JP6585010B2 - Inside air discharge device - Google Patents

Description

  The present invention relates to an inside air discharge device that discharges air in a cabin of a work machine.

2. Description of the Related Art Conventionally, in a working machine having a cabin such as a tractor, an inside air discharge device is known for discharging air inside a cabin to the outside when the cabin internal pressure rises due to an outside air introduction operation of an air conditioner or the like.
The inside air discharge device disclosed in Patent Literature 1 includes a top wall, a pair of first side walls, a pair of second side walls, an inside air discharge port, and a blocking plate. An intake port (inside air intake window) for taking in the inside air is formed in the first side wall, and the intake plate is opened when the closing plate swings inward when the internal pressure of the cabin rises. Thereby, the air (inside air) in the cabin is introduced from the intake port and is discharged to the outside from the inside air discharge port, and the internal pressure of the cabin is reduced.

JP 2010-132175 A

In a working machine such as a tractor, it may be required to maintain the cabin internal pressure at a set value or higher. In order to satisfy the requirement in the disclosed technique, it is conceivable to reduce the area of the intake. However, if the area of the intake port is reduced, the inside air of the cabin is not easily discharged, and the internal pressure may be excessive.
Accordingly, an object of the present invention is to provide an inside air discharge device that does not perform exhaust until the internal pressure of the cabin of the work implement reaches a set value, and can perform exhaust when the internal pressure exceeds the set value. To do.

An inside air discharge device according to an aspect of the present invention includes a side wall in which an intake port for taking in air in a cabin of a work machine is formed, and a discharge unit that discharges air taken in from the intake port. A case, a mounting part attached to the side wall, and a swinging part that is swingably provided with respect to the mounting part and opens and closes the intake port by swinging in accordance with an increase or decrease in internal pressure of the cabin; The swinging portion is formed to face the intake port, and is formed on the intake side and receives the internal pressure, and on the opposite side of the pressure receiving surface. And a projecting portion that is formed and projects into the case, wherein the pressure receiving surface is in contact with the inner surface of the side wall above the intake port, and the inner surface of the side wall below the intake port The lower part that contacts the And the upper portion and the lower portion are connected to each other in a straight line, and the projecting portion extends from the inner surface formed on the inner side of the case to the inlet side from the lower portion of the inner surface. A first transition portion that transitions downward, and a second transition portion that transitions upward from the upper part of the inner surface toward the intake side, and further, the intake port as viewed from a direction orthogonal to the intake port And the overlapping portion and the portion surrounded by the pressure receiving surface, the inner surface, the first transition portion, and the second transition portion are solidly formed. .

  According to the inside air discharge device, since the swinging portion is formed to face the intake port and has the protruding portion, the protruding height of the protruding portion (the thickness of the swinging portion is not changed) without changing the area of the intake port. ) Can be adjusted to adjust the internal pressure at which the inlet is opened. That is, by adjusting the protruding height of the protruding portion, the intake is not closed and exhausted until the cabin internal pressure reaches the set value, but when the set value is exceeded, the intake is opened and the exhaust is exhausted. Can be performed.

It is a front view (figure seen from the width direction inner side of a working machine) of an inside air discharge device. It is a side view (figure seen from the back of a working machine) of an inside air discharge device. It is a bottom view of an inside air discharge device. FIG. 3 is a view taken in the direction of arrow A in FIG. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is an expanded view of an inside air discharge device. It is CC sectional view taken on the line of FIG. It is the DD sectional view taken on the line of FIG. It is the figure which looked at the movable plate from the inner surface side (case inner side). It is the figure which looked at the movable plate from the front or back (3rd side wall side or 4th side wall side). It is a BB line sectional view showing the state where the 1st movable plate and the 2nd movable plate rocked inward. It is a figure which shows the 1st example of a change of a movable plate. It is a figure which shows the 2nd example of a change of a movable plate. It is a figure which shows the 3rd example of a change of a movable plate. It is a figure which shows the example of a change of an inside air discharge device. It is a longitudinal cross-sectional view of the vicinity of the rear wheel fender. It is the figure which looked at the 1st lever and the 2nd lever from the width direction inner side of a working machine. It is the figure which looked at the 1st lever and the 2nd lever from the back of a work implement. It is a longitudinal cross-sectional view which shows the attachment structure of a lower bonnet. It is a disassembled perspective view which shows arrangement | positioning, such as a radiator and a baffle plate. It is a side view of a working machine. It is a partial cross section top view of a working machine.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 17 is a side view of the tractor 1 exemplified as the work machine 1.
Hereinafter, the front side (left side in FIG. 17) of the driver seated on the driver's seat 8 of the tractor 1 is forward, the rear side (right side in FIG. 17) is rearward, and the left side of the driver (front side in FIG. 17) is forward. The left side and the right side of the driver (the back side in FIG. 17) will be described as the right side. Further, the horizontal direction K2 (see FIG. 18), which is a direction orthogonal to the front-rear direction K1 (see FIG. 17) of the tractor 1, will be described as the width direction. Further, description will be made assuming that the arrow K3 direction in FIG. 18 is outward in the width direction and the arrow K4 direction in FIG. 18 is inward in the width direction. The outward in the width direction is a direction from the center in the width direction of the tractor 1 toward the right or left. In other words, the outward in the width direction is the direction in the width direction K2 and away from the center in the width direction of the tractor 1. The inner side in the width direction is the direction opposite to the outer side in the width direction. In other words, the inner side in the width direction is the width direction K2 and a direction approaching the central portion in the width direction of the tractor 1.

The tractor 1 has a traveling vehicle body 4 configured by connecting an engine 2, a transmission case 3, and the like, left and right front wheels 6, and left and right rear wheels 7. A front axle frame 5 and a bonnet 11 are provided at the front portion of the traveling vehicle body 4.
The front axle frame 5 is provided so as to extend forward from the engine 2. The bonnet 11 is provided so as to be freely opened and closed, and an engine room is formed in the front portion of the traveling vehicle body 4. In the engine room, an engine 2, a radiator 12, an air cooling device, and the like are accommodated.

  A cabin 14 is mounted on the rear portion of the traveling vehicle body 4. A driver seat 8 is provided inside the cabin 14. As shown in FIG. 18, the driver's seat 8 is provided between a rear wheel fender 10 </ b> L covering the left rear wheel 7 and a rear wheel fender 10 </ b> R covering the right rear wheel 7. . A steering wheel 9 is provided in front of the driver's seat 8. A control unit 13 is provided on the right side of the driver's seat 8.

The cabin 14 includes a cabin frame 15, a ceiling member 16, and a bottom plate 17.
The cabin frame 15 is fixed to the traveling vehicle body 4. The cabin frame 15 includes a front strut 18, a rear strut 19, an intermediate strut 20, an upper lateral member 21, a lower lateral member 22, an upper rear member 23, a lower rear member 24, and the like. The front struts 18 are respectively provided on the left front and right front of the driver's seat 8. The rear struts 19 are provided at the left rear and right rear of the driver's seat 8, respectively. The intermediate struts 20 are provided between the left front strut 18 and the left rear strut 19, and between the right front strut 18 and the right rear strut 19, respectively. The upper horizontal member 21 connects the upper portion of the front strut 18, the upper portion of the rear strut 19, and the upper portion of the intermediate strut 20. The lower horizontal member 22 connects the lower part of the rear column 19 and the lower part of the intermediate column 20. The upper rear member 23 connects the upper portions of the left and right rear struts 19. The lower rear member 24 connects the lower portions of the left and right rear struts 19 to each other.

