether it is inverted or not. Therefore, by simply molding and bending the common raw material front pillar elongated material 34F, the labor required for molding and bending is reduced to a single step. However, with conventional processing methods, the left front pillar 13L and the right front pillar 13R must be individually processed using separate dies or bent separately, which requires significant time and cost for the molding and bending. Therefore, in the cabin 1 of this embodiment, by using the long front pillar material 34F as the raw material common to the left front pillar 13L and the right front pillar 13R, it is possible to suppress an increase in manufacturing costs.

[0248] (Item A4) Cabin 1 comprising a rear panel 32 arranged behind the driver's seat 6, a left door 27L arranged to the left of the driver's seat 6, a right door 27R arranged to the right of the driver's seat 6, a left rear pillar 14L provided between the rear panel 32 and the left door 27L, and a right rear pillar 14R provided between the rear panel 32 and the right door 27R, wherein the left rear pillar 14L and the right rear pillar 14R use long materials of the same shape (long material for rear pillar 34R) that curve so as to bulge toward the rear.

[0249] (Item A5) The left rear pillar 14L and the right rear pillar 14R are made of a frame material in which the longitudinal ends of a long material (rear pillar long material 34R) are cut off and the portions other than the longitudinal ends have the same shape. This is the cabin 1 described in Item 4.

[0250] (Item A6) A cabin 1 comprising a rear panel 32 arranged behind the driver's seat 6, a left door 27L arranged to the left of the driver's seat 6, a right door 27R arranged to the right of the driver's seat 6, a left rear pillar 14L provided between the rear panel 32 and the left door 27L, and a right rear pillar 14R provided between the rear panel 32 and the right door 27R, wherein the left rear pillar 14L and the right rear pillar 14R are made of a long material (rear pillar long material 34R) that curves so as to bulge rearward over the entire area from the top to the bottom, and whose upper and lower halves have symmetrical curvatures with the midpoint in the vertical direction as the dividing line.

[0251] (Item A7) Cabin 1 equipped with a left door 27L arranged to the left of the driver's seat 6, a right door 27R arranged to the right of the driver's seat 6, a left side beam 18L provided at the upper end of the left door 27L, and a right side beam 18R provided at the upper end of the right door 27R, wherein the left side beam 18L and the right side beam 18R are made of long material of the same shape (long material for side beam 34S) that curves upward in the entire area from the front end to the rear end.

[0252] (Item A8) The left side beam 18L and the right side beam 18R are constructed from frame materials in which the longitudinal ends of a long material (long material for side beam 34S) are cut off and the portions other than the longitudinal ends have the same shape. This is the cabin 1 described in Item 7.

[0253] (Item A9) A cabin 1 equipped with a left door 27L arranged to the left of the driver's seat 6, a right door 27R arranged to the right of the driver's seat 6, a left side beam 18L provided at the upper end of the left door 27L, and a right side beam 18R provided at the upper end of the right door 27R, wherein the left side beam 18L and the right side beam 18R are made of long materials (long materials for side beams 34S) that curve upward in the entire area from the front end to the rear end, and whose curvatures are symmetrical in the front and rear halves with a dividing line halfway in the fore-and-aft direction.

[0254] With this type of cabin 1, simply by selecting whether to invert the long side beam 34S longitudinally before cutting, either the left side beam 18L or the right side beam 18R can be manufactured from a single long side beam material 34S. In other words, the long side beam material 34S is a raw material (a common raw material for both the left side beam 18L and the right side beam 18R) that can be selected for either the left side beam 18L or the right side beam 18R depending on whether it is inverted or not. Therefore, by molding and bending the common raw material for the long side beam 34S, the labor required for molding and bending is reduced to a single step. However, with conventional processing methods, the left side beam and the right side beam must be individually processed using separate dies or separately bent, which requires significant time and cost for the molding and bending. Therefore, in the cabin 1 of this embodiment, by using the long side beam material 34S as a raw material common to both the left side beam 18L and the right side beam 18R, rising manufacturing costs can be suppressed.

