JP2004114751A - Passenger work vehicle - Google Patents

Abstract

A work vehicle in which a drive force from an engine is branched and transmitted by a transmission case to a pair of left and right hydrostatic continuously variable transmissions for traveling and a hydraulically operable work clutch is provided inside the transmission case. In addition, the clutch valve and the hydraulic circuit can be easily obtained and easily obtained.
A clutch valve (76) is provided on a support (93) extending above a case body (30a) from a rear wall (90) detachably attached to a case body (30a) of a transmission case (30). The clutch valve 76 is supplied with lubricating oil as hydraulic oil from inside the transmission case 30 by an oil supply passage 74 provided inside the rear wall portion 90.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is configured to transmit the driving force from the engine to a pair of left and right traveling hydrostatic continuously variable transmissions by a transmission case and to a working device, and to transmit the pair of left and right traveling hydrostatic transmissions. The present invention relates to a riding type work vehicle in which a continuously variable transmission is distributed and connected to both lateral sides of the transmission case, and a hydraulically operable work clutch for turning on and off transmission to the work device is provided inside the transmission case.
[0002]
[Prior art]
In some of the above-mentioned work vehicles, the operation clutch is switched by using the lubricating oil inside the transmission case as a working oil. In this type, a clutch valve is conventionally mounted on a rear wall of a transmission case as shown in Patent Document 1, and the clutch valve is switched.
[0003]
[Patent Document 1]
JP-A-2000-270652 (paragraph number [0043], FIG. 10)
[0004]
[Problems to be solved by the invention]
Conventionally, a clutch valve has entered the interior of a vehicle body, making it difficult to reach or secure a working space, making it difficult to perform work such as inspection. In order to operate the clutch valve with the working lever in the driving section, the interlocking mechanism between the clutch valve and the working lever must have a long interlocking distance, or it must be a complicated one that requires many components such as links. I tended to be.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a riding type work vehicle that is easy to perform inspection work and easy to obtain in terms of operation system and oil passage in spite of being able to operate a clutch using lubricating oil in a transmission case as hydraulic oil. Is to do.
[0006]
[Means for Solving the Problems]
The configuration, operation and effect of the invention according to claim 1 are as follows.
[0007]
〔Constitution〕
The pair of left and right traveling hydrostatic continuously variable transmissions is configured to be transmitted to a pair of left and right traveling hydrostatic continuously variable transmissions by a transmission case and to a working device by a transmission case. A transmission type work vehicle having a hydraulically operable work clutch for turning on and off the transmission to the working device, which is provided inside the transmission case.
The transmission case includes a support portion extending upward from the case body from a rear wall portion that is detachable from the case body of the transmission case, and a clutch valve for operating the work clutch is provided on the support portion, and the transmission case is provided. And an oil supply passage connecting the clutch valve to the inside of the rear case and supplying lubricating oil in the transmission case to the clutch valve is provided inside the rear wall portion.
[0008]
[Action]
The lubricating oil in the transmission case is supplied to the clutch valve by the oil supply path, and the clutch valve supplies the lubricating oil from the oil supply path to the work clutch. Switching operation is possible.
[0009]
It has a support extending from the rear wall of the transmission case to the top of the case body, and a clutch valve is provided on this support, so that the clutch valve can be placed near the upper part of the vehicle body, such as below the driver's seat. . Since the oil supply passage connecting the inside of the transmission case and the clutch valve is provided inside the rear wall, the hydraulic circuit can be configured such that the oil supply passage is not exposed to the outside of the transmission case.
[0010]
〔effect〕
Therefore, while using the lubricating oil in the transmission case as hydraulic oil, it is possible to operate the work clutch while simplifying the structure and reducing the weight so that no special hydraulic oil or oil tank is required. The clutch valve is located near the upper part of the vehicle body so that work such as inspection can be easily performed from above the vehicle body, and the clutch valve can be linked to the working lever of the operating unit by a compact and simple linkage mechanism. The hydraulic circuit is configured such that the oil supply path is not exposed outside the transmission case, and simplification can be achieved from this aspect as well.
[0011]
The configuration, operation and effect of the invention according to claim 2 are as follows.
