JP5566496B1 - Working vehicle traveling device - Google Patents

Abstract

To provide a traveling device for a work vehicle that is compatible with a single wheel, has a good straight-line stability of a vehicle, is less likely to cause uneven wear of wheels, and can reduce a load acting on a swing arm and a suspension bracket.
A traveling device 10 is such that a wheel W is steered by rotation of a rotating plate 50, and an axle 20 rotatably supports a wheel W which is a single wheel and is connected to a swing arm 30. Is done. The swing arm 30 extends rearward from the axle 30, and a tip end portion 30 a is attached to the lower end portion 40 a of the suspension bracket 40 so as to be rotatable around a horizontal axis O <b> 1. The upper end 40 b of the suspension bracket 40 is connected to the peripheral edge 50 a of the rotating plate 50 away from the rotation center K 1 of the rotating plate 50. The rotation center K1 of the rotation plate 50 is disposed in the vicinity of the vertical axis S1 extending in the vertical direction from the ground contact position of the wheel W when viewed from the left-right direction and the front-rear direction.
[Selection] Figure 3

Description

  The present invention relates to a traveling device for a work vehicle that steers a wheel that is a single wheel, and more particularly, to a traveling device for a work vehicle for traveling on a traveling road having a narrow width.

  For example, as described in Patent Document 1 below, the transport vehicle includes a traveling device that rotates each wheel at least on the front, rear, left, and right sides of the vehicle body. In this traveling device, as shown in FIG. 9, the axle 120 that rotatably supports the wheel W is connected to the swing arm 130, and the distal end portion 130 a of the swing arm 130 is rotatably attached to the lower end portion 140 a of the suspension bracket 140. It has been.

  The upper end portion 140b of the suspension bracket 140 is connected to the rotary plate 150, and the wheel W is steered by rotating the rotary plate 150 about the vertical axis E1. That is, when a steering motor (not shown) rotates the rotating plate 150 via the bearing 153, the suspension bracket 140, the swing arm 130, and the axle 120 are rotated so that the wheel W is steered independently of the other wheels. It has become.

JP 2002-108448 A

  By the way, the present applicant considers that the work vehicle travels on a traveling path provided between a certain base so that the load can be transported to an unspecified construction site. ing. However, the travel path is narrower than the work vehicle. Thus, it has been studied to apply a conventional traveling vehicle traveling device to a work vehicle on such a narrow travel road to cause the work vehicle to travel. However, there are the following problems.

  FIG. 10 (A) is a side view schematically showing the above-described conventional traveling device 110, and FIG. 10 (B) is a front view of FIG. 10 (A). In the conventional traveling device 110, as shown in FIG. 10 (B), a pair of wheels W, which are twin wheels, are attached to both ends in the left-right direction of the axle 120. As shown in FIG. From 120, the swing arm 130 extends in the forward direction (left side in FIG. 10A). The front end portion 130a of the swing arm 130 is attached to the lower end portion 140a of the suspension bracket 140 so as to be rotatable around the axis Q1 in the left-right direction. Further, a hydraulic cylinder 160 that can be expanded and contracted in the vertical direction is attached between the suspension bracket 140 and the swing arm 130 so that the vertical movement of the wheel W can be absorbed.

  When the traveling device 110 shown in FIG. 10 is used, since the structure is symmetrical with respect to the axle 120, each wheel W is indicated by an arrow even if the hydraulic cylinder 160 expands or contracts when traveling on an uneven road surface. It is difficult to tilt in the direction. And as shown in FIG.10 (B), four wheels W are arranged in the left-right direction in order to prevent the fall of the conveyance vehicle at the time of traversing. However, the length SN in the width direction from the leftmost wheel W to the rightmost wheel W (hereinafter referred to as “the left-to-right wheel length SN”) increases, and the road W is narrow when turning. The work vehicle may not be able to travel.