[0255] (Item A10) A cabin 1 according to any one of items A1 to A9, wherein the long members (each of the long member 34F for the front pillar, the long member 34R for the rear pillar, and the long member 34S for the side beam) are formed so that the radius of curvature at a midpoint in the longitudinal direction is larger than the radius of curvature at both ends in the longitudinal direction.

[0256] With such a cabin 1, the difference in curvature between the processed front pillar 13, rear pillar 14, or side beam 18 and the frame material to which it is connected can be reduced, and a cabin 1 can be obtained in which the frame materials are smoothly connected without giving the appearance of being bent.

[0257] (Item A11) The cabin 1 according to any one of Items A1 to A10, wherein the radius of curvature between both longitudinal ends and the middle portion of the elongated material is larger than that of the both longitudinal ends and smaller than that of the middle portion of the elongated material.

[0258] With such a cabin 1, even when connecting frame materials with different curvatures, the frame materials do not appear bent, and a smoothly connected cabin 1 can be obtained.

[0259] (Item A12) The cabin 1 according to any one of items A1 to A11, wherein the elongated material has a main seal surface 54 facing the inner surface of the end of any one of the front panel 31, the rear panel 32, the left door 27L, or the right door 27R, and a sub-seal surface 55 facing the end face of the end, and the end is provided with a door seal 46 (sealing member) including a main lip 47 that seals the main seal surface 54 of the elongated material and a sub-lip 48 that seals the sub-seal surface 55 of the elongated material.

[0260] In such a cabin 1, the intrusion of dust and moisture is reliably prevented by the main lip 47 and sub lip 48 provided in the door seal 46. In other words, even if dust or moisture passes through the sub lip 48, the dust or moisture that has infiltrated through the gap between the main lip 47 and the sub lip 48 is eliminated, so the intrusion of dust and moisture can be reliably prevented.

[0261] (Item B1) A vehicle comprising a left front pillar 13L and a right front pillar 13R (a pair of front pillars provided on the left and right sides) provided in front of the driver's seat 6, a front panel 31 fixed between the left front pillar 13L and the right front pillar 13R (between the left and right front pillars), and a left door 27L and a right door 27R (door panels) provided behind the left front pillar 13L and the right front pillar 13R (front pillars) so as to be able to open and close freely, and the left front pillar 13L and the right front pillar 13R (front pillars) are formed in a tubular shape with an irregular cross section. a first wall portion (60) that forms part of the outer periphery of the pipe; a second wall portion (63) that is arranged opposite the first wall portion (60) and that forms part of the outer periphery of the pipe; a first connecting wall (61) that connects one end of the first wall portion (60) to one end of the second wall portion (63); and a second connecting wall (62) that connects the other end of the first wall portion (60) to the other end of the second wall portion (63), the first connecting wall (61) and the second connecting wall (62) being formed to protrude outward from the pipe, the inner periphery of the first connecting wall (61) being formed in close contact with each other, and the inner periphery of the second connecting wall (62) being formed in close contact with each other.

[0262] With this cabin 1, the second wall portions 63 of the pipes forming the left front pillar 13L and the right front pillar 13R are recessed inward relative to the outwardly protruding first connecting wall 61 and second connecting wall 62, so that sufficient space can be secured outside the second wall portions 63 (recessed portions of the pipes) to arrange the pipes H1 to H3. Furthermore, even if these pipes H1 to H3 are arranged and then concealed with a cover 73, the outward protrusion of the cover 73 can be suppressed. Therefore, the left front pillar 13L can be formed narrow in the front-rear and left-right directions, which allows for a wider opening width for the entrance / exit door of the cabin 1 and a wider field of view from the front panel 31, improving the ease of getting in and out of the cabin 1 and visibility.

[0263] (Item B2) The cabin 1 according to Item B1, wherein the first connecting wall 61 and the second connecting wall 62 are formed to protrude in directions perpendicular to each other.

[0264] With such a cabin 1, it is possible to reliably fix the front panel 31 using the first connecting wall 61, and to reliably fix the left door 27L and the right door 27R using the second connecting wall 62.

[0265] (Item B3) The cabin 1 according to Item B1 or B2, wherein the second wall portion 63 is formed to protrude outward from the pipe.