[0012]
〔Constitution〕
In the configuration of the invention according to claim 1, the hydraulic pump of the oil supply passage is disposed in a pump chamber of the rear wall portion and is integrally rotatably mounted on an input shaft supported over the case body and the rear wall portion. A bearing supported by the rear wall and rotatably supporting the input shaft is disposed closer to the front wall surface than the hydraulic pump.
[0013]
[Action]
The input shaft is supported by the rear wall with the front end projecting rearward from the rear wall. Accordingly, when the bearing for the input shaft is disposed on the back side of the rear wall portion with respect to the hydraulic pump and attached to the rear wall portion, the hydraulic pump is located at a position closer to the distal end than the portion of the input shaft supported by the bearing. And is driven by this part. Then, since the center of the input shaft is liable to be displaced, the seal members located on both lateral sides of the hydraulic pump are liable to be worn due to the dislocation of the input shaft. On the other hand, in the invention according to claim 2, since the bearing is disposed on the rear wall surface side of the hydraulic pump and attached to the rear wall portion, the misalignment on the input shaft tip side is on both sides of the hydraulic pump. It is less likely to affect the sealing material. Thus, the hydraulic pump can be driven by the input shaft while the abrasion of the seal member caused by the centering of the input shaft at the tip end side is unlikely to occur.
[0014]
〔effect〕
Therefore, although the hydraulic pump is driven by the input shaft in the pump chamber at the rear wall, the seal material of the hydraulic pump has high durability so that it is hardly worn out.
[0015]
The configuration, operation and effect of the invention according to claim 3 are as follows.
[0016]
〔Constitution〕
In the structure of the invention according to claim 1 or 2, a strainer acting on lubricating oil sucked into the oil supply passage and a cover for covering an upper portion of the strainer are provided inside the transmission case.
[0017]
[Action]
In the transmission case, dust such as metal powder is likely to be generated due to operation of the work clutch and the like. Even if the dust sinks, the dust sinks on the cover, and the dust easily mixes with the lubricating oil sucked through the strainer. This makes it difficult for dust generated in the transmission case to be sent to the valve or the actuator.
[0018]
〔effect〕
Therefore, although the lubricating oil in the transmission case is used for the hydraulic oil, the reliability is high so that malfunctions of valves and actuators caused by dust generated in the transmission case are unlikely to occur.
[0019]
The configuration, operation and effect of the invention according to claim 4 are as follows.
[0020]
〔Constitution〕
The structure according to any one of claims 1 to 3, wherein an oil filter is mounted on an upper surface side of the support portion, and a driver's seat is lowered near an upper portion of the transmission case; It is mounted so as to be able to rotate and switch to a higher management position.
[0021]
[Action]
When the driver's seat is in the down position, the driver's seat is located near the upper part of the transmission case to cover the oil filter. By opening the upper part of the case, it is easier to perform operations such as checking or replacing the oil filter from above.
[0022]
〔effect〕
Therefore, the oil filter can be covered at the time of work or the like, and the upper part of the oil filter can be opened at the time of inspection or the like.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIG. 1 and FIG. 2, a prime mover having an engine 3 which is self-propelled by a front wheel 1 composed of a pair of left and right caster wheels and a pair of left and right drivable rear wheels 2 and is located at a rear end of the vehicle body, A driving section having a driving seat 4 located on the front side of the driving section, between the front and rear wheels of a body frame 10 of a self-propelled body equipped with a fall protection frame 5 located near the rear side of the driving seat 4, A lawn mower 7 is connected via a link mechanism 6 to form a riding lawn mower.
[0024]
In this lawn mower, a single-acting lift cylinder 8 located below a driver's seat 4 swings a link mechanism 6 up and down with respect to a vehicle body frame 10 to move a lawn mower 7 forward and backward of a mower deck 7a. When the gauge wheel 7b located on the side is raised and lowered to a lowering work position where the gauge wheel 7b is in contact with the ground, and the gauge wheel 7b is raised and lowered from the ground, and the lawn mower 7 is moved to a lowering work position, the vehicle is run. The lawn mowing device 7 cuts the lawn by a blade (not shown) which is rotated around a vertical axis of the vehicle body by a driving force from the engine 3 at a plurality of locations in the mower deck 7a arranged in the lateral direction of the vehicle body. Is discharged from the discharge port 7c at one lateral end of the mower deck 7a, and is configured in detail as follows.
