JP2009261304A - Device for controlling hydraulic pressure for lifting and lowering reaping device in combine harvester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a lowering speed of a reaping device to be changed by a labor-assisted operation of a lifting and lowering operation lever or the like, and to make the responsibility for immediately changing the lowering speed according to the operation of the lifting and lowering operation lever or the like good. <P>SOLUTION: The device for controlling the hydraulic pressure for lifting and lowering the reaping device is constituted as follows. A reaping electromagnetic selector valve 36 is installed in a reaping hydraulic passage 70 for feeding oil to a reaping lifting and lowering cylinder 37 for lifting and lowering the reaping device 1 from a hydraulic pump 12, and an electromagnetic changeable throttle valve 35 for regulating the lowering speed is installed in the returning side of the reaping electromagnetic selector valve 36. The electromagnetic changeable throttle valve 35 is constituted so that the electromagnetic changeable throttle valve may be held at the maximumly opened state when the reaping electromagnetic selector valve 36 is in the off state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a combine harvester lifting / lowering hydraulic control device.

A combine harvester lifting / lowering hydraulic control device is described in, for example, Japanese Patent Application Laid-Open No. 2002-21805.
This reaping device lifting hydraulic control device switches the supply amount to a supply oil path from the hydraulic pump to the lifting cylinder as a means for changing the lifting speed of the reaping device without using a conventional expensive high speed switching valve. A main electromagnetic control valve is arranged, a sub electromagnetic control valve and a variable throttle valve are arranged in the drain oil passage branched from the oil passage between the elevating cylinder and the main electromagnetic control valve, and the lifting speed of the reaping device is increased in two or three stages. It can be switched to a stage.
JP 2002-21805 A

  The reaping device lifting hydraulic control device is provided with a sub electromagnetic control valve and a constant variable throttle valve in the drain oil passage branched between the lifting cylinder and the main electromagnetic control valve. Therefore, the constant variable throttle valve must be adjusted in advance so that the desired lowering speed is obtained.

  Therefore, in the present invention, the lowering speed of the reaping device can be arbitrarily changed by hand operation of the elevating operation lever and the like, and the responsiveness that immediately changes the lowering speed according to the operation of the elevating operation lever and the like is improved. This is the issue.

The present invention takes the following technical means in order to solve the above-described problems.
That is, according to the first aspect of the present invention, the cutting electromagnetic switching valve (36) is provided in the cutting oil passage (70) for supplying oil from the hydraulic pump (12) to the cutting lift cylinder (37) that lifts and lowers the cutting device (1). And an electromagnetic variable throttle valve (35) for adjusting the lowering speed of the harvesting device (1) is provided on the return side of the harvesting electromagnetic switching valve (36). 36) A combine harvester lifting / lowering hydraulic control device characterized in that the control is performed so as to maintain the maximum open state when the switch 36 is turned off.

  In this configuration, when the cutting electromagnetic switching valve 36 is turned on and the current is gradually switched to the lowering side, the electromagnetic variable throttle valve 35 is in the maximum open state, so that the oil in the cutting lifting cylinder 37 quickly returns. The reaping device 1 starts to descend at a descending speed corresponding to the switching speed of the reaping electromagnetic switching valve 36.

  According to the second aspect of the present invention, the cutting electromagnetic switching valve (36) is provided in the cutting oil passage (70) for supplying oil from the hydraulic pump (12) to the cutting lift cylinder (37) that lifts and lowers the cutting device (1). In addition, an electromagnetic variable throttle valve (35) for adjusting the lowering speed of the cutting device (1) is provided on the return side of the cutting electromagnetic switching valve (36), and the electromagnetic variable throttle valve (35) is maximum when the cutting operation starts. The harvester lifting / lowering hydraulic control device for a combine harvester is characterized in that the control is performed so as to be held in an open state.

  In this configuration, when the cutting operation is started, the cutting device 1 is lowered at a lowering speed corresponding to the switching speed of the cutting electromagnetic switching valve 36.

