JP2007038724A - Riding type work vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispose of oil leaking out from a power steering unit by using a member related to installation of the power steering unit, and to simplify an equipment structure. <P>SOLUTION: A steering wheel post 33 is raised on a transmission case 16, and the power steering unit 34 is attached to the steering wheel post 33. A storage space storing oil leaking out from the power steering unit 34 is formed on the steering wheel post 33, and a breather tank 54 adjusting pressure in the transmission case 16 and the storage space are communicated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a passenger work vehicle including a power steering unit.

The power steering unit was attached to the upper surface of the mission case (Patent Document 1).
If it does so, the upper surface of the mission case which will be arrange | positioned in the state where several apparatuses are congested may become more complicated by presence of a power steering unit.
Therefore, in order to use the upper surface of the mission case widely, there is a device in which a support case member is erected on the upper surface of the mission case and a power steering unit is attached to the support case member (Patent Document 2).

JP 2000-270627 A (paragraph number [0038], FIGS. 3 to 5) Japanese Patent Laid-Open No. 6-1253 (paragraph number [0008], FIGS. 2 and 3)

In the above configuration, in order to return the overpressure oil acting on the power steering unit to the transmission case via the relief valve, a hydraulic block is attached to the side of the power steering unit, and the power steering is extended over the hydraulic block and the transmission case. A return pipe was introduced to guide the return oil from the unit.
On the other hand, there is no description about the treatment for oil leaking from the rubbing part in the output rotating part or the like to the steering shaft in the power steering unit, and it is unclear what measures are taken.

  An object of the present invention is to perform processing of oil leaking from a power steering unit using a member related to installation of the power steering unit, thereby achieving simplification of the device configuration.

(Constitution)
A first feature of the present invention is that a support case member is erected on a transmission case, a power steering unit is attached to the support case member, and a storage space for storing oil leaking from the power steering unit is formed in the support case member The operational effects are as follows.

(Function and effect)
In other words, the present invention has been made by paying attention to the fact that the member that supports the power steering unit is a case, and it is easy to form a storage space in the support case member, and the leaking oil is stored. It is no longer necessary to install new equipment to do this.
Moreover, since the storage space is provided in the support case member, it is not necessary to take a measure to install a power steering unit in the transmission case in order to return the leaking oil directly to the transmission case. Can be arranged. As a result, the space above the mission case can be effectively used, and the devices can be easily placed around the mission case where the devices are congested.

(Constitution)
The second feature of the present invention resides in that the storage space and the blazer mechanism for adjusting the pressure in the mission case are communicated with each other, and the operation and effects thereof are as follows.

(Function and effect)
According to the second feature of the present invention, since the oil is returned to the transmission case via the blazer mechanism, it is not necessary to provide a receiving mechanism for receiving the leaked oil in the transmission case itself. In other words, it is not necessary to modify the mission case that is an important functional device and has a robust structure to provide a new receiving mechanism, and the receiving mechanism is simpler than the mission case. It can be applied to the blazer mechanism.

(Constitution)
A third characteristic configuration of the present invention is that the support case member is made of a casting, and the operation and effect thereof are as follows.

(Function and effect)
According to the 3rd characteristic of this invention, the freedom degree of a shape expanded by manufacturing with a casting. Therefore, it is possible to reduce the size with a free shape setting, and even if the support case member is accommodated in the engine bonnet by a space-saving structure, the arrangement of the equipment in the engine bonnet is facilitated. By arranging ribs or the like in necessary portions to improve the mechanical strength, weight reduction can be achieved, and the heat capacity is reduced by the weight reduction, so that the heat balance in the hood can be improved.
On the other hand, it is possible to reduce the number of parts such as a connecting member by the casting structure, and there is an effect that an adjustment process such as alignment of bolt holes required when connecting the devices with the connecting member can be omitted.

(Constitution)
According to a fourth aspect of the present invention, the support case member is a handle post, and the handle post and a power steering unit supported by the handle post are integrated and can be attached to the transmission case. The operational effects are as follows.

(Function and effect)
According to the fourth feature of the present invention, since the handle post and the power steering unit can be assembled together, it is possible to adopt a manufacturing process in which these are assembled in advance and the assembly is attached to the mission, thereby improving the assemblability. To do.
In addition, since it can be assembled in advance in this way, the manufacturing process can be shortened when variations are made between the power steering specification using the power steering unit and the manual specification not using the power steering unit.