[0025]
As shown in FIGS. 3 and 4, the vehicle body frame 10 includes a pair of left and right vehicle body front-facing vehicle body main frames 11, a front frame 12 connected across the front end portions of the left and right vehicle body main frames 11, A traveling and working transmission 13 connected between the intermediate portions of the frame 11, a rear frame 14 connected between the rear ends of the left and right vehicle body main frames 11, a front frame 12 and the transmission 13. The vehicle is provided with a connection frame 15 that connects the left and right body main frames 11 therebetween. Each of the left and right vehicle main frames 11 has a front end connected to the front connection frame 12 and a rear end connected to the transmission 13, and a front end connected to the transmission 13. The rear body frame 17 is connected to the rear connection frame 14 at the rear end.
[0026]
The left and right front wheels 1 are supported by the free ends of a single front wheel support rod 18 having an intermediate portion rotatably connected to a front wheel support portion 12a of the front frame 12 and having an intermediate portion rotatably around a longitudinal axis of the vehicle. Let me do it. The left and right rear wheels 2 are supported by a rear axle 2 a provided in the transmission 13. The link mechanism 6 is supported across the front body frame portions 16 of the left and right body main frames 11. The driver's seat 4 is supported by a seat support frame 19 as shown in FIG. 4 that is connected across the rear end sides of the left and right front vehicle body frame portions 16. The engine 3 is supported by an engine mounting frame 3a as shown in FIG. 3, which is connected to the rear body frame portion 17 of the vehicle body main frame 11 and the rear connection frame 14.
[0027]
As shown in FIG. 5, the fall protection frame 5 includes a lower frame 5a fixed to both lateral sides of the body frame 10, a standing use posture over the upper end portions of the pair of left and right lower frames 5a, The upper frame 5b is supported so as to be freely switchable to the posture, and is connected by a connecting frame 5c connecting the intermediate portions of the left and right lower frames 5a.
[0028]
As shown in FIGS. 6 and 7, the transmission device 13 includes a transmission case 30 in which an input shaft 31 protrudes rearward in the vehicle body at an upper end side, and a casing 41 on both lateral side portions on the upper end side of the transmission case 30. A continuously variable transmission 40 having one lateral side connected thereto, an upper end side is connected to a lateral side portion of the left continuously variable transmission 40 on the lateral side of the vehicle body, and the left rear axle 2a is rotatable at a lower end side. A deceleration transmission case 50 that is supported, a deceleration transmission case that has an upper end connected to a lateral side portion of the right continuously variable transmission 40 that is laterally outside the vehicle body, and that rotatably supports the right rear axle 2a at the lower end. 50 is provided.
[0029]
As shown in FIG. 7, the input shaft 31 of the transmission case 30 is linked to the output shaft 3a of the engine 3 by a rotating shaft 21. Inside the transmission case 30, there is provided one tubular-shaft traveling branch transmission shaft 32, which is lateral to the vehicle body, and a gear mechanism 33 that transmits power to the traveling branch transmission shaft 32 from the input shaft 31. It is. At the lower end side of the transmission case 30, a work output shaft 34 facing the vehicle front and rear is supported, and a work transmission mechanism 35 using a gear for transmitting power from the input shaft 31 to the work output shaft 34 is connected to the transmission case 30. It is provided inside. The working output shaft 34 is linked with the input shaft 7d located on the upper surface side of the mower deck 7a of the lawn mower 7 by the rotating shaft 22 as shown in FIG.
[0030]
As shown in FIGS. 6 and 7, each of the left and right continuously variable transmissions 40 has a casing main body 41 a in which a lateral side inside the vehicle body is connected to a lateral side of the transmission case 30 and a casing main body 41 a. A variable-capacity axial plunger pump 43 and a constant-capacity axial plunger motor 44 are provided inside the casing 41 comprising a port block 42 connected to a lateral side portion of the vehicle body 41a on the outer side of the vehicle body. At the same time, the pump 43 and the ports of the motor 44 are connected to each other by an oil passage (not shown) provided inside the port block 42. That is, a hydrostatic continuously variable transmission is configured so that the motor 44 is driven by pressure oil from the pump 43. Thus, the continuously variable transmission 40 on either side converts the driving force of the input shaft 45, which is the input shaft of the pump 43, into the driving force on the forward side by changing the swash plate angle of the pump 43, and A forward transmission state such that the speed is changed steplessly and output from an output shaft 46 which is an output shaft of the motor 44, or the driving force of the input shaft 45 is converted into a driving force on the reverse side, and The output is changed from the output shaft 46 to a reverse transmission state, and the output from the output shaft 46 is stopped.