[0266] With such a cabin 1, the outwardly protruding second wall portion 63 makes it possible to widen the cross-sectional area of ​​the irregular cross-section, thereby improving the bending strength of the left front pillar 13L and the right front pillar 13R.

[0267] (Item B4) The cabin 1 described in any one of Items B1 to B3, wherein the first wall portion 60 has a first standing wall portion 64 formed in an arc shape that bulges outward from the pipe, a second standing wall portion 65 that bends inward from one end of the first standing wall portion 64 in the width direction, and a third standing wall portion 66 that bends inward from the other end of the first standing wall portion 64 in the width direction.

[0268] In such a cabin 1, the first standing wall portion 64 having an arc-shaped cross section can realize a curved surface that smoothly connects with the front panel 31, making it possible to realize an appearance with excellent design. Furthermore, by providing the second standing wall portion 65 and the third standing wall portion 66 that are bent inward of the pipe, it is possible to improve the adhesion and sealing properties with the front panel 31 and the left door 27L and right door 27R.

[0269] (Item B5) The cabin 1 according to any one of Items B1 to B4, wherein the second wall portion 63 is provided with a peak portion 71 that protrudes most outward from the pipe, and a valley portion 72 that is recessed inward from the pipe further than the peak portion 71 is formed at the contact point between the first connecting wall 61 and the second wall portion 63 and at the contact point between the second connecting wall 62 and the second wall portion 63.

[0270] In such a cabin 1, the peaks 71 and valleys 72 can be utilized to separate and arrange different pipes (pipes H1 to H3) so as not to entangle them.

[0271] (Item B6) The second wall portion 63 is formed between the valley portion 72 and the peak portion 71 by a tangent line L passing through a point on the outer surface of the first wall portion 60. T The cabin 1 according to item B5, having a flat surface extending in a direction parallel to the

[0272] With such a cabin 1, it is possible to increase the bending strength (load resistance) of the left front pillar 13L and the right front pillar 13R.

[0273] (Item B7) The cabin 1 according to any one of Items B1 to B6, wherein the first connecting wall 61 comprises a single pipe wall that is folded and overlapped at the first fold portion 67, and an inner surface of the first connecting wall 61 located on one side of the first fold portion 67 and an inner surface of the first connecting wall 61 located on the other side of the first fold portion 67 are in close contact with each other; and the second connecting wall 62 comprises a single pipe wall that is folded and overlapped at the second fold portion 68, and an inner surface of the second connecting wall 62 located on one side of the second fold portion 68 and an inner surface of the second connecting wall 62 located on the other side of the second fold portion 68 are in close contact with each other.

[0274] With such a cabin 1, it is possible to process the left front pillar 13L and the right front pillar 13R at the same time using forming processing or the like from a tubular raw material (long material 34F for front pillar) with a sealed cross section.

[0275] (Item B8) A cabin 1 according to any one of Items B1 to B6, wherein the second wall portion 63 is configured separately from the first wall portion 60, the first connecting wall 61 is configured by joining one end of the first wall portion 60 and one end of the second wall portion 63 in a surface-to-surface contact state, and the second connecting wall 62 is configured by joining the other end of the first wall portion 60 and the other end of the second wall portion 63 in a surface-to-surface contact state.

[0276] With such a cabin 1, it is also possible to process the left front pillar 13L and the right front pillar 13R by bonding together plate-shaped raw materials.

[0277] (Item B9) The left door 27L and the right door 27R (door panel 27) have an inner surface facing the driver's seat 6 and a front end surface facing forward, and the main lip 47 of the door seal 46 is arranged on the inner surface of the front end of the door panel 27 so as to abut against the second connecting wall 62, and the sub-lip 48 of the door seal 46 is arranged on the front end surface so as to abut against the second standing wall portion 65. A cabin 1 described in any one of items B4 and items B5 to B8 which cite item B4.

[0278] In such a cabin 1, the intrusion of dust and moisture is reliably prevented by the main lip 47 and sub lip 48 provided in the door seal 46. In other words, even if dust or moisture passes through the sub lip 48, the dust or moisture that has infiltrated through the gap between the main lip 47 and the sub lip 48 is eliminated, so the intrusion of dust and moisture can be reliably prevented.

