JP2005264981A - Control valve device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize the thickness in a lateral direction of a device, and to facilitate maintenance by molding the device with a single member and changing the layout of valves. <P>SOLUTION: The control valve device 69 fixed on one side surface of a housing 1, comprises an on/off valve 70 for controlling the operation of a forward/backward switching device 10, a proportional valve 71, a main relief valve 72, and an adjusting valve 73. On an attaching member 81 formed by a single platy member, these valves are disposed on the substantially same plane that is parallel with an abutting place with the front portion housing 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control valve device for a work vehicle, and more particularly to a technique for changing the layout of valves to make the configuration compact and facilitating replacement and maintenance of the valves.

  A work vehicle such as a tractor is provided with a forward / reverse switching device, a high / low speed switching device (transmission device), or the like in a clutch housing or a transmission case (hereinafter referred to as an airframe housing). In particular, the forward / reverse switching device is controlled to move forward and backward using a forward hydraulic clutch and a backward hydraulic clutch, and the traveling direction of the work vehicle is switched. A control valve device in which each valve for controlling the operation of the forward / reverse switching device is inserted is called a control valve device, and one arranged on one side surface of a machine housing is known (for example, Patent Document 1 and Patent Document 2). reference).

  In Patent Document 1 and Patent Document 2, the structure of a control valve device as shown in FIG. 9 is disclosed. That is, the control valve device 269 is inserted into the opening 251 on one side wall of the front housing 201 of the body housing and fixed to the front housing 201. The control valve device 269 has a plate member 269a that runs along the outer surface of the side wall of the front housing 201, an outer housing member 269b that runs along the outer surface of the plate member 269a via a thin partition plate 250, and an inner surface of the plate member 269a. It is comprised from the several member which consists of the internal housing member 269c located in the front housing 201 along the front.

  The plate member 269a is screwed by an outer housing member 269b and a bolt through the partition plate 250, and an inner housing member 269c is screwed inside the plate member 269a. Among these members, the plate member 269a is mainly used for forming an oil passage, and a connecting oil passage between the plate member 269a and the external housing member 269b is formed in the partition plate 250. The connection between the oil passage in the plate member 269a and the oil passage in the internal housing member 269c is configured such that the corresponding oil passages are arranged facing each other.

  A housing portion 269d is formed on the outer surface of the external housing member 269b of the control valve device 269, and a main relief valve 271 and a direction switching valve 270 for controlling the flow rate of hydraulic oil are arranged vertically in the housing portion 269d. However, it is provided along the front-rear direction. A relief valve 272, a flow rate control valve 273, an oil passage cutoff valve 274, and the like are disposed along the front-rear direction in the internal housing member 269c.

  As described above, since the conventional control valve device is attached separately from the forward / reverse transmission device or the like, it is easy to assemble the forward / reverse switching device in the body housing. In addition, the control valve device itself can be easily mounted because it can be fixedly attached to the side wall of the body housing by a simple fixing means such as a bolt.

JP-A-8-156620 JP-A-8-277802

  However, the conventional control valve device has a configuration in which the valves are arranged in the left-right direction of the work vehicle so that the thickness in the left-right direction is large, and since it is configured by a plurality of members, it is configured compactly. It was difficult. The fuselage frame is disposed in the front-rear direction at the left and right center of the platform, and fuel tanks are disposed on the left and right sides of the fuselage frame. The control valve device is disposed on one side wall of the body frame and is located in the gap between the fuel tank and the body frame. If the thickness of the control valve device in the left-right direction was large, the tank capacity of the fuel tanks arranged on the left and right sides of the fuselage frame could not be increased.

  Further, in order to remove the valves from the control valve device for maintenance or replacement, it is necessary to once remove the control valve device from the body frame and take out a valve or the like disposed therein. Since the fuel tank is arranged in the left and right direction of the fuselage frame, such work is troublesome, and even the valves arranged on the side surface of the control valve device and along the front and rear direction of the fuselage frame are removed. That wasn't always easy.

  Furthermore, since the control valve device disclosed in Patent Document 1 and Patent Document 2 is provided with an opening provided on one side wall of the machine body frame, the manufacturing process for separately forming the opening is complicated, and the manufacturing cost is increased. It was hanging.

  Therefore, the present invention relates to a control valve device for a work vehicle, which solves the above-described conventional problems. The thickness of the device in the left-right direction is minimized by molding with a single member and changing the arrangement of valves. The purpose is to make the structure compact so that it can be easily maintained.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, according to the first aspect of the present invention, there is provided a control valve device for a work vehicle having a plurality of valves for controlling the operation of the forward / reverse switching device and fixed to one side surface of the body housing. In the formed mounting member, the valves are arranged on a substantially plane parallel to the contact plane with the body housing.

