Work vehicle

Abstract

To provide a working vehicle capable of properly sealing between a cylindrical part and an input shaft.SOLUTION: A tractor 1 includes a power steering controller 24 having an input shaft 24b directed upward, a support member 25 having a cylindrical part 25c into which the input shaft 24b is inserted from below and supporting the power steering controller 24, and a seal member 40 closing a gap between the cylindrical part 25c and the input shaft 24b, wherein the seal member 40 includes a contact part 41 disposed so as to come into contact with an outer peripheral surface of the input shaft 24b and a fixing part 42 formed of a material having hardness higher than that of the contact part 41 and fixing the contact part 41 to the support member 25.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, technology for a work vehicle equipped with a power steering controller for assisting the steering force of an operator has been publicly known, as described in Patent Document 1, for example.

[0003] Patent Document 1 describes a tractor equipped with a steering wheel, a power steering controller that controls the extension and retraction of a power steering cylinder, and a steering shaft that connects the steering wheel and the power steering controller. The power steering controller is supported by a support member (power steering holder).

[0004] In such a tractor, the input shaft (switching shaft) of the power steering controller is inserted through a cylindrical portion of the support member. The input shaft is rotatably supported in the cylindrical portion by a bearing disposed inside the cylindrical portion. When the steering wheel is operated, the input shaft (switching shaft) is rotated via the steering shaft. The rotation of the input shaft switches the oil passages in the power steering controller, thereby controlling the extension and retraction of the power steering cylinder. The front wheels are steered left and right in response to the extension and retraction of the power steering cylinder.

[0005] In such tractors, water may seep into the power steering controller, causing rust on components inside the controller, such as bearings. For this reason, there is a demand for a work vehicle that can properly seal the gap between the cylindrical portion of the support member and the input shaft of the power steering controller. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-331638 Summary of the Invention [Problem to be solved by the invention]

[0007] 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 properly seal the space between the cylindrical portion and the input shaft. [Means for solving the problem]

[0008] 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.

[0009] A work vehicle according to one aspect of the present disclosure comprises a power steering controller having an input shaft facing upward, a support member having a cylindrical portion through which the input shaft is inserted from below and supporting the power steering controller, and a sealing member that seals the gap between the cylindrical portion and the input shaft, the sealing member comprising a contact portion that is arranged to contact the outer peripheral surface of the input shaft, and a fixing portion that is formed from a material having a higher hardness than the contact portion and that fixes the contact portion to the support member. According to one aspect of the present disclosure, the gap between the cylindrical portion and the input shaft can be appropriately sealed.

[0010] The contact portion according to one aspect of the present disclosure is formed to come into contact with a plurality of portions of the input shaft in the axial direction. According to one aspect of the present disclosure, the contact portion is brought into contact with a plurality of portions of the input shaft, thereby improving sealing performance.

[0011] In one embodiment of the present disclosure, the contact portion includes a first contact portion formed in a flat plate perpendicular to the input shaft and contacting a first portion of the input shaft, and a second contact portion formed below the first contact portion and contacting a second portion of the input shaft. According to one aspect of the present disclosure, the first contact portion formed in a flat plate shape can prevent water from accumulating on the second contact portion.

[0012] In one embodiment of the present disclosure, the input shaft has a reduced diameter portion having a smaller diameter than the portions on both sides in the axial direction, and at least one of the first contact portion and the second contact portion is formed to contact the reduced diameter portion. According to one aspect of the present disclosure, by bringing the contact portion into contact with the reduced diameter portion, it is possible to prevent the seal member from moving (falling off from the input shaft).

[0013] The fixing portion according to one aspect of the present disclosure is fitted to the outside of the cylindrical portion. According to one aspect of the present disclosure, the fixing portion can be easily fixed to the tubular portion. Furthermore, by covering the tubular portion with the fixing portion, it is possible to prevent water from entering the inside of the tubular portion.

[0014] The fixing portion according to one aspect of the present disclosure is fitted inside the cylindrical portion. According to one aspect of the present disclosure, the fixing portion can be easily fixed to the tubular portion.

[0015] A work vehicle according to one aspect of the present disclosure further includes a covering member that covers the cylindrical portion from above. According to one aspect of the present disclosure, it is possible to prevent water from entering the inside of the cylindrical portion.

[0016] The covering member according to one aspect of the present disclosure is formed in a flat plate shape and is arranged so as to be inclined relative to the horizontal direction, and the covering member has a protrusion formed at the lower end in the inclined direction of the covering member that protrudes radially in the tubular portion. According to one aspect of the present disclosure, water adhering to the covering member can be collected and dropped onto the protrusion away from the cylindrical portion, thereby preventing water from penetrating into the cylindrical portion.