  A door 25 is supported on the intermediate column 20 so as to be rotatable about a vertical axis via a hinge. As for the door 25, the substantially whole surface is formed from glass. An entrance / exit is formed between the front post 18 and the intermediate post 20, and by opening the door 25, it is possible to move up and down from the entrance / exit into the cabin 14. A windshield is provided between the left and right front struts 18. A side glass 27 is provided between the intermediate column 20 and the rear column 19. A rear glass 28 that can be freely opened and closed is provided between the left and right rear columns 19.

The ceiling member 16 is provided on the cabin frame 15. The ceiling member 16 is configured by combining an outer roof and an inner roof, and an air conditioner device 30 is disposed therein. The inner roof facing the interior of the cabin 14 is formed with a number of air outlets for blowing air from the air conditioner 30 into the cabin 14.
The bottom plate 17 constitutes the bottom surface of the cabin 14 and connects the left rear wheel fender 10L and the right rear wheel fender 10R. The driver's seat 8 is supported on the upper surface of the rear portion of the bottom plate 17 via a floor seat 26.

As shown in FIG. 13, the rear wheel fender 10 </ b> R includes a rising portion 37 that rises upward from the bottom plate 17 on the inner side in the width direction of the rear wheel 7, and a horizontal plate portion 38 that is provided above the rear wheel 7. And an inclined portion 39 that connects the upper end of the rising portion 37 and the inner end in the width direction of the horizontal plate portion 38.
As shown in FIGS. 13 and 18, the control unit 13 is provided on the right side of the driver's seat 8. The control unit 13 is provided in the cabin 14 from above the lateral plate part 38 of the rear wheel fender 10R to the left side (inward in the width direction) of the rising part 37. Specifically, the control unit 13 includes an upper plate portion 41 provided above the horizontal plate portion 38 and extending to the left (inward in the width direction) with respect to the horizontal plate portion 38, and a left end of the upper plate portion 41 ( And a side plate portion 42 extending downward from the left end of the rising portion 37 from the inner end in the width direction.

  A plurality of operation levers (first lever 31 to sixth lever 36) are swingably provided in the control unit 13. The first lever 31 and the second lever 32 are provided at the rear part of the control unit 13. The third lever 33 to the sixth lever 36 are provided at the front part of the control unit 13. In the present embodiment, the first lever 31 is a draft lever. The second lever 32 is a position lever. The third lever 33 is a main transmission lever. The fourth lever 34 is an auxiliary transmission lever. The fifth lever 35 is a hand accelerator lever. The sixth lever 36 is an auxiliary control lever that operates the hydraulic equipment of the tractor 1. Note that the type, number, and arrangement of operation levers provided in the control unit 13 can be changed as appropriate.

A communication port 40 communicating with the outside of the cabin 14 is formed in the upper plate portion 41 of the control unit 13. The communication port 36 is provided inward in the width direction from the upper plate portion 38 of the rear wheel fender 10R. A room air discharge device 50 is installed on the upper surface of the upper plate portion 41. The inside air discharge device 50 is disposed at a position that covers the communication port 40 from above.
The inside air discharge device 50 is a device that discharges air (inside air) in the cabin 14 to the outside when the pressure (inside pressure) in the cabin 14 increases beyond a set value due to the outside air introduction operation of the air conditioner 30 or the like. .
<Inside air discharge device>
Hereinafter, the configuration of the inside air discharge device 50 will be described.

1 to 5 show a state in which the inside air discharge device 50 is assembled into a three-dimensional shape. FIG. 6 shows a state in which the inside air discharge device 50 is developed in a flat plate shape. First, the assembled state of the inside air discharge device 50 will be described with reference to FIGS.
The inside air discharge device 50 includes a case 51 and a movable plate 52 disposed inside the case 51.

First, the configuration of the case 51 will be described.
In the present embodiment, the case 51 includes a top plate 53, four side walls (a first side wall 54, a second side wall 55, a third side wall 56, and a fourth side wall 57), and a discharge unit 58.
The top plate 53 constitutes the upper part of the case 53 and is formed in a rectangular shape. The top plate 53 has four pairs (eight) pressing pieces 64. As will be described later, the pressing piece 64 is a portion that presses the upper end of the movable plate 52 against the inner surface of the side walls (the first side wall 54 and the second side wall 55). The pressing piece 64 protrudes downward from the lower surface of the top plate 53. Of the four pairs (eight) of pressing pieces 64, the first pair of pressing pieces 64 </ b> A is provided on the left front portion of the top plate 53. The second pair of pressing pieces 64 </ b> B is provided on the left rear portion of the top plate 53. The third pair of pressing pieces 64 </ b> C is provided at the right front portion of the top plate 53. The fourth pair of pressing pieces 64 </ b> D is provided at the right rear portion of the top plate 53.

  The first side wall 54, the second side wall 55, the third side wall 56, and the fourth side wall 57 constitute a side portion of the case 53. The first side wall 54 and the second side wall 55 are formed in a rectangular shape. The third side wall 56 and the fourth side wall 57 are formed in an isosceles trapezoidal shape whose upper side is longer than the lower side. Upper ends of the first side wall 54, the second side wall 55, the third side wall 56, and the fourth side wall 57 are connected to the four sides (outer edges) of the top plate 53, respectively. Specifically, the upper end of the first side wall 54 and the upper end of the second side wall 55 are respectively connected to two opposing sides of the top plate 53. The upper end of the third side wall 56 and the upper end of the fourth side wall 57 are connected to the remaining two sides facing the top plate 53, respectively. Thus, the first side wall 54 and the second side wall 55 are arranged to face each other, and the third side wall 56 and the fourth side wall 57 are arranged to face each other. Adjacent side walls (first side wall 54 and third side wall 56, second side wall 55 and third side wall 56, second side wall 55 and fourth side wall 57, first side wall 54 and fourth side wall 57) are connected to each other. Has been.

In the inside air discharge device 50, for example, the first side wall 54 is on the left side (width direction inner side), the second side wall 55 is on the right side (width direction right side), the third side wall 56 is on the front side, and the fourth side wall 57 is on the rear side. Each is facing and installed in the cabin 14. Hereinafter, for the sake of convenience, the inside air discharge device 50 will be described based on this installation state (direction), but the installation direction of the inside air discharge device 50 can be changed as appropriate.
As shown in FIGS. 2 and 5, the first side wall 54 and the second side wall 55 are inclined so as to be separated from each other as they move upward. The first side wall 54 and the second side wall 55 have an intake port 59 for taking the air in the cabin 14 into the case 51. In the present embodiment, the intake port 59 is formed in a substantially rectangular shape, but the shape of the intake port 59 is not limited, and may be, for example, a circle or an ellipse. The number of intake ports 59 is not limited, and for example, the intake ports 59 may be provided only on one of the first side wall 54 and the second side wall 55.

