Work vehicle

Abstract

The present invention provides a work vehicle that can suitably prevent a door from opening.　The work vehicle comprises: a cabin main body 10a; a door 30 turnably provided with respect to the cabin main body 10a; a first door damper 60 provided between the cabin main body 10a and the door 30; and a second door damper 70 provided between the cabin main body 10a and the door, and disposed at a different position from the first door damper 60 in the direction along the turning axis of the door 30. The work vehicle is configured such that in the state with the door 30 closed, the moment applied by the second door damper 70 to the door 30 in the direction of closing the door 30 is greater than the moment applied by the first door damper 60 to the door 30 in the direction of closing the door 30.

Description

Work vehicles

[0001] The present invention relates to work vehicle technology.

[0002] 2. Description of the Related Art Conventionally, technology for a work vehicle equipped with a cabin has been publicly known, as described in, for example, Japanese Patent Application Laid-Open No. 2003-222999.

[0003] Patent Document 1 describes a work vehicle equipped with a cabin having an opening / closing door for getting on and off. A damper is provided between the cabin and the opening / closing door to push the opening / closing door in the opening direction when the door is opened. Some such dampers can push the opening / closing door in the closing direction when the door is closed.

[0004] By providing the damper, the door can be prevented from opening when it is closed. However, the force with which the damper holds the door is relatively weak in areas away from the damper's installation position, so there is a risk that a portion of the door (e.g., the portion away from the damper) may unexpectedly open due to changes in pressure inside the cabin caused by the opening or closing of other doors. Therefore, a work vehicle that can effectively prevent doors from opening is desired.

[0005] JP 2018-144768 A

[0006] One aspect of the present disclosure has been made in consideration of the above-described circumstances, and the problem it aims to solve is to provide a work vehicle that can suitably prevent the door from opening.

[0007] The problem to be solved by one embodiment of the present disclosure has been described above, and next, the means for solving this problem will be described.

[0008] A work vehicle according to one aspect of the present disclosure includes a cabin body, a door rotatably mounted relative to the cabin body, a first door damper disposed between the cabin body and the door, and a second door damper disposed between the cabin body and the door at a position different from the first door damper in a direction along a rotation axis of the door, wherein, when the door is closed, a moment applied to the door by the second door damper in a direction to close the door is greater than a moment applied to the door by the first door damper in the direction to close the door. According to one aspect of the present disclosure, it is possible to prevent a portion of the door from opening unexpectedly.

[0009] The second door damper according to one aspect of the present disclosure is disposed above the first door damper, thereby effectively preventing the door from opening.

[0010] According to one aspect of the present disclosure, the first door damper and the second door damper are configured to apply a moment to the door in a direction to open the door within a first range of the door's pivotable range, and apply a moment to the door in a direction to close the door within a second range of the door's pivotable range, such that a ratio of the second range to the first range of the second door damper is greater than a ratio of the second range to the first range of the first door damper. According to one aspect of the present disclosure, the moment at which the second door damper closes the door can be greater than the moment at which the first door damper closes the door.

[0011] According to one aspect of the present disclosure, the first door damper and the second door damper are configured to be extendable and contractible and to return to their natural lengths, and the return force of the second door damper is configured to be greater than the return force of the first door damper. According to one aspect of the present disclosure, the moment at which the second door damper closes the door can be greater than the moment at which the first door damper closes the door.

[0012] The work vehicle according to one aspect of the present disclosure further includes a door handle provided on the door and positioned closer to the first door damper than the second door damper in a direction along the rotation axis of the door. According to one aspect of the present disclosure, the work vehicle according to one aspect of the present disclosure can prevent the portion of the door away from the door handle from opening unexpectedly.

[0013] According to one aspect of the present disclosure, the work vehicle further includes a reinforcing member provided on the door and positioned closer to the first door damper than the second door damper in a direction along the pivot axis of the door. According to one aspect of the present disclosure, the portion of the door away from the reinforcing member can be prevented from opening unexpectedly.

