Cabin

Abstract

To suppress deformation of a cabin when a load is applied thereto from the lateral side.SOLUTION: A cabin 1 of the present invention includes: rear pillars 14L, 14R disposed at a distance therebetween in a left-right direction behind a driver seat 6 and formed in a tubular shape extending in a vertical direction; a rear beam 16 connecting upper ends of the rear pillars 14L, 14R and formed to extend in the left-right direction; and side beams 18L, 18R extending forward from the upper ends of the rear pillars 14L, 14R and formed to be curved upward in the entire region from a front end to a rear end. The cabin 1 is formed to be longer in a front-rear direction than in the left-rear direction and includes reinforcement members 49L, 49R passing through an interior side of the rear pillars 14L, 14R and connecting the rear beam 16 and the side beams 18L, 18R diagonally therebetween. Front portions of the reinforcement members 49L, 49R are connected at locations near the center of the side beams 18L, 18R in the front-rear direction.SELECTED DRAWING: Figure 21

Description

Technical Field

[0001] The present invention relates to a cabin used for, for example, a tractor, a wheel loader, a backhoe, etc., and particularly to a cabin having a reinforcing structure at the upper part of a rear pillar.

Background Art

[0002] Conventionally, as a cabin for a tractor or the like, the one disclosed in Patent Document 1 is known.

[0003] The cabin of Patent Document 1 mainly includes a floor plate, a fender plate, a front pillar, and a rear pillar. The rear pillar supports the rear end portion of the roof that serves as the top surface. The lower end of the left rear pillar is attached to the fender plate. Also, the lower end of the right rear pillar is attached to the fender plate. And these left and right rear pillars are connected to each other via a rear beam. Further, each rear pillar is also connected to the front pillar via a side beam. The rear pillar constitutes a part of a door frame (a frame in which a side glass serving as a door is housed). Note that both end portions of the rear glass are fixed to the left and right rear pillars.

[0004] That is, the rear end portion of the cabin of Patent Document 1 is supported by connecting the left and right rear pillars to each other with a rear beam and connecting the space between them and the front pillar via a side beam.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, the cabin of the tractor in Patent Document 1 is merely a structure in which a rear pillar corresponding to a column, a rear beam corresponding to a beam, and a side beam are simply connected. When a force is applied from the side during a rollover or the like, the cabin may be deformed.

[0007] Therefore, in the tractor of Patent Document 1, a seal plate or the like that functions as a rib is provided on the fender plate to increase the strength of the cabin.

[0008] However, the reinforcement by the seal plate is for the lower end of the rear pillar where the fender plate is provided, and the reinforcement for the upper end of the rear pillar is not sufficient.

[0009] The present invention has been made in view of the above problems, and an object of the present invention is to provide a cabin that does not cause deformation even when a load acts from the side by providing a reinforcing member that fixes a side beam and a rear upper beam in a cross shape on the upper part of a rear pillar.

Means for Solving the Problems

[0010] The technical means of the present invention for solving the above-described technical problems is characterized by the following points.

[0011] The cabin of the present invention includes rear pillars that are arranged at a distance from each other on the left and right behind the driver's seat and are formed in a tubular shape extending in the vertical direction, a rear beam that connects the upper ends of the rear pillars in the left-right direction and is formed to extend in the left-right direction, and a side beam that extends forward from the upper ends of the rear pillars and is formed to curve upward in the entire region from the front end to the rear end. The cabin is formed longer in the front-rear direction than in the left-right direction, and includes a reinforcing member that connects the rear beam and the side beam in a cross shape through the indoor side of the rear pillar. The front part of the reinforcing member is connected to the vicinity of the central part in the front-rear direction of the side beam.

[0012] The reinforcing member has a first connection portion connected to the side beam, a second connection portion connected to the rear beam, and a central base portion provided between the first connection portion and the second connection portion. The central base portion is joined to the outer peripheral surface on the interior side of the rear pillar. The distance between the first connection portion and the central base portion may be greater than the distance between the second connection portion and the central base portion.

[0013] The reinforcing member has a roof seal surface on which a seal member for sealing between the reinforcing member and a roof disposed above the driver's seat is placed. The roof seal surface is provided between the first connection portion and the second connection portion, and includes a first seal surface portion formed flush with the upper surface of the side beam, a second seal surface portion provided between the first connection portion and the second connection portion and formed flush with the upper surface of the rear beam, and a third seal surface portion formed on the upper surface of the central base portion and between the first seal surface portion and the second seal surface portion. The first seal surface portion and the second seal surface portion are substantially flush with each other, and the first seal surface portion and the second seal surface portion may be substantially flush with each other.

[0014] For the side beam and the rear beam, a frame member having a U-shaped cross section that opens toward the interior side is used. The side beam is provided with a first fixing plate that closes the opening of the side beam and to which the first connection portion is connected. The rear beam may be provided with a second fixing plate that closes the opening of the rear beam and to which the second connection portion is connected.

[0015] The first connection portion is provided at an intermediate position in the vertical direction of the first fixing plate, and the second connection portion may be provided at an intermediate position in the vertical direction of the second fixing plate.

Advantages of the Invention

[0016] According to the cabin of the present invention, by providing a reinforcing member that fixes the side beam and the rear upper beam in a crosswise manner at the upper part of the rear pillar, there is no fear of deformation even when a load acts from the side.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

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Figure 8A

Figure 8B

Figure 9A

Figure 9B

Figure 10A

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Figure 10C

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Figure 19B

Figure 20A

Figure 20B

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Figure 27

Mode for Carrying Out the Invention

[0018] Hereinafter, the cabin 1 of the present embodiment will be described with appropriate reference to the drawings.

[0019] FIG. 1 shows a side view of a tractor 2 having the cabin 1 of 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, as the work machine on which the cabin 1 of the present invention is mounted, a wheel loader, a backhoe, or the like may be used.

[0020] In this specification, the direction of arrow A1 in FIG. 1 (the forward direction of the tractor 2) is defined as the front, the direction of arrow A2 in FIG. 1 (the reverse direction of the tractor 2) is defined as the rear, and the direction of arrow A3 in FIG. 1 is defined as the front-rear direction for the explanation It will be clarified. Therefore, the front side on the plane of FIG. 1 is the left side when explaining the tractor 2 and the cabin 1, and the back side on the plane of FIG. 1 is the right side when explaining the tractor 2 and the cabin 1. These directions are consistent with the directions seen from the operator OP who boarded the tractor 2 (the driver's seat 6) (hereinafter, the person who boards the tractor 2 and drives or operates the tractor 2 is referred to as the operator OP). Also, the horizontal direction orthogonal to the front-rear direction indicated by the arrow A3 is defined as the width direction when explaining the tractor 2 and the cabin 1. Further, the direction from the central part in the width direction of the tractor 2 to the right part or the left part is explained as the outward width direction. In other words, the outward width direction is the direction in the width direction that is away from the center of the tractor 2. The direction opposite to the outward width direction is explained as the inward width direction. In other words, the inward width direction is the direction in the width direction that approaches the center of the tractor 2.

[0021] As shown in FIG. 1, the tractor 2 has a drivable body (vehicle body) 3. The body 3 has a prime mover E1 and a transmission case 4.

[0022] The prime mover E1 generates a driving force for running the body 3, and in this embodiment, a diesel engine is used. The prime mover E1 is located at the front part of the tractor 2 and is covered by the bonnet 10. The bonnet 10 is formed in a curved shape with the upper surface protruding slightly upward and has a space capable of storing the prime mover E1 inside. In the tractor 2 of this embodiment, the prime mover E1 is stored in the space inside the bonnet 10.

[0023] Note that, instead of the diesel engine used in this embodiment, an electric motor may be used for the prime mover E1, or a hybrid type in which a diesel engine and an electric motor are combined in a complex manner may be used.

[0024] The transmission case 4 is configured by directly connecting, for example, a flywheel housing that houses a flywheel, a clutch housing 107 (see FIGS. 1 and 27) that houses a clutch that intermittently transmits the power of the prime mover E1 transmitted through the flywheel, and a transmission case that houses a transmission device that shifts the power transmitted through the clutch.

[0025] As shown in FIG. 1, the tractor 2 has a traveling device 5 that supports the machine body 3 so as to be able to travel. The traveling device 5 of the tractor 2 illustrated in FIG. 1 is of a wheel type (four-wheel type) having a left front wheel 11L and a right front wheel 11R disposed at the front portion of the machine body 3, and a left rear wheel 12L and a right rear wheel 12R disposed at the rear portion of the machine body 3. In other words, the tractor 2 of the present embodiment includes a traveling device 5 that travels on four wheels, namely, the left front wheel 11L, the right front wheel 11R, the left rear wheel 12L, and the right rear wheel 12R.

[0026] As shown in FIG. 1, the cabin 1 is a room where the operator OP enters to drive and operate the machine body 3, and is mounted on the rear portion of the machine body 3 in the case of the present embodiment. A driver's seat 6 on which the operator OP sits is provided at the rear portion of the interior of the cabin 1 (referred to as the cabin interior). In front of the driver's seat 6, for example, a steering wheel 7 for steering the left front wheel 11L and the right front wheel 11R is provided.

[0027] As shown in FIGS. 1 and 2, the cabin 1 has a cabin frame 8 in which long frame members are combined three-dimensionally and in a lattice shape. That is, the cabin frame 8 constitutes the framework (outer skeleton) of the cabin 1 and has a plurality of long frame members. Further, panel members such as a front panel 31 and a door panel 27 described later are disposed between the frame members combined three-dimensionally and in a lattice shape on the cabin frame 8. Further, a roof 9 is provided on the upper portion of the cabin frame 8. The cabin frame 8 of the present embodiment is a four-pillar type without a center pillar (quarter pillar) as shown in FIG. 2.

[0028] As shown in FIGS. 2 to 6 (particularly in detail in FIG. 2), the cabin frame 8 has a plurality of long frame members. In the case of this embodiment, the frame members constituting the cabin frame 8 are the left front pillar 13L, the right front pillar 13R, the left rear pillar 14L, the right rear pillar 14R, the front beam 15, the rear beam 16, the rear lower frame 17 (rear beam), the left side beam 18L, the right side beam 18R, the left side lower beam 19L (left side lower frame), and the right side lower beam 19R (right side lower frame), a total of 11 members. Hereinafter, each frame member constituting the cabin frame 8 will be described in detail.

[0029] As shown in detail in FIGS. 2 to 5, at the front part 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 provided. The left front pillar 13L and the right front pillar 13R are arranged side by side with a space therebetween in the width direction and are both arranged so as to extend along the vertical direction. The left front pillar 13L is provided at the left front corner of the cabin 1. Also, the right front pillar 13R is provided at the right front corner of the cabin 1. A front beam 15 is spanned between the upper part of the left front pillar 13L and the upper part of the right front pillar 13R. That is, the upper part of the left front pillar 13L and the upper part of the right front pillar 13R are connected to each other left and right by the front beam 15.

[0030] Incidentally, hereinafter, the left front pillar 13L and the right front pillar 13R may be collectively referred to as the front pillar 13.

[0031] As shown in detail in FIGS. 2, 3, 5, and 6, at the rear of the cabin frame 8 (behind the driver's seat 6), a left rear pillar 14L and a right rear pillar 14R are provided. The left rear pillar 14L and the right rear pillar 14R are arranged side by side with a space therebetween in the width direction, and are both arranged so as to extend along the vertical direction. The left rear pillar 14L is provided at the left rear corner of the cabin 1. Also, the right rear pillar 14R is provided at the right rear corner of the cabin 1. A rear beam 16 is spanned between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. That is, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected to each other left and right by the rear beam 16. Also, a rear lower frame 17 is spanned between the lower part of the left rear pillar 14L and the lower part of the right rear pillar 14R. That is, the lower part of the left rear pillar 14L and the lower part of the right rear pillar 14R are connected to each other left and right by the rear lower frame 17.

[0032] Incidentally, hereinafter, the left rear pillar 14L and the right rear pillar 14R may be collectively referred to as the rear pillar 14.

[0033] As shown in detail in FIGS. 2, 3, and 5, on the upper part of the cabin frame 8, a left side beam 18L and a right side beam 18R are provided. The left side beam 18L and the right side beam 18R are arranged side by side with a space therebetween in the width direction, and are both arranged so as to extend along the front-rear direction. The left side beam 18L is curved such that the middle part in the front-rear direction bulges upward compared to the front end and the rear end. Also, the right side beam 18R is curved such that the middle part in the front-rear direction bulges upward compared to the front end and the rear end.

[0034] The left side beam 18L is spanned between the upper part of the left front pillar 13L and the upper part of the left rear pillar 14L. That is, the upper part of the left front pillar 13L and the upper part of the left rear pillar 14L are connected to each other front and rear by the left side beam 18L.

[0035] The right side beam 18R is spanned between the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R. That is, the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R are connected front and rear by the right side beam 18R.

[0036] Hereinafter, the left side beam 18L and the right side beam 18R may be collectively referred to as the side beam 18.

[0037] As shown in detail in FIGS. 2 and 3, a left side lower beam 19L and a right side lower beam 19R are provided at the lower part 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 space therebetween in the width direction.

[0038] The left side lower beam 19L is formed so as to draw an arc from the lower part of the left rear pillar 14L toward the front lower side. That is, the left side lower beam 19L extends so as to shift downward as it goes forward from the lower part of the left rear pillar 14L. And the lower end of the left side lower beam 19L extending so as to shift downward is connected in the front-rear direction to the lower end of the left front pillar 13L via the left connecting frame 20L.

[0039] The right side lower beam 19R is formed so as to draw an arc from the lower part of the right rear pillar 14R toward the front lower side. That is, the right side lower beam 19R extends so as to shift downward as it goes forward from the lower part of the right rear pillar 14R. And the lower end of the right side lower beam 19R extending so as to shift downward is connected in the front-rear direction to the lower end of the right front pillar 13R via the right connecting frame 20R.

[0040] Hereinafter, the left side lower beam 19L and the right side lower beam 19R are collectively referred to as the side lower beam 19.

[0041] As shown in FIG. 2, a left rear wheel fender 21L covering the left rear wheel 12L is fixed to the lower surface of the left side lower beam 19L and the lower end portion of the left rear pillar 14L. Further, a right rear wheel fender 21R covering the right rear wheel 12R is fixed to the lower surface of the right side lower beam 19R and the lower end portion of the right rear pillar 14R.

[0042] Further, as shown in detail in FIGS. 2, 4, 5, and 6, a front beam 15 is provided at the front part and a rear beam 16 is provided at the rear part on the upper part of the cabin frame 8.

[0043] The front beam 15 and the rear beam 16 are arranged side by side with a space therebetween in the front-rear direction, and are each formed as a long frame member extending along the left-right direction. The front beam 15 is curved such that the middle side in the left-right direction bulges upward compared to the left end and the right end. Further, the rear beam 16 extends linearly along the left-right direction with almost no change in height in the up-down direction.

[0044] The front beam 15 is spanned between the upper part of the left front pillar 13L and the upper part of the right front pillar 13R. That is, the upper part of the left front pillar 13L and the upper part of the right front pillar 13R are connected to the left and right by the front beam 15.

[0045] The rear beam 16 is spanned between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. That is, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected to the left and right by the rear beam 16.

[0046] That is, the cabin frame 8 of the present embodiment is formed by combining frame members such as the above-described 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. ront 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.