  A total of four support pins 63 are provided on the upper end portions of the first side wall 54 and the second side wall 55 on the inner surface side (inside the case 51). The first support pin 63 </ b> A is provided on the front side of the upper end portion of the first side wall 54. The second support pin 63 </ b> B is provided on the rear side of the upper end portion of the first side wall 54. The third support pin 63 </ b> C is provided on the front side of the upper end portion of the second side wall 55. The fourth support pin 63 </ b> D is provided on the rear side of the upper end portion of the second side wall 55. The support pin 63 protrudes toward the inside of the case 51. The first support pin 63A is sandwiched between the first pair of pressing pieces 64A. The second support pin 63B is sandwiched between the second pair of pressing pieces 64B. The third support pin 63C is sandwiched between the third pair of pressing pieces 64C. The fourth support pin 63D is sandwiched between the fourth pair of pressing pieces 64D. The support pin 63 and the pressing piece 64 are located above the intake port 59.

  On the inner surface of the first side wall 54 and the inner surface of the second side wall 55, sandwiching pieces 65 and 66 (an outer sandwiching piece 65 and an inner sandwiching piece 66) and a reinforcing rib 67 are provided, respectively. The sandwiching pieces 65 and 66 (the outer sandwiching piece 65 and the inner sandwiching piece 66) are provided at the front end portion and the rear end portion of the first side wall 54 and the front end portion and the rear end portion of the second side wall 55, respectively. Between the outer sandwiching piece 65 and the inner sandwiching piece 66, there are an edge (left edge and right edge) of the third side wall 56 and an edge (left edge and right edge) of the fourth side wall 57. It is pinched. Specifically, the left edge portion of the third side wall 56 is sandwiched between the outer clamping piece 65 and the inner clamping piece 66 provided at the front end portion of the first side wall 54. The right edge portion of the third side wall 56 is held between the outer holding piece 65 and the inner holding piece 66 provided at the front end portion of the second side wall 55. The left edge portion of the fourth side wall 56 is sandwiched between the outer clamping piece 65 and the inner clamping piece 66 provided at the rear end portion of the first side wall 54. The right edge portion of the third side wall 56 is held between the outer holding piece 65 and the inner holding piece 66 provided at the rear end portion of the second side wall 55.

A lower end portion of the inner holding piece 66 provided at the front end portion of the first side wall 54 and a lower end portion of the inner holding piece 66 provided at the rear end portion of the first side wall 54 are connected by a reinforcing rib 67. .
Locking holes 68 are respectively provided in the lower portions of the outer sandwiching pieces 65 of the first side wall 54 and the second side wall 55. The locking hole 68 passes through the outer clamping piece 65.
The third side wall 56 and the fourth side wall 57 have a mounting flange 60 and a connecting rib 61. The attachment flange 60 is a part attached to the upper plate portion 41 of the control portion 13. The mounting flange 60 is provided at the lower left part and the lower right part of the case 51, respectively. The left mounting flange 60 projects leftward from the lower end of the third side wall 56, and the right mounting flange 60 projects rightward from the lower end of the fourth side wall 57. The case 51 is fixed to the upper surface of the upper plate portion 41 by fastening the mounting flange 46 to the upper plate portion 41 of the control portion 13 by fastening with fasteners (bolts and nuts) 62.

Engagement protrusions 69 are provided below the outer end edge portions (left edge portion and right edge portion) of the third side wall 56 and the fourth side wall 57, respectively. As shown in FIG. 7, the engaging protrusion 69 is engaged with a locking hole 68 provided in the outer holding piece 65.
The discharge part 58 is a part for discharging the air taken into the case 51 from the intake port 59 to the outside of the case 51. The discharge part 58 is provided in the lower part of the case 53. The discharge part 58 is a rectangular opening part surrounded by the lower ends of the four side walls 54, 55, 56, 57. In a state where the case 51 is installed on the upper plate portion 41 of the control portion 13, the discharge portion 58 overlaps the communication port 40 of the upper plate portion 41. As a result, the air discharged from the inside of the case 51 to the outside of the case 51 through the discharge portion 58 is discharged to the outside of the cabin 14 through the communication hole 40. In addition, although not shown in figure, the discharge part 58 may be provided in the side part (for example, the 3rd side wall 56 or the 4th side wall 57) and upper part (for example, the top plate 53) of the case 51. In this case, the lower portion of the case 51 is closed by the bottom plate, and the position of the communication port 40 is provided at a position where the discharge portion 58 can be overlapped (for example, the side plate portion 42).

Hereinafter, based on FIG. 6, the state which expand | deployed the inside air discharge apparatus 50 is demonstrated.
In the present embodiment, the case 51 is integrally formed of synthetic resin. Specifically, as shown in FIG. 6, the case 51 is integrated with a synthetic resin in a state where the top plate 53, the first side wall 54, the second side wall 55, the third side wall 56, and the fourth side wall 57 are developed in a planar shape. Molded. The top plate 53 and the first side wall 54 are connected by a first connecting portion 71. The top plate 53 and the second side wall 55 are connected by a second connecting portion 72. The top plate 53 and the third side wall 56 are connected by a third connecting portion 73. The top plate 53 and the fourth side wall 56 are connected by a fourth connecting portion 74. The first connecting portion 71, the second connecting portion 72, the third connecting portion 73, and the fourth connecting portion 74 are more than the top plate 53, the first side wall 54, the second side wall 55, the third side wall 56, and the fourth side wall 57. It is thin and can be bent.

  The first connecting portion 71, the second connecting portion 72, the third connecting portion 73, and the fourth connecting portion 74 are bent so that the first side wall 54, the second side wall 55, the third side wall 56, After the fourth side wall 57 is raised, the edge of the side wall (the first side wall 54 to the fourth side wall 57) is sandwiched between the outer sandwiching piece 65 and the inner sandwiching piece 66, and the engagement projecting piece 69 is locked into the locking hole. By engaging with 68, the unfolded case 51 can be assembled into a three-dimensional shape. However, in the present invention, the case 51 is not limited to one integrally molded with a synthetic resin, and may be, for example, press molded with sheet metal.

Next, the configuration of the movable plate 52 will be described.
The movable plate 52 is attached to the side walls (the first side wall 54 and the second side wall 55) of the case 51, and swings according to the increase or decrease of the internal pressure of the cabin 14, thereby opening and closing the intake port 59.
The movable plate 52 is a separate member from the case 51 and is formed from a flexible or elastic material (bendable material) such as rubber or soft synthetic resin. Since the movable plate 52 is formed of a material having flexibility or elasticity, when the case 51 is made of a synthetic resin, a load of attaching the movable plate 52 to the case 51 is reduced. Further, when the movable plate 52 is formed of an elastic material such as rubber, it is possible to reduce the collision sound with the case 51 when the movable plate 52 is closed.