  According to the first aspect of the present invention, the reaping device 1 starts to descend at a descending speed corresponding to the switching speed of the reaping electromagnetic switching valve 36. Therefore, the reaping electromagnetic switching valve 36 is switched by the elevating lever provided at the operator's hand. For example, the operation of dropping the harvesting device 1 by putting the combine into the field and lowering the harvesting device 1 can be quickly performed and the operation of lowering the harvesting device 1 after turning can be quickly performed, and the efficiency of the harvesting operation can be increased.

  According to the second aspect of the present invention, even if the electromagnetic variable throttle valve 35 is closed when the combine is moved, the throttle is opened to the maximum when the operation is started. If the switching operation is performed with the lifting lever provided at hand, the reaping device 1 can be quickly lowered, and the efficiency of the reaping work is improved.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall side view of a combine equipped with the present invention.

  The combine 11 includes a pair of left and right crawler travel devices 4, 4 at the bottom of the chassis 2, and a threshing device 6 is mounted on the chassis 2. The chassis 2 is attached to the crawler traveling devices 4 and 4 so as to be tilted to the left and right to roll or to be tilted to the front and back to pitch.

  The reaping device 1 is provided on a reaping frame 5 in which the front side of the threshing device 6 can be moved up and down around the pivot shaft 10 at the upper end at the foremost part of the chassis 2. The mowing apparatus 1 is located near the ground during the mowing work, and is moistened when turning or moving, and is raised to the maximum when traveling on the road to be separated from the ground. A cabin 7 on which the operator is boarded is provided on the front side of the right side of the threshing device 6, a grain tank 9 is provided on the rear side, and a grain discharge auger 8 for discharging the harvested grains in the grain tank 9 is undulated on the upper side of the threshing device 6. And it is provided to extend and contract.

  When harvesting grains such as rice and wheat, the operator gets on the cabin 7, moves the cutting device 1 near the ground and drives the left and right crawler traveling devices 4, 4 to move forward and harvests the cereal. It is cut by the apparatus 1, sent to the threshing apparatus 6, threshed and stored in the glen tank 8. When the grain in the Glen tank 8 is full, it approaches the truck that stops the harvesting of the grain and stops at the end of the road, and the grain tank in the grain tank 8 is removed from the grain tank by the grain discharge auger 8. To discharge.

  2 and 3, reference numeral 145 denotes a transmission case of a traveling device for a working machine such as a combine. A traveling hydraulic main transmission (hydrostatic transmission) 146 for shifting the traveling speed is provided at an upper position.

  Reference numeral 147 denotes an input pulley for inputting rotation from the engine to the traveling hydraulic main transmission 146, and reference numeral 148 denotes an output shaft of the traveling hydraulic main transmission 146, which serves as an input shaft for the transmission case 145. Reference numeral 149 denotes an auxiliary transmission shaft. The auxiliary transmission shaft 149 is provided with a gear group 150 so as to rotate integrally, and the gear group 150 selectively meshes with the gear 152 of the counter shaft 151. A center gear 154 is provided on the intermediate shaft 153 rotated by the counter shaft 151, and the center gear 154 is always meshed with a passive gear 156 fixed to the side clutch shaft 155.

  A side clutch gear 157 is slidably provided on the side clutch shaft 155, and a clutch pawl provided on the side clutch gear 157 is detachably engaged with an internal tooth of the passive gear 156 to form a left and right side clutch 158. . The configuration of the left and right side clutch 158 is arbitrary and is not limited to the embodiment.

The side clutch gears 157 mesh with the axle gears 160 provided on the left and right axles 159, respectively, and transmit the rotation to the axles 159.
Therefore, a differential mechanism 161 is provided in the vicinity of the side clutch shaft 155, and the differential mechanism 161 changes the mutual rotational speed to the left and right differential output shaft 162 for output. The differential mechanism 161 is provided with a case 163 rotatably in the mission case 145, and the front ends of the left and right differential output shafts 162 are exposed in the case 163. The left / right differential output shaft 162 of the embodiment is formed in a cylindrical shape, and the left / right differential output shaft 162 is fitted to a mounting shaft 164 provided on the mission case 145 so as to rotate independently. A left and right bevel gear 165 is provided at the front end of the left and right differential output shaft 162 so as to be opposed to each other. In the embodiment, the left and right bevel gears 165 are also integrally provided at the tip of the left and right differential output shaft 162 and are loosely fitted to the mounting shaft 164.

