Cabin

Abstract

To provide a cabin that can provide improved bonding accuracy between members constituting a door frontage.SOLUTION: A cabin 1 includes: a door panel 27 disposed on a lateral side of a driver seat 6; a side lower beam 19 supporting a rear portion of the door panel 27 from below and extending from a rear upper end toward a front lower end in an arc shape; and a connection frame 20 supporting a front portion of the door panel 27 from below and extending forward from a lower end portion of the side lower beam 19 to the front. The lower end portion of the side lower beam 19 is bonded to an upper surface of a rear portion of the connection frame 20.SELECTED DRAWING: Figure 20

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a cabin in which long frames such as a front pillar, a rear pillar, a front upper frame, a front lower frame, a rear upper frame, a rear lower frame, a side upper beam, and a side lower beam are combined.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the cabin disclosed in Patent Document 1, a connecting frame that connects the side lower beam and the front pillar abuts and joins the front surface of the lower end portion of the side lower beam (side lower frame) from the front (see FIG. 2 of Patent Document 1).

[0005] However, in such a joining structure, there is a possibility that the joining accuracy with respect to the side lower beam may vary due to the influence of the dimensional tolerance of the length of the connecting frame.

[0006] The present invention has been made to solve such problems of the prior art, and an object thereof is to provide a cabin capable of improving the joining accuracy between members constituting the door width.

Means for Solving the Problems

[0007] The cab according to one aspect of the present invention includes a door panel disposed on the side of the driver's seat, a side rocker beam that supports the rear part of the door panel from below and extends in an arc shape from the upper end of the rear part toward the lower end of the front part, and a connecting frame that supports the front part of the door panel from below and extends forward from the lower end of the side rocker beam. The lower end of the side rocker beam is joined to the upper surface of the rear part of the connecting frame.

[0008] The front edge of the side rocker beam may have a curved portion that is curved in an arc shape and a straight portion that extends linearly in the tangential direction of the arc of the curved portion from the lower end of the curved portion toward the front lower side.

[0009] The rear edge of the side rocker beam may be curved in an arc shape behind the straight portion.

[0010] The distance between the front edge and the rear edge of the lower part of the side rocker beam may increase toward the lower end joined to the connecting frame.

[0011] A step mat is provided on the upper part of the connecting frame, and the straight portion may be provided below the upper surface of the step mat.

Advantages of the Invention

[0012] According to the above cab, the joining accuracy between the members constituting the door width can be improved.

Brief Description of the Drawings

[0013]

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DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, the cabin 1 of the present embodiment will be described with appropriate reference to the drawings.

[0015] FIG. 1 shows a side view of a tractor 2 having the cabin 1 of the present embodiment. In the present embodiment, the tractor 2 is exemplified as a work machine (vehicle) on which the cabin 1 of the present invention is mounted. However, as the work machine on which the cabin 1 of the present invention is mounted, a wheel loader, a backhoe, or the like may be used.

[0016] In this specification, the direction of arrow A1 in FIG. 1 (the forward direction of the tractor 2) is defined as the front, the direction of arrow A2 in FIG. 1 (the reverse direction of the tractor 2) is defined as the rear, and the direction of arrow A3 in FIG. 1 is defined as the front-rear direction for explanation. Therefore, the front side on the paper surface of FIG. 1 is the left side when explaining the tractor 2 or the cabin 1, and the back side on the paper surface of FIG. 1 is the right side when explaining the tractor 2 or the cabin 1. These directions are consistent with the directions seen from the operator OP who has boarded the tractor 2 (the driver's seat 6) (hereinafter, the human (driver) who boards the tractor 2 and drives or operates the tractor 2 is referred to as the operator OP). Also, the horizontal direction orthogonal to the front-rear direction A3 is the width direction (or left The tractor 2 and the cab 1 will be described with reference to the right direction). Further, the direction from the right part to the center part in the width direction of the tractor 2, or from the left part to the center part will be described as the inner side in the width direction. In other words, the inner side in the width direction is the direction in the width direction that approaches the center of the tractor 2.

[0017] As shown in FIG. 1, the tractor 2 has a travelable body (vehicle body) 3. The body 3 has a prime mover E1 and a transmission case 4.

[0018] The prime mover E1 generates a driving force for traveling the body 3, and a diesel engine is used in this embodiment. The prime mover E1 is located at the front part of the tractor 2 and is covered by a bonnet 10. The bonnet 10 is formed in a curved shape with its upper surface protruding slightly upward, and has a space inside that can accommodate the prime mover E1. In the tractor 2 of this embodiment, the prime mover E1 is stored in the space inside the bonnet 10.

[0019] Note that, instead of the diesel engine used in this embodiment, an electric motor may be used for the prime mover E1, or a hybrid type in which a diesel engine and an electric motor are combined may be used. The transmission case 4 is configured by directly connecting, for example, a flywheel housing that houses a flywheel, a clutch housing 107 (see FIG. 1) that houses a clutch that intermittently transmits the power of the prime mover E1 transmitted via the flywheel, and a transmission case that houses a transmission device that shifts the power transmitted via the clutch.

[0020] As shown in FIG. 1, the tractor 2 has a traveling device 5 that supports the body 3 so as to be travelable. The traveling device 5 of the tractor 2 illustrated in FIG. 1 is of a wheel type (four-wheel type) having a left front wheel 11L and a right front wheel 11R provided at the front part of the body 3, and a left rear wheel 12L and a right rear wheel 12R provided at the rear part of the body 3. In other words, the tractor 2 of this embodiment is provided with a traveling device 5 that travels on four wheels, namely, the left front wheel 11L, the right front wheel 11R, the left rear wheel 12L, and the right rear wheel 12R.

[0021] As shown in FIG. 1, the cabin 1 is a room where the operator OP enters to operate the aircraft 3, and in this embodiment, it is mounted at the rear of the aircraft 3. A driver's seat 6 on which the operator OP sits is provided at the rear of the interior of the cabin 1 (referred to as the cabin interior). In front of the driver's seat 6, for example, a steering wheel 7 for steering the left front wheel 11L and the right front wheel 11R is provided.

[0022] As shown in FIGS. 1 and 2, the cabin 1 has a cabin frame 8 formed by three-dimensionally and lattice-like combining long frame members. That is, the cabin frame 8 constitutes the framework (outer skeleton) of the cabin 1 and has a plurality of long frame members. Further, panel members such as a front panel 31 and a door (door panel 27) are arranged between the frame members combined three-dimensionally and lattice-like in the cabin frame 8. In addition, a roof 9 is provided on the upper part of the cabin frame 8. The cabin frame 8 of this embodiment is a four-pillar type without a center pillar (quarter pillar) as shown in FIG. 2.

[0023] As shown in FIGS. 2 to 6 (particularly in detail in FIG. 2), the cabin frame 8 has a plurality of long frame members. In the case of this embodiment, the frame members constituting the cabin frame 8 are eleven in number, namely, 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. Hereinafter, each frame member constituting the cabin frame 8 will be described in detail.

[0024] As shown in detail in FIGS. 2 to 5, a left front pillar 13L and a right front pillar 13R are provided at the front part of the cabin frame 8 (in front of the driver's seat 6). The left front pillar 13L and the right front pillar 13R are arranged side by side with a space therebetween in the width direction, and are both arranged so as to extend along the vertical direction. The left front pillar 13L is provided at the left front corner of the cabin 1. The right front pillar 13R is provided at the right front corner of the cabin 1. A front beam 15 is spanned between the upper part of the left front pillar 13L and the upper part of the right front pillar 13R. That is, the upper part of the left front pillar 13L and the upper part of the right front pillar 13R are connected to each other left and right by the front beam 15.

[0025] Hereinafter, the left front pillar 13L and the right front pillar 13R may be collectively referred to as the front pillar 13. As shown in FIGS. 2, 3, 5, and 6, a left rear pillar 14L and a right rear pillar 14R are provided at the rear part 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 space therebetween in the width direction, and are both arranged so as to extend along the vertical direction. The left rear pillar 14L is provided at the left rear corner of the cabin 1. The right rear pillar 14R is provided at the right rear corner of the cabin 1. A rear beam 16 is spanned between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. That is, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected to each other left and right by the rear beam 16. Also, a rear lower frame 17 is spanned between the lower part of the left rear pillar 14L and the lower part of the right rear pillar 14R. That is, the lower part of the left rear pillar 14L and the lower part of the right rear pillar 14R are connected to each other left and right by the rear lower frame 17.

[0026] Hereinafter, the left rear pillar 14L and the right rear pillar 14R may be collectively referred to as the rear pillar 14.

[0027] As shown in FIGS. 2, 3, and 5, on the upper part of the cabin frame 8, a left side beam 18L and a right side beam 18R are provided. The left side beam 18L and the right side beam 18R are arranged side by side with a space therebetween in the width direction, and both are arranged so as to extend along the front-rear direction. The left side beam 18L is curved such that the middle part in the front-rear direction bulges upward compared to the front end and the rear end. Also, the right side beam 18R is curved such that the middle part in the front-rear direction bulges upward compared to the front end and the rear end.

[0028] The left side beam 18L is spanned between the upper part of the left front pillar 13L and the upper part of the left rear pillar 14L. That is, the upper part of the left front pillar 13L and the upper part of the left rear pillar 14L are connected front and rear by the left side beam 18L.

[0029] The right side beam 18R is spanned between the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R. That is, the upper part of the right front pillar 13R and the upper part of the right rear pillar 14R are connected front and rear by the right side beam 18R.

[0030] Incidentally, hereinafter, the left side beam 18L and the right side beam 18R may be collectively referred to as the side beam 18.

[0031] As shown in FIGS. 2 and 3, on the lower part of the cabin frame 8, a left side lower beam 19L and a right side lower beam 19R are provided. The left side lower beam 19L and the right side lower beam 19R are arranged side by side with a space therebetween in the width direction.

[0032] The left side lower beam 19L is formed so as to draw an arc from the lower part of the left front pillar 13L toward the front lower side. That is, the left side lower beam 19L extends so as to shift downward as it goes forward from the lower part of the left rear pillar 14L. And the lower end portion of the left side lower beam 19L that extends so as to shift downward is connected in the front-rear direction to the lower end portion of the left front pillar 13L via the left connecting frame 20L.

[0033] The right side lower beam 19R is formed so as to draw an arc from the lower part of the right front pillar 13R toward the front lower side. That is, the right side lower beam 19R extends so as to shift downward as it goes forward from the lower part of the right rear pillar 14R. And the lower end portion of the right side lower beam 19R that extends so as to shift downward is connected in the front-rear direction to the lower end portion of the right front pillar 13R via the right connecting frame 20R.

[0034] Hereinafter, the left side lower beam 19L and the right side lower beam 19R are collectively referred to as the side lower beam 19.

[0035] As shown in FIG. 2, a fender 21L (left rear wheel fender) that covers the left rear wheel 12L is fixed to the lower surface of the left side lower beam 19L and the lower end portion of the left rear pillar 14L. Also, a fender 21R (right rear wheel fender) that covers the right rear wheel 12R is fixed to the lower surface of the right side lower beam 19R and the lower end portion of the right rear pillar 14R.

[0036] Also, as shown in FIGS. 2, 4, 5, and 6, a front beam 15 is provided at the front part and a rear beam 16 is provided at the rear part on the upper part of the cabin frame 8.

[0037] The front beam 15 and the rear beam 16 are arranged side by side at intervals in the front-rear direction, and are both formed as long frame members extending along the left-right direction. The middle part of the front beam 15 in the left-right direction is curved so as to bulge upward compared to the left end and the right end. Also, the rear beam 16 extends linearly along the left-right direction with almost no change in height in the up-down direction.

[0038] The front beam 15 is bridged between the upper part of the left front pillar 13L and the upper part of the right front pillar 13R. That is, the upper part of the left front pillar 13L and the upper part of the right front pillar 13R are connected to the left and right by the front beam 15.

[0039] The rear beam 16 is bridged between the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R. That is, the upper part of the left rear pillar 14L and the upper part of the right rear pillar 14R are connected to the left and right by the rear beam 16.