[0017] In one aspect of the present disclosure, at least one of the sealing member and the cylindrical portion is formed with a drainage portion for draining water from the inside to the outside of the cylindrical portion. According to one aspect of the present disclosure, water that has entered the inside of the cylindrical portion can be discharged. [Effects of the Invention]

[0018] According to one aspect of the present disclosure, the gap between the cylindrical portion and the input shaft can be appropriately sealed. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a side view showing the overall configuration of a tractor according to a first embodiment of the present disclosure; [Figure 2] A cross-sectional plan view showing the interior of the cabin. [Figure 3] FIG. 2 is a side view showing the interior of the cabin and the steering device. [Figure 4] FIG. 2 is a perspective view showing a power steering controller attached to a bracket. [Figure 5] FIG. [Figure 6] FIG. 3 is a right side cross-sectional view showing the power steering controller. [Figure 7] FIG. 6 is a perspective view showing a power steering controller according to a second embodiment. [Figure 8] FIG. 6 is a right side cross-sectional view showing a power steering controller according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] 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.

[0021] First, the overall configuration of a tractor 1 according to an embodiment of the present disclosure will be described.

[0022] The tractor 1 shown in Figure 1 mainly comprises a body frame 2, an engine 3, a hood 4, a transmission case 5, a hood support 6, front wheels 7, rear wheels 8, fenders 9, a lifting device 10, a cabin 11, seats 12, a right console 13, a left console 14, and a steering device 20.

[0023] The body frame 2 is a frame-like member formed by appropriately combining multiple plate materials. The body frame 2 is formed in a generally rectangular shape when viewed from above. The 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 body frame 2. The engine 3 is covered by a bonnet 4. A transmission case 5 is fixed to the rear of the engine 3. A bonnet support part 6 is disposed behind the engine 3 and at the upper front of the transmission case 5 (see Figure 3). The bonnet support part 6 is formed of a columnar member or the like and is fixed to the upper front of the transmission case 5. The bonnet 4 is supported by the bonnet support part 6 so as to be rotatable up and down. A muffler 4a that discharges exhaust gas from the engine 3 is disposed on the right side of the bonnet 4.

[0024] The front of the vehicle frame 2 is supported by a pair of left and right front wheels 7 via a front axle mechanism (not shown). The rear of the transmission case 5 is supported by a pair of left and right rear wheels 8 via a rear axle mechanism (not shown). The pair of left and right rear wheels 8 are generally covered from above by fenders 9.

[0025] A lifting device 10 is provided at the rear of the transmission case 5. Various types of working equipment (for example, a tiller) can be attached to the lifting device 10. The lifting device 10 can raise and lower the attached working equipment using an actuator such as a hydraulic cylinder. Power from the engine 3 can be transmitted to the working equipment attached to the lifting device 10 via a PTO shaft (not shown).

[0026] The power of the engine 3 is changed in speed by a transmission (not shown) housed in the transmission case 5, and then can be transmitted to the front wheels 7 via the front axle mechanism, and can be transmitted to the rear wheels 8 via the rear axle mechanism. The front wheels 7 and rear wheels 8 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 working device attached to the lifting device 10.

[0027] A cabin 11 is provided behind the engine 3. The cabin 11 is mounted on the vehicle body (transmission case 5, etc.). A living space for a driver is formed inside the cabin 11. As shown in FIG. 1, a seat 12 for the driver to sit on is disposed approximately in the center of the cabin 11. A partition plate 11a is provided in the front of the cabin 11 to separate the interior space of the cabin 11 from the interior space of the hood 4 (see FIG. 2).

[0028] 2, a right console 13 and a left console 14 are provided inside the cabin 11. Various operating tools are appropriately arranged on the right console 13. The left console 14 is formed so as to be able to store appropriate items.

[0029] A steering device 20 for adjusting the turning angle of the front wheels 7 is disposed in front of the cabin 11. The steering device 20 for adjusting the turning angle of the front wheels 7 will be described below with reference to Figs. 2 to 6.

[0030] The steering device 20 mainly includes a steering wheel 21, a first steering shaft 22, a second steering shaft 23, a power steering controller 24, a support member 25, and a seal member 40.

[0031] The steering wheel 21 is an operating tool used by the driver to steer the front wheels 7. The steering wheel 21 is disposed in front of the seat 12.

[0032] 3 is a shaft-shaped member that rotates in response to the rotation of the steering wheel 21. The upper end of the first steering shaft 22 is fixed to the center of the steering wheel 21. The first steering shaft 22 is disposed so as to extend downward and forward from the steering wheel 21.

[0033] The second steering shaft 23 shown in FIG. 3 is a shaft-shaped member that rotates in response to the rotation of the steering wheel 21. The upper end of the second steering shaft 23 is connected to the lower end of the first steering shaft 22 via a universal joint (not shown). The second steering shaft 23 is arranged to extend downward and forward from the first steering shaft 22. The second steering shaft 23 is arranged so that its inclination angle (angle of inclination with respect to the vertical direction) is larger than that of the first steering shaft 22 in a side view. The second steering shaft 23 is arranged to pass through the partition plate 11a of the cabin 11. As a result, the lower end of the second steering shaft 23 is arranged inside the hood 4.