  The left and right bevel gears 165 mesh with intermediate bevel gears 167 rotatably attached to a shaft 166 fixed to the case 163, respectively, and a case rotation passive gear 167 is provided on the outer periphery of the case 163. The turning transmission gears 168 provided on the respective gears mesh with the axle gears 160, respectively.

  The differential mechanism 161 changes the rotation of the case 163 via the case rotation passive gear 167, and changes the rotation of the turning transmission gear 168 provided in each of the left and right differential output shafts 162, thereby changing the axle inside the turning. A slow turn that is driven and rotated slower than the axle on the outside of the turn, a brake turn that is made by stopping the axle on the inside of the turn, and a spin turn that is made by driving the axle on the inside of the turn opposite to the axle on the outside of the turn I do.

  Thus, in the vicinity of the differential mechanism 161, a turning transmission device 169 for transmitting rotation to the case rotation passive gear 167 is provided. Reference numeral 170 denotes a case rotation gear that constitutes a part of the turning transmission device 169 that always meshes with the case rotation passive gear 167, and is provided on the turning intermediate shaft 171. An inner boss 172 is fitted to the turning intermediate shaft 171 so as to be freely rotatable, and a linear input gear 173 is provided on the inner boss 172 so as to rotate integrally. The rectilinear input gear 173 is always meshed with a passive gear 156 that is meshed with the center gear 154 at all times.

  A casing 174 is provided on the outer periphery of the turning intermediate shaft 171 so as to rotate integrally therewith, and a disk is provided on the inner periphery of the casing 174. The disk can be connected to and disconnected from the disk provided on the outer periphery of the inner boss 172. A straight-travel clutch 175 is configured so as to abut against.

  When the rectilinear clutch 175 is engaged, the rotation of the center gear 154 is transmitted from the rectilinear input gear 173 to the casing 174 via the inner boss 172, and the casing 174 rotates the turning intermediate shaft 171 to rotate the case rotating gear 170. Rotate.

  The differential mechanism 161 has the left and right differential output shafts 162 and 21 so that when the linear clutch 175 is engaged, the rotation transmitted from the differential mechanism 161 is the same as the rotation transmitted from the left and right side clutch 158 and is not mechanically locked. The case 163 is rotated so as to have the same number of revolutions, and the case 163 is actuated for straight travel, and the rotation of the same rotating left and right bevel gears 165 is transmitted to the left and right axles 159 via the turning transmission gear 168 and travels straight. .

  A drum 176 is provided on the outer periphery of the casing 174, a piston 177 is provided on the base side of the drum 176, and an outer cylinder chamber 178 is formed between the piston 177 and the transmission case 145.

  The drum 176 is provided with an inner plate 179. When oil is fed from the oil feed port 180 to the outer cylinder chamber 178, the piston 177, the drum 176, and the inner plate 179 move in the direction of the arrow in FIG. The straight clutch 175 is disengaged from the disk on the outer periphery of the inner boss 172.

  An outer plate 45 is provided on the case rotating gear 170 side of the inner plate 179, and a spring 182 is provided between the inner plate 179 and the outer plate 181 to urge the linear clutch 175 in the entering direction. 175 is always on.

  An outer boss 184 is rotatably provided on the outer periphery of the inner boss 172, and a disk provided on the inner periphery of the casing 174 is in contact with a disk provided on the outer periphery of the outer boss 184 so as to be freely removable. A clutch 186 is configured. The outer boss 184 is provided with a turning input gear 187, and the turning input gear 187 meshes with the turning intermediate gear 187a.