  As shown in FIGS. 5 and 6, in the present embodiment, the movable plate 52 includes a first movable plate 52A and a second movable plate 52B. The first movable plate 52 </ b> A opens and closes an intake port 59 formed in the first side wall 54. The second movable plate 52 </ b> B opens and closes an intake port 59 formed in the second side wall 55. In the present embodiment, the number of movable plates 52 is two, but the number of movable plates 52 is set corresponding to the number of intake ports 59. For example, when the intake port 59 is provided only in the first side wall 54, the movable plate 52 may be only the first movable plate 52A. When three or more intakes 59 are provided, three or more movable plates 52 are provided corresponding to the intakes 59.

  As shown in FIG. 5, the first side wall 54 and the second side wall 55, and the first movable plate 52 </ b> A and the second movable plate 52 </ b> B are orthogonal to the upper plate portion 41 of the control unit 13 and the first side wall 54. It is preferable to form symmetrically about the axis X passing through the middle with the second side wall 55. Thereby, the swing of the first movable plate 52A and the swing of the second movable plate 52B can be synchronized, and the discharge of the inside air can be performed stably.

Hereinafter, the configuration of the movable plate 52 will be described. A configuration common to the first movable plate 52A and the second movable plate 52B will be collectively referred to as a movable plate 52.
As shown in FIGS. 9A and 9B, the movable plate 52 includes an attachment portion 81 and a swinging portion 82. In the present embodiment, the entire movable plate 52 (the mounting portion 81 and the swinging portion 82) is formed solid, but may include a hollow portion.

  The attachment part 81 is a part attached to the side wall (the first side wall 54 and the second side wall 55) of the case 51. The attachment portion 81 is provided at the upper end portion of the movable plate 52. In the present embodiment, the attachment portion 81 is formed in a flat plate shape and has a plurality (two) of attachment holes 83. As shown in FIGS. 4 and 5, support pins 63 provided on the first side wall 54 and the second side wall 55 are inserted into the attachment holes 83. Specifically, the first support pin 63A and the second support pin 63B are inserted into the two mounting holes 83 of the first movable plate 52A, respectively. The third support pin 63C and the fourth support pin 63D are inserted into the two attachment holes 83 of the second movable plate 52B, respectively. The mounting portion 81 of the first movable plate 52A is supported by the first support pin 63A and the second support pin 63B, and the first side wall is supported by the first pair of pressing pieces 64A and the second pair of pressing pieces 64B. It is pressed against the inner surface of 54. In addition, the mounting portion 81 of the second movable plate 52B is supported by the third support pin 63C and the fourth support pin 63D, and is attached by the third pair of pressing pieces 64C and the fourth pair of pressing pieces 64D. 2 pressed against the inner surface of the side wall 55. Accordingly, the attachment portion 81 of the first movable plate 52A is attached above the intake port 59 inside the first side wall 54. The attachment portion 81 of the second movable plate 52B is attached above the intake port 59 inside the second side wall 55.

  The swing part 82 is a part provided facing the intake port 59 of the side walls (the first side wall 54 and the second side wall 55). The swing part 82 is provided so as to be swingable with respect to the attachment part 81. The swinging part 82 opens and closes the intake port 59 by swinging according to the increase or decrease of the internal pressure of the cabin 14. Specifically, the swinging portion 82 swings toward the inside of the case 51 to open the intake port 59 when the internal pressure of the cabin 14 increases due to the outside air introduction operation of the air conditioner 30 or the like. On the other hand, when the internal pressure of the cabin 14 decreases, the swinging part 82 swings toward the side wall (first side wall 54, second side wall 55) by its own weight, and comes into contact with the inner surface of the side wall to cause the intake port 59 to move. Close. The swing part 82 is provided below the attachment part 81.

  As shown in FIGS. 9A and 9B, the swinging portion 82 includes a pressure receiving surface 84 and a protruding portion 85. The pressure receiving surface 84 is a surface that receives the internal pressure of the cabin 14. In the present embodiment, the pressure receiving surface 84 is formed on the intake port 59 side. The pressure receiving surface 84 is formed larger than the intake port 59 so that the intake port 59 can be closed. The shape (outer shape) of the pressure receiving surface 84 is determined according to the shape of the intake port 59. In the present embodiment, the intake port 59 is formed in a substantially rectangular shape, and the pressure receiving surface 84 is formed in a substantially rectangular shape that is slightly larger than the intake port 59. In the present embodiment, the pressure receiving surface 84 is formed as a flat surface. Thereby, the pressure receiving surface 84 can receive the internal pressure of the cabin 14 substantially evenly.

  In the case of the present embodiment, the protruding portion 85 is formed on the side opposite to the pressure receiving surface 84 (inside the case 51) and protrudes toward the inside of the case 51. Although the specific shape of the protrusion part 85 is not limited, the protrusion part 85 of this embodiment includes an inner surface 86, a first transition part 87, a second transition part 88, a first side surface 89, and a second side surface 90. , Including. The inner surface 86 is a rectangular plane and is formed in parallel with the pressure receiving surface 84. The first transition portion 87 moves downward from the lower portion of the inner surface 86 toward (takes closer to) the intake port 59 side (pressure receiving surface 84 side). The second transition portion 88 moves upward from the upper part of the inner surface 86 toward (takes closer to) the intake port 59 side (pressure receiving surface 84 side). The first side surface 89 includes a front edge of the pressure receiving surface 84 (an edge on the third side wall 56 side), a front edge of the inner surface 86, a front edge of the first transition portion 87, and a front edge of the second transition portion 88. It is provided to connect. The second side surface 90 includes a rear edge of the pressure receiving surface 84 (an edge on the fourth side wall 57 side), a rear edge of the inner surface 86, a rear edge of the first transition portion 87, and a rear edge of the second transition portion 88. It is provided to connect. In the present embodiment, the first side surface 89 and the second side surface 90 are isosceles trapezoidal planes and are provided in parallel to each other.

  The protruding portion 85 is provided over the entire length of the swinging portion 82 in the lateral direction (the direction of the arrow K5 in FIG. 9A). When the protruding portion 85 is provided over the entire length in the lateral direction of the swinging portion 82, there is an advantage that the movable plate 52 can be efficiently manufactured. That is, in this case, when the movable plate 52 is manufactured, a long object having a length corresponding to a plurality of the movable plates 52 in the lateral direction is formed by a method such as extrusion, and then the long object is By cutting in a direction perpendicular to the direction, the plurality of movable plates 52 can be efficiently manufactured.

  In the present embodiment, the first transition portion 87 is an inclined surface (plane) that is inclined with respect to the pressure receiving surface 84 and the inner surface 86. By providing the first transition portion 87, as shown in FIG. 10, when both the first movable plate 52A and the second movable plate 52B swing toward the inside of the case 51, the first movable plate 52A The movable range until the lower portion and the lower portion of the second movable plate 52B interfere can be expanded. When the first transition portion 87 is an inclined surface (flat surface), the angle of the inclined surface is such that the first transition portion 87 of the first movable plate 52A and the first transition portion 87 of the second movable plate 52B are in surface contact. Is preferably set.