  In a second aspect, the valves according to the first aspect are arranged in parallel or perpendicular to each other.

  In Claim 3, in Claim 1 or Claim 2, the valves include an ON / OFF valve and a proportional valve for controlling supply / discharge of hydraulic oil to / from the forward / reverse switching device. An OFF valve and a proportional valve are arranged so that they can be inserted and removed from below.

  According to a fourth aspect of the present invention, in the first or second aspect, the valves include at least a relief valve and an adjustment valve that control supply and discharge of lubricating oil to and from the forward / reverse switching device. The valve is disposed so as to be insertable / removable from the front / rear of the airframe housing.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, hydraulic oil pressure detection means for the forward / reverse switching device is detachably provided from the lower side.

  As effects of the present invention, the following effects can be obtained.

  Since it is set as the structure shown in Claim 1, the thickness of the left-right direction of a control valve apparatus can be comprised compactly, and the left-right space of an airframe frame can be ensured large. Therefore, maintainability can be improved and heat dissipation can also be improved. In addition, the number of parts can be reduced and the manufacturing cost can be reduced.

  Since the structure shown in claim 2 is adopted, the thickness of the control valve device in the left-right direction can be made smaller. Further, these valves have a large mounting length of the electromagnetic valve and an opening with the oil passage. Therefore, it is possible to secure a space for insertion / removal by arranging the control valve device substantially vertically.

  Since it is set as the structure shown in Claim 3, the maintenance and replacement | exchange of valves become easy from the downward direction of a working vehicle in priority to the replacement frequency of a proportional valve or an ON / OFF valve.

  Since the configuration shown in claim 4 is adopted, a layout with a minimum volume of the control valve device is possible.

  Since it is set as the structure shown in Claim 5, the maintenance and replacement | exchange of a pressure measurement means and the measurement of various pressures become easy.

Next, the best mode for carrying out the invention will be described.
FIG. 1 is a schematic partially developed longitudinal side view showing an overall configuration of a transmission mechanism of a tractor according to an embodiment of the present invention, and FIG. 2 is a hydraulic circuit disposed in the tractor and control valve device of FIG. 3 is a front perspective view of the control valve device according to the present invention, FIG. 4 is a partially developed side sectional view of the control valve device disposed on the outer wall of the body frame of the tractor, and FIG. 4 is a partially developed plan view of FIG. 4 showing the filter, FIG. 6 is a cross-sectional view taken along arrow AA of FIG. 3, FIG. 7 is a rear view of the control valve device, and FIG.

First, an overall configuration of a tractor equipped with an oil supply device according to the present invention will be described.
As shown in FIG. 1, the tractor body housing includes a front housing 1, an intermediate housing 2, and a rear housing 3 that are connected in the front-rear direction. The front housing 1 has an integral supporting wall portion 1a at an intermediate portion, and is attached to and supported by the front housing 1 at a position where the inside of the front housing 1 on the rear side of the supporting wall portion 1a is roughly divided into two front and rear. 1 has a second bearing frame 5 attached to and supported by the rear end of the front housing 1. The second bearing frame 5 may be attached to and supported by the front end of the intermediate housing 2.

  The intermediate housing 2 has a supporting wall portion 2a integral with the intermediate portion, and the rear housing 3 has a front wall 3a, a support wall 3b at the intermediate portion, and a rear lid 3c for closing the opening at the rear end. An engine flywheel 6 is positioned at the foremost part in the front housing 1, and a driving shaft 8 connected to the engine flywheel 6 via a buffer joint 7 is provided in the front housing 1.

  The traveling transmission mechanism is configured by connecting a forward / reverse switching device 10, a high / low speed switching device 13, a main transmission 16 and a sub transmission 19 in series. The forward / reverse switching device 10 is disposed between the support wall 1a and the first bearing frame 4 between the driving shaft 8 and the driven shaft 9 disposed therebelow. The high / low speed switching device 13 is arranged on the extension line of the driven shaft 9 between the first bearing frame 4 and the second bearing frame 5 and is an extension of the drive shaft 11 and the driving shaft 8 connected to the driven shaft 9. It is arranged between the hollow driven shaft 12 arranged on the line. The main transmission 16 is disposed on the extension line of the driven shaft 12 and is connected between the hollow drive shaft 14 connected to the driven shaft 12 and the driven shaft 15 arranged on the extension line of the drive shaft 11. Arranged in the front half. The auxiliary transmission 19 includes a hollow counter shaft 17 disposed in the rear half of the intermediate housing 2 between the driven shaft 15 and the propeller shaft 18 disposed on the extension line thereof, and disposed on the extension line of the drive shaft 14. It is configured as follows.