[0034] The power steering controller 24 controls the operation of the actuator 7a (see FIG. 1) that operates the front wheels 7. The power steering controller 24 is a control valve that can switch oil passages through which hydraulic oil flows. The power steering controller 24 can control the operation of the actuator 7a (specifically, an extendable hydraulic cylinder) that changes the turning angle of the front wheels 7 by switching the oil passage that supplies hydraulic oil from a hydraulic pump (not shown) to the actuator 7a. The power steering controller 24 is disposed in front of the partition plate 11a of the cabin 11 (inside the hood 4). The power steering controller 24 (more specifically, an input shaft 24b, which will be described later) is connected to the lower end of the second steering shaft 23 via a universal joint 23a.

[0035] The power steering controller 24 mainly includes a case 24a and an input shaft 24b.

[0036] The case 24a shown in Figures 4 and 5 is a box-shaped member that houses oil passages for hydraulic oil, control valves that switch the oil passages, and the like. The case 24a is formed in a substantially rectangular parallelepiped shape. The case 24a is disposed with its longitudinal direction oriented substantially in the vertical direction. A boss portion 24d is formed in the approximate center of the top surface 24c of the case 24a. The boss portion 24d is formed so as to protrude upward from the top surface 24c. The outer shape of the boss portion 24d (the outer shape of the case 24a as viewed in the longitudinal direction) is formed in a circular shape. A stud bolt 28 is fixed to the top surface 24c of the case 24a.

[0037] 4 to 6 is a switching shaft that operates a control valve in the case 24a and switches the oil passage. The input shaft 24b is disposed so as to penetrate the upper surface 24c of the case 24a (more specifically, the center of the boss portion 24d). The input shaft 24b is disposed so that its upper portion protrudes upward from the upper surface 24c of the case 24a.

[0038] As shown in FIG. 6, the input shaft 24b has a large-diameter portion 24e that constitutes a portion extending from the middle to the lower portion in the axial direction of the input shaft 24b (hereinafter, sometimes simply referred to as the "axial direction"). Retaining rings 24h are provided on the large-diameter portion 24e at positions above and below a ball bearing 33, which will be described later. The large-diameter portion 24e is formed to have a constant diameter except for the portion where the retaining rings 24h are provided. The input shaft 24b also has a splined connecting portion 24f above the large-diameter portion 24e. The connecting portion 24f is connected to the universal joint 23a (see FIG. 3). The input shaft 24b also has a reduced-diameter portion 24g between the connecting portion 24f and the large-diameter portion 24e. The reduced-diameter portion 24g is formed adjacent to the large-diameter portion 24e and the connecting portion 24f, and has a smaller diameter than the connecting portion 24f and the large-diameter portion 24e. The upper end of the reduced diameter portion 24g is tapered so that the diameter gradually increases toward the upper side in the axial direction, and the lower end of the reduced diameter portion 24g is tapered so that the diameter gradually increases toward the lower side in the axial direction.

[0039] The support member 25 is a member that supports the power steering controller 24. The support member 25 is provided at the bottom of the bonnet support portion 6. The power steering controller 24 is fixed to the bottom of the support member 25. The support member 25 mainly includes a first plate portion 25a, a second plate portion 25b, a cylindrical portion 25c, and a rib 25d.

[0040] 4 and 5 is a portion that is fixed to the bonnet support portion 6. The first plate portion 25a is formed in a substantially rectangular plate shape. The first plate portion 25a is disposed with its plate surface facing in the front-rear direction.

[0041] The second plate portion 25b shown in FIG. 5 is a portion that supports the power steering controller 24. The second plate portion 25b is formed in a substantially rectangular plate shape. The second plate portion 25b is disposed with its plate surface facing substantially in the vertical direction. The second plate portion 25b is formed to extend rearward and downward from the lower end of the first plate portion 25a. More specifically, the second plate portion 25b is formed to be slightly inclined rearward and downward (slightly (approximately 20 degrees) with respect to the horizontal direction) from the lower end of the first plate portion 25a. The second plate portion 25b has through holes 25e that pass through the second plate portion 25b in the vertical direction. The through holes 25e are formed in multiple locations (in this embodiment, four locations around a tubular portion 25c, which will be described later).

[0042] The cylindrical portion 25c shown in Figures 4 to 6 is a portion through which the input shaft 24b is inserted. The boss portion 24d of the power steering controller 24 is inserted into the lower portion of the cylindrical portion 25c. The cylindrical portion 25c is formed in a cylindrical shape with an inner diameter substantially equal to the outer diameter of the boss portion 24d. The cylindrical portion 25c is disposed so as to vertically penetrate substantially the center of the second plate portion 25b. The lower end portion of the cylindrical portion 25c is disposed so as to protrude slightly downward from the second plate portion 25b.