  On the other hand, FIG. 11 (A) is a side view schematically showing another traveling device 210, and FIG. 11 (B) is a front view of FIG. 11 (A). In this traveling device 210, as shown in FIG. 11B, one wheel W that is a single wheel is attached to one end of the axle 220 in the left-right direction, and the swing arm 230 extends in the left-right direction from the axle 220. ing. The front end portion 230a of the swing arm 230 is attached to the lower end portion 240a of the suspension bracket 240 so as to be rotatable about the longitudinal axis Q2. Further, a hydraulic cylinder 260 that can be expanded and contracted in the vertical direction is attached between the suspension bracket 240 and the swing arm 230 so that the vertical movement of the wheel W can be absorbed.

  When the traveling apparatus 210 shown in FIG. 11 is used, as shown in FIG. 11B, two wheels W are arranged in the left-right direction, and the length SN between the left and right wheels can be reduced. However, when the hydraulic cylinder 260 expands and contracts when traveling on an uneven road surface, the tip end portion 230a of the swing arm 230 rotates around the longitudinal axis Q2, and the wheels W tilt to the left and right as indicated by arrows. . As a result, a force is generated to bend the vehicle in the direction in which the wheels W are inclined, and the straight running stability of the vehicle is deteriorated. Furthermore, uneven wear tends to occur on the wheels W.

  In short, when the traveling device 110 corresponding to the twin wheels shown in FIG. 10 is used, the vehicle has good straight running stability, but the working vehicle has a large length SN between the left and right wheels. On the other hand, when the traveling device 210 corresponding to a single wheel shown in FIG. 11 is used, a working vehicle having a small left-to-right wheel length SN can be obtained, but the straight running stability of the vehicle is poor and uneven wear of the wheels tends to occur. When considering the structure of the traveling device, it is required to reduce the load acting on the swing arm and the suspension bracket as much as possible.

  Therefore, the present invention provides a traveling device for a work vehicle that is compatible with a single wheel, has a good straight-line stability of the vehicle, is less likely to cause uneven wear of wheels, and can reduce a load acting on a swing arm and a suspension bracket. The purpose is to provide.

In the traveling device for a work vehicle according to the present invention, an axle that rotatably supports a single wheel is connected to a swing arm, and the swing arm is rotatably attached to a lower end portion of a suspension bracket. The wheel is steered by rotating a rotating plate connected to the upper end about a vertical axis, and the swing arm extends forward or rearward from the axle, and its tip end is The suspension bracket is attached to the lower end portion of the suspension bracket so as to be rotatable about a horizontal axis, and the upper end portion of the suspension bracket is connected to the peripheral portion of the rotation plate away from the rotation center of the rotation plate. The rotation center of the rotating plate is in contact with the wheel when viewed from the left-right direction and the front-rear direction. From the position be located in the vicinity of the vertical axis or the vertical axis extending in the vertical direction, the suspension bracket and the swing arm is characterized in that it is arranged only on the vehicle inner side than the wheels during straight.

  According to the traveling device for a work vehicle according to the present invention, since the single wheel is supported by the axle, a work vehicle having a small length between the left and right wheels can be formed, which is sufficient for a narrow traveling road. It becomes a traveling device that can respond. And since the front-end | tip part of the swing arm extended in the front direction or the back direction rotates up and down around the axis line of the left-right direction, a wheel is hard to incline to the left and right. Therefore, the straight running stability of the vehicle is good and the uneven wear of the wheels hardly occurs. Further, since the rotation center of the rotating plate is arranged on or near the vertical axis extending in the vertical direction from the ground contact position of the wheel, when the wheel is steered, a bending moment generated in a member on the wheel side The bending moment generated by the member on the rotating plate side is canceled well, and the load acting on the swing arm and the suspension bracket can be reduced.