[0014] According to one aspect of the present disclosure, the first door damper and the second door damper are configured to be extendable and retractable and to return to their natural lengths, so that when the door is fully open, only one of the first door damper and the second door damper is at its natural length. According to one aspect of the present disclosure, rattle of the door in an open state can be prevented.

[0015] According to one aspect of the present disclosure, the door can be suitably prevented from opening.

[0016] FIG. 1 is a side view showing the overall configuration of a tractor according to one embodiment of the present disclosure; FIG. 2 is a perspective view showing a cabin body, a door, a first door damper, and a second door damper; FIG. 3 is an enlarged perspective view showing a cabin body, a door, a first door damper, and a second door damper; FIG. 4 is a right side view showing a left door; FIG. 5 is a plan view schematically showing a first door hinge and a first door damper; FIG. 6 is a plan view schematically showing a second door hinge and a second door damper; FIG. 7 is a schematic view showing the balance of the load applied to the door by the first door damper and the balance of the load applied to the door by the second door damper when the door is opened or closed;

[0017] In the following description, the directions indicated by arrows U, D, F, B, L, and R in the figures are defined as upward, downward, forward, backward, leftward, and rightward, respectively.

[0018] First, the overall configuration of a tractor 1 according to one aspect of the present disclosure will be described.

[0019] The tractor 1 shown in FIG. 1 mainly comprises a machine frame 2, an engine 3, a hood 4, a transmission case 5, front wheels 6, rear wheels 7, fenders 8, a lifting device 9, a cabin 10, a seat 20, a steering wheel 21, and the like.

[0020] The machine body frame 2 is a frame-shaped member formed by appropriately combining a plurality of plate materials. The machine body frame 2 is formed in a generally rectangular shape in a plan view. The machine body frame 2 is disposed at the front of the tractor 1 with its longitudinal direction facing the front-to-rear direction. An engine 3 is fixed to the rear of the machine body frame 2. The engine 3 is covered by a hood 4. A transmission case 5 is fixed to the rear of the engine 3.

[0021] The front portion of the vehicle frame 2 is supported by a pair of left and right front wheels 6 via a front axle mechanism (not shown). The rear portion of the transmission case 5 is supported by a pair of left and right rear wheels 7 via a rear axle mechanism (not shown). The pair of left and right rear wheels 7 are generally covered from above by fenders 8.

[0022] A lifting device 9 is provided at the rear of the transmission case 5. Various types of implements (e.g., a tiller) can be attached to the lifting device 9. The lifting device 9 can raise and lower the attached implements using an actuator such as a hydraulic cylinder. Power from the engine 3 can be transmitted to the lifting device 9 via a PTO shaft (not shown).

[0023] The power of the engine 3 is changed in speed by a transmission (not shown) housed in a transmission case 5, and then can be transmitted to front wheels 6 via the front axle mechanism, and to rear wheels 7 via the rear axle mechanism. The front wheels 6 and rear wheels 7 are driven to rotate by the power of the engine 3, allowing the tractor 1 to travel. The power of the engine 3 can also be used to drive a work device attached to the lifting device 9.

[0024] A cabin 10 is provided behind the engine 3. The cabin 10 is mounted on the vehicle body (transmission case 5, etc.). Inside the cabin 10, a living space for a driver is formed.

[0025] 1 and 2, the cabin 10 has left and right front pillars 12 that support a roof 11 at the front. The cabin 10 also has left and right rear pillars 13 that support the roof 11 at the rear. As shown in FIG. 2, the cabin 10 also has a front beam 14 that connects the upper ends of the front pillars 12 together. The cabin 10 also has a rear beam 15 that connects the upper ends of the rear pillars 13 together.

[0026] The cabin 10 also has upper side beams 16 that connect the upper ends of the left and right front pillars 12 and the left and right rear pillars 13. The cabin 10 also has fender frames 17 that extend downward and forward from the lower ends of the left and right rear pillars 13 and to which the fenders 8 are fixed. The fender frames 17 are curved to correspond to the shape of the fenders 8. The cabin 10 also has lower side beams 18 that connect the lower ends of the left and right front pillars 12 to the front ends of the left and right fender frames 17.