[0043] A ball bearing 33 is disposed inside the cylindrical portion 25c. The input shaft 24b is rotatably supported by the cylindrical portion 25c via the ball bearing 33. A retaining ring 34 is provided on the cylindrical portion 25c above the ball bearing 33. The retaining ring 34 prevents the ball bearing 33 from falling out of the cylindrical portion 25c.

[0044] A drain groove 25f is formed at the upper end of the cylindrical portion 25c. The drain groove 25f is for draining water that has seeped into the inside of the cylindrical portion 25c to the outside. The drain groove 25f is formed in a roughly U-shape with the upper end of the cylindrical portion 25c cut out. The drain groove 25f is provided at the rear end of the upper part of the cylindrical portion 25c.

[0045] 5 reinforces the connecting portion between the first plate portion 25a and the second plate portion 25b. The rib 25d is formed in a generally plate-like shape with the plate surface facing in the left-right direction. The rib 25d is formed so as to connect both left and right ends of the first plate portion 25a and the second plate portion 25b.

[0046] The first plate portion 25a of the support member 25 is fixed to the bonnet support portion 6 by a bolt or the like. In this way, the support member 25 is attached to the bonnet support portion 6.

[0047] The stud bolt 28 provided on the power steering controller 24 is inserted from below the support member 25 through the through-hole 25e and cushion 29. The cushion 29 is made of a material that absorbs vibrations. The stud bolt 28 is further inserted through a washer 30. A nut 31 is fastened to the stud bolt 28 from above the washer 30. In this way, the power steering controller 24 is fixed to the support member 25.

[0048] The steering device 20 configured in this manner can adjust (steer) the turning angle of the front wheels 7. Specifically, when the steering wheel 21 is turned, the input shaft 24b of the power steering controller 24 turns via the first steering shaft 22 and the second steering shaft 23. As the input shaft 24b turns, the oil passage of the power steering controller 24 is switched appropriately, and hydraulic oil is supplied to the actuator 7a appropriately. This causes the actuator 7a to expand and contract, allowing the turning angle of the front wheels 7 to be adjusted.

[0049] If water seeps into the power steering controller 24, the ball bearings 33 and other components disposed inside the power steering controller 24 may rust. Therefore, a seal member 40 is provided on the top of the power steering controller 24 to prevent water from seeping into the power steering controller 24.

[0050] The seal member 40 shown in Figures 4 to 6 is a member for sealing the gap between the cylindrical portion 25c and the input shaft 24b. The seal member 40 is formed in a substantially bottomed cylindrical shape with the bottom surface facing substantially upward. The seal member 40 is provided so as to cover the cylindrical portion 25c from above. The seal member 40 includes a contact portion 41 and a fixing portion 42.

[0051] The contact portion 41 is a portion arranged to contact the outer peripheral surface of the input shaft 24b. The contact portion 41 is formed of a material having a relatively low hardness. The contact portion 41 is also formed of a material having elasticity. The contact portion 41 is also formed of a material having flexibility. The contact portion 41 is formed of, for example, soft rubber. The contact portion 41 includes a first contact portion 41a and a second contact portion 41b.

[0052] The first contact portion 41a shown in Fig. 6 is formed in a flat plate shape perpendicular to the input shaft 24b. The outer shape of the first contact portion 41a is formed in a circular shape when viewed in the axial direction. The first contact portion 41a is provided so that the center of the circle coincides with the axis of the input shaft 24b. A through hole 41c is formed in the first contact portion 41a.

[0053] The through hole 41c is formed in the center of the first contact portion 41a as viewed in the axial direction. The through hole 41c is formed in a circular shape as viewed in the axial direction. The reduced diameter portion 24g of the input shaft 24b is inserted into the through hole 41c. The through hole 41c is formed to have an inner diameter that is approximately the same as the outer diameter of the reduced diameter portion 24g of the input shaft 24b. More specifically, the through hole 41c is formed to have an inner diameter that is slightly smaller than the outer diameter of the reduced diameter portion 24g.

[0054] The first contact portion 41a formed in this manner is provided so as to come into contact with the reduced diameter portion 24g of the input shaft 24b at the end on the inner circumferential side.

[0055] The second contact portion 41b shown in FIG. 6 is formed below the first contact portion 41a. The second contact portion 41b is formed so as to extend obliquely downward from a radially intermediate portion of the lower surface of the first contact portion 41a toward the input shaft 24b. The second contact portion 41b is formed around the entire circumference of the first contact portion 41a. Thus, the second contact portion 41b is formed in the shape of a truncated cone whose diameter decreases toward the lower side in the axial direction. The inner diameter at the lower end of the second contact portion 41b is formed to be approximately the same as the outer diameter of the large diameter portion 24e of the input shaft 24b, and more specifically, is formed to be slightly smaller than the outer diameter of the large diameter portion 24e.