The input shaft 45 of the continuously variable transmission 40 on the left is connected to one end of the traveling branch transmission shaft 32 of the transmission case 30, and the input shaft 45 of the continuously variable transmission 40 on the right is The other ends are connected so as to rotate integrally by spline engagement.
[0031]
As shown in FIG. 8, both the deceleration transmission case 50 for the left rear wheel and the deceleration transmission case 50 for the right rear wheel are located on the lower side of the port block 42 of the continuously variable transmission 40 on the laterally outer side of the vehicle body. A transmission case main body 50b having an opening 50a closed by a port block 42, with an end on the side of the opening abutting on the side surface and being tightened and connected by a plurality of connection bolts; It is constituted by. The output gear 46 of the continuously variable transmission 40 is provided with the input gear 51 provided in the inside of the deceleration transmission case 50 for the left rear wheel and the inside of the deceleration transmission case 50 for the right rear wheel. And a gear-based reduction transmission mechanism 53 comprising an output gear 52 rotatably and integrally rotatably connected to the rear axle 2a by spline engagement with the input gear 51 while meshing with the input gear 51. is there. The transmission ratio between the input gear 51 and the output gear 52 of the reduction transmission mechanism 53 is the reduction transmission ratio.
[0032]
Thus, the transmission 13 inputs the driving force transmitted from the output shaft 3 a of the engine 3 by the rotating shaft 21 to the transmission case 30 via the input shaft 31, and the transmission mechanism 30 uses the gear mechanism 33 and the transmission mechanism 35 of the transmission case 30. Divide for traveling and for work. The driving force branched for traveling is branched by the traveling branch transmission shaft 32 of the transmission case 30 into the input shaft 45 of the continuously variable transmission 40 on the left side and the input shaft 45 of the continuously variable transmission 40 on the right side. The driving force transmitted and transmitted to the continuously variable transmission 40 on the left side is converted by the continuously variable transmission 40 into driving force on the forward side or on the reverse side, and is continuously converted on both the forward side and the reverse side. The signal is input from the output shaft 46 to the left deceleration transmission case 50, decelerated by the deceleration transmission mechanism 53 of the deceleration transmission case 50, and transmitted to the left rear axle 2a to be transmitted to the left rear wheel 2 and to the right continuously variable transmission. The driving force transmitted to the device 40 is converted by the continuously variable transmission 40 into driving force on the forward side or on the reverse side, and is continuously converted on both the forward side and the reverse side, so that the right side of the output shaft 46 is transmitted to the deceleration transmission. Case Type 0 is transmitted to the right rear wheel 2 by transmitting to the right rear axle 2a is decelerated by the reduction gear mechanism 53 of the speed reduction transmission case 50. The driving force branched for work in the transmission case 30 is output from the transmission case 30 to the vehicle body front side by the work output shaft 34 and transmitted to the rotating shaft 22 to be transmitted to the lawn mower 7.
[0033]
In any of the left and right continuously variable transmissions 40, the swash plate angle of the pump 43 is changed by a swing operation of a shift operation part 47 located outside the upper end of the casing 41 as shown in FIG. The shift operation part 47 of the continuously variable transmission 40 on the left is provided with a continuously variable transmission on the right side of the left steering lever 23a of the pair of left and right steering levers 23a and 23b as shown in FIG. The shift operation section 47 of the transmission 40 is linked to a right steering lever 23b of the pair of left and right steering levers 23a and 23b via a link mechanism (not shown).
In other words, the pair of left and right steering levers 23a and 23b are individually rocked in the vehicle longitudinal direction to shift the pair of left and right continuously variable transmissions 40 separately, so that the left and right rear wheels 2 are the same on the forward and reverse sides. The driving direction of the vehicle body is changed by driving the vehicle body straight forward or straight backward by driving at a driving speed of, and by driving the left and right rear wheels 2 at different driving speeds or at different driving directions.
[0034]
As shown in FIG. 7, the work transmission mechanism 35 located inside the transmission case 30 is provided with a work clutch 36, and the work clutch 36 transmits the power from the input shaft 31 to the work output shaft 34. Is switched between the on state and the off state, thereby driving the lawn mowing device 7 on and off.