[0027] The above-mentioned front pillars 12, rear pillars 13, front beams 14, rear beams 15, upper side beams 16, fender frames 17 and lower side beams 18 constitute the structure of the cabin 10 (hereinafter referred to as the "cabin main body 10a").

[0028] As shown in Figure 1, a seat 20 for a driver is disposed approximately in the center of the cabin 10. An auxiliary step 20a for getting in and out of the seat 20 is provided on the lower part of the cabin 10 (lower side beam 18). The auxiliary step 20a is provided on at least the left side of the cabin 10. The auxiliary step 20a can be provided on both sides of the cabin 10. A steering wheel 21 for adjusting the turning angle of the front wheels 6 is disposed in the front part of the cabin 10.

[0029] As shown in Fig. 2, doors 30 are provided on both the left and right sides of the cabin 10, and are opened and closed when the driver gets in and out of the vehicle. The doors 30 are rotatably supported relative to the cabin body 10a. Figs. 2 and 3 show an example in which the left door 30 is open. Fig. 4 is a right side view of the left door 30. Since the left and right doors 30 are configured symmetrically, the following description will focus on the door 30 provided on the left side of the vehicle body, and a description of the right door 30 will be omitted.

[0030] The door 30 is formed to fit within a frame formed by the front pillars 12, rear pillars 13, upper side beams 16, fender frame 17, and lower side beams 18 of the cabin main body 10a. In a side view, the door 30 is formed in a generally rectangular shape that is long in the vertical direction, with the portion on the fender frame 17 side (the lower rear corner) cut out. The door 30 is formed by a glass plate and a frame that surrounds the outer edge of the glass plate.

[0031] 1 and 2, a door handle 31 is provided on the outer surface of the door 30 facing the cabin 10. The door handle 31 is gripped by the driver when opening or closing the door 30 from the outside. The door handle 31 is located midway up and down on the front side of the door 30. In the illustrated example, the door handle 31 is located slightly below the center of the door 30 in the up and down direction.

[0032] As shown in FIGS. 2 and 4 , a handrail 32 is provided on the inner surface of the door 30 facing the cabin 10, and is grasped by the driver when opening or closing the door 30 from the inside. The handrail 32 is formed of a rod-shaped metal member. The handrail 32 is disposed so as to extend diagonally upward and downward in approximately the lower half of the door 30. More specifically, the handrail 32 is disposed so as to extend along the fender frame 17. The handrail 32 is formed in a curved shape so as to generally correspond to the shape of the fender 8. An upper end of the handrail 32 is fixed to a first stay 41, which will be described later. A lower end of the handrail 32 is fixed to the front lower portion of the door 30 (below the door handle 31). By providing the handrail 32, the lower half of the door 30 is reinforced.

[0033] 2 and 3, the door 30 is provided rotatable about a rotation axis along the up-down direction relative to the cabin main body 10a via a first door hinge 40 and a second door hinge 50. The first door hinge 40 and the second door hinge 50 will be described below.

[0034] The first door hinge 40 shown in Figures 3 and 4 connects the rear lower portion of the door 30 to the lower portion of the rear pillar 13. The first door hinge 40 is formed in a shape that is long in the front-to-rear direction. The first door hinge 40 is provided to the lower portion of the rear pillar 13 so as to be rotatable about a rotation axis that is generally along the up-down direction. The first door hinge 40 is fixed so as to sandwich the glass plate portion of the door 30 in the thickness direction (see Figure 5).

[0035] 3 and 5, a first stay 41 extending inward (toward the center in the left-right direction of the vehicle body) is provided on the inside of the cabin 10 of the first door hinge 40. A first door damper 60 (described later) is connected to the tip of the first stay 41 in the extending direction.

