JP2017009082A - Hydraulic operation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely implement an operation by securing an oil feed amount to an external hydraulic work machine by limiting a turning speed in an operation of a work operation lever.SOLUTION: A cam 57 is disposed on a base portion of a work operation lever 7 tilted in operation, a tip of a bush rod 59 connected to one end of a spool 58 of a pilot valve as a control valve of a left remote controller valve 52, is kept into contact with the cam 57, and rotation limitation means 90 for limiting rotation of the work operation lever 7 from a set angle, is detachably disposed near the push rod 59.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an operation device for a remote control valve. When operating two operating actuators simultaneously by operating an operating lever, the oil supply to one hydraulic actuator is limited, and the operation of the other hydraulic actuator is restricted. The present invention relates to a technique of an operation device that can be operated without stopping.

Conventionally, in the hydraulic circuit of the excavation turning work machine for supplying pressure oil to the hydraulic actuators for driving the boom, arm, and bucket, and for turning the main body by the first, second, and third hydraulic pumps, When each hydraulic actuator is driven independently, the first and third hydraulic pumps are used for boom driving, the second and third hydraulic pumps are used for arm driving, and the first hydraulic pump is used for bucket driving. A technique of supplying pressure oil to each hydraulic actuator by a third hydraulic pump when the main body turns is known (see, for example, Patent Document 1).
A technique is also known in which an operation feeling corresponding to the load of an actuator is obtained when an operator operates an operation lever (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-88627 JP 2001-214905 A

  In the technique of Patent Document 1, when an external hydraulic working machine is attached and operated, pressure oil is supplied from a second hydraulic pump and a third hydraulic pump to a PTO port for external extraction provided in advance. It was. In this case, for example, when a work is performed with a mower having a large hydraulic oil flow rate at the time of working as an external hydraulic working machine, if the turning operation is performed while the mowing work is performed, the first of the two hydraulic pumps The whole amount of pressure oil from the three hydraulic pumps will be spent on turning. If the turning load and the PTO load are high at this time, the flow rate of the second hydraulic pump is extremely reduced by the torque control of the variable pump, and the amount of oil supplied to the external hydraulic work machine (PTO) is also reduced. The number will decrease. In other words, if the turning operation is performed during mowing work, the rotation speed of the external hydraulic working machine decreases, and grass tends to get entangled with the rotating shaft. Had to stop.

  Also, by reducing the turning speed by operating the operation lever, the amount of oil supplied to the turning motor is appropriately suppressed, and the remaining oil is supplied to the external hydraulic work machine side to be merged. It is also possible to maintain the rotational speed of the external hydraulic work machine by setting the operating position of the operating lever so that it can be secured, but the operation depends on the operator's sense (skill), so it is difficult unless you are an expert It was.

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
That is, in claim 1, a cam is provided at the base of the operation lever to be tilted, and the tip of the push rod connected to one end of the spool of the control valve is brought into contact with the cam, and is located in the vicinity of the push rod. A rotation restriction imparting means for restricting the rotation of the operation lever from a set angle is detachably provided.

According to a second aspect of the present invention, the restriction start position by the rotation restriction imparting means is a position where the flow can be diverted to a flow rate for operating the external hydraulic working machine while operating the turning motor.
According to a third aspect of the present invention, the rotation restriction imparting means is arranged on the outer periphery of the push rod and is made of an elastic body.
According to a fourth aspect of the present invention, the rotation limit applying means is constituted by a coil spring.

As effects of the present invention, the following effects can be obtained.
When turning while operating an external hydraulic work machine, when the turning operation lever is operated, the rotation is restricted by the rotation restriction applying means at the optimum flow rate position of the hydraulic oil required for turning, and the operation is easily performed at that position. The position can be maintained and work can be performed without stopping the external hydraulic working machine.

