Work vehicle

Abstract

To prevent soil and muddy water from entering a gear case accommodating a steering mechanism in the case where the gear case is provided below a floor of a driving section in a work vehicle.SOLUTION: A work vehicle includes: a steering mechanism 19 configured to steer wheels; and a gear case 18 accommodating the steering mechanism 19. The work vehicle further includes a first cover 31 attached from the gear case 18 to a lower surface part of a floor 26 and configured such that a periphery of a steering shaft 22, 23 between an opening 18a of the gear case 18 and an opening 26c of the floor 26, the opening 18a of the gear case 18, and the opening 26c of the floor 26 are covered so as to be shielded from a region below the floor 26.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a steering arrangement in a work vehicle. [Background technology]

[0002] In some work vehicles, as disclosed in Patent Document 1, a steering mechanism having a rack gear and a pinion gear is housed in a gear case, and the gear case is disposed below the floor of the driver's section.

[0003] In Patent Document 1, a steering shaft connected to a pinion gear passes through an opening at the top of the gear case and extends upward through an opening in the floor, and a steering handle is provided on the top of the steering shaft. The operator in the driving section operates the steering handle, rotates the steering shaft, and rotates the pinion gear, which causes the rack gear to move left and right and steers the front wheels (corresponding to the driving wheels).

[0004] In work vehicles that often travel on rough or muddy ground, if the gear case is located below the floor of the driver's section, dirt and muddy water are likely to adhere to the gear case. In this case, a disk-shaped cover is connected to the steering shaft near the opening of the gear case so as to rotate integrally with the steering shaft, and the outer periphery of the cover is disposed in contact with the outer periphery of the opening of the gear case, thereby covering the opening of the gear case, thereby preventing soil and muddy water from entering the inside of the gear case. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-11267 A (see 40 in Figs. 2 to 6) Summary of the Invention [Problem to be solved by the invention]

[0006] In a configuration in which the opening of the gear case is covered by a cover connected to the steering shaft, if the outer periphery of the cover is in contact with the outer periphery of the opening of the gear case, when the wheels are steered, the cover rotates together with the steering shaft, causing the outer periphery of the cover to rub against the outer periphery of the opening of the gear case. If this condition is repeated, wear will progress on the outer periphery of the cover and the outer periphery of the opening of the gear case, and there is a concern that a gap will appear between the outer periphery of the cover and the outer periphery of the opening of the gear case, which may allow dirt and muddy water to enter the inside of the gear case through this gap.

[0007] The present invention aims to provide a configuration in a work vehicle that can prevent soil or muddy water from entering the inside of a gear case that houses a steering mechanism when the gear case is located below the floor of the driver's section. [Means for solving the problem]

[0008] The work vehicle of the present invention is equipped with wheels for traveling, a steering mechanism for steer- ing the wheels, a gear case that houses the steering mechanism, a driving section provided above the gear case, a floor provided above the gear case and below the driving section, and a steering shaft that extends upward from the steering mechanism, through an opening in the upper part of the gear case and through an opening in the floor, and has a control handle provided at its upper part. The work vehicle is also equipped with a first cover that is attached across the gear case and the underside of the floor and covers the area around the steering shaft between the opening in the gear case and the opening in the floor, the opening in the gear case, and the opening in the floor so as to isolate the area below the floor.

[0009] According to the present invention, when the gear case that houses the steering mechanism is disposed below the floor of the driver's section, the first cover is attached across the gear case and the lower surface of the floor of the driver's section.

[0010] As a result, the area around the steering shaft between the opening of the gear case and the opening of the driver's section floor, as well as the opening of the gear case and the opening of the driver's section floor, are covered by the first cover and isolated from the area below the driver's section floor. Even when the wheels are steered, the first cover does not rotate, and there is no rubbing between the first cover and the underside of the gear case or the driver's floor, so there is little possibility of a gap occurring between the first cover and the underside of the gear case or the driver's floor.