[0047] As shown in FIGS. 2 and 5, a floor seat 22 is provided between the left rear wheel fender 21L and the right rear wheel fender 21R. The floor seat 22 is arranged along the horizontal direction below the driver's seat 6, and the driver's seat 6 is attached onto the floor seat 22. The rear part of the floor seat 22 extends in an inclined manner toward the rear upper side and is located on the back side of the driver's seat 6. From the front lower end of the floor seat 22 forward, a step 23 that forms a floor at a position lower than the floor seat 22 is provided. The feet of the operator OP seated on the driver's seat 6 are placed on the step 23.

[0048] As shown in FIGS. 1, 3, 4, and 6, the roof 9 is provided on the upper part of the cabin frame 8, which can prevent wind, rain, and direct sunlight from entering the cabin 1. The roof 9 has an inner roof 24 that forms the ceiling part etc. of the interior of the cabin 1 and an outer roof 25 that forms the upper wall etc. of the ceiling part. A hollow space is formed between the inner roof 24 and the outer roof 25, and a space where an air conditioner 26 (air-conditioning device) for air-conditioning the air in the cabin can be arranged is formed.

[0049] As shown in FIGS. 1, 2, and 5, the cabin 1 of the present embodiment is configured to enable the operator OP to board from both the left and right sides, and has a left boarding and alighting opening 28L on the left side surface of the cabin 1 and a right boarding and alighting opening 28R on the right side surface of the cabin 1. A left door 27L (left door panel) that closes the left boarding and alighting opening 28L is provided at the left boarding and alighting opening 28L. A right door 27R (right door panel) that closes the right boarding and alighting opening 28R is provided at the right boarding and alighting opening 28R.

[0050] The left entrance / exit 28L is an opening surrounded by the left front pillar 13L, the left side beam 18L, the left rear pillar 14L, the left side lower beam 19L, and the left connecting frame 20L, and opens to the left. The left entrance / exit 28L can be closed by the left door 27L. The left door 27L is supported by the left rear pillar 14L via two door hinges at the upper and lower positions. The two door hinges at the upper and lower positions are the first door hinge 29L provided at the upper part of the left rear pillar 14L and the second door hinge 30L provided at the lower part of the first door hinge 29L. That is, the left door 27L can open and close the left entrance / exit 28L by swinging the front end in the left - right direction with respect to the rear end where the first door hinge 29L and the second door hinge 30L are provided.

[0051] The right entrance / exit 28R is an opening surrounded by the right front pillar 13R, the right side beam 18R, the right rear pillar 14R, the right side lower beam 19R, and the right connecting frame 20R, and opens to the right. The right entrance / exit 28R can be closed by the right door 27R. The right door 27R is supported by the right rear pillar 14R via two door hinges at the upper and lower positions. The two door hinges at the upper and lower positions are the first door hinge 29R provided at the upper part of the right rear pillar 14R and the second door hinge 30R provided at the lower part of the first door hinge 29R. That is, the right door 27R can open and close the right entrance / exit 28R by swinging the front end in the left - right direction with respect to the rear end where the first door hinge 29R and the second door hinge 30R are provided.

[0052] The above - mentioned left door 27L and right door 27R are formed by panels having light transmittance such as tempered glass and acrylic glass, and it is possible to ensure good visibility from the interior of the cabin 1 to the outside of the vehicle.

[0053] As shown in FIG. 5, the cabin 1 of the present embodiment includes a front panel 31 at the front part of the cabin frame 8 and a rear panel 32 at the rear part of the cabin frame 8.

[0054] The front panel 31 is disposed between a left front pillar 13L and a right front pillar 13R that are spaced apart from each other left and right, and is supported from the left and right by the left front pillar 13L and the right front pillar 13R. Further, the upper edge of the front panel 31 is fixed to a front beam 15 disposed above the front panel 31. Similar to the above-described left door 27L and right door 27R, the front panel 31 is formed of a panel having light transmissibility such as tempered glass or acrylic glass, ensuring good visibility from the interior of the cabin 1 to the outside of the vehicle (front).

[0055] The front panel 31 of the present embodiment is formed in a curved surface shape that bulges forward. That is, when the front panel 31 is cut along the horizontal direction, the horizontal cross-section of the front panel 31 has an arc shape in which the central side in the left-right direction protrudes forward compared to the left end and the right end. Further, when the front panel 31 is cut along the vertical direction, the vertical cross-section of the front panel 31 has an arc shape in which the central side in the up-down direction protrudes forward compared to the upper end and the lower end. By forming the front panel 31 into a curved surface that bulges forward, it is possible to improve the visibility from the interior of the cabin 1 to the front outside of the vehicle, particularly downward.

[0056] Next, the configurations of the left front pillar 13L and the right front pillar 13R will be described in detail.

[0057] 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 in the width direction of the cabin 1 and is orthogonal to the width direction.

[0058] Note that, as shown in FIGS. 4 to 6, the reference plane S is a vertical plane that passes through the center in the width direction of the cabin 1 and is orthogonal to the width direction, and is located in the middle in the left-right direction of the cabin 1.

[0059] As shown in FIGS. 8A and 8B, the left front pillar 13L and the right front pillar 13R are formed to be long in the vertical direction, and are formed in an arc shape that curves such that the central side 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 respectively provided at the upper portions of the left front pillar 13L and the right front pillar 13R.

[0060] When the middle side in the vertical direction of the left front pillar 13L shown in FIG. 8A is cut along the cutting line connecting "C" and "C" in the figure, a cross-section as shown in FIG. 9A is obtained. Similarly, like the left front pillar 13L, when the middle side in the vertical direction of the right front pillar 13R is cut at the same height as the left front pillar 13L along the cutting line connecting "C'" and "C'" in the figure, a cross-section as shown in FIG. 9B is obtained.

[0061] The cross-section of the left front pillar 13L in FIG. 9A and the cross-section of the right front pillar 13R in FIG. 9B are both irregular cross-sections, and the cross-sectional shapes will not be congruent even when inverted or rotated. Note that the "irregular cross-section" in this specification refers to a shape such that, no matter how it is inverted with respect to any straight line or rotated about any point, the shape before inversion or rotation and the shape after inversion or rotation will not be the same, that is, a shape that does not have any line symmetry or rotational symmetry.

[0062] Note that the left front pillar 13L or the right front pillar 13R individually does not have any line symmetry or rotational symmetry. However, when the cross-section of the left front pillar 13L is inverted left and right, it becomes congruent with the cross-section of the right front pillar 13R, and when the cross-section of the right front pillar 13R is inverted left and right, it becomes congruent with the cross-section of the left front pillar 13L. That is, the cross-sections of the left front pillar 13L and the right front pillar 13R are in a left-right line-symmetric relationship with each other.

[0063] The reason why the cross-section of the left front pillar 13L and the cross-section of the right front pillar 13R are in a line-symmetric relationship with respect to the left and right is that the left front pillar 13L and the right front pillar 13R are formed from long members of the same shape. That is, the left front pillar 13L and the right front pillar 13R are processed from a long member (front pillar long member 34F), which is a common raw material (processing raw material).

[0064] Next, the long member will be described.

[0065] In addition, in the present embodiment, similar to the left front pillar 13L and the right front pillar 13R, for the left side beam 18L and the right side beam 18R, and the left rear pillar 14L and the right rear pillar 14R, long members of the same shape are used as the raw materials common to the left and right frame members.

[0066] Hereinafter, in order to distinguish the long members of the left front pillar 13L and the right front pillar 13R from the long members (rear pillar long members 34R) of the left rear pillar 14L and the right rear pillar 14R and the long members (side beam long members 34S) of the left side beam 18L and the right side beam 18R, which will be described later, they are referred to as front pillar long members 34F.

[0067] As shown in FIG. 10A, the long member 34F for the front pillar is formed of a pipe material that curves such that the middle part in the vertical direction bulges forward with respect to the upper and lower ends. The long member 34F for the front pillar in the present embodiment curves with the same curvature in the entire region from the upper end to the lower end, and the curvatures of the upper half and the lower half are symmetric up and down with the middle in the vertical direction as the boundary. The long member 34F for the front pillar has a deformed cross-section as shown in FIGS. 9A and 9B, and its interior is formed hollow. The left front pillar 13L and the right front pillar 13R are selectively processed by changing the way of end cutting for the long member 34F for the front pillar having the same shape. Specifically, when the left front pillar 13L is processed by cutting one end and the other end in the longitudinal direction of the long member 34F for the front pillar, if the cutting method for each end in the longitudinal direction is reversed and the end is cut, the right front pillar 13R can be obtained. The procedure for selectively processing the left front pillar 13L and the right front pillar 13R by reversing the cutting method from the long member 34F for the front pillar having the same shape will be described hereinafter.

[0068] FIGS. 10A and 10B are diagrams showing the procedure for processing the left front pillar 13L from the long member 34F for the front pillar. In FIGS. 10A and 10B, the processing is performed in the order from FIG. 10A to FIG. 10B.

[0069] As shown in FIG. 10A, the long member 34F for the front pillar is formed as a pipe material that is longer in the longitudinal direction than the left front pillar 13L and the right front pillar 13R.

[0070] As shown in FIG. 10B, when processing the left front pillar 13L from the long member 34F for the front pillar, cutting is performed at the first cut line 35 (see FIG. 10A) slightly below the upper end of the long member 34F for the front pillar, and the first end piece 36 located above the first cut line 35 is cut off and removed. Also, slightly above the lower end of the long member 34F for the front pillar Perform cutting along the second cut line 37 (see FIG. 10A), and cut and remove the second end piece 38 located below the second cut line 37.

[0071] As shown in FIG. 10C, after removing the first end piece 36 and the second end piece 38 by the cutting shown in FIG. 10B, if a mirror mounting portion 33 or the like is attached to a predetermined position at the upper part of the long member 34F for the front pillar after cutting, the left front pillar 13L can be processed.

[0072] Next, a procedure for processing the right front pillar 13R from the long member 34F for the front pillar will be described with reference to FIGS. 11A to 11D. Also in FIGS. 11A to 11D, it is assumed that the processing is performed in the order from FIG. 11A to FIG. 11D.

[0073] As shown in FIG. 11A, first, prepare the same long member 34F for the front pillar as in FIG. 10A. Here, the long member 34F for the front pillar in the present embodiment is in an arc shape that is curved with the same curvature from the upper end to the lower end. That is, the long member 34F for the front pillar has a vertically line-symmetric structure with respect to the inversion reference line M that passes horizontally through the middle between the upper end and the lower end (the middle of the upper and lower). Therefore, even if the long member 34F for the front pillar is inverted vertically with the inversion reference line M as the boundary, the curved state such as the curvature does not change before and after the inversion.

[0074] However, the long member 34F for the front pillar has, for example, an irregular cross-section as shown in FIG. 9A. When the long member 34F for the front pillar is inverted vertically with the inversion reference line M as the boundary, the irregular cross-section is also inverted vertically. And it changes from the irregular cross-section as shown in FIG. 9A to the irregular cross-section as shown in FIG. 9B. The long member 34F for the front pillar thus obtained (the long member 34F for the front pillar after vertical inversion) is as shown in FIG. 11B.

[0075] As shown in Fig. 11C, when machining the left front pillar 13L with respect to the long member 34F for the front pillar after vertical inversion, similar to the case of machining the left front pillar 13L, it is cut at the first cut line 35 below the upper end of the long member 34F for the front pillar to remove the first end piece 36, and cut at the second cut line 37 above the lower end of the long member 34F for the front pillar to remove the second end piece 38.

[0076] Note that the first cut line 35 and the second cut line 37 when machining the right front pillar 13R are equal to those when machining the left front pillar 13L in terms of the inclination direction and the positions from both ends of the long member 34F for the front pillar (positions in the longitudinal direction).

[0077] As shown in Fig. 11D, after removing the first end piece 36 and the second end piece 38, if a mirror mounting portion 33 or the like is mounted at a predetermined position in the upper part of the cut long member 34F for the front pillar, the right front pillar 13R shown in Fig. 11D can be machined.

[0078] Note that in this embodiment, an example of cutting both ends in the longitudinal direction of the long member 34F for the front pillar is given, but the cut at the end may be only at one end in the longitudinal direction. Also, the first cut line 35 and the second cut line 37 may be performed along a cutting line other than a straight line, for example, a curve or a combination of a plurality of curves and straight lines.

[0079] In other words, for the left front pillar 13L and the right front pillar 13R, the curvature and the cross-sectional shape are the same for the portions other than the longitudinal ends where the cuts are made.

[0080] The above-mentioned long member 34F for the front pillar can be machined into both the left front pillar 13L and the right front pillar 13R depending on whether it is inverted in the longitudinal direction before cutting. In other words, the long member 34F for the front pillar is a processing raw material (a common processing raw material for the left front pillar 13L and the right front pillar 13R) that can select the left front pillar 13L and the right front pillar 13R depending on the presence or absence of inversion. Therefore, with a common (same-shaped) raw material, the f If the long member 34F for the front pillar is die-formed or bent, the labor of die-forming and bending can be completed in one step. However, with conventional processing methods, it was necessary to individually process the left front pillar 13L and the right front pillar 13R with separate dies, or to bend them separately, which required a great deal of time and cost for die-forming and bending. Therefore, in the cabin 1 of the present embodiment, by adopting the long member 34F for the front pillar as a processing 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.

[0081] In the above description, the left front pillar 13L, the right front pillar 13R, and the long member 34F for the front pillar were described based on the posture standing upright along the vertical direction, in other words, the posture when attached to the cabin 1. However, the first end piece 36 and the second end piece 38 may be cut, or the attachment of the mirror attachment portion 33 or the like may be performed with the left front pillar 13L, the right front pillar 13R, and the long member 34F for the front pillar in a horizontally oriented state or in an inclined state with respect to the horizontal direction. In this case, the long member 34F for the front pillar may be inverted with the middle in the longitudinal direction as a boundary with the inversion reference line M extending in a direction orthogonal to the longitudinal direction.

[0082] Incidentally, the above-described left front pillar 13L and right front pillar 13R are arc-shaped curved with the same curvature (single curvature) from the upper end to the lower end, and the long member 34F for the front pillar, which is the processing raw material of the left front pillar 13L and the right front pillar 13R, is also formed in an arc shape curved with the same curvature (single curvature) from the upper end to the lower end.

[0083] However, if the long member has symmetry such that the curved state remains the same before and after inversion with respect to the inversion reference line M, it is not necessary for the long member to be curved with the same curvature throughout the entire longitudinal direction. For example, with the inversion reference line M located in the middle of the longitudinal direction as a reference, if the curvature at a position a certain distance away in one direction of the longitudinal direction is equal to the curvature at a position the same distance away in the other direction of the longitudinal direction (a curved state that is line-symmetric with respect to the inversion reference line M), it does not necessarily have to be a single curvature. Examples of such long members include the long members for side beams 34S of the left side beam 18L and the right side beam 18R described above.

[0084] Next, the configurations of the left side beam 18L and the right side beam 18R will be described in detail.

[0085] As shown in FIG. 2, the left side beam 18L is disposed above the left door 27L, and the right side beam 18R is disposed above the right door 27R.

[0086] 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 in the width direction of the cabin 1 and is orthogonal to the width direction.

[0087] The left side beam 18L and the right side beam 18R have the same basic configuration except that their arrangements are opposite left and right. Hereinafter, taking the left side beam 18L as a representative example, the structure of the side beam 18 of the present embodiment will be described.

[0088] FIG. 13 shows a comparison of drawings of the left side beam 18L viewed 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.

