Cabin

Abstract

Provided is a cabin with which sealability at a joint site between a rear-lower frame and a rear pillar can be improved.　This cabin (1) is provided with: a rear panel (32) that is disposed on the rear side of a driver seat (6); a rear-lower frame (17) that is disposed on the lower side of the rear panel (32); and rear pillars (14L, 14R) that are disposed on the left and right sides of the rear panel (32). The rear-lower frame (17) is configured from a stepped member (202) that protrudes in a stepwise manner toward the rear, and is curved so that the central portion (17C) declines downward relative to both ends (17L, 17R) in the left-right direction.

Description

cabin

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

[0002] Patent Document 1 discloses a cabin that combines long frames such as front pillars, rear pillars, front upper frames, front lower frames, rear upper frames, rear lower frames, side upper beams, and side lower beams.

[0003] Japanese Patent Publication No. 2020-097368

[0004] In the cabin disclosed in Patent Document 1, the joint between the rear lower frame and the rear pillar is disposed so that the rear lower frame and the rear pillar form a substantially right angle when viewed from the front-rear direction.

[0005] However, at locations where frame members are joined at angles close to a right angle, if a seal is provided at that location, the seal will deform significantly, which can easily cause problems with sealing. To solve this problem, it is necessary to make the angle at the joint between the rear lower frame and the rear pillar gentler, but in the case of conventional cabins, the rear lower frame is made of highly rigid square tubes, and adjusting the shape (curvature) of the rear lower frame is difficult, making it difficult to improve sealing.

[0006] The present invention has been made to solve the problems of the conventional technology, and aims to provide a cabin that can improve the sealing performance at the joint between the rear lower frame and the rear pillar.

[0007] A cabin according to one embodiment of the present invention comprises a rear panel located behind the driver's seat, a rear lower frame located below the rear panel, and rear pillars located to the left and right of the rear panel, wherein the rear lower frame is composed of a stepped member that protrudes rearward in a stepped manner and is curved so that the central portion slopes downward relative to both left and right ends.

[0008] The cabin may include a rear lower glass positioned below and behind the driver's seat, and a support plate supporting the upper part of the rear lower glass, the support plate being positioned to close the opening in front of the stepped member.

[0009] The cabin may include weatherstrips arranged between the rear panel and the rear lower frame, and between the rear panel and the rear pillar, the stepped member having a first sealing surface facing rearward and a second sealing surface facing upward, the weatherstrip being a double lip type having a main lip and a sub-lip, and attached to the rear panel with the main lip in contact with the first sealing surface and the sub-lip in contact with the second sealing surface between the rear panel and the rear lower frame.

[0010] The rear pillar is provided with a rear pillar cover that covers the rear surface of the rear pillar, and the rear pillar cover has a third sealing surface with which the sub-lip of the weatherstrip contacts, the rear surface of the rear pillar and the first sealing surface of the rear lower frame are formed flush with each other, and the second sealing surface and the third sealing surface may be arranged side by side on a curve having a single radius of curvature.

[0011] A fender cover that covers the rear portion of the fender is provided below the rear pillar, and the fender cover has a fourth seal surface with which the sub-lip of the weatherstrip contacts, the rear surface of the fender cover and the first seal surface of the rear lower frame are formed flush with each other, and the second seal surface and fourth seal surface may be arranged side by side on a curve having a single radius of curvature.

[0012] The rear lower frame has a tip surface that protrudes toward the rear, a lower surface that is formed adjacent to the front portion of the tip surface and faces downward, the second seal surface that is formed adjacent to the front portion of the tip surface and faces upward, the first seal surface that is formed adjacent to the front portion of the second seal surface and faces rearward, and an upper surface that is formed adjacent to the front portion of the first seal surface and faces upward, and the upper surface and the lower surface are inclined surfaces that slope downward as they extend toward the rear, and the upper surface may be drawn so that its angle of inclination with respect to the horizontal direction is greater than that of the lower surface.

[0013] The rear lower frame may have a central portion curved with a first radius of curvature and an end portion curved with a second radius of curvature, and the first radius of curvature and the second radius of curvature may be different from each other.

[0014] The first radius of curvature may be greater than the second radius of curvature.

[0015] According to the cabin, it is possible to improve the sealing performance at the joint between the rear lower frame and the rear pillar.

[0016] 1 is a left side view of a tractor. FIG. 1 is a perspective view of a cabin as viewed from the left front. FIG. 2 is a right side view of the cabin. FIG. 3 is a front view of the cabin. FIG. 4 is a plan view of the cabin. FIG. 5 is a rear view of the cabin. FIG. 6 is a perspective view of the cabin as viewed from the left rear. FIG. 7 is a longitudinal cross-sectional view of a rear lower frame. FIG. 8 is a perspective view of a rear lower frame. FIG. 9 is a diagram showing a comparison of the inclination angles of the upper and lower surfaces of the rear lower frame. FIG. 10 is a rear view of the rear lower frame. FIG. 11 is a plan view of the rear lower frame. FIG. 12 is a perspective view showing a connection portion between the rear lower frame and a rear pillar. FIG. 13 is a front view of an exhaust system. FIG. 14 is a perspective view showing a connection portion between the rear lower frame, rear pillar, and side frame as viewed from the upper front left. FIG. 15 is a perspective view showing a connection portion between the rear lower frame, rear pillar, and side frame as viewed from the lower rear. FIG. 16 is an exploded perspective view of an exhaust system. FIG. 17 is a longitudinal cross-sectional view and a partially enlarged perspective view of an exhaust system. FIG. 18 is a diagram showing the lower part of the boarding entrance on the left side of the cabin. FIG. 19 is a side view showing a connection portion between a side lower beam and a connecting frame. FIG. 19 is a side view showing a connection portion between a side lower beam and a connecting frame in a conventional cabin. FIG. 20 is a diagram showing the periphery of the left front pillar of the cabin. FIG. 1 is an exploded perspective view showing the arrangement of the left front part of the cabin (left connecting frame, front lower frame), left front pillar, air conditioning hose, and bracket. FIG. 2 is a perspective view of the reinforcing bracket as seen from above. FIG. 3 is a perspective view showing the positional relationship between the reinforcing bracket and the opening frame. FIG. 4 is a perspective view showing the positional relationship between the reinforcing bracket and the connecting frame. FIG. 5 is a perspective view showing the positional relationship between the left and right reinforcing brackets and the mounting members. FIG. 6 is a perspective view showing the mounting positions of the reinforcing brackets relative to the mounting members. FIG. 7 is a perspective view showing the reinforcing bracket provided with an internal rib.

[0017] The cabin 1 of this embodiment will be described below with reference to the drawings as appropriate.

[0018] 1 shows a side view of a tractor 2 having a cabin 1 according to the present embodiment. In the present embodiment, the tractor 2 is exemplified as a work machine (vehicle) on which the cabin 1 of the present invention is mounted. However, a wheel loader, a backhoe, or the like may also be used as the work machine on which the cabin 1 of the present invention is mounted.

[0019] In this specification, the direction of arrow A1 in FIG. 1 (the forward direction of the tractor 2) will be referred to as the forward direction, the direction of arrow A2 in FIG. 1 (the reverse direction of the tractor 2) will be referred to as the rearward direction, and the direction of arrow A3 in FIG. 1 will be referred to as the front-to-rear direction. Therefore, the front of FIG. 1 corresponds to the left when describing the tractor 2 and the cabin 1, and the back of FIG. 1 corresponds to the right when describing the tractor 2 and the cabin 1. These directions correspond to the directions as seen by an operator OP (hereinafter, the person (driver) who drives and operates the tractor 2 while riding in the driver's seat 6) of the tractor 2. The tractor 2 and the cabin 1 will be described with the horizontal direction perpendicular to the front-to-rear direction A3 as the width direction (or left-to-right direction). Furthermore, the direction from the right to the center or from the left to the center in the width direction of the tractor 2 will be described as the inward width direction. In other words, the inward width direction is the direction toward the center of the tractor 2 in the width direction.

[0020] 1, the tractor 2 has a travelable machine body (vehicle body) 3. The machine body 3 has a prime mover E1 and a transmission case 4.

[0021] The prime mover E1 generates driving force to propel the machine body 3, and in this embodiment, a diesel engine is used. The prime mover E1 is located at the front of the tractor 2 and is covered by a bonnet 10. The bonnet 10 has a curved top surface that protrudes slightly upward, and has a space inside that can store the prime mover E1. In the tractor 2 of this embodiment, the prime mover E1 is stored in the space inside the bonnet 10.

[0022] It should be noted that, instead of the diesel engine used in this embodiment, an electric motor may be used as the prime mover E1, or a hybrid type that combines a diesel engine and an electric motor may be used.

[0023] The transmission case 4 is configured by directly connecting, for example, a flywheel housing that accommodates a flywheel, a clutch housing 107 (see Figure 1) that accommodates a clutch that intermittently transmits the power of the prime mover E1 transmitted via the flywheel, and a transmission case that accommodates a transmission that changes the speed of the power transmitted via the clutch.

[0024] As shown in Fig. 1, the tractor 2 has a traveling device 5 that supports the machine body 3 so that it can travel. The traveling device 5 of the tractor 2 of this embodiment illustrated in Fig. 1 is a wheel type (four-wheel type) that has a left front wheel 11L and a right front wheel 11R arranged at the front of the machine body 3, and a left rear wheel 12L and a right rear wheel 12R arranged at the rear of the machine body 3. In other words, the tractor 2 of this embodiment has a traveling device 5 that travels on four wheels: the left front wheel 11L, the right front wheel 11R, the left rear wheel 12L, and the right rear wheel 12R.

[0025] 1, the cabin 1 is a room where an operator OP enters to drive and operate the machine body 3, and in this embodiment, is mounted at the rear of the machine body 3. A driver's seat 6 where the operator OP sits is provided at the rear of the interior of the cabin 1 (referred to as the cabin interior). A steering handle 7 for steering, for example, a left front wheel 11L and a right front wheel 11R is provided in front of the driver's seat 6.

[0026] As shown in Figures 1 and 2, the cabin 1 has a cabin frame 8 in which long frame members are combined in a three-dimensional, tower-like configuration. In other words, the cabin frame 8 forms the framework (exoskeleton) of the cabin 1 and has a plurality of long frame members. In addition, panel members such as a front panel 31 and doors (door panels 27), which will be described later, are arranged between the three-dimensional, tower-like combined frame members in the cabin frame 8. In addition, a roof 9 is provided on the upper part of the cabin frame 8. As shown in Figure 2, the cabin frame 8 of this embodiment is a four-pillar type that does not have a center pillar (quarter pillar).

[0027] 2 to 6 (particularly in detail in FIG. 2), the cabin frame 8 has a plurality of long frame members. In the present embodiment, the cabin frame 8 is made up of eleven frame members: a left front pillar 13L, a right front pillar 13R, a left rear pillar 14L, a right rear pillar 14R, a front beam 15, a rear beam 16, a rear lower frame 17, a left side beam 18L, a right side beam 18R, a left side lower beam 19L, and a right side lower beam 19R. Each frame member that makes up the cabin frame 8 will be described in detail below.

[0028] As shown in detail in FIGS. 2 to 5 , a left front pillar 13L and a right front pillar 13R are provided in the front portion of the cabin frame 8 (in front of the driver's seat 6). The left front pillar 13L and the right front pillar 13R are arranged side by side with a gap in the width direction, and both are arranged to extend in the up-down direction. The left front pillar 13L is provided at the left front corner of the cabin 1. The right front pillar 13R is provided at the right front corner of the cabin 1. A front beam 15 spans between the upper portion of the left front pillar 13L and the upper portion of the right front pillar 13R. In other words, the upper portion of the left front pillar 13L and the upper portion of the right front pillar 13R are connected laterally by the front beam 15.

[0029] In the following description, the left front pillar 13L and the right front pillar 13R may be collectively referred to as the front pillars 13.

[0030] As shown in Figures 2, 3, 5, and 6, a left rear pillar 14L and a right rear pillar 14R are disposed at the rear of the cabin frame 8 (behind the driver's seat 6). The left rear pillar 14L and the right rear pillar 14R are arranged side by side with a gap in the width direction and are both disposed to extend in the up-down direction. The left rear pillar 14L is disposed at the left rear corner of the cabin 1. The right rear pillar 14R is disposed at the right rear corner of the cabin 1. A rear beam 16 spans between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. In other words, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected laterally by the rear beam 16. In addition, a rear lower frame 17 spans between the lower part of the left rear pillar 14L and the lower part of the right rear pillar 14R. That is, the lower portion of the left rear pillar 14L and the lower portion of the right rear pillar 14R are connected to each other laterally by the rear lower frame 17.

[0031] In the following description, the left rear pillar 14L and the right rear pillar 14R may be collectively referred to as the rear pillar 14.

[0032] As shown in Figures 2, 3, and 5, a left side beam 18L and a right side beam 18R are provided on the upper portion of the cabin frame 8. The left side beam 18L and the right side beam 18R are arranged side by side with a gap in the width direction and are both arranged to extend in the front-to-rear direction. The left side beam 18L is curved so that its midpoint in the front-to-rear direction bulges upward compared to its front and rear ends. The right side beam 18R is curved so that its midpoint in the front-to-rear direction bulges upward compared to its front and rear ends.

[0033] The left side beam 18L spans between an upper portion of the left front pillar 13L and an upper portion of the left rear pillar 14L. In other words, the upper portion of the left front pillar 13L and the upper portion of the left rear pillar 14L are connected in the front-rear direction by the left side beam 18L.

[0034] The right side beam 18R spans between the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R. In other words, the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R are connected in the front-rear direction by the right side beam 18R.

[0035] In the following description, the left side beam 18L and the right side beam 18R may be collectively referred to as the side beams 18.