[0036] The second door hinge 50 shown in Figures 3 and 4 connects the upper rear portion of the door 30 to the upper portion of the rear pillar 13. The second door hinge 50 is provided to be rotatable about a rotation axis that is generally along the up-down direction relative to the upper portion of the rear pillar 13. The rotation axis of the second door hinge 50 relative to the rear pillar 13 is disposed on approximately the same axis as the rotation axis of the first door hinge 40 relative to the rear pillar 13. The second door hinge 50 is disposed higher than the first door hinge 40. The configuration of the second door hinge 50 is generally similar to the configuration of the first door hinge 40, except for the second stay 51. Therefore, a description of the configuration of the second door hinge 50 excluding the second stay 51 will be omitted.

[0037] 3 and 6 is provided at a portion of the second door hinge 50 that is located inside the cabin 10. The second stay 51 extends toward the inside of the cabin 10 (toward the center in the left-right direction of the vehicle body). The extension dimension of the second stay 51 is greater than the extension dimension of the first stay 41. A second door damper 70, which will be described later, is connected to the tip of the second stay 51 in the extension direction.

[0038] 3, in this embodiment, a first door damper 60 and a second door damper 70 are provided between the door 30 and the cabin main body 10a. The first door damper 60 and the second door damper 70 will be described below.

[0039] The first door damper 60 shown in Figures 3 and 5 is provided between the first door hinge 40 and the fender frame 17. The first door damper 60 is extendable and contractible and configured to return to its natural length (maximum extended length). The first door damper 60 includes a cylinder tube 61, which is a cylindrical member filled with gas, and a piston rod 62, which is a substantially cylindrical member housed inside the cylinder tube 61. The piston rod 62 is biased in a direction that protrudes relative to the cylinder tube 61 (the direction in which the first door damper 60 extends) by receiving pressure from the gas inside the cylinder tube 61. The return force of the first door damper 60 can be set to a value of, for example, approximately 10 to 13 kgf.

[0040] The tip of a cylinder tube 61, which is one end of the first door damper 60, is connected to the tip of the first stay 41 of the first door hinge 40 so as to be rotatable about a rotation axis that extends generally in the vertical direction (see FIG. 5). The tip of a piston rod 62, which is the other end of the first door damper 60, is connected to the fender frame 17 so as to be rotatable about a rotation axis that extends generally in the vertical direction (see FIG. 3).

[0041] The second door damper 70 shown in FIGS. 3 and 6 is disposed between the second door hinge 50 and the upper side beam 16. That is, the second door damper 70 is disposed above the first door damper 60. The second door damper 70 is configured to be extendable and retractable in a manner similar to the first door damper 60 and to return to its natural length. The second door damper 70 includes a cylinder tube 71 and a piston rod 72 that are generally similar to the cylinder tube 61 and piston rod 62 of the first door damper 60. The natural length of the second door damper 70 is generally the same as that of the first door damper 60. The restoring force of the second door damper 70 is configured to be greater than that of the first door damper 60. The restoring forces (capacities) of the door dampers can be set by varying the amount of gas filled in them. The restoring force of the second door damper 70 can be set to, for example, approximately 20 to 30 kgf.

[0042] The tip of the piston rod 72, which is one end of the second door damper 70, is connected to the tip of the second stay 51 of the second door hinge 50 so as to be rotatable about a rotation axis that is generally along the vertical direction (see FIG. 6 ). The tip of the cylinder tube 71, which is the other end of the second door damper 70, is connected to the upper side beam 16 so as to be rotatable about a rotation axis that is generally along the vertical direction (see FIG. 3 ). In this manner, in this embodiment, the second door damper 70 is attached in the opposite direction to the first door damper 60 with respect to the door 30 and the cabin main body 10a.

[0043] As shown in FIG. 4 , in the tractor 1 configured as described above, the door handle 31 is disposed below the first door damper 60. The handrail 32 is disposed so as to extend downward from the portion where the first door damper 60 is provided. In this manner, the door handle 31 and the handrail 32 are disposed closer to the first door damper 60 in the up-down direction than the second door damper 70. Specifically, in a side view (see FIG. 4 ), assuming that the entire door area is divided into two by an imaginary line that passes through the midpoint between the first door damper 60 and the second door damper 70 and is perpendicular to the up-down direction (the direction of the rotation axis of the door 30), the door handle 31 and the handrail 32 are disposed in the area on the first door damper 60 side.