  The rear end of the propeller shaft 18 is provided with a small bevel gear 21 that extends into the rear housing 3 and meshes with an input bevel gear 20 of a differential (not shown) for left and right rear wheels. A front wheel driving force take-out case 22 is attached to the bottom of the intermediate housing 2, and the propeller shaft 18 is connected to a front wheel driving force take-out shaft 23 supported by the take-out case 22 via a front wheel driving clutch 24. .

  The transmission mechanism of the PTO system is such that a transmission shaft 25 penetrating the hollow driven shaft 12, the drive shaft 14 and the counter shaft 17 is connected to the driving shaft 8 at its front end and connected to the rear end of the transmission shaft 25. A PTO clutch 28 is disposed between a transmission shaft 26 provided in the rear housing 3 and another transmission shaft 27 disposed on the extension line thereof. Further, a PTO transmission 30 having three speeds is provided between the transmission shaft 27 and a PTO shaft 29 disposed below and extending rearward from the rear lid 3c. On the upper surface of the rear housing 3, a hydraulic lift device 33 including left and right lift arms 33 a for raising and lowering a working machine (not shown) driven by the PTO shaft 29 is installed.

  In the forward / reverse switching device 10, two gears 34 and 35 are loosely arranged on the driving shaft 8, and two gears 36 and 37 are fixed on the driven shaft 9. Of these, the gears 34 and 37 are meshed directly, and the gears 35 and 37 are meshed via an intermediate idler gear (not shown). A forward hydraulic clutch 40F and a reverse hydraulic clutch 40R are disposed on the driving shaft 8 between the gears 34 and 35.

  Each of the forward hydraulic clutch 40F and the reverse hydraulic clutch 40R is energized by supporting a plurality of friction elements arranged alternately on gears and clutch cylinders (not shown) in a slidable and relatively non-rotatable manner. The piston is moved to the direction of the friction element by the action of hydraulic pressure, and is configured as a known friction multi-plate type that obtains clutch engagement. Then, by engaging the forward hydraulic clutch 40F and coupling the gear 34 to the driving shaft 8, the driven shaft 9 is rotated in the vehicle forward direction, and the reverse hydraulic clutch 40R is engaged and the gear 35 is moved to the driving shaft 8. As a result, the driven shaft 9 is rotated in the vehicle reverse direction.

  In the high / low speed switching device 13, two gears 43 and 44 are loosely arranged on the drive shaft 11 connected to the driven shaft 9 by using the boss portion of the gear 36, and on the driven shaft 12. Two gears 45 and 46 are fixed to each other. The gears 43 and 44 and the gears 45 and 46 are meshed with each other. On the drive shaft 11, a high speed hydraulic clutch 48 </ b> H and a low speed hydraulic clutch 48 </ b> L that share a clutch cylinder fixed on the drive shaft 11 are disposed between the gears 43 and 44.

  Each high-speed hydraulic clutch 48H supports a plurality of friction elements arranged alternately on the boss portion of the gear 43 and the clutch cylinder so as to be slidable and relatively non-rotatable, and the urged piston is hydraulically actuated. It is constituted by a known friction multi-plate type that moves in the direction of the friction element to obtain clutch engagement. In particular, the low speed hydraulic clutch 48L supports a plurality of friction elements arranged alternately on the boss portion of the gear 44 and the clutch cylinder so as to be slidable and relatively non-rotatable. This is a so-called spring hydraulic oil type friction multi-plate clutch that is moved in the direction of the friction element by the urging force of the disc spring to obtain clutch engagement. A known technique can be used for the structure of the spring hydraulic oil type friction multi-plate clutch, and detailed description of the structure is omitted.

  In the main transmission 16, four gears 49, 50, 51, 52 are fixed on the drive shaft 14, and four gears 53, 54, 55, 56 are loosely fitted on the driven shaft 15. ing. Among these gears, the corresponding ones are meshed, and two multiple synchronous clutches 57 and 58 are disposed on the driven shaft 15 between the gears 53 and 54 and between the gears 55 and 56, and the gears 53, 54 and 55 are arranged. -It is configured to obtain a 4-speed shift by selectively coupling 56 to the driven shaft 15.