  The turning input gear 187 and the turning intermediate gear 187a are set to a gear ratio capable of transmitting a rotation having a predetermined turning radius with respect to the rotation transmitted from the side clutch 158 to the axle 159 (the turning clutch 186 is completely set). The differential mechanism 161 is set to be capable of outputting for spin turn when in the entering state).

  When the clutch 186 for turning is supplied to the outer cylinder chamber 178 and the clutch 175 for straight running is turned off, the turning intermediate gear 187a → the turning input gear 187 → the outer boss 184 → the disk → the casing 174 → This is transmitted to the case rotating gear 170 via the turning intermediate shaft 171 to operate the differential mechanism 161 for turning.

  That is, when either one of the rectilinear clutch 175 and the turning clutch 186 is disengaged, the casing 174 is juxtaposed in the moving direction of the respective discs so that either one is engaged, and the discs of the rectilinear clutch 175 are arranged. The outer cylinder chamber 178 is provided on the moving direction cut side, the spring 182 is provided on the disk moving direction entry side of the linear clutch 175, and when oil is supplied to the outer cylinder chamber 178, the piston 177 moves the drum 176 and the inner plate 179. Then, the disc of the casing 174 is detached from the disc on the outer periphery of the inner boss 172, the straight-traveling clutch 175 is disengaged, and the outer plate 181 is moved by the movement of the casing 174, and the turning clutch 186 is engaged.

  In this case, the turning clutch 186 changes the contact pressure of the disk and continuously transmits the rotation transmission “0” from the cut-off state (the straight-travel clutch 175 is engaged and the contact pressure is “0”) to the engaged state. Thus, the rotation of the case 163 of the differential mechanism 161 is changed so as to be able to perform a slow turn, a brake turn, and a spin turn as described above.

  Therefore, the turning transmission device 169 transmits the rotation transmission for activating the differential mechanism 161 for straight travel, and the turning clutch 186 for transferring the transmission of rotation for operating the differential mechanism 161 for turning. A straight traveling clutch 175 to be connected / disconnected is provided.

  In the embodiment, the brake turn is performed by stopping the rotation of the axle 159 on the inner side of the turn by the differential mechanism 161, and the vehicle body is braked by a main transmission lever that changes the traveling speed described later. A separate parking brake pedal may be provided.

FIG. 4 shows a combine hydraulic circuit.
Oil that is sucked up by the hydraulic pump 12 from the oil tank 13 and discharged at high pressure is distributed to the clutch system oil path 14, the operation system oil path 15, and the pressure adjusting oil path 16.

The pressure adjusting oil passage 16 is connected to the drain oil passage 38 through which the high pressure relief valve 69 returns the oil to the oil tank 13, and holds the oil pressure in the clutch oil passage 14 and the operation oil passage 15 at a constant high pressure.
The clutch oil passage 14 is depressurized by the low pressure relief valve 57, supplied to the electromagnetic switching valve 58 through the fixed throttle 63 and the filter 64, and used for the operation of the main clutch 61.

  The operation system oil passage 15 passes through the filter 65 and flows to the side clutch system oil passage 66 alone or to both the side clutch system oil passage 66 and the work system oil passage 67 by the flow path switching valve 17. The oil flowing in the side clutch system oil passage 66 is sent to the left and right side clutch operation valves 20 and 21 through the throttle 18 and the filter 68 and used for the operation of the left and right side clutch cylinders 59 and 60. A manual relief valve 77 is provided in a return oil passage 78 connected to the extending side of the left and right side clutch cylinders 59, 60. The surplus oil in the id clutch oil passage 66 is sent to the work oil passage 67 through the check valve 19.

The pressure of the working system oil passage 67 is adjusted by the pressure regulating valve 32 through the two throttles 30, 31 and the relief valve 29, and sent to the main working oil passage 39.
The oil in the main working oil passage 39 is sent from the cutting oil passage 70 to the cutting electromagnetic control valve 36 for raising and lowering the cutting device 1. From the cutting electromagnetic control valve 36, the return is connected to the drain oil passage 38 via the pilot check valve 33 and the fixed throttle 34 to the cutting passage lift cylinder 37 through the oil passage to be sent to the cutting lift cylinder 37 and the lowering speed adjusting variable throttle valve 35 for changing the throttle amount. The oil passage is connected. The fixed throttle 34 may be a fixed throttle valve with a check valve.