  In the present embodiment, the second transition portion 88 is also an inclined surface (plane) that is inclined with respect to the inner surface 86. The first transition portion 87 and the second transition portion 88 are formed symmetrically (line symmetric) with a central axis C1 passing through the center of the pressure receiving surface 84 interposed therebetween. In the present embodiment, the central axis C1 coincides with the central axis passing through the center of the inner surface 86. Specifically, the swinging portion 82 is formed in an isosceles trapezoidal shape when viewed from the first side surface 89 side and the second side surface 90 side. Thereby, since the weight balance of the rocking | swiveling part 82 becomes good, the rocking | swiveling part 82 can be rock | fluctuated stably. However, as shown in a modification example to be described later, the present invention includes the case where the first transition portion 87 and the second transition portion 88 are not inclined surfaces (planar surfaces) and those that are not symmetrical across the central axis C1.

  The protrusion 85 is taken in the range of 50% or more (more preferably 80% or more) of the area of the intake 59 as viewed from the direction orthogonal to the intake 59 (the direction along the dashed line C in FIG. 5). It preferably overlaps with the inlet 59. Accordingly, the internal pressure can be uniformly received by the swinging portion 82, and the taken-in air can be stably discharged because the movement of the swinging portion 82 is stabilized. In the present embodiment, the protruding portion 85 overlaps the intake port 59 in 100% of the area of the intake port 59 (entire area of the intake port 59). That is, the protrusion 85 is formed in a larger area than the intake port 59 when viewed from a direction orthogonal to the intake port 59.

  The swinging part 82 and the attaching part 81 are preferably formed integrally. By integrally forming the swinging portion 82 and the mounting portion 81, the swinging portion 82 can be stably swung. However, the swinging portion 82 may be formed separately from the mounting portion 81 (separate member) and then integrated with the mounting portion 81. When the mounting portion 81 and the swinging portion 82 are separated, the mounting portion 81 and the swinging portion 82 may be formed from different materials. In this case, at least the attachment part 81 should just be formed from the raw material which has flexibility or elasticity.

Since the swinging part 82 has the protruding part 85, the thickness (T2) of the swinging part 82 is larger than the thickness (T1) of the mounting part 81. In the present embodiment, the swinging portion 82 is formed integrally with the attachment portion 81 and thicker than the attachment portion 81.
The thickness (T1) of the attachment portion 81 is set to a bendable thickness (for example, about 0.5 to 1 mm). When the mounting portion 81 is bent, the swinging portion 82 swings with respect to the mounting portion 81. The thickness (T2) of the swinging portion 82 is determined according to the weight (self-weight) necessary for the swinging portion 82 to swing appropriately.

  When the internal pressure of the cabin 14 exceeds the set value, the swing part 82 swings toward the inside of the case 51 and opens the intake port 59. When the internal pressure of the cabin 14 is equal to or lower than the set value, the swinging portion 82 swings toward the side wall (the first side wall 54 and the second side wall 55), and closes the intake port 59 by contacting the inner surface of the side wall. To do. The set value of the internal pressure of the cabin 14 is set according to the specification of the tractor 1 and the like. For example, the differential pressure between the interior and the exterior of the cabin 14 when the air volume of the air conditioner 30 is set to the maximum is set in a range of 50 to 60 Pa.

  A force (pressing force) that is pushed inward (inside the case 51) by the internal pressure of the cabin 14 is applied to the pressure receiving surface 84 of the swinging portion 82. In addition, a force (restoring force) that tries to swing toward the side walls (the first side wall 54 and the second side wall 55) by its own weight also acts on the swinging portion 82. The pressing force acts in a direction to open the intake 59, and the restoring force acts in a direction to close the intake 59. The swing part 82 swings according to the balance (magnitude relationship) between the pressing force and the restoring force to open and close the intake port 59.

The magnitude of the restoring force can be adjusted by increasing or decreasing the thickness (T2) of the swinging portion 82. Specifically, when the swinging portion 82 is thickened and the weight is increased, the restoring force is increased. When the swinging portion 82 is thinned to reduce the weight, the restoring force is reduced.
The magnitude of the pressing force is determined by the set value of the internal pressure of the cabin 14 described above. Specifically, when the set value of the internal pressure is large, the pressing force increases. When the set value of the internal pressure is small, the pressing force is small.

Accordingly, when the set value of the internal pressure is large (when the pressing force is large), the restoring force is increased by increasing the weight by increasing the thickness of the swinging portion 82. When the set value of the internal pressure is small (when the pressing force is small), the restoring force is reduced by reducing the weight by thinning the swinging portion 82.
As described above, the balance between the pressing force and the restoring force is optimized by adjusting the thickness of the swinging portion 82 (the protruding height of the protruding portion 85) according to the set value of the internal pressure. As a result, the swinging part 82 opens the intake port 59 when the internal pressure of the cabin 14 exceeds the set value, and closes the intake port 59 when the internal pressure of the cabin 14 becomes equal to or lower than the set value.

  When the intake port 59 is opened, the air in the cabin 14 flows into the case 51 from the intake port 59, is discharged to the outside of the cabin 14 through the discharge portion 58 and the communication port 40, and the internal pressure of the cabin 14 is reduced. descend. When the internal pressure of the cabin 14 decreases and reaches a set value, the intake port 59 is closed, and the discharge of the air in the cabin 14 to the outside stops. Thereby, the internal pressure of the cabin 14 is maintained at a set value.

11A to 11C show a modification example of the movable plate 52. 11A to 11C are views of the movable plate 52 viewed from the front or rear (the third side wall side or the fourth side wall side), similarly to FIG. 9B. Hereinafter, only the difference between the movable plate of the modified example and the movable plate of the embodiment described above will be described.
FIG. 11A is a first modification of the movable plate 52. The movable plate 52 of the first modified example has a first transition part 87 and a second transition part 88 formed in a curved surface shape. Specifically, the 1st transition part 87 and the 2nd transition part 88 are formed in the curved surface which swells to the inner surface side (opposite side to the pressure receiving surface 84). The curved surfaces forming the first transition portion 87 and the second transition portion 88 are formed in an arc shape, for example. Although not shown, the first transition portion 87 and the second transition portion 88 may be formed so as to be recessed toward the pressure receiving surface 84 side.

FIG. 11B is a second modification of the movable plate 52. In the movable plate 52 of the second modified example, the first transition portion 87 and the second transition portion 88 are formed in a curved surface shape as in the first modified example, and in addition, the inner surface 86 is also an inner surface side (the pressure receiving surface 84 and It is formed in a curved shape that bulges to the opposite side. Thereby, the protrusion part 85 is formed in the circular arc shape convex to the inner surface side as a whole.
FIG. 11C is a third modification of the movable plate 52. In the movable plate 52 of the third modified example, the first transition portion 87 and the second transition portion 88 are formed asymmetrically across the central axis C1. Specifically, the distance from the first transition portion 87 to the central axis C1 is different from the distance from the second transition portion 88 to the central axis C1. Specifically, the first transition portion 87 is located farther from the central axis C1 than the second transition portion 88.