Further, in the traveling device for a work vehicle according to the present invention, the suspension bracket is attached with a reinforcing plate extending obliquely downward from the lower surface of the upper end portion extending in the horizontal direction, and the rotating plate is viewed from the left-right direction. It is preferable that a reinforcing rib extending obliquely downward is attached so as to overlap the reinforcing plate when viewed.
In this case, the reinforcing plate and the reinforcing rib can sufficiently withstand a bending moment generated when the upper end portion of the suspension bracket is separated from the rotation center of the rotating plate.

In the work vehicle traveling device according to the present invention, the swing arm includes a lower surface plate and an upper surface plate that extend in a horizontal direction, and includes a left side plate and a right side plate that stand up from both left and right ends of the lower surface plate, and When viewed from the front side of the direction, the bottom plate, the top plate, the left side plate, and the right side plate are preferably box-shaped.
In this case, the load acting on the wheel acts to twist the swing arm, but since the swing arm is box-shaped, the torsional rigidity is large and it can sufficiently withstand the twisting force.

Further, in the traveling device for a work vehicle according to the present invention, a bottom plate is attached to the bottom surface of the bottom plate of the swing arm, and the bottom plate is attached to a horizontal portion extending in a horizontal direction and a tip portion of the swing arm. Preferably, the upper surface plate has a horizontal portion extending in the horizontal direction and a curved portion extending obliquely upward toward the tip end portion of the swing arm.
In this case, the bottom arm, the top plate, the left side plate, and the right side plate also form the swing arm in a box shape, and the box-shaped section coefficient can be increased. Thereby, the torsional rigidity of the swing arm can be further increased.

In the traveling device for a work vehicle according to the present invention, it is preferable that a hydraulic cylinder that is extendable in the vertical direction is attached between the suspension bracket and the swing arm.
In this case, when traveling on a road surface with unevenness, the hydraulic cylinder expands and contracts so that the wheel follows the road surface unevenness to absorb the vertical movement of the wheel.

  According to the traveling device for a work vehicle of the present invention, it is compatible with a single wheel, the vehicle has good straight running stability, and uneven wear of wheels hardly occurs. Furthermore, the load acting on the swing arm and the suspension bracket can be reduced.

It is the figure which showed the work vehicle provided with the traveling apparatus of this embodiment. It is the side view which showed the traveling apparatus of this embodiment. FIG. 3 is a front view of FIG. 2. FIG. 3 is a plan view of FIG. 2. (A) It is the side view which showed the axle of FIG. FIG. 5B is a front view of FIG. (C) It is a top view of Drawing 5 (A). (A) It is the side view which showed the swing arm of FIG. (B) It is a front view of FIG. 6 (A). (C) It is a top view of FIG. 6 (A). (A) It is the side view which showed the suspension bracket of FIG. (B) It is a front view of FIG. 7 (A). (C) It is a top view of FIG. 7 (A). (A) It is the side view which showed the hydraulic cylinder of FIG. (B) It is a front view of FIG. 8 (A). (C) It is a top view of FIG. 8 (A). It is the side view which showed the traveling apparatus of the conventional conveyance vehicle. (A) It is the side view which showed the conventional traveling apparatus typically. (B) It is a front view of FIG. 10 (A). (A) It is the side view which showed another traveling apparatus typically. (B) It is a front view of FIG.

  An embodiment of a traveling device for a work vehicle according to the present invention will be described with reference to the drawings. FIG. 1 is a view showing a work vehicle 1 equipped with a traveling device 10 of the present embodiment, in which FIG. 1A shows a side view and FIG. 1B shows a plan view. In FIG. 1B, a part of the vehicle body 2 is shown through.

  The work vehicle 1 is a vehicle that travels on a narrow travel path SK provided between a certain base and transports a load to an unspecified construction site. As shown in FIGS. 1A and 1B, the work vehicle 1 rotates a vehicle body 2 on which a load can be placed, each wheel W that supports the vehicle body 2, and a part of each wheel W. A traveling motor 3 and a steering motor 4 that steers all the wheels W by hydraulic pressure are provided. The work vehicle 1 is capable of traveling such as turning, skewing, traversing, etc., by each steering motor 4 independently steering each wheel W.