  In the auxiliary transmission device 19, the counter shaft 17 is speed-reduced and connected to the driven shaft 15 through a train of reduction gears 59 and 60, and two gears 61 and 62 are fixed on the counter shaft 17. Among these, the gear 64 connected via the reduction gear mechanism 63 is disposed outside the counter shaft 17 with respect to the gear 62 on the small diameter side. A shift gear 65 that can selectively mesh with the gears 64 and 62 is loosely fitted on the propeller shaft 18, and the position where the shift gear 65 is coupled to the propeller shaft 18 and the propeller shaft 18 are A double clutch 66 that is operated to a position that is directly connected to the driven shaft 15 is provided. By configuring in this way, the auxiliary transmission 19 is 1st speed by meshing the gears 64 and 65, 2nd speed by meshing the gears 62 and 65, 3rd speed by meshing the gear 66 with the propeller shaft 18, and By directly coupling the propeller shaft 18 to the driven shaft 15, each of the four speeds is selectively caused to the propeller shaft 18.

  As shown in FIGS. 2 to 4, a control valve device 69 is disposed on the attached surface on the outer surface of one side wall of the front housing 1. Valves related to the forward / reverse switching device 10 are inserted in the control valve device 69, and the hydraulic pressure of the forward hydraulic clutch 40F of the forward / reverse switching device 10 is switched as the valves. The forward ON / OFF valve 70F to be controlled, the reverse ON / OFF valve 70R to switch and control the hydraulic pressure supply / discharge of the reverse hydraulic clutch 40R, the forward ON / OFF valve 70F, and the reverse ON / OFF valve 70R A proportional valve 71 that controls the supply and discharge of hydraulic oil, a main relief valve 72 that sets the hydraulic pressure to the forward / reverse switching device 10, an adjustment valve 73, and the like are disposed. Details of the layout of these valves will be described later.

First, an outline of the control valve device 69 will be described below.
Referring to the hydraulic circuit diagram shown in FIG. 2, the control valve device 69 first includes a forward ON / OFF valve 70 </ b> F for switching and controlling the hydraulic pressure supply / discharge of the forward hydraulic clutch 40 </ b> F of the forward / reverse switching device 10, and the backward hydraulic pressure. A reverse ON / OFF valve 70R for switching and controlling the hydraulic pressure supply / discharge of the clutch 40R is disposed. An oil pump 75 for supplying hydraulic oil to the forward hydraulic clutch 40F and the reverse hydraulic clutch 40R is configured as an inscribed internal tooth type with the driving shaft 8 as a pump shaft, and is mounted on the front surface of the support wall portion 1a. Has been. The oil pump 75 sucks oil from the oil reservoir 76 in the machine frame through the strainer 77 through the filter 78. A line filter 79 is disposed at the discharge port of the oil pump 75, and a bypass valve 79a is connected so as to be parallel to the line filter 79, and hydraulic oil is sent from the oil pump 75 at a constant pressure. I am doing so.

  Here, the details of the line filter 79 will be described. As shown in FIGS. 4 and 5, an oil discharge passage 38 from the oil pump 75 is formed in the support wall portion 1a, and the oil discharge passage 38 is formed. Is communicated with a through-hole 86 that is opened from the support wall 1a to the front end of the control valve device 69 in the left-right direction. A line filter 79 is inserted into the through-hole 86, and the line filter 79 is inserted into the through-hole 86 by a coil spring 88 having a base end received by a screw plug 87 screwed into the control valve device 69 so as to close the through-hole 86. The inside of the hole 86 is urged so as to be movable. The through hole 86 communicates with a pump port 89 formed in the control valve device 69.

  When the line filter 79 becomes clogged with use and the pressure difference between before and after increases to a certain value, the oil pressure acting on the inner end of the line filter 79 moves against the urging force of the coil spring 88, and the oil discharge passage 38. And the pump port 89 are directly connected. For this reason, the line filter 79 acts as a bypass valve when clogged, the supply of oil to the forward hydraulic clutch 40F and the reverse hydraulic clutch 40R due to filter clogging is insufficient, or the oil pump 75 is overloaded. I do not take it.

  The oil from the oil pump 75 is transferred from the through hole 86 to the oil passage 80 formed in the control valve device 69 through the pump port 89. The oil passage 80 communicates with a proportional valve 71, a forward electromagnetic pilot switching valve 82F, a reverse electromagnetic pilot switching valve 82R, and a regulating valve 73 for the forward ON / OFF valve 70F and the reverse ON / OFF valve 70R. .

  The proportional valve 71 includes an electromagnetic pilot switching valve 83 and a pilot switching valve 84, and hydraulic oil from the oil passage 80 passes through the filters 85 and 85, and the electromagnetic pilot switching valve 83 and the pilot switching in the proportional valve 71. Each is transferred to a valve 84. The electromagnetic pilot switching valve 83 has a closed position for blocking the oil passage and an open position for opening, and receives pressure oil upstream of the electromagnetic pilot switching valve 83 in the valve spring and the pilot oil passage to the closed position. The solenoid 83a is energized and can be switched from the opposite side of the valve spring to the open position.