[0011] Therefore, even if dirt or muddy water splatters around the gear case below the floor of the driver's section when the work vehicle is traveling on rough or muddy ground, the dirt or muddy water can adhere to the gear case and the outer surface of the first case, but cannot enter the inside of the first cover.

[0012] In this case, it seems possible for dirt and muddy water to enter the inside of the first cover from above the driver's section floor through the opening in the driver's section floor. However, because the floor of the driver's section is sufficiently wider than the opening of the floor of the driver's section above the first cover and the gear case, there is little possibility that dirt or muddy water flying around below the floor of the driver's section will cross the floor of the driver's section and reach the opening of the floor of the driver's section. In other words, the floor of the driver's section functions to prevent dirt or muddy water flying around below the floor of the driver's section from entering the opening of the floor of the driver's section.

[0013] As described above, by providing the first cover, which does not rotate even when the wheels are steered, while making effective use of the existing floor of the driver's section, it is possible to prevent soil and muddy water from entering the inside of the gear case, thereby improving the durability of the steering mechanism in the work vehicle.

[0014] In the present invention, it is preferable that a second cover is provided that covers the opening in the floor and a portion of the steering shaft above the opening in the floor.

[0015] Water, etc., from washing a work vehicle may end up on the upper surface of the floor of the driver's section. According to the present invention, the second cover covers the opening in the floor of the driver's section and covers the portion of the steering shaft above the opening in the floor of the driver's section. When the steering shaft extends upward through the opening in the upper part of the second cover, the opening in the second cover is located at a position higher than the upper surface of the floor of the driver's section.

[0016] This prevents water, etc., from entering the inside of the first cover through the opening in the floor of the driver's section when washing the work vehicle, which is advantageous in terms of improving the durability of the steering mechanism in the work vehicle. In this case, there is no need to set the gap between the steering shaft and the opening of the second cover smaller than necessary, so the steering shaft and the opening of the second cover are less likely to rub against each other, and wear is less likely to progress on the steering shaft and the opening of the second cover.

[0017] In the present invention, it is preferable that a lid portion is provided at a lower part of the first cover, has an opening through which the steering shaft passes, and closes the opening of the gear case inside the first cover.

[0018] Water, etc., from washing a work vehicle may end up on the upper surface of the floor of the driver's section. According to the present invention, at the lower part of the first cover, the opening of the gear case is covered by the lid portion, and the steering shaft extends upward through the opening of the lid portion.

[0019] This means that even if water or other liquids used when washing the work vehicle enter the inside of the first cover through the opening in the floor of the driver's section and reach the bottom of the first cover, the cover can prevent the water or other liquids from entering the inside of the gear case, which is advantageous in terms of improving the durability of the steering mechanism in the work vehicle. In this case, there is no need to set the gap between the steering shaft and the opening of the lid portion smaller than necessary, so the steering shaft and the opening of the lid portion are less likely to rub against each other, and wear is less likely to progress on the steering shaft and the opening of the lid portion.

[0020] In the present invention, it is preferable that a drainage path is provided that can drain water that has entered inside the first cover and reached a lower part of the first cover to the outside of the first cover.

[0021] According to the present invention, even if water or other liquids used when washing a work vehicle enter the inside of the first cover through an opening in the floor of the driver's section and reach the bottom of the first cover, the water or other liquids are discharged from the bottom of the first cover to the outside of the first cover through the drainage path. This is advantageous in that it prevents water, etc., from entering the inside of the gear case when the work vehicle is washed, and is advantageous in that it improves the durability of the steering mechanism in the work vehicle.

[0022] In the present invention, it is preferable that the lower portion of the first cover is inclined so that a portion of the drainage path in the lower portion of the first cover is lower than other portions of the lower portion of the first cover.