[0036] 2 and 3, a left side lower beam 19L and a right side lower beam 19R are provided at the bottom of the cabin frame 8. The left side lower beam 19L and the right side lower beam 19R are arranged side by side with a gap in the width direction.

[0037] The left side lower beam 19L is formed in an arc extending downward and forward from the lower part of the left front pillar 13L. That is, the left side lower beam 19L extends downward as it extends forward from the lower part of the left rear pillar 14L. The lower end of the left side lower beam 19L, which extends downward, is connected in the fore-and-aft direction to the lower end of the left front pillar 13L via the left connecting frame 20L.

[0038] The right side lower beam 19R is formed in an arc extending downward and forward from the lower part of the right front pillar 13R. That is, the right side lower beam 19R extends downward as it extends forward from the lower part of the right rear pillar 14R. The lower end of the right side lower beam 19R, which extends downward, is connected in the longitudinal direction to the lower end of the right front pillar 13R via a right connecting frame 20R.

[0039] Hereinafter, the left side lower beam 19L and the right side lower beam 19R will be collectively referred to as the side lower beam 19.

[0040] 2, a fender 21L (left rear wheel fender) covering the left rear wheel 12L is fixed to the lower surface of the left side lower beam 19L and the lower end of the left rear pillar 14L. Also, a fender 21R (right rear wheel fender) covering the right rear wheel 12R is fixed to the lower surface of the right side lower beam 19R and the lower end of the right rear pillar 14R.

[0041] As shown in FIGS. 2, 4, 5, and 6, a front beam 15 is provided at the front of the upper portion of the cabin frame 8, and a rear beam 16 is provided at the rear.

[0042] The front beam 15 and rear beam 16 are arranged side by side with a gap in the fore-and-aft direction, and are both formed as long frame members extending in the left-right direction. The front beam 15 is curved so that its midpoint in the left-right direction bulges upward compared to the left and right ends. The rear beam 16 extends linearly in the left-right direction with almost no change in height in the up-down direction.

[0043] The front beam 15 spans between the upper part of the left front pillar 13L and the upper part of the right front pillar 13R. In other words, the upper part of the left front pillar 13L and the upper part of the right front pillar 13R are connected laterally by the front beam 15.

[0044] The rear beam 16 spans between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. In other words, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected laterally by the rear beam 16.

[0045] As described above, the cabin frame 8 of this embodiment is formed by combining frame materials such as the above-mentioned left front pillar 13L, right front pillar 13R, left rear pillar 14L, right rear pillar 14R, front beam 15, rear beam 16, rear lower frame 17, left side beam 18L, right side beam 18R, left side lower beam 19L, and right side lower beam 19R.

[0046] As shown in Figures 2 and 5, a floor sheet 22 is provided between the fender 21L (left rear wheel fender) and the fender 21R (right rear wheel fender). The floor sheet 22 is arranged horizontally below the driver's seat 6, and the driver's seat 6 is attached on top of this floor sheet 22. The rear portion of the floor sheet 22 extends obliquely rearward and upward, and is located behind the driver's seat 6. A step 23 that forms part of the floor is disposed forward from the front lower end of the floor sheet 22 and is located at a position lower than the floor sheet 22. The step 23 is a board (step board) that forms the floor of the cabin 1. The operator OP seated in the driver's seat 6 can place his / her feet on the upper surface of the step 23.

[0047] 1, 3, 4, and 6, the roof 9 is disposed on top of the cabin frame 8 and is capable of preventing wind, rain, and direct sunlight from entering the cabin 1. The roof 9 has an inner roof 24 that forms the ceiling portion and the like inside the cabin 1, and an outer roof 25 that forms the upper wall and the like of the ceiling portion. A hollow space is formed between the inner roof 24 and the outer roof 25, and a space is formed in which an air conditioner 26 (air conditioning device) that conditions the air inside the cabin can be placed.

[0048] As shown in Figures 1 and 2, the cabin 1 of this embodiment is configured to allow the operator OP to board from both the left and right sides, and has a left boarding / alighting opening 28L on the left side of the cabin 1 and a right boarding / alighting opening 28R on the right side of the cabin 1. The left boarding / alighting opening 28L is provided with a left door (left door panel 27L) (see Figures 1 and 5) that closes the left boarding / alighting opening 28L. The right boarding / alighting opening 28R is provided with a right door (right door panel 27R) (see Figures 3 and 5) that closes the right boarding / alighting opening 28R. Hereinafter, the left door panel 27L will also be referred to as the left door 27L, and the right door panel 27R will also be referred to as the right door 27R.

[0049] The left entrance 28L is an opening surrounded by the left front pillar 13L, left side beam 18L, left rear pillar 14L, left side lower frame 19L, and left connecting frame 20L, and opens to the left. The left entrance 28L can be closed by a left door 27L. The left door 27L is supported by two door hinges, one above and one below, on the left rear pillar 14L. The two door hinges are a first door hinge 29L provided on the upper part of the left rear pillar 14L and a second door hinge 30L provided below the first door hinge 29L. In other words, the left entrance 28L can be opened and closed by swinging the front end of the left door 27L left and right relative to the rear end, where the first door hinge 29L and the second door hinge 30L are provided.

[0050] The right entrance / exit opening 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 frame 19R, and the right connecting frame 20R, and opens to the right. The right entrance / exit opening 28R can be closed by a right door 27R. The right door 27R is supported by two door hinges, one above and one below, on the right rear pillar 14R. The two door hinges are a first door hinge 29R provided on the top of the right rear pillar 14R and a second door hinge 30R provided below the first door hinge 29R. In other words, the right entrance / exit opening 28R can be opened and closed by swinging the front end of the right door 27R left and right relative to the rear end, where the first door hinge 29R and the second door hinge 30R are provided.

[0051] The left door 27L and the right door 27R described above are formed of light-transmitting panels such as tempered glass or acrylic glass, ensuring good visibility of the outside of the vehicle from inside the cabin 1.

[0052] As shown in FIG. 5 , the cabin 1 of this embodiment includes a front panel 31 at the front of the cabin frame 8 and a rear panel 32 at the rear of the cabin frame 8 .

[0053] The front panel 31 is disposed between a left front pillar 13L and a right front pillar 13R disposed at a distance from each other on the left and right sides, and is supported on the left and right sides by the left front pillar 13L and the right front pillar 13R. The upper edge of the front panel 31 is fixed to a front beam 15 disposed above the front panel 31. Like the left door 27L and the right door 27R described above, the front panel 31 is formed from a light-transmitting panel such as tempered glass or acrylic glass, and good visibility of the outside of the vehicle (forward) from inside the cabin 1 can be ensured.

[0054] The front panel 31 of this embodiment is formed into a curved surface that bulges forward. In other words, when the front panel 31 is cut horizontally, the horizontal cross section of the front panel 31 has an arc shape in which the center in the left-right direction protrudes forward compared to the left and right ends. Furthermore, when the front panel 31 is cut vertically, the vertical cross section of the front panel 31 has an arc shape in which the center in the up-down direction protrudes forward compared to the upper and lower ends. By forming the front panel 31 into a curved surface that bulges forward, it is possible to improve visibility from inside the cabin 1 to the outside of the vehicle, particularly downward.

[0055] The cabin 1 of the present invention has the following features.

[0056] 2, 5, and 7, the cabin 1 of this embodiment includes a front panel 31 in front of the driver's seat 6, a rear panel 32 behind the driver's seat 6, and a rear lower panel 200 behind and below the driver's seat 6. The rear panel 32 and the rear lower panel 200 are both formed into a plate shape curved toward the outside of the vehicle and made of a light-transmitting material such as tempered glass or acrylic glass. The rear panel 32 and the rear lower panel 200 are arranged side by side in the vertical direction, and a rear lower frame 17 is arranged between the rear panel 32 and the rear lower panel 200. The rear lower frame 17 extends in the left-right direction between the rear panel 32 and the rear lower panel 200.

[0057] As shown in Fig. 7 , a weatherstrip 201 is provided around the periphery (edge) of the rear panel 32. As shown in Fig. 8 , the weatherstrip 201 is a double-lip type having a main lip 201a and a sub-lip 201b. The weatherstrip 201 is provided around the entire outer edge of the rear panel 32. In other words, the weatherstrip 201 is also disposed between the rear panel 32 and the rear lower frame 17 provided below the rear panel 32. The weatherstrip 201 is also disposed between the rear panel 32 and the rear pillars 14 provided on the left and right of the rear panel 32.

[0058] Rear pillars 14 are disposed on the left and right of the rear panel 32. The rear pillars 14 are composed of a left rear pillar 14L disposed on the left of the rear panel 32 and a right rear pillar 14R disposed on the right of the rear panel 32. A lower portion of the left rear pillar 14L is joined to the left end of the rear lower frame 17. A lower portion of the right rear pillar 14R is joined to the right end of the rear lower frame 17.

[0059] 8, the rear lower frame 17 is made up of a stepped member 202. The stepped member 202 protrudes rearward in a stepped shape. The stepped member 202 is open at the front.

[0060] 8, the stepped member 202 of this embodiment has a stepped rear surface, of which the rearward facing surface is a first sealing surface 203, and the upward facing surface is a second sealing surface 204. The main lip 201a of the weatherstrip 201 contacts the first sealing surface 203 of the stepped member 202, and the sub-lip 201b of the weatherstrip 201 contacts the second sealing surface 204.

[0061] In detail, the stepped member 202 has a tip surface 202a that protrudes toward the rear, a lower surface 202b that is formed adjacent to the front portion of the tip surface 202a and faces downward, a second sealing surface 204 that is formed adjacent to the front portion of the tip surface 202a and faces upward, a first sealing surface 203 that is formed adjacent to the front portion of the second sealing surface 204 and faces rearward, and an upper surface 202c that is formed adjacent to the front portion of the first sealing surface 203 and faces upward.

[0062] By contacting the main lip 201a of the weatherstrip 201 with the first sealing surface 203 of the stepped member 202 and the sub-lip 201b of the weatherstrip 201 with the second sealing surface 204 of the stepped member 202 to form a seal, the sealing performance between the stepped member 202 and the rear panel 32 can be improved. Even if rainwater attempts to infiltrate the inside of the rear panel 32 by climbing over the sub-lip 201b of the weatherstrip 201, it is blocked by the main lip 201a. Furthermore, because the rear lower frame 17 is curved downward as described below, rainwater that climbs over the sub-lip 201b flows down the space formed between the main lip 201a and the sub-lip 201b along this curve. This allows the infiltrating rainwater to quickly flow downward.

[0063] As shown in Figure 10, the upper surface 202c of the stepped member 202 is an inclined surface that slopes downward toward the rear. In this way, the upper surface 202c of the rear lower frame 17 that supports the lower part of the rear panel 32 is an inclined surface that slopes backward, thereby ensuring a rearward field of view, particularly a downward field of view toward the rear, for the driver (operator OP) through the rear panel 32. The lower surface 202b of the stepped member 202 is also an inclined surface that slopes downward toward the rear. If the inclination angle of the upper surface 202c with respect to the horizontal direction is θ1 and the inclination angle of the lower surface 202b with respect to the horizontal direction is θ2, then θ2 > θ1.

[0064] The stepped member 202 having the above-described shape (a stepped shape with an open front) is formed by sheet metal processing of a metal plate. More specifically, the stepped member 202 is formed by pressing (more specifically, drawing) a metal plate. That is, the rear lower frame 17 made up of the stepped member 202 is formed by pressing (drawing) a metal plate. Therefore, the shape of the rear lower frame 17 can be easily adjusted during processing. Specifically, as will be described later, the rear lower frame 17 is formed in a curved shape, and the degree of curvature can be easily adjusted during processing.

[0065] In conventional cabins, the rear lower frame is made of metal square tubes. Therefore, when making the rear lower frame into a curved shape, the highly rigid square tubes must be bent, making it difficult to adjust the degree of curvature. In particular, it is difficult to change the degree of curvature (radius of curvature) depending on the part of the rear lower frame.

[0066] In contrast, the rear lower frame 17 of the cabin 1 of the present invention is formed from the stepped member 202 by press working (drawing), so the degree of curvature can be easily adjusted during processing. Therefore, it is also easy to change the degree of curvature (radius of curvature) depending on the part of the rear lower frame 17.

[0067] 11 , the rear lower frame 17 is curved such that a center portion 17C thereof is downwardly curved relative to both ends in the left-right direction (a left end 17L and a right end 17R). The rear lower frame 17 is not simply curved downwardly, but is also curved such that the radius of curvature changes depending on the position in the left-right direction. In other words, the radius of curvature of the downward curve of the rear lower frame 17 changes depending on the position in the left-right direction.

[0068] Specifically, the rear lower frame 17 has a central portion 17C curved at a first radius of curvature R1 and end portions (left end 17L, right end 17R) curved at a second radius of curvature R2. In FIG. 11 , the range of the central portion 17C curved at the first radius of curvature R1 is indicated by R1, and the range of the end portions curved at the second radius of curvature R2 is indicated by R2. The central portion 17C, left end 17L, and right end 17R each extend over a predetermined length in the left-right direction. The left-right length of the central portion 17C is greater than the left-right lengths of the left end 17L and right end 17R. The first radius of curvature R1 and the second radius of curvature R2 are different from each other (R1 ≠ R2). Specifically, the first radius of curvature R1 is greater than the second radius of curvature R2 (R1 > R2).

[0069] In this way, by varying the radius of curvature of the downward curve of the rear lower frame 17 depending on the position in the left-right direction, and particularly by making the first radius of curvature R1 larger than the second radius of curvature R2, it is possible to make the angle of the rear lower frame 17 relative to the rear pillar 14 gentler (the angle is larger toward the center of the rear panel 32). This makes it possible to avoid large deformation of the weatherstrip 201 provided between the rear lower frame 17 and the rear pillar 14, and to prevent a decrease in sealing performance near the boundary between the rear lower frame 17 and the rear pillar 14.