  The variable throttle valve 35 for adjusting the lowering speed is an electromagnetic throttle adjusting valve. When the cutting operation is performed in the off state or during cutting, the throttle is opened to the maximum, and the lifting / lowering switching speed of the cutting electromagnetic control valve 36 is controlled to control the cutting device 1. The descent speed can be changed quickly. In addition, the reaping device lifting lever provided in front of the driver's seat and the opening of the variable throttle valve 35 for adjusting the lowering speed are interlocked, and the output of the electromagnetic proportional solenoid is changed and lowered as the turning angle of the reaping device lifting lever is increased. The opening of the throttle of the variable throttle valve 35 for speed adjustment can be increased to increase the flow of oil, and the lowering speed of the cutting device 1 can be increased.

  The electromagnetic throttle adjusting valve 35 does not increase the throttle from zero, but changes the minimum throttle to the maximum throttle, and the cutting device 1 is slightly lowered only by switching to the lowering of the cutting electromagnetic control valve 36. By doing so, it is possible to perform an operation of gradually lowering the reaping device 1 by an on / off operation of slightly tilting or returning the reaping device lifting lever.

Further, during the cutting operation, the cutting device 1 is not moved up and down greatly, so the electromagnetic throttle adjustment valve 35 may be fixed and used with the minimum throttle.
Further, the control of the electromagnetic throttle adjusting valve 35 does not change the throttle by changing the rotation angle of the reaping device lifting lever, but increases the aperture opening speed as the rotational speed of the reaping device lifting lever increases. You may control as follows.

  Furthermore, a sensor for detecting that the cutting device 1 has approached the ground is provided, and the aperture is reduced when the sensor detects the vicinity of the ground while the aperture of the electromagnetic throttle adjustment valve 35 is opened wide and rapidly lowered. The lowering speed of the reaping device 1 can be moderated to easily adjust the height of the reaping device and prevent the reaping device 1 from colliding with the ground.

  Specifically, the electromagnetic throttle adjusting valve 35 changes the throttle within a range of 0.7 to 1.7 mm. If the lowering speed of the reaping device 1 cannot be increased at the maximum of the throttle range, the fixed throttle 34 is used. The maximum descending speed of the device 1 can be increased by exchanging for a larger one.

FIG. 6 shows a specific configuration of the control valve. The cutting electromagnetic control valve 36 and the pilot check valve 33 are integrally assembled with the speed adjustment valve 35 interposed therebetween.
The lowering speed adjusting variable throttle valve 35 may be a two-position switching type three-way switching valve, and the return-side oil passage may be switched between high and low with or without throttling of the return oil passage.

  Further, the lowering speed adjusting variable throttle valve 35 may be constituted by an electromagnetic proportional reduction valve, and the descending speed of the reaping device 1 may be changed by changing the flow rate in two steps or steplessly. The electromagnetic proportional reduction valve controls so that the degree of opening of the throttle is increased when the value of the current supplied to the electromagnetic proportional solenoid is increased.

  The auger oil passage 71 branched from the main working oil passage 39 is sent to the auger control valve 42 for raising and lowering the grain discharge auger 8. An auger control valve 42 is connected to an oil passage that is fed to the auger lifting cylinder 43 through the check valve 40 and the throttle 41 and a return oil passage that is connected to the drain oil passage 38. In addition, if the lowering speed adjusting variable throttle valve 35 is provided in the return oil passage so that the descending speed of the grain discharge auger 8 can be changed, the storage speed of the grain discharge auger 8 in the receptacle can be adjusted. Operation becomes easier. At that time, as the grain discharge auger 8 approaches the receptacle, the descending speed is slowed to eliminate the storage shock.