(Constitution)
The fifth feature of the present invention resides in that an engine support portion is provided on the handle post, and its operation and effect are as follows.

(Function and effect)
According to the fifth characteristic configuration of the present invention, it is not necessary to provide another dedicated support portion as the engine support portion in place of the portion of the handle post, and the device configuration can be simplified.

(Constitution)
The sixth characteristic configuration of the present invention is that an operating member mounting portion is provided on the handle post, and its operation and effect are as follows.

(Function and effect)
According to the sixth aspect of the present invention, it is not necessary to provide another dedicated support portion as a mounting portion for the operation member in place of the portion that the handle post handles, and the device configuration can be simplified.

(Constitution)
A seventh characteristic configuration of the present invention is that a bracket having a mounting portion for mounting a driving operation tool is detachably provided on the handle post, and the operation and effect thereof are as follows.

(Function and effect)
According to the seventh feature of the present invention, the operation tools can be collectively attached and detached via the bracket, and the manufacturing process for preinstalling the operation tools on the bracket can be taken. It becomes easy to do.

  As shown in FIG. 1, a driving unit 3 is provided on a machine body supported by a front wheel 1 and a rear wheel 2, and a seedling planting device 6 is driven up and down via a link mechanism 4 and a hydraulic cylinder 5 at the rear part of the machine body. A riding type rice transplanter is supported freely.

  As shown in FIGS. 1 and 2, the seedling planting device 6 is configured in a four-row planting type, and is provided on two transmission cases 21, on the right and left lateral sides of the rear portion of the transmission case 21. A pair of planting arms 23, a grounding float 24, a seedling platform 25 on which seedlings are placed, and the like are provided. As a result, the planting case 22 is rotationally driven as the seedling platform 25 is driven back and forth to the left and right, and the planting arm 23 alternately takes out seedlings from the lower part of the seedling platform 25 and puts them on the rice field. Plant.

  As shown in FIGS. 1 and 3, a transmission case 16 is provided below the floor 7, and a hydrostatic continuously variable transmission 31 is connected to the left lateral side of the front portion of the transmission case 16. The engine 10 is supported on a front frame 19 connected to the engine 16. The power of the engine 10 is transmitted to the input pulley 31a of the hydrostatic continuously variable transmission 31 via the transmission belt 32, and the power of the hydrostatic continuously variable transmission 31 is installed in the transmission case 16 (see FIG. (Not shown) is transmitted to the front wheel 1, and the power of the auxiliary transmission is transmitted to the rear wheel 2 via right and left side clutches (not shown) housed in the transmission case 16. .

  As shown in FIGS. 1, 2, and 3, a steering wheel 11 for steering the front wheel 1 is provided on the upper part of the bonnet 9. An accelerator lever 15 for operating the accelerator portion of the steering wheel 11 is provided, and a left side portion of the steering wheel 11 is provided with a main transmission lever 13 and an auxiliary transmission lever 14 for operating the hydrostatic continuously variable transmission 31. . These three levers 15, 13, and 14 are attached to an operation tool bracket 17 having a channel shape to be described later. Here, these three levers 15, 13, and 14 are collectively referred to as a driving operation tool.

  As shown in FIGS. 1, 2, and 3, an operation arm 20 having a reverse U-shape in front view is swingably supported around the horizontal axis P <b> 1 of the front frame 19, and the operation arm 20 stands up upward. It is configured to be swingable over the position and the working position that protrudes forward from the front of the machine body. When the operation arm 20 is operated to the work position that is forwardly moved from the front of the machine body, the front wheel 1 and the steering wheel 11 are held in the straight traveling position, and the operation arm 20 is raised upward as shown in FIGS. When operated to the retracted position, the holding of the front wheel 1 and the steering wheel 11 is released.

[Power steering specification]
Next, a steering operation structure that employs a power steering device will be described. As shown in FIGS. 5 and 6, a mounting seat 16A is formed on the upper surface of the mission case 16, and a cono-shaped bracket formed on the lower end portion of the lower handle post 33 as a support frame with respect to the mounting seat 16A. It is configured to be detachable by covering the portion 33A. A cylindrical portion 33B extends upward from the conical bracket portion 33A, and an upper end flange portion 33C for fitting and holding the lower end flange portion 34A of the power steering unit 34 is formed at the upper end portion of the cylindrical portion 33B. The lower handle post 33 is made of a casting.