[0070] 12, the rear lower frame 17 is curved so that a center portion 17C thereof curves rearward relative to both left and right ends (a left end 17L and a right end 17R). The rear lower frame 17 is not simply curved rearward, but is curved so that the radius of curvature changes depending on the position in the left and right direction. In other words, the radius of curvature of the rearward curve of the rear lower frame 17 changes depending on the position in the left and right direction.

[0071] Specifically, the rear lower frame 17 has a central portion 17C curved at a first radius of curvature R3 and end portions (left end 17L, right end 17R) curved at a second radius of curvature R4. The central portion 17C, left end 17L, and right end 17R each extend over a predetermined length in the left-right direction. The left-right length of the central portion 17C is greater than the left-right lengths of the left end 17L and right end 17R. The first radius of curvature R3 and the second radius of curvature R4 are different from each other (R3 ≠ R4). Specifically, the first radius of curvature R3 is greater than the second radius of curvature R4 (R3 > R4).

[0072] In this way, by changing the radius of curvature of the rearward curve of the rear lower frame 17 depending on the left-right position, it is possible to accommodate cabins of different width sizes. More specifically, by changing the first radius of curvature R3 of the central portion 17C, it is possible to adjust the fore-and-aft position of the driver's seat to accommodate cabins of different width sizes.

[0073] Specifically, as the width of the cabin 1 increases, the length of the rear lower frame 17 in the left-right direction is increased and the first radius of curvature R3 of the central portion 17C is reduced. Reducing the first radius of curvature R3 of the central portion 17C causes the central portion 17C to protrude further rearward than the ends (left end 17L, right end 17R). This increases the space inside the cabin in the front-rear direction, allowing the driver's seat to be shifted rearward. This makes it possible to optimize the fore-and-aft position of the driver's seat for a large cabin with a large width of the cabin 1 by expanding the interior space of the cabin not only in the left-right direction (width direction) but also in the front-rear direction.

[0074] Furthermore, the second radius of curvature R4 of the ends (left end 17L, right end 17R) of the rear lower frame 17 can also be changed to accommodate cabins 1 with different widthwise dimensions. Even when the first radius of curvature R3 is changed, by changing the second radius of curvature R4 separately from the first radius of curvature R3, it is possible to adjust the connection between the ends of the rear lower frame 17 and the rear pillar 14 so that they are smoothly connected. This makes it possible to use the same rear pillar cover 206 and fender cover 207 for cabins 1 with different widthwise dimensions.

[0075] As described above, the radius of curvature of the downward curve and the radius of curvature of the rearward curve of the rear lower frame 17 change depending on the left-right position. By configuring the rear lower frame 17 from the stepped member 202, it is possible to easily realize a shape with such a changing radius of curvature while ensuring sufficient strength (rigidity) and sealing performance for the rear lower frame 17.

[0076] As shown in Figure 8, the front opening of the stepped member 202 is closed by a support plate 208. The support plate 208 is inclined so that it transitions rearward as it extends downward. The upper end of the support plate 208 is joined to the back side of the upper surface 202c of the stepped member 202. The support plate 208 also supports the upper part of the rear lower panel 200. The front surface of the lower part of the support plate 208 is joined to the rear end of the lower surface 202b of the stepped member 202. In this way, the support plate 208 supports the upper part of the rear lower panel 200 and closes the front opening of the stepped member 202.

[0077] An upper portion of the support plate 208 is joined from below to an upper plate portion 202d having an upper surface 202c of the stepped member 202. In addition, a lower portion of the support plate 208 is joined to the front end portion of a lower plate portion 202e having a lower surface 202b of the stepped member 202. In this way, the support plate 208 closes the front opening of the stepped member 202.

[0078] In this way, by constructing the rear lower frame 17 from the stepped member 202 and then joining the stepped member 202 so that the front opening is closed with the support plate 208, it is possible to increase the rigidity (strength) of the rear lower frame 17. Furthermore, by using the support plate 208, which is a member that supports the upper part of the rear lower panel 200, as a member that also increases the rigidity of the rear lower frame 17, it is possible to achieve support for the rear lower panel 200 and increase the rigidity of the rear lower frame 17 with a small number of parts.

[0079] 7, rear pillars 14 are disposed on the left and right of the rear panel 32. The rear pillars 14 include a left rear pillar 14L disposed on the left of the rear panel 32 and a right rear pillar 14R disposed on the right of the rear panel 32. The rear pillars 14 are provided with rear pillar covers 206 that cover the rear surfaces of the rear pillars 14.

[0080] As described above, the weatherstrip 201 has a main lip 201a and a sub-lip 201b, and the lip tips of the main lip 201a and the sub-lip 201b are oriented in directions that intersect with each other (see FIG. 8). Specifically, the main lip 201a extends rearward and forward, and the sub-lip 201b extends downward.

[0081] In the case of the rear lower frame 17 shown in Figure 8, the main lip 201a contacts the first sealing surface 203 facing rearward, and the sub-lip 201b contacts the second sealing surface 204 facing upward. The weatherstrip 201 contacts not only the rear lower frame 17 but also the rear pillar 14.

[0082] 13 , the rear surface 14a of the rear pillar 14 and the first sealing surface 203 of the rear lower frame 17 are formed flush with each other. Therefore, the main lip 201a of the weatherstrip 201, which is provided to straddle the rear pillar 14 and the rear lower frame 17, comes into contact with the first sealing surface 203 of the rear lower frame 17 and the rear surface 14a of the rear pillar 14. At this time, because the rear surface 14a of the rear pillar 14 and the first sealing surface 203 of the rear lower frame 17 are flush with each other as described above, the main lip 201a makes continuous contact from the first sealing surface 203 of the rear lower frame 17 to the rear surface 14a of the rear pillar 14, and a good sealing condition is obtained even at the boundary between the rear pillar 14 and the rear lower frame 17.

[0083] However, the sub-lip 201b of the weatherstrip 201 does not have a portion that can come into contact with the rear pillar 14. Therefore, in the cabin 1 of this embodiment, the rear pillar cover 206 is provided with a third seal surface 210 with which the sub-lip 201b of the weatherstrip 201 comes into contact. The third seal surface 210 is curved so that it transitions inward in the width direction as it extends downward. More specifically, the third seal surface 210 is a surface that curves so that it transitions from a surface facing inward in the width direction to a surface facing upward.

[0084] Depending on the vehicle model, the rear pillar cover 206 and the rear lower frame 17 may be spaced apart in the left-right direction and may not be adjacent to each other. For example, in the cabin 1 of this embodiment, as shown in Fig. 13, a fender cover 207 that covers the rear portion of the fender 21 is disposed between the rear pillar cover 206 and the rear lower frame 17. In such a case, a fourth seal surface 211 with which the sub-lip 201b of the weatherstrip 201 comes into contact is provided on the upper part of the fender cover 207.

[0085] The second seal surface 204 and the third seal surface 210 are arranged side by side on a curve having a single radius of curvature. The second seal surface 204 and the fourth seal surface 211 are also arranged side by side on a curve having a single radius of curvature. By arranging the second seal surface 204 and the third seal surface 210, and the second seal surface 204 and the fourth seal surface 211 side by side on a curve having a single radius of curvature, the second seal surface 204, the fourth seal surface 211, and the third seal surface 210 are arranged side by side on a single curve. This prevents excessive deformation of the weatherstrip 201, which is arranged in contact with the second seal surface 204, the fourth seal surface 211, and the third seal surface 210, and thus prevents a decrease in sealing performance. Furthermore, since not only the main lip but also the sub-lip of the weatherstrip seal can be arranged side by side on a curve having a single radius of curvature, excessive deformation of the seal can be suppressed and a decrease in sealing performance can be prevented.

[0086] When the second seal surface 204 and the third seal surface 210 are arranged side by side on a curve having a single radius of curvature, the radius of curvature of the curve can be, for example, 80 to 120 mm (specifically, approximately 100 mm). By using such a radius of curvature, excessive deformation of the weatherstrip 201 can be suppressed, preventing a decrease in sealing performance.

[0087] Furthermore, in order to arrange the second seal surface 204 and the third seal surface 210 side by side on such a curve, it is necessary to make the angle (interior angle) of the joint between the rear pillar 14 and the rear lower frame 17 gentler (larger) than an angle close to a right angle. To achieve this, it is necessary to appropriately adjust the radius of curvature of both left and right ends of the second seal surface 204. This adjustment can be easily performed because the curved shape of the rear lower frame 17 can be easily adjusted as described above.

[0088] Figure 14 is a diagram showing the rear of the driver's seat 6 as seen from the front. As shown in Figure 14, a pair of side frames 205L, 205R are arranged on the left and right of a rear lower panel 200 provided below and behind the driver's seat 6. Hereinafter, the side frames 205L, 205R will be collectively referred to as side frames 205.

[0089] The lower end of the left side frame 205L is connected to the upper end of a base frame 213 provided at the left end of the rear wall portion 221 of the cabin 1. The left side frame 205L extends from the upper end of the base frame 213 toward the rear upper portion and inclined leftward. The upper end of the left side frame 205L is joined to the lower left end of the rear lower frame 17.

[0090] The lower end of the right side frame 205R is connected to the upper end of a base frame 213 provided at the right end of the rear wall portion 221 of the cabin 1. The right side frame 205R extends from the upper end of the base frame 213 toward the rear upper portion and inclined toward the right. The upper end of the right side frame 205R is joined to the lower right end of the rear lower frame 17.

[0091] That is, the left side frame 205L extends upward and inclines to the left, and the right side frame 205R extends upward and inclines to the right. That is, the pair of side frames 205L, 205R are arranged so that they widen toward the upper rear.

[0092] The right portion of left side frame 205L supports the left end of rear lower panel 200. The left end of rear lower panel 200 is supported over its entire vertical area from bottom to top by the right portion of left side frame 205L, except for the upper portion supported by support plate 208. In addition, the left portion of right side frame 205R supports the right end of rear lower panel 200. The right end of rear lower panel 200 is supported over its entire vertical area from bottom to top by the left portion of right side frame 205R, except for the upper portion supported by support plate 208.

[0093] In this way, the pair of side frames 205L, 205R support the left and right ends of the rear lower panel 200 over the entire vertical area, so that the left and right ends of the rear lower panel 200 widen toward the upper rear. This allows the rear lower panel 200 to expand the field of view to the upper left and upper right corners (both upper corners), ensuring a field of view toward the rear that passes through the upper corners of the rear lower panel 200, thereby widening the field of view to the rear.

[0094] If the pair of side frames 205L, 205R are arranged so that they widen toward the upper rear in order to widen the rear field of view, the rear frame structure will not be strong enough, and therefore the rear frame structure will need to be reinforced. Therefore, in the cabin 1 of this embodiment, the rear frame structure is reinforced as described in (1) to (4) below.

[0095] (1) The pair of side frames 205L, 205R are formed in an inverse tapered shape, with the upper end being wider in the left-right direction than the lower end.

[0096] The pair of side frames 205L, 205R described above are formed from frame material that is inverted tapered in width so that the upper end is wider in the left-right direction than the lower end connected to the base frame 213. By using a pair of side frames 205L, 205R that are inverted tapered in width in this way, the joining area with the rear lower panel 200 can be increased, and the strength of the rear frame structure can be increased.

[0097] (2) The lower end of the rear pillar 14 and the upper end of the side frame 205 are both joined to the left and right ends of the rear lower frame 17.

[0098] As shown in Fig. 14, the upper ends of the side frames 205 are joined to the left and right ends of the rear lower frame 17, and both left and right ends of the rear lower frame 17 are joined to the lower parts of the left rear pillar 14L and the right rear pillar 14R, respectively. Specifically, as shown in Fig. 15, the upper end of the right side frame 205 is joined from below to the right end 17R of the rear lower frame 17. A right rear wheel fender 21R is disposed on the left side of the right side frame 205, and the right rear pillar 14R is joined to the further left side of the right rear wheel fender 21R. In other words, the lower end of the right rear pillar 14R and the upper end of the right side frame 205R are both joined to the right end 17R of the rear lower frame 17. Although the above explanation relates to the joining structure of the right end 17R of the rear lower frame 17, at the left end 17L of the rear lower frame 17, the lower end of the left rear pillar 14L and the upper end of the left side frame 205L are both joined to the left end 17L of the rear lower frame 17.

[0099] In this way, the lower end of the rear pillar 14 and the upper end of the side frame 205 are both joined to both left and right ends of the rear lower frame 17, so that the joints between the lower end of the rear pillar 14 and the upper end of the side frame 205 are close to or adjacent to each other in the left and right direction of the rear lower frame 17. This makes it less likely for the rear lower frame 17 to bend than if the joints between the lower end of the rear pillar 14 and the upper end of the side frame 205 were farther apart in the left and right direction, making it possible to increase the strength of the rear frame structure.

[0100] It is preferable that the joint where the upper end of the side frame 205 is joined to the rear lower frame 17 and the joint where the lower part of the rear pillar 14 is joined to the rear lower frame 17 are as close as possible in the left-right direction. In other words, the most preferable joint structure is one in which the upper end of the side frame 205 is adjacent in the left-right direction to the lower part of the rear pillar 14. This can maximize the strength of the frame structure in which the side frame 205, rear lower frame 17, and rear pillar 14 are joined.

[0101] (3) As shown in FIG. 15 , the support plate 208 (see FIG. 8 ) that closes the front opening of the stepped member 202 is joined to both the side frame 205 and the rear pillar 14 .

[0102] The support plate 208 is joined to the rear pillar 14 along a first joining line 214 and is joined to the side frame 205 along a second joining line 215 .

[0103] In this way, the support plate 208 is positioned to close the front opening of the stepped member 202, and the support plate 208 is joined to both the side frame 205 and the rear pillar 14, thereby increasing the strength of the rear lower frame 17.

