WO2019054247A1

WO2019054247A1 - Work vehicle

Info

Publication number: WO2019054247A1
Application number: PCT/JP2018/032861
Authority: WO
Inventors: 翔一中村; 健太大西
Original assignee: ヤンマー株式会社
Priority date: 2017-09-13
Filing date: 2018-09-05
Publication date: 2019-03-21
Also published as: KR20230037682A; TW201919468A; CN111094107B; CN111094107A; KR102331676B1; KR20210144921A; TWI683614B; KR20190104573A; CN114802427A

Abstract

The purpose of the present invention is to efficiently arrange a power steering device inside the engine compartment so as to ensure sufficient leg room for a user. The present invention comprises: an engine 6; a transmission case 7 to which the drive from the engine 6 is transmitted; a steering shaft 41 for transmitting the steering force of a steering wheel 15 to wheels; and a power steering device 61 for applying steering assisting force to the steering shaft 41. The power steering device 61 is configured as an electrically-operated device which applies the drive power of an electric motor 62 to the steering shaft 41 supported by the top of the transmission case 7, wherein the engine 6, steering shaft 41, and power steering device 61 are arranged inside the engine compartment and the electric motor 62 is disposed rearwardly of the engine 6 and forwardly of the steering shaft 41 in terms of the front-rear direction.

Description

Work vehicle

The present invention relates to a work vehicle provided with a steering shaft for transmitting a steering force of a steering wheel to wheels and a power steering device for applying a steering assist force to the steering shaft.

Among the working vehicles as described above, there is known a power steering apparatus that is configured as an electric type provided with an electric motor and applies a driving force of the electric motor to a steering shaft as a steering assist force (for example, Patent Document 1).

In the work vehicle described in Patent Document 1, a steering handle is connected to an upper portion of a steering shaft, and the steering shaft is provided in a rearward inclined posture positioned on the front side toward the lower side. The power steering apparatus includes an electric motor in a state in which a pinion gear is meshed with a drive gear provided at an intermediate portion of a steering shaft, and the steering motor uses the driving force of the electric motor as a steering assist force by operating the electric motor. Granted to. As described above, the steering assist force by the electric motor is applied from the lateral side orthogonal to the axial center direction of the steering shaft, and the arrangement position of the electric motor is on the rear side of the steering shaft in the longitudinal direction. There is.

In the work vehicle as described above, the steering shaft is supported on the upper part of the transmission case, and the steering handle is supported on the upper end of the steering shaft (see, for example, Patent Document 2).

In the work vehicle described in Patent Document 2, a power steering device is disposed at an intermediate portion of a steering shaft, and the steering shaft is divided into an upper shaft and a lower shaft by the power steering device. The upper shaft is supported within the upper handle post, the steering handle is connected to the upper end of the upper handle post, and the power steering device is connected to the lower end of the upper handle post. The lower shaft is supported in the lower handle post, the power steering apparatus is connected to the upper end of the lower handle post, and the upper portion of the transmission case is connected to the lower end of the lower handle post.

JP 2007-37510 A JP 2007-38725 A

In the work vehicle as described above, since various devices such as an engine, a steering shaft, a power steering device and the like are arranged in the bonnet, efficient arrangement of various devices in a limited space in the bonnet is required. ing. However, in the thing of the said patent document 1, since the electric motor is arrange | positioned at the back side rather than a steering shaft, it becomes a shape where the bonnet extended to the back side rather than a steering shaft. Therefore, the bonnet projects to the foot of the user who operates the steering handle, and a sufficient space can not be secured at the foot of the user, which gives the user a feeling of pressure.

In view of this situation, the main object of the present invention is to provide a work vehicle capable of efficiently arranging a power steering device in a bonnet to secure a sufficient space at the foot of a user.

In the work vehicle described in Patent Document 1 described above, since the power steering apparatus includes the electric motor, heat and water vapor generated by the electric motor and the like may be accumulated inside the power steering apparatus. It is required to release or release heat. That is, since the electric power steering apparatus and the electric motor and other components are usually accommodated in the case, heat and water vapor generated by the electric motor and the like are accumulated in the case. However, Patent Document 1 does not disclose that the heat or water vapor inside the power steering apparatus is dissipated or released to the outside, and the inside of the power steering apparatus becomes hot, or the power steering apparatus Accumulation of water such as dew condensation water inside may adversely affect the electric motor and the like.

Another object of the present invention is to provide a work vehicle capable of releasing or releasing heat and water vapor inside the power steering apparatus to the outside while suppressing the complication of the configuration and the increase in the number of members.

In the work vehicle described in Patent Document 2, the upper handlebar post and the power steering device are connected in a state of being in direct contact with each other by the fastening of the bolt and nut. Thus, when an external force acts on the steering handle when the user operates the steering handle, the external force is directly transmitted to the power steering apparatus through the upper handle post. Therefore, a large external force is applied to the power steering apparatus, which adversely affects the power steering apparatus.

Recently, as a power steering apparatus, there may be adopted an electric type that applies a driving amount of an electric motor to a steering shaft as a steering assist force. In the electric power steering apparatus, in particular, reduction of external force applied to the power steering apparatus is required since precision parts such as an electric motor are provided.

Another object of the present invention is to provide a work vehicle capable of reducing external force applied to a power steering apparatus.

According to a first aspect of the present invention, an engine, a transmission case to which driving force from the engine is transmitted, a steering shaft for transmitting steering force of a steering wheel to a wheel, and steering assist force to the steering shaft Equipped with a power steering device,
The power steering apparatus is configured to be electrically driven to apply a driving force of an electric motor to the steering shaft.
The steering shaft is supported at an upper portion of the transmission case.
In the bonnet, the engine, the steering shaft, and the power steering device are disposed;
The electric motor is disposed at the rear side of the engine and at the front side of the steering shaft in the front-rear direction.

According to this configuration, the electric motor is disposed rearward of the engine and forward of the steering shaft in the front-rear direction. Therefore, the space between the engine and the steering shaft is effectively utilized to perform electric driving. The motor can be disposed, and the power steering device can be efficiently disposed in the bonnet. As a result, it is possible to prevent the bonnet from having a shape that protrudes rearward relative to the steering shaft, and to secure a sufficient space at the foot of the user who operates the steering wheel.

According to a second aspect of the present invention, the bonnet is provided with a shift case provided with a shift mechanism for shifting an output from the transmission case in accordance with a shift operation.
The transmission case is disposed at an upper portion of the transmission case.
The electric motor is located on the upper side of the transmission case.