  As mentioned above, although the example of a change of the movable plate 52 was shown, the shape of the movable plate 52 is not limited to embodiment (including a change example) mentioned above. For example, in the above-described embodiment, the protruding portion 85 of the movable plate 52 is provided over the entire length in the lateral direction of the swinging portion 82 (the direction of the arrow K5 in FIG. 9A). (For example, only in the vicinity of the center in the horizontal direction) may be provided.

FIG. 12 shows a modified example of the inside air discharge device 50. 12 is a view corresponding to the cross-sectional view taken along the line BB of FIG. Hereinafter, only the different points of the modified internal air discharge device from the internal air discharge device of the above-described embodiment will be described.
The inside air discharge device 50 according to the modified example is partially different from the inside air discharge device according to the above-described embodiment in the configuration of the swinging portion 82 of the movable plate 52 (first movable plate 52A, second movable plate 52B). Specifically, the protruding portion 85 of the swinging portion 82 is formed on the intake 59 side. Further, the protruding portion 85 protrudes outside the case 51 in a state where the movable plate 52 closes the intake port 59. The outer surface of the protrusion 85 (the surface on the outside of the case 51) is a pressure receiving surface 84 that receives the internal pressure of the cabin 14. That is, in this modified example, the protrusion 85 has the pressure receiving surface 84.

  The shape of the protruding portion 85 is not particularly limited, but the movable plate 52 protrudes from the intake port 59 with the intake port 59 closed and does not protrude from the intake port 59 with the intake port 59 open (in the case 51). The shape can be retracted to the inside, and is determined in consideration of the balance between the pressing force and the restoring force described above. The amount of protrusion of the protrusion 85 from the intake port 59 is preferably reduced from the viewpoint of appearance and size (occupied space in the cabin 14). Specifically, as shown in FIG. 12, in the state where the movable plate 52 closes the intake port 59, the most outwardly projecting portion (maximum projecting portion) 85 a of the projecting portion 85 is the outer edge portion of the top plate 53. It is preferable to be located inward. FIG. 12 shows an imaginary line E extending downward from the outer edge of the top plate 53, and the maximum protrusion 85 a is located inward of the imaginary line E.

  In the inside air discharge device 50 of the above embodiment, the swinging portion 82 of the movable plate 52 is formed facing the intake port 59 of the case 51 and has a protruding portion 85. Therefore, the weight of the swinging portion 82 is optimized by adjusting the protruding amount (projecting height) of the protruding portion 85 according to the set value of the internal pressure of the cabin 14, and the balance between the pressing force and the restoring force described above. Can be optimized. Thereby, the swinging part 82 behaves so as to open the intake port 59 when the internal pressure of the cabin 14 exceeds the set value, and close the intake port 59 when the internal pressure of the cabin 14 becomes equal to or lower than the set value. That is, even if the area of the intake port 59 is not changed, the internal pressure at which the intake port 59 is opened can be adjusted only by adjusting the protruding amount of the protruding portion 85. As a result, the intake 59 is closed and exhaust is not performed until the internal pressure of the cabin 14 reaches a set value, and if the set value is exceeded, the intake 59 can be opened and exhausted.

As a method of increasing the weight of the swinging portion 82, the movable plate 52 can be formed from a flat plate having a large thickness and a constant thickness. In the present embodiment, the protruding portion 85 is provided on the swinging portion 82. By providing, the weight of the oscillating part 82 is increased. Accordingly, it is possible to reliably ensure the flexibility of the movable plate 52 and to swing the swinging portion 82 more stably.
Further, the swinging portion 82 of the movable plate 52 is formed on the intake port 59 side of the case 51 and formed on the pressure receiving surface 84 that receives the internal pressure of the cabin 14, on the opposite side of the pressure receiving surface 84, and in the case 51. And a protruding portion 85 that protrudes. Accordingly, the internal pressure of the cabin 14 can be stably received by the pressure receiving surface 84 opposite to the projecting portion 85, so that the movable plate 52 can be stably swung.

Further, the protrusion 85 overlaps the intake port 59 in a range of 50% or more of the intake area as viewed from the direction orthogonal to the intake port 59. Accordingly, the internal pressure can be uniformly received by the swinging portion 82 and the taken-in air can be discharged stably because the movement of the swinging portion 82 is stabilized.
The protrusion 85 has an inner surface 86 formed on the inner side of the case 51, a first transition portion 87 that moves downward from the lower portion of the inner surface 86 toward the inlet 59, and an inlet from the upper portion of the inner surface 86. And a second transition portion 88 that transitions upward toward the 59 side. As a result, the weight concentrates in the vicinity of the center of the projecting portion 85, so that the weight balance of the swinging portion 82 is improved, and the swinging portion 82 can be swung in a stable motion (a motion without variation).

  The pressure receiving surface 84 is a flat surface, and the inner surface 86 is formed parallel to the pressure receiving surface 84, and the first transition portion 87 and the second transition portion 88 pass through the center of the pressure receiving surface 84 and the center of the inner surface 86. They are formed symmetrically across the central axis C1. As a result, the internal pressure of the cabin 14 can be evenly received by the pressure receiving surface 84 and the weight balance of the swinging portion 82 becomes better, so that the swinging of the swinging portion 82 becomes more stable. Further, the adjustment (setting) of the weight of the swinging portion 82 can be easily performed.

The swinging part 82 is formed integrally with the attachment part 81 and thicker than the attachment part 81. Thereby, compared with the case where the attachment part 81 and the rocking | swiveling part 82 are formed separately, the intensity | strength of the movable plate 52 becomes high and can rock | fluctuate the rocking | swiveling part 82 by the stable motion.
The side wall includes a first side wall 54 and a second side wall 55 provided to face the first side wall 54, and the movable plate 52 opens and closes an intake port 59 formed in the first side wall 54. 1st movable plate 52A and 2nd movable plate 52B which opens and closes the intake port 59 formed in the 2nd side wall 55, The 1st movable plate 52A and the 2nd movable plate 52B have the 1st transition part 87. ing. As a result, the inside air of the cabin 14 can be taken into the case 51 from the two intake ports 59 and discharged to the outside. In addition, when the first movable plate 52A and the second movable plate 52B are swung toward the inside of the case 51, the movable range (swing range) until the lower portions interfere with each other can be widened.

Further, since the first movable plate 52A and the second movable plate 52B have the second transition portion 88, the weight balance between the first movable plate 52A and the second movable plate 52B becomes good, and the swinging portion is stabilized. And can be swung.
Further, since the first transition portion 87 and the second transition portion 88 are inclined surfaces that are inclined with respect to the inner surface 86, the movable range (oscillation) until the first movable plate 52A and the second movable plate 52B interfere with each other. Range) can be further widened, and the rocking portion 82 can be rocked more stably.
<Control lever>
As shown in FIGS. 13, 14 </ b> A, and 14 </ b> B, the first lever 31 (draft lever) and the second lever (position lever) 32 are attached to the shaft body 101. The shaft body 101 extends in the width direction K2 in parallel with the axle C2.