  The pilot switching valve 84 has a closed position for blocking the oil passage and an open position for opening, and is biased to the closed position by receiving the valve spring and the downstream pressure oil. The pilot switching valve 84 communicates with the pilot switching valves 92F and 92R of the forward ON / OFF valve 70F and the reverse ON / OFF valve 70R via the oil passage 90. When the solenoid 83a is operated to switch the electromagnetic pilot switching valve 83 to the open position, the hydraulic oil is transferred into the electromagnetic pilot switching valve 83, and the pilot switching valve 84 is moved to the open position via the pilot oil passage. Switched. By providing the electromagnetic pilot switching valve 83, pilot switching is performed when a large flow rate of hydraulic fluid is transferred from the oil passage 80 to the oil passage 90 via the pilot switching valve 84 or when the flow rate is relatively low. The impact at the time of switching of the valve 84 can be reduced.

  Here, the flow rate of the working oil in this embodiment is controlled by a position sensor 96 a disposed near the rotation shaft of the clutch pedal 96 and a pressure switch 97 connected to the oil passage 90. The proportional valve 71 detects the rotation of the clutch pedal 96 by the position sensor 96a, opens and closes the electromagnetic pilot switching valve 83 in proportion to this rotation, and sends the pilot oil to the operating portion of the pilot switching valve 84. The pilot switching valve 84 is opened and closed to control the flow rate of the hydraulic fluid flowing to the forward / reverse switching device 10 via the pilot switching valve 84. That is, when the clutch pedal 96 is depressed by the maximum stroke, the pilot switching valve 84 is in the closed position and does not flow to the forward / reverse switching device 10, but when the clutch pedal 96 is gradually released, it is proportional to the depression amount. The proportional valve 71 (pilot switching valve 84) is opened, and hydraulic oil flows from the oil passage 80 to the oil passage 90 via the proportional valve 71. When the foot is released from the clutch pedal 96, the hydraulic fluid flows to the forward / reverse switching device 10 on the forward or reverse operation position side. At this time, the oil pressure of the oil passage 90 on the outlet side of the proportional valve 71 is detected by a pressure switch 97 as pressure detecting means, and it is detected whether an appropriate pressure is being output.

  Further, since the operation of depressing and releasing the clutch pedal 96 varies depending on the operator, the sudden operation damages the clutch or the like and leads to a sudden start. Therefore, the controller 98 determines the clutch pedal 96 based on the rotation angle of the clutch pedal 96. However, when the change of the value of the position sensor 96a is calculated by the controller 98 and the clutch pedal 96 is suddenly released, the solenoid 83a is gradually switched so that the work vehicle does not start suddenly. The pressure of the hydraulic oil in the oil passage 90 is controlled so that the oil passage 80 and the oil passage 90 are gradually communicated.

  The forward ON / OFF valve 70F and the reverse ON / OFF valve 70R are composed of a forward electromagnetic pilot switching valve 82F and a reverse electromagnetic pilot switching valve 82R, a forward pilot switching valve 92F, and a reverse pilot switching valve 92R. Has been. The hydraulic oil from the oil pump 75 is transferred from the oil passage 80 to the forward electromagnetic pilot switching valve 82R and the reverse electromagnetic pilot switching valve 82R through the filters 95 and 95, respectively. Further, the hydraulic oil from the proportional valve 71 is transferred to the forward pilot switching valve 92F and the reverse pilot switching valve 92R through the oil passage 90, respectively.

  The forward electromagnetic pilot switching valve 82F (reverse electromagnetic pilot switching valve 82R) has a closed position for blocking the oil passage and an open position for opening, and is urged to the closed position by a valve spring, so that the solenoid 82a (82a ) Is configured to be switchable from the opposite side of the valve spring to the open position. When the solenoid 82a (82a) is operated and the forward electromagnetic pilot switching valve 82F (reverse electromagnetic pilot switching valve 82R) is switched to the open position, the forward electromagnetic pilot switching valve 82F (reverse electromagnetic pilot switching valve 82R) The hydraulic fluid is transferred to the forward pilot switching valve 92F (reverse traveling pilot switching valve 92R) through the pilot oil passage.

  The forward pilot switching valve 92F (reverse pilot switching valve 92R) includes a neutral position N for disconnecting the hydraulic clutch 40F (40R) and a forward operation position F (reverse operation position R for selectively operating the hydraulic clutch 40F (40R). ), And is biased to the neutral position N by receiving pressure oil from the valve spring. The forward pilot switching valve 92F (reverse pilot switching valve 92R) is communicated with the hydraulic clutches 40F and 40R via an oil passage 93 (oil passage 94). Thus, by providing the forward electromagnetic pilot switching valve 82F (reverse electromagnetic pilot switching valve 82R), the forward pilot switching valve 92F (reverse pilot is moved from the oil path 90 to the oil path 93 (oil path 94). When a large flow rate of hydraulic fluid is transferred through the switching valve 92R) or when the flow rate is relatively low, the impact when switching the forward pilot switching valve 92F (reverse pilot switching valve 92R) is reduced. Can be made.

