WO2018051670A1

WO2018051670A1 - Pinching device for work machinery, and work machinery provided therewith

Info

Publication number: WO2018051670A1
Application number: PCT/JP2017/028336
Authority: WO
Inventors: 達也武下
Original assignee: コベルコ建機株式会社
Priority date: 2016-09-15
Filing date: 2017-08-04
Publication date: 2018-03-22
Also published as: JP2018044366A

Abstract

Provided is a device that makes it possible to accelerate a pinching operation with a high degree of freedom, without entailing significant pressure loss. A pinching device is provided with: a pinching device body (20) that includes a pair of pinching members and a switching drive actuator (28) and is set onto a distal end of a work arm; a main hydraulic pump (52) mounted onto a hull; a control valve (54); a bypass oil path (62) that bypasses the control valve (54) and communicates with one another a first and second port (30a, 30b) of the switching drive actuator (28); an oil path switching section (68) for opening and closing the bypass oil path (62); a check valve (66) provided to the bypass oil path (62); an auxiliary hydraulic pump (64) that supplies some of the hydraulic oil which is discharged from the first port (30a) in an opening operation of the pinching members to the second port (30b) via the bypass oil path (62); and an auxiliary hydraulic pump drive device (70) for driving the auxiliary hydraulic pump (64).

Description

Work machine pinching device and work machine equipped with the same

The present invention relates to a hydraulic pinch processing apparatus such as a crusher or a press machine, which is provided in a work machine having a work arm, and a work machine equipped with the apparatus.

Conventionally, for example, a hydraulic crusher is known as a pinching device provided in a work machine. The crusher includes a crusher main body attached to the attachment support portion, a pair of crushing arms rotatably connected to the crusher main body, a hydraulic drive device for driving the crushing arm hydraulically, Is provided. The hydraulic drive device opens and closes the crushing arms by rotating them in opposite directions, and crushes the processing object sandwiched between the crushing arms when operating in the closing direction.

The hydraulic drive device includes a hydraulic actuator interposed between the crushing arms and the crusher body. The higher the driving speed of the hydraulic actuator, the higher the working efficiency, but the driving speed is limited by the capacity and discharge pressure of the main hydraulic pump for supplying hydraulic oil to the hydraulic actuator. In order to obtain a higher driving speed with such a limited pump capacity and pump discharge pressure, it is necessary to add equipment for increasing the speed.

Patent Document 1 discloses a hydraulic drive device including a speed increaser for the speed increase. The speed increaser constructs a regeneration circuit that reduces a part of the return oil flowing out from the rod side chamber to the supply side by utilizing the area difference between the head side chamber and the rod side chamber of the hydraulic cylinder constituting the hydraulic actuator. Thus, it has a function of increasing the supply flow rate to the head side chamber.

The speed increaser disclosed in Patent Document 1 utilizes the difference in area between the head side chamber and the rod side chamber of the hydraulic cylinder, and is therefore used when the hydraulic cylinder is extended, generally when driven in the closing direction. Limited. Rather, the speed increase is required at the time of opening drive with a small load, and the speed increase at the time of opening driving cannot be performed. Further, the amount of hydraulic oil regenerated by the speed increaser is limited, and the degree of freedom in setting the speed increase rate is narrow.

Note that the operating speed of the sandwiching device increases the discharge flow rate of the main hydraulic pump, for example, selects a hydraulic pump having a larger capacity as the main hydraulic pump, or increases the number of main hydraulic pumps. However, a mere increase in the discharge flow rate of the main hydraulic pump is not preferable because it significantly increases the energy loss due to the pressure loss. In particular, the hydraulic actuator constituting the pinching device is provided at the tip of a long work arm in the work machine, while the main hydraulic pump for supplying hydraulic oil to the hydraulic actuator is mounted on the body of the work machine Therefore, the pipe length from the main hydraulic pump to the hydraulic actuator is large, and therefore the increase in pressure loss accompanying the increase in the discharge flow rate of the main hydraulic pump becomes very large.

Japanese Patent Laid-Open No. 10-169213

The present invention relates to a pinching processing device provided in a work machine having a work arm, which can increase the speed of pinching processing operation with a high degree of freedom without significantly increasing pressure loss, and the device. An object is to provide a working machine.