[0279] (Item B10) The cabin 1 according to any one of items B1 to B9, wherein the second wall portion 63 is provided with a cover 73 that covers the second wall portion 63 from the outside.

[0280] With such a cabin 1, the pipes H1 to H3, which tend to give a cluttered appearance, can be concealed by the cover 73, and the appearance of the interior of the cabin 1 can be improved.

[0281] (Item B11) The cabin 1 according to Item B10, which has a first cover wall 73a (the first cover wall 73a extending rearward from the outwardly protruding end of the pipe at the first connecting wall 61) facing the front panel 31 and a second cover wall 73b (the second cover wall 73b extending widthwise inward from the outwardly protruding end of the pipe at the second connecting wall 62) facing the door panel 27, wherein the first cover wall 73a is located widthwise outward of a line connecting the center of the driver's seat 6 to the outer widthwise end of the front panel 31 (a line connecting the center of the driver's seat 6 and the outwardly protruding end of the pipe at the first connecting wall 61, i.e., a front visibility boundary line FL), and the second cover wall 73b is located forward of a line connecting the center of the driver's seat 6 to the front end of the door panel 27 (a line connecting the center of the driver's seat 6 and the outwardly protruding end of the pipe at the second connecting wall 62, i.e., a side visibility boundary line SL).

[0282] In such a cabin 1, even if the cover 73 is provided, the first cover wall 73a of the cover 73 does not protrude so as to obstruct the forward field of view. Furthermore, the second cover wall 73b of the cover 73 does not protrude so as to obstruct the left entrance 28L, thereby narrowing the opening width of the left entrance 28L of the cabin 1. In other words, the cover 73 does not narrow the opening width of the left entrance 28L of the cabin 1 or the field of view of the front panel 31. Therefore, the width of the left front pillar 13L in the fore-and-aft direction and the width in the lateral direction as seen from the driver's seat 6 can be maintained wide, thereby improving the ease of getting in and out of the cabin 1 and the visibility.

[0283] (Item B12) A deformed pipe for use in a cabin 1, comprising: a first wall portion 60 that forms part of the outer periphery of the pipe; a second wall portion 63 that is arranged opposite the first wall portion 60 and that forms part of the outer periphery of the pipe; a first connecting wall 61 that connects one end of the first wall portion 60 to one end of the second wall portion 63; and a second connecting wall 62 that connects the other end of the first wall portion 60 to the other end of the second wall portion 63, wherein the first connecting wall 61 and the second wall portion 63 are formed to protrude outward from the pipe, and the inner periphery of the first connecting wall 61 is formed in close contact with the inner periphery of the second connecting wall 62.

[0284] If a specially shaped pipe is used for such a cabin 1, the width in the front-to-back direction and the width in the left-to-right direction can be reduced without reducing the bending strength of the pipe.

[0285] (Item B13) The profile pipe used in the cabin 1 according to Item B12, wherein the first connecting wall 61 and the second connecting wall 62 are formed to protrude in directions perpendicular to each other.

[0286] (Item B14) The profile pipe used in the cabin 1 according to item 12 or B13, wherein the second wall portion 63 is formed to protrude outward from the pipe.

[0287] In the case of a specially shaped pipe used in such a cabin 1, the cross-sectional area of ​​the pipe can be increased by the second wall portion 63 that protrudes outward from the pipe, thereby making it possible to increase the bending strength.

[0288] (Item B15) The irregular shaped pipe used in the cabin 1 described in any one of Items B12 to B14, wherein the first wall portion 60 has a first standing wall portion 64 formed in an arc shape that bulges outward from the pipe, a second standing wall portion 65 that bends inward from one end of the first standing wall portion 64 in the width direction, and a third standing wall portion 66 that bends inward from the other end of the first standing wall portion 64 in the width direction.

[0289] (Item B16) The deformed pipe used in the cabin according to any one of Items B12 to B15, wherein the second wall portion 63 has a peak portion 71 that protrudes most outward from the pipe, and a valley portion 72 that is recessed inward from the peak portion 71 into the pipe is formed at the contact point between the first connecting wall 60 and the second wall portion 63 and at the contact point between the second connecting wall 62 and the second wall portion 63.