Thus, the power steering unit 34 is configured to be detachable from the upper end flange portion 33C of the lower handle post 33.
An upper handle post 35 is erected upward from the upper surface of the power steering unit 34, and the steering wheel 11 is attached to the upper end of the handle shaft extending above the upper handle post 35.

  Next, the attachment structure of the main transmission lever 13, the auxiliary transmission lever 14, and the accelerator lever 15 will be described. As shown in FIGS. 4 to 7, a channel-shaped operating tool bracket 17 is provided so as to surround the front side and the left and right side surfaces of the power steering unit 34. The mounting structure of the operating tool bracket 17 is as follows. It is like this. The operation tool bracket 17 is fixed to the lever guide 37 by welding its upper end to the lever guide 37 from below, and the lower end portions of the left and right side plate portions 17A and 17B are connected to the upper end flange portion 33C of the lower handle post 33. The bolts 64 are fixed to the bolts 64 and fixed.

  As shown in FIGS. 6 and 7, a steering shaft 52 is erected on the upper end surface of the power steering unit 34, and an upper handle post 35 is placed on the steering shaft 52 and attached to the lower end of the handle post 35. The fixed flange-shaped bracket 35A is attached to the upper end surface of the power steering unit 34 with bolts 62 positioned at the front and rear, and the upper handle post 35 is attached and fixed to the power steering unit 34. The front end portion of the flange-like bracket 35A is bent upward and raised, and this raised portion is brought into contact with the front plate portion 17C of the operation tool bracket 17 from the rear side. The bracket 17 is connected and fixed.

  A fan-shaped plate 38 is pivotally supported on the outer side of the left-side plate portion 17A of the operation tool bracket 17 so as to swing back and forth along the left-side plate portion 17A, and a pair of cut-and-raised plate portions are provided on the fan-shaped plate 38. 38A and 38A are provided, and the bent lower end rod-like portion of the main transmission lever rod 13A is inserted into the insertion hole of the pair of raising and lowering plate portions 38A and 38A to support the main transmission lever 13 so as to be swingable left and right. It is. The main speed change lever 13 is swingable to the left and right around the axis center of the main speed change lever rod 13A in the longitudinal direction of the machine body and biased to one side by a spring 13a. It can swing back and forth around the horizontal axis.

  A serrated engaging portion 38B is formed on the outer peripheral surface of the sector plate 38, and a leaf spring is attached to the lever guide 37 in a cantilever manner, and a cam follower that engages the engaging portion 38B at the tip of the leaf spring. 39 is provided, and the engaging portion 38B and the cam follower 39 described above constitute a detent mechanism for positioning the shift position of the main shift lever 13.

  The linkage structure from the fan plate 38 to the hydrostatic continuously variable transmission 31 will be described. As shown in FIGS. 4 and 5, the drive arm that integrally swings around the fan plate 38 and the horizontal axis X described above. 40, a bell crank-shaped relay arm 41 supported by a lateral support boss 33D provided on the cylindrical portion 33B of the lower handle post 33 so as to be swingable about a horizontal axis, a drive arm 40 and a relay arm 41, Are connected to the other end side of the relay arm 41, and the tip of the drive rod 43 is connected to the trunnion shaft of the hydrostatic continuously variable transmission 31. . Here, the lateral support boss 33 </ b> D is referred to as an attachment portion that supports the relay arm 41 as an operation member.

  Next, the auxiliary transmission operation structure will be described. As shown in FIGS. 4 and 5, the rotary drive shaft 14 </ b> A is supported in a state of being positioned in front of the power steering unit 34 over the left and right side plate portions 17 </ b> A and 17 </ b> B of the operation tool bracket 17, and the operation tool bracket The auxiliary transmission lever 14 is fixedly attached to one end of the rotational drive shaft 14A protruding from the left and right side plate portions 17A, 17B. An interlocking bracket 44 is attached to the other end of the rotary drive shaft 14A so as to be swingable integrally, and a linkage rod 46 is attached to the interlocking bracket 44 via a stroke absorbing spring 45, and a sub-transmission device (not shown) is operated to change speed. It is constituted as follows.