[0089] As shown in FIG. 13A, the upper surface of the left side beam 18L has an elongated rectangular appearance that extends substantially linearly in the front-rear direction. Specifically, the upper surface of the left side beam 18L is formed in an arc shape that gently curves such that the middle portion in the front-rear direction bulges inward in the width direction. That is, considering the case when assembled as the cabin 1, the distance along the width direction formed between the middle portion in the front-rear direction of the left side beam 18L and the middle portion in the front-rear direction of the right side beam 18R is shorter than the distance along the width direction formed between the front end of the left side beam 18L and the front end of the right side beam 18R (see FIG. 5).

[0090] On the upper surface of the left side beam 18L, screw holes 80 for attaching the roof 9 are formed at positions slightly rearward from the front end and slightly forward from the rear end.

[0091] FIG. 14 shows a cross-sectional view of the above-described left side beam 18L cut at the middle portion in the front-rear direction along the line D-D in FIG. 13A.

[0092] As shown in FIG. 14, the cross-section of the left side beam 18L is surrounded by three wall portions: an upper wall portion 39, a lower wall portion 44, and a left wall portion (outer wall portion). In other words, the cross-section of the left side beam 18L has a substantially U-shaped or substantially Σ-shaped cross-section that opens toward the indoor side. In principle, no wall portion is provided on the right side surface of the left side beam 18L, but a left first fixing plate 42L is provided slightly rearward from the middle portion in the front-rear direction (see FIG. 13B).

[0093] If the cross-section of the left side beam 18L is formed in a substantially U-shaped or substantially Σ-shaped cross-section, when processing the left side beam 18L, by pressing a processing die against the side surface on the outer side in the width direction and performing press working from the inner side in the width direction, the above-described first outer wall portion 40, connection wall portion 43, and second outer wall portion 41 can be easily processed in one operation. Further, if press working is employed, the left side beam 18L can be easily formed in a substantially linear shape in the front-rear direction or in a shape that bulges in a gentle arc shape inward in the width direction.

[0094] 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 formed as a wall surface that is continuously provided at the outer end portion (outer end) in the width direction of the upper wall portion 39 and stands along the vertical direction, and a second outer wall portion 41 that is disposed more inward in the width direction than the first outer wall portion 40 and is formed to stand along 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.

[0095] The connecting wall portion 43 connects the lower end of the first outer wall portion 40 and the upper end of the second outer wall portion 41 in a substantially horizontal direction. In the case of the left side beam 18L, the connecting wall portion 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 portion 43 is formed in a direction that is inclined slightly upward to the right with respect to the horizontal direction. At the lower end of the second outer wall portion 41, the above-described lower wall portion 44 is disposed so as to extend inward in the width direction.

[0096] As shown in FIG. 13B, the right side surface of the left side beam 18L, that is, the side surface of the left side beam 18L facing inward in the width direction, has an arc-shaped appearance in which the middle portion in the front-rear direction bulges upward. The upper wall portion 39 is disposed at the upper part of the right side surface of the left side beam 18L, and the lower wall portion 44 is disposed at the lower part of the right side surface. The left side beam 18L is open toward the right, and the right end of the upper wall portion 39 and the right end of the lower wall portion 44 are provided at a substantially constant interval in the vertical direction.

[0097] On the right side surface of the left side beam 18L, slightly rearward from the middle portion in the front-rear direction, there is a left first fixing plate 4 There is a 2L provided. The left first fixed plate 42L is a member that vertically connects the right end (inner end in the width direction) of the upper wall portion 39 and the right end (inner end in the width direction) of the lower wall portion 44 (see FIG. 14), and is arranged to partially close the opening of the left side beam 18L that opens inward in the width direction. The left first fixed plate 42L is provided for fixing the left reinforcing member 49L described later, that is, the left reinforcing member 49L that intersects and connects the left rear pillar 14L, the rear beam 16, and the left side beam 18L. By vertically connecting the right end of the upper wall portion 39 and the right end of the lower wall portion 44 with the left first fixed plate 42L, the left side beam 18L becomes less likely to deform, and it becomes possible to increase the load-bearing capacity of the cabin 1.

[0098] At the front end of the right side surface of the left side beam 18L, a first welding auxiliary portion 50 is provided. The first welding auxiliary portion 50 is a plate member that stands along the vertical direction and is attached so as to incline from the left wall portion (outer wall portion) of the left side beam 18L toward the left rear.

[0099] As shown in FIG. 13C, the left side surface of the left side beam 18L, that is, the left side surface of the left side beam 18L facing outward in the width direction, has an arc-shaped appearance in which the middle portion in the front-rear direction bulges upward, similar to the right side surface. A first outer wall portion 40 is provided at the upper part of the left side surface of the left side beam 18L, and a second outer wall portion 41 is provided at the lower part of the left side surface. The length of the first outer wall portion 40 along the front-rear direction is formed longer than that of the second outer wall portion 41. Therefore, the front end of the first outer wall portion 40 protrudes forward more than the front end of the second outer wall portion 41, and the rear end of the first outer wall portion 40 protrudes rearward more than the rear end of the second outer wall portion 41.

[0100] Next, the configuration of the long member 34S for the side beam will be described in detail.

[0101] As shown in FIG. 15, the above-described left side beam 18L and right side beam 18R are formed from a long member 34S for side beams having the same shape that curves upwardly. That is, the original material common to the left side beam 18L and the right side beam 18R is the long member 34S for side beams.

[0102] The long member 34S for side beams is formed such that the curvature in the front and the curvature in the rear are symmetric with respect to the front and rear with an inversion reference line M intersecting at right angles to the front-rear direction (longitudinal direction) in the middle of the front-rear direction.

[0103] Specifically, the curvature of the long member 34S for side beams changes in multiple steps according to the longitudinal position, as compared with the long member 34F for front pillars having an equal curvature over the entire longitudinal direction. In the case of the present embodiment, the curvature of the lower surface of the long member 34S for side beams changes in four steps. For example, in the regions adjacent to the front and rear of the inversion reference line M, the curvature of the lower surface of the long member 34F for front pillars is R1. In the region adjacent to the outside in the width direction of the region having the curvature R1, the curvature becomes R2. In the region adjacent to the outside in the width direction of the region having the curvature R2, the curvature becomes R3. In the region adjacent to the outside in the width direction of the region having the curvature R3, the curvature of the lower surface changes to R4. In this way, the lower surface of the long member 34S for side beams of the present embodiment has a curvature of either R1, R2, R3, or R4.

[0104] That is, in the long member 34S for side beams of the present embodiment, when the distance from the inversion reference line M to the front and the distance from the inversion reference line M to the rear are equal with the inversion reference line M in the front-rear direction as a reference, the curvatures are equal. Also, when the distance from the inversion reference line M to the front or rear changes, the curvature of the lower surface also changes in multiple steps (four steps in the case of the present embodiment). The change in the multiple-step curvature is a change that increases as the distance from the inversion reference line M in the front-rear direction increases. And the multiple-step curvatures are arranged to be symmetrically positioned with respect to the front and rear with the inversion reference line M as a reference. Therefore, even in the long member 34S for side beams, even if it is inverted before and after with the inversion reference line M positioned in the middle in the front-rear direction as a boundary, the shape before and after inversion does not change, similar to the long member 34F for front pillars. It does not transform.

[0105] In the case of this embodiment, the curvature in each region of the long member 34S for side beams is such that the region with curvature R1 has the smallest curvature, followed by the region with curvature R2 having a smaller curvature than the region with curvature R1, and the regions with curvature R3 and curvature R4 having the largest curvature. That is, the region with curvature R1 is formed with a small curvature so as to secure a space with a sufficient volume inside the roof 9 of the cabin 1. On the other hand, in the region with curvature R4, the curvature of the long member 34S for side beams is formed to be close to the curvature of the front pillar 13 so that the side beam 18 and the front pillar 13 are smoothly connected without giving an impression of being bent. By doing so, the front pillar 13 and the side beam 18 are smoothly connected and do not give a bent appearance, so it becomes possible to obtain a cabin 1 with an appearance excellent in design.

[0106] Also, in the long member 34S for side beams of this embodiment, the curvatures R2 and R3 are formed to be smaller than the curvature R1 and larger than the curvature R4. If regions with curvatures R2 and R3 having intermediate values (smaller than R1 and larger than R4) are provided between the region with curvature R1 and the region with curvature R4, the region with curvature R1 and the region with curvature R4 are smoothly connected without giving an impression of being bent, and it becomes possible to obtain a cabin 1 with an appearance excellent in design as in the above-described case.

[0107] When processing the left side beam 18L from the long member 34S for side beams, the first end piece 36 is cut off and removed from the front end of the long member 34S for side beams, and the second end piece 38 is cut off and removed from the rear end. Then, the left first fixing plate 42L and the left first welding auxiliary part 50L are attached to the inner side surface in the width direction of the long member 34S for side beams by means such as welding, and the left side beam 18L can be processed.

[0108] On the other hand, when machining the right side beam 18R from the long member 34S for side beams, the long member 34S for side beams is horizontally rotated 180 degrees while being bent upward, and the front and rear are reversed. With respect to the long member 34S for side beams rotated in this way, similar to the case of machining the left side beam 18L, the first end piece 36 is cut and removed from the front end of the long member 34S for side beams, and the second end piece 38 is cut and removed from the rear end of the long member 34S for side beams. Then, if the right first fixing plate 42R and the second welding auxiliary part 51 are attached to the inner side surface in the width direction of the long member 34S for side beams by means such as welding, the right side beam 18R can be machined.

[0109] In the present embodiment, an example of cutting both ends in the longitudinal direction of the long member 34S for side beams has been given, but the cutting may be performed only at one end in the longitudinal direction.

[0110] That is, the left side beam 18L and the right side beam 18R of the present embodiment are composed of a long member 34S (long member) for side beams having the same shape in portions other than the longitudinal ends.

[0111] The above-mentioned long member 34S for side beams can be machined into both the left side beam 18L and the right side beam 18R depending on whether or not it is rotated (reversed) in the longitudinal direction before cutting. In other words, the long member 34S for side beams is a processing raw material (a common processing raw material for the left side beam 18L and the right side beam 18R) from which the left side beam 18L and the right side beam 18R can be selected depending on whether or not it is reversed. Therefore, if the long member 34S for side beams is molded or bent with one mold, the labor of mold molding and bending can be completed once. However, in the conventional processing method, it was necessary to machine the left side beam 18L and the right side beam 18R with different molds or to bend them separately , a great deal of time and cost were required for the labor of die forming and bending. Therefore, for the cabin 1 of the present embodiment, by adopting the long member 34S for side beams as a common raw material for the left and right frame members, that is, the left side beam 18L and the right side beam 18R, an increase in manufacturing cost can be suppressed.

[0112] Next, the configurations of the left rear pillar 14L and the right rear pillar 14R will be described in detail.

[0113] As shown in FIG. 5, the cabin 1 of the present embodiment includes a rear panel 32 provided behind the driver's seat 6, door panels of the left door 27L and the right door 27R respectively provided on the left and right sides 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 are collectively referred to as the door panel 27.

[0114] 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) passing through the center in the width direction of the cabin 1 and orthogonal to the width direction.

[0115] As shown in FIGS. 16A and 16B, the left rear pillar 14L and the right rear pillar 14R are formed in a vertically long cylindrical shape. The left rear pillar 14L and the right rear pillar 14R are formed in an arc shape such that the central side in the vertical direction protrudes outward from the outside of the vehicle (rearward and in the outward direction in the width direction) compared to the upper and lower ends.

[0116] Speaker stays 86 are provided on the inner peripheral surfaces of the upper parts of the left rear pillar 14L and the right rear pillar 14R. Speakers for voice notification and broadcasting in the driver's seat 6 can be attached to the speaker stays 86.

[0117] At the upper and lower ends of the left rear pillar 14L facing the outside, stay members 81L for hinge fixing are respectively provided. At the upper and lower ends of the right rear pillar 14R, stay members 81R for hinge fixing are respectively provided.

[0118] As shown in FIGS. 1, 3, and 22, below the stay member 81L for hinge fixing provided at the upper end of the left rear pillar 14L, a first door hinge 29L of the left door 27L is provided, and above the stay member 81L for hinge fixing provided at the lower end of the left rear pillar 14L, a second door hinge 30L of the left door 27L is provided. Also, below the stay member 81R for hinge fixing provided at the upper end of the right rear pillar 14R, a first door hinge 29R of the right door 27R is provided, and above the stay member 81R for hinge fixing provided at the lower end of the right rear pillar 14R, a second door hinge 30R of the right door 27R is provided. The first door hinge 29L and the second door hinge 30L of the left door 27L are joined to the stay member 81L for hinge fixing of the left rear pillar 14L by means such as welding. Also, the first door hinge 29R and the second door hinge 30R of the right door 27R are joined to the stay member 81R for hinge fixing of the right rear pillar 14R by means such as welding.

[0119] The left rear pillar 14L and the right rear pillar 14R are formed from a long member 34R for rear pillar having the same shape that curves so as to bulge rearward and outward. That is, the original material common to the left rear pillar 14L and the right rear pillar 14R is the long member 34R for rear pillar. Note that the long member 34R for rear pillar curves with the same curvature in the entire region from the upper end to the lower end, and the curvatures of the upper half and the lower half are symmetric up and down with the midpoint in the vertical direction as the boundary. That is, the long member 34R for rear pillar has the same shape as the long member 34F for front pillar. Here, the detailed configuration of the long member 34R for rear pillar will not be described.

[0120] The long member 34R for the rear pillar curves so as to bulge rearward and outward in the entire region from the upper end to the lower end, and the curvatures of the upper half and the lower half are symmetric with the midpoint in the vertical direction as the boundary. Specifically, the long member 34R for the rear pillar in the present embodiment has the same curvature in the entire region from the upper end to the lower end, and the curvatures of the upper half and the lower half are symmetric with the inversion reference line M passing horizontally through the middle between the upper end and the lower end (the middle of the upper and lower) as the boundary.

[0121] Therefore, the procedure for processing the left rear pillar 14L and the right rear pillar 14R from the long member 34R for the rear pillar is the same as the procedure for processing the left front pillar 13L and the right front pillar 13R from the long member 34F for the front pillar, and the procedure for processing the left side beam 18L and the right side beam 18R from the long member 34S for the side beam. That is, before cutting the longitudinal ends of the long member 34R for the rear pillar, it is selected whether to invert it vertically or not. After that, when cutting the longitudinal ends, it becomes possible to process the left rear pillar 14L from the long member 34R for the rear pillar that is not vertically inverted, and the right rear pillar 14R from the long member 34R for the rear pillar that is vertically inverted. Note that since the procedure for processing the left rear pillar 14L and the right rear pillar 14R from the long member 34R for the rear pillar is almost the same as that for the long member 34F for the front pillar, a detailed description thereof will be omitted.

[0122] By the way, when using the above-described long member as a frame member in contact with the panel end of any one of the front panel 31, the rear panel 32, or the door panel 27, it is preferable that the long member is provided with a weather strip (door seal 46) (see FIG. 17) for the purpose of waterproofing and dustproofing. In particular, it is preferable that the door seal 46 is installed in the frame member in contact with the panel end of the door panel 27 that is opened and closed in accordance with the boarding and alighting of the operator OP. Examples of the frame member where the installation of the door seal 46 is desirable 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 the present embodiment will be described by taking as a representative example the one provided at the panel end (front end) of the door panel 27.

[0123] The door seal 46 provided on the long member of this embodiment seals the panel ends of the left door 27L and the right door 27R respectively. Hereinafter, taking the left door seal 46L that seals the panel end of the left door 27L as a representative example, the door seal 46 of this embodiment will be described.