[0040] As described above, the cabin frame 8 of the present embodiment is formed by combining frame members such as the above-described left front pillar 13L, right front pillar 13R, left rear pillar 14L, right rear pillar 14R, front beam 15, rear beam 16, rear lower frame 17, left side beam 18L, right side beam 18R, left side lower beam 19L, and right side lower beam 19R.

[0041] As shown in FIGS. 2 and 5, a floor seat 22 is provided between the fender 21L (left rear wheel fender) and the fender 21R (right rear wheel fender). The floor seat 22 is arranged horizontally below the driver's seat 6, and the driver's seat 6 is attached to this floor seat 22. The rear part of the floor seat 22 extends obliquely upward and is located on the back side of the driver's seat 6. From the front lower end of the floor seat 22 forward, a step 23 that constitutes a floor is provided at a position lower than the floor seat 22. Ste The step 23 is a plate (step plate) that constitutes the floor of the cabin 1. The upper surface of the step 23 is adapted to support the feet of the operator OP seated in the driver's seat 6.

[0042] As shown in FIGS. 1, 3, 4, and 6, the roof 9 is disposed above the cabin frame 8 to prevent rain, wind, and direct sunlight from entering the cabin 1. The roof 9 includes an inner roof 24 that constitutes the ceiling portion of the interior of the cabin 1 and an outer roof 25 that constitutes the upper wall of the ceiling portion. A hollow space is formed between the inner roof 24 and the outer roof 25, creating a space where the air conditioner 26 (air conditioning device) for air conditioning the cabin interior can be arranged.

[0043] As shown in FIGS. 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 / gangway 28L on the left side surface of the cabin 1 and a right boarding / gangway 28R on the right side surface of the cabin 1. A left door (left door panel 27L) (see FIGS. 1 and 5) that closes the left boarding / gangway 28L is provided at the left boarding / gangway 28L. A right door (right door panel 27R) (see FIGS. 3 and 5) that closes the right boarding / gangway 28R is provided at the right boarding / gangway 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.

[0044] The left boarding / gangway 28L is an opening surrounded by the left front pillar 13L, the left side beam 18L, the left rear pillar 14L, the left side rocker frame 19L, and the left connecting frame 20L, and opens to the left. The left boarding / gangway 28L can be closed by the left door 27L. The left door 27L is supported by the left rear pillar 14L via two door hinges at the upper and lower positions. The two door hinges at the upper and lower positions are the first door hinge 29L provided at the upper part of the left rear pillar 14L and the second door hinge 30L provided at the lower part of the first door hinge 29L. That is, the left door 27L can open and close the left boarding / gangway 28L by swinging the front end in the left-right direction with respect to the rear end provided with the first door hinge 29L and the second door hinge 30L.

[0045] 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 floor frame 19R, and the right connecting frame 20R, and opens towards the right. The right entrance / exit opening 28R can be closed by the right door 27R. The right door 27R is supported via two door hinges at upper and lower positions with respect to the right rear pillar 14R. The two door hinges at upper and lower positions are the first door hinge 29R provided at the upper part of the right rear pillar 14R and the second door hinge 30R provided at the lower part of the first door hinge 29R. That is, the right door 27R can open and close the right entrance / exit opening 28R by swinging the front end in the left-right direction with respect to the rear end provided with the first door hinge 29R and the second door hinge 30R.

[0046] The above-described left door 27L and right door 27R are formed by panels having light transmissibility such as tempered glass and acrylic glass, and good visibility from the interior of the cabin 1 to the outside of the vehicle can be ensured.

[0047] As shown in FIG. 5, the cabin 1 of the present embodiment includes a front panel 31 at the front part of the cabin frame 8 and a rear panel 32 at the rear part of the cabin frame 8.

[0048] The front panel 31 is disposed between the left front pillar 13L and the right front pillar 13R which are arranged at a distance from each other left and right, and is supported from the left and right by the left front pillar 13L and the right front pillar 13R. Further, the upper edge of the front panel 31 is fixed to the front beam 15 disposed above the front panel 31. The front panel 31 is formed by a panel having light transmissibility such as tempered glass and acrylic glass, and good visibility from the interior of the cabin 1 to the outside of the vehicle (front) can be ensured.

[0049] The front panel 31 of the present embodiment is formed in a curved surface shape that bulges forward. That is, when the front panel 31 is cut along the horizontal direction, the horizontal cross-section of the front panel 31 has an arc shape in which the central portion in the left-right direction protrudes forward compared to the left end and the right end. Further, when the front panel 31 is cut along the vertical direction, the vertical cross-section of the front panel 31 has an arc shape in which the central portion in the up-down direction protrudes forward compared to the upper end and the lower end. By forming the front panel 31 into a curved surface that bulges forward, it is possible to improve the visibility from the interior of the cabin 1 to the front outside the vehicle, particularly downward.

[0050] The cabin 1 of the present invention has the following characteristics.

[0051] As shown in FIGS. 2, 5, and 7, the cabin 1 of the present 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. Both the rear panel 32 and the rear lower panel 200 are formed in a plate shape that curves outward and is made of a material having light transmissibility 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.

[0052] As shown in FIG. 7, a weather strip 201 is provided around (the periphery of) the rear panel 32. As shown in FIG. 8, the weather strip 201 is of a double lip type including a main lip 201a and a sub lip 201b. The weather strip 201 is provided over the entire circumference at the outer edge of the rear panel 32. That is, the weather strip 201 is also arranged between the rear panel 32 and the rear lower frame 17 provided below the rear panel 32. Further, the weather strip 201 is also arranged between the rear panel 32 and the rear pillars 14 provided on the left and right sides of the rear panel 32.

[0053] On the left and right sides of the rear panel 32, rear pillars 14 are arranged. The rear pillar 14 is composed of a left rear pillar 14L arranged on the left side of the rear panel 32 and a right rear pillar 14R arranged on the right side of the rear panel 32. The lower part of the left rear pillar 14L is joined to the left end of the rear lower frame 17. The lower part of the right rear pillar 14R is joined to the right end of the rear lower frame 17.

[0054] As shown in FIG. 8, the rear lower frame 17 is composed of a stepped member 202. The stepped member 202 protrudes in a stepped manner rearward. The stepped member 202 is open at the front.

[0055] As shown in FIG. 8, in the stepped member 202 of the present embodiment, among the surfaces of the rear part formed in a stepped shape, the surface facing rearward is the first seal surface 203, and the surface facing upward is the second seal surface 204. The main lip 201a of the weather strip 201 contacts the first seal surface 203 of the stepped member 202, and the sub-lip 201b of the weather strip 201 contacts the second seal surface 204.

[0056] Specifically, the stepped member 202 has a protruding end surface 202a protruding rearward, a lower surface 202b formed adjacent to the front of the protruding end surface 202a and facing downward, a second seal surface 204 formed adjacent to the front of the protruding end surface 202a and facing upward, and the second seal surface 204 a first seal surface 203 formed adjacent to the front of the second seal surface 204 and facing rearward, and an upper surface 202c formed adjacent to the front of the first seal surface 203 and facing upward.

[0057] The main lip 201a of the weatherstrip 201 is brought into contact with the first seal surface 203 of the stepped member 202, and the sub-lip 201b of the weatherstrip 201 is brought into contact with the second seal surface 204 of the stepped member 202 to perform sealing, whereby the sealing performance between the stepped member 202 and the rear panel 32 can be improved. Further, even if rainwater tries to penetrate inside the rear panel 32 by getting over the sub-lip 201b of the weatherstrip 201, it is blocked by the main lip 201a. Further, since the rear lower frame 17 is curved downward as described later, the rainwater that has got over the sub-lip 201b flows down along this curvature through the space formed between the main lip 201a and the sub-lip 201b. Therefore, it is possible to quickly flow down the infiltrated rainwater downward.

[0058] As shown in FIG. 10, the upper surface 202c of the stepped member 202 is an inclined surface that slopes downward as it goes rearward. In this way, by making the upper surface 202c of the rear lower frame 17 that supports the lower part of the rear panel 32 an inclined surface that slopes rearward, it is possible to secure the view from the driver (operator OP) through the rear panel 32 to the rear, particularly the view to the lower rear. The lower surface 202b of the stepped member 202 is also an inclined surface that slopes downward as it goes rearward. 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.

[0059] The stepped member 202 having the above-described shape (a stepped shape with an open front) is formed by pressing a metal plate. Specifically, the stepped member 202 is formed by pressing a metal plate (specifically, drawing). That is, the rear lower frame 17 composed of the stepped member 202 is formed by pressing a metal plate (drawing). Therefore, the rear lower frame 17 is easy to adjust its shape during processing. Specifically, as described later, the rear lower frame 17 is formed in a curved shape, but it is easy to adjust the magnitude of the curvature during processing.

[0060] In the case of a conventional cabin, the rear underframe is composed of metal square pipes. Therefore, when the rear underframe is formed into a curved shape, the rigid square pipes must be bent, and it is difficult to adjust the amount of curvature. In particular, it is difficult to change the amount of curvature (radius of curvature) depending on the part of the rear underframe.

[0061] On the other hand, since the rear underframe 17 of the cabin 1 of the present invention is formed from a stepped member 202 formed by pressing (drawing), it is easy to adjust the amount of curvature during processing. Therefore, it is also easy to change the amount of curvature (radius of curvature) depending on the part of the rear underframe 17.

[0062] As shown in FIG. 11, the rear underframe 17 is curved such that the central portion 17C descends downward with respect to both ends in the left-right direction (left end 17L and right end 17R). The rear underframe 17 is not only curved so as to simply descend downward, but is also curved such that the radius of curvature changes according to the position in the left-right direction. That is, the radius of curvature of the downward curvature of the rear underframe 17 changes according to the position in the left-right direction.

[0063] Specifically, the rear underframe 17 has a central portion 17C that curves with a first radius of curvature R1 and end portions (left end 17L and right end 17R) that curve with a second radius of curvature R2. In FIG. 11, the range of the central portion 17C that curves with the first radius of curvature R1 is indicated by R1, and the range of the end portions that curve with the second radius of curvature R2 is indicated by R2. The central portion 17C, the left end 17L, and the right end 17R are each provided over a predetermined length range in the left-right direction. The length of the central portion 17C in the left-right direction is larger than the lengths of the left end 17L and the right end 17R in the left-right direction. 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 formed to be larger than the second radius of curvature R2 (R1>R2).

[0064] In this way, by changing the radius of curvature of the curvature of the rear lower frame 17 toward the lower side according to the position in the left - right direction, and in particular by forming the first radius of curvature R1 larger than the second radius of curvature R2, the angle of the arrangement of the rear lower frame 17 with respect to the rear pillar 14 can be made gentle (a large angle at the center side of the rear panel 32). As a result, it is possible to avoid large deformation of the weather strip 201 provided across the rear lower frame 17 and the rear pillar 14, and it is possible to prevent a decrease in the sealing performance near the boundary between the rear lower frame 17 and the rear pillar 14.

[0065] As shown in the plan view of FIG. 12, the rear lower frame 17 is curved such that the central portion 17C is directed rearward with respect to both ends in the left - right direction (left end 17L, right end 17R). The rear lower frame 17 is not only curved so as to be directed rearward, but also curved such that the radius of curvature changes according to the position in the left - right direction. That is, the radius of curvature of the curvature of the rear lower frame 17 toward the rear changes according to the position in the left - right direction.

[0066] Specifically, the rear lower frame 17 has a central portion 17C that curves with a first radius of curvature R3 and end portions (left end 17L, right end 17R) that curve with a second radius of curvature R4. The central portion 17C, the left end 17L, and the right end 17R are each provided over a predetermined length range in the left - right direction. The length of the central portion 17C in the left - right direction is larger than the lengths of the left end 17L and the right end 17R in the left - right direction. 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 formed larger than the second radius of curvature R4 (R3>R4).

[0067] In this way, by changing the radius of curvature of the curvature of the rear lower frame 17 toward the rear according to the position in the left - right direction, it becomes possible to correspond to cabins having different sizes in the width direction. Specifically, by changing the first radius of curvature R3 of the central portion 17C, it becomes possible to adjust the front - rear position of the driver's seat corresponding to cabins having different sizes in the width direction.