The lower end of the first lever 31 and the lower end of the second lever 32 are attached to the shaft body 101 side by side in the width direction K2. The first lever 31 and the second lever 32 swing in the front-rear direction with the shaft body 101 as a fulcrum.
The first lever 31 includes a first pivot portion 102, a first plate portion 103, a first grip portion 104, and a first shaft portion 105. The first pivot portion 102 is provided at one end (lower end) of the first lever 31. The first pivotal support portion 102 is formed in a cylindrical shape and is externally fitted to the shaft body 101. The first plate portion 103 is formed in an L shape and extends in two different directions from the outer surface of the first pivotal support portion 102. The first grip 104 is provided at the other end (upper end) of the first lever 31. The first grip 104 is a portion that is gripped by an operator seated on the driver's seat 8 during operation, and is fitted by a cover 131. The first shaft portion 105 is a rod-shaped portion that connects the first pivotal support portion 102 and the first gripping portion 104.

  The first shaft portion 105 has a lower portion 105D and an upper portion 105U. As shown in FIG. 15B, the lower portion 105D extends obliquely upward from the first pivotal support portion 102. Specifically, the lower portion 105D shifts outward in the width direction (in the direction in which the distance in the width direction from the second shaft portion 109 described later decreases) as it extends upward from the first pivotal support portion 102. The upper portion 105U extends upward from the upper end of the lower portion 105D.

As shown in FIG. 14B, the first grip 104 extends obliquely upward from the upper end of the upper portion 105U. Specifically, the first grip 104 moves inward in the width direction (the direction in which the distance in the width direction with the second shaft 109 described later increases) as it extends upward from the upper end of the first grip 104. .
The second lever 32 includes a second pivot part 106, a second plate part 107, a second grip part 108, and a second shaft part 109. The second pivot part 106 is provided at one end (lower end) of the second lever 32. The second pivotal support portion 106 is formed in a cylindrical shape and is fitted on the shaft body 101. The second pivotal support 106 is aligned with the first pivotal support 102 in the width direction K2. The second pivot part 106 is disposed outward in the width direction of the first pivot part 102. The second plate portion 107 is formed in an L shape and extends from the outer surface of the second pivotal support portion 106 in two different directions. The second grip 108 is provided at the other end (upper end) of the second lever 32. The second grip 108 is a portion that is held by the operator seated on the driver's seat 8 during operation, and is fitted by the cover 132. The second shaft portion 109 is a rod-shaped portion that connects the second pivotal support portion 106 and the second gripping portion 108.

  As shown in FIG. 14A, the second shaft portion 109 has a curved portion 110 that increases the distance in the front-rear direction (the operation direction of the first lever 31) with the first shaft portion 105. In the present embodiment, the bending portion 110 is bent forward. Specifically, the bending portion 110 moves forward (in the direction in which the distance in the front-rear direction from the first shaft portion 105 increases) as it extends upward from the first pivot support portion 102, and then rearward (the first shaft portion). 105 in the direction in which the distance in the front-rear direction with 105 becomes smaller. In other words, the curved portion 110 has a portion (referred to as the first portion 111) that moves forward (a direction in which the distance in the front-rear direction from the first shaft portion 105 increases) as it extends upward, and a rear portion (the first portion 111) as it extends upward. And a portion (referred to as a second portion 112) that transitions in the direction in which the distance in the front-rear direction from the one shaft portion 105 increases. The second portion 112 is provided above the first portion 111. A portion that does not shift forward or backward as it extends upward (a portion in which the distance in the front-rear direction from the first shaft portion 105 does not change) may be provided between the first portion 111 and the second portion 112. Good. In the present embodiment, the bending portion 110 is formed in an elliptical arc shape that is long in the vertical direction in a side view. Specifically, the curved portion 110 is formed in an elliptical arc shape in which the upper curvature radius is smaller than the lower curvature radius. The upper end of the bending portion 110 (the upper end of the second portion 112) is located above the upper end of the first shaft portion 105.

  As shown in FIG. 14B, the first portion 111 overlaps the first lever 31 (specifically, the first shaft portion 105) when viewed from the front-rear direction (the direction orthogonal to the shaft body 101 in the horizontal plane) A wrap portion 113). In other words, the first portion 111 includes a portion (overlap portion 113) in which the position in the front-rear direction is different from that of the first shaft portion 105, but the position in the width direction and the vertical direction are the same. The overlap portion 113 may be provided over the entire length of the first portion 111 or may be provided only in part. In the present embodiment, the overlap portion 113 is provided only at the lower portion of the first portion 111 and overlaps the lower portion of the upper portion 105U of the first shaft portion 105 as viewed from the rear. In the present embodiment, the first portion 111 shifts outward in the width direction (the direction in which the distance in the width direction from the first shaft portion 105 increases) as it extends upward.

  The second portion 112 extends obliquely upward from the upper end of the first portion 111. Specifically, the second portion 112 shifts outward in the width direction (in the direction in which the distance in the width direction from the first shaft portion 105 increases) as it extends upward from the upper end of the first portion 111. The second portion 112 does not overlap the first lever 31 when viewed from the front-rear direction (the direction orthogonal to the shaft body 101 in the horizontal plane).

  The second grip 108 extends obliquely upward from the upper end of the second portion 112. Specifically, the second grip 108 moves inward in the width direction as it extends upward from the upper end of the second grip 108. The second grip 108 is positioned above the first grip 104 and does not overlap the first lever 31 when viewed from the front-rear direction (the direction perpendicular to the shaft body 101 in the horizontal plane).

  According to the embodiment, since the first lever 31 and the second lever 32 attached to one shaft body 101 are arranged so as to overlap in the front-rear direction, the space occupied in the width direction can be reduced. it can. Specifically, in the conventional structure in which the first lever 31 and the second lever 32 are attached to one shaft body 101 side by side in the width direction, an arrangement space for two levers is required in the width direction. In the case of this embodiment, an arrangement space for one lever is sufficient above the overlap portion 113. In addition, since the second lever 32 includes the curved portion 110 that increases the distance in the front-rear direction (the operation direction of the first lever 31) from the first shaft portion 105, the first lever 31 and the second lever 32 are provided. Mutual interference with can be prevented. That is, when the first lever 31 is swung, it does not interfere with the second lever 32, and when the second lever 32 is swung, it does not interfere with the first lever 31.