[0035]
As shown in FIG. 8, a traveling brake 60 having a plurality of brake disks 61 attached to the output shaft 46 of the continuously variable transmission 40 is provided in each of the left and right deceleration transmission cases 50.
Each of the left and right running brakes 60 includes, in addition to the brake disk 61, a plurality of friction plates 62 supported by the support portion 54 of the reduction transmission case 50, an operation ring 63, and the like. Each of the brake discs 61 slides with respect to the input gear 51 of the output shaft 46 and rotates integrally with the output gear 46 by the action of spline teeth provided in a mounting hole that is fitted to the output shaft 46. Is engaged. Each of the friction plates 62 is engaged with the support portion 54 so as to slide in the direction along the output shaft 46 and not to rotate relatively.
[0036]
That is, when the operation lever 64 located outside the deceleration transmission case 50 is swingably operated around the axis of the rotation support shaft 64a, the operation cam attached to the end of the rotation support shaft 64a so as to be integrally rotatable. 65 rotates the operation ring 63 by the set rotation angle. Then, the operation ring 63 is slid toward the brake disk 61 by the action of the cam ball 66, and the brake disk 61 and the friction plate 62 are pressed against the support ring 67 fixed to the support portion 54, and the traveling brake 60 is operated. Applies a frictional braking force to the brake disc 61 and applies the frictional braking force to the rear axle 2a via the input gear 51 and the output gear 52, so that a brake is applied so as to apply a friction brake to the rear wheel 2. become.
[0037]
In any of the left and right continuously variable transmissions 40, the capacity is set so that the capacity of each plunger of the pump 43 is smaller than the capacity of each plunger of the motor 44. That is, on either the forward side or the reverse side, the amount of oil discharged per one rotation of the pump 43 becomes one rotation of the motor 44 regardless of whether the transmission is operated from any of the lowest speed to the highest speed in the transmission state. It is configured to be driven in a state of being smaller than the per-discharge oil amount. That is, even when the continuously variable transmission 40 is shifted to the maximum speed transmission state, the output speed of the continuously variable transmission 40 is set to be lower than the input speed.
[0038]
That is, if the input rotation speed of the continuously variable transmission 40 becomes low, a drive failure occurs in the continuously variable transmission 40. Regardless of the speed at which the transmission 40 is shifted, the rear wheels 2 need to be driven to transmit a driving force with a driving torque that does not cause a torque shortage. If this transmission is realized only by the deceleration transmission by the deceleration transmission mechanism 53, it is necessary to increase the deceleration transmission ratio of the deceleration transmission mechanism 53. However, the deceleration transmission mechanism 53 has a relatively small deceleration transmission ratio. In this way, the transmission is performed while reducing the size of the reduction transmission mechanism 53.
[0039]
Connecting the front body frame portion 16 and the rear body frame portion 17 of the left and right body main frames 11 to the transmission 13 and fixing the left and right lower frames 5a of the fall protection frame 5 to the body frame 10 Is performed as shown in FIGS.
[0040]
That is, the rear end portion 16a of the front vehicle body frame portion 16 as shown in FIG. 12 is a front end side of one of the port blocks 42 of the left and right continuously variable transmission 40, and the deceleration transmission case main body connected to the port block 42. The portion 42a, which is outside of the portion 50b, is abutted against the laterally outward side of the vehicle body and is tightened and connected by a plurality of connecting bolts 16b. A front end portion 17a of the rear body frame portion 17 is provided at a rear end side of one of the port blocks 42 of the continuously variable transmission 40 on the left and right sides of a portion 42b that is separated from the casing main body 41a connected to the port block 42. A plurality of connecting bolts 17b are tightened and connected to an inward side surface of the vehicle body.
The base end portions 5d of the left and right lower frame portions 5a of the fall protection frame 5 are overlapped with the one rear end portion 16a of the left and right front body frame portions 16 in the vehicle body lateral direction, and the base ends of the lower frame 5a. The side portion 5d is located on the inner side of the vehicle body with respect to the front vehicle body frame portion 16, and is tightened and connected to the front end portion 42a of the port block 42 by co-tightening with the front vehicle body frame portion 16 by the plurality of connection bolts 16b. is there.