[0104] (4) Fenders 21 (left rear wheel fender 21L, right rear wheel fender 21R) are arranged on the left-right outside of the side frame 205, curving rearward as they extend upward. The rear ends of the fenders 21 are joined to the lower part of the rear pillar 14, and the stepped member 202 is joined to the rear ends of the fenders 21.

[0105] 15, a right rear wheel fender 21R is disposed to the left of the right side frame 205R. A third weld line 216 is provided at the rear end of the right rear wheel fender 21R, and the rear end of the right rear wheel fender 21R and the right rear pillar 14R are joined along the third weld line 216.

[0106] As shown in FIG. 16, the left end of the stepped member 202 is joined to the rear end of the left rear wheel fender 21L via a weld piece 255.

[0107] By joining the left rear wheel fender 21L to the stepped member 202 in this manner, the four members of the rear pillar 14, the side frame 205, the rear lower frame 17, and the fender 21 can be joined together with high strength.

[0108] The rear upper surface of the fender 21 is formed in an inclined shape that slopes upward as it extends outward in the left-right direction. In other words, a space that can ensure rearward visibility is formed above the rear of the fender 21 at the top of the upper surface of the fender 21, making it easy to ensure rearward visibility through this space.

[0109] In a work machine such as a tractor 2, when the left door 27L or the right door 27R is closed, the pressure in the space inside the cabin 1 temporarily increases, and this increased pressure inside the cabin 1 can cause problems such as the door 27 opening against the operator's intention, even though it was supposed to be closed. To avoid such fluctuations in air pressure inside the cabin, the cabin 1 of the present invention is provided with an exhaust system 220 that exhausts air inside the cabin 1 to the outside when the pressure (air pressure) inside the cabin 1 exceeds a predetermined pressure.

[0110] As shown in FIG. 14 , the exhaust system 220 includes a body wall disposed around the driver's seat 6, an air vent hole 222 opened in the body wall, and a watertight cover 223 (see FIG. 7 ) attached to the body wall. The body wall refers to the front wall, left and right side walls, and rear wall disposed around the driver's seat 6. Whether the exhaust system 220 is provided in the front wall, left and right side walls, or rear wall varies depending on the model. However, if the aircraft 3 has a front wall, left and right side walls, a rear wall, etc., it is preferable that the air vent hole 222 be formed in one of the walls. Note that the cabin 1 of this embodiment is exemplified as having a rear wall 221 disposed behind the driver's seat 6 as the body wall, and the air vent hole 222 is provided in the rear wall 221.

[0111] That is, the exhaust system 220 of this embodiment has a rear wall portion 221 disposed behind the driver's seat 6, and the rear wall portion 221 is provided with an air vent hole 222.

[0112] 14, the exhaust system 220 of this embodiment includes an air vent hole 222 provided in a rear wall portion 221 and a water stop cover 223 (see FIG. 7) provided on the rear wall portion 221. The rear wall portion 221 is provided with a closing plate 224 that closes the air vent hole 222.

[0113] Next, the air vent hole 222, the water stop cover 223, and the closing plate 224 that constitute the exhaust system 220 of the present invention will be described.

[0114] As shown in Figures 2 and 14, the rear wall 221 is a body wall located behind the driver's seat 6. The rear wall 221 is formed in an inclined shape that transitions rearward as it extends downward. A recess 225 that is recessed rearward and downward is formed in the upper part of the rear wall 221, and an air vent hole 222 is formed in the recess 225. By providing the air vent hole 222 in the rear rear wall 221 at the rear side of the driver's seat 6, which is the part least likely to interfere with other devices, it is possible to suppress large pressure fluctuations (sudden pressure rises) within the cabin 1 when the door is closed, without reducing operability or livability within the cabin 1.

[0115] As shown in FIG. 14, the air vent holes 222 are holes with horizontally long rectangular openings when viewed from the front, and a plurality of air vent holes 222 (four in this embodiment) are formed in the rear wall portion 221 side by side in the left-right direction.

[0116] 18 , a recess 225 that is trapezoidally recessed in a side view is formed in the rear wall 221. An inclined wall 226 that slopes upward toward the front is formed at the top of the recess 225, and an air vent hole 222 is formed in the inclined wall 226. The recess 225 is formed across a range from the left end to the right end of the rear wall 221 (a range of approximately three-quarters of the overall width in the left-right direction), allowing the air inside the cabin 1 to be released over a wide range.

[0117] By providing such an air vent hole 222 to vent air from inside the cabin 1, it is possible to prevent problems such as large pressure fluctuations (sudden pressure rises) inside the cabin when the door is closed and the door being pushed back due to large pressure fluctuations.

[0118] The closure plate 224 is a plate that can close the opening of the air vent hole 222. The closure plate 224 is made of, for example, rubber, synthetic resin, or the like. In this embodiment, the closure plate 224 is made of rubber. The upper end of the closure plate 224 is fixed to the rear wall portion 221 above the air vent hole 222. More specifically, the upper end of the closure plate 224 is fixed by means of riveting, adhesive, or the like to the inclined wall portion 226 slightly above the opening of the air vent hole 222, and covers the air vent hole 222 from the upper surface side of the inclined wall portion 226. The portion of the closure plate 224 below the fixed upper end can swing (deform) upward. When the pressure in the cabin 1 exceeds a predetermined pressure, the closure plate 224 swings upward with the upper end as a fulcrum.

[0119] When the pressure inside the cabin 1 is below a predetermined pressure, the closing plate 224 does not swing, and therefore maintains a state in which it covers the air vent hole 222 from the upper surface side of the inclined wall portion 226, closing the air vent hole 222. In other words, when the pressure inside the cabin 1 is below a predetermined pressure, the closing plate 224 closes the air vent hole 222 by its own weight. When the pressure inside the cabin 1 exceeds the predetermined pressure, the force that tries to swing the closing plate 224 rearward and upward due to the action of the pressure exceeds the force that tries to close the air vent hole 222 by the closing plate 224 by its own weight, and the closing plate 224 swings rearward and upward, opening the air vent hole 222.

[0120] The pressure (predetermined pressure) inside the cabin 1 when the closure plate 224 swings is determined according to the weight of the closure plate 224. If the weight of the closure plate 224 is large, a high pressure is required to swing the closure plate 224, whereas if the weight of the closure plate 224 is small, a low pressure may be required to swing the closure plate 224. Therefore, if a thick plate is used as the closure plate 224 or if a plate with a weight attached to the upper surface or the like of the closure plate 224 is used, the pressure to swing the closure plate 224 can be set high.

[0121] For example, if laws and regulations stipulate that the air pressure inside the cabin 1 must be set higher, by using a closing plate 224 made of a thick plate or a closing plate 224 with a weight attached, it is possible to set the air pressure inside the cabin 1, where exhaust is performed by the oscillation of the closing plate 224, higher.

[0122] In addition, by appropriately setting the weight of the closing plate 224, the closing plate 224 will not open, for example, when the air conditioner is turned on and outside air is introduced, and the cold air or warm air inside the cabin 1 will not be wasted and discharged to the outside.However, when the door is closed, the air inside the cabin 1 will be released to the outside, making it possible to suppress fluctuations (sudden rises) in the air pressure inside the cabin 1.

[0123] Furthermore, a plurality of closing plates 224 are provided corresponding to the plurality of air vent holes 222. More specifically, a plurality of closing plates 224 are provided so as to individually close the plurality of air vent holes 222. Therefore, the weight of some of the closing plates 224 of the plurality of air vent holes 222 can be made different from the weight of the remaining closing plates 224. This makes it possible to use the device in such a way that, for example, when pressure fluctuations in the cabin 1 are small, some (a small number) of the air vent holes 222 are opened, and when pressure fluctuations in the cabin 1 become large, not only some of the air vent holes 222 but also the remaining air vent holes 222 (a large number of air vent holes 222) are opened, thereby enabling air inside the cabin 1 to be exhausted individually for each of the plurality of air vent holes 222.

[0124] In this embodiment, whether the closing plate 224 swings (opens) is determined by the weight of the closing plate 224 itself, but it is also possible to measure the pressure inside the cabin 1 using a pressure gauge or the like, determine whether the measured air pressure has reached a predetermined pressure using a control unit or the like, and drive a motor or the like depending on the determination result to open the closing plate 224.

[0125] Furthermore, the closure plate 224 has a rib portion 233 extending in the left-right direction at its rear end. By forming the rib portion 233 on the closure plate 224, the rib portion 233 suppresses warping or deformation of the closure plate 224. This makes it possible to avoid the problem of the closure plate 224 being unable to reliably close the air vent hole 222 due to warping or deformation.

[0126] The water stop cover 223 is disposed so as to cover the air vent hole 222. The water stop cover 223 forms a space that is open downward between itself and the rear wall portion 221 (aircraft body wall).

[0127] 17, the water stop cover 223 has a back plate 223a, left and right side plate portions 223b, and an upper plate portion 223c. The back plate portion 223a is disposed rearward of the rear wall portion 221 (aircraft body wall) with a gap between it and the rear wall portion 221. The left and right side plate portions 223b extend forward from the left and right ends of the rear wall portion 221. The upper plate portion 223c connects the upper end of the rear wall portion 221 to the left and right side plate portions 223b.

[0128] The space formed between the water stop cover 223 and the rear wall portion 221 is covered at the top by the upper plate portion 223c, at the left and right sides by the left and right side plate portions 223b, and at the rear by the back plate portion 223a, with only the bottom being open. The open bottom portion (lower end) of the water stop cover 223 is located at a position lower than the air vent hole 222. This allows air inside the cabin 1 that has entered through the air vent hole 222 to be exhausted from a position lower than the air vent hole 222.

[0129] The reason why air is discharged from a position lower than the air vent hole 222 is that if air is discharged from a position at the same height as the air vent hole 222 or from a position higher than the air vent hole 222, rainwater and foreign matter are likely to enter the air vent hole 222 through the part of the water stop cover 223 where the air is discharged. In this regard, a structure in which air is discharged from a position lower than the air vent hole 222 makes it less likely that rainwater and foreign matter will enter. In other words, by providing a water stop cover 223 that discharges air from a position lower than the air vent hole 222, it is possible to prevent water from entering the cabin 1 through the air vent hole 222.

[0130] Furthermore, by providing the waterproof cover 223, it is possible to prevent not only water from entering the cabin 1 but also noise from outside the vehicle from entering the cabin 1.

[0131] As shown in Figure 18, the rear wall 221 has a rear plate 229 located behind the inclined wall 226. The rear plate 229 extends in the vertical direction behind the inclined wall 226. The air vent hole 222 has a first hole 230 provided in the inclined wall 226 and a second hole 231 provided in the rear plate 229. Note that while Figure 18 is a vertical cross-sectional view, the portion within the large circle shows a perspective view of the vicinity of the first hole 230 within the small circle shown in the vertical cross-sectional view.

[0132] As shown in Fig. 17 , a plurality of first holes 230 (four in this embodiment) are formed in the rear wall portion 221 and aligned in the left-right direction. A plurality of second holes 231 (four in this embodiment) are formed in the rear plate portion 229 and aligned in the left-right direction. Each of the second holes 231 is positioned to overlap with a corresponding one of the first holes 230 in a rear view. In this embodiment, the closing plate 224 is fixed to the inclined wall portion 226 above the first holes 230 and is capable of closing the first holes 230. The second holes 231 are positioned behind the first holes 230, and the rear of the second holes 231 is covered by the watertight cover 223.

[0133] In this way, by providing a rear plate portion 229 behind the inclined wall portion 226 in which the first hole 230 is provided, and covering the rear of the second hole 231 provided in the rear plate portion 229 with a watertight cover 223, it is possible to prevent water and foreign objects from entering the cabin 1 from the outside, and to suppress noise from outside the vehicle from entering the cabin.

[0134] The rear panel 229 also has a first portion 229a in which the second hole 231 is provided, and a second portion 229b that is provided below the first portion 229a and is inclined so as to move forward as it extends downward. As such, because the second portion 229b that is inclined so as to move forward as it extends downward is provided below the first portion 229a in which the second hole 231 is provided, wash water sprayed from the rear when washing the cabin is blocked by the inclined second portion 229b and cannot reach the second hole 231. This prevents wash water from entering through the second hole 231.

[0135] The rear plate portion 229 further has a third portion 229c, a fourth portion 229d, a fifth portion 229e, and a sixth portion 229f. The third portion 229c extends forward from the upper end of the first portion 229a. The front end of the third portion 229c is connected to the upper extension portion 226a, which extends upward and rearward from the upper end of the inclined wall portion 226. The fourth portion 229d bends from the lower end of the second portion 229b and extends downward and rearward. The fifth portion 229e bends from the lower end of the fourth portion 229d and extends upward and forward. The sixth portion 229f bends from the lower end of the fifth portion 229e and extends downward and frontward. The vertical position of the lower end of the water stop cover 223 overlaps with the vertical position of the fourth portion 229d. The first portion 229 a , the second portion 229 b , and the third portion 229 c are located above the lower end portion of the water stop cover 223 .

[0136] With the above configuration, the water stop cover 223 prevents most of the flush water sprayed from behind from penetrating into the water stop cover 223. Of the flush water sprayed below the lower end of the water stop cover 223, part of the water that hits the fourth portion 229d bounces off and heads upward, but the upward-headed flush water hits the second portion 229b and falls. Of the flush water sprayed below the lower end of the water stop cover 223, the water that is sprayed below the fourth portion 229d hits the fifth portion 229e and falls.

[0137] In this way, not only the second portion 229b but also the fifth portion 229e function to prevent flush water from flowing upward toward the second hole 231, thereby reliably preventing flush water from entering through the second hole 231. Furthermore, because the rear plate portion 229 is bent at multiple locations as described above, the strength of the rear plate portion 229 can be improved compared to when the rear plate portion 229 is flat.