[0023] According to the present invention, water, etc., during washing of the work vehicle that reaches the lower part of the first cover is easily guided into the drainage path due to the inclination of the lower part of the first cover, facilitating the discharge of the water, etc. This is advantageous in that it prevents water, etc., from entering the inside of the gear case when the work vehicle is washed, and is advantageous in that it improves the durability of the steering mechanism in the work vehicle.

[0024] In the present invention, it is preferable that a vertical wall portion be provided that extends upward from the outer periphery of the opening of the lid portion along the outer periphery of the steering shaft and is provided around the entire outer periphery of the opening of the lid portion.

[0025] According to the present invention, even if water or the like when washing a work vehicle passes through the opening in the floor of the driver's section and enters the inside of the first cover and reaches the bottom of the first cover, the vertical wall portion of the lid prevents the water or the like from entering the opening of the lid. This is advantageous in that it prevents water, etc., from entering the inside of the gear case when the work vehicle is washed, and is advantageous in that it improves the durability of the steering mechanism in the work vehicle. [Brief description of the drawings]

[0026] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a vertical sectional left side view of the first cover, the second cover, the front panel, the steering mechanism, and the gear case. [Figure 4] FIG. 2 is a front view of the first cover, the front panel, the steering mechanism, and the gear case. [Diagram 5] FIG. 2 is a rear view of the first cover, the second cover, the front panel, the steering mechanism, and the gear case. [Figure 6] FIG. 2 is a vertical sectional left side view of the first cover, the second cover, the front panel, the steering mechanism, and the gear case. [Figure 7] FIG. 2 is a longitudinal sectional rear view of the first cover, the second cover, and the front panel. [Figure 8] FIG. 4 is a plan view of the first cover. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] A multipurpose work vehicle is shown in Figures 1 to 8, and in Figures 1 to 8, F indicates the forward direction, B indicates the rearward direction, U indicates the upward direction, D indicates the downward direction, R indicates the rightward direction, and L indicates the leftward direction.

[0028] (Overall configuration of the work vehicle) 1 and 2, right and left front wheels 1 (corresponding to wheels for driving) for driving are provided at the front of the machine body 3, and right and left rear wheels 2 for driving are provided at the rear of the machine body 3. The driver's section 4, in which an operator sits, is provided between the front wheels 1 and the rear wheels 2 of the machine body 3, and the driver's section 4 is surrounded by a ROPS frame 5. The driver's section 4 is provided with a driver's seat 6, a passenger seat 7, a floor 8, a steering wheel 9 for steering the front wheels 1, etc.

[0029] A bonnet 10 is provided in front of the driver's section 4, and a loading platform 11 is provided behind the driver's section 4. The loading platform 11 can be raised and lowered between a usage position shown by a solid line in Fig. 1 and a dump position in which the front part of the loading platform 11 is lifted up with the rear lower part of the loading platform 11 as a fulcrum.

[0030] An engine 12, a continuously variable transmission 13, and a transmission case 14 are provided at the rear of the machine body 3. The continuously variable transmission 13 is configured as a belt-type continuously variable transmission. An auxiliary transmission (not shown) capable of shifting to three forward speeds and one reverse speed, and a rear wheel differential (not shown) are provided inside the transmission case 14.

[0031] The power of the engine 12 is changed in speed by the continuously variable transmission 13, transmitted to the auxiliary transmission in the transmission case 14, further changed in speed, and transmitted from the rear wheel differential to the rear wheels 2. The power branched off between the auxiliary transmission and the rear wheel differential is transmitted to the front wheels 1 via a transmission shaft (not shown).

[0032] (Front wheel steering configuration) As shown in Figures 3, 4 and 5, right and left pipe-shaped frames 15 are provided along the front-to-rear direction at the lower part of the front of the fuselage 3, a pipe-shaped frame 16 is provided along the left-to-right direction at the lower part of the front of the fuselage 3, and a flat frame 17 is connected across frames 15, 16.