  The left rolling oil passage 72 branched from the main working oil passage 39 is sent to the left rolling control valve 46 for left rolling of the chassis 2. From the left rolling control valve 46, an oil passage to be sent to the left rolling cylinder 47 through the check valve 44, the throttle 45 and the check valve 53, an oil passage to be sent to the contraction side of the left rolling cylinder 47, and a return oil passage connected to the drain oil passage 38. Is connected.

  The right rolling oil passage 73 branched from the main working oil passage 39 is sent to the right rolling control valve 50 for the right rolling of the chassis 2. From the right rolling control valve 51, an oil passage to be sent to the right rolling cylinder 51 through the check valve 48, the throttle 49 and the check valve 54, an oil passage to be sent to the contraction side of the right rolling cylinder 51, and a return oil passage connected to the drain oil passage 38. Is connected.

  If the variable throttle valve 35 for adjusting the lowering speed is provided in the return oil passage of the left rolling cylinder 47 and the right rolling cylinder 51 so that the horizontal lowering speed of the chassis 2 can be changed, the horizontal control of the chassis 2 can be performed. The sensitivity can be changed.

  The pitching oil passage 74 at the end of the main working oil passage 39 is sent to the pitching control valve 55 for rolling the chassis 2. From the pitching control valve 55, an oil passage that is sent to the expansion side of the pitching cylinder 56 through the check valve 52, an oil passage that is sent to the contraction side of the pitching cylinder 56, and a return oil passage that is connected to the drain oil passage 38 are connected.

  In addition, if the variable throttle valve 35 for adjusting the lowering speed is provided in the return oil passage of the pitching cylinder 56 so that the front / rear tilt speed of the chassis 2 can be changed, the sensitivity of the front / rear horizontal control of the chassis 2 can be changed. Become.

A suction oil passage 76 of the HST drive hydraulic circuit is connected between the hydraulic pump 12 and the filter 75.
7 to 10 show examples of the specific structure of the manual relief valve 77. The manual relief valve 77 is provided with a poppet 83 that opens a flow path to the discharge port 82 with oil pressure from the supply port 81 in the main body 80, and an adjustment screw 87 that is screwed to the opposite side of the supply port 81 of the main body 80. The inflow pressure is adjusted by pushing the poppet 83 with a compression spring 84 fitted to the tip of a slidable push pin 86.

  In the structure of FIG. 7, the push pin 86 is fitted and supported on the tip of the adjustment screw 87 by the bush 90 and O-rings 98 and 99, and a stopper 91 is attached to the push pin 86 side by the ring 100. A compression spring 92 is interposed between the end portion and the stopper 91. The interval A between the end surface 87p of the adjustment screw 87 and the end surface 91p of the stopper 91 is narrower than the interval B between the poppet 83 and the push pin 86 inside the main body 80 until the end surface 91p of the stopper 91 hits the end surface 87p of the adjustment screw 87. Even if the push pin 86 is pushed in, the tip of the push pin 86 does not hit the poppet 83, and the poppet 83 and its surroundings are not damaged.

The position of the tip of the push pin 86 on the poppet 83 side is adjusted by the degree of screwing of the adjustment screw 87 into the main body 80, and the adjustment screw 87 is fixed with the fixing screw 88.
The structure of FIG. 8 differs from that of FIG. 7 in that the end structure of the adjustment screw 87 and the O-ring 99 are integrated with the dust seal 93, and the structure of the stopper 91 is the stopper 91 screwed into the push pin 86. Is fixed with a fixing screw 95. This structure is characterized in that the distance A between the end face 87p of the adjusting screw 87 and the end face 91p of the stopper 91 can be adjusted by adjusting the screwing position of the stopper 91 with respect to the push pin 86.

  The structure of FIG. 9 is different from FIG. 8 in that the integrally mounted dust seal 93 is a dust seal 94 with a metal ring, and when a presser 96 that holds the metal seal is mounted, the end surface 96p of the presser 96 and the end surface 91p of the stopper 91 are The allowable stroke of the push pin 86 is determined by the interval A.