According to this configuration, in the bonnet, not only the electric motor but also the shift case can be disposed by effectively utilizing the space above the transmission case. Moreover, since the electric motor is disposed above the shift case and the electric motor and the shift case are disposed at different positions in the vertical direction, the interference between the electric motor and the shift case is suppressed, The motor and the shift case can be arranged efficiently. Therefore, the engine, the steering shaft, the power steering device, and the transmission case can be efficiently disposed by effectively utilizing the space in the bonnet.

A third characterizing feature of the present invention is that the electric motor and the shift case are disposed on the same side in the left-right direction with respect to the steering shaft.

According to this configuration, since the electric motor and the shift case can be collectively disposed by utilizing the space on one side in the left-right direction with respect to the steering shaft, on the other side in the left-right direction with respect to the steering shaft There is no need to secure an arrangement space for the electric motor, the gear change case, etc. Thus, a space can be secured on the other side in the left-right direction with respect to the steering shaft, and the space can be utilized for the space when performing maintenance work such as an engine or various other applications.

According to a fourth aspect of the present invention, there is provided a flywheel cover which covers a flywheel of the engine from above.
The electric motor is located above the tangent of the flywheel passing through the outer peripheral portion of the flywheel and the lower end of the flywheel cover.

According to this configuration, since the flywheel cover covers the flywheel from the upper side, it is possible to prevent the splashing of muddy water and the like above by the flywheel cover. The electric motor is disposed above the tangent of the flywheel passing through the outer peripheral portion of the flywheel and the lower end portion of the flywheel cover, and therefore, the motor is driven to a position where splashing of muddy water is prevented by the flywheel cover. A motor can be arranged, and it is possible to prevent the electric motor from being adversely affected by splashing of muddy water or the like.

According to a fifth aspect of the present invention, there is provided a support member for supporting the steering shaft and the power steering device.
The support member supports the steering shaft in a state in which the steering shaft is positioned in a hollow space therein, and the power steering apparatus in a state in which the hollow space therein is in communication with the inside of the power steering apparatus Configured to support the
It is in the point provided with the exterior open part which opens the inside of the above-mentioned support member outside.

According to this configuration, the support member supports the power steering device in a state where the hollow space therein and the inside of the power steering device are in communication with each other. Heat can be released or released into the hollow space inside. And since the external opening part which opens the inside of a supporting member to the exterior is provided, the heat released to the inside of a supporting member and the released water vapor can be radiated or released outside by the external opening part. . As described above, heat and water vapor in the power steering apparatus can be efficiently dissipated or released to the outside while utilizing the hollow space in the support member. In addition, since the support member is a member for supporting the steering shaft and the power steering device, the support member can be used as a structure for radiating or releasing heat and water vapor inside the power steering device to the outside. be able to. Therefore, heat and water vapor in the power steering apparatus can be dissipated or released to the outside while suppressing the complication of the configuration and the increase in the number of members. Furthermore, although water or the like enters the inside of the support member even if water or the like infiltrates from the external opening portion, the water reaches the power steering device, for example, by disposing the power steering device on the upper portion of the support member. Can be prevented. Therefore, while heat or steam inside the power steering apparatus can be dissipated or released to the outside, it is possible to appropriately prevent the entry of water or the like into the power steering apparatus.

According to a sixth aspect of the present invention, the transmission case supports the lower end portion of the support member and transmits a driving force to the wheels.
The communication connection part which connects the said transmission case and the said supporting member in the state which makes the inside of the said transmission case and the inside of the said supporting member connect is provided.

According to this configuration, the communication connection portion connects the transmission case and the support member in a state where the inside of the transmission case and the inside of the support member are in communication with each other, so the air inside the transmission case is supported through the communication connection portion. It can be supplied to the inside of the component. Then, the air inside the transmission case supplied to the inside of the support member can be discharged to the outside by the external opening portion. This can prevent the internal pressure of the transmission case from becoming high. Moreover, not only the support member but also the external opening portion can be used as a configuration for discharging the air inside the mission case to the outside, and while the configuration is simplified, the heat in the power steering apparatus and the It is possible to realize both the heat release or release of water vapor to the outside and the discharge of air inside the transmission case to the outside.

According to a seventh characterizing feature of the present invention, the connection portion of the communication connection portion to the support member is disposed above the connection portion of the external opening portion to the support member.

In the case where water or the like infiltrates from the outer opening, the water infiltrates into the inside of the support member. Therefore, according to the present configuration, the connection portion of the communication connection portion to the support member is disposed above the connection portion of the external open portion to the support member, whereby the water etc. which has entered the inside of the support member is in communication connection It can be prevented from entering the inside of the mission case through the unit. As a result, with a simple configuration in which the connection points of the communication connection portion and the external opening portion are adjusted in the vertical direction, appropriate measures can be taken against the infiltration of water or the like from the external opening portion.

According to an eighth characterizing feature of the present invention, in the connection portion of the communication connection portion to the support member and the connection portion of the external opening portion to the support member, in the front-rear direction across the central portion of the support member in side view It is in the point arrange | positioned in the separated state.

According to this configuration, the connection portion of the communication connection portion to the support member and the connection portion of the external open portion to the support member are arranged in a state of being separated in the front-rear direction across the central portion of the support member in side view. Using the length of the support member in the front-rear direction, the connection portion of the communication connection portion can be disposed at a position closer to the transmission case side, and the connection portion of the external opening portion can be disposed at a position closer to the outside it can. Thus, the lengths of the communication connection portion and the external open portion can be shortened as much as possible, and the configuration can be simplified.

According to a ninth characterizing feature of the present invention, the power steering apparatus is disposed in the middle of the steering shaft.
A lower side support member extending in an axial direction of the steering shaft in a state of surrounding the lower side portion of the steering shaft with respect to the power steering device;
And an upper support member connected to the steering handle via an intermediate member and extending in the axial direction of the steering shaft so as to surround the upper portion of the steering shaft above the power steering device.
The steering shaft and the lower side support member are supported on the top of the transmission case,
The power steering device is supported by the upper portion of the lower side support member,
The upper support member is supported at a position above the support position of the power steering apparatus at an upper portion of the lower support member.

According to the present configuration, it is possible to use the lower side support member as a member for supporting the power steering apparatus while being able to include the steering shaft in a state of surrounding the steering shaft by the lower side support member and the upper side support member. Can. The upper support member is supported at the upper part of the lower support member at a position deviated from the support position of the power steering apparatus, so that the power transmitted by the upper support member is directly applied to the power steering apparatus. While preventing, both the power steering device and the upper side support member can be supported by the lower side support member. Therefore, even when an external force acts on the steering handle when the user operates the steering handle, the external force is transmitted to the upper support member via the intermediate member, and the external force transmitted to the upper support member is Direct transmission to the power steering device can be prevented. From the above, the external force applied to the power steering device can be reduced while efficiently supporting both the power steering device and the upper side supporting member by the lower side supporting member.