[0124] As shown in FIG. 17, the left door seal 46L is of a double seal type that seals the inner surface and the end surface of the panel end of the left door 27L respectively, and exhibits high sealing performance by sealing a plurality of surfaces.

[0125] Specifically, the left door seal 46L has a main lip 47 that seals the main seal surface 54 of the long member and a sub lip 48 that seals the sub seal surface 55 of the long member. In the case of this embodiment, the main seal surface 54 is a portion facing the inner surface of the front end of the left door 27L. The sub seal surface 55 is a portion facing the end surface of the front end of the left door 27L described above.

[0126] If the double lip type door seal 46 described above is provided, when water (rain), wind, dust, or sound tries to enter the cabin 1, it is necessary to pass through both the contact portion between the main lip 47 and the main seal surface 54 and the contact portion between the sub lip 48 and the sub seal surface 55. Compared with a single lip seal member, it becomes difficult for water (rain), wind, dust, and sound to reach the inside of the cabin 1. Therefore, the double lip type door seal 46 described above more reliably prevents water (rain), wind, dust, and sound from entering the cabin 1. Also, in the double lip type door seal 46 described above, a space (passage) can be formed between the main lip 47 and the sub lip 48 to guide water (rain), dust, etc. that have entered through the sub lip 48. This space (passage) is arranged along the outer periphery of the left door 27L and the right door 27R, and can guide water (rain), dust, etc. downward. Therefore, it is further suppressed that water (rain), wind, dust, etc. pass through the main lip 47 and enter the cabin 1.

[0127] In the case of the cabin 1 of the present embodiment, since the left door 27L and the right door 27R are configured to rotate horizontally at the front end around the rear end, a double lip type door seal 46 is not 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, a double lip type door seal 46 may be provided between the inner surfaces of the rear ends of the left door 27L and the right door 27R instead of the single lip type seal member.

[0128] Also, 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 in a stepped shape, and a double lip type door seal 46 is provided using the step. Specifically, in the case of the step formed on the left side surface of the left front pillar 13L, a step that is recessed inward in the width direction (a step formed by a third standing wall portion 66 and a second connecting wall 62 described later) is formed at the rear end of the left side surface. By forming such a step, a surface facing outward in the width direction and a surface facing rearward are formed on the left side surface of the left front pillar 13L. 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, if a step is formed inward in the width direction at the rear end of the left side surface of the left front pillar 13L, the main seal surface 54 and the sub-seal surface 55 corresponding to the double lip of the weather strip can be easily formed, and a high sealing performance against the left door 27L can be obtained.

[0129] In addition, a step may be formed in a member other than the left front pillar 13L or the right front pillar 13R to provide a double-lip door seal 46. For example, a step may be formed on the side of the side beam 18 to provide a double-lip door seal 46. 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, a surface facing outward in the width direction and a surface facing downward are formed on the left side surface of the left side beam 18L. 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 toward the inside in the width direction at the lower end of the left side surface of the left side beam 18L, the main seal surface 54 and the sub seal surface 55 corresponding to the double lips of the weather strip can be easily formed, and high sealing performance against the left door 27L can be obtained.

[0130] Furthermore, in this embodiment, an example has been given in which the door seals 46 are provided at the front and upper ends of the left door 27L and the right door 27R. However, for panels that are movable when opened and closed, the door seals 46 may be provided as appropriate for panels other than the door panel 27. For example, in the case where the rear panel 32 is attached so as to be freely opened and closed, a step may be formed at the front end of the rear panel 32, and the formed step may be utilized to provide the double-lip door seal 46.

[0131] 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.

[0132] As described above, the term "irregular cross section" in this specification refers to a shape that, even if it is inverted about any straight line or rotated around any point, the shape before inversion or rotation will not be the same as the shape after inversion or rotation, that is, a shape that does not have any linear symmetry or rotational symmetry. This refers to a shape that is not

[0133] In this specification, a frame member with a "non-regular cross-section" is referred to as a "non-regular pipe". The non-regular pipe of the present invention is a long member used for frame members constituting a cabin 1 of a work machine (such as a tractor 2). The non-regular pipe in the illustrated example is used for the front pillar 13 of the cabin 1, but the use of the non-regular pipe of the present invention is not limited to the front pillar 13, nor is it limited to the cabin 1. For example, the non-regular pipe of the present invention can also be applied to members other than the cabin 1 in a work machine, or members of equipment such as construction machinery used in an industrial field different from the tractor 2.

[0134] Hereinafter, the non-regular cross-section of the front pillar 13 will be described.

[0135] The non-regular cross-section of the left front pillar 13L shown in FIG. 9A is congruent with the non-regular cross-section of the right front pillar 13R shown in FIG. 9B when it is reversed left and right with respect to a vertical reference plane S (a vertical reference plane S passing through the center in the width direction of the cabin 1 and perpendicular to the width direction, refer to FIGS. 4 to 6) passing through the center in the width direction of the cabin 1 and perpendicular to the width direction. Also, for the non-regular cross-section of the right front pillar 13R shown in FIG. 9B, when it is reversed left and right with respect to the symmetric reference plane MS, it becomes congruent with the non-regular cross-section of the left front pillar 13L shown in FIG. 9A. That is, the left front pillar 13L and the right front pillar 13R are in a line-symmetric relationship left and right.

[0136] Hereinafter, except for the points that are line-symmetric with respect to the symmetric reference plane MS, in principle, considering the points where the shape and structure are congruent, the non-regular cross-section of the present invention will be described in detail using the left front pillar 13L as a representative.

[0137] As shown in FIG. 18, in the non-regular cross-section of the left front pillar 13L, the periphery of the central cavity 59 is surrounded without interruption by a plurality of wall portions, and the central cavity 59 is in a sealed state by the plurality of wall portions. There are four wall portions surrounding the periphery of the cavity 59 in the left front pillar 13L, namely, a first wall portion 60, a second wall portion 63, a first connecting wall 61, and a second connecting wall 62.

[0138] The first wall portion 60 constitutes a part of the outer periphery of the deformed pipe. Specifically, in the case of the left front pillar 13L, the first wall portion 60 is located at the left front when viewed from the center Cp of the cavity 59 (the center of the cavity 59 in the present embodiment means the geometric center or the centroid in the mathematics of the deformed cross-section. The same shall apply hereinafter), and is a wall portion corresponding to a wide range from the right front to the left rear 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.

[0139] The second wall portion 63 constitutes a part of the outer periphery of the deformed pipe (a part different from the first wall portion 60). The second wall portion 63 is arranged in a state of facing the first wall portion 60 with the cavity 59 interposed therebetween. In the case of the left front pillar 13L, the second wall portion 63 is formed as a wall portion that bulges so as to protrude rearward and inward when viewed from the center Cp of the cavity 59.

[0140] The first connecting wall 61 connects one end in the width direction of the first wall portion 60 and one end in the width direction 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 and the right end of the second wall portion 63. The first connecting wall 61 is formed so as to protrude outward from the pipe. In the case of the left front pillar 13L, the first connecting wall 61 is formed so as to protrude to the right when viewed from the center Cp of the cavity 59. The first connecting wall 61 is formed such that the inner periphery is in close contact. In the example shown in FIG. 18, the first connecting wall 61 is formed by bending a single pipe wall and bringing the inner peripheral surfaces of one and the other of the folded-back portions into close contact with each other. However, two pipe walls may be overlapped and the inner peripheral surfaces of the respective pipe walls may be joined and brought into close contact with each other by welding or the like.

[0141] The second connecting wall 62 connects the other end in the width direction of the first wall portion 60 and the other end in the width direction 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 and the left end of the second wall portion 63. The second connecting wall 62 is formed so as to protrude outward of the pipe. In the case of the left front pillar 13L, the second connecting wall 62 is formed so as to protrude rearward when viewed from the center Cp of the cavity 59. The second connecting wall 62 is formed so that its inner circumference is in close contact, similar to the first connecting wall 61. That is, similar to the first connecting wall 61, the second connecting wall 62 also bends a single pipe wall and makes the inner circumferential surfaces of one and the other of the folded-back portions in close contact. However, two pipe walls may be overlapped and the inner circumferential surfaces of the respective pipe walls may be joined and made in close contact by welding or the like.

[0142] Next, each wall portion constituting the deformed cross-section of the left front pillar 13L will be described in detail.

[0143] As shown in FIG. 18, the first wall portion 60 is a portion that bulges fan-shaped outward when viewed from the center Cp of the cavity 59 with respect to the center Cp of the cavity 59. Note that the "fan shape" means a figure composed of two line segments extending substantially radially from the center Cp of the cavity 59 and an arc-shaped line segment connecting between the two line segments.

[0144] Specifically, the first wall portion 60 is configured by combining three standing wall portions. The three standing wall portions have a first standing wall portion 64, a second standing wall portion 65, and a third standing wall portion 66.

[0145] The first standing wall portion 64 is a portion that extends along an arc-shaped locus centered on Cp toward P2, which is away from the front of the center Cp to P3. In the case of the left front pillar 13L shown in FIG. 18, the position P2 is located diagonally right front of the center Cp and indicates the front end (right end) of the first standing wall portion 64. The 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. That is, the first standing wall portion 64 covers the range from diagonally right front to the left of the center Cp. A second standing wall portion 65 is connected to the front end (one end) of the first standing wall portion 64, and a third standing wall portion 66 is connected to the rear end (the other end) of the first standing wall portion 64.

[0146] As shown in FIG. 18, the second standing wall portion 65 bends inward from one end in the width direction of the first standing wall portion 64. Specifically, the second standing wall portion 65 is oriented to bend at substantially a right angle with respect 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, the position P2 in FIG. 18 is the front end of the second standing wall portion 65, and the 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 the rear end (position P4).

[0147] As shown in FIG. 18, the third standing wall portion 66 bends inward from the other end in the width direction of the first standing wall portion 64. Specifically, the third standing wall portion 66 is oriented to bend at substantially a right angle with respect to the first standing wall portion 64 at the 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, the position P3 in FIG. 18 is the front end of the third standing wall portion 66, and the 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 the rear end (position P1).

[0148] The first connecting wall 61 connects one end in the width direction of the first wall portion 60 (position P4) and one end in the width direction of the second wall portion 63 (position P5). In the case of the left front pillar 13L, the first connecting wall 61 extends from one end in the width direction of the first wall portion 60 indicated by P4 in FIG. 18 in a direction toward the right and slightly forward, and after being folded back in a direction toward the left and slightly backward at the first folding portion 67, it extends to one end in the width direction of the second wall portion 63 indicated by P5. That is, the first connecting wall 61 is folded so as to project the first folding portion 67 to the right. Also, the inner surface of the portion from the first folding portion 67 to the position P4 of the first connecting wall 61 and the inner surface of the portion from the first folding portion 67 to the position P5 are in close contact with each other.

[0149] In the case of FIG. 18, the first connecting wall 61 does not extend along the right side, but extends in a direction inclined slightly forward to the right. With such a configuration in which the first connecting wall 61 extends in a direction slightly inclined forward, it becomes easier to bring the front surface of the first connecting wall 61 into surface contact in parallel with the left end of the front panel 31 that is curved in an arc shape toward the front, and it becomes possible to firmly support the left end of the front panel 31 with the first connecting wall 61.

[0150] The second connecting wall 62 connects the other end in the width direction of the first wall portion 60 (position P1) and the other end in the width direction of the second wall portion 63 (position P6). In the case of the left front pillar 13L, the second connecting wall 62 extends from the other end in the width direction of the first wall portion 60 indicated by P1 in FIG. 18 toward the rear, and after being folded back in a direction toward the front at the second folding portion 68, it extends to the other end in the width direction of the second wall portion 63 indicated by P6. That is, the second connecting wall 62 is folded so as to project the second folding portion 68 to the rear. Also, the inner surface of the portion from the second folding portion 68 to the position P1 of the second connecting wall 62 and the inner surface of the portion from the second folding portion 68 to the position P6 are in close contact with each other.

[0151] In the case of FIG. 18, the second connecting wall 62 extends rearward from the right end of the third standing wall portion 66 and is arranged parallel to the inner surface of the left door 27L so as to be easily brought into surface contact with the left door 27L. By aligning the forming direction of the second connecting wall 62 with the orientation direction of the inner surface of the left door 27L in this way, it becomes possible to seal the second connecting wall 62 and the left door 27L airtightly and watertightly using a door seal 46 described later.

[0152] Note that the first wall portion 60 and the second connecting wall 62 described above are formed to project in directions orthogonal 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. Since 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 orthogonal to each other.

[0153] The second wall portion 63 is arranged to face the first standing wall portion 64 of the first wall portion 60 with the cavity 59 interposed therebetween. The second wall portion 63 connects the rear end of the first connecting wall 61 indicated by P5 and the right end of the second connecting wall 62 indicated by P6 in FIG. 18. 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 a folded line shape that protrudes outward.

[0154] An outer fold 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 outer fold portion 70 is located outside P5 and P6 when viewed from the center Cp of the cavity. In other words, in the second wall portion 63 of the second embodiment, the outer fold portion 70 is formed in a state of protruding outside the cavity 59 when viewed from the center Cp of the cavity 59.

[0155] The second wall portion 63 between the outer fold portion 70 and P5 is formed in a straight line, and the second wall portion 63 between the outer fold portion 70 and P6 is also formed in a straight line. And with the outer fold portion 70 as a reference, one second wall portion 63 and the other second wall portion 63 are formed with different inclinations.

[0156] In the present embodiment, an example is given in which the first connecting wall 61 and the second connecting wall 62 are formed by folding a single plate material in a folded-back manner and connected. However, two separately formed plate materials joined so that their inner surfaces are in close contact with each other may be used for the first connecting wall 61 and the second connecting wall 62.

[0157] In the second wall portion 63 of the second embodiment, the outward bent portion 70 protrudes outward from the center Cp of the cavity 59 when viewed from the center Cp of the cavity 59, as compared with the rear end (P5) of the first connecting wall 61 and the right end (P6) of the second connecting wall 62. That is, the outward bent portion 70 is formed as a protruding ridge portion 71. In other words, the outward bent portion 70 is the "ridge portion 71 that protrudes most outward from the pipe". Further, the rear end (P5) of the first connecting wall 61 and the right end (P6) of the second connecting wall 62 are formed as valley portions 72 that are recessed inward from the center Cp of the cavity 59 as compared with the outward bent portion 70. In other words, P5 is the "contact point between the first connecting wall 61 and the second wall portion 63", P6 is the "contact point between the second connecting wall 62 and the second wall portion 63", and a "valley portion 72 that is recessed inward from the pipe more than the ridge portion 71" is formed at P5 and P6.

[0158] If such a ridge portion 71 and valley portion 72 are provided on the second wall portion 63, when a plurality of pipes such as electrical wiring, drain hoses, and refrigerant pipes are arranged outside the left front pillar 13L, the pipes are arranged in a state where they are naturally separated from each other with the ridge portion 71 as a boundary (see pipes H 1、 H3), and it becomes possible to prevent troubles such as the pipes getting entangled with each other.

[0159] Note that the second wall portion 63 includes a flat surface that extends in a direction parallel to a tangent line passing through a point on the outer surface of the first wall portion 60 between the valley portion 72 and the ridge portion 71. Specifically, this "flat surface" is a straight portion of the second wall portion 63 provided between the ridge portion 71 and the position P6, and there is a position P7 on the first wall portion 60 where a tangent line L T is provided in a direction parallel to the second wall portion 63. That is, the second wall portion 63 has a flat surface parallel to the tangent line L T of the arc surface of the first standing wall portion 64.