[0056] The second contact portion 41b formed in this manner is provided so as to come into contact with the large diameter portion 24e of the input shaft 24b at its lower end. In this way, the second contact portion 41b is provided so as to come into contact with the input shaft 24b below the first contact portion 41a.

[0057] The fixing portion 42 is a portion that fixes the contact portion 41 to the support member 25. The fixing portion 42 is provided so as to fit onto the outside of the cylindrical portion 25c. The fixing portion 42 is formed from a material that has a higher hardness than the contact portion 41, such as hard rubber or engineering plastic. The fixing portion 42 is formed integrally with the contact portion 41, for example, by two-color molding. The fixing portion 42 has an upper surface portion 42a and a side surface portion 42b.

[0058] The upper surface portion 42a constitutes the upper portion of the fixed portion 42. The outer shape of the upper surface portion 42a is formed in a substantially circular shape when viewed in the axial direction. The upper surface portion 42a is provided so that the center of the circle coincides with the axis of the input shaft 24b. A through hole 42c and a recess 42d are formed in the upper surface portion 42a.

[0059] The through hole 42c is formed in the center of the upper surface portion 42a when viewed in the axial direction. The through hole 42c is formed in a circular shape when viewed in the axial direction. The through hole 42c is formed so that its diameter decreases toward the lower side in the axial direction. The second contact portion 41b abuts against the inner circumferential surface of the through hole 42c.

[0060] The recess 42d is formed so that the upper surface portion 42a is recessed. The recess 42d is formed from the inner peripheral end portion of the upper surface portion 42a to the radially middle portion. The recess 42d is formed along the entire circumference of the through hole 42c. Thus, the recess 42d is formed in an annular shape when viewed in the axial direction. The recess 42d is formed to have an outer diameter that is approximately the same as the outer diameter of the first contact portion 41a. The recess 42d is formed to have a depth that is approximately the same as the thickness of the first contact portion 41a. The first contact portion 41a abuts against the recess 42d.

[0061] The side surface portion 42b is a portion that constitutes the side of the fixing portion 42. The side surface portion 42b is formed to extend downward in the axial direction from the outer peripheral end of the upper surface portion 42a. The side surface portion 42b is provided so that its inner peripheral surface is in contact with the outer peripheral surface of the cylindrical portion 25c.

[0062] A groove 42f is formed on the inner circumferential surface of the side surface portion 42b (see FIG. 6). The groove 42f is formed to extend in the axial direction. The upper end of the groove 42f is formed to communicate with the drain groove 25f. The lower end of the groove 42f is formed to extend to the lower end of the side surface portion 42b and is open. If water seeps inside the cylindrical portion 25c, the water can be discharged to the outside of the cylindrical portion 25c via the drain groove 25f and the groove 42f.

[0063] The seal member 40 formed in this manner can be fixed to the cylindrical portion 25c (support member 25) with the contact portion 41 in contact with the input shaft 24b by fitting the fixing portion 42 to the outside of the cylindrical portion 25c. In this way, by bringing the relatively soft contact portion 41 into contact with the input shaft 24b, it is possible to seal between the cylindrical portion 25c and the input shaft 24b. Furthermore, because the relatively soft contact portion 41 is brought into contact with the input shaft 24b, an increase in the operating force of the steering wheel 21 can be suppressed.

[0064] Furthermore, by fitting the relatively hard fixing portion 42 into the cylindrical portion 25c, the contact portion 41 can be firmly fixed. This improves the sealing performance. Furthermore, since the fixing portion 42 is made of a relatively hard material, the assembly of the seal member 40 can be improved.

[0065] Furthermore, the contact portion 41 is formed so as to contact two locations in the axial direction, namely, the first contact portion 41a and the second contact portion 41b. By sealing the gap between the cylindrical portion 25c and the input shaft 24b at multiple locations in this manner, it is possible to further improve the sealing performance. Furthermore, by having the contact portion 41 contact the input shaft 24b at multiple locations, it is possible to reduce the pressing force at one contact location. This allows the steering force of the steering wheel 21 to be reduced.

[0066] Furthermore, both upper and lower ends of the reduced-diameter portion 24g are tapered so that the diameter gradually increases. Therefore, if the relative vertical position of the contact portion 41 with respect to the input shaft 24b is shifted due to dimensional errors or backlash of the parts, the way in which the contact portion 41 contacts the reduced-diameter portion 24g will change. For this reason, it is difficult to achieve stable sealing by simply having the contact portion 41 contact the reduced-diameter portion 24g. On the other hand, in this embodiment, the second contact portion 41b contacts the large-diameter portion 24e, which has a constant diameter. Therefore, even if the relative vertical position of the contact portion 41 with respect to the input shaft 24b is shifted slightly, the second contact portion 41b can be stably contacted with the input shaft 24b.