[0044] By providing the first door damper 60 and the second door damper 70 as described above, the door 30 can be opened and closed conveniently using the door handle 31 and the handrail 32. More specifically, the first door damper 60 and the second door damper 70 apply a moment (moment load) in the opening or closing direction of the door 30 as the door 30 is opened or closed, thereby improving the operability of opening and closing the door 30.

[0045] The following describes the operation of each door damper (first door damper 60 and second door damper 70) and the load balance of each door damper when the door 30 is closed (fully closed state) and open (fully open state) with reference to Figures 5 to 7. Note that Figures 5 and 6 schematically show the door 30 and each door damper as viewed in the direction of the rotation axis of the door 30. In Figures 5 and 6, the door 30 and each door damper in the fully closed state are indicated by solid lines, and the door 30 and each door damper in the fully open state are indicated by two-dot chain lines.

[0046] In the following description, the connection point between the door 30 (each door hinge) and the rear pillar 13 (the pivot axis of the door 30) will be referred to as "fulcrum A." Furthermore, the connection point between the first door damper 60 and the fender frame 17 (the pivot axis of the first door damper 60) will be referred to as "fulcrum B1," and the connection point between the second door damper 70 and the upper side beam 16 (the pivot axis of the second door damper 70) will be referred to as "fulcrum B2." Furthermore, the connection point between the first stay 41 (first door hinge 40) and the first door damper 60 will be referred to as "fulcrum C1," and the connection point between the second stay 51 (second door hinge 50) and the second door damper 70 will be referred to as "fulcrum C2."

[0047] First, the operation of the first door damper 60 will be described. When the door 30 is closed, as indicated by the solid line in FIG. 5 , the first door damper 60 slightly biases the door 30 in the closing direction due to its restoring force. As will be described later, the restoring force of the first door damper 60 contributes little to closing the door 30. When the door 30 is rotated in the opening direction, the first door damper 60 rotates around fulcrum B1 in conjunction with the rotation of the door 30 around fulcrum A. When the first door damper 60 rotates in this manner and passes a dead point, as will be described later, it extends due to its restoring force, biasing the door 30 in the opening direction. When the door 30 is fully open, as indicated by the two-dot chain line in FIG. 5 , the first door damper 60 is at its natural length (maximum extended length).

[0048] Next, the operation of the second door damper 70 will be described. In the closed state of the door 30 shown by the solid line in FIG. 6 , the second door damper 70 biases the door 30 in the closing direction by its restoring force. When the door 30 is rotated in the opening direction, the second door damper 70 rotates around fulcrum B2 in conjunction with the rotation of the door 30 around fulcrum A. When the second door damper 70 rotates in this manner and passes a dead point (described later), it extends by its restoring force, biasing the door 30 in the opening direction. In the fully open state of the door 30 shown by the two-dot chain line in FIG. 6 , the second door damper 70 biases the door 30 in the opening direction by its restoring force. In this embodiment, the second door damper 70 is configured so as not to reach its natural length when the door 30 is fully open.

[0049] 5 and 6, the second stay 51 extends further inward into the cabin 10 than the first stay 41, and therefore, when the door 30 is fully open, the fulcrum C2 of the second door damper 70 is located closer to the cabin 10 than the fulcrum C1 of the first door damper 60. Therefore, when the door 30 is fully open, the second door damper 70 is shorter than the first door damper 60, and so while the first door damper 60 reaches its natural length, the second door damper 70 does not reach its natural length.

[0050] In addition, in this embodiment, a difference is provided between the moment that the first door damper 60 applies to the door 30 and the moment that the second door damper 70 applies to the door 30. More specifically, in this embodiment, when the door 30 is closed, the moment that the second door damper 70 applies to the door 30 is configured to be greater than the moment that the first door damper 60 applies to the door 30.

[0051] In this embodiment, one method for making the moment applied to the door 30 by the second door damper 70 greater than the moment applied to the door 30 by the first door damper 60 when the door 30 is closed is to make the restoring force of the second door damper 70 greater than the restoring force of the first door damper 60, as described above.