An accelerator lever 15 is provided on the operating tool bracket 17 via a support shaft 47 above the interlocking metal fitting 44 and is operably supported via a positioning spring friction holding mechanism 48.
A channel-shaped bracket 49 is attached to the operation tool bracket 17 sideways in the state of being close to the interlocking bracket 44 near the upper end flange portion 33C of the lower handle post 33, and the choke lever 50 is supported by the channel-shaped bracket 49. It is. An operation tool 51 for a recoil starter is provided below the choke lever 50.
As described above, the main transmission lever 13, the auxiliary transmission lever 14 and the accelerator lever 15 are attached to the operation tool bracket 17 and are configured as a unit with the operation tool bracket 17.

  Next, processing of oil leaking from the power steering unit 34 will be described. As shown in FIGS. 5 and 8, the drive portion 34 </ b> B extends from the lower surface of the power steering unit 34 into the lower handle post 33 and is linked to the steering shaft 52. A space a for accommodating the drive portion 34B is formed in the lower handle post 33, and an oil seal 53 is attached to a lower end portion of the space a, and the space a is passed through the oil from the steering shaft 52. It is configured as a storage space that prevents leakage.

  As shown in FIG. 5, a take-out boss 33E extends laterally from the lower handle post 33, and a blazer tank 54 as a blazer mechanism for performing a breathing action on the mission case 16 is disposed below the take-out boss 33E. . A communication pipe 55 is disposed between the take-out boss 33 </ b> E and the blazer tank 54, and drain oil leaking from the power steering unit 34 is guided to the blazer tank 54. By utilizing the blazer tank 54 in this way, a dedicated container for collecting drain oil is not required.

  The arrangement structure around the engine 10 will be described. As shown in FIGS. 3 and 4, the support bracket 56 extends forward from the front surface of the operation tool bracket 17, and the rear end portion of the fuel tank 57 is supported by the support bracket 56. The engine 10 is disposed below the fuel tank 57, and the engine 10 is supported via a vibration preventing rubber mechanism 58 disposed at four points.

  An anti-vibration rubber mechanism 58 disposed on the left rear side is provided with an anti-vibration rubber 58A and a bracket 58B for receiving the anti-vibration rubber 58A below the engine-side bracket 72 extended from the cylinder head 10A of the engine 10. The side handle post 33 is supported by a mounting boss 71 extending from the cono-shaped bracket portion 33A via a bolt 71A. As a result, the lower handle post 33 can be used as a support portion of the vibration preventing rubber mechanism 58.

  The engine 10 has a cylinder tilted rearward, and the cylinder head 10A portion is disposed in the vicinity of the lower handle post 33. The disposed state is a transmission case 31 and a power steering unit disposed above the mission case 31. The cylinder head 10 </ b> A is inserted into the space b on the front side of the lower handle post 33 at a portion overlapping with 34 in a plan view. As a result, the engine 10 can be disposed near the driver's seat 8 and the arrangement configuration in the engine bonnet can be made compact.

  As shown in FIGS. 5 and 6, a steering shaft 52 extends upward from the power steering unit 34, and the steering wheel 11 is attached to the extending end. A steering shaft 52 extending downward from the power steering unit 34 penetrates the mission case 31 and protrudes downward. Although not shown in the lower end portion thereof, a pitman arm as a steering mechanism that steers and drives the traveling wheels. A reduction gear mechanism for transmitting reduction power to 59 is attached.

In the configuration as described above, the steering shaft to which the reduction gear mechanism is attached as compared with the upper distance L1 between the upper end of the steering shaft 52 to which the steering wheel 11 is attached in the direction along the upper and lower steering shafts 52 and the power steering unit 34. A lower distance L2 between the lower end of 52 and the power steering unit 34 is long.
With such a configuration, the power steering unit 34 can be arranged in the upper space in the engine bonnet 9 having a relatively large space, and a sufficient space is secured in the middle part in the engine bonnet 9 so that the equipment can be freely arranged. The degree can be increased.

