JP2014194240A - Hydraulic device of working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the occurrence of a problem in which, for example, hydraulic oil pipes are pushed and deformed by mud, etc. in a field during work.SOLUTION: A hydraulic device of a working vehicle comprises a transmission case 21, a valve case 87 arranged in front of the transmission case 21, and hydraulic oil pipes 85 and 86 that form oil passages 80 and 81 arranged between the transmission case 21 and the valve case. The valve case 87 comprises at least one piping connection part 87A-87C in one of upper, lower, left, and right side surfaces, and the hydraulic oil pipes 85 and 86 is connected to the connection part 87B and 87C.

Description

  The present invention relates to a hydraulic device for a work vehicle including a transmission case, a valve case disposed in front of the transmission case, and a hydraulic pipe that forms an oil passage extending between the transmission case and the valve case.

  In the hydraulic equipment for a work vehicle as described above, a connecting portion for piping is provided on the front surface of the valve case disposed on the front surface of the transmission case, and a hydraulic pipe (control pipe) is connected to the connecting portion. (For example, refer nonpatent literature 1).

Japanese Patent Application No. 2012-037848 (paragraph number 0057, FIG. 4, FIG. 6)

  In the above-described configuration, it is necessary to draw the hydraulic pipe forward from the valve case when piping, so that the hydraulic pipe greatly protrudes forward of the valve case disposed in front of the transmission case. For this reason, the hydraulic pipe is likely to receive resistance from mud in the field during traveling in the field, and there is a risk that the hydraulic pipe is pushed by the mud and deformed.

  An object of the present invention is to suppress the possibility of inconvenience such as deformation of a hydraulic pipe being pushed by mud or the like in a field during work.

The problem solving means of the present invention is:
A transmission case, a valve case disposed in front of the transmission case, and a hydraulic pipe that forms an oil passage extending between the transmission case and the valve case,
The valve case includes at least one piping connection portion on any of the upper, lower, left, and right side surfaces, and the hydraulic pipe is connected to the connection portion.

  According to this means, it is not necessary to largely pull out the hydraulic pipe forward from the valve case at the time of piping, and the hydraulic pipe can be configured not to protrude from the front side of the valve case.

  This makes it possible to make the hydraulic pipe less susceptible to resistance from mud and the like in the field during work traveling in the field, and as a result, there is a risk that inconveniences such as the hydraulic pipe being pushed by the mud and deformed may occur. Can be suppressed.

As one of the means for making the present invention more suitable,
The said valve case was set as the structure provided with the said connection part in any one or both of the left side surface and the right side surface.

  According to this means, since the hydraulic pipe drawn from the left and right side surfaces of the valve case is connected to the rear transmission case, the piping is compared to the case where the hydraulic pipe drawn forward from the valve case is connected to the rear transmission case. The length can be shortened.

  In addition, piping work to the valve case can be performed from the lateral side of the valve case, which makes it easier to work than the case where the lower surface of the valve case is provided with a connecting portion and piping work is performed from below. Can be advantageous.

As one of the means for making the present invention more suitable,
The valve case is configured to include the connection portion on the upper surface thereof.

  According to this means, since the hydraulic pipe drawn from the upper surface of the valve case is connected to the rear transmission case, the pipe length is longer than when the hydraulic pipe drawn forward from the valve case is connected to the rear transmission case. Can be shortened.

  In addition, it is easier to fit the hydraulic pipe within the lateral width of the transmission case as compared with the case where the connecting portion is provided on the side surface of the valve case and the hydraulic pipe is pulled out in the lateral direction.

  Furthermore, the piping work for the valve case can be performed from above the valve case, which is advantageous in terms of workability compared to the case where the connecting portion is provided on the lower surface of the valve case and the piping work is performed from below. can do.

As one of the means for making the present invention more suitable,
The transmission case includes the valve case at a position biased to the left or right side of the front surface thereof,
The said valve case was set as the structure provided with the said connection part in the upper surface and the right-and-left side surface located in the opposite side to the bias side.

  According to this means, the hydraulic pipe pulled out from the top and left and right sides of the valve case is connected to the rear transmission case, so compared to the case where the hydraulic pipe drawn forward from the valve case is connected to the rear transmission case. The piping length can be shortened.

  In addition, since the connection part for piping is provided on the upper surface of the valve case and the lateral side opposite to the biased side in the valve case arranged so as to be deviated to the left and right of the transmission case, the hydraulic pipe is transmitted. It becomes easier to fit within the width of the case.

  Furthermore, the piping work for the valve case can be performed from above and from the outside of the valve case, so that the workability can be improved as compared with the case where the connecting portion is provided on the lower surface of the valve case and the piping work is performed from below. Can be advantageous in terms of surface.

As one of the means for making the present invention more suitable,
The connection portion is configured to connect the hydraulic pipe from above.

  According to this means, for example, the valve case is formed in a shape having a protruding portion that protrudes laterally outward from the lateral side portion thereof, and a piping connection portion is provided on the upper surface of the protruding portion. For example, although the connection portion for piping is provided on the lateral side portion of the valve case, the hydraulic pipe can be connected to the connection portion from above.

  That is, regardless of the arrangement of the connecting portions, all piping work for the valve case can be performed from above the valve case, and as a result, it is advantageous in terms of workability.

As one of the means for making the present invention more suitable,
The connection portion provided on one or both of the left side surface and the right side surface of the valve case has an elbow so that the hydraulic pipe can be connected from above.

  According to this means, regardless of the arrangement of the connecting portion, all piping work for the valve case can be performed from above the valve case, and as a result, it is advantageous in terms of workability.

As one of the means for making the present invention more suitable,
The transmission case includes hydraulic left and right side clutches that intermittently transmit power to the left and right traveling devices,
The hydraulic pipe includes a first hydraulic pipe for the left side clutch and a second hydraulic pipe for the right side clutch,
The valve case includes a first connection part for a first hydraulic pipe and a second connection part for a second hydraulic pipe as the connection part.

  According to this means, it is possible to enable clutch rotation in which transmission to either the left or right traveling device is interrupted by hydraulic operation of the side clutch. In addition, the first hydraulic pipe and the second hydraulic pipe that enable the clutch to rotate can be configured not to protrude forward from the valve case when piping, and not to protrude from the front side of the valve case. it can.