[0041]
As shown in FIG. 14, the working clutch 36 is configured to be switched by a hydraulic operating section 37 having a piston 37a and an energizing spring 37b located inside a clutch body. A hydraulic circuit for operating the lift cylinder 8 and replenishing the left and right continuously variable transmissions 40 with oil is configured as shown in FIG.
[0042]
That is, a main oil supply passage 74 having a relief valve 72 and a hydraulic pump 73 is connected to an input port of a rotary lift valve 71 connected to the lift cylinder 8 by a lift operation oil passage 70. An input port of a rotary clutch valve 76 connected to the hydraulic operating section 37 of the working clutch 36 by a clutch operating oil passage 75 is connected to a PTO oil supply passage 77 to an oil discharge port of the lift valve 71 and to the relief valve. 72 is connected to a drainage passage 72a. The introduction port 48 a of the charge circuit 48 provided in each of the left and right continuously variable transmissions 40 is connected to the middle of the PTO oil supply passage 77 by a charge oil passage 79 having an oil filter 78. A regulator valve 80 is connected to the PTO oil supply passage 77 to regulate the oil pressure supplied to the hydraulic operation unit 36 and the charge oil passage 79 to a set oil pressure. A suction side oil supply passage 74 a of the main oil supply passage 74 connected to the suction side of the hydraulic pump 73 is communicated with the inside of the transmission case 30. A strainer 81 is provided in the suction side oil supply passage 74a.
That is, the lubricating oil stored for lubrication and cooling of the gear mechanism 33, the work transmission mechanism 35, and the work clutch 36 inside the transmission case 30 is transmitted from the transmission case 30 to the main oil supply path 74 via the strainer 81. It is taken out and supplied to the lift valve 71. When the lift valve 71 is switched to the ascending side by a lift lever 82 provided in the operation unit in conjunction with the lift valve 71 via a link-based interlocking mechanism (not shown), the lift valve 71 is switched to the main oil supply passage 74. Is supplied as hydraulic oil to the lift slider 8 via the lift operation oil passage 70, and the lift slider 8 is driven by hydraulic pressure to raise the lawn mowing device 7. When the lift valve 71 is switched to the lower side by the lift lever 82, the lift valve 71 discharges the hydraulic pressure of the lift cylinder 8 from the lift operation oil passage 70 to the PTO oil supply passage 77, and the lift cylinder 8 changes the weight of the lawn mower 7. Therefore, the mowing device 7 is moved downward by a shortening operation.
[0044]
The lubricating oil from the main oil supply passage 74 is supplied to the clutch valve 76 through the PTO oil supply passage 77. When the clutch valve 76 is switched to the inbound side by a working lever 83 provided in the operating unit in conjunction with the clutch valve 76 via a link-related interlocking mechanism (not shown), the clutch valve 76 is switched to the PTO oil supply passage. The lubricating oil from 77 is supplied as hydraulic oil to the hydraulic operating section 37 via the clutch operating oil passage 75, and the piston 37a is driven by the pressurized oil against the urging spring 37b to move the working clutch 36 to the disengagement side. Perform the switching operation. When the clutch lever 76 is switched to the input side by the work lever 83, the clutch valve 76 discharges the hydraulic pressure of the hydraulic operation section 37 from the clutch operation oil path 75 to the oil discharge path 84, and the input biasing spring 37b moves the piston 37a. Is slid to the entry side and the work clutch 36 is switched to the entry side.
[0045]
The lubricating oil from the PTO oil supply passage 77 is supplied to the charge circuits 48 of the respective continuously variable transmissions 40 through the oil filter 78 via the charge oil passages 79, and in each of the continuously variable transmissions 40, the charge circuit 48 Is supplied to the drive circuit 49 as working oil.
[0046]
As shown in FIG. 14, the strainer 81 is provided at the bottom inside the transmission case 30 with one end supported by an oil outlet 91 located on the rear wall 90 of the transmission case 30. A strainer cover 92 made of a plate member whose one end is bolted to the inner surface side of the rear wall portion 90 of the transmission case 30 is provided inside the transmission case 30. The strainer cover 92 is configured to cover the upper part of the strainer 81 so that dust such as metal powder generated and settled by the gear mechanism 33, the work transmission mechanism 35, the work clutch 36 and the like does not enter the strainer 81. In addition, the dust that has settled on the upper surface of the strainer cover 92 is slid down on the upper surface by falling guide by tilting the upper surface as viewed in the direction along the axis of the strainer 81 as shown in FIG. It is configured to be dropped on the part where it has fallen.