[0067] However, because the second contact portion 41b extends diagonally downward toward the input shaft 24b, water is likely to accumulate on the surface of the second contact portion 41b if only the second contact portion 41b is present. Therefore, the first contact portion 41a is brought into contact with the input shaft 24b above the second contact portion 41b. This makes it possible to prevent water from accumulating on the surface of the second contact portion 41b.

[0068] Furthermore, the first contact portion 41a is formed to contact the reduced diameter portion 24g, which has a smaller diameter than the portions on both sides of the input shaft 24b in the axial direction, and therefore, the axial movement of the sealing member 40 can be suppressed, and ultimately, the sealing member 40 can be suppressed from falling off the input shaft 24b.

[0069] As described above, the tractor 1 (work vehicle) according to this embodiment has the following features: a power steering controller 24 having an input shaft 24b directed upward; a support member 25 having a cylindrical portion 25c through which the input shaft 24b is inserted from below, the support member 25 supporting the power steering controller 24; a seal member 40 that seals the gap between the cylindrical portion 25c and the input shaft 24b; Equipped with The sealing member 40 is a contact portion 41 arranged to contact the outer peripheral surface of the input shaft 24b; a fixing portion 42 formed of a material having a higher hardness than the contact portion 41 and fixing the contact portion 41 to the support member 25; It is equipped with the following. With this configuration, the gap between the cylindrical portion 25c and the input shaft 24b can be appropriately sealed. That is, the relatively soft contact portion 41 is brought into contact with the input shaft 24b to seal the gap between the cylindrical portion 25c and the input shaft 24b, while the relatively hard fixing portion 42 firmly fixes the contact portion 41. This improves sealing performance. Furthermore, since the relatively soft contact portion 41 is brought into contact with the input shaft 24b, it is possible to suppress an increase in the operating force of the steering wheel 21. Furthermore, since the relatively hard fixing portion 42 is fixed to the support member 25, fixing and positioning relative to the support member 25 can be easily performed.

[0070] In addition, the contact portion 41 is The contact is formed so as to come into contact with a plurality of portions in the axial direction. With this configuration, the contact portion 41 comes into contact with a plurality of portions of the input shaft 24b, thereby improving sealing performance.

[0071] In addition, the contact portion 41 is a first contact portion 41a formed in a flat plate shape perpendicular to the input shaft 24b and in contact with a first portion of the input shaft 24b; a second contact portion (41b) formed below the first contact portion (41a) and in contact with a second portion of the input shaft (24b); It includes: With this configuration, the first contact portion 41a formed in a flat plate shape can prevent water from accumulating on the second contact portion 41b.

[0072] In addition, the input shaft 24b is a reduced diameter portion 24g having a diameter smaller than that of both sides in the axial direction; At least one of the first contact portion 41a and the second contact portion 41b is It is formed so as to come into contact with the reduced diameter portion 24g. With this configuration, the contact portion 41 is brought into contact with the reduced diameter portion 24g, thereby preventing the seal member 40 from moving (falling off from the input shaft 24b).

[0073] The fixing portion 42 is It is fitted onto the outside of the cylindrical portion 25c. With this configuration, the fixing portion 42 can be easily fixed to the cylindrical portion 25c. Furthermore, by covering the cylindrical portion 25c with the fixing portion 42, it is possible to prevent water from entering the inside of the cylindrical portion 25c.

[0074] In addition, at least one of the sealing member 40 and the cylindrical portion 25c has: A drain groove 25f and a groove portion 42f (drain portion) are formed to drain water from the inside to the outside of the cylindrical portion 25c. With this configuration, water that has entered the inside of the cylindrical portion 25c can be discharged.

[0075] Next, the configuration of a tractor 1 according to a second embodiment of the present invention will be described with reference to Figures 7 and 8. In the following, the same components as those in the first embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0076] The tractor 1 according to the second embodiment is provided with a sealing member 50 and a covering member 60 instead of the sealing member 40. The support member 25 is further provided with a positioning pin 25g.

[0077] The positioning pin 25g shown in Fig. 7 is used to position the covering member 60, which will be described later. The positioning pin 25g is formed in a round bar shape and is arranged with its axis oriented in the axial direction of the input shaft 24b. The positioning pin 25g is fixed to the outer peripheral surface of the cylindrical portion 25c by welding or the like. Two positioning pins 25g are provided at positions that sandwich the input shaft 24b therebetween.

[0078] The seal member 50 shown in Fig. 8 is a member for sealing the gap between the cylindrical portion 25c and the input shaft 24b. The seal member 50 is formed in a substantially bottomed cylindrical shape with the bottom surface facing substantially upward. The seal member 50 is provided between the cylindrical portion 25c and the input shaft 24b. The seal member 50 includes a contact portion 51 and a fixing portion 52.