[0160] The tangent line L passing through a point P7 on the outer surface of the above-described first wall portion 60 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 orthogonal to the flat surface (the tangent line L

[0161] FIG. 19A shows a deformed cross-section of the present embodiment, and the cross-section of FIG. 19B is not a deformed cross-section of the present embodiment but a cross-section of a conventional example. That is, in the cross-section of FIG. 19A, the inner periphery of the first connection portion 361 is not formed in close contact, and the inner periphery of the second connection portion 362 is not formed in close contact either.

[0162] In the cross-section of the conventional deformed pipe (conventional left front pillar 313L) shown in FIG. 19B, it can be seen that the second wall portion 363 projects the outer bending portion 370 outward from the center Cp' of the cavity. However, in the conventional cross-section, since the second wall portion 363 projects largely outward, the protruding second wall portion 363 gets in the way and it is not possible to sufficiently secure a space for arranging pipes (see FIG. 18). Therefore, in the conventional cross-section, there were cases where pipes such as electrical wiring, drain hoses, and refrigerant pipes could not be arranged rearward.

[0163] In addition, when pipes H1 to H3 are forcibly arranged behind the protruding second wall portion 163 with respect to the conventional cross section, it is necessary to largely protrude a cover (not shown) that conceals the pipes H1 to H3 also rearward. Then, the width of the left front pillar 113L along the front-rear direction and the left-right direction (width direction) becomes wider by the amount of the cover protruding rearward (inward). That is, in a conventional cabin in which the left front pillar 113L is widened in the front-rear direction, the opening width of the entrance / exit of the cabin becomes narrower by the amount of the left front pillar 113L being widened in the front-rear direction, and the ingress / egress performance of the cabin deteriorates. Further, in a conventional cabin in which the left front pillar 113L is widened in the left-right direction, the view of the front panel becomes narrower in the left-right direction by the amount of the left front pillar 113L being widened in the left-right direction, and the forward visibility from the cabin also easily deteriorates.

[0164] On the other hand, in the deformed cross section of the present embodiment shown in FIG. 19A, since the protrusion of the second wall portion 63 toward the outside (rear) is suppressed, a sufficient space can be secured for arranging the pipes H1 to H3 outside the second wall portion 63. Further, even when the pipes H1 to H3 are arranged and then concealed with the cover 73, the outward protrusion of the cover 73 can be suppressed.

[0165] 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 disposed outside the outer folding portion 70 (ridge portion 71), a space can be secured between the cover 73 and the second wall portion 63 where pipes H1 to H3 can be arranged. Specifically, the cover 73 includes a first cover wall 73a that extends rearward from an end portion that protrudes outward of the pipe in the first connection wall 61, a second cover wall 73b that extends inward in the width direction from an end portion that protrudes outward of the pipe in the second connection wall 62, and a third cover wall 73c that connects the first cover wall 73a and the second cover wall 73b. The first cover wall 73a is located outward in the width direction from the forward visibility boundary line FL that connects the center of the driver's seat 6 and the end portion that protrudes outward of the pipe in the first connection wall 61. Also, the second cover wall 73b is located forward of the side visibility boundary line SL that connects the center of the driver's seat 6 and the second folding portion 68. Therefore, even when the cover 73 is provided, the first cover wall 73a of the cover 73 does not protrude so as to block the forward visibility. Also, the second cover wall 73b of the cover 73 does not protrude so as to block the left boarding and alighting opening 28L, and does not narrow the opening width of the left boarding and alighting opening 28L of the cabin 1. That is, the cover 73 does not narrow the opening width of the boarding and alighting openings of the cabin 1 or narrow the field of view of the front panel 31. Therefore, the width along the front-rear direction and the width along the left-right direction of the left front pillar 13L as viewed from the driver's seat 6 can be maintained in a wide state, and the boarding and alighting performance and visibility of the cabin 1 can be improved.

[0166] In addition, as examples of the "second wall portion 63 being recessed toward the cavity 59" with a deformed cross-section, in addition to those shown in Fig. 18 and Fig. 19A, the examples shown in Fig. 20A and Fig. 20B can also be cited.

[0167] The deformed cross-section shown in Fig. 20A shows an example in which the close contact range of the inner circumference in the first connection wall 61 is taken wider than the deformed cross-section of the present embodiment shown in Fig. 19A. Compared with the deformed cross-section shown in Fig. 18, the space that can be secured behind the second wall portion 63 becomes larger, but the bending strength of the front pillar 13 is slightly lower by the amount that the cross-sectional area of the deformed cross-section becomes smaller.

[0168] In addition, the deformed cross-section shown in Fig. 20B is an example (an example in which the inner circumferences of two plate materials are in close contact) formed by superposing two plate materials in which the first connecting wall 61 and the second connecting wall 62 are formed separately. That is, the deformed pipe shown in Figs. 20A and 20B is formed from two plate materials. Specifically, the deformed pipe shown in Fig. 20A is formed by joining, by welding or the like, one plate material constituting the first wall portion 60, a part of the first connecting wall 61, and a part of the second connecting wall 62, and one plate material constituting the second wall portion 63, the remaining part of the first connecting wall 61, and the remaining part of the second connecting wall 62. Even in the deformed cross-section shown in Fig. 20B, while maintaining the bending strength of the front pillar 13, it is possible to secure a space in which the pipes H1 to H3 can be arranged, and to improve the boarding and alighting properties and visibility of the cabin 1.

[0169] The deformed pipe having the deformed cross-section described above can be used not only for the front pillar 13 but also for various types of frame materials. Since the configuration of the deformed pipe is the same as that of the left front pillar 13L having the deformed cross-section described above, the description thereof is omitted.

[0170] In the cabin 1 of the present embodiment, in preparation for the case where a large load is applied to the front pillar 13, measures such as adopting a frame material having the deformed cross-section as described above for the front pillar 13 are taken to increase the load-bearing capacity of the front pillar 13. However, considering safety when the work machine overturns or the like, it is preferable not only to support the load applied to the cabin 1 only by the front pillar 13 but also to reinforce the side beam 18 connected to the front pillar 13 to improve the overall load-bearing capacity of the cabin 1. Therefore, in the cabin 1 of the present embodiment, a reinforcing member 49 is provided at the upper part of the rear pillar 14.

[0171] Next, the reinforcing member 49 provided in the cabin 1 of the present embodiment will be described.

[0172] As shown in FIGS. 7, 21, and 22, the reinforcing member 49 provided at the upper portion of the rear pillar 14 connects the rear beam (rear beam 16) and the side beam 18 in a crosswise manner through the interior side of the rear pillar 14. The reinforcing member 49 is a plate member bent in a substantially 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) is fixed to the rear beam 16, and the central portion in the front-rear direction is fixed to the upper portion of the rear pillar 14, respectively, using means such as welding. That is, the reinforcing member 49 connects the three members of the rear beam 16, the upper portion of the rear pillar 14, and the side beam 18, thereby supporting the side beam 18 with respect to the rear beam 16 and the upper portion of the rear pillar 14.

[0173] Note that the reinforcing member 49 of the present embodiment includes a left reinforcing member 49L provided at the upper portion of the left rear pillar 14L and a right reinforcing member 49R provided at the upper portion of the right rear pillar 14R. The left reinforcing member 49L and the right reinforcing member 49R have a symmetric structure in the left-right direction, and their basic structures are the same except for the symmetric points in the left-right direction. Therefore, hereinafter, the right reinforcing member 49R provided at the upper portion of the right rear pillar 14R will be taken as an example to explain the reinforcing member 49 of the present invention.

[0174] First, the rear beam 16 to which the right reinforcing member 49R is connected will be described in detail.

[0175] As shown in FIGS. 2 and 6, the rear beam 16 is a frame member that connects the upper portions of the left rear pillar 14L and the right rear pillar 14R in the left-right direction. Different from the front beam 15, the rear beam 16 is not curved upward and is formed to extend linearly in the left-right direction.

[0176] As shown in FIG. 7, the rear beam 16 is a frame member having a substantially U-shaped cross section that opens forward (a shape in which only the front side is removed from a quadrilateral having sides in the vertical, front, and rear directions, and the three sides of the upper side, rear side, and bottom side are left, an angular U shape). On the left side of the rear beam 16, a left second fixing plate 83L that connects openings opening forward in the vertical direction is provided. Also, on the right side of the rear beam 16, a right second fixing plate 83R that connects the openings in the vertical direction is provided. The distance from the left end of the rear beam 16 to the left second fixing plate 83L is equal to the distance from the right end of the rear beam 16 to the right second fixing plate 83R. Further, the upper and lower edges of the left second fixing plate 83L and the right second fixing plate 83R are joined to the openings of the rear beam 16 by means such as welding.

[0177] As shown in FIGS. 13A to 13C, the first fixing plate 42 is provided for fixing 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 so as to extend in the front-rear direction. The first fixing plate 42 has a left first fixing plate 42L for fixing the left reinforcing member 49L and a right first fixing plate 42R for fixing 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. The front end (left first connection portion 82L, which will be described later) of the left reinforcing member 49L is joined to a midway portion in the vertical direction of the left first fixing plate 42L. Also, the front end (right first connection portion 82R, which will be described later) of the right reinforcing member 49R is joined to a midway portion in the vertical direction of the right first fixing plate 42R. By joining the front ends of the left reinforcing member 49L and the right reinforcing member 49R to a midway portion in the vertical direction of the right first fixing plate 42R, it becomes difficult for spatter debris generated during welding to adhere to the upper surface of the upper wall portion 39, and it becomes possible to enhance the sealing performance of the door seal 46.

[0178] Note that, in this embodiment, welding is used as the means for joining the front end of the reinforcing member 49 to the first fixing plate 42, but brazing, screwing, adhesive, etc. may also be used.

[0179] Next, the right reinforcing member 49R will be described in detail.

[0180] The front end (front part) of the right reinforcing member 49R is connected to the vicinity of the center in the front-rear direction of the right side beam 18R, specifically to the right first fixing plate 42R in this embodiment. That is, the front end of the right reinforcing member 49R is the right first connection portion 82R that connects the right reinforcing member 49R to the right side beam 18R. Also, the right end (right part) of the right reinforcing member 49R is connected to the right part of the rear beam 16, specifically to the right second fixing plate 83R in this embodiment. That is, the right end (right part) of the right reinforcing member 49R is the right second connection portion 84R that connects the right reinforcing member 49R to the right part of the rear beam 16.

[0181] The right reinforcing member 49R has a central base portion 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 edge facing the right rear of the central base portion 85 is joined to the outer peripheral surface on the interior side of the right rear pillar 14R. Specifically, the edge facing the right rear of the central base portion 85 (the edge facing the outside) is in direct contact with the outer peripheral surface on the interior side of the right rear pillar 14R, and the contact portion is joined by welding. Note that the joining of the central base portion 85 is not limited to the above-described direct joining. That is, 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 protruding toward the interior side, and is provided with a speaker mounting hole 87 for fitting a speaker on the surface facing the interior side. The above-described central base portion 85 is arranged in a state of being placed on the box-shaped speaker stay 86, and the lower surface of the central base portion 85 and the upper end of the speaker stay 86 are joined by means such as welding. That is, the right reinforcing member 49R is also joined to the outer peripheral surface on the interior side of the right rear pillar 14R by an indirect joining means via the speaker stay 86. By using such two types of joining, the right reinforcing member 49R is firmly joined to the upper part of the right rear pillar 14R.

[0182] Incidentally, the right first fixing plate 42R is provided near the central portion in the front-rear direction of the right side beam 18R. This "near the central portion" means not only the central portion in the front-rear direction of the right side beam 18R, but also slightly behind or in front of the central portion. Specifically, with the central portion in the front-rear direction as a reference, a position shifted backward or forward by about 20% of the total length along the front-rear direction of the right side beam 18R is also included in the "near the central portion".

[0183] Also, the above-described right first connecting portion 82R is provided at the vertical middle of the right first fixing plate 42R, and the right second connecting portion 84R is provided at the vertical middle of the right second fixing plate 83R. That is, the right first connecting portion 82R is disposed below the upper surface of the right side beam 18R, and the right second fixing plate 83R is disposed below the upper surface of the right portion of the rear beam 16. If the right first connecting portion 82R is formed at a distance below the upper surface of the right side beam 18R in this way, spatter slag or the like generated when joining the right first connecting portion 82R to the right first fixing 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 amount of the distance in the vertical direction. Also, if the right second connecting portion 84R is formed at a distance below the upper surface of the right portion of the rear beam 16, spatter slag or the like generated when joining the right second connecting 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.

[0184] 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 FIG. 21, if the distance between the right first connecting portion 82R and the central base portion 85 is L1, and the distance between the right second connecting portion 84R and the central base portion 85 is L2, the relationship L1 > L2 holds.

[0185] Note that the distance L1 precisely means the length along the front-rear direction of a straight 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 portion 85. Further, the distance L2 means the length along the left-right direction of a straight 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 portion 85.

[0186] If the distance L1 is made larger than the distance L2, the right first connection portion 82R of the right reinforcing member 49R can support the right side beam 18R more forward, and the deformation resistance (the deformation resistance when the cabin 1 is deformed along the left-right direction) at the front portion of the cabin 1 can be increased. That is, the cabin 1 of the present embodiment can not only increase the strength of the rear portion of the cabin frame 8, but also increase the strength of the front portion by providing the right reinforcing member 49R having a shape such that the distance L1 is larger than the distance L2. As a result, in the cabin 1 of the present embodiment, it is possible to suppress deformation and breakage of the cabin 1 even when a rollover or the like occurs, and it is possible to further improve the safety as compared with a conventional cabin.

[0187] Next, the roof seal 45 will be described in detail.

[0188] The roof seal 45 is a member that seals between the upper surfaces of the four frame members provided on the upper portion of the cabin 1, that is, the front beam 15, the left side beam 18L, the right side beam 18R, and the rear beam 16, and the roof 9.

[0189] As shown in FIG. 7, the roof seal 45 is continuously arranged so as to circulate 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 through the upper portion of the reinforcing member 49 provided on the upper portion of the rear pillar 14, it is arranged so as to pass through the indoor side of the rear pillar 14.

[0190] When the roof seal 45 (the portion indicated by A in FIG. 7) passing through the upper portion of the reinforcing member 49 is enlarged, it becomes as shown in FIG. 21.

[0191] As shown in FIG. 21, a roof seal surface 88 on which a 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.

[0192] Note that the black dots in the figure mean that the portions indicated by the reference numerals including the peripheries of the black dots. For example, the black dot to which the reference numeral 89 is attached means that the area including the periphery of the black dot is the first seal surface 89.

[0193] The first seal surface 89 is a portion of the upper surface of the right reinforcing member 49R that is adjacent inward (indoorside) to the upper surface 18Re of the rear portion of the right side beam 18R. The first seal 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 disposed rearward along the upper surface of the right side beam 18R can be guided (arranged) from the upper surface 18Re to the first seal surface 89 without changing the height.

[0194] The second seal surface 90 is a portion of the upper surface of the right reinforcing member 49R that is adjacent forward to the upper surface 16Re of the right portion of the rear beam 16. The second seal surface 90 is formed at substantially 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 disposed rightward along the upper surface 16Re of the rear beam 16 can be guided (arranged) from the upper surface 16Re to the second seal surface 90 without changing the height.