According to a tenth characterizing feature of the present invention, the upper side support member supports the power steering device in a state of surrounding the power steering device at a shaft side support member surrounding the steering shaft and above the lower side support member. And a support base connected to a position out of position, wherein the shaft side support member is connected to and supported by the upper portion of the support base.

According to this configuration, the shaft side support member can be a member having a shape or configuration suitable for surrounding the steering shaft, and the support base supports the upper side support member in a state surrounding the power steering apparatus. Can have a shape or configuration suitable for the Thus, by connecting the support base to the upper portion of the lower support member, the upper support member can appropriately support the steering shaft while improving the support strength of the upper support member. it can. Moreover, by using the upper side support member as a separate body from the shaft side support member and the support base, it becomes easy to handle, and the assembly work and the like of the shaft side support member and the support base can be easily performed.

According to an eleventh aspect of the present invention, there is provided a reinforcing member for connecting the shaft side supporting member and the supporting base, wherein the reinforcing member is a supporting member for supporting the steering shaft and the power steering apparatus. Other members are supported.

According to this configuration, since the reinforcing member connects the shaft side support member and the support base, it is possible to reinforce the support of the shaft side support member, and the reinforcing member can be a member other than the support member (for example, an electrical component). It can be used as a member for supporting. This makes it possible to appropriately reinforce the support of the shaft side support member while simplifying the configuration.

According to a twelfth characterizing feature of the present invention, the shaft side support member is connected to an operating tool support frame for supporting the operating tool.

According to this configuration, since the operation tool support frame is connected to the shaft side support member, the operation tool support frame and the shaft side support member can be integrally provided. Thus, in addition to the steering shaft, the operation tool disposed around the steering handle can be integrally supported by the upper side support member, and the support configuration can be simplified. Moreover, not only the external force acting on the steering handle but also the external force acting on the operation tool can be prevented from being directly transmitted to the power steering device through the upper side support member, and the external force acting on the power steering device It can be reduced.

Side view showing the entire schematic configuration of the rice transplanter Left side view showing the main part of the rice transplanter with the bonnet removed Top view showing the main part of the rice transplanter with the bonnet removed A perspective view showing the lower part of the dashboard with the back of the bonnet removed A diagram showing a schematic configuration of a transmission mechanism Front view seen from the front side showing a schematic configuration of a steering system The perspective view seen from the back side which shows schematic structure of a steering system Right side view showing the main part of the steering system Cross section showing the main part of the steering system

An embodiment of a work vehicle according to the present invention will be described based on the drawings.
As shown in FIG. 1, the rice transplanter 1 as a work vehicle is provided with a traveling machine body 2 and a seedling planting device 3, and the seedling planting device 3 is supported by the rear of the traveling machine body 2 so as to be able to move up and down. ing. The seedling planting apparatus 3 includes a seedling platform 31 and a plurality of seedling planting claws 32 and is configured to be able to plant the seedlings of the seedling platform 31 in the field by the plurality of seedling planting claws 32.

Incidentally, although the rice transplanter 1 is illustrated as a work vehicle in this embodiment, a riding type work vehicle such as a tractor, a combine, a civil engineering / architect work device, a snow removal vehicle, etc. other than the rice transplanter 1 is applicable.

The traveling body 2 is provided with a vehicle body frame 5 extending in the front-rear direction, and various devices are supported by the vehicle body frame 5. An engine 6 (see FIGS. 2 and 3) serving as a drive source is supported on the front side of the body frame 5, and a transmission case 7 is supported on the rear side of the engine 6. At the front of the traveling vehicle 2, a bonnet 10 covering the engine 6 is provided. Incidentally, FIG. 2 is a left side view showing the inside of the bonnet 10 and the mission case 7 with the bonnet 10 removed, and FIG. 3 is the inside of the bonnet 10 with the bonnet 10 removed and the mission case 7 FIG.

Although not shown, the transmission case 7 is provided with, for example, a hydraulic-mechanical continuously variable transmission (HMT: Hydro Mechanical Transmission), a transmission mechanism for shifting the power from the HMT to a plurality of stages, etc. . Incidentally, HMT is a hydraulic continuously variable transmission (HST: Hydro Static Transmission) capable of continuously changing the power from engine 6 and a planet capable of combining the power from engine 6 and the power from HST. It is configured by combining with a gear mechanism.

A front axle case (not shown) is supported at the front of the body frame 5, and front wheels 8 are attached to the left and right sides of the front axle case. A rear axle case (not shown) is supported at the rear of the body frame 5, and rear wheels 9 are attached to the left and right sides of the rear axle case.

As shown in FIG. 2, the power of the engine 6 is transmitted to the transmission case 7 via the power transmission belt 22, and the rice transplanter 1 outputs power from the transmission case 7 by the HMT, the transmission mechanism, etc. inside the transmission case 7. Is configured to be freely variable. The output from the transmission case 7 can be transmitted to the left and right front wheels 8 and the left and right rear wheels 9, respectively, and the front wheels 8 and the rear wheels 9 can be rotationally driven.

As indicated by a dotted line in FIG. 1, a mounting frame 11 extending in the vertical direction is disposed at the front of the vehicle body frame 5, and a spare seedling support 12 is attached to the mounting frame 11. The spare seedling carrier 12 is disposed on the left and right sides of the bonnet 10. The spare seedlings are placed on the spare seedling platform 12 so that the seedlings can be supplied to the seedling planting device 3.

A driving operation unit 13 is disposed at an intermediate portion in the front-rear direction of the vehicle body frame 5. A dashboard 14 is disposed on the front side of the driving operation unit 13 and at the rear end of the hood 10. A steering wheel 15 is disposed at a central portion in the left-right direction of the dashboard 14, and a driver's seat 16 is disposed on the rear side of the steering wheel 15. A vehicle body cover 17 is provided to cover the vehicle body frame 5 on both sides in the left-right direction of the bonnet 10 and the rear portion thereof. The driving operation unit 13 is provided with various operation tools such as the main shift lever 18, the brake pedal 19 (see FIG. 4), the shift pedal 20 (see FIG. 4), and the elevating cross lever 21 (see FIG. 4). .

Incidentally, to describe the operation tool, the main shift lever 18 is a lever for shifting the traveling speed of the traveling body 2 including forward, neutral and reverse. The brake pedal 19 is a pedal for performing a braking operation for applying a braking force to the front wheel 8 and the rear wheel 9. The shift pedal 20 is a pedal for shifting the output of the transmission case 7 to shift the traveling speed of the traveling body 2. The lifting cross lever 21 is a lever for lifting and lowering the seedling planting device 3 by the lifting mechanism 4. The raising and lowering cross lever 21 is configured so as to be able to swing in both the front and rear direction and in the left and right direction, and is provided with a detection sensor and the like for detecting at which position the swing operation is performed.