[Manual steering specification]
Next, a manual specification model that does not use the power steering unit 34 will be described. Here, only differences from the power steering type will be mainly described. As shown in FIGS. 9 and 10, the bracket 60 in which the left and right side plate portions 60A and 60B and the bottom plate portion 60C are integrally formed in a channel shape is adopted as having the same function as the operation tool bracket 17. The operation tool bracket 60 is attached and fixed to the lever guide 37 of the engine bonnet 9.

A support shaft 61 is installed across the left and right side plate portions 60A and 60B of the operating tool bracket 60, and the fan-shaped plate 38 and the accelerator are provided at both ends of the support shaft 61 protruding outward from the left and right side plate portions 60A and 60B. The lever 15 is supported in an idle manner.
In the fan-shaped plate 38, the cut-and-raised portions 38a and 38a are provided opposite to each other, and the bent base end portion of the main transmission lever 13 is inserted into and supported by the cut-and-raised portions 38a and 38a. This configuration is the same as in the power steering specification. Further, the connecting rod 42 is directly connected to the fan-shaped plate 38. Linking to the trunnion shaft of the hydrostatic continuously variable transmission 31 from the linkage rod 42 via the relay arm 41 is the same as in the power steering specification.

In the case where the rotational drive shaft 65 is installed over the left and right side plate portions 60A and 60B below the support shaft 61, and the power drive specification is provided at both ends of the rotation drive shaft 65 protruding outward from the left and right side plate portions 60A and 60B. Similarly, the auxiliary transmission lever 14 and the interlocking fitting 44 are attached so as to be able to operate integrally.
The choke lever 50 and the bracket 68 are attached to the lower end of the right side plate portion 60B of the operation tool bracket 60 in the same manner as in the case of the power steering specification. An operation tool 51 for a recoil starter is provided below the choke lever 50.

  In the power steering specification, the power steering unit 34 is sandwiched between the upper handle post 35 and the lower handle post 33, but in the manual specification, a handle post 70 in which upper and lower handle posts are integrally formed is introduced. A cono-shaped bracket 70A is formed at the lower end of the handle post 70 as in the case of the power steering specification, and the cono-shaped bracket 70A is attached to the mounting seat 16A of the transmission case 16. Therefore, the attachment structure of the handle post 70 to the transmission case 16 at this portion is the same.

[Another embodiment]
(1) Although the handle post 33 is used as the support case member, a dedicated support case member may be provided.
(2) The blazer mechanism is not necessarily a container, and may be a pipe-like one standing from a mission case.
(3) The support case member may be composed of a steel pipe.
(4) The concept of a driving operation tool includes an operation tool that obtains an ultra-low speed or a turning operation.
(5) Agricultural tractors and the like are included as a passenger work vehicle in addition to a rice transplanter.

Overall side view of riding rice transplanter Overall plan view of riding rice transplanter Side view showing the equipment configuration inside the power steering engine bonnet 3 is an enlarged view of the main part in FIG. Rear view in FIG. Side view showing the positional relationship between the power steering unit, handle post, and steering mechanism Exploded side view showing bracket mounting structure for operation tool A longitudinal side view showing a space for storing oil leaking from the power steering unit in the handle post Side view showing handle post etc. in manual specification Rear view in FIG.

Explanation of symbols

13, 14, 15 Driving operation tool 16 Mission case 17 Operating tool bracket 33 Support case member 33D, 33E Mounting portion of operation member 34 Power steering unit 54 Blazer mechanism 58 Vibration prevention rubber mechanism

Claims (7)

  A riding type work vehicle in which a support case member is erected on a transmission case, a power steering unit is attached to the support case member, and a storage space for storing oil leaking from the power steering unit is formed in the support case member.   The riding work vehicle according to claim 1, wherein a blazer mechanism for adjusting a pressure in the transmission case and the storage space are communicated with each other.   The riding work vehicle according to claim 1 or 2, wherein the support case member is made of a casting.   The riding work vehicle according to claim 3, wherein the support case member is a handle post, and the handle post and a power steering unit supported by the handle post are integrally attached to the transmission case.   The riding work vehicle according to claim 4, wherein an engine support portion is provided on the handle post.   The riding work vehicle according to claim 4 or 5, wherein a mounting portion for an operation member is provided on the handle post.   The riding type work vehicle according to any one of claims 1 to 6, wherein the handle post is detachably provided with a bracket having a mounting portion for mounting a driving operation tool.

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