[0290] (Item C1) A left rear pillar 14L and a right rear pillar 14R are disposed behind the driver's seat 6 at a distance to the left and right and are formed in a tubular shape extending in the up-down direction; a rear beam (rear beam 16) that connects the upper ends of the left rear pillar 14L and the right rear pillar 14R in the left-right direction and is formed to extend in the left-right direction; and a left side beam 18L that extends forward from the upper ends of the left rear pillar 14L and the right rear pillar 14R and is formed to be curved upward in the entire region from the front end to the rear end. The cabin (1) is longer in the front-to-rear direction than in the left-to-right direction and is provided with left reinforcing members (49L) and right reinforcing members (49R) that pass through the interior sides of the left rear pillar (14L) and right rear pillar (14R) and connect the rear beam (rear beam (16)) to the left side beam (18L) and right side beam (18R) in a diagonal manner, and the front portions of the left reinforcing members (49L) and right reinforcing members (49R) are connected near the centers of the left side beam (18L) and right side beam (18R) in the front-to-rear direction.

[0291] In such a cabin 1, the right reinforcing member 49R increases the load share borne by the left rear pillar 14L and the right rear pillar 14R, and reduces the load burden on the left front pillar 13L and the right front pillar 13R. As a result, the cabin 1 of this embodiment can suppress deformation and damage to the cabin 1 even in the event of a rollover, and can dramatically improve safety compared to conventional cabins.

[0292] (Item C2) The left reinforcing member 49L and the right reinforcing member 49R have a left first connection portion 82L and a right first connection portion 82R connected to the left side beam 18L and the right side beam 18R, a second connection portion 84 connected to the rear beam (the left portion and the right portion of the rear beam 16), and a central base 85 provided between the first connection portion 82 and the second connection portion 84, the central base 85 being joined to the outer peripheral surfaces of the left rear pillar 14L and the right rear pillar 14R on the interior side, and a distance (L1) between the first connection portion 82 and the central base 85 being greater than a distance (L2) between the second connection portion 84 and the central base 85.

[0293] With this cabin 1, the left reinforcing member 49L and the right reinforcing member 49R can further reduce the load on the left front pillar 13L and the right front pillar 13R, thereby making it possible to further improve safety compared to conventional cabins.

[0294] (Item C3) The left reinforcing member 49L and the right reinforcing member 49R have a roof seal surface 88 on which a roof seal 45 that seals between the roof 9 arranged above the driver's seat 6 is placed, and the roof seal surface 88 has: a first seal surface 89 that is provided between the first connection portion 82 and the second connection portion 84 and is formed flush with the upper surface of the left side beam 18L and the right side beam 18R; a second seal surface 90 that is provided between the first connection portion 82 and the second connection portion 84 and is formed flush with the upper surface of the rear beam 16; and a third seal surface 91 that is formed on the upper surface of the central base 85 and is formed between the first seal surface 89 and the second seal surface 90; and the cabin 1 described in Item C1 or Item C2, in which the first seal surface 89 and the third seal surface 91 are formed continuously, and the second seal surface 90 and the third seal surface 91 are also formed continuously.

[0295] With this type of cabin 1, the roof seal 45 can be continuously arranged around the driver's seat 6 without any sudden changes in height. In particular, in some conventional cabins, the height of the rear beam is lower than that of the right side beam, and in such conventional cabins, the seal member is sometimes interrupted around the rear beam, preventing sufficient sealing. However, with the cabin 1 of this embodiment, which uses the reinforcing member 49 having the roof sealing surface 88, the roof seal 45 can be arranged without interruption, making it possible to provide sufficient sealing.

[0296] (Item C4) Cabin 1 described in Item C3, in which the side beams 18 and the rear lower frame 17 (sometimes referred to as the rear beam) use frame members with a U-shaped cross section that open toward the inside of the cabin, the side beams 18 are provided with a first fixing plate 42 that closes the opening of the side beams 18 and to which the first connection part 82 is connected, and the rear lower frame 17 is provided with a second fixing plate 83 that closes the opening of the rear lower frame 17 and to which the second connection part 84 is connected.