[0033] A gear case 18 is connected to the frame 17, and a steering mechanism 19 is housed inside the gear case 18. The steering mechanism 19 is of a rack and pinion type having a rack gear 20 and a pinion gear 21.

[0034] In the steering mechanism 19, the rack gear 20 is provided inside the gear case 18 so as to be movable in the left-right direction, and protrudes laterally outward from the right and left parts of the gear case 18. Right and left uprights (not shown) are provided to support the front wheels 1, and the rack gear 20 and the uprights are connected via tie rods (not shown).

[0035] 6, in the steering mechanism 19, the pinion gear 21 is rotatably provided inside the gear case 18 and meshes with the rack gear 20. The steering shaft 22 is connected to the pinion gear 21 and extends upward from the opening 18a of the gear case 18. A seal member 38 and a bearing 39 are provided in the opening 18a of the gear case 18.

[0036] As shown in Figures 3 to 6, the lower part of the steering shaft 23 is connected to the upper part of the steering shaft 22 via a universal joint 24, the upper part of the steering shaft 23 is connected to the operation handle 9, and an electric power steering mechanism 25 is provided on the steering shaft 23.

[0037] When an operator in the driver's seat 6 operates the steering wheel 9, the pinion gear 21 is rotated via the steering shafts 22, 23 and the power steering mechanism 25, and the rack gear 20 is moved left and right, thereby steering the front wheels 1.

[0038] (Configuration of front panel and second cover) As shown in FIGS. 3 to 6, a front panel 26 (corresponding to the floor 8) is connected to the front part of the floor 8 and forms a part of the front part of the floor 8. The front panel 26 is attached to the frame 16 and is disposed above the gear case 18.

[0039] The front panel 26 has a lower portion 26a connected to the front portion of the floor 8 and extending forward, and a front portion 26b extending upward from the front portion of the lower portion 26a, and is integrally molded from synthetic resin. An opening 26c is formed in the front panel 26 at the connection portion between the lower portion 26a and the front portion 26b.

[0040] The second cover 32 is attached to the upper surface of the connecting portion between the lower portion 26a and the front portion 26b of the front panel 26, and the opening 26c of the front panel 26 is covered from above by the second cover 32. The second cover 32 extends upward from the lower portion 26a of the front panel 26, and an opening 32a is formed in the upper portion of the second cover 32.

[0041] The steering shafts 22, 23 extend upward through an opening 26c in the front panel 26 and enter the interior of the second cover 32. The universal joint 24 is disposed inside the second cover 32. The steering shaft 23 extends upward through an opening 32a in the second cover 32, and the power steering mechanism 25 is disposed above the second cover 32.

[0042] (Correspondence to claims regarding the configuration of front wheel steering operation) With the above-mentioned configuration, the vehicle is equipped with wheels (front wheels 1) for driving, a steering mechanism 19 for steering the wheels (front wheels 1), a gear case 18 for housing the steering mechanism 19, a driver's section 4 provided above the gear case 18, and a floor 8 (front panel 26) provided above the gear case 18 and below the driver's section 4.

[0043] Steering shafts 22, 23 are provided which extend upward from the steering mechanism 19 through an opening 18a at the top of the gear case 18 and an opening 26c in the floor 8 (front panel 26) and have a steering handle 9 mounted on their upper portions.

[0044] A second cover 32 is provided which covers the opening 26c of the floor 8 (front panel 26) and the portion of the steering shafts 22, 23 above the opening 26c of the floor 8 (front panel 26).

[0045] (Configuration of the first cover) As shown in Figures 3 to 6, a first cover 31 is attached across the gear case 18 and the front panel 26. As shown in Figures 6, 7 and 8, the first cover 31 has a front portion 27, right and left side portions 28, a rear portion 29, a lower portion 30, etc., and is integrally molded from synthetic resin.