  This makes it possible to make the first hydraulic pipe and the second hydraulic pipe difficult to receive resistance from mud and the like in the field during clutch turning in the field, and as a result, the first hydraulic pipe and the second hydraulic pipe are mud. It is possible to suppress the possibility of inconveniences such as being deformed by being pushed by the.

As one of the means for making the present invention more suitable,
A supply hydraulic pipe that forms an oil supply path extending from the hydraulic pump to the valve case;
The valve case includes a supply connection portion that enables connection of the supply hydraulic pipe as one of the connection portions.

  According to this means, it is not necessary to pull out the supply hydraulic pipe greatly forward from the valve case during piping, and the supply hydraulic pipe can be configured not to protrude forward from the front surface of the valve case.

  This makes it difficult for the supply hydraulic pipe to be subjected to resistance from mud in the field when working on the field, and as a result, the supply hydraulic pipe is pushed by the mud and deformed. It is possible to suppress the possibility of occurrence of

As one of the means for making the present invention more suitable,
The transmission case includes a bulging portion that bulges forward,
The valve case is arranged at a site different from the bulging portion in the transmission case and does not protrude forward from the front end of the bulging portion.

  According to this means, the hydraulic pipe and the valve case can be configured not to protrude forward from the front end of the bulging portion of the transmission case.

  This makes it difficult for the valve case and the hydraulic pipe to receive resistance from mud and the like in the field during work traveling in the field, and as a result, the valve case and the hydraulic pipe are pushed by the mud and adversely affected. The possibility of inconvenience can be suppressed.

As one of the means for making the present invention more suitable,
The transmission case is equipped with a continuously variable transmission on the outer surface of the upper portion thereof, and includes an oil supply pipe that enables oil supply into the transmission case,
The continuously variable transmission has an upper end located above the upper end of the transmission case,
The oil supply pipe extends upward so that the oil supply port at the upper end is positioned above the upper end of the continuously variable transmission.

  According to this means, replenishment of oil from the oil supply port of the oil supply pipe to the inside of the transmission case can be easily performed from above the continuously variable transmission without being obstructed by the continuously variable transmission. Further, it is possible to effectively suppress the intrusion of muddy water from the oil filler opening in a field with much water.

As one of the means for making the present invention more suitable,
The transmission case is equipped with a continuously variable transmission on the outer surface of the upper portion thereof, and includes an oil supply pipe that enables oil supply into the transmission case,
The oil supply pipe extends upward in an inclined posture in which the oil supply port at the upper end is separated from the continuously variable transmission.

  According to this means, oil can be easily supplied from the oil supply port of the oil supply pipe into the transmission case without being obstructed by the continuously variable transmission. Further, it is possible to suppress the intrusion of muddy water from the fuel filler opening in a field with a lot of water.

As one of the means for making the present invention more suitable,
The transmission case includes an oil supply pipe that enables oil supply to the inside thereof,
The oil supply pipe extended upward in an inclined posture toward the upper front side of the transmission case.

  According to this means, oil can be easily supplied from the oil supply port of the oil supply pipe to the inside of the transmission case from the upper front side of the transmission case. Further, it is possible to suppress the intrusion of muddy water from the fuel filler opening in a field with a lot of water.

As one of the means for making the present invention more suitable,
The transmission case includes an oil supply pipe that enables oil supply to the inside thereof,
The oil supply pipe is located on the lateral outer side of the side panel provided in the boarding operation unit, and extends upward so that the oil supply port at the upper end is located near the upper end of the side panel.

  According to this means, oil can be easily supplied from the oil supply port of the oil supply pipe to the inside of the transmission case from the boarding operation unit. Further, it is possible to prevent the infiltration of muddy water from the oil filler opening in a field with much water.

It is a right view of a normal combine. It is a top view of a normal combine. It is a right view of a transmission case and a hydrostatic continuously variable transmission. It is a front view of a transmission case and a hydrostatic continuously variable transmission. It is a left view of a transmission case and a hydrostatic continuously variable transmission. It is a vertical front view of a transmission case and a hydrostatic continuously variable transmission. It is a vertical front view of the left and right side clutch brake units. FIG. 2 is a hydraulic circuit diagram relating to a hydrostatic continuously variable transmission and left and right side clutch brake units. It is a partially longitudinal right side view showing a retaining structure of a rotating shaft. It is a vertical right side view which shows the structure of the switching valve for priority deceleration. It is a vertical front view of the principal part which shows the structure of a variable relief valve. It is a perspective view of the principal part which shows the support structure of a gasket. It is a left view of the principal part which shows another structure of an oil supply pipe | tube.

  Hereinafter, as an example of a mode for carrying out the present invention, an embodiment in which a hydraulic device for a working vehicle according to the present invention is applied to a normal combine that is an example of a working vehicle will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the ordinary combine exemplified in the present embodiment cuts an uncut grain culm to be harvested that is located in front of the vehicle body at the left side of the front end of the vehicle body 1 at the time of work traveling. The cutting and conveying device 2 that conveys rearward is connected so as to be movable up and down while extending toward the front of the traveling vehicle body 1. The left half of the traveling vehicle body 1 is equipped with a threshing device 3 that performs a handling process on the harvested cereal meal conveyed by the harvesting and conveying apparatus 2 and performs a sorting process on a processed product obtained by the handling process. A grain tank 5 that stores the grain that has been fed from the bottom of the threshing device 3 via the lifting conveyor 4 is mounted on the rear half of the right half of the traveling vehicle body 1. The grain tank 5 is equipped with a screw conveying type grain discharging device 6 for discharging the grains stored in the grain tank 5 to the outside of the machine. And these are configured to harvest rice, wheat or soybeans.

  In addition, it replaces with the grain tank 5 and the grain discharge | emission apparatus 6 in the traveling vehicle body 1, and equips the bagging apparatus which enables the filling of the grain lifted with the lifting conveyor 4 to the straw bag. Good.