  In this work vehicle 1, one traveling device 10 is provided for one wheel W that is a single wheel. Since the work vehicle 1 includes 16 wheels W, the work vehicle 1 includes a total of 16 traveling devices 10. In addition, the number of the wheels W and the traveling devices 10 included in the work vehicle 1 can be changed as appropriate. Since the configuration of each traveling device 10 is the same except for the front-rear direction and the presence or absence of the traveling motor 3, in the following, the traveling device 3 is disposed on the rearmost side (the right end in FIG. 1) of the vehicle body 10. One traveling device 10 provided will be described as a representative. 2 is a side view showing the traveling device 10, FIG. 3 is a front view of FIG. 2, and FIG. 4 is a plan view of FIG.

  As shown in FIGS. 2 to 4, the traveling device 10 mainly includes a traveling motor 3, an axle 20, a swing arm 30, a suspension bracket 40, a rotating plate 50, and a hydraulic cylinder 60. Has been. The traveling motor 3 rotates the wheels W, and is attached to the front side of the axle 20 (left side in FIG. 2). The traveling motor 3 is driven to rotate when a driving operator steps on an accelerator pedal, and the rotational driving force is transmitted to the wheels W via the axle 20. Here, FIG. 5 (A) is a side view of the axle 20 shown in FIG. 2, FIG. 5 (B) is a front view of FIG. 5 (A), and FIG. It is a top view of (A).

  The axle 20 rotatably supports the wheel W, and extends coaxially with the axle as shown in FIG. The axle 20 has a mounting portion 21 for mounting the wheel Wh of the wheel W on the vehicle outer side (right side in FIG. 3), and for mounting the swing arm 30 and the traveling motor 3 on the vehicle inner side (left side in FIG. 3). Main body 22. The attaching part 21 is arrange | positioned inside the wheel W, and is attaching the wheel Wh using each volt | bolt 23 at the four corners of the vehicle outer side part 21a. The main body 22 has a substantially rectangular parallelepiped shape and is disposed on the vehicle inner side than the wheels W. And the main-body part 22 has attached the motor 3 for driving | running | working by the front-surface part 22a, and has attached the swing arm 30 using the some volt | bolt 24 (refer FIG. 3) by the upper-surface part 22b. 6A is a side view of the swing arm 30 shown in FIG. 2, FIG. 6B is a front view of FIG. 6A, and FIG. It is a top view of 6 (A).

  The swing arm 30 swings with respect to the vertical movement of the wheel W and absorbs an impact. As shown in FIG. 3, the swing arm 30 is disposed on the vehicle inner side than the wheels W, and extends from the axle 20 toward the vehicle rear side (rear direction). And the front-end | tip part 30a of the swing arm 30 is attached with respect to the lower end part 40a of the suspension bracket 40 so that rotation is possible around the axis line O1 of the left-right direction using the rotating pin P1. Thus, the swing arm 30 can be rotated up and down around the axis O1 by the rotation pin P1. The detailed configuration of the swing arm 30 will be described later. 7A is a side view of the suspension bracket 40 shown in FIG. 2, FIG. 7B is a front view of FIG. 7A, and FIG. It is a top view of 7 (A).

  The suspension bracket 40 is a bracket for supporting the hydraulic cylinder 60. As shown in FIG. 3, the suspension bracket 40 is disposed on the inner side of the vehicle with respect to the wheels W. As shown in FIG. 7A, the suspension bracket 40 has an insertion hole 40a1 for the lower end portion 40a to pass through the rotation pin P1. doing. Further, as shown in FIG. 7C, the upper end portion 40b of the suspension bracket 40 extends in the horizontal direction and is integrally connected to the peripheral portion 50a of the rotating plate 50 away from the rotation center K1 of the rotating plate 50. doing.