[0138] 18 , the exhaust system 220 of this embodiment has an air flow path 232 formed therein that passes through the first hole 230, the second hole 231, and between the water stop cover 223 and the rear surface of the rear wall portion 221 to exhaust air to the outside of the cabin 1. The air flow path 232 is formed between the inclined wall portion 226 in which the first hole 230 is provided and the rear plate portion 229 in which the second hole 231 is provided, and between the rear plate portion 229 and the water stop cover 223.

[0139] Air that passes through the first hole 230 from inside the cabin 1 flows into the space between the inclined wall portion 226 and the rear plate portion 229, then passes through the second hole 231 and flows into the space between the rear plate portion 229 and the water-stop cover 223, and is discharged to the outside from between the lower end of the water-stop cover 223 and the rear plate portion 229.

[0140] In this way, the ventilation flow path 232 is formed in the space covered by the watertight cover 223. Therefore, the air inside the cabin can be exhausted to the outside while preventing water and foreign matter from entering the cabin.

[0141] It is preferable that the opening area of ​​the second hole 231 and the flow path area of ​​the ventilation flow path 232 formed between the water stop cover 223 and the rear surface of the rear wall 221 are set to be equal to or larger than the opening area of ​​the first hole 230. If the opening area of ​​the second hole 231 is smaller than the opening area of ​​the first hole 230, the amount of air that can pass through the second hole 231 will be smaller than the amount of air that can pass through the first hole 230, which could result in air stagnation. Also, if the flow path area of ​​the ventilation flow path 232 formed between the water stop cover 223 and the rear surface of the rear wall 221 is smaller than the opening area of ​​the first hole 230, the amount of air that can flow through the ventilation flow path 232 formed between the water stop cover 223 and the rear surface of the rear wall 221 will be smaller than the amount of air that can pass through the first hole 230, which could result in air stagnation.

[0142] Such air stagnation can be prevented by setting the opening area of ​​the second hole 231 and the flow path area of ​​the water stop cover 223 to be equal to or larger than the opening area of ​​the first hole 230. Therefore, air can be guided smoothly along the ventilation flow path 232 from the first hole 230 to the second hole 231 and the water stop cover 223, and the air inside the cabin 1 can be reliably exhausted to the outside.

[0143] Furthermore, the inclination angle of the closure plate 224 and the inclined wall portion 226 to which the closure plate 224 is attached with respect to the horizontal direction is preferably set to 20 to 45 degrees. If the inclination angle of the closure plate 224 and the inclined wall portion 226 with respect to the horizontal direction is set to 20 to 45 degrees in this way, even if the vehicle on which the cabin 1 is provided runs on a road surface that is inclined at an angle of 20 to 45 degrees with respect to the horizontal direction, the closure plate 224 will not be opened accidentally due to the vehicle tilting. Note that the inclination angle is not limited to 20 to 45 degrees and can be changed as appropriate.

[0144] The cabin 1 of the present invention comprises door panels 27L, 27R arranged on either side of the driver's seat 6, a left side lower beam 19L and a right side lower beam 19R (sometimes referred to as left side lower frame 19L and right side lower frame 19R) that support the rear portions of the door panels 27L, 27R from below and extend in an arc from the upper rear end to the lower front end, and a left connecting frame 20L and a right connecting frame 20R that support the front portions of the door panels 27L, 27R from below and extend forward from the lower ends of the left side lower beam 19L and right side lower beam 19R.

[0145] As shown in Figure 19, a left connecting frame 20L is provided below the front portion of the left door panel 27L (see Figure 1). A step 23 is provided to the right of the left connecting frame 20L. A step mat 236 is placed on the step 23 and the left connecting frame 20L.

[0146] Below, the joining structure between the left connecting frame 20L and the left side lower beam 19L will be explained with reference to the drawings, but the joining structure between the right connecting frame 20R and the right side lower beam 19R (not shown) is similar.

[0147] 21 , in the case of a conventional cabin 501, a connecting frame 520 that connects the side lower beam 519 to the front pillar 13 is joined by abutting from the front against the front surface of the lower end of the side lower beam 519. In this type of joining structure, there is a possibility that the joining accuracy to the side lower beam 519 will vary due to the influence of dimensional tolerances in the length of the connecting frame 520. In other words, because the connecting frame 520 is joined to the front surface of the lower end of the side lower beam 519 from the front, if variation in the length (length in the front-to-rear direction) occurs due to dimensional tolerances, then the joining accuracy will vary.

[0148] 20, in the cabin 1 of the present invention, the lower end of the left side lower beam 19L is joined to the upper surface of the rear part of the left connecting frame 20L. Although not shown, the lower end of the right side lower beam 19R is joined to the upper surface of the rear part of the right connecting frame 20R.

[0149] Because the lower end of the left side lower beam 19L (right side lower frame 19R) is joined to the upper surface of the rear part of the left connecting frame 20L (right connecting frame 20R) in this way, the joining accuracy of the connecting frame 20L (right connecting frame 20R) to the left side lower beam 19L (right side lower frame 19R) is not affected by the dimensional tolerance of the length of the connecting frame 520. Therefore, it is possible to improve the joining accuracy of the connecting frame 20L (right connecting frame 20R) to the left side lower beam 19L (right side lower frame 19R).

[0150] As shown in the enlarged portion of Figure 20 (inside the circle), the front edge of the side lower beam 19L has a curved portion 238 that is curved in an arc shape, and a straight portion 239 that extends straight from the lower end of the curved portion 238 toward the front and downward in the tangent direction of the arc of the curved portion 238. If the lower end of the curved portion 238 is indicated by point Q1, the tangent to the arc of point Q1 is X Q Below point Q1, there is a tangent line X. Q The portion along the line 239 is a straight portion, and the portion above the point Q1 is a curved portion 238.

[0151] Virtual line X in the figureR is a line that is imaginary to extend the curved portion 238 downward from point Q1. R indicates the leading edge of the left side lower beam 19L when the straight portion 239 is not included. R The straight line portion 239 (tangent line X) is in contact with the contact point Q2 where the connecting frame 20L comes into contact with the upper surface of the connecting frame 20L. Q The contact point Q3 where the lower side beam 19L comes into contact with the upper surface of the connecting frame 20L is located forward by a length ΔD. R ) and the connecting frame 20L.

[0152] In this way, the point of contact Q3 between the front edge of the left side lower beam 19L and the connecting frame 20L when the straight portion 239 is included is located further forward than the point of contact Q2 between the front edge of the left side lower beam 19L and the connecting frame 20L when the straight portion 239 is not included. Therefore, the contact area between the left side lower beam 19L and the connecting frame 20L when the straight portion 239 is included is larger than the contact area between the left side lower beam 19L and the connecting frame 20L when the straight portion 239 is not included.

[0153] Therefore, in the cabin 1 of the present invention, the area of ​​the sealed portion relative to the connecting frames 20L, 20R can be expanded forward, improving the joint strength between the side lower beams 19L, 19R and the connecting frames 20L, 20R, thereby significantly improving the strength of the side door frames.

[0154] The rear edges of the left and right lower side beams 19L and 19R are curved in an arc shape behind the straight portion 239. As a result, the distance between the leading edge and trailing edge of the lower portions of the left and right lower side beams 19L and 19R widens toward the lower ends where they are joined to the left connecting frame 20L and the right connecting frame 20R. This allows for a sufficiently wide contact area between the left and right lower side beams 19L and 19R and the left connecting frame 20L and the right connecting frame 20R. This improves the joint strength between the side lower beams 19L and 19R and the connecting frames 20L and 20R.

[0155] Furthermore, because the rear edges of the left side lower beam 19L and the right side lower beam 19R are curved in an arc shape behind the straight portion 239, a wider distance (clearance) can be secured between the rear edges and the left rear wheel 12L and the right rear wheel 12R, compared to when the rear edges are straight and parallel to the straight portion 239. This makes it possible to accommodate various types (sizes) of left rear wheels 12L and right rear wheels 12R.

[0156] In this way, according to the joining structure between the side lower beams 19L, 19R and the connecting frames 20L, 20R in the above-mentioned embodiment, it is possible to improve the joining strength between the side lower beams 19L, 19R and the connecting frames 20L, 20R while ensuring a wide distance (clearance) between the side lower beams 19L, 19R and the left rear wheel 12L and the right rear wheel 12R.

[0157] It is preferable that the boundary Q1 between the curved portion 238 and the straight portion 239 at the front edge of the left side lower beam 19L and the right side lower beam 19R be located below the height Hs of the step mat 236. In other words, it is preferable that the straight portion 239 be located below the upper surface of the step mat 236.

[0158] By positioning the straight line portion 239 below the upper surface of the step mat 236 in this way, the area of ​​the sealing portion can be increased without narrowing the distance along the left-right direction of the upper surface of the step mat 236, in other words, the width of the door when the operator OP gets in and out. As a result, the strength of the door frame can be improved without impairing ease of getting in and out.

[0159] As shown in Figures 19 and 22, the lower part of the left front pillar 13L is connected to the front end of the connecting frame 20L. The left front pillar 13L is made of a profiled pipe. As shown in Figure 23, the profiled pipe constituting the left front pillar 13L has a first portion 13a, a pair of second portions 13b, a pair of third portions 13c, and a fourth portion 13d. The first portion 13a, the second portion 13b, the third portion 13c, and the fourth portion 13d are formed as a single unit.

[0160] The first portion 13a is a surface facing outward from the cabin 1 and is formed in an arc shape. The pair of second portions 13b extend from both ends of the first portion 13a in directions approaching each other toward the inside of the cabin 1. The pair of third portions 13c extend from the respective ends of the pair of second portions 13b in directions separating from each other toward the inside of the cabin 1. The fourth portion 13d is disposed opposite the first portion 13a, and is disposed so that both widthwise ends abut against the pair of third portions 13c, respectively.

[0161] A bracket 257 is disposed on the inside (fourth portion 13d side) of the left front pillar 13L. The bracket 257 includes a bracket main body 257a, a reinforcing rib 257b, and a cylindrical body 257c. The bracket main body 257a includes a first plate portion 257a1, a second plate portion 257a2, and a third plate portion 257a3. The first plate portion 257a1, the second plate portion 257a2, and the third plate portion 257a3 are formed in a U-shape (approximately a C-shape) in a plan view. The first plate portion 257a1 extends higher than the second plate portion 257a2 and the third plate portion 257a3.

[0162] The reinforcing rib 257b is joined to the third plate portion 257a3. The reinforcing rib 257b extends higher than the second plate portion 257a2 and the third plate portion 257a3. The reinforcing rib 257b also extends higher than the first plate portion 257a1. The cylindrical body 257c is arranged so as to be surrounded on three sides by the first plate portion 257a1, the second plate portion 257a2, and the third plate portion 257a3.

[0163] 22 and 23 , the bracket 257 is disposed on the inside of the left front pillar 13L (the fourth portion 13d side) and is joined to the front lower frame 256 and the connecting frame 20L. The first plate portion 257a1 of the bracket 257 is joined to the front end portion of the connecting frame 20L, and the second plate portion 257a2 is joined to the left end portion of the front lower frame 256.

[0164] The first plate portion 257a1 is joined to one of the pair of third portions 13c of the left front pillar 13L. As described above, the first plate portion 257a1 extends higher than the second plate portion 257a2 and the third plate portion 257a3. This ensures a large joining length (joint area) between the first plate portion 257a1 and the third portion 13c. This allows the first plate portion 257a1 to be firmly joined to the left front pillar 13L.

[0165] A reinforcing rib 257b is joined to the other of the pair of third portions 13c of the left front pillar 13L. As described above, the reinforcing rib 257b extends higher than the second plate portion 257a2 and the third plate portion 257a3. This ensures a large joining length (joint area) between the reinforcing rib 257b and the third portion 13c. This allows the reinforcing rib 257b to be firmly joined to the left front pillar 13L.

[0166] As described above, the first plate portion 257a1 and the reinforcing rib 257b can be firmly joined to the left front pillar 13L, which allows the bracket 257 to be firmly joined to the left front pillar 13L. Here, the reinforcing rib 257b extends higher than the first plate portion 257a1, which increases the joining strength to the left front pillar 13L. Therefore, providing the reinforcing rib 257b can improve the joining strength of the bracket 257 to the left front pillar 13L.

[0167] An air conditioning hose 241 extending in the vertical direction is inserted through the cylindrical body 257c. The air conditioning hose 241 passes through the interior of the cylindrical body 257c and extends downward below the cabin 1. The air conditioning hose 241 extends in the vertical direction along the inner surface (the surface facing the interior of the cabin 1) of the fourth portion 13d of the left front pillar 13L. The first plate portion 257a1 and the reinforcing rib 257b are arranged to sandwich the air conditioning hose 241. Therefore, the first plate portion 257a1 and the reinforcing rib 257b can function as a guide that determines the direction of the air conditioning hose 241.

[0168] Although not shown, a bracket 257 is also arranged on the inside (the fourth portion 13d side) of the right front pillar 13R located in the right front portion of the cabin 1. The configurations (arrangements, etc.) of the right front pillar 13R, connecting frame 20R, front lower frame 256, bracket 257, and air conditioning hose 241 in the right front portion of the cabin 1 are similar to the configurations (arrangements, etc.) of the left front pillar 13L, connecting frame 20L, front lower frame 256, and air conditioning hose 241 in the left front portion of the cabin 1.