  The traveling vehicle body 1 is provided with a pair of left and right crawlers 8 as left and right traveling devices A at a lower portion of a vehicle body frame 7 formed by connecting a plurality of steel materials such as a square pipe material. A boarding operation unit 9 is formed at a front half of the right half of the body frame 7, and a water-cooled diesel engine (hereinafter referred to as an engine) 11 is provided below a driver seat 10 provided on the rear side of the boarding operation unit 9. Etc. are deployed.

  As the traveling device A, a pair of left and right front wheels and a pair of left and right rear wheels may be employed, or a pair of left and right front wheels and a pair of left and right rear crawlers may be employed.

  The reaping and conveying apparatus 2 has a pair of left and right dividers 12 that separates uncut cereals into harvested and non-harvested cereals as the vehicle travels, at the left and right ends of the front end. doing. A rotary reel 13 is disposed above the front part of the cutting and conveying device 2 so that the tip of the harvested grain culm divided by the left and right dividers 12 is scraped back. A clipper-shaped cutting mechanism 14 that cuts the stock source side of the harvest target cereal is provided at the bottom of the cutting and conveying device 2, and the harvested cereal that has been cut by the cutting mechanism 14 is placed at the rear of the cutting mechanism 14. An auger drum 15 is provided that gathers at a predetermined position in the left-right direction and then feeds back from the predetermined position. And immediately behind the predetermined location, a feeder 16 comprising a slat conveyor is provided for feeding and conveying the harvested cereals fed rearward from the predetermined location toward the cereal input (not shown) of the threshing device 3. doing.

  The cutting and conveying apparatus 2 is a laterally-oriented feeder drive shaft that also serves as an input shaft of the cutting and conveying apparatus 2 provided at the rear end of the feeder 16 by the operation of a hydraulic lifting cylinder 17 installed over the body frame 7 and the feeder 16. It swings up and down using a fulcrum (not shown). The lifting cylinder 17 is actuated by cutting and lifting the cross-swing type neutral return type control lever 18 provided at the front of the boarding operation unit 9 in the front-rear direction to change the operating pressure on the lifting cylinder 17. It can be controlled by switching the operating state of a valve unit (not shown). That is, the cutting and conveying device 2 can be moved up and down by swinging the control lever 18 in the front-rear direction, and cutting height adjustment for changing the height position of the cutting mechanism 14 with respect to the harvested culm is performed. Can do.

  As shown in FIGS. 1 and 3 to 7, the power from the engine 11 is generated by a belt-type transmission 19, a hydrostatic continuously variable transmission (hereinafter referred to as HST) 20, which is an example of a continuously variable transmission B, And, it is transmitted to the left and right crawlers 8 via a traveling transmission system 22 incorporated in the transmission case 21. The HST 20 and the transmission case 21 are arranged at the center of the front of the traveling vehicle body 1 so as to be positioned below the side panel 23 arranged at the left end of the boarding operation unit 9.

  The continuously variable transmission 20 may be a belt-type continuously variable transmission, a hydraulic mechanical continuously variable transmission [HMT], or the like.

  The HST 20 includes a hydraulic pump 25 and a hydraulic motor 26 inside the transmission case 24. The pump shaft of the hydraulic pump 25 also serves as the input shaft 20A of the HST 20, and the motor shaft of the hydraulic motor 26 serves as the output shaft 20B of the HST 20 as well. The transmission case 24 includes a case member 27 in which an accommodation recess 27A that accommodates the hydraulic pump 25 and the hydraulic motor 26 is formed, and a port block 28 that closes the accommodation recess 27A. The hydraulic pump uses an axial plunger type variable displacement pump. An axial plunger type constant variable capacity motor is used as the hydraulic motor.

  An axial plunger type variable displacement motor may be employed as the hydraulic motor.

  As shown in FIGS. 1, 6, and 7, the traveling transmission system 22 is provided with a small-diameter input gear 29 integrally formed with a cylindrical shaft portion 29 </ b> A that is spline-fitted to the output shaft 20 </ b> B of the HST 20. That is, the cylindrical shaft portion 29 </ b> A of the input gear 29 is configured to be the input shaft of the traveling transmission system 22. Then, the power after the shift by the HST 20 taken in by the input gear 29 is used as a reduction unit 30, left and right side clutch brake units 31, left and right output gears 32, and left and right output shafts 33 that rotate integrally with the corresponding output gear 32. , And are transmitted to the left and right crawlers 8.

  The traveling transmission system 22 may have a configuration including a sub-transmission device capable of shifting in multiple stages. Moreover, the structure provided with the right and left reverse transmission unit which enables transmission of reverse rotation power to the corresponding crawler 8 on either side may be sufficient.

  The reduction unit 30 includes a large-diameter first reduction gear 34 that meshes with the input gear 29, a small-diameter second reduction gear 36 that is spline-fitted to the first relay shaft 35 together with the first reduction gear 34, and a second reduction gear. 36, a large-diameter third reduction gear 37 that meshes with 36, and the like. The third reduction gear 37 is spline-fitted to the second relay shaft 39 in a state in which the third reduction gear 37 is fixed to be non-slidable by a stopper 38.

  The left and right side clutch brake units 31 are composed of a meshing type side clutch 40 and a multi-plate type side brake 41. The left and right side clutches 40 are cylindrically movable pawl shafts 42 fitted on the center side of the second relay shaft 39 so as to be relatively rotatable and relatively slidable, and are not slidable on the end side of the second relay shaft 39. A ring-shaped fixed claw shaft 43 that is spline-fitted in a state, a compression spring 44 that slidably urges the movable claw shaft 42 in a direction to engage with the fixed claw shaft 43, and the like. The movable claw shaft 42 is slidably displaced over a meshing position where it engages with the fixed claw shaft 43 and a release position where the meshing with the fixed claw shaft 43 is released. The left and right side brakes 41 include a plurality of brake discs 45 that are spline-fitted to the movable claw shaft 42, a plurality of separator plates 46 that are alternately fitted to the movable claw shaft 42 alternately with the brake disc 45, and a pressure plate 47. It is composed. A collar 48 that allows a series of sliding operations of the movable claw shaft 42 and the pressure plate 47 is fitted on the outer end portion of each movable claw shaft 42.