  The solenoid 82a (82a) of the forward electromagnetic pilot switching valve 82F (reverse electromagnetic pilot switching valve 82R) is switched by a forward / reverse switching lever (not shown). For example, when the forward / reverse switching lever is in the forward position. The solenoid 82a of the forward electromagnetic pilot switching valve 82F is actuated, and the forward electromagnetic pilot switching valve 82F is switched to the open position. Then, the forward pilot switching valve 92F is switched to the forward operation position F via the pilot oil passage, and the oil passage 90 is communicated with the oil passage 93 via the forward pilot switching valve 92F. When the forward / reverse switching lever is in the reverse position, the solenoid 82a of the reverse electromagnetic pilot switching valve 82R is operated, and the reverse pilot switching valve 92R is switched to the reverse operation position R through the pilot oil passage.

  The main relief valve 72 is disposed in the middle of the oil passage 80 on the downstream side of the line filter 79, and the relief oil passage 99 from the main relief valve 72 is guided in the directions of the hydraulic clutches 40F and 40R. Then, lubricating oil is supplied to discs (not shown) of the hydraulic clutches 40F and 40R. A regulating valve 73 is disposed in the middle of the oil passage 99, and the lubricating oil transferred from the main relief valve 72 to the oil passage 99 is drained to the oil reservoir 76 in the fuselage housing by the regulating valve 73. The flow rate of the lubricating oil supplied to the oil passage 99 is adjusted by the differential pressure between the main relief valve 72 and the adjustment valve 73.

  The shuttle valve 74 is disposed on the downstream side of the oil passage 99, and is urged by a valve spring from both sides at a neutral position I that closes the oil passage 99, and is connected to the oil passage 93 and the oil passage 94. In response to the oil pressure of the pilot oil passages 100 and 100, the oil passage 99 is switched to the open position II. That is, when the shuttle valve 74 receives the oil pressure of the oil passage 93 transferred from the forward ON / OFF valve 70F via the pilot oil passage 100, the shuttle valve 74 is operated and switched from the neutral position I to the open position II (FIG. 2 on the right). On the other hand, when the oil pressure of the oil passage 94 transferred from the reverse ON / OFF valve 70R is received via the pilot oil passage 100, the operation is switched from the neutral position I to the open position II (left side in FIG. 2). .

  The oil passage 101 communicated with the shuttle valve 74 is drilled over the control valve device 69 and the body frame (not shown), and branches in two directions on the downstream side, respectively, the forward hydraulic clutch 40F and the reverse drive. The hydraulic clutch 40R is in communication. A forward switching valve 102F and a reverse switching valve 102R are disposed in the middle of the branched oil passages 101 and 101, respectively. The forward switching valve 102F (reverse switching valve 102R) is biased to a throttle position that restricts the flow rate of the lubricating oil in the oil passage 101 by a valve spring, and the forward ON / OFF valve 70F is passed through the pilot oil passage. When the oil pressure of the oil passage 93 (oil passage 94) transferred from the reverse ON / OFF valve 70R is received, the oil pressure is switched to the open position and the lubricating oil is transferred.

  The lubricating oil transferred from the main relief valve 72 through the relief oil passage 99 is transferred to the oil passage 101 regardless of whether the shuttle valve 74 is advanced or reverse when the shuttle valve 74 is opened by the oil pressure of the oil passage 93 and the oil passage 94. Further, when the forward switching valve 102F and the reverse switching valve 102R are released by the oil pressure of the oil passage 93 and the oil passage 94, the forward hydraulic clutch 40F is mainly used when the work vehicle is moving forward, or the The lubricating oil is supplied to the reverse hydraulic clutch 40R. Thus, since the shuttle valve 74 and the switching valves 102F and 102R that are switched by receiving the hydraulic pressure of the hydraulic oil through the pilot oil passage are disposed, the hydraulic clutch 40F is controlled while controlling the flow rate according to the driving of the work vehicle.・ Lubricating oil can be supplied to 40R.