  The structure of FIG. 10 differs from FIG. 9 in that when the presser 96 is a washer 97 embedded in the adjustment screw 87, the allowable stroke of the push pin 86 is determined by the distance A between the end face 97p of the washer 97 and the end face 91p of the stopper 91. .

  A hydraulic circuit of the combiner that splits the oil sent from the hydraulic pump into a working oil passage that moves the mowing device or grain discharge auger up and down with a proportional flow control valve and a vehicle body control oil passage that rolls and pitches the vehicle body Although there is a configuration, if the raising operation of the harvesting device or the grain discharge auger and the lowering operation of the vehicle body are performed simultaneously with this circuit configuration, there is a problem that the harvesting device is lowered and then raised, but this is a vehicle control oil. Because the pressure drop in the road becomes the pressure drop in the working oil path, a pressure-holding check valve is installed on the supply side of the vehicle body control oil path that uses a spring to set the passing pressure to a predetermined pressure or higher. Or a relief valve with a fixed throttle, or a counter balance valve that maintains a predetermined oil pressure in the return oil path of each of the left and right rolling cylinders and the pitching cylinder. In the configuration in which the counter balance valve is provided, if the counter balance valve is provided on the inlet side plug of the check valve, the manufacturing cost is reduced.

  FIG. 11 shows a specific embodiment of the relief valve, which is formed on the adjusting screw 102 by pressing the spring seat 104 holding the bowl 106 in the main body 101 to the inlet plug 107 with a spring 108 interposed between the adjusting screw 102. A pin portion 103 to be inserted is inserted into a hole portion 105 formed in the spring seat 104 to provide a damper function. With this structure, there are fewer parts than in the past and processing becomes easier.

  FIG. 12 is also a specific embodiment of the relief valve. The difference from FIG. 11 is that a pin portion 109 is formed in the spring seat 104 and this pin portion 109 is inserted into a hole portion 110 formed in the adjusting screw 102 to function as a damper. Is about to have

  In the embodiment of the relief valve of FIG. 13, the ball 111 is interposed between the receiving hole 112a of the spring retainer 112 that holds the spring 108 and the receiving hole 102a of the adjusting screw 102. The place where the pin portion 109 of the spring seat 104 is inserted into the hole portion 113 is the same as in the prior art.

  FIG. 14 shows a specific example of the pilot check valve. The check valve 115 and the plug 116 are attached to the main body 114 with a pilot spool 118 provided in the main body 114 interposed therebetween. As a positioning when the pilot spool 118 is assembled into the main body, a hole 118a is provided at the end of the pilot spool 118, and a pin 116a formed at the tip of the plug 116 is fitted into the hole 118.

  In the specific example of the pilot check valve of FIG. 15, the pilot spool 118 is attached to the tip of the sleeve 121 of the check valve 115 with a C-type retaining ring 120, and the plug 116 of FIG. In this configuration, since the pilot spool 118 is integrated with the check valve 115, assembly is facilitated.

FIG. 16 is a control block diagram according to automatic control of the traveling device.
First, as a data signal to be input to the controller 125, a power steering position sensor 126 inputs a left / right tilt signal of a power steering lever that performs a turning operation, and rotation signals of the left / right crawler drive shafts are a rotation sensor (left) 127 and a rotation sensor (right). The pressure signals of the left and right cylinders that are input from 128 and operate the left and right side clutches are input from the cylinder pressure sensor (left) 129 and the cylinder pressure sensor (right) 130, and the voltage of the power steering solenoid that operates the side clutch is the power steering solenoid. Input is from a voltage change sensor (left) 131 and a power steering solenoid voltage change sensor (right) 132.

  The control signal output from the controller 125 is output to the swing brake pressure adjusting proportional valve 133, and the operation signal is output to the power steering solenoid (left) 134 and the power steering solenoid (right) 135 that turn the left and right side clutches on and off. Then, a flashing signal is output to the monitor lamp 136 that displays the running stability, a flashing signal is output to the blinker 137 that displays the turning direction, and a flashing signal is output to the ACD lamp 138 that displays the automatic direction control state. A ringing signal is output to the back buzzer 139 that rings at the time of reverse travel, a stop signal is output to the engine stop solenoid 140 that stops the engine rotation, and a neutral signal is output to the HST neutral return motor 141 that neutralizes the trunnion shaft of the continuously variable transmission. Is output and HST input to turn on and off the tension clutch to the continuously variable transmission Nyusetsu signal is output to the Pensions Nyusetsu motor 143.