  The left and right side clutch brake units 31 are provided with cylindrical pistons 49 that enable hydraulic operation of the movable claw shaft 42 and the pressure plate 47 via the collar 48. The left and right pistons 49 are slidably displaced from the meshing position to the release position by sliding the movable pawl shaft 42 in the direction against the action of the compression spring 44 as the pressure is increased, thereby causing the corresponding side clutch 40 to move. The transmission state is switched from a transmission state to a cutoff state where transmission is cut off, and then the pressure plate 47 is slid in the direction against the action of the compression spring 44 together with the movable claw shaft 42 to press each separator plate 46 and the pressure plate 47. By doing so, the corresponding side brake 41 is configured to be switched from the braking release state to the braking state. In addition, by allowing the movable claw shaft 42 to be slid by the action of the compression spring 44 as the pressure is reduced, the pressure plate 47 releases the pressure on each separator plate 46 and the pressure plate 47 and the corresponding side brake. 41 is switched from the braking state to the braking release state, and then the movable claw shaft 42 is slid and displaced from the release position to the meshing position, and the corresponding side clutch 40 is switched from the disconnected state to the transmission state.

  That is, in the left and right side clutch brake units 31, the side brake 41 is switched from the brake release state to the brake state after the side clutch 40 is switched from the transmission state to the cutoff state by the pressure increase, and the side brake 41 is released from the brake state by the pressure reduction. The hydraulic clutch is configured such that the side clutch 40 is switched from the disconnected state to the transmission state after switching to the braking release state.

  Note that the left and right side clutch brake units 31 may be configured to be, for example, an electric type that switches the operating states of the side clutch 40 and the side brake 41 as described above by operating an electric cylinder.

  The left and right output gears 32 mesh with the movable claw shafts 42 of the corresponding side clutch brake units 31. The power or braking force is transmitted to the left and right crawlers 8 via the corresponding output shafts 33.

  As shown in FIGS. 3 to 7 and FIG. 9, the transmission case 21 has a left and right divided structure that can be divided into left and right from the left first case member 51 and the right second case member 52. And in the state which joined the outer peripheral part of the 1st case member 51, and the outer peripheral part of the 2nd case member 52, the input gear 29 of the driving | running | working transmission system 22 is accommodated by bolting several places of those outer peripheral parts. And a second case portion 21B that accommodates the speed reduction unit 30 of the traveling transmission system 22, the left and right output gears 32, and the like. Further, the third case member 53 is bolted to the outer surface of the first case member 51 to form a third case portion 21C that accommodates the left side clutch brake unit 31 and the like. A fourth case member 21D that accommodates the right side clutch brake unit 31 and the like is formed by bolting the fourth case member 54 to the side surface. The third case member 53 and the fourth case member 54 have openings 53A that allow assembly of the corresponding side clutch brake units 31 from the left and right lateral outer sides with respect to the third case portion 21C and the fourth case portion 21D, 54A is formed, and the left and right cover member 55 that closes the openings 53A and 54A is bolted. The left and right cover members 55 support the end of the second relay shaft 39 and the piston 49, and form a piston operating oil chamber 21E between the corresponding third case member 53 and the fourth case member 54. ing. A left and right output shaft case 56 that surrounds the output shaft 33 extending from the transmission case 21 to the left and right is connected to the lower portion of the first case member 51 and the second case member 52 by bolts.

  As shown in FIGS. 3 to 6, the first case portion 21 </ b> A of the transmission case 21 has a left first outer wall portion 21 a that supports the input gear 29 and a right second outer wall portion 21 b adjacent to the input gear 29. It is narrow. An opening that allows spline fitting between the cylindrical shaft portion 29A of the input gear 29 and the output shaft 20B of the HST 20 is formed in the central portion of the first outer wall portion 21a. A connection surface 21c that enables the connection of the HST 20 is formed in a portion around the input gear 29 located around the input gear 29 on the outer surface of the first outer wall portion 21a. Four through holes 21d that allow the HST 20 to be connected to the connecting surface 21c are formed in the input gear peripheral portion located around the input gear 29 in the first outer wall portion 21a and the second outer wall portion 21b. The case member 27 of the HST 20 has a joint surface 27a that is joined to the connection surface 21c of the first outer wall portion 21a at the output shaft peripheral portion located around the output shaft in the right outer wall portion located on the opposite side of the port block 28. , Four screw holes 27b corresponding to the respective through holes 21d of the first case portion 21A are formed. The connecting surface 21c of the first case portion 21A is provided with a positioning pin 57 for the case member 27 of the HST 20, and a positioning hole 27c for the first case portion 21A of the transmission case 21 is formed in the joint surface 27a of the case member 27. ing.

  When the HST 20 is coupled to the transmission case 21 from the above configuration, first, the coupling surface 21c formed on the first outer wall portion 21a of the transmission case 21 and the joint surface 27a formed on the case member 27 of the HST 20 are opposed to each other. In this state, the output shaft 20B of the HST 20 is spline-fitted to the cylindrical shaft portion 29A of the input gear 29, and the positioning pin 57 of the connecting surface 21c is engaged with the positioning hole 27c of the joining surface 27a. Thereby, HST20 can be positioned with respect to the transmission case 21 in the state in which each through-hole 21d of the transmission case 21 and each screw hole 27b of HST20 oppose appropriately. After this positioning, four bolts 58 as screwing members for the respective screw holes 27b are inserted into the corresponding through holes 21d from the right outer side of the transmission case 21 and screwed into the corresponding screw holes 27b. The HST 20 can be easily connected to the case 21 from the right outer side of the transmission case 21 in a state where the joint surface 27a of the case member 27 is appropriately joined to the connection surface 21c of the first outer wall portion 21a. Further, by this screwing, the connection of the first case member 51 and the second case member 52 in the transmission case 21 at the first case portion 21A can be further strengthened. And in this connection state, since the port block 28 which is easy to heat up with a high pressure is located in the outer side away from the transmission case 21, the heat radiation from the port block 28 can be promoted, and the rise in the oil temperature is suppressed. be able to.