[0068] 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 decreased. When the first radius of curvature R3 of the central portion 17C is decreased, the central portion 17C protrudes significantly rearward compared to the ends (left end 17L, right end 17R). Then, since the space in the front - rear direction inside the cabin expands, the position of the driver's seat can be shifted rearward. As a result, for a large - sized cabin 1 with a large width, it becomes possible to expand the internal space of the cabin not only in the left - right direction (width direction) but also in the front - rear direction, and optimize the front - rear position of the driver's seat.

[0069] Also, the second radius of curvature R4 of the ends (left end 17L, right end 17R) of the rear lower frame 17 can be changed corresponding to the cabin 1 with different widths. 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 so that the ends of the rear lower frame 17 and the rear pillar 14 are smoothly connected. As a result, it becomes possible to make the rear pillar cover 206 and the fender cover 207 common for cabins 1 with different widths.

[0070] As described above, the radius of curvature of the downward - curving and the radius of curvature of the rear - curving of the rear lower frame 17 change according to the position in the left - right direction. Since the rear lower frame 17 is composed of the stepped member 202, while ensuring sufficient strength (rigidity) and sealing performance for the rear lower frame 17, it is possible to easily realize a shape in which such a radius of curvature changes.

[0071] As shown in FIG. 8, the opening in front of the stepped member 202 is closed by the support plate 208. The support plate 208 is inclined so as to shift rearward as it goes 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. Further, the support plate 208 supports the upper part of the rear lower panel 200. The lower front surface 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 opening in front of the stepped member 202.

[0072] The upper part of the support plate 208 is joined from below to the upper plate portion 202d having the upper surface 202c of the stepped member 202. Further, the lower part of the support plate 208 is joined to the front end portion of the lower plate portion 202e having the lower surface 202b of the stepped member 202. Thereby, the support plate 208 closes the opening in front of the stepped member 202.

[0073] In this way, after the rear lower frame 17 is constituted by the stepped member 202, by joining so as to close the opening in front of the stepped member 202 with the support plate 208, it becomes possible to increase the rigidity (strength) of the rear lower frame 17. Further, by also using the support plate 208, which is a member that supports the upper part of the rear lower panel 200, as a member for increasing the rigidity of the rear lower frame 17, it is possible to realize the support of the rear lower panel 200 and the improvement of the rigidity of the rear lower frame 17 with a small number of parts.

[0074] As shown in FIG. 7, rear pillars 14 are arranged on the left and right sides of the rear panel 32. The rear pillar 14 is provided with a left rear pillar 14L arranged on the left side of the rear panel 32 and a right rear pillar 14R arranged on the right side of the rear panel 32. The rear pillar 14 is provided with a rear pillar cover 206 that covers the rear surface of the rear pillar 14.

[0075] As described above, the weather strip 201 has a main lip 201a and a sub-lip 201b, and the main lip 201a and the sub-lip 201b face the lip tips in a direction intersecting each other (see Fig. 8). Specifically, the main lip 201a extends forward and backward, and the sub-lip 201b extends downward.

[0076] In the case of the rear lower frame 17 shown in Fig. 8, the main lip 201a contacts the first seal surface 203 facing the rear, and the sub-lip 201b contacts the second seal surface 204 facing upward. The weather strip 201 contacts not only the rear lower frame 17 but also the rear pillar 14.

[0077] As shown in Fig. 13, the rear surface 14a of the rear pillar 14 and the first seal surface 203 of the rear lower frame 17 are flush. Therefore, the main lip 201a of the weather strip 201 provided so as to straddle the rear pillar 14 and the rear lower frame 17 contacts the first seal surface 203 of the rear lower frame 17 and the rear surface 14a of the rear pillar 14. At this time, since the rear surface 14a of the rear pillar 14 and the first seal surface 203 of the rear lower frame 17 are flush as described above, the main lip 201a contacts continuously from the first seal surface 203 of the rear lower frame 17 to the rear surface 14a of the rear pillar 14, and a good sealing state can be obtained even at the boundary between the rear pillar 14 and the rear lower frame 17.

[0078] However, for the sub-lip 201b of the weather strip 201, there is no portion that can contact the rear pillar 14. Therefore, in the cabin 1 of the present embodiment, the rear pillar cover 20 6 is provided with a third seal surface 210 that the sub-lip 201b of the weather strip 201 contacts. The third seal surface 210 is curved so as to shift inward in the width direction as it goes downward. Specifically, the third seal surface 210 is a surface curved so as to shift from the surface facing inward in the width direction to the surface facing upward.

[0079] Note that depending on the model, the rear pillar cover 206 and the rear lower frame 17 may be arranged at a distance from each other in the left - right direction and may not be adjacent. For example, in the cabin 1 of the present embodiment, as shown in FIG. 13, a fender cover 207 that covers the rear part of the fender 21 is arranged 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 weather strip 201 contacts is provided on the upper part of the fender cover 207.

[0080] The above - described second seal surface 204 and third seal surface 210 are provided side by side on a curve having a single radius of curvature. Also, the second seal surface 204 and the fourth seal surface 211 are provided side by side on a curve having a single radius of curvature. By providing 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 in this way, the second seal surface 204, the fourth seal surface 211, and the third seal surface 210 are arranged on one curve. Thereby, excessive deformation of the weather strip 201 that contacts and is arranged on the second seal surface 204, the fourth seal surface 211, and the third seal surface 210 can be suppressed, and a decrease in sealing performance can be prevented. Also, among the seals of the weather strip, not only the main lip but also the sub - lip can be arranged side by side on a curve having a single radius of curvature, so that excessive deformation of the seal can be suppressed and a decrease in sealing performance can be prevented.

[0081] When the second seal surface 204 and the third seal surface 210 are provided side by side on a curve having a single radius of curvature, the radius of curvature of the curve can be, for example, 80 - 120 mm (specifically, about 100 mm). By setting the radius of curvature in this way, excessive deformation of the weather strip 201 can be suppressed and a decrease in sealing performance can be prevented.

[0082] Also, in order to arrange the second sealing surface 204 and the third sealing surface 210 side by side on such a curve, it is necessary to make the angle (inner angle) of the joint portion between the rear pillar 14 and the rear lower frame 17 a gentler (larger) angle than an angle close to a right angle. For this purpose, it is necessary to appropriately adjust the radii of curvature of the left and right end portions of the second sealing surface 204. Such adjustment can be easily performed because, as described above, the curved shape of the rear lower frame 17 can be easily adjusted.

[0083] FIG. 14 is a view showing the rear part of the driver's seat 6 as seen from the front. As shown in FIG. 14, a pair of side frames 205L and 205R are arranged on the left and right sides of a rear lower panel 200 provided below the rear of the driver's seat 6. Hereinafter, the side frames 205L and 205R are collectively referred to as the side frame 205.

[0084] 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 so as to incline leftward toward the upper rear. The upper end of the left side frame 205L is joined to the lower left end of the rear lower frame 17.

[0085] 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 so as to incline rightward toward the upper rear. The upper end of the right side frame 205R is joined to the lower right end of the rear lower frame 17.

[0086] That is, the left side frame 205L extends upward so as to incline leftward, and the right side frame 205R extends upward so as to incline rightward. That is, the pair of side frames 205L and 205R are arranged so as to flare out toward the upper rear.

[0087] The right part of the left side frame 205L supports the left end of the rear lower panel 200. The left end of the rear lower panel 200 is supported by the right part of the left side frame 205L over the entire vertical range from the lower end to the upper end, except for the upper part supported by the support plate 208. Also, the left part of the right side frame 205R supports the right end of the rear lower panel 200. The right end of the rear lower panel 200 is supported by the left part of the right side frame 205R over the entire vertical range from the lower end to the upper end, except for the upper part supported by the support plate 208.

[0088] By thus supporting the left and right ends of the rear lower panel 200 over the entire vertical range by the pair of side frames 205L and 205R, the left and right ends of the rear lower panel 200 flare out as they go toward the upper rear. As a result, the rear lower panel 200 can widen the field of view up to the upper left and upper right corners (both upper corners), secure the field of view toward the rear through both upper corners of the rear lower panel 200, and widen the field of view to the rear.

[0089] Note that if the pair of side frames 205L and 205R are arranged to flare out as they go toward the upper rear in order to widen the field of view to the rear, the strength of the rear frame structure will be insufficient, and thus reinforcement of the rear frame structure will be necessary. Therefore, in the cabin 1 of the present embodiment, reinforcement of the rear frame structure as described in the following (1) to (4) is performed.

[0090] (1) The pair of side frames 205L and 205R are formed in an inverted taper shape where the upper end is wider in the left - right direction than the lower end. The pair of side frames 205L and 205R described above are formed of frame members whose width widens in an inverted taper shape such that the upper end is wider in the left - right direction than the lower end connected to the base frame 213. By using such a pair of side frames 205L and 205R whose width widens in an inverted taper shape, the joint area with the rear lower panel 200 can be increased, and the strength of the rear frame structure can be enhanced.

[0091] (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 in the lateral direction. As shown in FIG. 14, the upper end of the side frame 205 is joined to the left and right ends of the rear lower frame 17 in the lateral direction. 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 to the right end 17R of the rear lower frame 17 from below. A right rear wheel fender 21R is arranged on the left part of the right side frame 205, and the right rear pillar 14R is joined to the further left part of the right rear wheel fender 21R. That is, 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 description 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.

[0092] In this way, since 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 in the lateral direction, the joining positions of the lower end of the rear pillar 14 and the upper end of the side frame 205 are close or adjacent to each other in the lateral direction of the rear lower frame 17. As a result, compared with the case where the joining positions of the lower end of the rear pillar 14 and the upper end of the side frame 205 are separated from each other in the lateral direction, the rear lower frame 17 is less likely to bend, so that the strength of the rear frame structure can be increased.

[0093] Note that 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. That is, the most preferable joint structure is such that the upper end of the side frame 205 is adjacent in the left - right direction to the lower part of the rear pillar 14. In this way, the strength of the frame structure formed by joining the side frame 205, the rear lower frame 17, and the rear pillar 14 can be maximally improved.

[0094] (3) As shown in FIG. 15, a support plate 208 (see FIG. 8) that closes the opening in front of the stepped member 202 is joined to both the side frame 205 and the rear pillar 14.

[0095] The support plate 208 is joined to the rear pillar 14 along the first joint line 214 and to the side frame 205 along the second joint line 215.

[0096] In this way, the support plate 208 is arranged to close the opening in front of the stepped member 202, and since the support plate 208 is joined to both the side frame 205 and the rear pillar 14, the strength of the rear lower frame 17 can be increased.

[0097] (4) On the outer side in the left - right direction of the side frame 205, fenders 21 (left rear - wheel fender 21L, right rear - wheel fender 21R) that curve rearward as they go upward are arranged. The rear end of the fender 21 is joined to the lower part of the rear pillar 14, and the stepped member 202 is joined to the rear end of the fender 21.

[0098] As shown in FIG. 15, the right rear - wheel fender 21R is arranged to the left of the right - hand side frame 205R. A third joint 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 joint line 216.

[0099] 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 welding piece 255.

[0100] By joining the left rear wheel fender 21L to the stepped member 202 in this way, the four members of the rear pillar 14, the side frame 205, the rear lower frame 17, and the fender 21 can be joined with high strength.

[0101] Also, the upper surface of the rear part of the fender 21 described above is formed in an inclined shape that slopes upward as it goes outward in the left - right direction. That is, a space is formed above the upper part of the upper surface of the fender 21 to secure a rearward view above the rear part of the fender 21, and it becomes easy to secure a rearward view through this space.

[0102] In a work machine such as the 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. Due to the increased pressure inside the cabin 1, problems such as the door 27 that should be closed opening contrary to the operator's intention may occur. To avoid such indoor air pressure fluctuations, the cabin 1 of the present invention is provided with an exhaust system 220 that discharges the air inside the cabin 1 to the outside when the pressure (air pressure) inside the cabin 1 exceeds a predetermined pressure. of the pressure (air pressure) exceeds a predetermined pressure.