[0169] In the cabin 1 of the present invention, the front panel 31 is made of a single piece of seamless panel material, which makes the front panel 31 heavy. The load resulting from the weight of the front panel 31 must be borne by the front portion of the step 23. When the front panel is composed of upper and lower separated panels (in the case of a conventional front panel), a horizontally extending frame is provided between the upper and lower panels to support the panel material, so the load of the front panel acting on the step is not large. However, when the front panel 31 is composed of a single piece of panel material (in the case of the cabin 1 of the present invention), the load of the front panel 31 is applied to the step 23 without being distributed, so the load of the front panel acting on the step becomes large. Therefore, in the cabin 1 of the present invention, a box-shaped reinforcing bracket 240 extending in the left-right direction is joined to the front portion of the underside of the step 23 (step plate) to reinforce the step 23 (step plate) that forms the front floor of the cabin 1.

[0170] 28 , the reinforcement bracket 240 includes a left reinforcement bracket 240L and a right reinforcement bracket 240R. The left reinforcement bracket 240L is joined to the left front portion of the lower surface of the step 23. The right reinforcement bracket 240R is joined to the right front portion of the lower surface of the step 23. The shapes of the left reinforcement bracket 240L and the right reinforcement bracket 240R are symmetrical across the center line in the width direction of the cabin 1 that extends in the fore-and-aft direction.

[0171] Figure 24 shows the shape of the left reinforcing bracket 240L. As shown in the figure, the reinforcing bracket 240 is formed in a rectangular parallelepiped shape, and a cross section cut in the front-to-rear direction is rectangular. The step 23 is joined to the upper part of the reinforcing bracket 240. The front lower frame 256 (see Figure 2) is joined to the front part of the reinforcing bracket 240. In other words, the reinforcing bracket 240 is joined to both the front lower frame 256 located in front of it and the step 23 located above it, and these three members work together to support the load of the front panel 31.

[0172] As described above, the reinforcing bracket 240 is box-shaped (rectangular parallelepiped) and has a square cross section cut in the front-to-rear direction. This type of reinforcing bracket 240 has higher rigidity than a bracket shaped by simply bending a portion of a plate. Therefore, by joining this type of reinforcing bracket 240 to the front portion of the step 23, the front portion of the step 23 can be effectively reinforced, and the weight of the front panel 31 can be reliably supported by the front portion of the step 23.

[0173] As shown in Figures 24 and 25, the reinforcing bracket 240 has a bottom plate 250 disposed downward from the lower surface 23a of the step 23 at a distance. The bottom plate 250 is formed in a generally rectangular plate shape that is long in the left-right direction. A front side plate 242F and a rear side plate 242R that extend in the up-down direction are provided at the front and rear ends of the bottom plate 250. A top plate 243 is provided between the upper end of the front side plate 242F and the upper end of the rear side plate 242R. In other words, the reinforcing bracket 240 is formed into a rectangular tube shape that extends in the left-right direction by the bottom plate 250, the front side plate 242F, the rear side plate 242R, and the top plate 243. Note that the reinforcing bracket 240 of this embodiment has the top plate 243, and a cross section cut along the front-to-rear direction is rectangular. The upper surface of the top plate 243 is joined to the lower surface 23a of the step 23.

[0174] However, the reinforcing bracket 240 may not have the top plate 243. In this case, the reinforcing bracket 240 is formed in a U-shape (approximately a C-shape) whose cross section cut along the front-rear direction opens upward. In this case, the upper parts of the reinforcing bracket 240 other than the top plate 243 (for example, the upper ends of the front plate 242F and the rear plate 242R) are joined to the underside 23a of the step 23.

[0175] As shown in Figures 24, 25, and 27, a vertical plate 244L extending upward toward the underside 23a is formed at the right end of the bottom plate 250 of the left reinforcement bracket 240L. The vertical plate 244L is provided to close the opening facing right of the rectangular tubular left reinforcement bracket 240L. As shown in Figure 27, a vertical plate 244R extending upward toward the underside 23a is formed at the left end of the bottom plate 250 of the right reinforcement bracket 240R. The vertical plate 244R of the right reinforcement bracket 240R is provided to close the opening facing left of the rectangular tubular right reinforcement bracket 240R. In this way, the vertical plate 244L closes the right end of the left reinforcement bracket 240L, and the vertical plate 244R closes the left end of the right reinforcement bracket 240R. Hereinafter, the vertical plates 244L and 244R may be collectively referred to as the vertical plates 244.

[0176] As described above, the left reinforcing bracket 240L has a top plate 243 at its upper part, a bottom plate 250 at its lower part, a front side plate 242F at its front part, a rear side plate 242R at its rear part, and a vertical plate 244L at its right part. The left part of the left reinforcing bracket 240L is connected to the connecting frame 20L (see FIGS. 2 and 27). As a result, a space (hereinafter referred to as the bracket internal space) is formed at the front left part of the step 23, surrounded by the top plate 243, bottom plate 250, front side plate 242F, rear side plate 242R, and vertical plate 244L of the left reinforcing bracket 240L and the connecting frame 20L.

[0177] The right reinforcing bracket 240R has a top plate 243 at its upper part, a bottom plate 250 at its lower part, a front plate 242F at its front part, a rear plate 242R at its rear part, and a vertical plate 244R at its left part. The right part of the right reinforcing bracket 240R is connected to the connecting frame 20R (see FIG. 2). As a result, a space (hereinafter referred to as the bracket internal space) is formed at the front right part of the step 23, surrounded by the top plate 243, bottom plate 250, front plate 242F, rear plate 242R, and vertical plate 244R of the right reinforcing bracket 240R and the connecting frame 20R.

[0178] By forming the above-mentioned bracket internal space, vibrations and sounds transmitted from below the reinforcing brackets 240L, 240R toward the cabin are attenuated in the internal space, thereby achieving vibration suppression and sound insulation effects.

[0179] The vertical plate 244 of the left reinforcing bracket 240L and the vertical plate 244 of the right reinforcing bracket 240R described above are provided with reinforcing ribs 245. The reinforcing ribs 245 include a left reinforcing rib 245L that connects the right vertical plate 244L of the left reinforcing bracket 240L to the underside 23a of the step 23, and a right reinforcing rib 245R that connects the left vertical plate 244R of the right reinforcing bracket 240R to the underside 23a of the step 23. The left reinforcing rib 245L is arranged to extend rightward from the vertical plate 244L, and the right reinforcing rib 245R is arranged to extend leftward from the vertical plate 244R.

[0180] The reinforcing ribs 245 are plate members that are approximately triangular when viewed from the front or rear, and two of them are arranged, one at the front end and one at the rear end of the vertical plate 244. By providing such reinforcing ribs 245, the rigidity of the reinforcing brackets 240L, 240R is further improved, and the support strength of the step 23 against the front panel 31 can be further improved.

[0181] As shown in Figures 25 and 26, the cabin 1 is equipped with an air conditioning hose 241 that circulates refrigerant between the cabin 1 and the air conditioner 26 (see Figure 1). The air conditioning hose 241 is arranged along a path that passes through the outside of the reinforcing bracket 240. Therefore, the air conditioning hose 241 is not arranged in the internal spaces of the left reinforcing bracket 240L and the right reinforcing bracket 240R. This eliminates the need to provide openings in the left reinforcing bracket 240L and the right reinforcing bracket 240R for passing the air conditioning hose 241 through. Therefore, the vibration suppression effect and sound insulation effect achieved by providing the internal spaces are not hindered by the air conditioning hose 241.

[0182] As shown in Figure 25, the left front pillar 13L is provided to the left front of the left reinforcing bracket 240L. The left front pillar 13L is a hollow, irregular-shaped pipe through which an air conditioning hose 241 is inserted. The air conditioning hose 241 exits the pipe from the lower end of the left front pillar 13L, extends to the right in front of the reinforcing bracket 240L through a path provided below the rear lower frame 17, passes to the right of a vertical plate 244 of the left reinforcing bracket 240L, and is guided through a cutout 100 (described later) to a heat exchanger such as a radiator provided inside the hood.

[0183] Although not shown, the air conditioning hose 241 can also be inserted inside the right front pillar 13R. In this case, the air conditioning hose 241 exits the pipe from the lower end of the right front pillar 13R, extends leftward through a path provided in front of the reinforcing bracket 240 and below the rear lower frame 17, passes to the left of the vertical plate 244 of the right reinforcing bracket 240R, and is guided through a cutout 100 (described later) to a heat exchanger such as a radiator provided inside the hood.

[0184] When the air conditioning hose 241 is routed along a path that passes outside the reinforcing bracket 240, the strength (rigidity) of the reinforcing bracket 240 can be increased compared to when the air conditioning hose is provided inside the reinforcing bracket. For example, when a structure for routing the air conditioning hose is provided inside the reinforcing bracket, it becomes difficult to provide ribs (such as the internal rib 249 described below) inside the reinforcing bracket 240 for the length of the air conditioning hose, which may reduce the rigidity of the reinforcing bracket. In this regard, when the air conditioning hose 241 is routed outside the reinforcing bracket 240, it becomes easier to provide the internal rib 249 inside the reinforcing bracket 240, and the reinforcing bracket 240 can be configured solely for reinforcement, thereby further improving the strength of the step 23.

[0185] As shown in FIG. 5 , the cabin 1 of this embodiment includes a front panel 31 having a cutout 100 in the lower center in the left-right direction. A gate-shaped opening frame 102 (see FIG. 4 ) is attached along the cutout 100. The opening frame 102 is shaped to fit the opening of the cutout 100 and is bonded to the periphery of the opening, making it a member with high support strength. Therefore, if a member that connects the above-mentioned reinforcing bracket 240 and the opening frame 102 to each other is provided, the support strength of the step 23 can be further improved. Therefore, in the cabin 1 of this embodiment, a connecting frame 246 is provided between the opening frame 102 and the reinforcing bracket 240 to integrally connect the opening frame 102 and the reinforcing bracket 240.

[0186] As shown in FIG. 25 , the connecting frame 246 is formed integrally with the reinforcing bracket 240. Specifically, the connecting frame 246 is formed rising upward from the widthwise inner end of the top plate 243 of the reinforcing bracket 240. The end face of the connecting frame 246 facing the cutout 100 (the face with the lead line 246 attached) is formed in a triangular shape. Furthermore, the end face of the connecting frame 246 facing the cutout 100 is joined to the rear surface of the opening frame 102 provided along the cutout 100 of the front panel 31. By providing such a connecting frame 246, the reinforcing bracket 240 and the opening frame 102 are integrally connected, thereby further improving the support strength provided by the reinforcing bracket 240.

[0187] As shown in FIG. 28 , a plurality of mounting portions 248 are provided on the underside of the reinforcing bracket 240 at intervals in the front-to-rear direction. The mounting portions 247 are provided with mounting rubber or the like. In this embodiment, the mounting portions 248 are through-holes through which bolts or the like can be inserted, and the mounting portions 247 can be attached to the reinforcing bracket 240 using bolts or the like. In the illustrated example, two sets of mounting portions 248, each having two through-holes in the left and right directions, are provided on the underside of the reinforcing bracket 240 at different positions in the front-to-rear direction. By providing a plurality of mounting portions 248 at intervals in the front-to-rear direction in this manner, the mounting positions of the mounting portions 247 can be changed in the front-to-rear direction, and the installation position of the cabin can be shifted forward or backward.

[0188] As a method for increasing the rigidity of the reinforcing bracket 240, an internal rib 249 can also be provided inside the reinforcing bracket 240. Figure 29 shows an example of a reinforcing bracket 240 provided with an internal rib 249.

[0189] 29 , the internal ribs 249 are formed on the upper surface of the bottom plate 250 along the left-right and front-rear directions. The internal ribs 249 include a first rib 249a disposed between the front plate 242F and the rear plate 242R so as to extend along the front-rear direction, and a second rib 249b disposed between the front plate 242F and the rear plate 242R so as to be parallel to the front plate 242F and the rear plate 242R. In this embodiment, the internal ribs 249 form a lattice-like structure by combining the first ribs 249a and the second ribs 249b vertically and horizontally. The first ribs 249a and the second ribs 249b are used to integrate the bottom plate 250, the front plate 242F, the rear plate 242R, and the vertical plate 244 (and the top plate 243 in this embodiment), thereby improving the rigidity of the reinforcing bracket 240. By providing such internal ribs 249 inside the reinforcing bracket 240, the internal ribs 249 further improve the rigidity of the reinforcing bracket 240, and the supporting strength of the step 23 can be further improved.

[0190] A preferred embodiment of the present invention provides a cabin 1 as described in the following items.

[0191] (Item A1) A cabin 1 comprising a rear panel 32 arranged behind the driver's seat 6, a rear lower frame 17 arranged below the rear panel 32, and rear pillars 14 arranged on the left and right sides of the rear panel 32, wherein the rear lower frame 17 is composed of a stepped member 202 that protrudes rearward in a stair-like manner, and the central portion 17C of the cabin 1 is curved downward relative to both left and right ends 17L, 17R.

[0192] According to the cabin 1 according to item A1, the angle formed between the rear pillar 14 and the rear lower frame 17 can be made greater than 90 degrees. Even if a sealing member (weather strip) is provided for the rear panel 32 supported by the rear pillar 14 and the rear lower frame 17, excessive deformation of the sealing member can be prevented, thereby suppressing deterioration of sealing performance. Furthermore, by making the angle formed between the rear pillar 14 and the rear lower frame 17 greater than 90 degrees, rearward visibility from the rear panel 32 is improved. Furthermore, because the rear lower frame 17 is made of the stepped member 202, it is easier to adjust the degree of curvature of the rear lower frame 17 compared to when the rear lower frame is made of a highly rigid square tube, and this makes it easier to adjust the angle formed between the rear pillar 14 and the rear lower frame 17.

[0193] (Item A2) The cabin 1 described in Item A1 includes a rear lower glass (rear lower panel 200) arranged behind and below the driver's seat 6, and a support plate 208 supporting an upper portion of the rear lower glass (rear lower panel 200), the support plate 208 being arranged so as to close an opening in front of the stepped member 202.