[0195] The third sealing surface 91 is formed between the first sealing surface 89 and the second sealing surface 90, and is also formed as the upper surface of the central base portion 85. The third sealing surface 91 does not have to be at the same height as the first sealing surface 89 or the second sealing surface 90. The third sealing surface 91 of the present embodiment is also disposed at a position slightly lower than the first sealing surface 89 and the second sealing surface 90. However, the third sealing surface 91 needs to be continuous with the first sealing surface 89 and the second sealing surface 90. Therefore, between the third sealing surface 91 and the first sealing surface 89 of the present embodiment, or between the third sealing surface 91 and the second sealing surface 90 of the present embodiment, a gentle slope connecting two surfaces with different heights is formed. If the third sealing surface 91 is formed as a continuous surface with respect to the first sealing surface 89 and the second sealing surface 90, the roof seal 45 can be guided (arranged) from the first sealing surface 89 to the second sealing surface 90 without suddenly changing the height up and down.

[0196] That is, if the roof seal surface 88 including the first sealing surface 89, the second sealing surface 90, and the third sealing surface 91 described above 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 arranged to pass through the indoor side of the rear pillar 14 without suddenly changing the height up and down. That is, the roof seal 45 composed of an elastic member can perform sealing by deforming itself even if there is a slight step up and down. However, when the step up and down becomes large, it becomes impossible to cover the step only by deforming itself, and it becomes difficult to perform sufficient sealing. In particular, in a conventional cabin, there is one in which the height of the rear beam is lower than that of the right side beam 18R. In such a conventional cabin, the sealing member may be interrupted around the rear beam, and sufficient sealing performance may not be exhibited. However, in the cabin 1 of the present embodiment using the right reinforcing member 49R having the roof seal surface 88, the roof seal 45 can be disposed without interruption, and sufficient sealing performance can be exhibited.

[0197] The above-described reinforcing member 49 was provided at the upper part of the rear pillar 14 and connected the end of the rear beam 16 and the rear end of the side beam 18, thereby enhancing the load-bearing capacity of the cabin 1. However, in the cabin 1 of the present embodiment, not only the reinforcing member 49 at the upper part of the rear pillar 14 but also front reinforcing means for enhancing the load-bearing capacity of the cabin 1 is provided at the upper part of the front pillar 13. There are two front reinforcing means, one provided at the upper part of the left front pillar 13L and the other provided at the upper part of the right front pillar 13R.

[0198] Hereinafter, the front reinforcing means of the present embodiment will be described by taking as an example the front reinforcing means provided at the upper part of the right front pillar 13R.

[0199] As shown in FIG. 23, the front reinforcing means provided at the upper part of the right front pillar 13R includes a right first welding auxiliary part 50R provided at the front part of the right side beam 18R and a right second welding auxiliary part 51R provided at the right end of the front beam 15. The right first welding auxiliary part 50R is a plate member extending from the front end of the right side beam 18R inward and rearward. The right first welding auxiliary part 50R is joined to the lower surface of the upper wall part 39, the upper surface of the lower wall part 44, and the inner surface of the side wall part of the right side beam 18R by means such as welding. The right second welding auxiliary part 51R is a plate material bent in a substantially L shape when viewed from above and is joined to the right end of the lower wall part 15b of the front beam 15. The right end of the right second welding auxiliary part 51R is oriented in a direction substantially orthogonal to the right first welding auxiliary part 50R, and T-joint welding can be performed on the surface of the right first welding auxiliary part 50R.

[0200] If the right first welding auxiliary part 50R and the right end of the right second welding auxiliary part 51R can be joined by T-joint welding, the area of the welding portion becomes wider compared to normal butting welding, and it becomes possible to firmly join the front part of the right side beam 18R and the right end of the front beam 15.

[0201] Next, the support structure 99 of the front panel 31 provided in the cabin 1 of the present embodiment will be described.

[0202] FIG. 24 is an enlarged rear view of the support structure 99 as seen from the rear (driver's seat 6). In FIG. 24, since the brake pedal 97, the steering column 121, the interlock release pedal 124, etc. get in the way and the structure of the front part of the support structure 99 is difficult to see, an enlarged rear view of the support structure when the brake pedal, the steering column, the interlock release pedal, etc. are removed is also shown in FIG. 25. FIG. 26 is an enlarged front view of the support structure as seen from the front. Further, FIG. 27 is a cross-sectional view of the support structure 99 cut along the front-rear direction in the middle of the left-right direction.

[0203] As shown in FIGS. 24 to 27, the cab 1 of the present 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 arranged outward in the width direction, and supports the front panel 31 from below.

[0204] Specifically, as shown in FIGS. 25 and 26, the front panel 31 of the present embodiment is formed as a single plate having a notch 100 at the center in the width direction at the lower end. The notch 100 of the present embodiment is formed in a square shape recessed upward at the center in the width direction of the front panel 31.

[0205] As shown in FIGS. 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 on the step 23 in front of the driver's seat 6. The panel support frame 95 has an opening frame 102 standing in the vertical direction along the front panel 31, and a base frame 103 provided connected to the rear of the periphery of the opening frame 102. The support structure 99 includes a pedal support portion 98 that supports the brake pedal 97 with respect to the panel support frame 95. The pedal support portion 98 of the present embodiment has a support shaft 101 that swingably supports the brake pedal 97.

[0206] Next, the panel support frame 95 and the pedal support portion 98 that constitute the support structure 99 will be described.

[0207] First, the front panel 31 supported by the support structure 99 will be described.

[0208] As shown in FIGS. 5 and 25, the front panel 31 is formed of a panel having light transmissibility, and its upper end, left end, and right end 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 surface shape that bulges forward. A notch portion 100 is formed at the lower end in the width direction center of the front panel 31.

[0209] The notch portion 100 is a portion that is cut out in a square shape and formed at the lower edge in the width direction center of the front panel 31. The notch portion 100 is formed in a horizontally long square shape when viewed from the front and opens downward.

[0210] The panel support frame 95 is disposed behind the notch portion 100 and is a member that enables the front panel 31 to 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 and provided behind the peripheral edge of the opening frame 102.

[0211] The opening frame 102 is an upright plate member and is formed in a gate shape (a shape like the upper half when a substantially square frame is bisected vertically), so as to follow the opening shape of the notch 100 of the front panel 31. In other words, the opening frame 102 has a horizontally long rectangular opening when viewed from the front, corresponding to the opening shape of the notch 100. Further, the opening of the opening frame 102 is surrounded by 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, the left opening edge 102a, the right opening edge 102b, and the upper opening edge 102c have a predetermined thickness outward, and are configured as a single plate member that is continuous so as to surround the periphery of the opening. The opening frame 102 is attached to the front panel 31 around the notch 100 using an adhesive or a fastener or the like, and is capable of supporting from below a part of the weight of the front panel 31, the roof 9, and further the air conditioners provided in the roof 9.

[0212] Note that what is supported by the opening frame 102 is only a part of the weight of the front panel 31, the roof 9, and further the air conditioners provided in the roof 9. That is, in the cabin 1 of the present embodiment, left front pillars 13L and right front pillars 13R that support the front panel 31 are respectively arranged at the left and right ends of the front panel 31. Further, at the upper end of the front panel 31, and at the upper ends of the left front pillar 13L and the right front pillar 13R, a front beam 15 that curves upward in a protruding shape is provided. Therefore, the weight of the roof 9 arranged above the driver's seat 6 and the air conditioners provided in 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 formed 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, a part of the weight of the roof 9 and a 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. That is, although the part of the weight of the front panel 31, the roof 9, and the air conditioners provided in the roof 9 has a smaller weight share compared to the left front pillar 13L and the right front pillar 13R, it is still supported by the front panel 31.

[0213] The base frame 103 is a frame member in the shape of a triangular prism that is horizontally laid adjacent to the rear of the opening frame 102. The base frame 103 is provided connected to the peripheral edge of the opening of the opening frame 102, that is, the left opening edge 102a, the right opening edge 102b, and the upper opening edge 102c.

[0214] 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 that are respectively connected to the left opening edge 102a, the right opening edge 102b, and the upper opening edge 102c of the opening frame 102.

[0215] The left base frame side wall 103a is connected behind the left opening edge 102a of the opening frame 102, and the right base frame side wall 103b is connected behind the right opening edge 102b of the opening frame 102. Both the left base frame side wall 103a and the right base frame side wall 103b are formed in a triangular shape such that the vertical height decreases toward the rear when viewed from the side.

[0216] The frame plate 106 is a plate member having a square shape when viewed from above, and is connected behind the upper opening edge 102c of the opening frame 102. The frame plate 106 is inclined so as to shift upward (so as to descend toward the rear) as it goes from the rear toward the upper part of the opening frame 102. On the left and right of the frame plate 106, a left through portion 106a and a right through portion 106b that penetrate the frame plate 106 and communicate with the inside and outside of the cabin 1 are formed. 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. A through hole 105 through which a steering shaft 104 extending from the front of the driver's seat 6 toward the front lower side penetrates is formed in the right closing plate 116b that closes the right through portion 106b, and a bellows-type boot portion 117 is attached to the through hole 105.

[0217] The support structure 99 not only has a function of supporting the front panel 31, but also has a 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 with respect to the panel support frame 95 in order to support the brake pedal 97 (or the clutch member 115 in some cases).

[0218] The pedal support portion 98 has a support portion main body 118 assembled in a lattice shape above the panel support frame 95, a support frame 119 that supports the support portion main body 118 with respect to the panel support frame 95, and a support shaft 101 that swingably supports the brake pedal 97.

[0219] As shown in FIG. 25, the support frame 119 includes five frames. The five frames provided on the support frame 119 are the left first frame 108, the left second frame 109, the central frame 110, the right first frame 111, and the right second frame 112. The left first frame 108 supports the left end of the support shaft 101 with respect to the left end of the base frame 103. The left second frame 109 supports the left end of the opening frame 102 with respect to the left first frame 108. The central frame 110 supports the midpoint in the horizontal direction of the support shaft 101 with respect to the central portion of the base frame 103. The right first frame 111 supports the central frame 110 and the right end of the support shaft 101 with respect to the right end of the base frame 103. The right second frame 112 supports the right end of the opening frame 102 with respect to the right first frame 111. By performing support using the support frame 119 composed of these five frames, it becomes possible to firmly support the support portion main body 118 at a position separated upward from the base frame 103 (panel support frame 95).

[0220] The support portion main body 118 is a cylindrical member arranged along the horizontal direction, and is fixed so as to span horizontally the upper ends of the left first frame 108, the central frame 110, and the right first frame 111 among the support frames 119. The support portion main body 118 can be fixed so that the support shaft 101 is oriented horizontally with its axis inserted into the inside formed in a cylindrical shape.

[0221] On the right side of the support part main body 118, a steering column 121 that rotatably supports the steering shaft 104 is attached. The steering column 121 is a cylindrical member that stands upright in an inclined manner from the front lower side to the rear upper side. Two steering shafts 104 are provided vertically, and the upper steering shaft 104a and the lower steering shaft 104b are connected via a universal joint so as to be able to transmit the steering operation. The upper steering shaft 104a penetrates through the inside of the steering column 121 rotatably with respect to the steering column 121. A steering wheel is attached to the upper end of the upper steering shaft 104a, and the rotational operation of the steering wheel can be transmitted to the rotational operation of the upper steering shaft 104a. Also, the lower steering shaft 104b is connected to the lower end of the upper steering shaft 104a. The lower steering shaft 104b penetrates through a through hole 105 formed in the right closing plate 116b of the frame plate 106 and protrudes outside the cabin 1.

[0222] Below the support part main body 118, a connecting and reinforcing frame 113 is provided. The connecting and reinforcing frame 113 is a plate member with a rectangular cross-section in which the middle side in the vertical direction protrudes forward with respect to the upper and lower ends. The connecting and reinforcing frame 113 is fixed to the lower part of the support part main body 118 using means such as welding. Also, the connecting and reinforcing frame 113 is joined in a state where three members, namely the left first frame 108, the center frame 110, and the right first frame 111, are connected in the left-right direction and by connecting and integrating each member, the support strength of the support structure 99 is increased.

[0223] The support shaft 101 is a bar that is longer in the horizontal direction than the support body 118, and both the 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, on the support shaft 101, 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 are formed. A brake pedal 97 is rotatably attached to the left end 101a of the support shaft 101 around an axis facing the horizontal direction. Although not shown in the figure, in the case of a tractor 2 (working machine) provided with a clutch, a clutch member may be further provided at the left end 101a of the support shaft 101.

[0224] In the case of this embodiment, two brake pedals 97 are provided side - by - side in the left - right direction at the left end 101a of the support shaft 101. That is, the brake pedal 97 includes 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 performing a stop operation of the left rear wheel 12L. The right brake pedal 97R is a brake for performing a stop operation of the right rear wheel 12R. The left brake pedal 97L includes a left pedal arm 122L whose base end is rotatably supported by 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 to return to the depressed initial position. Also, the right brake pedal 97R includes a right pedal arm 122R whose base end is rotatably supported by 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 to return to the depressed initial position.

[0225] Between the left pedal plate 123L and the right pedal plate 123R, an interlocking member 114 is provided which enables the left and right brakes to be simultaneously depressed or released by connecting the two members. The interlocking member 114 is an electromagnetic or hydraulic type for connecting the left pedal plate 123L and the right pedal plate 123R, and by connecting the left pedal plate 123L and the right pedal plate 123R, the left and right brakes are put into an interlocked state. The release of the interlock for the interlocking member 114 is performed by the interlock release pedal 124.

[0226] The interlock release pedal 124 is a pedal for releasing the interlock by the interlocking member 114, and is provided on either the left or right side of the support structure 99. In this embodiment, since the interlock release pedal 124 is disposed substantially at the center of the support structure 99, the five frames constituting the support frame 119 may remain straight (no need to bend). However, when the interlock release pedal 124 is provided on the left of the support structure 99, the left first frame 108 and the left second frame 109, which are the frames on the side where the interlock release pedal 124 is provided, that is, on the left of the support structure 99, may be formed such that the middle side in the vertical direction bends inward in the horizontal direction. Further, when the interlock release pedal 124 is provided on the right of the support structure 99, the right first frame 111 and the right second frame 112, which are provided on the right side where the interlock release pedal 124 is provided, may be formed such that the middle side in the vertical direction bends inward in the horizontal direction. The example shown in FIG. 24 is such that the middle side in the vertical direction of the right first frame 111 and the right second frame 112 bends leftward, and can be suitably used when the interlock release pedal 124 is provided on the right of the support structure 99.

[0227] In addition, even when the clutch member is provided on the left of the support structure 99, the middle side in the vertical direction of the left frames (left first frame 108 and left second frame 109) of the pedal support portion 98 can be bent rightward.

[0228] In the case of such a cabin 1, even if there are members such as the interlock release pedal 124 and the clutch member on the left and right sides of the support structure 99, when stepping on the interlock release pedal 124, the clutch member, etc., the frame of the pedal support portion 98 will not get in the way, and the interlock release and the operation of the clutch member can be surely performed.

[0229] By the way, in the cabin 1 of the present embodiment, the height of the opening frame 102 provided in the panel support frame 95 is lowered, and the notch portion 100 with respect to the front panel 31 is suppressed to be low and have a small area. If the notch portion 100 is suppressed to be low and have a small area in this way, the view of the front panel 31 can be widened, and the visibility from the cabin 1 can be improved. Further, if the notch portion 100 is made small, the labor of cutting the front panel 31 is reduced, and breakage is less likely to occur. In addition, as described above, the strength of the front panel 31 formed as a single plate can also be improved.