The side view which showed the whole structure of the hydraulic working vehicle provided with the hydraulic operation apparatus of this invention. The hydraulic circuit diagram of a hydraulic work vehicle. Sectional drawing of an operation lever provided with the rotation restriction provision means of 1st embodiment. The expanded sectional view of a remote control valve. Sectional drawing of an operation lever provided with the rotation restriction provision means of 2nd embodiment. Sectional drawing of an operation lever provided with the rotation restriction provision means of 3rd embodiment. Sectional drawing of an operation lever provided with the rotation restriction provision means of 4th embodiment.

{Common embodiment}
Below, the whole structure of the backhoe 1 which is an Example of the hydraulic working vehicle which comprises the hydraulic device based on this invention is demonstrated using FIG. 1 and FIG. In FIG. 1, the direction of arrow F is the front.

  As shown in FIG. 1, the backhoe 1 mainly includes a crawler type traveling device 2, a turning frame 3, a working unit 5, and the like.

  The crawler type traveling device 2 is a member constituting the lower structure of the backhoe 1, and a pair of left and right crawlers 11 and 11 are wound between a driving wheel and a driven wheel, respectively, to support the driving wheel and the driven wheel. A blade 12 and a blade cylinder 13 which is a hydraulic cylinder for rotating the blade 12 in the vertical direction are provided from the left and right center of the frame to the rear. The drive wheels are driven by traveling hydraulic motors 63 and 64 attached to the track frame.

  The revolving frame 3 is a member constituting the upper structure of the backhoe 1, and is attached to the upper portion of the crawler type traveling device 2 via a revolving bearing from the front, rear, left, and right center of the track frame. A swing hydraulic motor 62 is mounted on the swing frame 3, and the swing drive gear fixed on the output shaft of the swing hydraulic motor 62 is engaged with a ring gear fixed to the track frame to operate the swing hydraulic motor 62. By doing so, the turning frame 3 can be turned left and right.

  An engine 15 as a drive source and a first pump P1, a second pump P2, and a third pump P3 driven by the engine 15 are disposed on the rear portion of the turning frame 3. The upper part of the swivel frame 3 is a control unit, a seat 6 is disposed above the engine 15, work control levers 7 and 8 are disposed on the left and right of the seat 6, and travel levers 9L and 9R are disposed on the front. The upper part of the control unit is covered with a canopy 10. A boom bracket 19 for attaching the working unit 5 to the front left and right center of the revolving frame 3 is disposed.

  The working unit 5 mainly includes an arm 17, a boom 18, a boom bracket 19, an external hydraulic working machine 16 as a PTO hydraulic actuator, a bucket cylinder 20, an arm cylinder 21, a boom cylinder 22, a swing cylinder 25, and the like. Provided at the front of the revolving frame 3.

  The external hydraulic working machine 16 is attached instead of the normally attached bucket, and in this embodiment, a mower is attached. As the external hydraulic working machine 16, a rock drill, a gripper, or the like can be attached. The mowing machine as the external hydraulic working machine 16 is driven to rotate by the operation of the PTO hydraulic motor 65.

The arm 17 has an external hydraulic working machine 16 attached to its tip, and a base is pivotally attached to the tip of the boom 18 so as to be pivotable up and down.
The boom 18 has a shape that is bent forward in the middle of the machine body, and a base portion of the boom 18 is pivotally attached to the boom bracket 19 so as to be able to rotate back and forth.
The boom bracket 19 is a member that forms the base of the working unit 5, and a rear end portion of the boom bracket 19 is pivotally attached to the front end portion of the revolving frame 3 so as to be able to turn left and right.

The bucket cylinder 20 is a hydraulic cylinder for rotating the external hydraulic working machine 16 back and forth with respect to the arm 17.
A cylinder end of the bucket cylinder 20 is pivotally attached to a bracket 17 a provided at the base of the arm 17. The rod end of the bucket cylinder 20 is pivotally attached to the external hydraulic working machine 16 via a link. In this way, the mowing angle of the mower can be adjusted to the ground.