[0079] The contact portion 51 is a portion that is arranged to contact the outer peripheral surface of the input shaft 24b. The contact portion 51 is formed from a material having a relatively low hardness. The contact portion 51 is also formed from a material having elasticity. The contact portion 51 is also formed from a material having flexibility. The contact portion 51 is formed from, for example, soft rubber. The contact portion 51 is formed in a generally truncated conical cylindrical shape whose diameter decreases toward the lower side in the axial direction. The contact portion 51 is disposed so that its center coincides with the axis of the input shaft 24b. The inner diameter at the lower end of the contact portion 51 is formed to be generally the same as the outer diameter of the large diameter portion 24e of the input shaft 24b, and more specifically, is formed to be slightly smaller than the outer diameter of the large diameter portion 24e.

[0080] The contact portion 51 thus formed is provided at its lower end so as to come into contact with the large diameter portion 24e of the input shaft 24b.

[0081] The fixing portion 52 is a portion that fixes the contact portion 51 to the support member 25. The fixing portion 52 is provided so as to fit inside the cylindrical portion 25c. The fixing portion 52 is formed of a material that is harder than the contact portion 51, for example, metal. The fixing portion 52 has an upper surface portion 52a and a side surface portion 52b.

[0082] The upper surface portion 52a constitutes the upper portion of the fixed portion 52. The upper surface portion 52a is formed in a substantially circular ring shape when viewed in the axial direction. The upper surface portion 52a is provided so that the center of the circle coincides with the axis of the input shaft 24b. The upper surface portion 52a is formed so that the end portion on the inner periphery is bent obliquely downward. The end portion on the inner periphery of the upper surface portion 52a is fitted into the contact portion 51 and fixed.

[0083] The side surface portion 52b is a portion that constitutes the side of the fixing portion 52. The side surface portion 52b is formed to extend downward in the axial direction from the outer peripheral end of the upper surface portion 52a. The outer peripheral surface of the side surface portion 52b is provided so as to contact the inner peripheral surface of the cylindrical portion 25c.

[0084] The covering member 60 is a member that covers the cylindrical portion 25c from above. The covering member 60 is formed in a flat plate shape. The covering member 60 has an outer shape that is substantially circular when viewed in the axial direction. The covering member 60 is formed to have an outer diameter that is larger than the outer diameter of the sealing member 50.

[0085] The covering member 60 is disposed so as to be inclined with respect to the horizontal direction. Specifically, the covering member 60 is disposed so that the circular center coincides with the axis of the input shaft 24b, and is inclined so that the rear portion is lower than the front portion. The covering member 60 has a through hole 61, a positioning hole 62, and a protrusion 63.

[0086] The input shaft 24b is inserted through the through hole 61. The through hole 61 is formed in the center of the covering member 60 as viewed in the axial direction. The through hole 61 is formed to have a diameter that is larger than the outer diameter of the reduced diameter portion 24g of the input shaft 24b and smaller than the outer diameter of the large diameter portion 24e.

[0087] The positioning holes 62 shown in FIG. 7 are used to position the covering member 60. Two positioning holes 62 are formed at positions corresponding to the positioning pins 25g. The positioning holes 62 are formed in a circular shape when viewed in the axial direction. The positioning holes 62 are formed to have an inner diameter that is approximately the same as the outer diameter of the positioning pins 25g. Two positioning pins 25g are inserted into each of the two positioning holes 62.

[0088] The protruding portion 63 is formed at the lower end (lowest position) in the tilt direction of the covering member 60 so as to protrude in the radial direction of the cylindrical portion 25c.

[0089] The seal member 50 thus formed can be fixed to the cylindrical portion 25c (support member 25) with the contact portion 51 in contact with the input shaft 24b by fitting the fixing portion 52 inside the cylindrical portion 25c. In this way, the relatively soft contact portion 51 can be brought into contact with the input shaft 24b to seal the gap between the cylindrical portion 25c and the input shaft 24b, while the relatively hard fixing portion 52 can firmly fix the contact portion 51. This can improve sealing performance.

[0090] Furthermore, by providing the covering member 60 so as to cover the sealing member 50, it is possible to prevent water from accumulating on the surface of the sealing member 50 (particularly the contact portion 51). Furthermore, since the covering member 60 is inclined rearward and downward relative to the horizontal direction, water adhering to the surface of the covering member 60 moves rearward along the surface of the covering member 60. A protrusion 63 that protrudes radially outward is formed at the rear end (lowest position) of the covering member 60, so that water adhering to the covering member 60 can be collected and dropped by the protrusion 63 that is separated from the cylindrical portion 25c. This makes it possible to prevent water adhering to the surface of the covering member 60 from penetrating into the cylindrical portion 25c.

[0091] Additionally, the covering member 60 is positioned relative to the cylindrical portion 25c by the positioning pin 25g and the positioning hole 62. This allows the protruding portion 63 to be stably positioned at the lower end of the covering member 60 in the tilt direction.

[0092] As described above, the fixing portion 52 is It is fitted inside the cylindrical portion 25c. With this configuration, the fixing portion 52 can be easily fixed to the cylindrical portion 25c.