[0230] Regarding how low the notch portion 100 is actually, it is sufficient that the notch portion 100 is disposed below the support shaft 101. In this case, in the cabin 1 of the present embodiment, the opening frame 102 of the panel support frame 95 is disposed along the back surface of the front panel 31, but it is preferable that the portion disposed along the back surface of the front panel 31 is not provided above the opening frame 102. That is, the opening frame 102 and the front panel 31 in front of the opening frame 102 are fixed in a surface contact state, but the panel support frame 95 is not provided in front of the front panel 31 even slightly above the opening frame 102, and there is nothing to block the view from the front panel 31. By adopting such an arrangement, the visibility from the cabin 1 can be surely improved.

[0231] Next, the positional relationship between the clutch housing 107 and the frame plate 106 will be described with reference to FIG. 27.

[0232] FIG. 27 shows a cross-sectional view when the cabin 1 is cut in the middle in the left-right direction.

[0233] As shown in FIG. 27, the frame plate 106 of the base frame 103 is inclined so as to shift upward (downward as it goes backward) as it goes from the rear toward the upper part of the opening frame 102. The inclination of the frame plate 106 is to avoid interference with the clutch housing 107 disposed below the driver's seat 6. That is, the tractor 2 of the present embodiment is provided with an engine (prime mover E1) in front of the cabin 1, and a flywheel and a clutch plate are provided at the rear part of the engine. For example, the flywheel has to be vertically long in order to exhibit sufficient inertial force, and thus the front end of the clutch housing 107 is inclined so as to become wider in the vertical direction as it goes forward so as to accommodate the flywheel and the like. In order to correspond to such a clutch housing 107 whose front end is wider in the vertical direction, it is preferable to incline the front end of the lower part of the cabin 1 as well. In particular, in the tractor 2 where vibration is likely to be applied during work, it is necessary to provide a sufficient space between the clutch housing 107 with an inclined front end to avoid interference with the clutch housing 107. Further, as shown in FIG. 27, the lower steering shaft 104b connected to the lower end of the upper steering shaft 104a penetrates through the through hole 105 formed in the right closing plate 116b of the frame plate 106 and protrudes outside the cabin 1. The lower end of the lower steering shaft 104b is power-transmitted outside the cabin 1 via a universal joint. Therefore, in order to provide a universal joint that requires a relatively large installation space, it is also necessary to provide a sufficient space between the clutch housing 107, and the front end of the cabin 1 is inclined forward and upward.

[0234] The cabin 1 of the present embodiment provides a sufficient space between it and the clutch housing 107. Although the front end is inclined, the inclination amount of the front end is minimized as much as possible, and by suppressing the width along the vertical direction of the notch 100 of the front panel 31 to be low, a wide view from the front panel 31 can be secured. That is, the cabin 1 of the present embodiment can avoid physical interference with the clutch housing 107 and secure an installation space for members such as a universal joint while suppressing the width along the vertical direction of the notch 100 of the front panel 31 to be low, and improve the view from the front panel 31.

[0235] As shown in FIG. 27, in the cabin 1 of the present embodiment, the front panel 31 is curved so that the middle in the vertical direction protrudes forward with respect to the lower end. That is, the middle in the vertical direction of the front panel 31 protrudes forward compared to the lower end. Therefore, it is preferable that the opening frame 102 has a forward-inclined posture in which the middle in the vertical direction protrudes forward with respect to the lower end so as to be able to make surface contact with the front panel 31 curved in this way.

[0236] In addition, in the cabin 1 of the present embodiment, the front panel 31 is curved so that the middle in the left-right direction protrudes forward with respect to both the left and right ends. That is, the middle in the left-right direction of the front panel 31 protrudes forward compared to both ends in the left-right direction. Therefore, it is preferable that the opening frame 102 has a curved shape in which the middle in the left-right direction protrudes forward so as to be able to make surface contact with the front panel 31 curved in this way.

[0237] Furthermore, in the cabin 1 of the present embodiment, the front panel 31 is curved so that the middle in the vertical direction protrudes forward with respect to the lower end, and it is preferable that the left front pillar 13L and the right front pillar 13R have a forward-inclined posture in which the middle in the vertical direction protrudes forward with respect to the lower end in accordance with the curvature of the front panel 31.

[0238] In the case of such a cabin 1, even for a full-round type front panel 31 that curves so that the center protrudes forward, the periphery of the notch 100 of the front panel 31 can be brought into close contact with the opening frame 102 of the panel support frame 95, or both ends of the front panel 31 can be brought into close contact with the left front pillar 13L and the right front pillar 13R, so that the front panel 31 can be firmly fixed.

[0239] The cabin 1 of the present embodiment includes a front panel 31 disposed in front of the driver's seat 6, a left door 27L disposed on the left side of the driver's seat 6, a right door 27R disposed on the right side 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. The left front pillar 13L and the right front pillar 13R are made of long members (front pillar long members 34F) having the same shape that curve so as to bulge forward.

[0240] The left front pillar 13L and the right front pillar 13R are composed of frame members in which the longitudinal ends of the long members (front pillar long members 34F) are cut off and the portions other than the longitudinal ends have the same shape.

[0241] The cabin 1 of the present embodiment includes a front panel 31 disposed in front of the driver's seat 6, a left door 27L disposed on the left side of the driver's seat 6, a right door 27R disposed on the right side 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. The left front pillar 13L and the right front pillar 13R are made of long members (front pillar long members 34F) that curve so as to bulge forward in the entire region from the upper end to the lower end, 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.

[0242] For such a cabin 1, by simply selecting whether to perform inversion in the longitudinal direction before cutting, it is possible to process either the left front pillar 13L or the right front pillar 13R from a single long member 34F for the front pillar. In other words, the long member 34F for the front pillar serves as a processing raw material (a common processing raw material for the left front pillar 13L and the right front pillar 13R) that can select the left front pillar 13L and the right front pillar 13R depending on whether inversion is performed. Therefore, if the long member 34F for the front pillar, which is a common raw material, is subjected to die forming or bending, the labor for die forming and bending can be completed with just one operation. However, with the conventional processing method, it was necessary to individually process the left front pillar 13L and the right front pillar 13R with separate dies or to perform bending separately, which required a great deal of time and cost for the labor of die forming and bending. Therefore, in the cabin 1 of the present embodiment, by adopting the long member 34F for the front pillar as a common processing raw material for the left front pillar 13L and the right front pillar 13R, it is possible to suppress an increase in manufacturing costs.

[0243] The cabin 1 of the present embodiment includes a rear panel 32 disposed behind the 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 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. The left rear pillar 14L and the right rear pillar 14R are made of a frame member in which the longitudinal ends of a long member (long member 34R for the rear pillar) are cut, and the portions other than the longitudinal ends have the same shape.

[0244] The left rear pillar 14L and the right rear pillar 14R are composed of frame members in which the longitudinal ends of a long member (long member 34R for the rear pillar) are cut, and the portions other than the longitudinal ends have the same shape.

[0245] The cabin 1 of the present embodiment includes a rear panel 32 disposed behind the 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 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. The left rear pillar 14L and the right rear pillar 14R are formed of a long member (long member 34R for rear pillar) that curves rearward 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 the midpoint in the vertical direction as the boundary.

[0246] The cabin 1 of the present embodiment includes 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 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. The left side beam 18L and the right side beam 18R are formed of long members (long members 34S for side beam) having the same shape that curve upward so as to bulge in the entire region from the front end to the rear end.

[0247] The left side beam 18L and the right side beam 18R are composed of frame members in which the longitudinal ends of the long members (long members 34S for side beam) are cut, and the portions other than the longitudinal ends have the same shape.

[0248] The cabin 1 of the present embodiment includes 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 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. The left side beam 18L and the right side beam 18R are formed of long members (long members 34S for side beam) that curve upward 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 the midpoint in the front-rear direction as the boundary.

[0249] For such a cabin 1, by simply selecting whether to perform inversion in the longitudinal direction before cutting, it is possible to process either the left side beam 18L or the right side beam 18R from a single long member 34S for side beams. In other words, the long member 34S for side beams serves as a processing raw material (a common processing raw material for the left side beam 18L and the right side beam 18R) that allows for the selection of either the left side beam 18L or the right side beam 18R depending on whether inversion is performed. Therefore, by subjecting the common raw material, the long member 34S for side beams, to die forming or bending, the labor for die forming and bending can be completed with just one operation. However, with conventional processing methods, it was necessary to individually process the left side beam and the right side beam using separate dies or to perform bending separately, resulting in a significant amount of time and cost required for die forming and bending. Therefore, in the cabin 1 of the present embodiment, by adopting the long member 34S for side beams as a common processing raw material for the left side beam 18L and the right side beam 18R, it is possible to suppress an increase in manufacturing costs.

[0250] Each of the long members (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) is formed such that the radius of curvature in the middle part of the longitudinal direction is larger than the radius of curvature at both ends in the longitudinal direction.

[0251] For such a cabin 1, the processed front pillar 13, rear pillar 14, or side beam 18 can reduce the difference in curvature from the frame members connected to itself, and it is possible to obtain a cabin 1 that is smoothly connected without giving an appearance where the frame members are bent.

[0252] Between both ends and the middle part in the longitudinal direction of the long member, the radius of curvature is formed to be larger than that of both ends and smaller than that of the middle part in the longitudinal direction.

[0253] For such a cabin 1, even when connecting frame members with a difference in curvature, it is possible to obtain a cabin 1 that is smoothly connected without giving an appearance where the frame members are bent.

[0254] The long member has a main seal surface 54 facing the inner surface of the end and a sub-seal surface 55 facing the end surface of the end with respect to any end of the front panel 31, the rear panel 32, the left door 27L, or the right door 27R. A door seal 46 is provided at the end, which includes a main lip 47 for sealing the main seal surface 54 of the long member and a sub-lip 48 for sealing the sub-seal surface 55 of the long member.

[0255] In such a cabin 1, the main lip 47 and the sub-lip 48 provided on the door seal 46 surely prevent the intrusion of dust and moisture. That is, even if there is dust or moisture that has passed through the sub-lip 48, the dust and moisture that have entered through the gap between the main lip 47 and the sub-lip 48 are excluded, so that the intrusion of dust and moisture can be surely prevented.

[0256] The cabin 1 of the present embodiment includes a left front pillar 13L and a right front pillar 13R 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, and a left door 27L and a right door 27R that are openably and closably arranged behind the left front pillar 13L and the right front pillar 13R. The left front pillar 13L and the right front pillar 13R are formed in a tubular shape with a deformed cross-section. The deformed cross-section includes a first wall portion 60 that constitutes a part of the outer periphery of the tube, a second wall portion 63 that is arranged opposite to the first wall portion 60 and constitutes a part of the outer periphery of the tube, a first connecting wall 61 that connects one end of the first wall portion 60 and 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 and the other end of the second wall portion 63. The first connecting wall 61 and the second connecting wall 62 project outward from the tube, the inner periphery of the first connecting wall 61 is formed in close contact, and the inner periphery of the second connecting wall 62 is formed in close contact. outward and are formed, the inner periphery of the first connecting wall 61 is formed in close contact, and the inner periphery of the second connecting wall 62 is formed in close contact.

[0257] In the case of such a cabin 1, since the second wall portion 63 of the pipe forming the left front pillar 13L and the right front pillar 13R is recessed inward with respect to the first connection wall 61 and the second connection wall 62 that protrude outward, a sufficient space can be secured outside the second wall portion 63 (the recessed portion of the pipe) for arranging the pipes H1 to H3. Further, even when covering the pipes H1 to H3 with the cover 73, the protrusion of the cover 73 outward can be suppressed. Therefore, the left front pillar 13L can be formed to be narrow in the front-rear direction and the left-right direction, and the opening width of the entrance / exit of the cabin 1 and the view of the front panel 31 can be widened, improving the boarding / alighting performance and visibility of the cabin 1.

[0258] The first connection wall 61 and the second connection wall 62 are formed to protrude in directions perpendicular to each other.

[0259] In the case of such a cabin 1, it is possible to securely fix the front panel 31 using the first connection wall 61 and securely fix the left door 27L and the right door 27R using the second connection wall 62.

[0260] The second wall portion 63 is formed to protrude outward from the pipe.

[0261] In the case of such a cabin 1, the cross-sectional area of the irregular cross-section can be widened by the second wall portion 63 protruding outward, and the bending strength of the left front pillar 13L and the right front pillar 13R can be improved.

[0262] 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 in the width direction of the first standing wall portion 64, and a third standing wall portion 66 that bends inward from the other end in the width direction of the first standing wall portion 64.

[0263] In the case of such a cabin 1, a smooth curved surface that is smoothly connected to the front panel 31 can be realized by the first vertical wall portion 64 having an arc-shaped cross section, and an appearance with excellent design can be realized. Further, by providing the second vertical wall portion 65 and the third vertical wall portion 66 that are bent inward of the pipe, the adhesion and sealing properties with respect to the front panel 31, the left door 27L, and the right door 27R can be improved.

[0264] On the second wall portion 63, a peak portion 71 that protrudes most outward from the pipe is provided, and a valley portion 72 that is recessed inward of the pipe from 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.

[0265] In the case of such a cabin 1, by using the peak portion 71 and the valley portion 72, the pipes H1 to H3 can be separately arranged so as not to be entangled.

[0266] The second wall portion 63 is provided with a flat surface that extends in a direction parallel to the tangent line L passing through a point on the outer surface of the first wall portion 60 between the valley portion 72 and the peak portion 71. T and parallel to it.

[0267] In the case of 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.

[0268] The first connecting wall 61 includes a single pipe wall that is overlapped in a bent state with the first folding portion 67 as a boundary, and the inner surface of the first connecting wall 61 located on one side with the first folding portion 67 as a boundary and the inner surface of the first connecting wall 61 located on the other side of the first folding portion 67 are in close contact with each other. and the second connecting wall 62 includes a single pipe wall that is overlapped in a bent state with the second folding portion 68 as a boundary, and the inner surface of the second connecting wall 62 located on one side with the second folding portion 68 as a boundary and the inner surface of the second connecting wall 62 located on the other side of the second folding portion 68 are in close contact with each other.

[0269] In the case of such a cabin 1, it is possible to process the left front pillar 13L and the right front pillar 13R at once from a tubular raw material for processing (long member 34F for the front pillar) having a sealed cross section by using forming or the like.

[0270] 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 contact state. 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 contact state.

[0271] In the case of such a cabin 1, it is also possible to process the left front pillar 13L and the right front pillar 13R by bonding plate-like raw materials or the like.

[0272] The left door 27L and the right door 27R include an inner surface facing the driver's seat 6 and a front end surface facing forward. On the inner surface of the front end of the door panel 27, the main lip 47 of the door seal 46 is arranged to abut against the second connecting wall 62, and on the front end surface, the sub-lip 48 of the door seal 46 is arranged to abut against the second standing wall portion 65.

[0273] In the case of such a cabin 1, the main lip 47 and the sub-lip 48 provided on the door seal 46 surely prevent dust and moisture from entering. That is, even if there is dust or moisture that has passed through the sub-lip 48, the dust and moisture that have entered through the gap between the main lip 47 and the sub-lip 48 are excluded, so that the entry of dust and moisture can be surely prevented.

[0274] A cover 73 that covers the second wall portion 63 from the outside is provided on the second wall portion 63.

[0275] In the case of such a cabin 1, it is possible to hide the pipes H1 to H3, which tend to give a messy appearance, with the cover 73, and the appearance of the interior of the cabin 1 can be improved.