[0103] As shown in FIG. 14, the exhaust system 220 includes an airframe wall disposed around the driver's seat 6, an air vent hole 222 opened in the airframe wall, and a water - stop cover 223 (see FIG. 7) attached to the airframe wall. This airframe wall means the front wall, the left and right side walls, and the rear wall part disposed around the driver's seat 6. Which of the front wall, the left and right side walls, and the rear wall part to provide the exhaust system 220 varies depending on the model. However, when the airframe 3 has a front wall, left and right side walls, and a rear wall part, etc., an air vent hole 222 is preferably formed in any of the walls. Note that the cabin 1 of the present embodiment is exemplified as having a rear wall part 221 disposed behind the driver's seat 6 as the airframe wall, and an air vent hole 222 is provided in the rear wall part 221.

[0104] That is, the exhaust system 220 of the present embodiment has a rear wall portion 221 disposed behind the driver's seat 6, and an air vent hole 222 is provided in the rear wall portion 221.

[0105] As shown in FIG. 14, the exhaust system 220 of the present embodiment includes an air vent hole 222 provided in the rear wall portion 221 and a water stop cover 223 (see FIG. 7) provided in the rear wall portion 221. A closing plate 224 for closing the air vent hole 222 is provided in the rear wall portion 221.

[0106] 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.

[0107] As shown in FIGS. 2 and 14, the rear wall portion 221 is an airframe wall disposed behind the driver's seat 6. The rear wall portion 221 is formed in an inclined shape that shifts rearward as it goes downward. A recess 225 that is recessed rearward and downward is formed in the upper portion of the rear wall portion 221, and the air vent hole 222 is formed in the recess 225. By providing the air vent hole 222 in the rear wall portion 221 at the rear, which is the least likely to interfere with other devices among the front, rear, left, and right of the driver's seat 6, it is possible to suppress large indoor pressure fluctuations (rapid pressure increase) when the door is closed without degrading the operability and habitability inside the cabin 1.

[0108] As shown in FIG. 14, the air vent hole 222 is a hole having a horizontally long rectangular opening in front view, and a plurality (four in the case of the present embodiment) are formed side by side in the left - right direction in the rear wall portion 221.

[0109] As shown in FIG. 18, a recess 225 that is recessed in a trapezoidal shape in a side view is formed in the rear wall portion 221. An inclined wall portion 226 that is inclined so as to shift upward as it goes forward is formed above the recess 225, and an air vent hole 222 is formed in the inclined wall portion 226. Further, the recess 225 is formed over a range from the left end to the right portion of the rear wall portion 221 (a range of approximately 3 / 4 of the entire width in the left - right direction), so that the air in the cabin 1 can be released over a wide range.

[0110] By providing such an air vent hole 222 and extracting air from the interior of the cabin 1, it is possible to prevent the occurrence of problems such as large pressure fluctuations (rapid pressure increase) inside the cabin when the door is closed and the door being pushed back due to large pressure fluctuations.

[0111] The closing plate 224 is a plate that can close the opening of the air vent hole 222. The closing plate 224 is formed of, for example, rubber, synthetic resin, or the like. In the case of this embodiment, the closing plate 224 is formed of rubber. The upper end of the closing plate 224 is fixed to the rear wall portion 221 above the air vent hole 222. Specifically, the upper end of the closing plate 224 is fixed to the inclined wall portion 226 slightly above the opening of the air vent hole 222 by means such as riveting or adhesion, and covers the air vent hole 222 from the upper surface side of the inclined wall portion 226. The portion of the closing plate 224 below the fixed upper end is capable of swinging (deforming) upward. When the pressure in the cabin 1 exceeds a predetermined pressure, it swings upward with the upper end portion as a fulcrum.

[0112] When the pressure inside the cabin 1 is less than the predetermined pressure, the closing plate 224 does not swing, so it maintains the state of covering the air vent hole 222 from the upper surface side of the inclined wall portion 226 and closes the air vent hole 222. That is, when the pressure inside the cabin 1 is less than the 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 upward and rearward due to the action of the pressure exceeds the force that the closing plate 224 tries to close the air vent hole 222 by its own weight, and the closing plate 224 swings upward and rearward to open the air vent hole 222.

[0113] The pressure (predetermined pressure) inside the cabin 1 when the closing plate 224 swings is determined according to the weight of the closing plate 224. If the weight of the closing plate 224 is large, a high pressure is required as the pressure for swinging the closing plate 224. If the weight of the closing plate 224 is small, the pressure for swinging the closing plate 224 may be low. Therefore, if a thick plate is used as the closing plate 224 or a weight is added to the upper surface of the closing plate 224, etc., the pressure for swinging the closing plate 224 can be set high.

[0114] For example, when it is stipulated by laws and regulations, etc., to set the air pressure inside the cabin 1 higher, by using the closing plate 224 formed of a thick plate or the closing plate 224 with a weight added, it becomes possible to set the air pressure inside the cabin 1 higher so that exhaust is performed by the swinging of the closing plate 224.

[0115] Also, by appropriately setting the weight of the closing plate 224, for example, when the air conditioner is operated to introduce outside air, the closing plate 224 does not open, and the cold air or warm air inside the cabin 1 is not wasted and discharged to the outside. However, when the door is closed, it becomes possible to release the air inside the cabin 1 to the outside and suppress the fluctuation (sharp rise) of the air pressure inside the cabin 1.

[0116] In addition, a plurality of closing plates 224 are provided corresponding to the plurality of air vent holes 222. Specifically, a plurality of closing plates 224 are provided to individually close the plurality of air vent holes 222. Therefore, it is also possible to make the weight of some of the closing plates 224 different from the weight of the remaining closing plates 224 among the plurality of air vent holes 222. Thereby, for example, when the pressure fluctuation in the cabin 1 is small, some (a small number) of the air vent holes 222 are opened, and when the pressure fluctuation in the cabin 1 becomes 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, and the air in the cabin 1 can be exhausted individually for each of the plurality of air vent holes 222.

[0117] In the case of this embodiment, whether the closing plate 224 swings (opens) is determined by the magnitude of the weight of the closing plate 224 itself. However, the pressure in the cabin 1 may be measured using a pressure gauge or the like, and whether the measured air pressure has reached a predetermined pressure may be determined by a control unit or the like, and a motor or the like may be driven according to the determination result to open the closing plate 224.

[0118] In addition, the closing plate 224 has a rib portion 233 extending along the left - right direction at the rear end. If the rib portion 233 is formed on the closing plate 224, warping and deformation of the closing plate 224 are suppressed by the rib portion 233. Therefore, it is possible to avoid the problem that the air vent hole 222 cannot be surely closed due to the warped or deformed closing plate 224.

[0119] The water - stop cover 223 is arranged to cover the air vent hole 222. The water - stop cover 2 23 forms a space with the lower part open between it and the rear wall portion 221 (aircraft wall).

[0120] As shown in Fig. 17, the water stop cover 223 has a back plate portion 223a, left and right side plate portions 223b, and an upper plate portion 223c. The back plate portion 223a is disposed behind the rear wall portion 221 (aircraft body wall) with a space therebetween. 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 and the left and right side plate portions 223b.

[0121] The space formed between the water stop cover 223 and the rear wall portion 221 is covered by the upper plate portion 223c above, by the left and right side plate portions 223b on the left and right sides, by the back plate portion 223a at the rear, and only the lower part is open. The open part (lower end portion) below the water stop cover 223 is provided at a position lower than the air vent hole 222. Thereby, the air in the cabin 1 that has entered from the air vent hole 222 can be discharged from a position lower than the air vent hole 222.

[0122] Discharging air from a position lower than the air vent hole 222 is because when air is discharged from a position at the same height or a higher position as the air vent hole 222, rainwater, foreign matters, etc. are likely to enter the air vent hole 222 through the portion where the air of the water stop cover 223 is discharged. In this regard, if it is a structure that discharges air from a position lower than the air vent hole 222, it is difficult for rainwater, foreign matters, etc. to enter. That is, by providing the 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 from the air vent hole 222.

[0123] In addition, by providing the water stop cover 223, it is possible to suppress not only the entry of water into the cabin 1 but also the entry of external noise into the cabin 1.

[0124] As shown in FIG. 18, the rear wall portion 221 has a rear plate portion 229 disposed behind the inclined wall portion 226. The rear plate portion 229 extends in the vertical direction behind the inclined wall portion 226. 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. Although FIG. 18 is a longitudinal sectional view, the portion within the large circle shows, in perspective view, the vicinity of the first hole 230 within the small circle shown in the longitudinal sectional view.

[0125] As shown in FIG. 17, a plurality (four in this embodiment) of the first holes 230 are formed in the rear wall portion 221 side by side in the left - right direction. A plurality (four in this embodiment) of the second holes 231 are formed in the rear plate portion 229 side by side in the left - right direction. Each of the plurality of second holes 231 is in a position overlapping each of the plurality of first holes 230 when viewed from the rear. In this embodiment, the closing plate 224 is fixed to the inclined wall portion 226 above the first hole 230 and can close the first hole 230. The second hole 231 is disposed behind the first hole 230, and the rear of the second hole 231 is covered by the water - stop cover 223.

[0126] In this way, by providing the rear plate portion 229 behind the inclined wall portion 226 provided with the first hole 230 and covering the rear of the second hole 231 provided in the rear plate portion 229 with the water - stop cover 223, it is possible to prevent water and foreign matters from entering the cabin 1 from the outside, and it is also possible to suppress the entry of outside noise into the cabin.

[0127] Further, the rear plate portion 229 has a first portion 229a provided with the second hole 231 and a second portion 229b provided below the first portion 229a and inclined so as to shift forward as it goes downward. In this way, by providing the second portion 229b inclined so as to shift forward as it goes downward below the first portion 229a provided with the second hole 231, the washing water sprayed from the rear during the washing of the cabin is the inclined second It is blocked by the portion 229b and cannot reach the second hole 231. Therefore, it is possible to prevent the cleaning water from entering from the second hole 231.

[0128] 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 portion of the first portion 229a. The front end of the third portion 229c is connected to an upward extension portion 226a that 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 forward and upward. The sixth portion 229f bends from the lower end of the fifth portion 229e and extends forward and downward. The vertical position of the lower end portion of the water stop cover 223 overlaps with the vertical position of the fourth portion 229d. The first portion 229a, the second portion 229b, and the third portion 229c are located above the lower end portion of the water stop cover 223.

[0129] With the above configuration, most of the cleaning water sprayed from the rear is prevented from entering inside the water stop cover 223 by the water stop cover 223. Among the cleaning water sprayed below the lower end of the water stop cover 223, the cleaning water hitting the fourth portion 229d partially bounces back upward, but the cleaning water moving upward hits the second portion 229b and falls. Among the cleaning water sprayed below the lower end of the water stop cover 223, the cleaning water sprayed below the fourth portion 229d hits the fifth portion 229e and falls.

[0130] In this way, not only the second portion 229b but also the fifth portion 229e exhibits the function of preventing the cleaning water from heading toward the upper second hole 231, so that it is possible to surely prevent the cleaning water from entering from the second hole 231. Further, since the rear plate portion 229 is bent at a plurality of locations as described above, the strength of the rear plate portion 229 can be improved as compared with the case where the rear plate portion 229 is in a flat plate shape.

[0131] As shown in FIG. 18, the exhaust system 220 of this embodiment forms a ventilation flow path 232 that discharges air to the outside of the cabin 1 through between the above-described first hole 230, second hole 231, and the water stop cover 223 and the rear surface of the rear wall portion 221. The ventilation flow path 232 is formed between the inclined wall portion 226 provided with the first hole 230 and the rear plate portion 229 provided with the second hole 231, and between the rear plate portion 229 and the water stop cover 223.

[0132] The air that has passed through the first hole 230 from the inside of 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.

[0133] In this way, the ventilation flow path 232 is formed in the space covered by the water stop cover 223. Therefore, while suppressing the intrusion of water and foreign substances into the cabin, the air inside the cabin can be exhausted to the outside.