The arm cylinder 21 is a hydraulic cylinder for rotating the arm 17 with respect to the boom 18.
The cylinder end of the arm cylinder 21 is pivotally attached to a bracket 18 a provided on the upper surface of the middle part of the boom 18. The rod end of the arm cylinder 21 is pivotally attached to the bracket 17a.

The boom cylinder 22 is a hydraulic cylinder for rotating the boom 18.
The cylinder end of the boom cylinder 22 is pivotally attached to the front end of the boom bracket 19 so as to be rotatable. Further, the rod end portion of the boom cylinder 22 is pivotally attached to a bracket 18b provided on the front surface in the middle of the boom 18.
The swing cylinder 25 is a hydraulic cylinder for rotating the boom 18 left and right with respect to the revolving frame 3. The swing cylinder 25 is interposed between the boom bracket 19 and the turning frame 3.

Next, the configuration of the hydraulic circuit 100 will be described with reference to FIG.
The hydraulic circuit 100 is driven by pressure oil discharged from the first pump P1, the second pump P2, and the third pump P3 driven by the engine 15 being sent to each hydraulic actuator via each control valve. The

  From the first pump P1 to the left traveling hydraulic motor 63 via the left traveling control valve 31 from the discharge oil passage 26, to the boom cylinder 22 via the boom control valve 32, and to the bucket cylinder 20 via the bucket control valve 33. A hydraulic circuit is formed so that oil can be fed. A load check valve 42 is provided in the supply oil passage to the bridge passage of the boom control valve 32, and a load check valve 43 is provided in the supply oil passage to the bridge passage of the bucket control valve 33.

  From the second pump P2, from the discharge oil passage 27 to the right traveling hydraulic motor 64 via the right traveling control valve 34, to the swing cylinder 25 via the swing control valve 35, and to the PTO hydraulic motor 65 via the PTO control valve 36. In addition, a hydraulic circuit is formed so that oil can be supplied to the arm cylinder 21 via the arm control valve 37. A load check valve 45 is provided in the supply oil passage to the bridge passage of the swing control valve 35, a load check valve 46 is provided in the supply oil passage to the bridge passage of the PTO control valve 36, and the bridge of the arm control valve 37 is provided. A load check valve 47 is provided in the supply oil passage to the passage.

  From the third pump P3, a hydraulic circuit is formed so that oil can be fed from the discharge oil passage 28 to the swing hydraulic motor 62 via the swing control valve 38 and to the blade cylinder 13 via the blade control valve 39. A load check valve 48 is provided in the supply oil passage to the bridge passage of the turning control valve 38, and a load check valve 49 is provided in the supply oil passage to the bridge passage of the blade control valve 39.

The left travel control valve 31 is switched by the rotation of the travel lever 9L, and the left travel hydraulic motor 63 can be rotated forward or backward. The right traveling control valve 34 is switched by the rotation of the traveling lever 9R, and the right traveling hydraulic motor 64 can be rotated forward or backward. Thus, the backhoe 1 can be moved forward, backward, and left / right.
When the operation control lever 8 of the control unit is rotated back and forth, the right remote control valve 51 is switched, the pilot hydraulic pressure is sent to the control unit of the boom control valve 32 and switched, and the boom cylinder 22 is expanded and contracted. 18 can be rotated.
When the work control lever 8 of the control unit is rotated left and right, the right remote control valve 51 is switched, the pilot hydraulic pressure is switched to the control unit of the bucket control valve 33, and the bucket cylinder 20 is expanded and contracted to the outside. The hydraulic working machine (bucket) 16 is rotatable.
When the work control lever 7 of the control unit is rotated back and forth, the left remote control valve 52 is switched, the pilot hydraulic pressure is sent to the control unit of the arm control valve 37, and the arm cylinder 21 is expanded and contracted. The arm 17 can be rotated.
When the work operation lever 7 of the control unit is rotated left and right, the left remote control valve 52 is switched, the pilot hydraulic pressure is sent to the control unit of the swing control valve 38 and switched, and the swing hydraulic motor 62 is rotated. The turning frame 3 can be turned.