[0052] Furthermore, in this embodiment, a method is adopted in which the balance of the loads applied to the door 30 by each door damper (the ratio of the second range to the first range of each door damper, which will be described later) is set so that when the door 30 is closed, the moment applied to the door 30 by the second door damper 70 is greater than the moment applied to the door 30 by the first door damper 60.

[0053] The balance of the loads (moment loads) applied to the door 30 by each door damper within the rotational range of the door 30 (the rotational range from the fully closed state to the fully open state) will be described below with reference to Fig. 7. The upper schematic diagram in Fig. 7 shows the balance of the loads applied to the door 30 by the first door damper 60, and the lower schematic diagram shows the balance of the loads applied to the door 30 by the second door damper 70. In addition, in each of the above schematic diagrams, the door 30 (each door hinge) viewed in the direction of the rotation axis of the door 30 is shown by a dashed line, and each door damper is shown by a thick line (solid line).

[0054] 7, an axis extending in the left-right direction indicates the locus of fulcrums C1 and C2 within the range in which the door 30 can rotate. In the illustrated example, fulcrum A is connected to fulcrums B1 and B2 by a dashed line X (see also FIGS. 5 and 6). Hereinafter, within the range in which the door 30 can rotate, the range on the opening side of the door 30 from line X (outside the cabin 10) will be referred to as a "first range," and the range on the closing side of the door 30 from line X (inside the cabin 10) will be referred to as a "second range."

[0055] Each door damper applies a moment to the door 30 in a direction to open the door 30 in a first range (when the fulcrums C1 and C2 are located in the first range), and applies a moment to the door 30 in a direction to close the door 30 in a second range (when the fulcrums C1 and C2 are located in the second range). That is, when the fulcrums C1 and C2 of each door damper cross the line X as the door 30 rotates, the direction of the force that each door damper applies to the door 30 changes. Note that when the fulcrums C1 and C2 are located on the line X, each door damper does not apply a force to the door 30 in a direction to close or open the door 30. In the following description, the state in which the fulcrums C1 and C2 are located on the line X will be referred to as the door damper being at its "dead center." The moment of each door damper increases as the fulcrums C1 and C2 move away from the line X.

[0056] 7 , the ratio of the second range to the first range of the second door damper 70 is configured to be greater than the ratio of the second range to the first range of the first door damper 60. In this embodiment, by setting the load balance of each door damper as described above, the moment with which the second door damper 70 closes the door 30 can be made greater than the moment with which the first door damper 60 closes the door 30.

[0057] In this manner, in this embodiment, by combining a means for providing a difference in the return force of each door damper with a means for providing a difference in the balance of the loads applied by each door damper to the door 30, the moment with which the second door damper 70 closes the door 30 is made greater than the moment with which the first door damper 60 closes the door 30 when the door 30 is closed. In this embodiment, the moment applied to the door 30 by the second door damper 70 when the door 30 is closed is configured to be approximately three times the moment applied to the door 30 by the first door damper 60 (see FIG. 7 ). Note that the moment values ​​of each door damper are not limited to the above-mentioned examples, and can be set to any appropriate value.

[0058] Furthermore, as shown in FIG. 7 , when the door 30 is in the fully closed state, the fulcrum C1 of the first door damper 60 is located near the line X (see also FIG. 5 ). In this embodiment, the angle by which the door 30 rotates from the state in which the fulcrum C1 is located on the line X until the door 30 is in the fully closed state is set to 5° or less. In this way, in this embodiment, the force with which the first door damper 60 presses the door 30 is relatively small, and the return force of the first door damper 60 hardly contributes to the closing direction of the door 30. On the other hand, as shown in FIG. 7 , the second door damper 70 applies a force to the door 30 in the closing direction when the first door damper 60 is at the dead point.

[0059] The tractor 1 according to this embodiment has the above-described configuration, which prevents the upper side of the door 30 (the part close to the second door damper 70) from opening unexpectedly and allows the door 30 to be opened and closed smoothly.