[0134] Note 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 portion 221 are preferably set to be equal to or larger than the opening area of the first hole 230. When 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 is less than the amount of air that can pass through the first hole 230, so there is a risk of air stagnation. Also, when 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 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 portion 221 is less than the amount of air that can pass through the first hole 230, so there is a risk of air stagnation.

[0135] If the opening area of the second hole 231 and the flow path area of the water stop cover 223 are set to be equal to or larger than the opening area of the first hole 230, such air stagnation can be prevented. Therefore, air can be smoothly guided 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 in the cabin 1 can be reliably exhausted to the outside.

[0136] Also, the inclination angle of the closing plate 224 and the inclined wall portion 226 to which the closing plate 224 is attached with respect to the horizontal direction is preferably set to 20 to 45 degrees. By setting the inclination angles of the closing plate 224 and the inclined wall portion 226 with respect to the horizontal direction to 20 to 45 degrees in this way, even when the vehicle on which the cabin 1 is provided travels on a road surface inclined at an angle of 20 to 45 degrees with respect to the horizontal direction, the closing plate 224 will not be accidentally opened due to the inclination of the vehicle. Note that the inclination angle is not limited to 20 to 45 degrees and can be changed as appropriate.

[0137] The cabin 1 of the present invention includes door panels 27L and 27R arranged on the sides of the driver's seat 6, left and right side lower beams 19L and 19R (sometimes referred to as left and right side lower frames 19L and 19R) that support the rear portions of the door panels 27L and 27R from below and extend in an arc shape from the upper ends of the rear portions to the lower ends of the front portions, and left and right connecting frames 20L and 20R that support the front portions of the door panels 27L and 27R from below and extend forward from the lower ends of the left and right side lower beams 19L and 19R.

[0138] As shown in FIG. 19, a left connecting frame 20L is provided below the front portion of the left door panel 27L (see FIG. 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.

[0139] Hereinafter, the joining structure between the left connecting frame 20L and the left side lower beam 19L will be described with reference to the drawings. The same applies to the joining structure between the right connecting frame 20R and the right side lower beam 19R, which is not shown.

[0140] As shown in FIG. 21, in the case of a conventional cabin 501, a connecting frame 520 that connects the side lower beam 519 and the front pillar 13 abuts and joins against the front surface of the lower end portion of the side lower beam 519 from the front. In the case of such a joining structure, there may be variations in the joining accuracy with respect to the side lower beam 519 due to the influence of the dimensional tolerance of the length of the connecting frame 520. That is, since the connecting frame 520 is joined to the front surface of the lower end portion of the side lower beam 519 from the front, if there are variations in the length (length in the front-rear direction) of the connecting frame 520 due to dimensional tolerance, there will be variations in the joining accuracy.

[0141] On the other hand, as shown in FIG. 20, in the cabin 1 of the present invention, the lower end portion of the left side lower beam 19L is joined to the upper surface of the rear portion of the left connecting frame 20L. Although not shown, the lower end portion of the right side lower beam 19R is joined to the upper surface of the rear portion of the right connecting frame 20R.

[0142] In this way, since the lower end portion of the left side lower beam 19L (right side lower frame 19R) is joined to the upper surface of the rear portion of the left connecting frame 20L (right connecting frame 20R), the joining accuracy of the connecting frame 20L (right connecting frame 20R) with respect 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, the joining accuracy of the connecting frame 20L (right connecting frame 20R) with respect to the left side lower beam 19L (right side lower frame 19R) can be improved.

[0143] As shown in the enlarged part (the inner part shown as a circle) of FIG. 20, 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 linearly from the lower end of the curved portion 238 in the tangential direction of the arc of the curved portion 238 toward the front lower side. When the lower end of the curved portion 238 is indicated by point Q1, the tangent of the arc at point Q1 is X Q as shown. The portion provided along the tangent X Q below point Q1 is the straight portion 239, and the portion above point Q1 is the curved portion 238.

[0144] The virtual line X R in the figure is a line that hypothetically extends the curved portion 238 below point Q1. The virtual line X R indicates the front edge of the left side lower beam 19L when it does not have the straight portion 239. For the contact point Q2 where the virtual line X R contacts the upper surface of the connecting frame 20L, the contact point Q3 where the straight portion 239 (the tangent X Q ) contacts the upper surface of the connecting frame 20L is located forward by the length of ΔD. The contact point Q2 indicates the contact point between the front edge of the side lower beam 19L (the virtual line X R ) when it does not have the straight portion 239 and the connecting frame 20L.

[0145] Thus, the contact point Q3 between the front edge of the left side lower beam 19L having the straight portion 239 and the connecting frame 20L is located forward of the contact point Q2 between the front edge of the left side lower beam 19L without the straight portion 239 and the connecting frame 20L. Therefore, the contact area between the left side lower beam 19L having the straight portion 239 and the connecting frame 20L is larger than the contact area between the left side lower beam 19L without the straight portion 239 and the connecting frame 20L.

[0146] Therefore, in the cabin 1 of the present invention, the area of the seal portion with respect to the connecting frames 20L and 20R can be enlarged forward, and the joining strength between the side lower beams 19L and 19R and the connecting frames 20L and 20R can be improved. As a result, the strength of the side door frame can be greatly improved.

[0147] Note that the trailing 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. As a result, the lower portions of the left side lower beam 19L and the right side lower beam 19R widen toward the lower ends joined to the left connecting frame 20L and the right connecting frame 20R between the leading edge and the trailing edge. Therefore, the contact areas between the left side lower beam 19L and the right side lower beam 19R and the left connecting frame 20L and the right connecting frame 20R can be made sufficiently wide. Thereby, the joining strength between the side lower beams 19L, 19R and the connecting frames 20L, 20R can be improved.

[0148] Also, since the trailing 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) between the trailing edges and the left rear wheel 12L and the right rear wheel 12R can be ensured compared to the case where the trailing edges are straight lines parallel to the straight portion 239. Therefore, it becomes possible to accommodate various types (sizes) of the left rear wheel 12L and the right rear wheel 12R.

[0149] Thus, according to the joining structure between the side lower beams 19L, 19R and the connecting frames 20L, 20R of the above-described embodiment, the joining strength between the side lower beams 19L, 19R and the connecting frames 20L, 20R can be improved while ensuring a wider distance (clearance) between the side lower beams 19L, 19R and the left rear wheel 12L and the right rear wheel 12R.

[0150] Note that the boundary Q1 between the curved portion 238 and the straight portion 239 at the leading edge of the above-described left side lower beam 19L and right side lower beam 19R is preferably provided below the height Hs of the step mat 236. In other words, it is preferable that the straight portion 239 is provided below the upper surface of the step mat 236.

[0151] If the straight portion 239 is arranged below the upper surface of the step mat 236 in this way, the area of the seal 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, without narrowing the door width when the operator OP gets on and off. As a result, the strength of the door frame can be improved without impairing the boarding and alighting performance.

[0152] As shown in FIGS. 19 and 22, the lower part of the left front pillar 13L is connected to the front end portion of the connecting frame 20L. The left front pillar 13L is composed of a shaped tube. As shown in FIG. 23, the shaped tube 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 portions 13b, the third portions 13c, and the fourth portion 13d are formed as an integral body.

[0153] The first portion 13a is a surface facing the outside of 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 toward the inside of the cabin 1 in a direction approaching each other. The pair of third portions 13c extend from the respective ends of the pair of second portions 13b toward the inside of the cabin 1 in a direction away from each other. The fourth portion 13d is arranged so as to face the first portion 13a, and both end portions in the width direction are respectively arranged to abut against the pair of third portions 13c.

[0154] A bracket 257 is arranged inside the left front pillar 13L (on the side of the fourth portion 13d). The bracket 257 has a bracket body 257a, a reinforcing rib 257b, and a cylindrical body 257c. The bracket body 257a has 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 (substantially C - shape) in plan view. The first plate portion 257a1 extends above the second plate portion 257a2 and the third plate portion 257a3.

[0155] The reinforcing rib 257b is joined to the third plate portion 257a3. The reinforcing rib 257b extends upward beyond the second plate portion 257a2 and the third plate portion 257a3. Further, the reinforcing rib 257b extends upward beyond the first plate portion 257a1. The cylindrical body 257c is arranged surrounded on three sides by the first plate portion 257a1, the second plate portion 257a2, and the third plate portion 257a3.

[0156] As shown in FIGS. 22 and 23, the bracket 257 is disposed inside the left front pillar 13L (on the side of the fourth portion 13d) and joined to the front lower frame 256 and the connecting frame 20L. For the bracket 257, the first plate portion 257a1 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.

[0157] 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 upward beyond the second plate portion 257a2 and the third plate portion 257a3. Therefore, a large joining length (joining area) between the first plate portion 257a1 and the third portion 13c can be ensured. Thereby, the first plate portion 257a1 can be firmly joined to the left front pillar 13L.

[0158] The 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 upward beyond the second plate portion 257a2 and the third plate portion 257a3. Therefore, a large joining length (joining area) between the reinforcing rib 257b and the third portion 13c can be ensured. Thereby, the reinforcing rib 257b can be firmly joined to the left front pillar 13L.

[0159] As described above, since the first plate portion 257a1 and the reinforcing rib 257b can be firmly joined to the left front pillar 13L, the bracket 257 can be firmly joined to the left front pillar 13L. Here, since the reinforcing rib 257b extends upward beyond the first plate portion 257a1, the joining strength to the left front pillar 13L can be increased. Therefore, by providing the reinforcing rib 257b, the joining strength of the bracket 257 to the left front pillar 13L can be improved.

[0160] An air conditioner hose 241 extending in the vertical direction is inserted into the cylindrical body 257c. The air conditioner hose 241 extends downward inside the cylindrical body 257c and below the cabin 1. The air conditioner hose 241 extends in the vertical direction along the inner surface (the surface facing the inside 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 so as to sandwich the air conditioner hose 241. Therefore, the first plate portion 257a1 and the reinforcing rib 257b can function as guides for determining the direction of the air conditioner hose 241.

[0161] Although not shown, a bracket 257 is also arranged inside the right front pillar 13R (on the side of the fourth portion 13d) located at the right front of the cabin 1. The configuration (arrangement, etc.) of the right front pillar 13R, the connecting frame 20R, the front lower frame 256, the bracket 257, and the air conditioner hose 241 at the right front of the cabin 1 is the same as the configuration (arrangement, etc.) of the left front pillar 13L, the connecting frame 20L, the front lower frame 256, and the air conditioner hose 241 at the left front of the cabin 1.

[0162] In the cabin 1 of the present invention, a single panel material without joints is used for the front panel 31, and the weight of the front panel 31 increases. The load caused by the weight of the front panel 31 needs to be received at the front part of step 23. When the front panel is composed of panels separated vertically (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 on the front panel in the step was not large. However, when the front panel 31 is composed of a single panel material (in the case of the cabin 1 of the present invention), since the load of the front panel 31 is applied to step 23 without being dispersed, the load on the front panel in 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 part of the lower surface of step 23 (step plate) to reinforce step 23 (step plate) that constitutes the front floor of the cabin 1.

[0163] As shown in FIG. 28, the reinforcing bracket 240 includes a left reinforcing bracket 240L and a right reinforcing bracket 240R. The left reinforcing bracket 240L is joined to the left front part of the lower surface of step 23. The right reinforcing bracket 240R is joined to the right front part of the lower surface of step 23. The shapes of the left reinforcing bracket 240L and the right reinforcing bracket 240R are symmetric with respect to the center line in the width direction of the cabin 1 extending in the front-rear direction.

[0164] FIG. 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 the cross section cut in the front-rear direction is square. Step 23 is joined to the upper part of the reinforcing bracket 240. The front lower frame 256 (see FIG. 2) is joined to the front part of the reinforcing bracket 240. That is, the reinforcing bracket 240 is joined to both the front lower frame 256 arranged in the front and step 23 arranged above, and the three members cooperate to receive the load of the front panel 31.