Next, the arrangement of the valves in the control valve device 69 will be described in detail below.
As shown in FIGS. 3 to 8, the mounting member 81 for mounting the valve of the control valve device 69 is formed by a single plate-like member having a substantially rectangular shape in side view, The abutment surface of the front frame 1 is formed so as to be a substantially vertical plane in the front-rear direction, and is firmly attached to the outer surface of the left side wall of the front housing 1 of the body frame. By configuring the control valve device 69 with a single plate-like mounting member 81, the thickness of the control valve device 69 in the left-right direction with respect to the body frame can be reduced. Further, the manufacturing cost can be reduced by reducing the number of parts. On the contact surface side of the control valve device 69, the oil passage described above is opened and opened in the contact surface so that the oil supplied from the oil pump 75 is filled and does not leak outside. It is installed.

  The outer side surface of the mounting member 81 of the control valve device 69 is formed in an uneven planar shape, and as valves, the forward ON / OFF valve 70F, the reverse ON / OFF valve 70R, the proportional valve 71, the main relief valve 72, and the regulating valve 73, the shuttle valve 74, etc. are inserted so that insertion / removal is possible. In the present embodiment, each valve is configured to be disposed on substantially one plane parallel to the contact plane between the mounting member 81 and the front housing 1. With such an arrangement, the thickness of the control valve device 69 in the left-right direction can be further reduced, and the tank capacity of fuel tanks (not shown) arranged on the left and right of the body frame can be increased. In the case where the fuel tank is not disposed, a large space can be provided between the outer surface of the control valve device 69 and the body side member such as a step. Further, a hydraulic circuit can be drilled in a compact manner in the attachment member 81 or on the side surface on the machine body side.

  A plurality of mounting holes 104 for inserting the proportional valve 71, the forward ON / OFF valve 70F and the like are formed in the lower surface, front surface, or rear surface of the mounting member 81, and the lower surface 69a of the control valve device 69 is formed. The mounting holes 104, 105, and 106 for attaching the proportional valve 71, the forward ON / OFF valve 70F, and the reverse ON / OFF valve 70R as valves are drilled upward from the bottom, respectively, and can be inserted and removed. It is attached. Further, through holes for fastening bolt screws for fixing to the side wall of the front housing 1 are formed in the left-right direction, and bosses 103, 103... Are formed for reinforcement.

  The main relief valve 72 and the adjustment valve 73 are arranged in parallel in the vertical direction, and the proportional valve 71, the forward ON / OFF valve 70F and the reverse ON / OFF valve 70R are arranged in parallel in the front-rear direction, respectively. Are arranged so as to be substantially orthogonal to the proportional valve 71, the forward ON / OFF valve 70F, and the reverse ON / OFF valve 70R. In other words, as viewed from the approximate center of the control valve device 69, the valves are arranged radially, and the valves are arranged in parallel or perpendicular to each other. By adopting such an arrangement configuration, an optimum arrangement layout for reducing the size of the control valve device 69 is possible, and it is easy to remove each other. Furthermore, these valves have a large attachment length of the electromagnetic valve and need to provide a large number of openings with the oil passage, so that a space for inserting and removing the valves can be secured.

  The control valve device 69 is provided with mounting holes 104, 105, and 106 for forward ON / OFF valve 70F, reverse ON / OFF valve 70R, and proportional valve 71. The mounting holes 104, 105, and 106 are substantially vertical from the lower side (X direction in FIG. 3) to the upper side of the control valve device 69, and the mounting holes 104, 105, and 106 are substantially on the same plane in the rear view. It is perforated so that it may be located in. Then, the proportional valve 71 is provided in the mounting hole 104, the forward ON / OFF valve 70F is provided in the mounting hole 105, and the reverse ON / OFF valve 70R is provided in the mounting hole 106. -It is inserted in 105,106. The mounting holes 104, 105, and 106 are respectively provided with openings 104a, 105a, and 106a that communicate with the oil passages formed in the control valve device 69, and hydraulic oil from the oil pump 75 is supplied to the mounting holes 104, 105, and 106. Supplied to each valve.

  Since the proportional valve 71, the forward ON / OFF valve 70F and the reverse ON / OFF valve 70R can be inserted and removed from below the control valve device 69, the maintenance of these valves becomes easy. That is, the control valve device 69 is disposed on the outer surface of the front housing 1 disposed on the front side of the body frame disposed in the front-rear direction in the vehicle body. This is because it can be easily removed because it is open from the bottom of the work vehicle.

  As shown in FIG. 6, a pressure switch 97 as the pressure detecting means is detachably disposed in a mounting hole 107 drilled substantially vertically from the lower side to the upper side of the control valve device 69, for forward movement. Pressure measuring ports 111, 111... For inspecting and measuring the hydraulic pressure of the ON / OFF valve 70F, the reverse ON / OFF valve 70R, etc. are also formed on the lower surface side (X direction) of the control valve device 69. . Therefore, maintenance and replacement of the pressure switch 97 and measurement of various pressures can be easily performed.