  That is, the output shaft 20B of the HST 20 and the input gear 29 of the transmission case 21 can be interlocked by the four screw holes 27b formed in the case member 27 of the HST 20 and the four bolts 58 screwed into these. The connecting means C for appropriately connecting the transmission case 21 and the HST 20 is configured.

  Note that the transmission case 21 is formed with a connecting surface 21c at the peripheral portion of the input gear 29 located around the input gear 29 on the outer surface of the second outer wall portion 21b, so that the HST 20 is connected to the second outer wall from the left outer side of the transmission case 21. You may comprise so that it may connect in the state which joined the joint surface 27a of the case member 27 to the connection surface 21c of the part 21b. The HST 20 may be configured to be connected to the transmission case 21 in a state where the joint surface 27 a is formed on the port block 28 and the port block 28 is joined to the transmission case 21. The transmission case 24 of the HST 20 is provided with stud bolts as four screwing portions 27b, and the connecting means C is constituted by these stud bolts and four nuts as screwing members 58 screwed into the stud bolts. May be. The number of screwing portions 27b and screwing members 58 may be two, three, or five or more. A positioning hole may be formed in the connecting surface 21c of the transmission case 21 and a positioning pin 57 may be provided on the joint surface 27a of the HST 20.

  The input shaft 20 </ b> A of the HST 20 is located at a position deviating upward from a position facing the transmission case 21 in a state where the HST 20 is coupled to the transmission case 21. The protruding portion of the input shaft 20A that protrudes rightward from the case member 27 of the transmission case 24 has a length such that the protruding end portion is located on the right outer side of the second outer wall portion 21b of the transmission case 21, and The output pulley of the belt type transmission 19 is provided as an input pulley 59 at the protruding end portion. The case member 27 includes a shaft support portion 27B that extends to the vicinity of the protruding end portion of the input shaft 20A and supports the protruding end side of the input shaft 20A. The shaft support portion 27 </ b> B is provided with a plurality of heat sinks 27 </ b> C using a space between the HST 20 and the input pulley 59, thereby improving the cooling efficiency of the HST 20. The input pulley 59 can be attached from the right outer side of the transmission case 21 to the protruding end portion of the input shaft 20A. When the input pulley 59 is attached to the protruding end portion of the input shaft 20A, four bolts 58 are attached in the assembly direction. It overlaps with the upper two of them.

  That is, the connection between the HST 20 and the transmission case 21 is performed using the space between the HST 20 and the input pulley 59, so that the left and right sides of the traveling transmission system 22 can be moved from the input shaft 20 A of the HST 20. The speed change transmission system over the output shaft 33 can be configured compactly.

  As shown in FIGS. 1 to 8, the left and right side clutch brake units 31 are linked to the control lever 18 via a control unit D and the like. The control unit D changes the relief pressure for the left and right side clutch brake units 31 based on the switching valve 60 that switches the oil flow to the left and right side clutch brake units 31 based on the operation of the control lever 18 and the operation of the control lever 18. The valve unit 63 includes a variable relief valve 61 and a relief valve 62 that opens when the internal pressure of the left and right side clutch brake units 31 exceeds a set value.

  Note that the control unit D may adopt an electrohydraulic control type using an electromagnetic valve. In addition, when the left and right side clutch brake units 31 are configured electrically, an electronic control type is adopted.

  When the control lever 18 is positioned in the straight traveling position, the control unit D maintains the pressure-reducing state in which the left and right side clutch brake units 31 are depressurized, maintains the left and right side clutches 40 in the transmission state, and The side brake 41 is maintained in a brake release state. As a result, it is possible to obtain a straight traveling state in which the left and right crawlers 8 are driven at a constant speed and the vehicle body travels straight. When the control lever 18 is operated to the left from the straight position, the left side clutch 40 is moved from the reduced pressure state to the left pressure increasing state in which the left side clutch brake unit 31 acting on the left crawler 8 is increased. After switching from the transmission state to the cutoff state, the left side brake 41 is switched from the braking release state to the braking state with an operation amount corresponding to the operation amount to the left of the control lever 18. Thereby, it is possible to switch from the straight traveling state to the left turning state in which the left crawler 8 is driven or braked to turn the vehicle body leftward. When the control lever 18 is operated rightward from the straight traveling position, the right side clutch 40 is moved from the reduced pressure state to the right pressure increasing state in which the right side clutch brake unit 31 acting on the right crawler 8 is increased. After switching from the transmission state to the cutoff state, the right side brake 41 is switched from the braking release state to the braking state with an operation amount corresponding to the operation amount to the right of the control lever 18. Thereby, it is possible to switch from the straight traveling state to the right turning state in which the right crawler 8 is driven or braked to turn the vehicle body in the right direction. When the control lever 18 is operated from one of the left and right operation positions toward the straight traveling position, the side brake 41 in the braking state is switched to the braking release state by switching from the left pressure increasing state or the right pressure increasing state to the pressure decreasing state. Thereafter, the side clutch 40 in the disconnected state is switched to the transmission state. Thereby, it can switch from a left turn state or a right turn state to a straight drive state.

  That is, the control lever 18 is configured to function as the first operation tool E for steering. In addition, as the first operating tool E, a steering wheel that rotates in the turning direction may be employed.

  As shown in FIGS. 1-4 and FIGS. 6-8, the parking brake pedal 64 is arrange | positioned as the 2nd operation tool F for parking brake operation in the step part of the boarding operation part 9. As shown in FIG. The parking brake pedal 64 is returned to the depression release position by urging a return spring (not shown), and can be held at the depression position by the depression operation to the depression position against the action of the return spring. The position holding at the depressed position can be released by the depression operation in the holding state. The right side brake 41 switches from the braking release state to the braking state in conjunction with the depression operation to the depression position, and the right side brake 41 brakes from the braking state in conjunction with the return to the depression release position. The vehicle is linked to the right side brake 41 via the parking brake switching mechanism 65 and the like so as to switch to the released state. That is, the right side brake 41 is configured to function as the parking brake G.

  The left side brake 41 may function as the parking brake G. Further, a dedicated parking brake G that brakes the left and right crawlers 8 via the left and right side clutch brake units 31 may be provided.