  The rotating plate 50 is rotated around the rotation center K1 when a rotational force is transmitted from the steering motor 4. Due to the rotation of the rotating plate 50, the suspension bracket 40, the swing arm 30 and the axle 20 are rotated, and the wheel W is steered. The rotating plate 50 has a disk shape as shown in FIG. 7C, and a bearing 53 is assembled on the upper side as shown in FIG. Thereby, the rotation plate 50 is rotatable with respect to a vehicle body frame (not shown) via the bearing 53.

  External teeth (not shown) are formed on the outer ring 53a of the bearing 53, and the external teeth mesh with a pinion gear (not shown) that is rotated by the steering motor 4. Thus, the rotational force of the steering motor 4 is transmitted to the rotating plate 50 via the pinion gear and the outer ring 53a of the bearing 53. Detailed structures of the suspension bracket 40 and the rotating plate 50 will be described later.

  Here, FIG. 8 (A) is a side view of the hydraulic cylinder 60 shown in FIG. 2, FIG. 8 (B) is a front view of FIG. 8 (A), and FIG. It is a top view of 8 (A). As shown in FIG. 2, the hydraulic cylinder 60 is interposed between the suspension bracket 40 and the swing arm 30 and absorbs the vertical movement of the wheel W by expanding and contracting in the vertical direction. In the hydraulic cylinder 60, the cylinder rod 61 moves up and down with respect to the cylinder tube 62. And the front-end | tip part (lower end part) of the cylinder rod 61 is rotatably assembled | attached to the swing arm 30 via the support pin P2, and the base end part (upper end part) of the cylinder tube 62 is a suspension bracket via the support pin P3. 40 is rotatably assembled.

  The hydraulic cylinders 60 are provided one by one corresponding to the 16 wheels (see FIG. 1), and hydraulic oil flows between the hydraulic cylinders 60 through a common hydraulic pipe. For this reason, for example, when a certain wheel W rises due to the convex portion of the road surface, the hydraulic cylinder 60 corresponding to the wheel W contracts. As a result, the hydraulic oil in the hydraulic cylinder 60 flows into another hydraulic cylinder 60 through the hydraulic piping, and a damping force is generated by the flow of the hydraulic oil at this time, so that the rise of the wheel W is absorbed. Thus, when traveling on a road surface with unevenness, each hydraulic cylinder 60 expands and contracts, so that each wheel W follows the road surface unevenness and can absorb the vertical movement of each wheel W.

  By the way, the traveling device 10 of this embodiment has a structure that supports the wheel W that is a single wheel, and supports the wheel W that is a twin wheel like the conventional traveling device 110 shown in FIG. It is not structured. For this reason, by applying the traveling device 10 of the present embodiment to the work vehicle 1, the width direction from the leftmost wheel W to the rightmost wheel compared to the case where the conventional traveling device 110 is applied to the work vehicle 1. The length SN (length SN between the left and right wheels) can be reduced. As a result, the work vehicle 1 can be caused to travel without the wheels W coming off the travel path SK even on the narrow travel path SK. In addition, since the length SN between the left and right wheels is reduced, the size in the width direction of the body frame of the work vehicle 1 can be reduced.

  Further, as shown in FIG. 2, in the traveling device 10 of the present embodiment, the swing arm 30 extends in the rear direction, and the distal end portion 30 a of the swing arm 30 is in the left-right direction with respect to the lower end portion 40 a of the suspension bracket 40. It can be rotated around the axis O1. In other words, like the conventional traveling device 210 shown in FIG. 11B, the swing arm 230 extends in the left-right direction, and the front end portion 230a of the swing arm 230 is front and rear with respect to the lower end portion 240a of the suspension bracket 240. The structure is not rotatable around the direction axis Q2. For this reason, in this embodiment, when the hydraulic cylinder 60 expands and contracts when traveling on an uneven road surface, the suspension bracket 40 and the swing arm 30 rotate up and down around the axis O1, and the wheels W do not tilt left and right. Therefore, an unreasonable force for bending the vehicle does not act, the straight running stability of the vehicle is good, and uneven wear of the wheels W hardly occurs.