[0165] As described above, the reinforcing bracket 240 is box-shaped (rectangular parallelepiped shape), and has a square cross-section when cut in the front-rear direction. Such a reinforcing bracket 240 has higher rigidity than a bracket formed by simply bending a part of a plate. Therefore, by joining such a reinforcing bracket 240 to the front part of step 23, the front part of step 23 can be effectively reinforced, and the load on the front panel 31 can be reliably supported at the front part of step 23.

[0166] As shown in FIGS. 24 and 25, the reinforcing bracket 240 has a bottom plate 250 disposed at a distance downward from the lower surface 23a of step 23. The bottom plate 250 is formed in a substantially rectangular plate shape that is long in the left-right direction. Front side plates 242F and rear side plates 242R extending in the vertical direction are provided at the front end and the rear end of the bottom plate 250. Further, a top plate 243 is provided between the upper ends of the front side plate 242F and the rear side plate 242R. That is, the reinforcing bracket 240 is formed in a rectangular tube shape extending in the left-right direction by the bottom plate 250, the front side plates 242F, the rear side plates 242R, and the top plate 243. Note that the reinforcing bracket 240 of the present embodiment has a top plate 243 and has a square cross-section when cut along the front-rear direction. Then, the upper surface of the top plate 243 is joined to the lower surface 23a of step 23.

[0167] However, the reinforcing bracket 240 may not have the top plate 243. In this case, the reinforcing bracket 240 is formed in a U-shaped (substantially C-shaped) cross-section that opens upward when cut along the front-rear direction. In this case, the upper part other than the top plate 243 (for example, the upper ends of the front side plates 242F and the rear side plates 242R) of the reinforcing bracket 240 is joined to the lower surface 23a of step 23.

[0168] As shown in FIGS. 24, 25, and 27, a vertical plate 244L extending upward toward the lower surface 23a is formed at the right end of the bottom plate 250 of the left reinforcing bracket 240L. The vertical plate 244L is provided so as to close an opening facing right of the left reinforcing bracket 240L formed in a square tube shape. As shown in FIG. 27, a vertical plate 244R extending upward toward the lower surface 23a is formed at the left end of the bottom plate 250 of the right reinforcing bracket 240R. The vertical plate 244R of the right reinforcing bracket 240R is provided so as to close an opening facing left of the right reinforcing bracket 240R formed in a square tube shape. In this way, the vertical plate 244L closes the right end of the left reinforcing bracket 240L, and the vertical plate 244R closes the left end of the right reinforcing bracket 240R. Hereinafter, the vertical plates 244L and 244R may be collectively referred to as the vertical plate 244.

[0169] As described above, the left reinforcing bracket 240L has a top plate 243 at the upper part, a bottom plate 250 at the lower part, a front side plate 242F at the front part, a rear side plate 242R at the rear part, and a vertical plate 244L at the right part. The left part of the left reinforcing bracket 240L is connected to the connecting frame 20L (see FIGS. 2 and 27). Thereby, in the left front part of the step 23, a space (hereinafter referred to as the bracket internal space) surrounded by the top plate 243, the bottom plate 250, the front side plate 242F, the rear side plate 242R, the vertical plate 244L of the left reinforcing bracket 240L, and the connecting frame 20L is formed.

[0170] Also, the right reinforcing bracket 240R has a top plate 243 at the upper part, a bottom plate 250 at the lower part, a front side plate 242F at the front part, a rear side plate 242R at the rear part, and a vertical plate 244R at the left part. The right part of the right reinforcing bracket 240R is connected to the connecting frame 20R (see FIG. 2). Thereby, in the right front part of the step 23, a space (hereinafter referred to as the bracket internal space) surrounded by the top plate 243, the bottom plate 250, the front side plate 242F, the rear side plate 242R, the vertical plate 244R of the right reinforcing bracket 240R, and the connecting frame 20R is formed.

[0171] By forming the above-described bracket internal space, vibrations and sounds transmitted from below the reinforcing brackets 240L and 240R toward the cabin are attenuated in the internal space, so that vibration suppression effects and sound insulation effects can be obtained.

[0172] Reinforcing ribs 245 are provided on the vertical plates 244 of the above-described left reinforcing bracket 240L and the vertical plates 244 of the right reinforcing bracket 240R. The reinforcing ribs 245 include a left reinforcing rib 245L that connects the vertical plate 244L on the right side of the left reinforcing bracket 240L and the lower surface 23a of the step 23, and a right reinforcing rib 245R that connects the vertical plate 244R on the left side of the right reinforcing bracket 240R and the lower surface 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.

[0173] The reinforcing rib 245 is a plate member that is substantially triangular when viewed from the front or the rear, and two are arranged, one each at the front end and the rear end of the vertical plate 244. By providing such reinforcing ribs 245, the rigidity of the reinforcing brackets 240L and 240R can be further improved, and the support strength of the step 23 with respect to the front panel 31 can be further improved.

[0174] As shown in FIGS. 25 and 26, the cabin 1 is provided with an air conditioner hose 241 for circulating refrigerant between the air conditioner 26 (see FIG. 1). The air conditioner hose 241 is arranged along a path passing outside the reinforcing bracket 240. Therefore, the air conditioner hose 241 is not arranged in the bracket internal space of the left reinforcing bracket 240L and the right reinforcing bracket 240R. Accordingly, it is not necessary to provide an opening for passing the air conditioner hose 241 in the left reinforcing bracket 240L and the right reinforcing bracket 240R. Therefore, the vibration suppression effect and the sound insulation effect obtained by providing the above-described bracket internal space are not hindered by the air conditioner hose 241.

[0175] As shown in FIG. 25, a left front pillar 13L is provided in front of the left side of the left reinforcement bracket 240L. The left front pillar 13L is a deformed pipe with a hollow interior, and an air conditioner hose 241 is inserted therein. The air conditioner hose 241 that exits the pipe outside from the lower end of the left front pillar 13L extends rightward along a path provided below the rear lower frame 17 in front of the reinforcement bracket 240, passes to the right of the vertical plate 244 of the left reinforcement bracket 240L, and is guided from a notch portion 100, which will be described later, into a heat exchanger such as a radiator provided in the bonnet.

[0176] Although not shown, the air conditioner hose 241 can also be inserted into the right front pillar 13R. In this case, the air conditioner hose 241 that exits the pipe outside from the lower end of the right front pillar 13R extends leftward along a path provided below the rear lower frame 17 in front of the reinforcement bracket 240, passes to the left of the vertical plate 244 of the right reinforcement bracket 240R, and is guided from a notch portion 100, which will be described later, into a heat exchanger such as a radiator provided in the bonnet.

[0177] When the air conditioner hose 241 is arranged in a path passing outside the reinforcement bracket 240 like this, the strength (rigidity) of the reinforcement bracket 240 can be increased compared to the case where the air conditioner hose is provided inside the reinforcement bracket. For example, when a structure for arranging the air conditioner hose is provided inside the reinforcement bracket, it becomes difficult to provide ribs (such as an internal rib 249, which will be described later) inside the reinforcement bracket 240 by the amount of the air conditioner hose arrangement, and the rigidity of the reinforcement bracket may decrease. In this regard, when the air conditioner hose 241 is arranged outside the reinforcement bracket 240, it becomes easy to provide the internal rib 249 and the like inside the reinforcement bracket 240, and the reinforcement bracket 240 can be made into a structure specialized only for reinforcement, so the strength in step 23 can be further improved.

[0178] As shown in FIG. 5, the cabin 1 of the present embodiment has a notch portion 10 at the lower center in the left - right direction. It is provided with a front panel 31 having 0. A portal-shaped opening frame 102 (see FIG. 4) is attached along the notch 100. The opening frame 102 has a shape along the opening of the notch 100 and is adhered to the peripheral edge of the opening, and is a member with high support strength. Therefore, if a member that connects the above-described reinforcing bracket 240 and the opening frame 102 to each other is provided, the support strength in step 23 can be further improved. Therefore, in the cabin 1 of the present embodiment, a connecting frame 246 that integrally connects the opening frame 102 and the reinforcing bracket 240 is provided between the opening frame 102 and the reinforcing bracket 240.

[0179] As shown in FIG. 25, the connecting frame 246 is integrally formed with the reinforcing bracket 240. Specifically, the connecting frame 246 is formed to rise upward from the inner end in the width direction of the top plate 243 of the reinforcing bracket 240. The end face of the connecting frame 246 in the direction facing the notch 100 (the face with the lead line of the reference numeral 246 attached) is formed in a triangular shape. Further, the end face of the connecting frame 246 in the direction facing the notch 100 is joined to the rear face of the opening frame 102 provided along the notch 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, so that the support strength by the reinforcing bracket 240 can be further improved.

[0180] As shown in FIG. 28, a plurality of attachment portions 248 for attaching a mount portion 247 that supports the cabin 1 from below are provided on the lower surface of the reinforcement bracket 240 at intervals in the front-rear direction. The mount portion 247 includes mount rubber or the like. In the case of the present embodiment, the attachment portion 248 is an insertion hole through which a bolt or the like can be inserted, and the mount portion 247 can be attached to the reinforcement bracket 240 using a bolt or the like. In the case of the illustrated example, two attachment portions 248 having two insertion holes in the left-right direction are provided on the lower surface of the reinforcement bracket 240 in two sets with their positions changed in the front-rear direction. By providing a plurality of attachment portions 248 at intervals in the front-rear direction in this way, the position where the mount portion 247 is attached can be changed in the front-rear direction, and the mounting position of the cabin can be shifted back and forth.

[0181] As a method for increasing the rigidity of the reinforcement bracket 240, an internal rib 249 can also be provided inside the reinforcement bracket 240. FIG. 29 shows an example of the reinforcement bracket 240 provided with the internal rib 249.

[0182] As shown in FIG. 29, the internal rib 249 is formed on the upper surface of the bottom plate 250 along the left-right direction and the front-rear direction. The internal rib 249 has a first rib 249a arranged to extend in the front-rear direction between the front side plate 242F and the rear side plate 242R, and a second rib 249b arranged between the front side plate 242F and the rear side plate 242R so as to be parallel to the front side plate 242F and the rear side plate 242R. The internal rib 249 of the present embodiment forms a lattice structure by combining the first rib 249a and the second rib 249b vertically and horizontally, and the rigidity of the reinforcement bracket 240 can be improved by integrating the bottom plate 250, the front side plate 242F, the rear side plate 242R, and the vertical plate 244 (and further the top plate 243 in the case of the present embodiment) using the first rib 249a and the second rib 249b. By providing such an internal rib 249 inside the reinforcement bracket 240, the rigidity of the reinforcement bracket 240 is further improved by the internal rib 249, and the support strength in step 23 can be further improved.

[0183] A preferred embodiment of the present invention provides a cabin 1 described in the following items.

[0184] (Item A1) A cabin 1 including a rear panel 32 disposed behind the driver's seat 6, a rear lower frame 17 disposed below the rear panel 32, and rear pillars 14 disposed 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 in a stepped manner toward the rear and is curved such that a central portion 17C descends downward with respect to both left and right ends 17L, 17R in the left-right direction.

[0185] According to the cabin 1 according to this Item A1, the angle formed by the rear pillar 14 and the rear lower frame 17 can be made larger than 90 degrees. Even when 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, and a decrease in sealing performance can be suppressed. Also, by making the angle formed by the rear pillar 14 and the rear lower frame 17 larger than 90 degrees, the visibility from the rear panel 32 toward the rear is also improved. Further, since the rear lower frame 17 is composed of the stepped member 202, it is easier to adjust the degree of curvature of the rear lower frame 17 compared to the case where the rear lower frame is composed of a square tube with high rigidity, and it is possible to easily adjust the angle formed by the rear pillar 14 and the rear lower frame 17.

[0186] (Item A2) A cabin 1 according to Item A1, including a rear lower glass (rear lower panel 200) disposed behind and below the driver's seat 6 and a support plate 208 that supports an upper portion of the rear lower glass (rear lower panel 200), wherein the support plate 208 is disposed so as to close an opening in front of the stepped member 202.