  The turning structure of the traveling device of the present embodiment is a combination of a side clutch and a differential mechanism. Since the differential mechanism is operated after the side clutch is disconnected, the side clutch is not completely disconnected. Double engagement will damage the transmission mechanism. The following control is for preventing the above-described double meshing.

  The first control is to monitor the voltage changes of the power steering solenoid voltage change detection sensor (left) 131 and the power steering solenoid voltage change detection sensor (right) 132, and if there is no voltage change even if the power steering lever is turned, the side clutch The proportional brake valve 133 for adjusting the turning brake pressure is not increased, or the HST neutral return motor 141 is operated to neutralize the continuously variable transmission and cut off the power transmission to the side clutch. The stop solenoid 140 is operated to stop the engine, the back buzzer 139 is sounded, the blinker 137, the monitor lamp 136 and the ACD lamp 138 are flashed, and the HST input tension on / off motor 143 is disengaged. Perform emergency control.

  Also, the output difference between the rotation sensor (left) 127 and the rotation sensor (right) 128 is monitored, and if there is no output difference even if the power steering lever is turned, the side clutch is not disengaged. I do.

  Furthermore, if the pressure signal monitors the outputs of the cylinder pressure sensor (left) 129 and the cylinder pressure sensor (right) 130 and there is no pressure increase even if the power steering lever is turned, the side clutch is not disengaged. Emergency control similar to the above is performed.

  As the circuit configuration, if the oil that has passed through the hydraulic cylinder that operates the left and right side clutches is allowed to flow to the proportional valve 133 for adjusting the swing brake pressure, the differential mechanism will not operate unless the hydraulic cylinder is operated. It will never be.

It is a whole side view of the combine of a present Example. It is sectional drawing of a mission case. It is a partially expanded sectional view of a mission case. It is a hydraulic circuit diagram of a combine. It is a partially expanded view of a hydraulic circuit. It is a sectional side view of a hydraulic block. It is a sectional side view of a manual relief valve. It is a sectional side view of the manual relief valve of another Example. It is a sectional side view of a relief valve. It is a sectional side view of the relief valve of another Example. It is a sectional side view of a pilot check valve. It is a sectional side view of the relief valve of another Example. It is a sectional side view of the relief valve of another Example. It is a sectional side view of the pilot check valve of another example. It is a sectional side view of the pilot check valve of another example. It is a control block diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mowing device 12 Hydraulic pump 35 Electromagnetic variable throttle valve 36 Mowing electromagnetic switching valve 37 Mowing lifting cylinder 70 Mowing oil passage

Claims (2)

A cutting electromagnetic switching valve (36) is provided in a cutting oil passage (70) for supplying oil from a hydraulic pump (12) to a cutting lifting cylinder (37) that moves up and down the cutting device (1), and the cutting electromagnetic switching valve (36 ) Is provided with an electromagnetic variable throttle valve (35) for adjusting the lowering speed of the mowing device (1), and this electromagnetic variable throttle valve (35) is kept in a fully opened state when the mowing electromagnetic switching valve (36) is turned off. Combine harvester lifting / lowering hydraulic control device characterized in that it is configured to control as much as possible. A cutting electromagnetic switching valve (36) is provided in a cutting oil passage (70) for supplying oil from a hydraulic pump (12) to a cutting lifting cylinder (37) that moves up and down the cutting device (1), and the cutting electromagnetic switching valve (36 ) Is provided with an electromagnetic variable throttle valve (35) for adjusting the lowering speed of the reaping device (1), and the electromagnetic variable throttle valve (35) is controlled so as to be kept in the maximum open state when the reaping operation starts. Combine harvester lifting / lowering hydraulic control device characterized by that.

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