  The parking brake switching mechanism 65 has a ring-shaped operation member 66 fitted on the collar 48 so as to act on the pressure plate 47, and a rotation shaft that engages with the operation member 66 in a state in which the operation member 66 can be rotated. 67, the operation arm 68 connected to the right end of the rotation shaft 67, and the fourth case member 54 and the operation member 66 so as to slide and displace the operation member 66 in the left-right direction as the operation member 66 rotates. And a climbing cam mechanism 69 formed between the two. The operation arm 68 is linked to the parking brake pedal 64 via a mechanical linkage mechanism (not shown). As a result, the rotation shaft 67 rotates forward in conjunction with the depression operation of the parking brake pedal 64 to the depression position, and the operation member 66 rotates forward and slides in the left direction in conjunction with the forward rotation. Thus, the pressure plate 47 is pressed to switch the right side brake 41 from the braking release state to the braking state. The rotary shaft 67 reverses in conjunction with the return of the parking brake pedal 64 to the depressing release position, and the operating member 66 reverses in conjunction with the reverse rotation and slides in the right direction. 47 is released, and the right side brake 41 is configured to switch from the braking state to the braking release state.

  As a result, the parking brake pedal 64 is held in the depressed position while the control lever 18 is positioned in the straight traveling position, so that the braking force by the right side brake 41 is applied to the left and right side clutch brake units 31 via the left and right side clutch brake units 31. It can be made to act on the crawler 8, and it can switch to the parking state which maintains the state which stopped the vehicle body by braking.

  In addition, as the second operation tool F, an operation lever or a switch configured to be able to switch and hold between the parking position and the parking release position may be employed. The parking brake switching mechanism 65 is an electric type that switches the right side brake 41 from the braking release state to the braking state by cutting off the energization, or a hydraulic type that switches the right side brake 41 from the braking release state to the braking state by pressure reduction. You may comprise.

  As shown in FIGS. 3 to 9, the transmission case 21 is connected to the opening 54 </ b> A for assembling the side clutch brake unit on the right side of the transmission case 21. A recess 21 </ b> F that enables the fitting of the moving shaft 67 is formed. The left and right cover members 55 are integrally formed with an extraction preventing portion 55A that prevents the rotation shaft 67 from coming out of the recess 21F via a C-shaped ring 70 that is engaged with the right end of the rotation shaft 67. doing.

  As shown in FIGS. 6 to 8 and FIG. 10, the transmission case 21 operates the control unit D when the right side brake 41 (parking brake G) is switched to the braking state by depressing the parking brake pedal 64. Regardless of the state, an interlocked state maintaining mechanism H is provided that maintains the side clutch 40 of the left and right side clutch brake units 31 in the connected state and maintains the left and right crawlers 8 in the interlocked state.

  When the right side brake 41 is switched to the braking state by the depressing operation of the parking brake pedal 64, the interlocking state maintaining mechanism H and the oil chamber 21E for operating the piston provided in the left and right side clutch brake units 31 and the discharge oil passage In this state, the left and right oil chambers 21E are communicated with the discharge oil passage 72 from the stoppage state (see FIG. 10A) in which the communication with the 72 is cut off and the oil discharge from the left and right oil chambers 21E is stopped. Priority is given to decompressing the left and right side clutch brake units 31 in preference to the control unit D by switching to a discharge state (see FIG. 10B) that allows oil to be discharged from the left and right oil chambers 21E. The switching valve 71 is used as the pressure reducing means Ha. The switching valve 71 includes a rotating shaft 67 and a switching oil passage 73 formed on the rotating shaft.

  In the parking state in which the parking brake pedal 64 is held in the depressed position and the braking force from the right side brake 41 is applied to the left and right crawlers 8 via the left and right side clutch brake units 31 from the above configuration. Even when the control lever 18 is operated to the left or right from the straight traveling position by the above, it is possible to prevent the pressure increase of the left or right side clutch brake unit 31 based on the operation of the control lever 18. As a result, in a parking state on an inclined ground, due to an erroneous operation of the control lever 18, either the left or right side clutch brake unit 31 is boosted, and either the left or right side clutch 40 is switched from the connected state to the disconnected state. Further, it is possible to avoid the possibility that the braking force by the right side brake 41 does not act on the left crawler 8 and the vehicle body turns, for example.

  The interlocking state maintaining mechanism H may employ a configuration that prevents the operation of the control lever 18 from the straight position in the left-right direction in the parking state. The priority pressure reducing means Ha may be configured by a dedicated switching valve that is separate from the rotating shaft 67. Further, an electromagnetic valve may be adopted as the switching valve 60 of the control unit D so that the switching valve 60 is maintained in a reduced pressure state in preference to the operation of the control lever 18.

  As shown in FIGS. 3 to 6 and 8, the port block 28 of the HST 20 is connected with a first hydraulic pump 74 for charging and a second hydraulic pump 75 for steering driven by the input shaft 20 </ b> A of the HST 20. Yes. The first hydraulic pump 74 sucks lubricating oil stored in the transmission case 21 through the suction oil passage 76 and the oil filter 77 and supplies the oil to the HST 20 through the charge oil passage 78 and the like. The second hydraulic pump 75 sucks the lubricating oil stored in the transmission case 21 through the suction oil passage 76 and the oil filter 77 and supplies the oil to the valve unit 63 through the oil supply passage 79 and the like. The valve unit 63 supplies oil from the second hydraulic pump 75 to the oil chambers 21E of the left and right side clutch brake units 31 via the switching valve 60, the left and right supply / discharge oil passages 80 and 81, and the like. Further, the oil in the oil chambers of the left and right side clutch brake units 31 is changed to the switching valve 60 and the left and right supply / discharge oil passages 80 and 81 and the discharge oil passage 72, or the relief oil passage 82 and the variable relief valve 61 or the relief valve 62. Alternatively, the oil is discharged into the transmission case 21 through the switching oil passage 73 and the discharge oil passage 72.