[0194] According to the cabin 1 relating to item A2, the support plate 208 is positioned so as to close the opening in front of the stepped member 202, so that the rear lower frame 17 has a structure with a closed cross section that combines the stepped member 202 and the support plate 208, thereby greatly improving strength (rigidity).

[0195] (Item A3) The cabin 1 according to Item A1 or A2, further comprising: a weatherstrip 201 arranged between the rear panel 32 and the rear lower frame 17, and between the rear panel 32 and the rear pillar 14, wherein the stepped member 202 has a first sealing surface 203 facing rearward and a second sealing surface 204 facing upward, the weatherstrip 201 being of a double lip type including a main lip 201 a and a sub-lip 201 b, and being attached to the rear panel 32 in a state where the main lip 201 a contacts the first sealing surface 203 and the sub-lip 201 b contacts the second sealing surface 204 between the rear panel 32 and the rear lower frame 17.

[0196] According to the cabin 1 relating to item A3, even if rainwater passes over the sub-lip 201b of the weatherstrip 201 and penetrates into the interior of the weatherstrip 201, the penetrated rainwater can be quickly allowed to flow downward through the space formed between the main lip 201a and the sub-lip 201b.

[0197] (Item A4) The cabin 1 according to Item A3, wherein the rear pillar 14 is provided with a rear pillar cover 206 that covers a rear surface of the rear pillar 14, the rear pillar cover 206 has a third sealing surface 210 (at an end facing the rear panel 32) with which the sub-lip 201b of the weatherstrip 201 comes into contact, the rear surface of the rear pillar 14 and the first sealing surface 203 of the rear lower frame 17 are formed flush with each other, and the second sealing surface 204 and the third sealing surface 210 are provided side by side on a curve having a single radius of curvature.

[0198] According to the cabin 1 relating to item A4, not only the main lip 201a but also the sub-lip 201b of the seal of the weatherstrip 201 can be arranged side by side on a curve having a single radius of curvature, thereby preventing excessive deformation of the weatherstrip 201 and preventing a decrease in sealing performance.

[0199] (Item A5) The cabin 1 described in Item A3 or A4, wherein a fender cover 207 covering the rear portions of the fenders 21L, 21R is provided below the rear pillar 14, the fender cover 207 has a fourth seal surface 211 (at an end facing the rear panel 32) with which the sub-lip 201b of the weatherstrip 201 comes into contact, the rear surface of the fender cover 207 and the first seal surface 203 of the rear lower frame 17 are formed flush with each other, and the second seal surface 204 and the fourth seal surface 211 are arranged side by side on a curve having a single radius of curvature.

[0200] According to the cabin 1 relating to item A5, not only the main lip 201a but also the sub-lip 201b of the seal of the weatherstrip 201 can be arranged side by side on a curve having a single radius of curvature, thereby preventing excessive deformation of the weatherstrip 201 and preventing a decrease in sealing performance.

[0201] (Item A6) The cabin 1 according to any one of Items A3 to A5, wherein the rear lower frame 17 has a tip surface 202a that protrudes rearward, a lower surface 202b that is formed adjacent to a front portion of the tip surface 202a and faces downward, the second seal surface 204 that is formed adjacent to the front portion of the tip surface 202a and faces upward, the first seal surface 203 that is formed adjacent to a front portion of the second seal surface 204 and faces rearward, and an upper surface 202c that is formed adjacent to a front portion of the first seal surface 203 and faces upward, wherein the upper surface 202c and the lower surface 202b are inclined surfaces that slope downward toward the rear, and the upper surface 202c is drawn so that an angle of inclination with respect to the horizontal direction is larger than that of the lower surface 202b.

[0202] According to the cabin 1 relating to item A6, the upper surface 202c of the stepped member 202 (rear lower frame 17) is drawn so that the angle of inclination relative to the horizontal direction is greater than that of the lower surface 202b. Therefore, by forming the upper surface 202c that slopes rearward by drawing, it is possible to ensure rearward visibility, particularly downward visibility, from the driver (operator OP) through the rear panel 32.

[0203] (Item A7) The cabin 1 according to any one of Items A1 to A6, wherein the rear lower frame 17 has a central portion 17C curved at a first radius of curvature R1 and end portions 17L, 17R curved at a second radius of curvature R2, and the first radius of curvature R1 and the second radius of curvature R2 are different from each other.

[0204] According to the cabin 1 relating to item A7, the radius of curvature R2 of the central portion 17C and the ends 17L, 17R of the rear lower frame 17 can be adjusted appropriately to smoothly connect the rear lower frame 17 to the rear pillar 14.

[0205] (Item A8) The cabin 1 according to Item A7, wherein the first curvature radius R1 is larger than the second curvature radius R2.

[0206] According to the cabin 1 relating to item A8, by making the first radius of curvature R1 of the central portion 17C of the rear lower frame 17 larger than the second radius of curvature R2 of the end portions 17L and 17R, the rear lower frame 17 can be smoothly connected to the rear pillar 14.

[0207] (Item B1) A cabin 1 comprising a rear lower panel 200 arranged at the rear lower part of the driver's seat 6, and a pair of side frames 205L, 205R arranged on the left and right sides of the rear lower panel 200, wherein the pair of side frames 205L, 205R are arranged so that they widen towards the upper rear, while supporting the left and right ends of the rear lower panel 200 over the entire vertical range.

[0208] According to the cabin 1 according to item B1, the pair of side frames 205L, 205R are formed so as to widen toward the upper rear, thereby ensuring a wide rearward field of view that passes through both upper corners of the rear lower panel 200. In addition, the pair of side frames 205L, 205R support the left and right ends of the rear lower panel 200 over the entire vertical area, which makes it possible to increase the strength of the rear frame structure.

[0209] (Item B2) The cabin 1 according to Item B1, further comprising: a rear lower frame 17 arranged along the upper end of the rear lower panel 200; a rear panel 32 arranged above the rear lower frame 17; and rear pillars 14L, 14R arranged to the left and right of the rear panel 32, wherein upper ends of the side frames 205 are joined to left and right ends 17L, 17R of the rear lower frame 17, and both left and right ends 17L, 17R of the rear lower frame 17 are each joined to a lower portion of the rear pillar 14.

[0210] According to the cabin 1 relating to item B2, the upper end of the side frame 205 is joined to the left and right ends 17L, 17R of the rear lower frame 17, and both left and right ends 17L, 17R of the rear lower frame 17 are each joined to the lower part of the rear pillar 14, so that the side frame 205 and the rear pillar 14 are positioned close to each other, thereby improving the strength of the frame structure of the cabin 1.

[0211] (Item B3) The cabin 1 according to item B1 or B2, wherein an upper end of the side frame 205 is adjacent to a lower portion of the rear pillar 14 in the left-right direction.

[0212] According to the cabin 1 relating to item B3, the upper end of the side frame 205 and the lower part of the rear pillar 14 are located adjacent to each other in the left-right direction, so that the side frame 205, the rear lower frame 17, and the rear pillar 14 are integrally joined to form a frame structure, which makes the frame structure less susceptible to deformation and greatly improves the strength of the frame structure.

[0213] (Item B4) A cabin 1 according to Item B2 or B3, comprising a rear lower glass (rear lower panel 200) arranged below and behind the driver's seat 6, and a support plate 208 supporting an upper portion of the rear lower glass (rear lower panel 200), wherein the rear lower frame 17 has a stepped member 202 that protrudes rearward in a stair-like manner, and the support plate 208 is arranged to close an opening in front of the stepped member 202 and is joined to both the side frame 205 and the rear pillar 14.

[0214] According to the cabin 1 relating to item B4, the support plate 208 is positioned so as to close the opening in front of the stepped member 202, and the support plate 208 is joined to both the side frame 205 and the rear pillar 14, so that the strength of the rear lower frame 17 can be increased and cutting and joining operations can be easily performed.

[0215] (Item B5) A cabin 1 described in Item B4, in which fenders 21L, 21R that curve rearward as they extend upward are arranged on the left-right outer side of the side frame 205, the rear ends of the fenders 21L, 21R are joined to the lower part of the rear pillar 14, and the stepped member 202 is joined to the rear ends of the fenders 21L, 21R.

[0216] According to the cabin 1 relating to item B5, the fenders 21L and 21R, which are provided further outward in the left-right direction from the side frame 205, which is joined to the support plate 208, are joined to the stepped member 202, thereby enabling the four members of the rear pillar 14, the side frame 205, the rear lower frame 17, and the fenders 21L and 21R to be joined with high strength.

[0217] (Item B6) The cabin 1 according to any one of Items B1 to B5, wherein the rear upper surfaces of the fenders 21L, 21R are formed in an inclined shape that slopes upward as it extends outward in the left-right direction.

[0218] According to the cabin 1 according to item B6, a space capable of ensuring rearward visibility can be formed above the rear of the fenders 21L, 21R, making it easy to ensure rearward visibility.

[0219] (Item C1) A cabin (1) comprising a body wall arranged around a driver's seat (6), an air vent hole (222) opened in the body wall, and a water stop cover (223) attached to the body wall, the water stop cover (223) being positioned to cover the air vent hole (222) and forming a space that is open downward between the body wall and the water stop cover.

[0220] Cabin 1 according to item C1 can prevent problems that have traditionally been a problem in four-poster cabins, such as large fluctuations in cabin pressure when the doors are closed and the doors being pushed back due to such large pressure fluctuations, by venting air from the cabin using air vent hole 222. Furthermore, by providing watertight cover 223, it is possible to prevent water from entering the vehicle interior through air vent hole 222.

[0221] (Item C2) The cabin 1 according to Item C1, wherein the aircraft body wall has a rear wall portion 221 arranged behind the driver's seat 6, and the air vent hole 222 is provided in the rear wall portion 221.

[0222] According to the cabin 1 relating to item C2, the air vent hole 222 can be provided at the rear of the driver's seat 6, which is the position that is least likely to interfere with other devices, thereby preventing a decrease in operability and livability within the cabin 1.

[0223] (Item C3) The cabin 1 according to Item C2, wherein the rear wall portion 221 is provided with a closing plate 224 that closes the air vent hole 222, and the closing plate 224 opens the air vent hole 222 when the pressure inside the cabin 1 exceeds a predetermined pressure.

[0224] According to the cabin 1 relating to item C3, the closing plate 224 is provided so as to be able to close the air vent hole 222, so that splashes of high-pressure cleaning water and foreign objects can be reliably prevented from entering the vehicle interior through the air vent hole 222.

[0225] (Item C4) The cabin 1 according to Item C3, wherein the air vent holes 222 are provided in a plurality of rows aligned in the left-right direction, and the closing plates 224 are provided in a plurality of rows so as to individually close the plurality of air vent holes 222.

[0226] According to the cabin 1 according to item C4, the plurality of air vent holes 222 can be individually closed by the closing plate 224 in accordance with the magnitude of the pressure fluctuation inside the cabin 1. For example, when the pressure fluctuation inside the cabin 1 is small, a small number of air vent holes 222 can be opened, and when the pressure fluctuation inside the cabin 1 becomes large, a large number of air vent holes 222 can be opened, thereby enabling the pressure inside the cabin 1 to be finely adjusted.

[0227] (Item C5) The cabin 1 described in Item C3 or C4, wherein the rear wall portion 221 has an inclined wall portion 226 that transitions rearward as it extends downward, the inclined wall portion 226 is provided with the air vent hole 222, and the closing plate 224 covers the air vent hole 222 from the upper surface side of the inclined wall portion 226.

[0228] According to the cabin 1 according to item C5, the weight of the closing plate 224 itself can be used to reliably close the air vent hole 222. Furthermore, by changing the weight of the closing plate 224 itself, it is also possible to set the degree to which the air pressure inside the cabin 1 must fluctuate before the closing plate 224 opens. Therefore, for example, the closing plate 224 will not open just by operating the air conditioner to introduce outside air, and cold or warm air will not be exhausted unnecessarily, but when the door is closed, outside air can be released, making it possible to suppress fluctuations in air pressure inside the cabin 1.

[0229] (Item C6) The cabin 1 described in Item C5, wherein the rear wall portion 221 has a rear plate portion 229 disposed rearward of the inclined wall portion 226 and extending in the vertical direction, the air vent hole 222 has a first hole 230 provided in the inclined wall portion 226 and a second hole 231 provided in the rear plate portion 229, and the closing plate 224 is capable of closing the first hole 230.

[0230] According to the cabin 1 relating to item C6, it is possible to guide the air in the cabin 1 to the watertight cover 223 via the first hole 230 provided in the inclined wall portion 226 and the second hole 231 provided in the rear panel portion 229, and the watertight cover 223 prevents high-pressure cleaning water from entering the cabin 1 and noise from outside the vehicle from entering the cabin 1.

[0231] (Item C7) A cabin 1 according to any one of Items C3 to C6, wherein the upper end of the closure plate 224 is fixed to the rear wall portion 221 above the air vent hole 222, and swings upward around the upper end as a fulcrum when the pressure inside the cabin 1 exceeds a predetermined pressure.

[0232] According to the cabin 1 according to item C7, by fixing the upper end of the closing plate 224 to the rear wall portion 221 located above the air vent hole 222, it is possible to reliably close the first hole 230 by utilizing the weight of the closing plate 224 itself. Also, by changing the weight of the closing plate 224 itself, it is possible to adjust the predetermined pressure at which the closing plate 224 opens. Therefore, for example, the closing plate 224 will not open just by operating the air conditioner to introduce outside air, and cold or warm air will not be exhausted unnecessarily. However, when the door is closed, the closing plate 224 can be opened and closed in such a way that outside air can be released, thereby suppressing fluctuations in air pressure inside the cabin 1.

[0233] (Item C8) A cabin 1 described in Item C6, or Item C7 which cites Item C6, in which an air flow path 232 is formed that discharges air to the outside of the cabin 1 through the first hole 230, the second hole 231, and between the water-stop cover 223 and the rear surface of the rear wall portion 221.