  In the state where the proportional valve 71, the forward ON / OFF valve 70F, and the reverse ON / OFF valve 70R are disposed in the control valve device 69, when the control valve device 69 is disposed in the front housing 1, The leading ends of the proportional valves 71, the forward ON / OFF valve 70F, and the reverse ON / OFF valve 70R are all located above the lower end surface of the front housing 1, and do not protrude from the lower end surface of the front housing 1. Thus, damage to each proportional valve 71, forward ON / OFF valve 70F and reverse ON / OFF valve 70R is prevented (see FIG. 4).

  As shown in FIGS. 4 and 7, the mounting holes 108 and 109 of the main relief valve 72 and the regulating valve 73 are directed from the rear side (Y direction in FIG. 3) to the front, and the mounting holes The holes 108 and 109 are formed so as to be located on substantially the same plane in a plan view. In the mounting holes 108 and 109, the main relief valve 72 and the adjustment valve 73 in the mounting hole 109 are removably inserted into the mounting holes 108 and 109 from the rear of the control valve device 69, respectively. Yes. In the mounting holes 108 and 109, openings 108a and 109a communicating with oil passages formed in the control valve device 69 are formed, respectively, and hydraulic oil from the oil pump 75 is supplied to the valves. Yes.

  As shown in FIGS. 4 and 8, the mounting hole 110 of the shuttle valve 74 is drilled from the front side (Z direction in FIG. 3) to the rear side of the body frame. A shuttle valve 74 is removably inserted into the mounting hole 110 from the front of the control valve device 69 in the mounting hole 110. The mounting hole 110 has an opening 110 a communicating with an oil passage formed in the control valve device 69, and hydraulic oil from the oil pump 75 is supplied to the shuttle valve 74.

  As described above, the main relief valve 72, the adjustment valve 73, and the shuttle valve 74 can be inserted and removed from the front and rear directions of the control valve device 69. Therefore, the control valve device 69 can be easily replaced from the outside without disassembling. it can. Since these valves have a somewhat lower maintenance frequency than the proportional valve 71, the forward ON / OFF valve 70F, and the reverse ON / OFF valve 70R, the proportional valve 71, the forward ON / OFF valve 70F, and In order to give priority to the replacement of the reverse ON / OFF valve 70R, it is arranged along the longitudinal direction of the body frame. Nevertheless, this arrangement allows a layout that is small in the left-right direction of the body frame and that has the minimum volume of the control valve device 69.

  In addition, arrangement | positioning of valves is not limited to what was shown in FIG.3 and FIG.4, You may arrange | position so that an up-down position and a front-back position may differ. Moreover, the kind of valve | bulb etc. which are arrange | positioned is not limited to these.

The typical partially expanded vertical side view which shows the whole structure of the transmission mechanism of the tractor which concerns on one Example of this invention. The circuit diagram which shows the hydraulic circuit arrange | positioned by the tractor and control valve apparatus of FIG. The front perspective view of the control valve apparatus which concerns on this invention. The partial expanded side sectional view of the control valve apparatus arrange | positioned by the outer side wall of the body frame of a tractor. The partial expansion top view of FIG. 4 which shows a line filter. AA arrow sectional drawing of FIG. The rear view of a control valve apparatus. The front view of a control valve apparatus. The disassembled perspective view of the conventional control valve apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front housing 10 Forward / reverse switching device 69 Control valve device 70 ON / OFF valve 71 Proportional valve 72 Main relief valve 73 Adjustment valve 74 Shuttle valve

Claims (5)

In a control valve device for a work vehicle that has a plurality of valves for controlling the operation of the forward / reverse switching device and is fixed to one side surface of the machine housing,
To the mounting member formed by a single plate-like member,
A control bubble device for a work vehicle, characterized in that the valves are arranged on substantially one plane parallel to a contact plane with the body housing.   2. The control valve device for a work vehicle according to claim 1, wherein the valves are arranged in parallel or perpendicular to each other. The valves include at least an ON / OFF valve and a proportional valve for controlling supply / discharge of hydraulic oil to / from the forward / reverse switching device,
The control valve device for a work vehicle according to claim 1 or 2, wherein the ON / OFF valve and the proportional valve are arranged to be detachable from below. The valves include at least a main relief valve and a regulating valve that control supply and discharge of lubricating oil to and from the forward / reverse switching device,
The control valve device for a work vehicle according to claim 1 or 2, wherein the main relief valve and the adjusting valve are disposed so as to be insertable / removable from the front-rear direction of the body housing.   The control valve device for a work vehicle according to any one of claims 1 to 4, wherein pressure detecting means for operating oil to the forward / reverse switching device is detachably provided from below.

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