What is provided is a pinching device provided in a work machine including a machine body, a base end portion connected to the machine body, and a work arm having a distal end portion capable of relative displacement with respect to the base end portion. A pinch processing apparatus main body mounted on the distal end portion of the working arm, wherein the pinch processing member is movable in an opening / closing direction contacting and separating from each other, and the pair of pinching processing members are opened / closed. An opening / closing drive actuator coupled to the pair of sandwiching processing members to move in the direction, the opening / closing drive actuator having a first port and a second port, and supplying hydraulic oil through the first port. The hydraulic oil is discharged through the second port while moving the pair of sandwiching processing members in the closing direction by receiving, while the hydraulic oil is supplied through the second port. A main body of a pinch processing device, which is a hydraulic actuator that discharges hydraulic oil through the first port while moving a pair of pinching processing members in the opening direction, and hydraulic oil mounted on the machine body and supplied to the opening / closing drive actuator It is interposed between the main hydraulic pump that discharges, the opening / closing drive actuator and the main hydraulic pump, and supplies hydraulic oil discharged from the main hydraulic pump to the first port and is discharged from the second supply port. A closed drive position for forming an oil passage for guiding the hydraulic oil to the tank and the hydraulic oil discharged from the main hydraulic pump to the second port and the hydraulic oil discharged from the first supply port to the tank A control valve that can be switched to an open drive position that forms an oil passage, and the opening and closing drive rather than the control valve A bypass oil passage that bypasses the control valve at a position close to the actuator and communicates the first port and the second port of the opening / closing drive actuator with each other, and blocks the flow of the hydraulic oil in the bypass oil passage An oil passage opening and closing portion that can be switched between a shut-off state and an allowable state that allows the hydraulic oil to flow by opening the bypass oil passage, and an operation that is directed from the second port to the first port in the bypass oil passage. A check valve that prevents backflow of oil, an auxiliary hydraulic pump that operates to supply a part of the hydraulic oil discharged from the first port to the second port through the bypass oil passage, and the auxiliary hydraulic pump An auxiliary hydraulic pump driving device for driving the motor.

Also provided is a work machine comprising a machine body, a work arm having a base end connected to the machine body, a work arm having a tip that can be displaced relative to the base end, and the pinching device. Is done. In this work machine, the pinch processing device main body and the opening / closing drive actuator of the pinch processing device are attached to the tip of the work arm. The bypass oil passage, the opening / closing switching unit, and the auxiliary hydraulic pump are provided on the work arm.

It is a side view which shows the demolition machine which is an example of the working machine provided with the crushing apparatus which is the pinch processing apparatus which concerns on the 1st Embodiment of this invention. It is a front view which shows the crusher of the said crushing apparatus, Comprising: It is a figure which shows the state which has a pair of crushing arm of the said crusher in a closed position. It is a front view which shows the said crusher, Comprising: It is a figure which shows the state which has a pair of said crushing arm in an open position. It is a hydraulic circuit diagram which shows the main components of the said crushing apparatus. It is a block diagram which shows the function structure of the controller shown by FIG. It is a flowchart which shows the calculation control operation | movement of the said controller. It is a graph which shows the 1st example of the positive control command and motor current command which are output from the said controller according to opening operation pilot pressure. It is a graph which shows the 2nd example of the positive control command and motor current command which are output from the said controller according to opening operation pilot pressure. It is a hydraulic circuit diagram which shows the main components of the crushing apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the function structure of the controller shown by FIG. It is a flowchart which shows the calculation control operation | movement of the controller shown by FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments are examples embodying the present invention, and are not of a nature that limits the technical scope of the present invention.

FIG. 1 is a side view showing a dismantling machine that is a work machine according to a first embodiment of the present invention. The dismantling machine includes a lower traveling body 2 having a pair of left and right crawlers 2a, an upper revolving body 4 that is turnably mounted on the lower traveling body 2, and a work arm 10 that is attached to the upper revolving body 4. A crushing device which is a pinching processing device. The lower traveling body 2 and the upper swing body 4 constitute a body of the dismantling machine.

The working arm 10 has a proximal end portion and a distal end portion on the opposite side. The base end portion is connected to the upper swing body 4 so as to be rotatable in the undulation direction, and the tip end portion can be moved relative to the base end portion in the vertical direction and the front-rear direction. A crusher 20 that is a main body of the crushing apparatus is attached to the tip portion.