[0047]
As shown in FIGS. 14 to 17, each of the lift valve 71, the clutch valve 76, the relief valve 72, and the regulator valve 80 is provided in a mounting hole provided in a support portion 93 located above the main body 30 a of the transmission case 30. It is assembled. The oil filter 78 is mounted on the upper surface of the support 93. When casting the rear wall portion 90 which is detachably attached to the case main body 30a by a connecting bolt so as to open and close a rearward opening of the case main body 30a of the transmission case 30 in the vehicle body, The transmission case 30 is provided as an integral part of the rear wall portion 90 by being formed so as to extend from the upper end portion of the rear wall portion 90 above the case main body 30a and casting at the same time.
[0048]
As shown in FIG. 19, the front end side of the seat-side mounting member 95 connected to the lower side of the driver's seat 4 is rotatably connected to the seat support frame 19 around an axis 95 a in a lateral direction of the vehicle body. By rotating the driver seat 4 about the shaft center 95 a, the driver seat 4 is lowered near the front upper side of the transmission case 30 and the seat portion of the driver seat 4 is seated via the seat-side mounting member 95. The lower use posture which is received and supported on the upper surface of the driver 19, and is switched from the lower use posture to the management posture in which the seat portion of the driver's seat 4 swings up from the lower use posture and stands up with respect to the seat support frame 19. It is configured in. Further, when the driver's seat 4 is in the management posture, the driver's seat 4 is in a state of opening the upper part of the transmission case 30.
[0049]
Thus, the valves 71 and 76 and the oil filter 78 are located near the upper part of the vehicle body below the driving unit, and when the valves 71 and 76 and the oil filter 78 are checked or replaced, By switching the position 4 to the management position, the valves 71, 76 and the oil filter 78 can be easily accessed from above the vehicle body through the inspection opening 97 of the vehicle body cover 96 as shown in FIG.
[0050]
As shown in FIG. 14, the hydraulic pump 73 is configured by a trochoid pump that is disposed in a pump chamber 100 provided on the inner surface side of the rear wall portion 90 of the transmission case 30 and is rotatably attached to the input shaft 31. I have. The opening of the pump chamber 100 is closed by an inner lid 101 which is configured so that the input shaft 31 penetrates and is bolted to the inner surface of the rear wall portion 90. A bearing 102 is supported on a portion of the rear wall portion 90 located on the surface side of the rear wall portion with respect to the hydraulic pump 73, and is disposed so as to be located on the opposite side of the hydraulic pump 73 from the side where the bearing 102 is located. The bearing 103 is supported by a shaft supporting portion 104 of the case body 30a, and the pair of bearings 102 and 103 rotates the input shaft 31 with respect to the hydraulic pump 73 at one end and the other end of the input shaft 31. It is movably supported.
[0051]
As shown in FIG. 14, the main oil supply passage 74 and the PTO oil supply passage 77 are provided inside the rear wall portion 90 and the support portion 93. The charge oil passage 79 is provided inside the support portion 93 and is provided with the oil filter 78. The internal oil passage 79a is connected to an introduction port of the charge circuit 48 of the left and right continuously variable transmission 40. 48a, and an external oil passage 79b composed of a pipe. The clutch operation oil passage 75 connects a valve-side internal oil passage provided inside the support portion 93, a clutch-side internal oil passage 75b provided inside the working output shaft 34, and both internal oil passages 75b. And an external oil passage 75c formed of a pipe.
[0052]
[Another embodiment]
FIG. 20 shows a hydraulic circuit according to another embodiment, in which an oil cooler 105 acting on hydraulic oil supplied from the PTO oil supply passage 77 to the charge oil passage 79 is provided. .
[0053]
FIGS. 21 to 23 show a strainer cover 92 having another embodiment.
The strainer cover 92 shown in FIG. 21 is configured by a cylindrical body formed so that the strainer 81 enters entirely.
The strainer cover 92 shown in FIG. 22 is constituted by a rectangular tube body formed so that the strainer 81 enters entirely. Then, it is fixed to the transmission case 30 such that one corner is directed upward and the walls on both sides thereof are inclined so that the dust settled on the strainer cover 92 slides down from the strainer cover 92 by itself. is there.