Hereinafter, based on FIG.6 and FIG.7, schematic structure of the steering system for steering operation of the front wheel 8 (wheel) by rotation operation of the steering handle 15 is demonstrated.

A steering shaft 41 is provided which is connected to the central portion of the steering wheel 15 and transmits the steering force of the steering wheel 15 to the front wheels 8. Since the steering shaft 41 is covered by the support member at its periphery, in FIGS. 2, 6 and 7, the covered portion is indicated by a dotted line. The steering shaft 41 is provided to extend in the vertical direction, and its upper end is connected to the steering handle 15. The lower end portion of the steering shaft 41 is connected to the upper portion of the transmission case 7 via the seal member 42, and the steering shaft 41 is supported on the upper portion of the transmission case 7.

The steering shaft 41 is divided into three shafts of an upper side shaft 41a, an intermediate shaft 41b, and a lower side shaft 41c in order from the upper side. The upper side shaft 41a is disposed in a rearward inclined posture positioned on the rear side toward the upper side, and the intermediate shaft 41b and the lower side shaft 41c are disposed in an upright posture extending along the vertical direction. The upper side shaft 41a and the intermediate shaft 41b are connected to be integrally rotated by the joint member 43, and the power steering device 61 is disposed between the intermediate shaft 41b and the lower side shaft 41c.

When the user rotates the steering handle 15, the steering force associated with the rotation operation is transmitted to the steering shaft 41. A power steering device 61 is provided at an intermediate portion of the steering shaft 41, and the power steering device 61 is provided with an electric motor 62, and the electric power is applied to the steering shaft 41 as a steering assist force. The formula is organized. Therefore, in addition to the steering force of the steering handle 15 by the user, the steering assist force by the electric motor 62 in the power steering device 61 is applied to the steering shaft 41. The steering shaft 41 is rotationally driven by the steering force by the steering handle 15 and the steering assist force by the power steering device 61, and the pitman arm (not shown) is pivoted by the rotational drive of the steering shaft 41 And the left front wheel 8 is steered.

The power steering device 61 includes a power steering case 63 disposed between the intermediate shaft 41 b and the lower shaft 41 c and an electric motor 62. As shown in FIG. 9, the power steering case 63 is formed in a circular shape in a plan view in which a small diameter cylindrical portion is disposed above the large diameter cylindrical portion, and extends upward from the upper end portion of the power steering case 63. The input portion 64 is disposed, and the output portion 65 is disposed in a state of extending downward from the bottom surface portion. In the power steering case 63, although not shown in detail, for example, a shaft portion that transmits the steering force (rotational driving force) input from the input portion 64 and outputs it to the output portion 65; A drive gear, a torque sensor, etc. arranged in the middle part are accommodated. Further, as shown in FIG. 9, the power steering device 61 is configured such that the input unit 64 is connected to the intermediate shaft 41b, and the steering force (rotational driving force) is transmitted from the intermediate shaft 41b to the input unit 64. It is done. Further, as shown in FIG. 9, in the power steering device 61, the output portion 65 is connected to the lower shaft 41c via the joint member 52, and the output portion 65 is connected to the lower shaft 41c via the joint member 52. The steering force (rotational driving force) is transmitted.

As shown in FIGS. 7 and 9, the electric motor 62 includes, for example, an output gear meshing with a drive gear in the power steering case 63, and the drive gear in the power steering case 63 is rotatably driven. ing. When a steering force (rotational driving force) accompanying the rotation operation of the steering handle 15 is input from the intermediate shaft 41b to the input unit 64, the power steering device 61 uses the steering force (rotational driving force) to assist steering by the electric motor 62. A steering force (rotational driving force) to which a force (rotational driving force) is applied is output from the output unit 65 and transmitted to the lower side shaft 41 c via the joint member 52.

The support structure of the steering shaft 41 will be described.
As shown in FIGS. 6 and 7, the upper side support member 44 rotatably supporting the steering shaft 41 via a bush or the like (not shown) and the steering shaft 41 are disposed inside to support the power steering apparatus 61. And a lower side supporting member 45. Each of the upper side support member 44 and the lower side support member 45 is configured to extend in the axial direction of the steering shaft 41 so as to cover the steering shaft 41.

The upper side support member 44 is provided in a state of covering the outer peripheral portion of the upper side shaft 41 a and the intermediate shaft 41 b (a portion on the steering shaft 41 above the power steering device 61). The lower side support member 45 is provided in a state of covering the outer peripheral portion of the lower side shaft 41c (a lower side portion of the steering shaft 41 than the power steering device 61).

The upper side support member 44 corresponds in order from the upper side to a first support member 46 covering a portion corresponding to the upper side shaft 41 a, a second support member 47 covering a portion corresponding to the joint member 43, and an intermediate shaft 41 b. A third support member 48 covering the portion to be moved and a support base 66 are provided. The upper support member 44 is supported by the support base 66 on the upper portion of the lower support member 45.

The first support member 46 is formed in a cylindrical shape that covers the entire length in the circumferential direction of the upper side shaft 41a, and rotatably supports the upper side shaft 41a via a bush or the like (not shown). Thus, the upper support member 44 is connected to the steering handle 15 via the upper shaft 41a and an intermediate member such as a bush. An upper end portion of the second support member 47 is connected to the first support member 46, and the second support member 47 covers the front, upper, and left and right sides of the joint member 43 and opens the rear side of the joint member 43 It is configured in the shape of An upper end portion of the third support member 48 is connected to the second support member 47, covers the left and right sides of the intermediate shaft 41b, and extends in the front-rear direction to open the front side and the rear side of the intermediate shaft 41b. It consists of a plate-like body.

As shown in FIG. 9, the lower side support member 45 is formed in a cylindrical shape whose inside is a hollow space 45a, and the lower side shaft 41c is disposed in the hollow space 45a. As shown in FIGS. 6 and 9, the seal member 42 is disposed below the lower support member 45, and the seal member 42 is disposed between the lower support member 45 and the transmission case 7 There is. The sealing member 42 seals (blocks) a portion communicating with the hollow space 45 a in the lower side support member 45, thereby shielding the inside of the transmission case 7 from the hollow space 45 a in the lower side support member 45. The movement of water, hydraulic oil and the like between the inside of the transmission case 7 and the hollow space 45 a inside the lower side support member 45 is prevented.