[0187] According to the cabin 1 related to this item A2, since the support plate 208 is arranged to close the opening in front of the stepped member 202, the rear lower frame 17 has a structure with a closed cross-section formed by the combination of the stepped member 202 and the support plate 208, and the strength (rigidity) can be greatly improved.

[0188] (Item A3) A weather strip 201 is provided between the rear panel 32 and the rear lower frame 17 and between the rear panel 32 and the rear pillar 14. The stepped member 202 has a first sealing surface 203 facing rearward and a second sealing surface 204 facing upward. The weather strip 201 is of a double-lip type including a main lip 201a and a sub-lip 201b. Between the rear panel 32 and the rear lower frame 17, the main lip 201a contacts the first sealing surface 203, and the sub-lip 201b contacts the second sealing surface 204, and the cabin 1 according to Item A1 or Item A2 is attached to the rear panel 32.

[0189] According to the cabin 1 related to this item A3, even if rainwater penetrates into the interior of the weather strip 201 over the sub-lip 201b of the weather strip 201, the rainwater that has penetrated through the space formed between the main lip 201a and the sub-lip 201b can be quickly drained downward.

[0190] (Item A4) A rear pillar cover 206 that covers the rear surface of the rear pillar 14 is provided on the rear pillar 14. The rear pillar cover 206 has a third sealing surface 210 on the end facing the rear panel 32, with which the sub-lip 201b of the weather strip 201 contacts. The rear surface of the rear pillar 14 and the first sealing surface 203 of the rear lower frame 17 are flush. 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. The cabin 1 according to Item A3.

[0191] According to the cabin 1 related to this item A4, among the seals of the weatherstrip 201, not only the main lip 201a but also the sub-lip 201b can be arranged side by side on a curve having a single radius of curvature, preventing excessive deformation of the weatherstrip 201 and preventing deterioration of the sealing performance.

[0192] (Item A5) Below the rear pillar 14, a fender cover 207 that covers the rear portions of the fenders 21L and 21R is provided. The fender cover 207 has a fourth seal surface 211 that contacts the sub-lip 201b of the weatherstrip 201 at an end facing the rear panel 32. The rear surface of the fender cover 207 and the first seal surface 203 of the rear lower frame 17 are flush. The cabin 1 according to item A3 or item A4, wherein the second seal surface 204 and the fourth seal surface 211 are provided side by side on a curve having a single radius of curvature.

[0193] According to the cabin 1 related to this item A5, among the seals of the weatherstrip 201, not only the main lip 201a but also the sub-lip 201b can be arranged side by side on a curve having a single radius of curvature, preventing excessive deformation of the weatherstrip 201 and preventing deterioration of the sealing performance.

[0194] (Item A6) The rear lower frame 17 has a protruding end face 202a that protrudes rearward, a lower surface 202b that is formed adjacent to the front portion of the protruding end face 202a and faces downward, a second seal surface 204 that is formed adjacent to the front portion of the protruding end face 202a and faces upward, a first seal surface 203 that is formed adjacent to the front portion of the second seal surface 204 and faces rearward, and an upper surface 202c that is formed adjacent to the front portion of the first seal surface 203 and faces upward. The upper surface 202c and the lower surface 202b are inclined surfaces that incline downward as they extend rearward, and the upper surface 202c is drawn to have an inclination angle with respect to the horizontal direction that is larger than that of the lower surface 202b. The cabin 1 according to item A3 or item A4.

[0195] According to the cabin 1 according to this item A6, since the upper surface 202c of the stepped member 202 (rear lower frame 17) is drawn so that the inclination angle with respect to the horizontal direction is larger than that of the lower surface 202b, by forming the inclined upper surface 202c that inclines rearward by drawing, it is possible to secure a rearward view, particularly a rearward and downward view, from the driver (operator OP) through the rear panel 32.

[0196] (Item A7) The rear lower frame 17 has a central portion 17C that curves with a first radius of curvature R1 and end portions 17L, 17R that curve with 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. The cabin 1 according to items A1 to A6.

[0197] According to the cabin 1 according to this item A7, by appropriately adjusting the radius of curvature R2 of the central portion 17C and the end portions 17L, 17R of the rear lower frame 17, the rear lower frame 17 can be smoothly connected to the rear pillar 14.

[0198] (Item A8) The cabin 1 according to item A7, in which the first radius of curvature R1 is formed larger than the second radius of curvature R2.

[0199] According to the cabin 1 related to this item A8, by making the 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.

[0200] (Item B1) A cabin 1 including a rear lower panel 200 disposed at the lower rear of the driver's seat 6 and a pair of side frames 205L and 205R disposed on the left and right of the rear lower panel 200, wherein the pair of side frames 205L and 205R are arranged to flare out as they go upward to the rear while supporting the left and right ends of the rear lower panel 200 over the entire vertical range.

[0201] According to the cabin 1 related to this item B1, since the pair of side frames 205L and 205R are formed to flare out as they go upward to the rear, a view that goes rearward through both upper corners of the rear lower panel 200 can be secured, and the rearward view can be widened. Also, since the pair of side frames 205L and 205R support the left and right ends of the rear lower panel 200 over the entire vertical range, it is possible to enhance the strength of the rear frame structure.

[0202] (Item B2) A cabin 1 according to item B1, comprising a rear lower frame 17 disposed along the upper end of the rear lower panel 200, a rear panel 32 disposed above the rear lower frame 17, and rear pillars 14L and 14R disposed on the left and right of the rear panel 32, wherein the upper ends of the side frames 205 are joined to the left and right ends 17L and 17R in the lateral direction of the rear lower frame 17, and both left and right ends 17L and 17R in the lateral direction of the rear lower frame 17 are respectively joined to the lower portions of the rear pillars 14.

[0203] ​According to the cabin 1 related to this item B2, since the upper end of the side frame 205 is joined to the left and right ends 17L, 17R in the left - right direction of the rear lower frame 17, and both the left and right ends 17L, 17R of the rear lower frame 17 are joined to the lower part of the rear pillar 14 respectively, the side frame 205 and the rear pillar 14 are arranged close to each other, and the strength of the frame structure of the cabin 1 is improved.

[0204] (Item B3) The cabin 1 according to item B1 or item B2, wherein the upper end of the side frame 205 is adjacent in the left - right direction to the lower part of the rear pillar 14.

[0205] According to the cabin 1 related to this item B3, since the upper end of the side frame 205 and the lower part of the rear pillar 14 are provided at positions adjacent in the left - right direction, a frame structure in which the side frame 205, the rear lower frame 17, and the rear pillar 14 are integrally joined is formed, so that the frame structure is less likely to be deformed, and the strength of the frame structure can be greatly improved.

[0206] (Item B4) The cabin 1 according to item B2 or item B3, comprising a rear lower glass (rear lower panel 200) disposed rear - lower of the driver's seat 6 and a support plate 208 that supports the upper part of the rear lower glass (rear lower panel 200), wherein the rear lower frame 17 has a stepped member 202 that protrudes step - by - step rearward, and the support plate 208 is disposed so as to close the opening in front of the stepped member 202 and is joined to both the side frame 205 and the rear pillar 14.

[0207] According to the cabin 1 related to this item B4, since the support plate 208 is disposed 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, the strength of the rear lower frame 17 can be increased, and cutting and joining operations can be easily performed.

[0208] (Item B5) On the outer sides of the side frames 205 in the left-right direction, fenders 21L and 21R that curve rearward as they go upward are arranged. The rear ends of the fenders 21L and 21R are joined to the lower part of the rear pillar 14. The stepped member 202 is joined to the rear ends of the fenders 21L and 21R, and the cabin 1 according to Item B4 described above.

[0209] According to the cabin 1 related to this Item B5, by joining the fenders 21L and 21R provided further outward in the left-right direction of the side frame 205 to the stepped member 202 with respect to the side frame 205 joined to the support plate 208, the four members of the rear pillar 14, the side frame 205, the rear lower frame 17, and the fenders 21L and 21R can be joined with high strength.

[0210] (Item B6) The upper surfaces of the rear parts of the fenders 21L and 21R are formed in an inclined shape that inclines upward as they go outward in the left-right direction, and the cabin 1 according to any one of Items B1 to B5.

[0211] According to the cabin 1 related to this Item B6, a space where a rearward view can be secured can be formed above the rear parts of the fenders 21L and 21R, and it becomes easy to secure a rearward view.

[0212] (Item C1) The cabin 1 includes a fuselage wall provided around the driver's seat 6, an air vent hole 222 opened in the fuselage wall, and a water stop cover 223 attached to the fuselage wall. The water stop cover 223 is arranged to cover the air vent hole 222 and forms a space with the lower part open between it and the fuselage wall.

[0213] According to the cabin 1 related to this item C1, with respect to the problems that have conventionally existed in a four-pillar type cabin, such as large indoor pressure fluctuations when the door is closed and the problem of the door being pushed back due to large pressure fluctuations, by using the air vent hole 222 to vent air from the indoor, the occurrence of the above-mentioned problems can be prevented. Further, by providing the water stop cover 223, it is possible to prevent water from entering the vehicle interior through the air vent hole 222.

[0214] (Item C2) The cabin 1 according to item C1, wherein the body wall has a rear wall portion 221 disposed behind the driver's seat 6, and the air vent hole 222 is provided in the rear wall portion 221.

[0215] According to the cabin 1 related to this item C2, among the front, rear, left, and right of the driver's seat 6, the air vent hole 222 can be provided at the rear where there is the least interference with other devices, and it is possible to prevent a decrease in the operability and habitability inside the cabin 1.

[0216] (Item C3) The cabin 1 according to item C1 or item C2, wherein the rear wall portion 221 is provided with a closing plate 224 for closing 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.

[0217] According to the cabin 1 related to this item C3, since the closing plate 224 is provided so as to be able to close the air vent hole 222, splashing water of high-pressure washing water, foreign matters, etc. can be surely blocked from entering the vehicle interior through the air vent hole 222.

[0218] (Item C4) The cabin 1 according to any one of items C1 to C3, wherein a plurality of the air vent holes 222 are provided side by side in the left-right direction, and a plurality of the closing plates 224 are provided so as to individually close the plurality of the air vent holes 222.

[0219] According to the cabin 1 related to this item C4, a plurality of air vent holes 222 can be individually closed by a closing plate 224 according to 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, making it possible to finely adjust the pressure inside the cabin 1.

[0220] (Item C5) The rear wall portion 221 has an inclined wall portion 226 that shifts rearward as it goes downward, and the air vent holes 222 are provided in the inclined wall portion 226. The closing plate 224 covers the air vent holes 222 from the upper surface side of the inclined wall portion 226. The cabin 1 according to item C2 or item C3.

[0221] According to the cabin 1 related to this item C5, the air vent holes 222 can be surely closed 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 set how much the air pressure inside the cabin 1 fluctuates before the closing plate 224 opens. Therefore, for example, when the air conditioner is operated to introduce outside air, the closing plate 224 does not open, and cold air or warm air is not wastedly exhausted. However, when the door is closed, it is possible to release the outside air and suppress the pressure fluctuation inside the cabin 1.

[0222] (Item C6) The rear wall portion 221 has a rear plate portion 229 that is disposed behind the inclined wall portion 226 and extends in the vertical direction. The air vent holes 222 have a first hole 230 provided in the inclined wall portion 226 and a second hole 231 provided in the rear plate portion 229. The closing plate 224 is capable of closing the first hole 230. The cabin 1 according to item C5.

[0223] According to the cabin 1 related to this item C6, the air in the cabin 1 can be guided to the water stop cover 223 through the first hole 230 provided in the inclined wall portion 226 and the second hole 231 provided in the rear plate portion 229, and the water stop cover 223 can prevent high-pressure washing water from entering the cabin 1 and prevent outside noise from entering the cabin 1.

[0224] (Item C7) The closing plate 224 has its upper end fixed to the rear wall portion 221 above the air vent hole 222, and when the pressure in the cabin 1 exceeds a predetermined pressure, it swings upward with the upper end as a fulcrum. The cabin 1 according to Item C2 or Item C3.