The working arm 10 has a main boom 12, an inter boom 14, and an arm 16 in detail. The main boom 12 has a base end portion that is connected to the upper swing body 4 so as to be rotatable in the undulation direction, and a tip end portion on the opposite side, and the base end portion is the entire work arm 10. It corresponds to the base end portion. The inter boom 14 has a base end portion that is rotatably connected to a tip end portion of the main boom 12 around a horizontal axis, and a tip end portion on the opposite side. The arm 16 has a base end portion that is connected to the inter boom 14 so as to be rotatable about a horizontal axis, and a distal end portion on the opposite side. The distal end portion of the arm 16 corresponds to the distal end portion of the entire working arm 10, and the crusher 20 is detachably connected to the distal end portion so as to be rotatable about a horizontal axis.

The working arm 10 further includes a plurality of hydraulic cylinders for moving the elements, that is, a main boom cylinder 15, an inter boom cylinder 17, and a crusher cylinder 19. The main boom cylinder 15 is interposed between the upper swing body 4 and the main boom 12 so that the main boom 12 is rotated in the undulation direction with respect to the upper swing body 4 by expansion and contraction. The inter boom cylinder 17 is interposed between the main boom 12 and the inter boom 14 so as to rotate the inter boom 14 with respect to the main boom 12 by expansion and contraction. The crusher cylinder 19 is interposed between the arm 16 and the crusher 20 so as to rotate the crusher 20 with respect to the arm 16 by expansion and contraction thereof.

The crusher 20 has a crusher body 22, a connecting portion 24, a pair of crushing arms 26, and a pair of open / close drive cylinders 28 as shown in FIGS.

The crusher body 22 and the connecting portion 24 are integrally connected. The connecting portion 24 is a portion that is rotatably connected to a tip end portion of the arm 16 and a rod side end portion of the crusher cylinder 19 via a crusher pin and a crusher cylinder pin, respectively.

Pin holes

24a and 24b that allow the pin and the crusher cylinder pin to be inserted are provided.

Each of the pair of crushing arms 26 corresponds to a pinching processing member, and rotates in the opening / closing direction, that is, in the direction of contacting / separating each other, between a closed position as shown in FIG. 2 and an open position as shown in FIG. The crusher body 22 is connected to the crusher body 22 as possible. Specifically, each of the pair of crushing arms 26 has an inner connecting portion, and the inner connecting portion can be rotated around a pin 27 provided at a tip portion of the crusher main body 22. The main body 22 is connected to the tip portion. The pair of crushing arms 26 have an inner edge including a plurality of crushing blades 26a, and are configured such that the crushing blades 26a sandwich and crush the object to be processed in a closed position as shown in FIG. .

Each of the pair of opening / closing drive cylinders 28 is constituted by a hydraulic cylinder that can be extended and contracted, and by the expansion and contraction, the crushing arm 26 is moved from the opening position to the closing position by a closing operation that is a closing direction and from the closing position. The crusher body 22 and the pair of crushing arms 26 are respectively interposed so as to perform an opening operation that is an operation in an opening direction toward the opening position.

Each open / close drive cylinder 28 includes a cylinder body 30 as shown in FIG. 4, a piston 34 that divides the cylinder body 30 into a head side chamber 32 </ b> H and a rod side chamber 32 </ b> R, and extends from the piston 34 in the axial direction. Rod 36. The cylinder body 30 is formed with a first port 30a that communicates with the head side chamber 32H and a second port 30b that communicates with the rod side chamber 32R. The opening / closing drive cylinder 28 discharges the hydraulic oil in the rod side chamber 32R through the second port 30b while extending as the hydraulic oil is supplied into the head side chamber 32H through the first port 30a. On the contrary, the opening / closing drive cylinder 28 contracts the hydraulic oil in the head side chamber 32H through the first port 30a while contracting when the hydraulic oil is supplied into the rod side chamber 32R through the second port 30b. Discharge.