As shown in FIGS. 7-9, the lower side support member 45 is provided with a horizontally extending flange portion 49 at its upper end. The flange portion 49 is formed wider than the outer diameter of the lower side support member 45 in the front-rear direction and the left-right direction. The lower side support member 45 is provided with an inclined rib portion 51 extending forward or backward from the outer peripheral portion thereof, and the upper end portion of the rib portion 51 is connected to the flange portion 49. The rib portion 51 is provided on the front side of the lower side support member 45 at a distance in the left-right direction. The rib portion 51 is also provided on the rear side of the lower side support member 45 at a distance in the left-right direction.

The support structure of the power steering device 61 will be described.
The power steering case 63 of the power steering device 61 is mounted on and supported by the flange portion 49 of the lower side support member 45, as shown in FIGS. As shown in FIG. 9, an opening 50 for opening the hollow space 45a inside the lower support member 45 is formed at the center side of the flange 49, and the opening 50 is closed from the upper side. Power steering case 63 is disposed. The power steering case 63 is provided with an output portion 65 projecting downward, and the output portion 65 is disposed so as to extend through the opening 50 into the hollow space 45 a. Thereby, the output portion 65 and the lower side shaft 41c are connected via the joint member 52, and the steering force (rotational driving force) output from the output portion 65 can be transmitted to the lower side shaft 41c via the joint member 52. Is configured. An opening 67 is formed around the output portion 65 in the power steering case 63, and the power steering device 61 is formed by the opening 67 of the power steering case 63 and the opening 50 of the flange 49 of the lower side support member 45. The hollow space 45a of the lower support member 45 communicates with the inner space of the lower support member 45.

Thus, the power steering case 63 is mounted and supported on the flange 49 in a state where the inside thereof communicates with the hollow space 45 a inside the lower side support member 45. The lower side support member 45 supports the power steering device 61 in a state in which the steering shaft 41 is disposed in the hollow space 45a inside and the hollow space 45a inside is communicated with the inside of the power steering device 61. It is a configured support member.

The electric motor 62 is connected to and supported by the power steering case 63 so as to extend laterally to the side of the power steering case 63. The electric motor 62 is provided such that the inside thereof communicates with the inside of the power steering case 63.

A description of the upper side support member 44 will be added.
The upper side support member 44 is integrally provided with an operation tool support structure for supporting operation tools such as the main transmission lever 18 and the raising and lowering cross lever 21. As shown in FIGS. 6 and 7, at the front end portion of the second support member 47 in the upper side support member 44, a rod-like operation tool support frame 71 extending in the left-right direction is provided. A lever guide 72 of the main shift lever 18 is supported at the left end portion of the operation tool support frame 71, and the main shift lever 18 is supported by the lever guide 72. At the right end portion of the operation tool support frame 71, a support bracket 73 is provided to support a lifting cross lever 21 (see FIG. 4) and a detection sensor for detecting the position of the lifting cross lever 21.

As described above, the upper side support member 44 includes the first support member 46, the second support member 47, and the third support member 48, as shown in FIG. The shaft side support member that rotatably supports the steering shaft 41 in a state of surrounding the steering shaft 41 is configured by the to 48. In the upper side support member 44, shaft side support members (first to third support members 46 to 48) are connected to and supported by the upper portion of the support base 66, and the lower end portion of the support base 66 is connected to the lower side support member 45. The upper support member 44 is supported by the upper portion of the lower support member 45 via the support base 66 by being connected to the upper portion of the lower support member 44.

The support base 66 is provided to cover the power steering device 61, as shown in FIG. The support base 66 is configured to cover the outer periphery of the power steering case 63 at a distance (without contacting). The support base 66 covers the both sides and upper side of the power steering case 63 in the left-right direction, and is formed in a U shape in a front-rear direction view in which both sides in the front-rear direction are opened. In the support base 66, various types are provided for the left wall 66a covering the left side of the power steering case 63, the right wall 66b covering the right side of the power steering case 63, and the upper wall 66c covering the upper portion of the power steering case 63. Openings and cutouts are formed for inserting the various members and arranging the various members at desired positions. Thus, the support base 66 is disposed without interference with the power steering device 61.

The lower end portion of the support base 66 is connected to and supported by the flange portion 49 of the lower side support member 45 by fastening of a bolt and a nut. The support base 66 is formed in a rectangular shape in plan view, and the width in the front-rear direction and the left-right direction is configured to be the same as or substantially the same width as the flange portion 49. Further, the four corners of the support base 66 and the flange portion 49 serve as connection and support locations for the flange portion 49 of the lower side support member 45.

As shown in FIGS. 7 and 8, the upper support member 44 is connected to the flange 49 of the lower support member 45 by a support base 66 disposed at its lower end. The first support member 46, the second support member 47, and the third support member 48 are connected integrally by welding or the like to constitute a shaft side support member. The lower ends of the pair of left and right third support members 48 are connected to both sides in the left-right direction of the support base 66, and the connection between the third support member 48 and the support base 66 is performed by fastening bolt nuts. . Thus, the shaft side support members (first to third support members 46 to 48) and the support base 66 are configured as separate bodies that can be separated. The lower end portion of the third support member 48 and the upper wall portion 66c of the support base 66 extend over the entire length of the third support member 48 and the support base 66 in the front-rear direction of the third support member 48 and the support base 66. Are in contact with each other, and both end portions in the front-rear direction are fastening points of the bolt and nut. The support base 66 is formed wider in the left-right direction than the pair of left and right third support members 48 so that the shaft side support members (first to third support members 46 to 48) can be stably supported. It is configured.

Since the support base 66 covers the outer periphery of the power steering case 63 at a distance (without contacting) with the outer periphery of the power steering case 63, the upper support member 44 supports the flange portion 49 of the lower support member 45 at the support base 66. By connecting, the upper side support member 44 is supported at the flange portion 49 of the lower side support member 45 at a position deviated from the support position of the power steering case 63.

When an external force is generated on the steering handle 15 when the steering handle 15 is rotated, the upper support member 44 is connected to the steering handle 15 via the upper shaft 41a and an intermediate member such as a bush. The external force is transmitted to the upper support member 44. The external force transmitted to the upper side support member 44 can be transmitted to the flange portion 49 of the lower side support member 45 via the support base 66, and the external force can be prevented from being transmitted to the power steering device 61. Therefore, the external force generated on the steering handle 15 can be prevented from being applied to the power steering device 61, and the external force applied to the power steering device 61 can be minimized. Moreover, since the upper side support member 44 is integrally provided with the operation tool support structure such as the lever guide 72 and the support bracket 73, the external force acting on the operation tool (the main shift lever 18 and the raising and lowering cross lever 21) Also, it can be transmitted to the flange portion 49 of the lower side support member 45 via the support base 66, and the external force can be prevented from being transmitted to the power steering device 61.