That is, according to the lever structure of the present embodiment, the space occupied by the first lever 31 and the second lever 32 in the width direction inside the cabin 14 while avoiding mutual interference between the first lever 31 and the second lever 32. Can be reduced. In addition, the shape of the bending part 110 is not limited to the shape mentioned above. For example, the first shaft portion 105 of the first lever 31 may be disposed in front of the second shaft portion 109 of the second lever 32, and the bending portion 110 of the second shaft portion 109 may be bent backward.
<Bonnet structure>
As shown in FIG. 17, the bonnet 11 includes an upper bonnet 11U and a lower bonnet 11D. The upper bonnet 11U has an opening (grill) for taking in outside air at the front. As shown in FIG. 14, the lower bonnet 11 </ b> D is disposed below the upper bonnet 11 </ b> U and inward in the width direction of the front wheel 6. The upper end of the lower bonnet 11D is in contact with the sealing material 120 provided at the lower end of the upper bonnet 11U. The upper bonnet 11U and the lower bonnet 11D are in contact with each other via the sealing material 120, but are not integrated. The lower bonnet 11D extends downward from the lower end of the upper bonnet 11U, and is curved (inclined) so as to go inward in the width direction as it extends downward. In other words, the lower bonnet 11D is recessed toward the inner side in the width direction (the direction away from the front wheel 6) as it extends downward. This prevents the front wheel 6 from interfering with the hood 11 when the direction of the front wheel 6 is changed (when the front wheel 6 is turned off).

  When the bonnet 11 is a single body (when the bonnet 11 is not separated into the upper bonnet 11U and the lower bonnet 11D), when the lower portion of the bonnet 11 is recessed inward in the width direction, the bonnet 11 is opened upward. When doing so, the recessed portion may interfere with the equipment in the engine room. On the other hand, in the present embodiment, the upper bonnet 11U and the lower bonnet 11D are separated and the lower bonnet 11D is recessed, so that only the upper bonnet 11U is opened so that the recessed portion is in the engine compartment. Will not interfere with other devices.

  As shown in FIGS. 16 and 17, a radiator 12 is mounted on the front axle frame 5. An air cooling device (intercooler 44, oil cooler 45, receiver 46, condenser (not shown)), an air cleaner 121, and the like are provided in front of the radiator 12. The air cooling device is supported on the front axle frame 5 by the support frame 122. The support frame 122 is attached to a mounting plate 123 provided on the front axle frame 5.

  The radiator 12 is a pre-suction type that sucks air from the front and sends cooling air to the rear engine 2. An insect screen 47 is provided in front of the radiator 12. A rectifying plate 124 is provided on each of the left and right portions of the radiator 12. The rectifying plate 124 restricts air from being sucked into the radiator 12 from the side of the radiator 12. As shown in FIG. 15, the rectifying plate 124 is disposed inward in the width direction of the bonnet 11 and extends in the vertical direction. A mounting portion 125 made of a leaf spring is provided on the rectifying plate 124. The upper part of the current plate 124 is attached to a post frame 126 that supports the air cleaner 121 via an attachment part 125. A pivot pin 127 extending in the vertical direction (vertical direction) is provided at the lower portion of the current plate 124. The lower part of the rectifying plate 124 is pivotally supported with respect to the mounting plate 123 so as to be rotatable about the vertical axis by inserting a pivot pin 127 into a through hole 128 provided in the mounting plate 123. The rectifying plate 124 can be removed from the traveling vehicle body 4 by removing the mounting portion 125 from the post frame 126 and removing the pivot pin 127 from the through hole 128.

The lower bonnet 11D is attached to the current plate 124. Specifically, the lower portion of the lower bonnet 11D is attached to the lower portion of the rectifying plate 124 by fastening members (bolts 129 and nuts 130). Accordingly, the lower bonnet 11D can be detached from the traveling vehicle body 4 together with the current plate 124 (integrated with the current plate 124).
As described above, according to the bonnet structure of the present embodiment, the upper bonnet 11 and the lower bonnet 11D are separated, and the lower bonnet 11D is attached to the rectifying plate 124 that can be attached to and detached from the traveling vehicle body 4. Therefore, the lower bonnet 11D can be separated from the upper bonnet 11U and removed from the traveling vehicle body 4 together with the current plate 124. As a result, it is possible to easily perform maintenance of equipment (such as the radiator 12) in the engine room. Moreover, compared with the case where lower bonnet 11D is removed independently, possibility that the removed lower bonnet 11D will be lost is low. Further, when the lower bonnet 11D is attached to the traveling vehicle body 4, it can be attached integrally with the current plate 124. Therefore, attachment is easy compared with the case where the baffle plate 124 and lower bonnet 11D are attached separately.

  As mentioned above, although this invention was demonstrated, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Work implement (tractor)
14 Cabin 31 First Lever 32 Second Lever 50 Inside Air Discharge Device 51 Case 52 Movable Plate 52A First Movable Plate 52B Second Movable Plate 54 Side Wall (First Side Wall)
55 Side wall (second side wall)
58 discharge portion 59 intake port 81 attachment portion 82 swing portion 84 pressure receiving surface 85 protrusion portion 86 inner surface 87 first transition portion 88 second transition portion C1 central axis

Claims (5)

A case having a side wall formed with an intake port for taking in air inside the cabin of the work machine, and a discharge unit for discharging air taken in from the intake port;
A movable part having a mounting part attached to the side wall and a swinging part that is swingable with respect to the mounting part and opens and closes the intake port by swinging in accordance with an increase or decrease in the internal pressure of the cabin. A board,
The swinging portion is formed facing the intake port, is formed on the intake side and receives the internal pressure, is formed on the opposite side of the pressure reception surface, and protrudes into the case And a protruding portion that
The pressure receiving surface has an upper portion that contacts the inner surface of the side wall above the intake port, and a lower portion that contacts the inner surface of the side wall below the intake port, and the upper portion and the lower portion Is a plane that connects
The protrusion is
An inner surface formed on the inner side of the case;
A first transition portion that transitions downward from the lower surface of the inner surface toward the intake side;
A second transition portion that transitions upward from the upper surface of the inner surface toward the intake side;
Including,
The entire area of the intake port overlaps with the intake port as viewed from the direction orthogonal to the intake port, and is the overlapped portion and the pressure receiving surface, the inner surface, the first transition portion, the second The inside air discharge device in which the portion surrounded by the transition portion is solidly formed . The inner surface is formed in parallel with the pressure receiving surface,
2. The inside air discharge device according to claim 1, wherein the first transition portion and the second transition portion are formed symmetrically with a center axis passing through a center of the pressure receiving surface and a center of the inner surface . The inside air discharge device according to claim 1 or 2, wherein the swinging part is formed integrally with the attachment part and thicker than the attachment part . The side wall includes a first side wall and a second side wall provided opposite to the first side wall,
The movable plate includes a first movable plate that opens and closes the intake port formed in the first side wall, and a second movable plate that opens and closes the intake port formed in the second side wall,
The first movable plate and the second movable plate have the first transition portion and the second transition portion,
The first transition portion and the second transition portion are inclined surfaces inclined with respect to the inner surface,
When both the first movable plate and the second movable plate swing toward the inside of the case, the first transition portion of the first movable plate and the first transition portion of the second movable plate are The inside air discharge device according to any one of claims 1 to 3, which makes surface contact . The inside air discharge device according to any one of claims 1 to 3, wherein the first transition portion and the second transition portion are inclined surfaces inclined with respect to the inner surface .

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