[0297] With this type of cabin 1, the above-described reinforcing member 49 can be firmly fixed to the side beam 18 and the rear lower frame 17, and the reinforcing member 49 can be used to connect the rear beam 16, the upper part of the rear pillar 14, and the side beam 18. As a result, the reinforcing member 49 can be used to firmly support the side beam 18 against the rear beam 16 and the upper part of the rear pillar 14, making it possible to increase the load-bearing capacity of the cabin 1.

[0298] (Item C5) The cabin 1 according to Item C4, wherein the first connection portion 82 is provided in the middle of the first fixing plate 42 in the up-down direction, and the second connection portion 84 is provided in the middle of the second fixing plate 83 in the up-down direction.

[0299] With such a cabin 1, welding can be performed below the upper surface of the upper wall portion 39 of the side beam 18, so spatter debris generated during welding is less likely to adhere to the upper surface of the upper wall portion 39 of the side beam 18, making it possible to improve the sealing performance of the roof seal 45.

[0300] (Item D1) A cabin (1) comprising a front panel (31) arranged in front of the driver's seat (6) so as to curve forward in a convex manner, and a support structure (99) that supports the front panel (31), wherein the support structure (99) has a panel support frame (95) to which the front panel (31) is attached, and a pedal support portion (98) that supports a brake pedal (97) on the panel support frame (95), wherein the front panel (31) is formed as a single plate that has a cutout portion (100) at its lower end that opens downward, wherein the pedal support portion (98) has a support shaft (101) that supports the brake pedal (97) so that it can swing, and wherein the panel support frame (95) has an opening frame (102) that is shaped to fit the opening of the cutout portion (100) and is adhered to the periphery of the opening, and wherein the cabin (1) is positioned below the support shaft (101).

[0301] With such a cabin 1, the cutout 100 can be kept small, reducing the effort required for cutting the front panel 31 and making it less likely to break. Furthermore, if the cutout 100 is kept low and has a small area, the field of view of the front panel 31 can be widened, improving visibility from the cabin 1.

[0302] (Item D2) The cabin 1 according to Item D1, wherein the panel support frame 95 has the opening frame 102 arranged along the back surface of the front panel 31, and does not have a portion above the opening frame 102 that is arranged along the back surface of the front panel 31.

[0303] Regarding how low the cutout 100 should actually be, it is sufficient that the cutout 100 is positioned below the support shaft 101. In this case, in the cabin 1 of this embodiment, the opening frame 102 of the panel support frame 95 is positioned along the back surface of the front panel 31, but it is preferable that there is no portion above the opening frame 102 that is positioned along the back surface of the front panel 31. In other words, the opening frame 102 and the front panel 31 in front of the opening frame 102 are fixed in surface contact, but the panel support frame 95 is not provided in front of the front panel 31 even slightly above the opening frame 102, so that nothing obstructs the field of view from the front panel 31. According to the cabin 1 according to item D2, visibility from the cabin 1 can be reliably improved.

[0304] (Item D3) A cabin 1 described in Item D1 or Item D2, in which the panel support frame 95 has a base frame 103 connected to the periphery of the opening frame 102, and the base frame 103 has a frame plate 106 having a through hole 105 through which a steering shaft 104 extending from in front of the driver's seat 6 toward the front and downward passes, and the frame plate 106 is inclined so as to transition upward as it moves from the rear toward the top of the opening frame 102 to avoid interference with a clutch housing 107 arranged below the driver's seat 6.

[0305] With such a cabin 1, visibility from the front panel 31 is improved, the inclined frame plate 106 avoids physical interference with the clutch housing 107, and it is also possible to secure space below the frame plate 106 for installing components such as a universal joint.

[0306] (Item D4) The cabin 1 described in any one of Items D1 to D3, wherein the support shaft 101 is arranged with its axis oriented in the left-right direction, and the pedal support portion 98 has a left first frame 108 that supports the left end of the support shaft 101 against the left end of the base frame 103, a left second frame 109 that supports the left end of the opening frame 102 against the left first frame 108, a central frame 110 that supports the middle end of the support shaft 101 in the left-right direction against the central part of the base frame 103, a right first frame 111 that supports the right end of the support shaft 101 against the right end of the base frame 103, and a right second frame 112 that supports the right end of the opening frame 102 against the right first frame 111.