As shown in FIGS. 6 and 7, the control tool support frame 71 connects not only the control tool support configuration such as the lever guide 72 and the support bracket 73 but also the control tool support frame 71 and the support base 66. A reinforcing frame 74 is provided. The reinforcing frame 74 is disposed on the right side with respect to the steering shaft 41 in a forward inclined posture positioned on the front side toward the upper side. The lower end portion of the reinforcing frame 74 is connected to the right wall portion 66b of the support base 66, and is an integral (shaft side support member) of the first support member 46, the second support member 47, and the third support member 48. It is intended to improve the support strength. In this manner, the integral structure (shaft side support member) of the first support member 46, the second support member 47, and the third support member 48 and the support base by the part of the operation tool support frame 71 and the reinforcement frame 74. A reinforcing member that connects with the base 66 is configured by a part of the operation tool support frame 71 and the reinforcement frame 74. The reinforcing frame 74 not only connects the operation tool support frame 71 and the support base 66, but the electrical component 75 is supported at an intermediate portion thereof. As a result, in the reinforcing member constituted by a part of the operation tool support frame 71 and the reinforcing frame 74, the electrical component 75 which is a member other than the support member for supporting the steering shaft 41 and the power steering device 61 is provided. It is supported.

As shown in FIGS. 6 and 7, the lower side support member 45 not only covers the steering shaft 41, but the transmission case 81 is connected to and supported by the left side portion of the lower side support member 45. The transmission case 81 is configured by assembling divided cases that can be divided in the left-right direction. A transmission mechanism 82 (see FIG. 5) is accommodated in the transmission case 81 for shifting the output from the transmission case 7 in accordance with the transmission operation.

As shown in FIG. 5, the transmission mechanism 82 is rotatably provided with a transmission operation shaft 83 extending in the left-right direction. The base end portions of the sector gear 84 and the first arm 85 are fixed to the transmission operation shaft 83, and the transmission operation shaft 83, the sector gear 84, and the first arm 85 are integrally rotatably provided. There is. An actuator 87 (electric motor) for rotationally driving the pinion 86 meshing with the sector gear 84 is provided, and the pinion 86 is rotationally driven by the actuator 87 to rotationally drive the transmission operating shaft 83 via the sector gear 84. Is configured.

A transmission rod 93 extending rearward is connected to the tip of the first arm 85, and is configured to move the transmission rod 93 in the front-rear direction by rotation of the transmission operation shaft 83. Although not shown, the rear end portion of the transmission rod 93 is interlockingly connected to the trunnion shaft in the HST inside the transmission case 7 via an interlocking mechanism or the like. Thus, by moving the speed change rod 93 in the front-rear direction, the trunnion shaft is operated to adjust the swash plate angle of the HST to a desired angle, and the output (traveling speed) from the transmission case 7 can be continuously changed Is configured.

The sector gear 84 is formed with an arc-shaped cam groove 88, and is provided with a second arm 89 whose distal end is movably engaged in the cam groove 88. A laterally extending and rotatable horizontal shaft 90 is provided, and the proximal end of the second arm 89 and the proximal end of the third arm 91 are connected to the horizontal axis 90. The rotation of the sector gear 84 moves the tip of the second arm 89 in the cam groove 88 to rotate the horizontal shaft 90, and the third arm 91 is operated to swing. A wire 92 is connected to the tip of the third arm 91, and the throttle lever of the engine 6 is connected to the other end of the wire 92. As a result, the throttle lever is linked to be operated in conjunction with the swing operation of the third arm 91, and the engine (engine speed) from the transmission case 7 is steplessly changed to perform the engine rotation. The engine rotational speed of 6 is adjusted.

As shown in FIG. 4, the shift pedal 20 is disposed on the lower right side of the dashboard 14 in the driving operation unit 13, and a potentiometer or the like (not shown) for detecting the depression amount of the shift pedal 20 is provided. There is. Then, the actuator 87 (see FIG. 5) in the transmission mechanism 82 is rotationally driven such that the swash plate angle of the HST becomes a desired angle according to the depression amount of the transmission pedal 20. Thus, the transmission mechanism 82 shifts the output (traveling speed) from the transmission case 7 to a desired shift state according to the user's depression operation of the shift pedal 20.

As shown in FIG. 9, the lower side support member 45 has a hollow space 45a inside, so the inside of the transmission case 7 is opened to the outside using the hollow space 45a, and the power steering device 61 is used. The configuration for opening the inside of the housing to the outside is provided.

As shown in FIG. 8, a communication connection portion 100 for connecting the transmission case 7 and the lower side support member 45 in a state where the inside of the transmission case 7 and the inside of the lower side support member 45 are communicated, and the lower side support member 45 And an external opening 101 for opening the inside of the housing to the outside. The communication connection portion 100 is configured of a breather pipe for transmission that communicably connects the inside of the transmission case 7 and the inside of the lower side support member 45. A hole passing through the outer wall of the lower support member 45 is formed in the connection portion 100 a of the communication connection portion 100 to the lower support member 45, and the hole communicates with the inside of the lower support member 45. ing. The external opening portion 101 is configured of a breather pipe that communicably connects the inside and the outside of the lower side support member 45. The external opening portion 101 communicably connects the inside and the outside of the lower side supporting member 45, thereby connecting the inside of the transmission case 7 to the outside through the inside of the lower side supporting member 45, and the power, and the power The steering device 61 is also used as a breather pipe for connecting the inside of the steering device 61 to the outside through the inside of the lower side support member 45. A hole passing through the outer wall of the lower support member 45 is formed in the connection portion 101a of the outer opening 101 to the lower support member 45, and the hole communicates with the inside of the lower support member 45. ing. The outer opening portion 101 is disposed to extend upward around the steering shaft 41. An upper end portion of the outer opening portion 101 is opened to a space in which the front upper side and the left and right sides are covered by the second support member 47 of the upper side support member 44.

Since the inside of the transmission case 7 and the inside of the lower side support member 45 are connected in communication by the communication connection portion 100, as shown in FIGS. 8 and 9, the air inside the transmission case 7 is once reduced to the lower side. The hollow space 45 a of the support member 45 can be supplied. And since the hollow space 45a of the lower side support member 45 is opened to the outside by the external opening portion 101, the air supplied to the hollow space 45a of the lower side support member 45 is finally discharged to the outside. Can. Thus, the inside of the mission case 7 can be opened to the outside, the pressure inside the mission case 7 can be released to the outside, and the inside of the mission case 7 can be prevented from being high in pressure.