However, the boom control valve 32, the bucket control valve 33, the arm control valve 37, and the turning control valve 38 are electromagnetic valves, and are configured by switches instead of the right remote control valve 51 and the left remote control valve 52 so that they can be switched electrically. It is also possible to configure.
The swing control valve 35 and the blade control valve 39 can be switched by operating an operation pedal or an operation lever (not shown).

  In the discharge oil passage 28 of the third pump P3, a confluence hydraulic circuit 40 is provided for the bucket cylinder 20, the boom cylinder 22, the arm cylinder 21, and the PTO hydraulic motor 65, and the boom cylinder 22 is driven independently. Sometimes, the pressure oil from the first pump P1 and the pressure oil from the third pump P3 are merged, the merged pressure oil is supplied to the boom cylinder 22 or the bucket cylinder 20, the amount of pressure oil is increased, and the boom 1 to increase the speed of operation. Further, when the PTO hydraulic motor 65 or the arm cylinder 21 is driven alone, the pressure oil from the second pump P2 and the pressure oil from the third pump P3 are merged, and the merged pressure is applied to the PTO hydraulic motor 65 or the arm cylinder 21. Oil is supplied so that the operation of the external hydraulic working machine 16 or the operation of the arm 2 can be increased.

  However, if the external hydraulic working machine 16 is a mower that requires a large amount of working hydraulic oil and performs work while turning, for example, if the turning is performed at the same time as the mowing work, the amount of oil supplied to the PTO is reduced. The number of rotations of the hydraulic motor 65 decreases, and uncutting occurs or grass is entangled. When the blade gets entangled with the blade and the rotational load increases, the relief is sometimes activated and stopped. Therefore, the operation speed of the work operation lever 7 is limited to limit the turning speed so as to ensure the amount of oil fed to the external hydraulic working machine 16 so as to ensure the work.

That is, in order to limit the turning speed, a rotation restriction imparting means 90 is provided between the work operation lever 7 and the left remote control valve 52. However, the rotation restriction imparting means 90 is removed when it is not necessary for normal work (work with a bucket).
The left remote control valve 52 includes a pair of left and right pilot valves 55L and 55R for switching the pilot hydraulic pressure for controlling the swing control valve 38, and a pair of front and rear pilot valves (for switching the pilot hydraulic pressure for controlling the arm control valve 37). (Not shown). The right remote control valve 51 includes a pair of pilot valves (not shown) for switching the pilot hydraulic pressure for controlling the boom control valve 32, and a pair of left and right pilot valves (not shown) for switching the pilot hydraulic pressure for controlling the bucket control valve 33. ). The right remote control valve 51 and the left remote control valve 52 are configured in substantially the same manner, and the front, rear, left and right pilot valves are also configured in the same manner. Therefore, the turning pilot valves 55L and 55R will be described.

  As shown in FIGS. 3 and 4, the work operation lever 7 is attached to the upper part of the valve case 54 via a joint 56 so as to be able to rotate back and forth and right and left. A disc-shaped cam 57 is fixed to the lower end of the work operation lever 7, and the lower surface of the cam 57 is housed in the left remote control valve 52, and push rods 59 and 59 of a pair of left and right pilot valves 55L and 55R for turning. And an upper end of a push rod (not shown) of a pair of front and rear pilot valves for the arm.

  The push rods 59, 59 have upper ends protruding above the upper surface of the valve case 54, and lower ends are in contact with the upper surfaces of the spring seats 60, 60. The spring seats 60 and 60 are fitted to the upper ends of the spools 58 and 58, and the spools 58 and 58 are accommodated in a valve hole formed in the valve case 54 in the vertical direction. Each of the spools 58 is fitted with springs 91 and 92, and the springs 91 are interposed between the spring seat 60 and the valve case 54 to urge the spring seat 60 and the push rod 59 to slide upward. The spring 92 is interposed between the spring seat 60 and the spool 58 and urges the spool 58 to slide downward. The work operation lever 7 is held in a neutral position (front / rear / left / right center) by the biasing force of the springs 91 and 91.