The storage cover 92 shown in FIG. 23 is formed by a bent plate. Then, the bent portion is fixed to the transmission case 30 such that the bent portion is directed upward and the side surfaces on both sides thereof are inclined so that the dust settled on the strainer cover 92 naturally slides down from the strainer cover 92.
[0054]
The present invention can be applied to various types of riding vehicles such as tractors, in addition to lawnmowers. Therefore, the lawnmower, the tractor and the like are collectively referred to as a riding work vehicle, and various working devices such as the lawnmower 7 connected to the vehicle body are collectively referred to as the working device 7.
[Brief description of the drawings]
FIG. 1 is a side view of the entire riding type mower. FIG. 2 is a plan view of the entire riding type mower. FIG. 3 is a plan view of the vehicle body frame. FIG. 4 is a side view of the vehicle body frame. Rear view of the frame [FIG. 6] Rear view of the transmission in a partially cross-sectional state [FIG. 7] Schematic view of the transmission [FIG. 8] Cross-sectional view of the continuously variable transmission and the reduction transmission case [FIG. 9] Front body frame FIG. 10 is a side view as viewed from the outside of the vehicle body, showing a connection structure between the front and rear body frame portions. FIG. 10 is a side view as viewed from the inside of the vehicle body showing a connection structure between the front body frame portion and the rear body frame portion. FIG. 12 is a plan view showing a connection structure of the front body frame portion and the rear body frame portion. FIG. 12 is a perspective view showing a rear end portion of the front vehicle body frame and a base end side portion of the fall protection frame. FIG. 13 is a hydraulic circuit diagram. FIG. FIG. 15 is a rear view of the rear wall of the transmission case in a partially cut-away state. 6: A side view of the rear wall of the transmission case in a partially cut-away state. FIG. 17 is a cross-sectional view of a support part. FIG. 18 is a cross-sectional view of a strainer cover. FIG. 19 is a side view of a driver seat arrangement part. FIG. 21 is a hydraulic circuit diagram having another embodiment. FIG. 21 is a cross-sectional view of a strainer cover having another embodiment. FIG. 22 is a cross-sectional view of a strainer cover having yet another embodiment. Sectional view of strainer cover provided with
3 Engine 4 Driver Seat 7 Working Device 30 Transmission Case 30a Transmission Case Main Body 31 Input Shaft 36 Working Clutch 40 Hydrostatic Continuously Variable Transmission 73 Hydraulic Pump 74 Oil Supply Path 76 Clutch Valve 78 Oil Filter 81 Strainer 90 Rear Wall 92 Cover 93 Support part 100 Pump chamber 102 Bearing

Claims (4)

A pair of left and right running hydrostatic continuously variable transmissions is configured to be transmitted to a pair of left and right traveling hydrostatic continuously variable transmissions by a transmission case and to a working device, and the pair of left and right traveling hydrostatic continuously variable transmissions is configured. A transmission type work vehicle having a hydraulically operable work clutch for turning on and off transmission to the working device, which is provided inside the transmission case.
The transmission case includes a support portion extending upward from the case body from a rear wall portion that is detachable from the case body of the transmission case, and a clutch valve for operating the work clutch is provided on the support portion, and the transmission case is provided. And a lubricating passage connecting the clutch valve to the clutch valve and supplying lubricating oil in the transmission case to the clutch valve, the oil supply path being provided inside the rear wall. The oil pump of the oil supply passage is arranged in the pump chamber of the rear wall and is attached to the input shaft supported over the case body and the rear wall so as to be integrally rotatable, and is supported by the rear wall. The riding work vehicle according to claim 1, wherein a bearing rotatably supporting the input shaft is disposed closer to a rear wall surface than the hydraulic pump. The riding work vehicle according to claim 1 or 2, wherein a strainer that acts on lubricating oil sucked into the oil supply path and a cover that covers an upper portion of the strainer are provided inside the transmission case. An oil filter is mounted on the upper surface side of the support portion, and the driving seat is rotatably switched between a lowered use posture lowered near the upper side of the transmission case and a management posture raised from the lowered use posture. The riding work vehicle according to any one of Items 1 to 3.

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