As shown in FIG. 9, the power steering device 61 is provided in a state where the inside of the power steering case 63 of the power steering device 61 communicates with the hollow space 45 a of the lower side support member 45. Therefore, heat and water vapor in the power steering device 61 can be temporarily supplied to the hollow space 45 a of the lower support member 45. Then, as shown in FIGS. 8 and 9, since the hollow space 45a of the lower side support member 45 is opened to the outside by the external opening portion 101, the heat supplied to the hollow space 45a of the lower side support member 45 or The water vapor can eventually be dissipated or released to the outside. As a result, the heat and water vapor inside the power steering device 61 can be dissipated or released to the outside, and the inside of the power steering device 61 will be in a high temperature state or moisture such as dew condensation water will be inside the power steering device 61. It can prevent that it accumulates.

As shown in FIG. 8, both the communication connection portion 100 and the external opening portion 101 are disposed on the right side of the lower side support member 45, and are disposed on the right side of the steering shaft 41. The connection portion 100a of the communication connection portion 100 to the lower side support member 45 and the connection portion 101a of the external opening portion 101 to the lower side support member 45 are spaced apart in the front-rear direction and the vertical direction. Incidentally, in FIG. 6 and FIG. 7, the communication connection portion 100 and the outer opening portion 101 are omitted, and the connection portion 100 a of the communication connection portion 100 to the lower side support member 45 and the outer opening portion 101 to the lower side support member 45 Only the connection point 101a is illustrated.

The connection portion 100a of the communication connection portion 100 and the connection portion 101a of the external opening portion 101 are, as shown in FIG. 8, the central portion (dotted line C in FIG. 8) of the lower side support member 45 in side view in the front and rear direction. Are arranged in a separated state across the. The connection portion 100a of the communication connection portion 100 is disposed on the rear side of the central portion of the lower side support member 45, and the connection portion 101a of the external opening portion 101 is the central portion of the lower side support member 45 and the front side thereof. Is located in Further, the connection portion 101 a of the external opening portion 101 is disposed above the connection portion 100 a of the communication connection portion 100 in the vertical direction. The connection portion 100 a of the communication connection portion 100 is disposed at the upper end portion of the lower side support member 45, and the connection portion 101 a of the external opening portion 101 is disposed at the middle portion in the vertical direction of the lower side support member 45. .

The arrangement relationship between the electric motor 62 and other devices in the power steering device 61 will be described below.
The electric motor 62 of the power steering device 61 applies a steering assist force from the lateral side orthogonal to the axial center direction of the steering shaft 41 as shown in FIGS. 6 and 7, so the lateral side of the steering shaft 41 It is arranged in the direction. As shown in FIG. 2, the electric motor 62 is disposed rearward of the engine 6 and forward of the steering shaft 41 in the front-rear direction. As described above, the electric motor 62 is disposed by effectively utilizing the space between the engine 6 and the steering shaft 41, and the engine 6, the steering shaft 41, and the power steering device are disposed in the limited space in the bonnet 10. 61 mag is arranged efficiently.

As shown in FIGS. 6 and 7, a shift case 81 is disposed on the left side of the lower side support member 45. The transmission case 81 accommodates a transmission mechanism 82 (see FIG. 5) that shifts the output from the transmission case 7 by operating the trunnion shaft of the HST. The transmission case 81 is disposed on the left side in the left-right direction with respect to the steering shaft 41, and the trunnion axis of the HST is also disposed on the left side in the left-right direction with respect to the steering shaft 41. The axes are disposed on the same side in the left-right direction with respect to the steering shaft 41. As a result, the length, the configuration, and the like of the transmission rod 93 that links the transmission case 81 and the trunnion shaft of the HST can be simplified. As shown in FIGS. 6 and 7, the electric motor 62 is also disposed on the left side of the lower support member 45, and the transmission case 81 and the electric motor 62 are arranged on the left side in the left-right direction with respect to the steering shaft 41. It arranges collectively. The electric motor 62 is disposed on the upper side relative to the transmission case 81, and efficiently disposed using the space on the upper side relative to the transmission case 81 while suppressing interference between the electric motor 62 and the transmission case 81. ing. Further, as shown in FIG. 2, in the front-rear direction, a part of the electric motor 62 and a part of the shift case 81 are disposed so as to overlap.

By arranging shift case 81 and electric motor 62 collectively on the left side in the left-right direction with respect to steering shaft 41, arrangement of electric motor 62, transmission case 81, etc. on the right side in the left-right direction with respect to steering shaft 41 There is no need to reserve space. Therefore, a large space can be secured on the right side of the steering shaft 41. As shown in FIG. 4, an oil filter 25 and an oil filler port 26 of the engine 6 are disposed on the right side in the left-right direction with respect to the steering shaft 41. Therefore, the maintenance work of the engine 6 and the like can be performed by utilizing the large space on the right side of the steering shaft 41, and the maintenance work can be simplified.

As shown in FIG. 2 and FIG. 3, a flywheel 23 is disposed at the left end of the engine 6, and a flywheel cover 24 is provided to cover the flywheel 23 from the upper side. The flywheel cover 24 is configured to cover not only the upper side of the flywheel 23 but also the rear side of the flywheel 23. The flywheel cover 24 has a portion extending in the front-rear direction at the upper portion of the flywheel 23 and a portion extending continuously downward from the rear end of the portion extending in the front-rear direction to the rear side of the flywheel 23 It is formed in an arc shape. By providing the flywheel cover 24 having such a shape, splashing of mud water and the like to the upper side is prevented.

Therefore, as shown in FIG. 2, the electric motor 62 is located above the tangent (the dotted line of S in FIG. 2) of the flywheel 23 passing through the outer peripheral portion of the flywheel 23 and the lower end of the flywheel cover 24. It is arranged. Thus, by arranging the electric motor 62, the electric motor 62 can be arranged at a position where the muddy water is prevented from being scattered by the flywheel cover 24, and the muddy water may adversely affect the electric motor 62. It can be prevented from extending. The transmission case 81 is also disposed above the tangent line (dotted line S in FIG. 2) of the flywheel 23 passing through the outer peripheral portion of the flywheel 23 and the lower end portion of the flywheel cover 24.

[Another embodiment]
(1) In the above embodiment, the electric motor 62 and the transmission case 81 are disposed on the left side of the steering shaft 41. However, the electric motor 62 and the transmission case 81 may be disposed on the right side of the steering shaft 41. In addition, the electric motor 62 and the transmission case 81 can be dispersedly disposed on the left and right sides with respect to the steering shaft 41.

(2) In the above-described embodiment, the transmission case 81 is disposed in the bonnet 10. However, the transmission case 81 may be omitted.