[0046] In the first cover 31, the lower part 30 has a rectangular shape in a plan view, and an opening 33 is provided in the center of the lower part 30. A vertical wall part 34 extending upward from the upper surface of the lower part 30 is provided around the entire outer periphery of the opening 33. A vertical wall part 35 extending downward from the lower surface of the lower part 30 is provided around the entire periphery slightly outside the outer periphery of the opening 33.

[0047] In the first cover 31, a drain hole 36 (corresponding to a drainage path) is opened in the rear left corner of the lower part 30, and the drain hole 36 is provided outside the opening 33 and the vertical wall portions 34, 35.

[0048] (First cover installed) As shown in Figures 3 to 7, the front portion 27, side portions 28 and rear portion 29 of the first cover 31 are attached to the lower surface of the lower portion 26a of the front panel 26 and the front surface of the front portion 26b, with a gasket 37 sandwiched between them.

[0049] As a result, the entire periphery of the opening 26c of the front panel 26 is covered from below by the front portion 27, the side portion 28 and the rear portion 29 of the first cover 31. The packing 37 is attached to the front panel 26 around the entire outer periphery of the opening 26c.

[0050] The lower portion 30 of the first cover 31 is pressed against the entire circumference of the outer periphery of the opening 18a of the gear case 18. The opening 18a of the gear case 18 fits inside the vertical wall portion 35 of the first cover 31, and the vertical wall portion 35 of the first cover 31 is in contact with the outer surface of the outer periphery of the opening 18a of the gear case 18 over the entire circumference.

[0051] The opening 18a of the gear case 18 is closed by the lower part 30 of the first cover 31. The opening 33 in the lower part 30 of the first cover 31 serves as a lid, and the opening 33 and a vertical wall part 34 are provided in the lid. The steering shaft 22 extends upward through the opening 33 of the first cover 31 (lid).

[0052] With the first cover 31 attached, the lower part 30 of the first cover 31 is inclined diagonally rearward and leftward, and the drain hole 36 is at the lowest position in the lower part 30 of the first cover 31. A drain hose 40 (corresponding to a drainage path) is connected to the drain hole 36.

[0053] As a result, the first cover 31 covers the opening 26c of the front panel 26 from below, covers and closes the opening 18a of the gear case 18 from above, and covers the periphery of the steering shafts 22, 23.

[0054] For example, suppose that water or the like seeps into the inside of the second cover 32 through the opening 32a of the second cover 32 when the work vehicle is washed. In this case, water, etc., enters the inside of the first cover 31 through the opening 26c of the front panel 26 along the inner surface of the second cover 32, and reaches the lower part 30 of the first cover 31 along the inner surfaces of the front part 27, side part 28 and rear part 29 of the first cover 31.

[0055] Water, etc. that reaches the lower part 30 of the first cover 31 flows along the slope of the lower part 30 of the first cover 31, reaches the drain hole 36 of the first cover 31, and is discharged from the drain hole 36 of the first cover 31 through the drain hose 40 to the outside of the first cover 31. Even if water, etc. flows near the opening 33 of the first cover 31, the vertical wall portion 34 of the first cover 31 prevents the water, etc. from entering the inside of the opening 33 of the first cover 31.

[0056] (Correspondence to claims in the first cover) With the above configuration, a first cover 31 is provided which is attached across the gear case 18 and the underside of the floor 8 (front panel 26) and covers the surroundings of the steering shafts 22, 23 between the opening 18a of the gear case 18 and the opening 26c of the floor 8 (front panel 26), as well as the opening 18a of the gear case 18 and the opening 26c of the floor 8 (front panel 26), isolating them from the area below the floor 8 (front panel 26).

[0057] A lid portion (lower portion 30) is provided at the lower portion 30 of the first cover 31 and has an opening 33 through which the steering shaft 22 passes, and closes the opening 18a of the gear case 18 inside the first cover 31.

[0058] A drainage path (drain hole 36 and drain hose 40) is provided to enable water that has entered inside first cover 31 and reached lower portion 30 of first cover 31 to be discharged to the outside of first cover 31.