  The suction oil passage 76 has an external oil passage portion formed by a steel pipe suction hydraulic pipe 83 extending from the lower part of the transmission case 21 to the upper part of the transmission case 24. The oil supply passage 79 has an external oil passage portion formed by a steel pipe supply hydraulic pipe 84 extending from the second hydraulic pump 75 to the valve unit 63. The left oil supply / discharge oil passage 80 has an external oil passage portion formed by a first hydraulic pipe 85 made of a steel pipe extending between the left side of the transmission case 21 and the valve unit 63. The right oil supply / discharge oil passage 81 has an external oil passage portion formed by a second hydraulic pipe 86 made of steel pipe extending between the right side of the transmission case 21 and the valve unit 63.

  As described above, when connecting the HST 20 to the transmission case 21, the spline fitting between the output shaft 20B of the HST 20 and the cylindrical shaft portion 29A of the input gear 29 on the transmission case side, and the positioning hole 27c of the HST 20 and the transmission are performed. By the engagement of the case 21 with the positioning pin 57, the HST 20 can be properly positioned with respect to the transmission case 21. This prevents variations in the distance between the connecting portion 21H to the suction hydraulic pipe 83 provided at the lower portion of the transmission case 21 and the connecting portion 20C to the suction hydraulic pipe 83 provided at the upper portion of the HST 20. Thus, the connection between the transmission case 21 and the HST 20 by the suction hydraulic pipe 83 can be facilitated.

  As shown in FIGS. 3 to 6, the transmission case 21 is formed such that the lower side that houses the left and right output gears 32 is a bulging portion 21 </ b> G that bulges forward from the upper side. The valve unit 63 is bolted to the front right side portion of the transmission case 21 on the upper side of the bulging portion 21G so as not to protrude forward from the front end of the bulging portion 21G. The valve case 87 of the valve unit 63 has a supply connecting portion 87A that enables connection of the supply hydraulic tube 84 and a first connection portion 87B that enables connection of the first hydraulic tube 85 on the left side surface. I have. Further, a second connection portion 87C that enables connection of the second hydraulic pipe 86 is provided on the upper surface. An elbow 88 that connects the supply hydraulic pipe 84 and the first hydraulic pipe 85 to the supply connection section 87A and the first connection section 87B from above is connected to the supply connection section 87A and the first connection section 87B.

  The second hydraulic pump 75 has a supply connection portion 75 </ b> A that enables connection of the supply hydraulic pipe 84 formed on the front surface thereof. The transmission case 21 includes a first connection portion 53B that enables connection of the first hydraulic pipe 85 to the front surface of the third case member 53, and a connection of the second hydraulic pipe 86 to the front surface of the fourth case member 54. A second connection portion 54B is provided that enables this. An elbow 88 that enables connection of the first hydraulic pipe 85 and the second hydraulic pipe 86 from above is connected to the first connecting portion 53B and the second connecting portion 54B.

  The supply hydraulic pipe 84 is behind the front end of the bulging portion 21G in the transmission case 21 in a state where the supply connection portion 75A of the second hydraulic pump 75 and the supply connection portion 87A of the valve case 87 are connected. In a positioned state, it is bent so as to fit within the left and right width of the HST 20 and within the left and right width of the transmission case 21. The first hydraulic pipe 85 is bent and formed in a substantially U shape that is upside down. The second hydraulic pipe 86 is bent and formed in a substantially J shape that is upside down.

  From the above configuration, the connection of the first hydraulic pipe 85 to the first connection portion 53B of the transmission case 21 and the first connection portion 87B of the valve case 87 can be easily performed by a connection operation from above. The first hydraulic pipe 85 is positioned behind the front end of the bulging portion 21G in the transmission case 21 in a state where it is connected to the first connection portion 53B of the transmission case 21 and the first connection portion 87B of the valve case 87. In such a state, the HST 20 fits within the left-right width and the transmission case 21 fits within the left-right width. Further, the second hydraulic pipe 86 can be easily connected to the second connecting portion 54B of the transmission case 21 and the second connecting portion 87C of the valve case 87 by a connecting operation from above. The second hydraulic pipe 86 is positioned behind the front end of the bulging portion 21G in the transmission case 21 in a state where the second hydraulic pipe 86 is connected to the second connection portion 54B of the transmission case 21 and the second connection portion 87C of the valve case 87. In such a state, it fits within the lateral width of the transmission case 21.

  The valve case 87 has a supply connection portion 87A, a first connection portion 87B, and a second connection portion 87C connected to one or several of the left side surface, the right side surface, the top surface, and the bottom surface. Alternatively, a distributed connection may be configured. The valve case 87 has a shape having a projecting portion projecting laterally outward from the lateral side portion thereof, and the lateral side portion of the valve case 87 is configured to include a connecting portion for piping on the upper surface of the projecting portion. However, the hydraulic pipe may be connected to the connecting portion from above. The valve unit 63 may be bolted to the front left side of the transmission case 21 on the upper side of the bulging portion 21G so as not to protrude forward from the front end of the bulging portion 21G.

  As shown in FIGS. 3 to 5, the transmission case 21 includes an oil supply pipe 89 that allows oil to be supplied to the inside of the transmission case 21. The oil supply pipe 89 is inclined so as to be separated from the HST 20 and the input pulley 59 to the right front side, and the upper end of the oil supply port 89A and the breather 90A provided in the cap 90 for opening and closing the oil supply port 89A are located above the upper end of the HST 20 It extends upward to be located at

  Thereby, the oil supply from the oil supply port 89A of the oil supply pipe 89 to the inside of the transmission case 21 can be easily performed from the front upper side of the oil supply port 89A without being hindered by the HST 20 and the input pulley 59. Moreover, the oil blow-up from the transmission case 21 can be more effectively suppressed, and the intrusion of muddy water from the breather 90A or the like in a field with much water can be effectively suppressed.

  Note that the oil supply pipe 89 may extend directly above such that the upper oil supply port 89A is located above the upper end of the HST 20. Moreover, you may extend upward in the inclination attitude | position which leaves | separates from HST20 and the input pulley 59 to the front side. Furthermore, as shown in FIG. 13, the side panel 23 provided in the boarding operation unit 9 is located on the left outer side, and the upper filler port 89 </ b> A extends upward so as to be located near the upper end of the side panel 23. May be.