[0307] With such a cabin 1, by using five frames to provide support, namely the left first frame 108, the left second frame 109, the center frame 110, the right first frame 111, and the right second frame 112, it is possible to firmly support the support portion main body 118 (pedal support portion 98) at a position above and away from the base frame 103 (panel support frame 95).

[0308] (Item D5) The cabin 1 according to item D4, wherein a connecting reinforcement frame 113 is provided between the left first frame 108 and the right first frame 111 to connect both frames in the left-right direction.

[0309] In such a cabin 1, the support strength of the pedal support portion 98 is further improved by the connecting reinforcement frame 113.

[0310] (Item D6) A cabin 1 described in any one of Items D1 to D5, in which a left front pillar 13L and a right front pillar 13R (front pillars) that support the front panel 31 are arranged at the left and right ends of the front panel 31, and a front beam 15 that is connected to the upper ends of the left front pillar 13L and the right front pillar 13R (upper ends of the left and right front pillars) and that curves upward in a convex shape is provided at the upper end of the front panel 31, a roof 9 is arranged above the driver's seat 6, and the weight of the roof 9 is supported by the left front pillar 13L, right front pillar 13R (left and right front pillars) and the front panel 31 via the front beam 15.

[0311] With such a cabin 1, the weight of the roof 9, the air conditioner installed inside the roof 9, and even the weight of the front panel 31 itself can be distributed and supported by the left front pillar 13L and the right front pillar 13R without being concentrated only on the front panel 31.

[0312] (Item D7) The brake pedals 97 include a left brake pedal 97L that operates the left brake and a right brake pedal 97R that operates the right brake, and an interlocking member 114 that causes the left brake pedal 97L and the right brake pedal 97R to operate in conjunction with each other is provided between the left brake pedal 97L and the right brake pedal 97R, and an interlock release pedal 124 that releases the interlock between the left brake pedal 97L and the right brake pedal 97R by the interlocking member 114 is provided on either the left or right side of the support structure 99, and the interlock release pedal 124 that releases the interlock between the left brake pedal 97L and the right brake pedal 97R by the interlocking member 114 is provided on either the left or right side of the support structure 99, and the frame of the pedal support part 98 on which the interlock release pedal 124 is provided is formed so that a midpoint in the up-down direction is bent inward in the left-right direction. Cabin 1 described in any of Items D1 to D6.

[0313] (Item D8) A cabin 1 described in any one of Items D1 to D7, in which a clutch member for switching power transmission is provided at the left end of the support shaft 101, and the pedal support portion provided on the right side of the same support shaft 101 where the clutch member is provided is formed so that the middle side in the up-down direction is bent inward in the left-right direction.

[0314] With such a cabin 1, even if there are components such as an interlock release pedal 124 or a clutch member on one of the left and right sides of the support structure 99, the frame of the pedal support part 98 does not get in the way when stepping on the interlock release pedal 124 or the clutch member, and interlock release or operation of the clutch member can be performed reliably.

[0315] (Item D9) Cabin 1 described in any one of Items D1 to D8, in which the front panel 31 is curved so that the middle of the vertical direction protrudes forward from the lower end, and the opening frame 102 is in a forward-leaning position so that the middle of the vertical direction protrudes forward from the lower end in accordance with the curvature of the front panel 31.

[0316] (Item D10) A cabin 1 described in Item D6 or any of Items D7 to D9 which cite Item D6, in which the front panel 31 is curved so that the middle of the vertical direction protrudes forward relative to the lower end, and the left front pillar 13L and the right front pillar 13R (front pillars) are in a forward-leaning position so that the middle of the vertical direction protrudes forward relative to the lower end in accordance with the curvature of the front panel 31.

[0317] With such a cabin 1, even for a full-round type front panel 31 that curves so that the center protrudes forward, the front panel 31 can be securely fixed by tightly contacting the periphery of the cutout portion 100 of the front panel 31 with the opening frame 102 of the panel support frame 95 and by tightly contacting both ends of the front panel 31 with the left front pillar 13L and the right front pillar 13R.