[0093] In addition, the tractor 1 (work vehicle) according to this embodiment is The device further includes a covering member 60 that covers the cylindrical portion 25c from above. This configuration can prevent water from entering the inside of the cylindrical portion 25c.

[0094] Moreover, the covering member 60 is The plate is formed in a flat shape and is arranged so as to be inclined with respect to the horizontal direction. The covering member 60 has A protrusion 63 that protrudes in the radial direction of the cylindrical portion 25c is formed at the lower end of the covering member 60 in the inclined direction. With this configuration, water adhering to the covering member 60 can be collected and dropped at the protruding portion 63 located away from the cylindrical portion 25c, thereby preventing water from penetrating into the inside of the cylindrical portion 25c.

[0095] The tractor 1 according to this embodiment is one embodiment of a work vehicle according to the present invention. The drain groove 25f according to this embodiment is one embodiment of the drain portion according to the present invention.

[0096] Although the embodiments of the present invention have been described above, the present invention is not limited to the above configurations, and various modifications are possible within the scope of the invention described in the claims.

[0097] For example, in the first embodiment, the contact portion 41 is formed so as to contact two locations in the axial direction of the input shaft 24b, but it may also be formed so as to contact three or more locations.

[0098] In the first embodiment, the contact portion 41 is in contact with the reduced diameter portion 24g and the large diameter portion 24e, but it may be in contact with other portions of the input shaft 24b. When the contact portion 41 is in contact with the reduced diameter portion 24g, either the first contact portion 41a or the second contact portion 41b may be in contact with the reduced diameter portion 24g.

[0099] In addition, in the first embodiment, the contact portion 41 and the fixed portion 42 are formed integrally, but the contact portion 41 and the fixed portion 42 do not necessarily have to be formed integrally, and may be formed separably.

[0100] Furthermore, in each of the above embodiments, drain groove 25f is formed in a groove shape, but it may be formed in a hole shape that penetrates a part of the side surface of tubular portion 25c. Furthermore, in the first embodiment, groove portion 42f is formed in a groove shape, but it may be formed in a hole shape that penetrates a part of side surface portion 42b of fixing portion 42. Furthermore, drain portions (drain groove 25f and groove portion 42f) may be provided in either seal member 40 or tubular portion 25c, or may be provided in both seal member 40 and tubular portion 25c.

[0101] Furthermore, the shapes, structures, etc. of the parts exemplified in the above embodiments are merely examples, and the configuration of each part can be changed as desired.

[0102] In addition, in each of the above embodiments, the tractor 1 is used as an example of a work vehicle, but the work vehicle is not limited to this. For example, the work vehicle may be other agricultural vehicles, construction vehicles, industrial vehicles, etc. [Explanation of symbols]

[0103] 1 Tractor 24 Power steering controller 24b input shaft 24g reduced diameter part 25 Support member 25c Cylindrical part 25f Drain 40 sealing material 41 Contact part 41a First contact part 41b Second contact part 42 Fixed part 42f Groove 50 sealing material 51 Contact part 52 Fixed part 60 Covering material 63 Protrusion

Claims

1. a power steering controller having an input shaft directed upward; a support member having a cylindrical portion through which the input shaft is inserted from below, the support member supporting the power steering controller; a seal member that closes a gap between the cylindrical portion and the input shaft; Equipped with The sealing member is a contact portion arranged to contact an outer peripheral surface of the input shaft; a fixing portion formed of a material having a higher hardness than the contact portion and fixing the contact portion to the support member; A work vehicle equipped with:

2. The contact portion is The input shaft is formed so as to come into contact with a plurality of portions in the axial direction thereof. The work vehicle according to claim 1 .

3. The contact portion is a first contact portion formed in a flat plate shape perpendicular to the input shaft and in contact with a first portion of the input shaft; a second contact portion formed below the first contact portion and in contact with a second portion of the input shaft; Including, The work vehicle according to claim 2 .

4. The input shaft a reduced diameter portion having a diameter smaller than that of portions on both sides in the axial direction; At least one of the first contact portion and the second contact portion is The reduced diameter portion is formed to contact the reduced diameter portion. The work vehicle according to claim 3 .

5. The fixing portion is The cylindrical portion is fitted to the outside of the cylindrical portion. The work vehicle according to claim 1 .

6. The fixing portion is It is fitted inside the cylindrical part, The work vehicle according to claim 1 .

7. Further comprising a covering member that covers the cylindrical portion from above. The work vehicle according to claim 6.

8. The covering member is The plate is formed in a flat shape and is arranged so as to be inclined with respect to the horizontal direction. The covering member includes: A protrusion protruding in a radial direction of the cylindrical portion is formed at a lower end of the covering member in the inclined direction. The work vehicle according to claim 7.

9. At least one of the sealing member and the cylindrical portion has A drainage section is formed to drain water from the inside to the outside of the cylindrical section. The work vehicle according to claim 1 .

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