  Then, a rotation restriction imparting means 90 is attached to the push rod 59 in one turning direction (left side in the present embodiment). In other words, the mowing machine is configured to cut in one direction (left direction) and not in the reverse direction. Therefore, the spool for left-turning operation is used to perform cutting work while turning leftward. On the push rod 59 linked to 58, a rotation restriction imparting means 90 is provided. However, if the mower is of a type that can work in both the left and right directions, the rotation limit imparting means 90 is also attached to the right push rod 59.

  In the first embodiment of the rotation restriction imparting means 90, as shown in FIG. 3, it is formed in a cylindrical shape, can be externally fitted to the push rod 59, and is detachably attached. The axial limit (vertical direction) length of the rotation restriction imparting means 90 is configured to be shorter than the length of the push rod 59 protruding from the upper surface of the valve case 54.

  In this way, when the work operation lever 7 is turned to the left, if the set angle is turned, the cam 57 comes into contact with the turning restriction imparting means 90 in the middle of turning and cannot turn any further, and the turning speed is further increased. Do not become. This contact position (set rotation angle), that is, a position (angle) at which the rotation of the work operation lever 7 is restricted is a position where the operating hydraulic pressure rises and relief is performed. Specifically, when the turning operation is performed during the mowing work by the external hydraulic working machine 16, the work by the external hydraulic working machine 16 can be maintained and the turning speed is limited. That is, this is a position where a sufficient amount of hydraulic oil can be obtained even when the external hydraulic working machine 16 is turned during work. In other words, even if the turning operation is performed, the rotational speed of the mowing machine does not fall below the set rotational speed at which grass entanglement occurs.

  This set rotational speed can be changed by creating and replacing the rotation restriction imparting means 90 having different axial lengths. That is, it is possible to turn while working at a predetermined number of revolutions by changing the rotation restriction imparting means 90 according to the type of the external hydraulic working machine 16 (the amount of hydraulic oil necessary for the work). As a structure of the rotation restriction imparting means 90, it is cylindrical and the work operation lever 7 is removed so that it can be attached to and detached from the outer periphery of the push rod 59. Or it comprises in the cross-sectional view substantially C-shaped cylinder shape, and is comprised from the push rod 59 side so that attachment or detachment is possible.

In addition, the material of the rotation restriction applying means 90 is made of hard metal or synthetic resin, so that the rotation range of the work operation lever 7 can be up to a set angle, and the rotation speed of the work can be reduced. It can be surely prevented.
Moreover, the material of the said rotation restriction provision means 90 can also be comprised with an elastic body. For example, as shown in FIG. 4, the rotation restriction imparting means 90 may be formed of a cylindrical rubber as an elastic body, or a coil spring as an elastic body as shown in FIG. it can. With such a configuration, when the work hydraulic lever 16 is turned, the work operation lever 7 is turned to turn, and when the set angle is reached, the lower surface of the cam 57 is turned to the rotation restriction applying means 90. The rotation resistance increases by abutting against the upper surface, and it is possible to recognize that the set angle has been reached with the sense of the hand. If it rotates beyond this rotational position, the hydraulic pressure increases and the possibility of relief increases. Further, when it is desired to further increase the turning speed at times other than during work, it is possible to increase the turning speed by deforming the elastic body by further applying force and turning.

  Further, the rotation limit applying means 90 may be configured to contact the work operation lever 7 instead of contacting the cam 57. That is, as a third embodiment of the rotation restriction applying means 90, as shown in FIG. 6, the rotation restriction applying means 90 is constituted by a leaf spring, and the lower end is fixed to the valve case 54 with a bolt or the like and moved upward. The upper end position of the rotation restriction applying means 90 is set as a position where the work operation lever 7 contacts when the set operation angle rotates. Thus, when the work operating lever 7 is turned, it can be easily recognized that it has come into contact with the turning restriction imparting means 90 in the middle and the turning resistance has increased and the set angle has been turned.