(3) In the above embodiment, the steering shaft 41 is divided into the three shafts of the upper side shaft 41a, the intermediate shaft 41b and the lower side shaft 41c, but the number of shafts can be changed as appropriate. For example, the steering shaft 41 can be configured by one shaft.
Also, with regard to the attitude of the steering shaft 41, for example, various attitudes such as a rearward inclined attitude positioned forward on the lower side and an upright attitude extending along the vertical direction can be applied.

(4) In the above embodiment, the communication connection portion 100 is provided to connect the transmission case 7 and the lower side support member 45 in a state where the inside of the transmission case 7 and the inside of the lower side support member 45 are communicated. The communication connection portion 100 can also be omitted.

(5) In the above embodiment, the connection portion 100a of the communication connection portion 100 to the lower side support member 45 is disposed higher than the connection portion 101a of the outer opening portion 101 to the lower side support member 45, In addition, the connection portion 101 a of the external opening portion 101 to the lower side support member 45 can be disposed above the connection portion 100 a of the communication connection portion 100 to the lower side support member 45.

(6) In the above embodiment, the connection portion 100a of the communication connection portion 100 to the lower side support member 45 and the connection portion 101a of the outer opening portion 101 to the lower side support member 45 are disposed on the right side portion of the lower side support member 45. However, for example, the connection portion 100a of the communication connection portion 100 to the lower side support member 45 and the connection portion 101a of the outer opening portion 101 to the lower side support member 45 are the left side portion and the right side portion of the lower side support member 45. It can also be distributed in Thus, the connection location 100a of the communication connection portion 100 to the lower side support member 45 and the connection location 101a of the external opening portion 101 to the lower side support member 45 are disposed at any location in the circumferential direction of the lower side support member 45. It is possible to change as appropriate.

(7) In the above embodiment, the power steering device 61 is configured to be electrically powered with the electric motor 62. However, for example, the power steering device 61 can be configured to be hydraulically equipped with a hydraulic motor. Not limited to the electric type.

(8) In the above embodiment, in the upper side support member 44, the shaft side support member consisting of the first to third support members 46 to 48 and the support base 66 are separately provided. The shaft side support member consisting of the third support members 46 to 48 and the support base 66 can be integrally configured.

(9) In the above embodiment, the connection location of the support base 66 to the flange portion 49 of the lower side support member 45 may be a position deviated from the support position of the power steering case 63. It is possible to appropriately change which part is to be the connection part.

The present invention can be applied to various working vehicles provided with a steering shaft for transmitting the steering force of a steering wheel to wheels and a power steering device for applying a steering assist force to the steering shaft.

1 Rice transplanter (work vehicle)
6 Engine 7 Mission Case 8 Front Wheel (Wheel)
DESCRIPTION OF SYMBOLS 10 Bonnet 15 Steering handle 23 Flywheel 24 Flywheel cover 41 Steering shaft 44 Upper side support member 45 Lower side support member (support member)
45a hollow space 46 first support member (shaft side support member)
47 Second support member (shaft side support member)
48 Third support member (shaft side support member)
61 Power steering device 62 electric motor 66 support base 71 support frame for operation tool 75 electrical component (member other than support member)
81 Transmission case 82 Transmission mechanism 100 Communication connection portion 100a Connection portion 101 of communication connection portion External opening portion 101a Connection portion of external opening portion C Line S indicating the central portion of the support member in a side view Tangent of the flywheel

Claims

The engine, a transmission case for transmitting the driving force from the engine, a steering shaft for transmitting the steering force of the steering wheel to the wheels, and a power steering device for applying a steering assist force to the steering shaft,
The power steering apparatus is configured to be electrically driven to apply a driving force of an electric motor to the steering shaft.
The steering shaft is supported at an upper portion of the transmission case.
In the bonnet, the engine, the steering shaft, and the power steering device are disposed;
A working vehicle, wherein the electric motor is disposed rearward of the engine and forward of the steering shaft in the front-rear direction.
The bonnet is provided with a shift case provided with a shift mechanism for shifting an output from the transmission case in accordance with a shift operation.
The transmission case is disposed at an upper portion of the transmission case.
The work vehicle according to claim 1, wherein the electric motor is disposed above the shift case.
The work vehicle according to claim 2, wherein the electric motor and the transmission case are disposed on the same side in the left-right direction with respect to the steering shaft.
A flywheel cover is provided which covers the flywheel of the engine from above.
The work according to any one of claims 1 to 3, wherein the electric motor is disposed above a tangent of the flywheel passing through an outer peripheral portion of the flywheel and a lower end portion of the flywheel cover. vehicle.
A support member supporting the steering shaft and the power steering device;
The support member supports the steering shaft in a state in which the steering shaft is positioned in a hollow space therein, and the power steering apparatus in a state in which the hollow space therein is in communication with the inside of the power steering apparatus Configured to support the
The work vehicle according to claim 1, further comprising: an external opening portion for opening the inside of the support member to the outside.
The transmission case supports the lower end of the support member and transmits a driving force to the wheels.
The work vehicle according to claim 5, further comprising: a communication connection portion connecting the transmission case and the support member in a state where the inside of the transmission case is in communication with the inside of the support member.
The work vehicle according to claim 5 or 6, wherein the connection location of the communication connection portion with respect to the support member is disposed above the connection location of the external opening portion with respect to the support member.
The connection location of the communication connection portion with respect to the support member and the connection location of the external open portion with respect to the support member are arranged in a state of being separated in the front-rear direction across the central portion of the support member in side view Item 8. The work vehicle according to any one of Items 5 to 7.
The power steering device is disposed in the middle of the steering shaft.
A lower side support member extending in an axial direction of the steering shaft in a state of surrounding the lower side portion of the steering shaft with respect to the power steering device;
And an upper support member connected to the steering handle via an intermediate member and extending in the axial direction of the steering shaft so as to surround the upper portion of the steering shaft above the power steering device.
The steering shaft and the lower side support member are supported on the top of the transmission case,
The power steering device is supported by the upper portion of the lower side support member,
2. The work vehicle according to claim 1, wherein the upper support member is supported at an upper portion of the lower support member at a position deviated from a support position of the power steering device.
The upper side support member is connected to a shaft side support member surrounding the steering shaft, and at an upper portion of the lower side support member at a position deviated from the support position of the power steering device in a state of surrounding the power steering device. Equipped with a support base,
The work vehicle according to claim 9, wherein the shaft side support member is connected to and supported by an upper portion of the support base.
A reinforcing member is provided to connect the shaft side supporting member and the support base, and the reinforcing member supports a member other than the steering shaft and the supporting member for supporting the power steering device. A work vehicle according to item 10.
The work vehicle according to claim 10, wherein a control tool support frame for supporting the control tool is connected to the shaft side support member.