  Further, in the traveling device 10 of the present embodiment, the rotation center K1 of the rotation plate 50 is disposed on the vertical axis S1 extending in the vertical direction from the ground contact position of the wheel W when viewed from the left-right direction as shown in FIG. As shown in FIG. 3, when viewed from the front-rear direction, they are arranged in the vicinity of the vertical axis S1. For this reason, when the wheel W is steered, the bending moment generated by the member on the wheel W side and the bending moment generated by the member on the rotating plate 50 side are canceled well, and the load acts on the swing arm 30 and the suspension bracket 40. Has a small structure.

  In the traveling device 10 of the present embodiment, when viewed from the front-rear direction as shown in FIG. 3, the rotation center K1 of the rotation plate 50 is disposed slightly inside the vehicle from the vertical axis S1, and the rotation center K1. The distance t1 from the vertical axis S1 to about 25 mm. This is to minimize the amount of jumping out of the vehicle when the wheel W turns while satisfying the requirement to reduce the load acting on the swing arm 30 and the suspension bracket 40 as described above. Thus, the traveling device 10 of the present embodiment can sufficiently cope with the traveling path SK having a narrow width.

  Here, in the traveling apparatus 10 of this embodiment, as shown in FIG. 3, the swing arm 30 is arrange | positioned inside the vehicle from the wheel W, and it has the structure which supports the wheel W by cantilever. The swing arm 30 is configured to rotate up and down by the rotation pin P1 with respect to the suspension bracket 40. For this reason, the load which acts on the wheel W acts to twist the swing arm 30 around the rotation pin P1. Therefore, in this embodiment, in order to increase the torsional rigidity of the swing arm 30, the swing arm 30 is configured as follows.

  As shown in FIG. 6, the swing arm 30 includes a front end 30a through which the rotation pin P1 is inserted, a lower surface plate 30b and an upper surface plate 30c extending in the horizontal direction, a left side surface plate 30d and a right side plate standing from both left and right ends of the lower surface plate 30b. A face plate 30e is provided. As shown in FIG. 6A, the lower surface plate 30b extends in the horizontal direction. The upper surface plate 30c, as shown in FIG. 6 (A), faces the lower surface plate 30b and extends in the horizontal direction, and the horizontal portion 30c1. And a curved portion 30c2 extending obliquely upward toward the distal end portion 30a. 6B, when the swing arm 30 is viewed from the front side in the front-rear direction, the bottom plate 30b, the horizontal portion 30c1 of the top plate 30c, the left side plate 30d, and the right side plate 30e are used. It is box-shaped. As a result, the torsional rigidity of the swing arm 30 is enhanced by the box shape, and the swing arm 30 can sufficiently withstand the force acting to twist.

  In addition, as shown in FIG. 6A, the swing arm 30 has a bottom plate 30f attached to the lower surface of the lower plate 30b. The bottom plate 30f has a horizontal portion 30f1 extending in the horizontal direction and a curved portion 30f2 extending obliquely upward from the horizontal portion 30f1 toward the tip end portion 30a. The curved portion 30f2 of the bottom plate 30f and the curved portion 30c2 of the top plate 30c are substantially parallel. Thus, the bottom plate 30f is disposed further below the bottom plate 30b, so that the box-shaped section coefficient formed by the bottom plate 30f, the top plate 30c, the left side plate 30d, and the right side plate 30e is further increased. The torsional rigidity of the swing arm 30 can be further increased. An attachment portion 30g for attaching the tip of the cylinder rod 61 of the hydraulic cylinder 60 is provided at an intermediate position in the front-rear direction of the swing arm 30.