  Also, a detent mechanism 95 can be configured instead of providing the rotation limit applying means 90. That is, as a fourth embodiment of the rotation restriction imparting means 90, as shown in FIG. 7, a recessed portion (or a convex portion or a step is provided at a set rotational angle position on the contact surface of the cam 57 with the push rod 59. Part) 57a is formed, and when the work operation lever 7 is rotated to the set angle, the upper end of the push rod 59 is fitted into the recess 57a so as to be held lightly. Thus, as described above, it can be easily recognized that the set angle has been reached in the middle of the rotation operation of the work operation lever 7, and the work can be easily prevented from stopping. However, the arrangement position of the detent mechanism 95 is not limited to the cam 57 but can be provided at the joint 56.

  In the present embodiment, the rotation restriction imparting means 90 is provided on the remote control valve 52 for turning operation. However, according to the work mode, the remote control valve for boom operation, the remote control valve for arm operation, and the remote control for bucket operation. It can also be provided in the valve.

  As described above, the cam 57 is provided at the base portion of the work operation lever 7 to be tilted, and the push rod 59 connected to one end of the spool 58 of the pilot valve that becomes the control valve of the left remote control valve 52 is connected to the cam 57. Since the tip is abutted and a rotation restriction imparting means 90 for restricting the rotation of the work operation lever 7 from a set angle is detachably provided in the vicinity of the push rod 59, the external hydraulic working machine 16 and the turning are simultaneously operated. In this case, it is possible to prevent the operation of the external hydraulic working machine 16 from being stopped by restricting the operation angle of the work operation lever 7 that performs the turning operation by the rotation restriction imparting means 90. Further, the rotation restriction imparting means 90 can be removed when the external hydraulic working machine 16 is not used, and can be replaced in accordance with the external hydraulic working machine 16, so that the operation can be easily and inexpensively restricted.

  Further, the restriction start position by the rotation restriction applying means 90 is a position where the flow can be diverted to the flow rate for operating the external hydraulic working machine 16 while operating the turning motor 62, so that the turning can be performed while working by the external hydraulic working machine 16. Thus, the external hydraulic working machine 16 is not stopped and the work can be reliably performed without increasing the load.

  The rotation restriction applying means 90 is arranged on the outer periphery of the push rod 59 and is made of an elastic body. Therefore, when it is desired to further increase the turning speed, it can be realized by applying a force for deforming the elastic body to the work operation lever 7. The turning speed can be changed according to the working state of the external hydraulic working machine 16.

  Further, since the rotation restriction applying means 90 is constituted by a coil spring, the rotation restriction applying means 90 can be easily obtained at low cost and can be easily attached and detached. In addition, it is durable and can be stably controlled.

7 Work operation lever 16 External hydraulic working machine 36 PTO control valve 46 Load check valve 52 Left remote control valve 57 Cam 58 Spool 59 Push rod 62 Swing hydraulic motor 65 PTO hydraulic motor 90 Rotation restriction applying means

Claims (4)

  A cam is provided at the base of the operation lever to be tilted, and the tip of the push rod connected to one end of the spool of the control valve is brought into contact with the cam, and the rotation of the operation lever is set at a set angle in the vicinity of the push rod. The hydraulic operation device is characterized in that a rotation restriction imparting means for restricting from the above is detachably provided.   2. The hydraulic operating device according to claim 1, wherein the restriction start position by the rotation restriction applying unit is a position where the flow can be diverted to a flow rate for operating the external hydraulic working machine while operating the turning motor.   3. The hydraulic operating device according to claim 1, wherein the rotation restriction imparting unit is arranged on an outer periphery of the push rod and is formed of an elastic body.   The hydraulic operating device according to any one of claims 1 to 3, wherein the rotation restriction imparting means is constituted by a coil spring.

Images