[0060] That is, since the door 30 provided in the cabin 10 of the tractor 1 is formed relatively large both vertically, if a door damper were provided only on the lower side of the door 30 (near the door handle 31 and handrail 32), the force holding down the upper side of the closed door 30 would be weak, and there is a risk that the upper side of the door 30 would suddenly open. Therefore, by providing door dampers (first door damper 60 and second door damper 70) at two locations, above and below, of the door 30 as in this embodiment, it is possible to hold down the top and bottom of the closed door 30, and it is possible to suitably prevent a portion of the door 30 (the upper side of the door 30 away from the door handle 31 and handrail 32) from opening.

[0061] 7, in this embodiment, when the door 30 is fully closed, the fulcrum C1 of the first door damper 60 is positioned near the line X, thereby making the force with which the first door damper 60 presses the door 30 relatively small. In this way, the upper and lower door dampers reliably press the door 30, while the force with which the lower first door damper 60 presses the door 30 is weakened, thereby preventing an increase in the operating load when opening the door 30 and suppressing a loss of operability of the door 30.

[0062] Furthermore, in this embodiment, when the door 30 is fully open, only the first door damper 60 is at its natural length, and the second door damper 70 is configured not to reach its natural length. If both door dampers were at their natural lengths when the door 30 was fully open, no force would be applied to the door 30 by the door dampers, which could cause rattles in the open state of the door 30. In this embodiment, even when the first door damper 60 is at its natural length, the second door damper 70 can apply a force to the door 30 in the opening direction, preventing rattles in the open state of the door 30.

[0063] As described above, the tractor 1 (work vehicle) according to this embodiment comprises: a cabin main body 10a; a door 30 rotatably mounted relative to the cabin main body 10a; a first door damper 60 mounted between the cabin main body 10a and the door 30; and a second door damper 70 disposed at a different position from the first door damper 60 in the direction along the rotation axis of the door 30 and mounted between the cabin main body 10a and the door, and is configured such that when the door 30 is closed, the moment applied by the second door damper 70 to the door 30 in the direction of closing the door 30 is greater than the moment applied by the first door damper 60 to the door 30 in the direction of closing the door 30. By configuring in this manner, a difference is created in the moments applied to the door 30 by the first door damper 60 and the second door damper 70 (the moment applied by the second door damper 70 is made greater than the moment applied by the first door damper 60), thereby preventing a part of the door 30 (the part close to the second door damper 70) from opening unexpectedly.

[0064] The second door damper 70 is disposed above the first door damper 60. This configuration makes it possible to prevent the upper side of the door 30 from opening unexpectedly.

[0065] The first door damper 60 and the second door damper 70 are configured to apply a moment to the door 30 in a direction to open the door 30 within a first range within the rotatable range of the door 30, and to apply a moment to the door 30 in a direction to close the door 30 within a second range within the rotatable range of the door 30, and the ratio of the second range to the first range of the second door damper 70 is greater than the ratio of the second range to the first range of the first door damper 60. By configuring in this way, the moment with which the second door damper 70 closes the door can be made greater than the moment with which the first door damper 60 closes the door.

[0066] Furthermore, the first door damper 60 and the second door damper 70 are configured to be extendable and retractable and to return to their natural lengths, and the return force of the second door damper 70 is configured to be greater than the return force of the first door damper 60. With this configuration, the moment with which the second door damper 70 closes the door can be made greater than the moment with which the first door damper 60 closes the door.

[0067] The tractor 1 further includes a door handle 31 provided on the door 30 and positioned closer to the first door damper 60 than the second door damper 70 in the direction along the rotation axis of the door 30. This configuration makes it possible to prevent the portion of the door 30 away from the door handle 31 from opening unexpectedly.

[0068] The tractor 1 further includes a handrail 32 (reinforcing member) provided on the door 30 and positioned closer to the first door damper 60 than the second door damper 70 in the direction along the rotation axis of the door 30. With this configuration, the portion of the door 30 away from the handrail 32 can be prevented from opening unexpectedly.