  As shown in FIG. 11, in the valve unit 63, the operation shaft 91 rotates in conjunction with the swinging operation of the control lever 18 in the left-right direction, so that the cam 92 provided on the operation shaft 91 The 60 spools 93 and the spool 94 of the variable relief valve 61 are configured to slide. The spool 94 of the variable relief valve 61 is pressed by the cam 92 with the passive member 95 provided at one end of the spool 94 as the operation amount in the left-right direction from the straight advance position of the control lever 18 increases. The relief pressure for the left and right side clutch brake units 31 is increased by a large displacement in the direction against the above action. And when the passive member 95 contact | abuts to the valve seat part 87D formed in the valve case 87, it is comprised so that the relief pressure with respect to the left and right side clutch brake units 31 may become the maximum.

  From this configuration, by operating the control lever 18 and adjusting the pressure so that a predetermined maximum pressure is obtained in a state where the passive member 95 is in contact with the valve seat portion 87D, for example, both the left and right sides of the control lever 18 are adjusted. As compared with the case of adjusting the pressure so that the same pressure can be obtained at the same operating angle while measuring the operating angle of the angle, the labor required for adjusting the pressure is greatly reduced, and the operating direction of the control lever 18 is changed. In addition, it is possible to effectively suppress the occurrence of variation in the relationship between the operation amount from the straight position of the control lever 18 and the relief pressure with respect to the side clutch brake unit 31. This variation can be more effectively suppressed by increasing the processing accuracy of the contact surface between the passive member 95 and the valve seat portion 87D.

  As shown in FIG. 12, two stud bolts 97 are provided at the mounting position of the valve unit 63 in the transmission case 21. Thus, when the valve unit 63 is bolted to the transmission case 21, the gasket 98 interposed between the transmission case 21 and the valve case 87 of the valve unit 63 can be supported by the two stud bolts 97. It is possible to prevent the gasket 98 from falling off or being displaced. As a result, the valve unit 63 can be easily attached to the transmission case 21 via the gasket 98.

  The working vehicle hydraulic device according to the present invention includes a hydraulic pipe that forms an oil passage extending between a transmission case and a valve case disposed in front of the transmission case. It can be applied to corn harvesters, tractors, transport vehicles, etc.

DESCRIPTION OF SYMBOLS 9 Boarding operation part 21 Transmission case 21G Expansion part 23 Side panel 40 Side clutch 75 Hydraulic pump 79 Oil supply path 80 Oil path 81 Oil path 84 Supply hydraulic pipe 85 1st hydraulic pipe (hydraulic pipe)
86 Second hydraulic pipe (hydraulic pipe)
87 Valve case 87A Supply connection (connection)
87B 1st connection part (connection part)
87C 2nd connection part (connection part)
88 Elbow 89 Refueling pipe 89A Refueling port A Traveling device B Continuously variable transmission

Claims (13)

A transmission case, a valve case disposed in front of the transmission case, and a hydraulic pipe that forms an oil passage extending between the transmission case and the valve case,
The said valve case is provided with the connection part for at least 1 piping on either of the up-and-down, right-and-left each side surface, The hydraulic device of the working vehicle comprised so that the said hydraulic pipe might be connected to the said connection part.   2. The hydraulic device for a work vehicle according to claim 1, wherein the valve case includes the connection portion on one or both of a left side surface and a right side surface thereof.   The hydraulic device for a work vehicle according to claim 1, wherein the valve case includes the connection portion on an upper surface thereof. The transmission case includes the valve case at a position biased to the left or right side of the front surface thereof,
2. The hydraulic device for a work vehicle according to claim 1, wherein the valve case includes the connection portion on an upper surface thereof and a left and right side surface located on a side opposite to the bias side.   The hydraulic device for a work vehicle according to any one of claims 1 to 4, wherein the connecting portion is configured to be able to connect the hydraulic pipe from above.   The work vehicle according to claim 2 or 4, wherein the connection portion provided on one or both of the left side surface and the right side surface of the valve case has an elbow so that the hydraulic pipe can be connected from above. Hydraulic system. The transmission case includes hydraulic left and right side clutches that intermittently transmit power to the left and right traveling devices,
The hydraulic pipe includes a first hydraulic pipe for the left side clutch and a second hydraulic pipe for the right side clutch,
The work valve according to any one of claims 1 to 6, wherein the valve case includes a first connection part for a first hydraulic pipe and a second connection part for a second hydraulic pipe as the connection part. Hydraulic device. A supply hydraulic pipe that forms an oil supply path extending from the hydraulic pump to the valve case;
The hydraulic device for a work vehicle according to any one of claims 1 to 7, wherein the valve case includes a supply connection portion that enables connection of the supply hydraulic pipe as one of the connection portions. . The transmission case includes a bulging portion that bulges forward,
The said valve case is arrange | positioned in the site | part different from the said bulging part in the said transmission case, and was set as the structure which does not protrude ahead from the front end of the said bulging part. Car hydraulic system. The transmission case is equipped with a continuously variable transmission on the outer surface of the upper portion thereof, and includes an oil supply pipe that enables oil supply into the transmission case,
The continuously variable transmission has an upper end located above the upper end of the transmission case,
The hydraulic device for a work vehicle according to any one of claims 1 to 9, wherein the oil supply pipe extends upward such that an oil supply port at an upper end thereof is positioned above an upper end of the continuously variable transmission. The transmission case is equipped with a continuously variable transmission on the outer surface of the upper portion thereof, and includes an oil supply pipe that enables oil supply into the transmission case,
The hydraulic device for a work vehicle according to any one of claims 1 to 10, wherein the oil supply pipe extends upward in an inclined posture in which an oil supply port at an upper end thereof is separated from the continuously variable transmission. The transmission case includes an oil supply pipe that enables oil supply to the inside thereof,
The hydraulic device for a work vehicle according to any one of claims 1 to 11, wherein the oil supply pipe extends upward in an inclined posture toward an upper front side of the transmission case. The transmission case includes an oil supply pipe that enables oil supply to the inside thereof,
13. The fuel supply pipe according to claim 1, wherein the fuel supply pipe is located on a lateral outer side of a side panel provided in a boarding operation unit, and extends upward so that a fuel supply port at an upper end thereof is located near an upper end of the side panel. The hydraulic device for a work vehicle according to any one of the above.

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