[0276] The cover 73 has a first cover wall 73a extending rearward from an end portion protruding outward of the pipe in the first connection wall 61, and a second cover wall 73b extending inward in the width direction from an end portion protruding outward of the pipe in the second connection wall 62. The first cover wall 73a is located outward in the width direction from a line (front visibility boundary line FL) connecting the center of the driver's seat 6 and the end portion protruding outward of the pipe in the first connection wall 61. The second cover wall 73b is located forward of a line (side visibility boundary line SL) connecting the center of the driver's seat 6 and the end portion protruding outward of the pipe in the second connection wall 62.

[0277] For such a cabin 1, even if the cover 73 is provided, the first cover wall 73a of the cover 73 will not protrude so as to block the forward visibility. Also, the second cover wall 73b of the cover 73 will not protrude so as to block the left boarding and alighting opening 28L, and the opening width of the left boarding and alighting opening 28L of the cabin 1 will not be narrowed. That is, the cover 73 does not narrow the opening width of the left boarding and alighting opening 28L of the cabin 1 or narrow the field of view of the front panel 31. Therefore, the width along the front-rear direction and the width along the left-right direction of the left front pillar 13L as seen from the driver's seat 6 can be maintained in a wide state, and the boarding and alighting performance and visibility of the cabin 1 can be improved.

[0278] The deformed pipe of the present embodiment includes a first wall portion 60 constituting a part of the outer periphery of the pipe, a second wall portion 63 disposed opposite to the first wall portion 60 and constituting a part of the outer periphery of the pipe, one end of the first wall portion 60, and the first connection wall 61 connecting one end of the second wall portion 63, and a second connection wall 62 connecting the other end of the first wall portion 60 and the other end of the second wall portion 63. The first connection wall 61 and the second wall portion 63 are formed to protrude outward of the pipe. The inner periphery of the first connection wall 61 is formed in close contact, and the inner periphery of the second connection wall 62 is formed in close contact.

[0279] For such a deformed pipe, the width along the front-rear direction and the width along the left-right direction can be suppressed without reducing the bending strength of the pipe.

[0280] In the shaped tube of this embodiment, the first connection wall 61 and the second connection wall 62 are formed to project in directions perpendicular to each other.

[0281] In the shaped tube of this embodiment, the second wall portion 63 is formed to project outward from the tube.

[0282] With such a shaped tube, the cross-sectional area of the tube can be increased by the second wall portion 63 that projects outward from the tube, and the bending strength can be enhanced.

[0283] The cabin 1 of this embodiment is provided on the rear side of the driver's seat 6 with a left rear pillar 14L and a right rear pillar 14R that are spaced apart from each other left and right and are formed in a tubular shape extending in the vertical 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 and a right side beam 18R that extend forward from the upper ends of the left rear pillar 14L and the right rear pillar 14R and are formed to curve upward in the entire region from the front end to the rear end. The cabin 1 is formed longer in the front-rear direction than in the left-right direction, and includes left reinforcing members 49L and right reinforcing members 49R that connect the rear beam (rear beam 16) and the left side beam 18L and the right side beam 18R in a crosswise manner through the indoor sides of the left rear pillar 14L and the right rear pillar 14R. The front portions of the left reinforcing members 49L and the right reinforcing members 49R are connected near the center in the front-rear direction of the left side beam 18L and the right side beam 18R.

[0284] With such a cabin 1, the right reinforcing members 49R can increase the load sharing borne by the left rear pillar 14L and the right rear pillar 14R and reduce the load borne by the left front pillar 13L and the right front pillar 13R. As a result, in the cabin 1 of this embodiment, even when a rollover or the like occurs, deformation and damage of the cabin 1 can be suppressed, and the safety can be dramatically improved compared to conventional cabins.

[0285] 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 and right portions of the rear beam 16), and a central base portion 85 provided between the first connection portion 82 and the second connection portion 84. The central base portion 85 is joined to the outer peripheral surfaces on the interior side of the left rear pillar 14L and the right rear pillar 14R, and the distance (L1) between the first connection portion 82 and the central base portion 85 is greater than the distance (L2) between the second connection portion 84 and the central base portion 85.

[0286] For such a cabin 1, the left reinforcing member 49L and the right reinforcing member 49R can further reduce the load borne by the left front pillar 13L and the right front pillar 13R. Therefore, it is possible to further improve the safety compared to a conventional cabin.

[0287] The left reinforcing member 49L and the right reinforcing member 49R have a roof seal surface 88 on which a roof seal 45 for sealing between the roofs 9 arranged above the driver's seat 6 is placed. The roof seal surface 88 is provided between the first connection portion 82 and the second connection portion 84 and is flush with the upper surfaces of the left side beam 18L and the right side beam 18R to form a first seal surface 89. It is also provided between the first connection portion 82 and the second connection portion 84 and is flush with the upper surface of the rear beam 16 to form a second seal surface 90, and a third seal surface 91 formed on the upper surface of the central base portion 85 and formed between the first seal surface 89 and the second seal surface 90. The first seal surface 89 and the third seal surface 91 are continuously formed, and the second seal surface 90 and the third seal surface 91 are continuously formed.

[0288] In the case of such a cabin 1, the roof seal 45 can be continuously arranged so as to go around the periphery of the driver's seat 6 without suddenly changing its height vertically. In particular, in some conventional cabins, the height of the rear beam is lower than that of the right side beam. In such conventional cabins, the seal member may be interrupted around the rear beam, and sufficient sealing performance may not be exhibited. However, in the cabin 1 of the present embodiment using the reinforcing member 49 having the roof seal surface 88, the roof seal 45 can be arranged without interruption, and it is possible to exhibit sufficient sealing performance.

[0289] For the side beam 18 and the rear lower frame 17 (which may be referred to as the rear beam), a frame member having a U-shaped cross section that opens toward the indoor side is used. The side beam 18 is provided with a first fixing plate 42 that closes the opening of the side beam 18 and to which the first connecting portion 82 is connected. 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 connecting portion 84 is connected.

[0290] In the case of such a cabin 1, the above-described reinforcing member 49 can be firmly fixed to the side beam 18 and the rear lower frame 17, and it is possible to connect the rear beam 16, the upper part of the rear pillar 14, and the side beam 18 using the reinforcing member 49. As a result, the side beam 18 can be firmly supported with respect to the rear beam 16 and the upper part of the rear pillar 14 using the reinforcing member 49, and it is possible to increase the load-bearing capacity of the cabin 1.

[0291] The first connecting portion is provided in the middle in the vertical direction of the first fixing plate, and the second connecting portion is provided in the middle in the vertical direction of the second fixing plate.

[0292] In the case of such a cabin 1, welding can be performed below the upper surface of the upper wall portion 39 of the side beam 18. Therefore, 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, and it is possible to enhance the sealing performance of the roof seal 45.

[0293] The cabin 1 of this embodiment is equipped with a front panel 31 arranged in front of the driver's seat 6 so as to curve forward in a protruding manner, and a support structure 99 that supports the front panel 31. 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. The front panel 31 is formed as a single plate with a cutout portion 100 at its lower end that opens downward. The pedal support portion 98 has a support shaft 101 that supports the brake pedal 97 in a swingable manner. 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 is positioned below the support shaft 101.

[0294] With such a cabin 1, the cutout 100 can be kept small, the labor required for cutting the front panel 31 is reduced, and breakage is less likely to occur. Furthermore, by keeping the cutout 100 low and small in area, the field of view of the front panel 31 can be widened, and visibility from the cabin 1 can be improved.

[0295] Regarding how low the cutout portion 100 should actually be, it is sufficient that the cutout portion 100 is disposed below the support shaft 101. In the bin 1, the opening frame 102 of the panel support frame 95 is disposed along the back surface of the front panel 31, but it is preferable to dispose it so that there is no portion disposed along the back surface of the front panel 31 above the opening frame 102. In other words, the opening frame 102 and the front panel 31 in front of the opening frame 102 are fixed in a surface contact state, 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 there is nothing to obstruct the view from the front panel 31. By adopting such a disposition, it is possible to reliably improve visibility from the cabin 1.

[0296] The panel support frame 95 has a base frame 103 provided in connection with the periphery of the opening frame 102. The base frame 103 has a frame plate 106 having a through hole 105 through which a steering shaft 104 extending from the front of the driver's seat 6 toward the front lower side penetrates. The frame plate 106 is inclined so as to shift upward as it goes from the rear toward the upper part of the opening frame 102 in order to avoid interference with the clutch housing 107 disposed below the driver's seat 6.

[0297] For such a cabin 1, while improving the visibility from the front panel 31, the inclined frame plate 106 avoids physical interference with the clutch housing 107, and it is also possible to secure a space for installing members such as a universal joint below the frame plate 106.

[0298] The support shaft 101 is arranged with its axis oriented in the left - right direction. The pedal support portion 98 has a left first frame 108 that supports the left end of the support shaft 101 with respect to the left end of the base frame 103, a left second frame 109 that supports the left end of the opening frame 102 with respect to the left first frame 108, a central frame 110 that supports the mid - point of the support shaft 101 in the left - right direction with respect to the central portion of the base frame 103, a right first frame 111 that supports the right end of the support shaft 101 with respect to the right end of the base frame 103, and a right second frame 112 that supports the right end of the opening frame 102 with respect to the right first frame 111.

[0299] For such a cabin 1, by using five frames, namely the left first frame 108, the left second frame 109, the central frame 110, the right first frame 111, and the right second frame 112, for support, it is possible to firmly support the support portion main body 118 (pedal support portion 98) at a position separated upward from the base frame 103 (panel support frame 95).

[0300] A connecting and reinforcing frame 113 that connects the two frames in the left - right direction is provided between the left first frame 108 and the right first frame 111.

[0301] In the case of such a cabin 1, the support strength of the pedal support portion 98 is further improved by the connection reinforcement frame 113.

[0302] At the left and right ends of the front panel 31, a left front pillar 13L and a right front pillar 13R for supporting the front panel 31 are respectively provided. At the upper end of the front panel 31, a front beam 15 connected to the upper ends of the left front pillar 13L and the right front pillar 13R and curved in a protruding shape upward is provided. Above the driver's seat 6, a roof 9 is provided. The weight of the roof 9 is supported by the left front pillar 13L, the right front pillar 13R, and the front panel 31 via the front beam 15.

[0303] In the case of such a cabin 1, it is possible to disperse and support the weight of the roof 9, the weight of the air conditioner and the like provided in the roof 9, and further the weight of the front panel 31 itself by the left front pillar 13L and the right front pillar 13R without concentrating them only on the front panel 31. This is possible.

[0304] The brake pedal 97 includes a left brake pedal 97L for operating the left brake and a right brake pedal 97R for operating the right brake. Between the left brake pedal 97L and the right brake pedal 97R, an interlocking member 114 for operating the left brake pedal 97L and the right brake pedal 97R in an interlocking manner is provided. An interlock release pedal 124 for releasing 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. The frame of the pedal support portion 98 on the side where the interlock release pedal 124 is provided is formed such that the middle side in the vertical direction bends inward in the horizontal direction.

[0305] A clutch member for switching power transmission is provided at the left end of the support shaft 101, and the pedal support portions on the side where the clutch member is provided are both formed such that the middle portion in the vertical direction bends inward in the horizontal direction.

[0306] In such a cabin 1, even if there are members such as the interlock release pedal 124 and the clutch member on either side of the support structure 99, when stepping on the interlock release pedal 124, the clutch member, etc., the frame of the pedal support portion 98 will not get in the way, and the interlock release and the operation of the clutch member can be performed reliably.

[0307] The front panel 31 is curved such that the middle portion in the vertical direction protrudes forward with respect to the lower end, and the opening frame 102 is in a forward-tilted posture where the middle portion in the vertical direction protrudes forward with respect to the lower end in accordance with the curvature of the front panel 31.

[0308] The front panel 31 is curved such that the middle portion in the vertical direction protrudes forward with respect to the lower end, and the left front pillar 13L and the right front pillar 13R are in a forward-tilted posture where the middle portion in the vertical direction protrudes forward with respect to the lower end in accordance with the curvature of the front panel 31.

[0309] In such a cabin 1, even for a full-round type front panel 31 that curves so that the center protrudes forward, it is possible to securely fix the front panel 31 by bringing the periphery of the notch portion 100 of the front panel 31 into close contact with the opening frame 102 of the panel support frame 95, or bringing both ends of the front panel 31 into close contact with the left front pillar 13L and the right front pillar 13R.

[0310] It should be noted that the embodiments disclosed this time should be considered illustrative in all respects and not restrictive. In particular, in the embodiments disclosed this time, matters not explicitly disclosed, such as operating conditions, operation conditions, various parameters, dimensions, weights, volumes of components, etc., do not deviate from the scope normally implemented by those skilled in the art, and those skilled in the art would adopt values that can be easily assumed.

Explanation of Reference Numerals

[0311] 1 Cabin 6 Driver's Seat 14L Left Rear Pillar 14R Right Rear Pillar 16 Rear Upper Beam 18L Left Side Beam 18R Right Side Beam 39 Upper Wall Portion of Side Beam 42 First Fixing Plate 45 Roof Seal 49L Left Reinforcing Member 49R Right Reinforcing Member 82 First Connection Portion 83 Second Fixing Plate 84 Second Connection Portion 85 Central Base 88 Roof Seal Surface 89 First Seal Surface Portion 90 Second Seal Surface Portion 91 Third Seal Surface Portion

Claims

1. A cabin that is formed longer in the front-rear direction than in the left-right direction, and includes a rear pillar that is provided on the rear side of the driver's seat with a distance therebetween left and right and is formed in a tubular shape extending in the vertical direction, a rear beam that connects the upper ends of the rear pillars in the left-right direction and is formed to extend in the left-right direction, and a side beam that extends forward from the upper end of the rear pillar and is formed to curve upward in the entire region from the front end to the rear end. The cabin includes a reinforcing member that connects the rear beam and the side beam in a crosswise manner through the inner side of the rear pillar in the cabin. The front portion of the reinforcing member is connected to the vicinity of the central portion in the front-rear direction of the side beam.

2. The reinforcing member has a first connection portion connected to the side beam, a second connection portion connected to the rear beam, and a central base portion provided between the first connection portion and the second connection portion. The central base portion is joined to the outer peripheral surface on the inner side of the rear pillar in the cabin. The cabin according to Claim 1, wherein the distance between the first connection portion and the central base portion is greater than the distance between the second connection portion and the central base portion.

3. The reinforcing member has a roof seal surface on which a seal member for sealing the gap between the reinforcing member and a roof disposed above the driver's seat is mounted. The roof seal surface has a first seal surface portion that is provided between the first connection portion and the second connection portion and is flush with the upper surface of the side beam. has a second seal surface portion that is provided between the first connection portion and the second connection portion and is flush with the upper surface of the rear beam. has a third seal surface portion that is formed on the upper surface of the central base portion and is formed between the first seal surface portion and the second seal surface portion. and has The cabin according to Claim 2, wherein the first seal surface portion and the second seal surface portion are substantially flush.

4. A U-shaped cross-section frame member that opens toward the inner side of the cabin is used for the side beam and the rear beam. The side beam is provided with a first fixing plate that closes the opening of the side beam and to which the first connection portion is connected. The rear beam is provided with a second fixing plate that closes the opening of the rear beam and to which the second connection portion is connected. The cabin according to Claim 2 or 3.

5. The cabin according to claim 4, which cites claim 2, wherein the first connecting portion is provided in the vertical middle of the first fixing plate, and the second connecting portion is provided in the vertical middle of the second fixing plate.

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