[0069] Furthermore, the first door damper 60 and the second door damper 70 are configured to be extendable and retractable and to return to their natural lengths, so that when the door 30 is fully open, only one of the first door damper 60 and the second door damper 70 is at its natural length. This configuration makes it possible to prevent the door 30 from rattling when it is open.

[0070] The tractor 1 according to this embodiment is one embodiment of a work vehicle according to the present invention. The handrail 32 according to this embodiment is one embodiment of a reinforcing member according to the present invention.

[0071] Although one embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0072] For example, in the tractor 1 according to the above embodiment, the moment with which the upper door damper (second door damper 70) closes the door 30 is greater than the moment with which the lower door damper (first door damper 60) closes the door 30, but the present invention is not limited to this. For example, the magnitude relationship between the moments of the upper and lower door dampers may be changed as desired depending on the configuration of the door 30.

[0073] In addition, in the above embodiment, an example was shown in which the moment at which the second door damper 70 closes the door 30 is made greater than the moment at which the first door damper 60 closes the door 30 by combining a means for creating a difference in the return force of each door damper with a means for creating a difference in the balance of the loads that each door damper applies to the door 30, but the present invention is not limited to this. For example, it is also possible to employ only one of the above means to make the moment at which the second door damper 70 closes the door 30 greater than the moment at which the first door damper 60 closes the door 30.

[0074] In the above embodiment, only the first door damper 60 has its natural length when the door 30 is fully open, but the present invention is not limited to this. For example, only the second door damper 70 may have its natural length when the door 30 is fully open. In the above embodiment, the first stay 41 and the second stay 51 have different extension lengths, so that only one of the door dampers has its natural length when the door 30 is fully open. However, the lengths of the door dampers may be different, so that only one of the door dampers has its natural length.

[0075] In addition, in the above embodiment, an example was shown in which the handrail 32 was used as the reinforcing member, but the reinforcing member is not limited to the handrail 32. For example, various members such as a frame provided on the door 30 can be used as the reinforcing member.

[0076] Furthermore, the shapes, structures, etc. of each part exemplified in the above embodiment are merely examples, and the configuration of each part can be changed as desired.

[0077] In the above embodiment, the tractor 1 is used as an example of the work vehicle, but the work vehicle is not limited to this. For example, the work vehicle may be an agricultural vehicle, a construction vehicle, an industrial vehicle, or the like.

[0078] The present invention can be applied to a work vehicle.

[0079] 1 Tractor 10a Cabin body 30 Door 60 First door damper 70 Second door damper

Claims

1. A work vehicle comprising a cabin main body, a door rotatably provided with respect to the cabin main body, a first door damper provided between the cabin main body and the door, and a second door damper provided between the cabin main body and the door and arranged at a position different from that of the first door damper in a direction along the rotation axis of the door, wherein in a state where the door is closed, a moment applied by the second door damper to the door in a direction of closing the door is configured to be larger than a moment applied by the first door damper to the door in a direction of closing the door.

2. The work vehicle according to claim 1, wherein the second door damper is arranged above the first door damper.

3. The first door damper and the second door damper apply a moment to the door in a direction of opening the door in a first range within a rotatable range of the door, and apply a moment to the door in a direction of closing the door in a second range within the rotatable range of the door, and a ratio of the second range to the first range of the second door damper is configured to be larger than a ratio of the second range to the first range of the first door damper. The work vehicle according to claim 1.

4. The first door damper and the second door damper are configured to be telescopic and return toward a natural length, and a restoring force of the second door damper is configured to be larger than a restoring force of the first door damper. The work vehicle according to claim 1.

5. The work vehicle according to claim 1, further comprising a door handle provided on the door and arranged closer to the first door damper than the second door damper in a direction along the rotation axis of the door.

6. The work vehicle according to claim 1, further comprising a reinforcing member provided on the door and arranged closer to the first door damper than the second door damper in a direction along the rotation axis of the door.

7. The first door damper and the second door damper are configured to be telescopic and return toward a natural length, and in a state where the door is fully opened, only one of the first door damper and the second door damper becomes a natural length. The work vehicle according to claim 1.

Images