[0059] The lower portion 30 of the first cover 31 is inclined so that a portion of the lower portion 30 of the first cover 31 where the drainage path (drain hole 36) is located is lower than other portions of the lower portion 30 of the first cover 31. A vertical wall portion 34 extends upward from the outer periphery of the opening 33 of the lid portion (lower portion 30) along the outer periphery of the steering shaft 22 and is provided around the entire outer periphery of the opening 33 of the lid portion (lower portion 30).

[0060] (First Alternative Embodiment of the Invention) The opening 33 in the lower portion 30 of the first cover 31 may be provided as a lid portion (not shown) made of a separate member. According to this configuration, the opening 33 and the vertical wall portion 34 are provided in the lid portion of the separate member, and the lid portion of the separate member is attached to the lower portion 30 of the first cover 31.

[0061] (Second Alternative Embodiment of the Invention) The portion (lid portion) of the opening 33 in the lower portion 30 of the first cover 31 may be eliminated. According to this configuration, the opening 18a of the gear case 18 is open toward the inside of the first cover 31, so the gap between the opening 32a of the second cover 32 and the steering shaft 23 can be set to be sufficiently small. Alternatively, the second cover 32 can be configured to be sufficiently high and extended to the vicinity of the steering handle 9.

[0062] (Third Alternative Embodiment of the Invention) Instead of the rack-and-pinion type steering mechanism 19, a pitman arm type steering mechanism 19 may be adopted.

[0063] (Fourth Alternative Embodiment of the Invention) The present invention may be adopted for the steering mechanism 19 of the rear wheels 2 in a configuration such that the rear wheels 2 are steered like a forklift, rather than the front wheels 1 being steered. [Industrial Applicability]

[0064] The present invention can be applied not only to work vehicles equipped with an engine, but also to electric work vehicles equipped with a motor for running, and hybrid work vehicles equipped with an engine and a motor for running. [Explanation of symbols]

[0065] 1 Front wheel (wheel) 4. Driving section 8th Floor 9. Steering Wheel 18 Gear case 18a opening 19 Steering mechanism 22 Steering shaft 23 Steering shaft 26 Front panel (floor) 26c opening 30 Lower part (lid) 31 First Cover 32 2nd Cover 33 Opening 34 Vertical wall section 36 Drain hole (drainage path) 40 Drain hose (drainage path)

Claims

1. Wheels for running; a steering mechanism for steering the wheels; a gear case that houses the steering mechanism; A driving unit provided above the gear case; A floor provided above the gear case and below the driving section; A steering shaft is provided, which extends upward from the steering mechanism through an opening in the upper part of the gear case and an opening in the floor, and has a steering handle provided at an upper part thereof. A work vehicle equipped with a first cover that is attached across the gear case and the underside of the floor and covers the area around the steering shaft between the opening of the gear case and the opening of the floor, as well as the opening of the gear case and the opening of the floor so as to isolate them from the area below the floor.

2. 2. The work vehicle according to claim 1, further comprising a second cover that covers the floor opening and a portion of the steering shaft that is above the floor opening.

3. 2. The work vehicle according to claim 1, further comprising a lid portion provided at a lower portion of the first cover, the lid portion having an opening through which the steering shaft passes and which closes the opening of the gear case from inside the first cover.

4. 4. The work vehicle according to claim 3, further comprising a drainage path capable of draining water that has entered inside the first cover and reached a lower portion of the first cover to the outside of the first cover.

5. 5. The work vehicle according to claim 4, wherein a lower portion of the first cover is inclined so that a portion of the drainage path at the lower portion of the first cover is lower than other portions at the lower portion of the first cover.

6. 4. A work vehicle as described in claim 3, further comprising a vertical wall portion extending upward from an outer periphery of the opening of the lid portion along an outer periphery of the steering shaft and extending around the entire outer periphery of the opening of the lid portion.

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