  In the traveling device 10 of the present embodiment, as shown in FIG. 3, the suspension bracket 40 is disposed away from the rotation center K1 of the rotation plate 50 toward the vehicle inner side. A relatively large bending moment acts on the rotating plates 50 that are integrally connected. Therefore, in this embodiment, the suspension bracket 40 and the rotating plate 50 are configured as follows in order to increase the rigidity against the bending moment.

  The suspension bracket 40 has a lower end portion 40a through which the rotation pin P1 is inserted as shown in FIG. 7 (A), and extends in the horizontal direction as shown in FIG. 7 (C) and is connected to the peripheral portion 50a of the rotation plate 50. The upper end portion 40b has a pair of side surface portions 40c that connect the upper end portion 40b and the lower end portion 40a as shown in FIG. 7 (B), and the upper end portion as shown in FIG. 7 (A). There is an inclined surface portion 40d extending obliquely between 40b and the lower end portion 40a. In the suspension bracket 40, two vertical plates 41 extending downward in the vertical direction are attached to the horizontal upper end portion 40b as shown in FIGS. 7A and 7C in order to increase the rigidity against the bending moment. It has been. Further, in order to increase the internal rigidity of the suspension bracket 40, a reinforcing plate 42 is attached that extends obliquely downward from the upper end 40b to the lower end 40a.

  In addition, in order to increase the rigidity with respect to the bending moment, two vertical ribs 51 extending downward in the vertical direction are also attached to the rotating plate 50 as shown in FIGS. In particular, in the present embodiment, as shown in FIG. 7A, the reinforcing rib 52 extending obliquely downward so as to overlap the above-described reinforcing plate 42 is attached to the rotating plate 50 when viewed from the left-right direction. There is a special feature. The applicant of the present application has described that the rigidity against the bending moment is greatly increased by extending the reinforcing rib 52 obliquely downward so as to overlap the reinforcing plate 42, for example, compared to the case of extending downward in the vertical direction. The result was confirmed.

  Thus, the vertical plate 41, the vertical rib 51, in particular, the reinforcing plate 42 and the reinforcing rib 52, can sufficiently withstand the bending moment generated when the suspension bracket 40 is separated from the rotation center K1 of the rotating plate 50 toward the vehicle inner side. As shown in FIG. 7C, an attachment portion 40e for attaching the base end portion of the cylinder tube 62 of the hydraulic cylinder 60 is provided between the vertical plate 41 and the reinforcing plate 42 of the suspension bracket 40. Yes.

The effect of the traveling apparatus 10 of this embodiment is demonstrated.
According to this embodiment, since the wheel W which is a single wheel is supported by the axle 20, the work vehicle 1 having a small length between the left and right wheels can be configured, and can sufficiently cope with the travel path SK having a narrow width. . And since the front-end | tip part 30a of the swing arm 30 rotates up and down around the axis line O1 of the left-right direction, the wheel W is hard to incline right and left. Therefore, the straight running stability of the vehicle is good, and the partial wear of the wheels W hardly occurs. Further, as shown in FIGS. 2 and 3, the rotation center K1 of the rotation plate 50 is disposed in the vicinity of the vertical axis S1 extending in the vertical direction from the ground contact position of the wheel W, so that the wheel W is steered. The bending moment generated by the member on the wheel W side and the bending moment generated by the member on the rotating plate 50 side are canceled well, and the load acting on the swing arm 30 and the suspension bracket 40 can be reduced.

As mentioned above, although embodiment of the traveling apparatus of the working vehicle which concerns on this invention was described, this invention is not limited to this embodiment, A various change is possible in the range which does not deviate from the meaning.
For example, in this embodiment, as shown in FIG. 3, when viewed from the front-rear direction, the rotation center K1 of the rotation plate 50 is disposed slightly on the vehicle inner side from the vertical axis S1, but is disposed on the vertical axis S1. Also good. That is, the rotation center K1 may be arranged on the vertical axis S1 in both the left-right direction and the front-rear direction. In this case, when the wheel W is steered, the bending moment generated by the member on the wheel W side and the bending moment generated by the member on the rotating plate 50 side can be most canceled and act on the swing arm 30 and the suspension bracket 40. Load can be minimized.