[0225] According to the cabin 1 related to this 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, the weight of the closing plate 224 itself can be utilized to reliably close the first hole 230. In addition, by changing the weight of the closing plate 224 itself, the predetermined pressure at which the closing plate 224 is opened can be adjusted. For example, when the air conditioner is operated to introduce outside air, the closing plate 224 will not open, and cold air and warm air will not be exhausted uselessly. However, when the door is closed, the closing plate 224 can be opened and closed to release outside air and suppress fluctuations in the air pressure inside the cabin 1.

[0226] (Item C8) The cabin 1 according to Item C6, in which a ventilation flow path 232 for discharging air from the cabin 1 to the outside is formed through the first hole 230, the second hole 231, and the space between the water stop cover 223 and the rear surface of the rear wall portion 221.

[0227] According to the cabin 1 related to this item C8, since a ventilation flow path 232 for discharging air from the cabin 1 to the outside is formed through the water stop cover 223, the air inside the cabin 1 can be exhausted to the outside while suppressing the intrusion of water and foreign matters.

[0228] (Item C9) 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. The cabin 1 according to item C8.

[0229] According to the cabin 1 related to this item C9, since the flow path area of the second hole 231 and the ventilation flow path 232 of the water stop cover 223 is set to be equal to or larger than the flow path area of the first hole 230, air can be guided along the ventilation flow path 232 from the first hole 230 to the second hole 231 and the water stop cover 223 without being retained, and the air in the cabin 1 can be reliably exhausted to the outside.

[0230] (Item C10) The cabin 1 according to item C5 that quotes item C3 in which the inclination angle of the closing plate 224 and the inclined wall portion 226 to which the closing plate 224 is attached with respect to the horizontal direction is 20 to 45 degrees.

[0231] According to the cabin 1 related to this item C10, even when the vehicle on which the cabin 1 is provided travels on a road surface inclined at an angle of 20 to 45 degrees with respect to the horizontal direction, the closing plate 224 will not be accidentally opened due to the inclination of the vehicle posture.

[0232] (Item C11) The cabin 1 according to any one of items C3 to C10, wherein the closing plate 224 has a rib portion 233 extending along the left-right direction at the rear end.

[0233] According to the cabin 1 related to this item C11, since the rib portion 233 extending along the left-right direction is formed on the closing plate 224, the warping and deformation of the closing plate 224 are suppressed by the rib portion 233, and problems such as the air vent hole 222 not being reliably closed due to the warped and deformed closing plate 224 can be avoided.

[0234] (Item C12) The rear plate portion 229 has a first portion 229a provided with the second hole 231, and a second portion 229b provided below the first portion 229a and inclined so as to shift forward as it goes downward. The cabin 1 according to item C6.

[0235] According to the cabin 1 related to this item C12, since a first portion 229a provided with the second hole 231 and a second portion 229b provided below the first portion 229a and inclined so as to shift forward as it goes downward are formed, even if splashing water of high-pressure washing water or the like enters from the lower end of the water stop cover 223, since the ventilation flow path 232 is bent by the first portion 229a and the second portion 229b, the splashing water does not reach the inside of the cabin 1.

[0236] (Item D1) A door panel 27 arranged on the side of the driver's seat 6, and from below at the rear part of the door panel 27 A cabin 1 including a side rocker beam 19 that supports and extends in an arc shape from the upper end of the rear part to the lower end of the front part, and a connecting frame 20 that supports the front part of the door panel 27 from below and extends forward from the lower end part of the side rocker beam 19, wherein the lower end part of the side rocker beam 19 is joined to the upper surface of the rear part of the connecting frame 20.

[0237] According to the cabin 1 related to this item D1, since the lower end part of the side rocker beam 19 is joined to the upper surface of the rear part of the connecting frame 20, there is no variation in the joining accuracy with respect to the side rocker beam 19 due to the influence of the dimensional tolerance of the length of the connecting frame 20. Therefore, the joining accuracy between the members constituting the door width can be improved.

[0238] (Item D2) The front edge of the side rocker beam 19 has a curved portion 238 curved in an arc shape, and a straight portion 239 extending linearly in the tangential direction of the arc of the curved portion 238 from the lower end of the curved portion 238 toward the front lower side. The cabin 1 according to item D1.

[0239] According to the cabin 1 related to this item D2, since a straight portion 239 extending linearly in the tangential direction of the arc of the curved portion 238 is provided at the front edge of the side lower beam 19, compared with a conventional cabin in which the lower end portion of the side lower beam 19 is formed only by the curved portion 238, the area of the seal portion with respect 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.

[0240] (Item D3) The cabin 1 according to item D2, wherein the rear edge of the side lower beam 19 is arcuately curved behind the straight portion 239.

[0241] According to the cabin 1 related to this item D3, since the rear edge of the side lower beam 19 is arcuately curved behind the straight portion 239, it is possible to correspond to various types of tires, and a seal portion with a wide area can be provided between the straight portion 239.

[0242] (Item D4) The cabin 1 according to any one of items D1 to D3, wherein the distance between the front edge and the rear edge of the lower portion of the side lower beam 19 expands toward the lower end portion joined to the connecting frame 20.

[0243] According to the cabin 1 related to this item D4, since the distance between the front edge and the rear edge of the lower portion of the side lower beam 19 expands toward the lower end portion joined to the connecting frame 20, the area of the seal portion can be made sufficiently wide, and the strength of the door frame can be greatly improved.

[0244] (Item D5) The cabin 1 according to items D2 to D4, wherein a step mat 236 is provided on the upper portion of the connecting frame 20, and the straight portion 239 is provided below the upper surface of the step mat 236.

[0245] According to the cabin 1 related to this item D5, since the straight part 239 is arranged below the upper surface of the step mat 236, the area of the seal part can be widened without narrowing the distance along the left - right direction of the upper surface of the step mat 236, in other words, without narrowing the door width when the driver (operator OP) gets on and off. As a result, the strength of the door frame can be improved without impairing the boarding and alighting performance.

[0246] (Item E1) A cabin 1 including 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. A box - shaped reinforcing bracket 240 extending in the left - right direction is joined to the front part of the lower surface of the step plate (step 23).

[0247] According to the cabin 1 related to this item E1, by providing such a reinforcing bracket 240 on the step 23, the front part of the step 23 can be reinforced, and it becomes possible to reliably support the load of the front panel 31 on the step 23.

[0248] (Item E2) The cabin 1 according to item E1, wherein the reinforcing bracket 240 has a square - shaped cross - section when cut in the front - rear direction.

[0249] According to the cabin 1 related to this item E2, since the cross - section of the reinforcing bracket 240 cut in the front - rear direction is square - shaped, the step 23 can be reinforced with the reinforcing bracket 240 having strong rigidity in terms of shape, and it becomes possible to improve the support strength of the step 23.

[0250] (Item E3) The cabin 1 according to item E1, wherein the reinforcing bracket 240 has a cuboid shape.

[0251] According to the cabin 1 related to this item E3, since a cuboid - shaped one that can ensure high rigidity is used as the reinforcing bracket 240, it becomes possible to surely improve the support strength of the step 23.

[0252] (Item E4) The cabin 1 according to any one of Items E1 to E3, in which an air conditioner hose 241 for circulating a refrigerant between the air conditioner is arranged along a path passing outside the reinforcing bracket 240.

[0253] According to the cabin 1 related to this Item E4, since the air conditioner hose 241 is arranged in a path passing outside the reinforcing bracket 240, there is no need to provide a structure (such as an opening or a notch) for passing the air conditioner hose 241 inside the reinforcing bracket 240, and the reinforcing bracket 240 can be made into a structure specialized only for reinforcement, and it is possible to further improve the support strength in Step 23.

[0254] (Item E5) The reinforcing bracket 240 has a bottom plate 250 arranged at a distance below the lower surface 23a (the lower surface 23a of Step 23) and a vertical plate 244 extending from the bottom plate 250 toward the lower surface 23a, and a reinforcing rib 245 connecting the vertical plate 244 and the lower surface 23a is provided. The cabin 1 according to any one of Items E1 to E4.

[0255] According to the cabin related to this Item E5, the rigidity of the reinforcing bracket 240 is further improved by the reinforcing rib 245, and it is possible to further improve the support strength in Step 23.

[0256] (Item E6) The reinforcing bracket 240 includes a left reinforcing bracket 240L joined to the left part of the lower surface 23a and a right reinforcing bracket 240R joined to the right part of the lower surface 23a. The reinforcing rib 245 includes a left reinforcing rib 245L connecting the vertical plate 244L on the right side of the left reinforcing bracket 240L and the lower surface 23a, and a right reinforcing rib 245R connecting the vertical plate 244R on the left side of the right reinforcing bracket 240R and the lower surface 23a. The cabin 1 according to any one of Items E1 to E5. 4R and the lower surface 23a.

[0257] According to the cabinet 1 related to this item E6, a left reinforcing bracket 240L joined to the left part of the lower surface 23a and a right reinforcing bracket 240R joined to the right part of the lower surface 23a are provided respectively. Therefore, both the left and right sides of step 23 can be reinforced in the same way, and the support strength of the front panel 31 by step 23 can be improved evenly in the left - right direction.

[0258] (Item E7) Inside the reinforcing bracket 240, an internal rib 249 connecting the inner wall of the reinforcing bracket 240 and the lower surface 23a is provided. The cabinet 1 according to Items E1 to E6.

[0259] According to the cabinet 1 related to this item E7, the rigidity of the reinforcing bracket 240 is further improved by the internal rib 249, and it becomes possible to further improve the support strength of step 23.

[0260] (Item E8) The front panel 31 has a notch 100 in the central lower part in the left - right direction. In the notch 100, an opening frame 102 having a shape along the opening of the notch 100 and adhered to the periphery of the opening is arranged. Between the opening frame 102 and the reinforcing bracket 240, a connecting frame 246 for integrally connecting the opening frame 102 and the reinforcing bracket 240 is provided. The cabinet 1 according to any one of Items E1 to E7.

[0261] According to the cabinet 1 related to this item E8, since the reinforcing bracket 240 and the opening frame 102 are integrally connected by the connecting frame 246, it becomes possible to further improve the support strength of step 23.

[0262] (Item E9) On the lower surface of the reinforcing bracket 240, a plurality of mounting portions 248 for mounting a mount portion 247 that supports the cabinet 1 from below are provided at intervals in the front - rear direction. The cabinet 1 according to any one of Items E1 to E8.

[0263] According to the cabin 1 related to this item E9, since a plurality of mounting portions 248 for attaching a mounting portion 247 that supports the cabin 1 from below are provided at intervals in the front-rear direction on the lower surface of the reinforcing bracket 240, the position for attaching the mounting portion 247 can be arbitrarily changed, and the mounting position of the cabin 1 with respect to the airframe 3 can be adjusted back and forth.

[0264] As described above, the present invention has been described. However, it should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

Explanation of reference numerals

[0265] 1 Cabin 6 Driver's seat 19 Side sill 20 Connecting frame 27 Door panel 236 Step mat 238 Curved portion 239 Straight portion OP Operator

Claims

1. A cabin comprising a door panel disposed on the side of a driver's seat, a side rocker beam that supports the rear part of the door panel from below and extends in an arc shape from the upper end of the rear part toward the lower end of the front part, and a connecting frame that supports the front part of the door panel from below and extends forward from the lower end of the side rocker beam, wherein the lower end of the side rocker beam is joined to the upper surface of the rear part of the connecting frame Cabin.

2. The front edge of the side rocker beam has a curved portion curved in an arc shape, and a straight portion extending linearly in the tangential direction of the arc of the curved portion from the lower end of the curved portion toward the lower front The cabin according to Claim 1.

3. The rear edge of the side rocker beam is curved in an arc shape behind the straight portion The cabin according to Claim 2.

4. The cabin according to Claim 1, wherein the distance between the front edge and the rear edge of the lower part of the side rocker beam expands toward the lower end joined to the connecting frame.

5. A step mat is provided on the upper part of the connecting frame, and the straight portion is provided below the upper surface of the step mat The cabin according to Claim 2.

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