[0318] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. In particular, in the embodiments disclosed herein, matters not explicitly disclosed, such as operating conditions, operating conditions, various parameters, dimensions, weights, volumes of components, etc., do not deviate from the scope of ordinary practice by a person skilled in the art, and values ​​that can be easily assumed by a person skilled in the art are used.

[0319] 1 Cabin 6 Driver's seat 13 Front pillar 13L Left front pillar 13R Right front pillar 14 Rear pillar 14L Left rear pillar 14R Right rear pillar 18 Side beam 18L Left side beam 18R Right side beam 27L Left door 27R Right door 31 Front panel 32 Rear panel 34F Long material for front pillar 34S Long material for side beam 34R Long material for rear pillar 46 Door seal 47 Main lip 48 Sub lip 54 Main seal surface 55 Sub seal surface

Claims

1. A cabin comprising a front panel disposed in front of a driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left front pillar provided between the front panel and the left door, and a right front pillar provided between the front panel and the right door, wherein the same-shaped elongated members that curve so as to bulge forward are used for the left front pillar and the right front pillar.

2. The cabin according to claim 1, wherein the left front pillar and the right front pillar are composed of frame members in which the longitudinal ends of the elongated members are cut off and the portions other than the longitudinal ends have the same shape.

3. A cabin comprising a front panel disposed in front of a driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left front pillar provided between the front panel and the left door, and a right front pillar provided between the front panel and the right door, wherein the same-shaped elongated members that curve so as to bulge forward in the entire region from the upper end to the lower end are used for the left front pillar and the right front pillar, and the curvatures of the upper half and the lower half are symmetric with each other with the middle in the vertical direction as the boundary.

4. A cabin comprising a rear panel disposed behind a driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left rear pillar provided between the rear panel and the left door, and a right rear pillar provided between the rear panel and the right door, wherein the same-shaped elongated members that curve so as to bulge backward are used for the left rear pillar and the right rear pillar.

5. The cabin according to claim 4, wherein the left rear pillar and the right rear pillar are composed of frame members in which the longitudinal ends of the elongated members are cut off and the portions other than the longitudinal ends have the same shape.

6. A cabin comprising a rear panel disposed behind the driver's seat, a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left rear pillar provided between the rear panel and the left door, and a right rear pillar provided between the rear panel and the right door, wherein the left rear pillar and the right rear pillar are formed of elongate members that curve rearwardly so as to bulge in the entire region from the upper end to the lower end, and the curvature of the upper half and the lower half is symmetric with respect to the midpoint in the vertical direction.

7. A cabin comprising a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left side beam provided at the upper end of the left door, and a right side beam provided at the upper end of the right door, wherein the left side beam and the right side beam are formed of elongate members of the same shape that curve upwardly so as to bulge in the entire region from the front end to the rear end.

8. The cabin according to claim 7, wherein the left side beam and the right side beam are composed of frame members in which the longitudinal ends of the elongate members are cut off and the portions other than the longitudinal ends have the same shape.

9. A cabin comprising a left door disposed to the left of the driver's seat, a right door disposed to the right of the driver's seat, a left side beam provided at the upper end of the left door, and a right side beam provided at the upper end of the right door, wherein the left side beam and the right side beam are formed of elongate members that curve upwardly so as to bulge in the entire region from the front end to the rear end, and the curvature of the front half and the rear half is symmetric with respect to the midpoint in the front-rear direction.

10. The cabin according to any one of claims 1 to 9, wherein the elongate member is formed such that the radius of curvature at the middle portion in the longitudinal direction is larger than the radius of curvature at both longitudinal ends.

11. The cabin according to claim 10, wherein the radius of curvature between both longitudinal ends and the middle portion in the elongate member is larger than that at both ends and smaller than that at the middle portion in the longitudinal direction.

12. The long member has a main seal surface facing the inner surface of the end portion and a sub-seal surface facing the end surface of the end portion with respect to any end portion of the front panel, the rear panel, the left door, or the right door, and a door seal including a main lip for sealing the main seal surface of the long member and a sub-lip for sealing the sub-seal surface of the long member is provided at the end portion. The cabin according to claim 11.

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