Further, in the work vehicle 1 of the present embodiment, since the wheels W are multi-axis like 16 axes, the hydraulic cylinder 60 is provided in the traveling device 10 so that each wheel W can follow the unevenness of the road surface. In the case of a work vehicle having four wheels, the traveling device may not be provided with a hydraulic cylinder.
In the present embodiment, the steering motor 4 that is operated by hydraulic pressure is used as a steering actuator that steers each wheel W. However, an electric motor may be used and can be changed as appropriate.
In addition, although the traveling apparatus 10 of this embodiment was applied to the work vehicle 1 which is manned, it can be applied also to an automatic guided vehicle.

DESCRIPTION OF SYMBOLS 1 Work vehicle 2 Car body 3 Driving motor 4 Steering motor 10 Traveling device 20 Axle 30 Swing arm 30a Tip part 30b Lower surface plate 30c Upper surface plate 30c1 Horizontal portion 30c2 Curved portion 30d Left side plate 30e Right side plate 30f Bottom plate 30f1 Horizontal portion 30f2 Curved Portion 40 Suspension bracket 40a Lower end 40b Upper end 41 Vertical plate 42 Reinforcement plate 50 Rotation plate 50a Peripheral portion 51 Vertical rib 52 Reinforcement rib K1 Rotation center S1 Vertical axis

Claims (5)

An axle that rotatably supports a single wheel is connected to the swing arm,
The swing arm is rotatably attached to the lower end of the suspension bracket,
In a traveling device for a work vehicle in which the wheel is steered by rotating a rotating plate connected to the upper end of the suspension bracket around a vertical axis,
The swing arm extends forward or rearward from the axle, and a tip portion of the swing arm is attached to a lower end portion of the suspension bracket so as to be rotatable around a horizontal axis.
The upper end of the suspension bracket is connected to the peripheral edge of the rotating plate away from the rotation center of the rotating plate,
The rotation center of the rotating plate is disposed on or near the vertical axis extending in the vertical direction from the ground contact position of the wheel when viewed from the left-right direction and the front-rear direction ,
The traveling device for a work vehicle, wherein the swing arm and the suspension bracket are arranged only on the vehicle inner side than the wheel when traveling straight . In the traveling apparatus for the work vehicle according to claim 1,
A reinforcing plate extending obliquely downward from the lower surface of the upper end portion extending in the horizontal direction is attached to the suspension bracket,
A traveling device for a work vehicle, wherein a reinforcing rib extending obliquely downward is attached to the rotating plate so as to overlap the reinforcing plate when viewed from the left-right direction. In the traveling apparatus for work vehicles according to claim 1 or 2,
The swing arm has a lower surface plate and an upper surface plate that extend in the horizontal direction, and also has a left side surface plate and a right side surface plate that stand up from the left and right ends of the lower surface plate, and the lower surface plate when viewed from the front side in the front-rear direction. And a top plate, the left side plate, and the right side plate are box-shaped. In the traveling apparatus for work vehicles according to claim 3,
A bottom plate is attached to the bottom surface of the bottom plate of the swing arm,
The bottom plate has a horizontal portion extending in the horizontal direction and a curved portion extending obliquely upward toward the tip portion of the swing arm,
The upper surface plate includes a horizontal portion extending in a horizontal direction and a curved portion extending obliquely upward toward a tip portion of the swing arm. In the traveling apparatus for work vehicles according to any one of claims 1 to 4,
A traveling apparatus for a work vehicle, wherein a hydraulic cylinder that is extendable in a vertical direction is attached between the suspension bracket and the swing arm.

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