[0234] According to the cabin 1 relating to item C8, an air vent passage 232 is formed that discharges air to the outside of the cabin 1 through the watertight cover 223, so that the air inside the cabin 1 can be discharged to the outside while preventing the intrusion of water or foreign matter.

[0235] (Item C9) The cabin 1 described in Item C8, wherein the opening area of ​​the second hole 231 and the flow path area of ​​the ventilation flow path 232 formed between the water stop cover 223 and the rear surface of the rear wall portion 221 are set to be equal to or larger than the opening area of ​​the first hole 230.

[0236] According to the cabin 1 relating to item C9, the flow path area of ​​the second hole 231 and the ventilation flow path 232 of the water-tight cover 223 is set to be greater than or equal to the flow path area of ​​the first hole 230, so that air can be guided along the ventilation flow path 232 from the first hole 230 to the second hole 231 and the water-tight cover 223 without stagnating, and the air inside the cabin 1 can be reliably exhausted to the outside.

[0237] (Item C10) A cabin 1 described in item C5, or any of items C6 to C9 that cite item C5, in which the inclination angle of the closure plate 224 and the inclined wall portion 226 to which the closure plate 224 is attached relative to the horizontal direction is 20 to 45 degrees.

[0238] According to the cabin 1 relating to item C10, even if the vehicle on which the cabin 1 is installed travels on a road surface that is inclined at an angle of 20 to 45 degrees from the horizontal, the closing plate 224 will not be opened accidentally due to the vehicle's tilted posture.

[0239] (Item C11) The cabin 1 according to any one of items C3 to C10, wherein the closure plate 224 has a rib portion 233 at a rear end thereof that extends along the left-right direction.

[0240] According to the cabin 1 relating to item C11, a rib portion 233 extending in the left-right direction is formed on the closure plate 224, so that the rib portion 233 suppresses warping and deformation of the closure plate 224, thereby avoiding the problem that the air vent hole 222 cannot be closed reliably due to a warped or deformed closure plate 224.

[0241] (Item C12) A cabin 1 described in Item C6, or any of Items C7 to C11 that cite Item C6, in which the rear plate portion 229 has a first portion 229a in which the second hole 231 is provided, and a second portion 229b that is provided below the first portion 229a and is inclined so as to transition forward as it extends downward.

[0242] According to the cabin 1 relating to this item C12, a first portion 229a in which a second hole 231 is provided and a second portion 229b which is provided below the first portion 229a and is inclined so as to move forward as it goes downward are formed. Therefore, even if splashes of high-pressure cleaning water enter from the lower end of the water-stop cover 223, the splashes will not reach the inside of the cabin 1 because the air flow path 232 is bent between the first portion 229a and the second portion 229b.

[0243] (Item D1) A cabin 1 comprising a door panel 27 arranged to the side of a driver's seat 6, a side lower beam 19 that supports the rear of the door panel 27 from below and extends in an arc from the upper rear end to the lower front end, and a connecting frame 20 that supports the front of the door panel 27 from below and extends forward from the lower end of the side lower beam 19, wherein the lower end of the side lower beam 19 is joined to the upper surface of the rear of the connecting frame 20.

[0244] According to the cabin 1 according to item D1, the lower end of the side lower beam 19 is joined to the upper surface of the rear part of the connecting frame 20, so there is no variation in the joining accuracy to the side lower beam 19 due to the influence of dimensional tolerances in the length of the connecting frame 20. This makes it possible to improve the joining accuracy between the members that make up the door opening.

[0245] (Item D2) The cabin 1 described in Item D1, wherein the front edge of the side lower beam 19 has a curved portion 238 curved in an arc shape and a straight portion 239 extending in a straight line from the lower end of the curved portion 238 toward the front and downward in a tangent direction to the arc of the curved portion 238.

[0246] According to the cabin 1 relating to item D2, a straight portion 239 is provided at the front edge of the side lower beam 19, extending linearly in the tangent direction of the arc of the curved portion 238. Therefore, compared to conventional cabins in which the lower end of the side lower beam 19 is formed only by the curved portion 238, the area of ​​the sealing portion relative to the connecting frame 20 can be expanded forward, and the joining strength between the side lower beam 19 and the connecting frame 20 can be improved.

[0247] (Item D3) The cabin 1 according to Item D2, wherein the rear edge of the side lower beam 19 is curved in an arc shape behind the straight portion 239.

[0248] According to the cabin 1 relating to item D3, the rear edge of the side lower beam 19 is curved in an arc shape behind the straight portion 239, so that it can accommodate various types of tires and a large area of ​​sealing portion can be provided between it and the straight portion 239.

[0249] (Item D4) The cabin 1 according to any one of Items D1 to D3, wherein the distance between the leading edge and the trailing edge of the lower portion of the side lower beam 19 increases toward the lower end portion joined to the connecting frame 20.

[0250] According to the cabin 1 relating to item D4, the distance between the leading edge and the trailing edge of the lower part of the side lower beam 19 increases toward the lower end where the lower part is joined to the connecting frame 20, so that the area of ​​the sealing portion can be made sufficiently large, and the strength of the door frame can be greatly improved.

[0251] (Item D5) The cabin 1 according to items D2 to D4, wherein a step mat 236 is provided on the upper part of the connecting frame 20, and the straight portion 239 is provided below an upper surface of the step mat 236.

[0252] According to the cabin 1 according to item D5, the linear portion 239 is disposed below the upper surface of the step mat 236, so that the area of ​​the sealing portion can be increased without narrowing the distance along the left-right direction of the upper surface of the step mat 236, in other words, the width of the door when the driver (operator OP) gets in and out. As a result, the strength of the door frame can be improved without impairing ease of getting in and out.

[0253] (Item E1) Cabin 1 comprising a driver's seat 6, a front panel 31 arranged in front of the driver's seat 6, and a step plate (step 23) arranged below the driver's seat 6 and constituting the floor of the cabin 1, and a box-shaped reinforcing bracket 240 extending in the left-right direction is joined to the front part of the underside of the step plate (step 23).

[0254] According to the cabin 1 relating to item E1, by providing such a reinforcing bracket 240 on the step 23, the front part of the step 23 can be reinforced, and the load of the front panel 31 can be reliably supported by the step 23.

[0255] (Item E2) The cabin 1 according to Item E1, wherein the reinforcing bracket 240 has a rectangular cross section cut in the front-rear direction.

[0256] According to the cabin 1 relating to item E2, the cross section of the reinforcing bracket 240 cut in the fore-and-aft direction is square, so the step 23 can be reinforced with the reinforcing bracket 240, which has a strong rigidity due to its shape, and the support strength of the step 23 can be improved.

[0257] (Item E3) The cabin 1 according to Item E1 or E2, wherein the reinforcing bracket 240 has a rectangular parallelepiped shape.

[0258] According to the cabin 1 relating to item E3, the reinforcing bracket 240 has a rectangular parallelepiped shape that can ensure high rigidity, so that the support strength of the step 23 can be reliably improved.

[0259] (Item E4) The cabin 1 according to any one of Items E1 to E3, wherein an air conditioning hose 241 that circulates refrigerant between the cabin 1 and an air conditioner is arranged along a path that passes outside the reinforcing bracket 240.

[0260] According to the cabin 1 relating to item E4, the air conditioning hose 241 is arranged in a path that passes through the outside of the reinforcing bracket 240, so there is no need to provide a structure (opening, notch, etc.) inside the reinforcing bracket 240 for passing the air conditioning hose 241 through, and the reinforcing bracket 240 can be structured solely for reinforcement, making it possible to further improve the support strength of the step 23.

[0261] (Item E5) A cabin 1 described in any one of items E1 to E4, in which the reinforcing bracket 240 has a bottom plate 250 arranged at a distance below the lower surface 23a (lower surface 23a of the step 23), and a vertical plate 244 extending from the bottom plate 250 toward the lower surface 23a, and in which a reinforcing rib 245 is provided to connect the vertical plate 244 and the lower surface 23a.

[0262] According to the cabin of item E5, the stiffness of the reinforcing bracket 240 is further improved by the reinforcing rib 245, and the support strength of the step 23 can be further improved.

[0263] (Item E6) The cabin 1 described in any one of Items E1 to E5, wherein the reinforcing bracket 240 includes a left reinforcing bracket 240L joined to a left portion of the underside 23a and a right reinforcing bracket 240R joined to a right portion of the underside 23a, and the reinforcing rib 245 includes a left reinforcing rib 245L connecting a right vertical plate 244L of the left reinforcing bracket 240L to the underside 23a, and a right reinforcing rib 245R connecting a left vertical plate 244R of the right reinforcing bracket 240R to the underside 23a.

[0264] According to the cabin 1 relating to item E6, a left reinforcing bracket 240L joined to the left portion of the lower surface 23a and a right reinforcing bracket 240R joined to the right portion of the lower surface 23a are provided, so that both the left and right sides of the step 23 can be reinforced in the same manner, and the support strength of the front panel 31 by the step 23 can be improved evenly in the left-right direction.

[0265] (Item E7) The cabin 1 according to any one of items E1 to E6, wherein an internal rib 249 is provided inside the reinforcing bracket 240, connecting the inner wall of the reinforcing bracket 240 and the lower surface 23a.

[0266] According to the cabin 1 according to item E7, the internal rib 249 further improves the rigidity of the reinforcing bracket 240, and the support strength of the step 23 can be further improved.

[0267] (Item E8) A cabin 1 described in any one of items E1 to E7, wherein the front panel 31 has a cutout portion 100 in the lower center in the left-right direction, an opening frame 102 is arranged in the cutout portion 100 and is shaped to fit the opening of the cutout portion 100 and is adhered to the periphery of the opening, and a connecting frame 246 is provided between the opening frame 102 and the reinforcing bracket 240 to connect the opening frame 102 and the reinforcing bracket 240 together.

[0268] According to the cabin 1 according to item E8, the reinforcing bracket 240 and the opening frame 102 are integrally connected by the connecting frame 246, so that the support strength of the step 23 can be further improved.

[0269] (Item E9) A cabin 1 described in any of items E1 to E8, in which a plurality of mounting portions 248 for attaching a mount portion 247 that supports the cabin 1 from below are provided on the underside of the reinforcement bracket 240 at a distance in the fore-and-aft direction.

[0270] According to the cabin 1 relating to item E9, multiple mounting portions 248 for attaching mounting portions 247 that support the cabin 1 from below are provided at a distance in the fore-and-aft direction on the underside of the reinforcing bracket 240, so that the mounting position of the mounting portions 247 can be changed as desired, and the mounting position of the cabin 1 relative to the aircraft body 3 can be adjusted forward and backward.

[0271] Although the present invention has been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0272] DESCRIPTION OF SYMBOLS 1 Cabin 6 Driver's seat 14 Rear pillar 17 Rear lower frame 17C Center portion of rear lower frame 17L Left end of rear lower frame 17R Right end of rear lower frame 32 Rear panel 200 Rear lower panel 201 Weather strip 201a Main lip 201b Sub-lip 202 Stepped member 202a Protruding end surface of stepped member 202b Lower surface of stepped member 202c Upper surface of stepped member 203 First sealing surface 204 Second sealing surface 206 Rear pillar cover 207 Fender cover 208 Support plate 210 Third sealing surface 211 Fourth sealing surface R1 First radius of curvature R2 Second radius of curvature

Claims

1. A cabin comprising a rear panel disposed behind the driver's seat, a rear lower frame disposed below the rear panel, and rear pillars disposed on the left and right sides of the rear panel, wherein the rear lower frame is composed of a stepped member protruding stepwise rearward and is curved such that the central portion is lowered downward with respect to both ends in the left-right direction.

2. A rear lower glass disposed below and behind the driver's seat, and a support plate for supporting an upper portion of the rear lower glass, wherein the support plate is disposed so as to close an opening in front of the stepped member. The cabin according to claim 1.

3. A weather strip disposed between the rear panel and the rear lower frame and between the rear panel and the rear pillar, wherein the stepped member has a first seal surface facing rearward and a second seal surface facing upward, and the weather strip is a double lip type including a main lip and a sub-lip, and is attached to the rear panel in a state where the main lip contacts the first seal surface and the sub-lip contacts the second seal surface between the rear panel and the rear lower frame. The cabin according to claim 1.

4. The rear pillar is provided with a rear pillar cover covering the rear surface of the rear pillar, the rear pillar cover has a third seal surface with which the sub-lip of the weather strip contacts, the rear surface of the rear pillar and the first seal surface of the rear lower frame are flush, and the second seal surface and the third seal surface are provided side by side on a curve having a single radius of curvature. The cabin according to claim 3.

5. A fender cover covering the rear portion of the fender is provided below the rear pillar, the fender cover has a fourth seal surface with which the sub-lip of the weather strip contacts, the rear surface of the fender cover and the first seal surface of the rear lower frame are flush, and the second seal surface and the fourth seal surface are provided side by side on a curve having a single radius of curvature. The cabin according to claim 4.

6. The rear lower frame has a protruding end face that protrudes rearward, a lower surface that is formed adjacent to the front portion of the protruding end face and faces downward, a second seal surface that is formed adjacent to the front portion of the protruding end face and faces upward, a first seal surface that is formed adjacent to the front portion of the second seal surface and faces rearward, and an upper surface that is formed adjacent to the front portion of the first seal surface and faces upward. The upper surface and the lower surface are inclined surfaces that incline downward as they extend rearward. The upper surface is throttled so that the inclination angle with respect to the horizontal direction is larger than that of the lower surface. The cabin according to claim 3.

7. The rear lower frame has a central portion that curves with a first radius of curvature and an end portion that curves with a second radius of curvature. The first radius of curvature and the second radius of curvature are different from each other. The cabin according to claim 1.

8. The first radius of curvature is formed to be larger than the second radius of curvature. The cabin according to claim 7.

Images