As shown in FIGS. 2 and 3, the crushing arm connecting portion 40 protrudes from each head side end portion (lower end portion in FIGS. 2 and 3) of the cylinder body 30 of the pair of opening / closing drive cylinders 28, The crushing arm connecting portion 40 is connected to the outer end portions of the pair of crushing arms 26 via a pin 42 so as to be rotatable. On the other hand, the ends of the rods 36 of the pair of opening / closing drive cylinders constitute a crusher body connecting portion 46, and the crusher body connecting portion 46 is pivotable via a pin 48 so that the base of the crusher body 22 can be rotated. It is connected to an end, that is, an end near the connecting portion 24. Accordingly, the pair of open / close drive cylinders 28 extend simultaneously to rotate the pair of crushing arms 26 in the closing direction, and conversely contract simultaneously to rotate the pair of crushing arms 26 in the opening direction. Move.

The crushing device includes a main drive unit 50, an auxiliary drive unit 60, and a controller 80 as shown in FIG. 4 in addition to the crusher 20 corresponding to the sandwiching device main body. FIG. 4 shows only one opening / closing drive cylinder 28 of the pair of opening / closing drive cylinders 28 for convenience.

The main drive unit 50 includes a main hydraulic pump 52, a control valve 54, and a remote control valve 56.

The main hydraulic pump 52 sucks and discharges hydraulic oil to be supplied to the open / close drive cylinders 28 from the tank. The main hydraulic pump 52 according to this embodiment is a variable displacement hydraulic pump, and the capacity (displacement volume) of the main hydraulic pump 52 by inputting a pump command signal to a regulator (not shown) included in the main hydraulic pump 52. As a result, the pump discharge flow rate, which is the flow rate of the hydraulic oil discharged from the main hydraulic pump 52, changes.

The control valve 54 is interposed between the main hydraulic pump 52 and the pair of open / close drive cylinders 28 so as to switch the supply direction of hydraulic oil from the main hydraulic pump 52 to the pair of open / close drive cylinders 28. Operates on. The control valve 54 is connected to the first port 30a of each open / close drive cylinder 28 via a first supply line 55A, and to the second port of each open / close drive cylinder 28 via a second supply line 55B. Connected. The pair of open / close drive cylinders 28 is provided to the main hydraulic pump 52 and the control valve 54 so that the hydraulic oil discharged from the main hydraulic pump 52 is evenly distributed to the pair of open / close drive cylinders 28. Connected in parallel. Specifically, the first supply line 55A branches in a region close to the pair of opening / closing drive cylinders 28 to reach the first port 30a of each opening / closing drive cylinder 28, and the second supply line 55B is connected to the pair of opening / closing drive cylinders 28A. Branching in a region close to the drive cylinder 28 leads to the second port 30 a of each open / close drive cylinder 28.

In this embodiment, the control valve 54 is composed of a pilot-operated direction switching valve. The control valve 54 includes a neutral position 54n, a closing drive position 54a, and an opening drive position 54b according to the pilot pressure input to the control valve 54. Act to switch between. The control valve 54 shuts off the first and

second supply lines

55A and 55B and the open / close drive cylinders 28 connected thereto from the hydraulic pump 52 at the neutral position 54n. The control valve 54 supplies the hydraulic oil discharged from the main hydraulic pump 52 to the first port 30a of each open / close drive cylinder 28 through the first supply line 55A in the closed drive position 54a and the first drive line 54A. An oil passage is formed for guiding the hydraulic oil discharged to the second supply line 55B through the 2-port 30b to the tank. In contrast, at the opening drive position 54b, the control valve 54 supplies the hydraulic oil discharged from the main hydraulic pump 52 to the second ports 30b of the open / close drive cylinders 28 through the second supply line 55B. At the same time, an oil passage is formed that guides hydraulic oil discharged to the first supply line 55A through the first port 30a to the tank.

The control valve 54 has a pair of pilot ports, that is, a closing operation pilot port 53A and an opening operation pilot port 53B. The control valve 54 is maintained at the neutral position 54n when no pilot pressure is supplied to any of the closing operation and opening

operation pilot ports

53A, 53B. When a pilot pressure, that is, a closing operation pilot pressure Pa is supplied to the closing operation pilot port 53A, the control valve 54 is switched to the closing driving position 54a, and a pilot pressure, that is, an opening operation pilot pressure Pb is applied to the opening operation pilot port 53B. When supplied, it is switched to the opening drive position 54b.

The remote control valve 56 includes an operation lever 56a and a valve body 56b connected to the operation lever 56a.

The operation lever 56a is one mode of the operated part, and the operation lever 56a is given a closing operation and an opening operation for causing the pair of crushing arms 26 to perform the closing operation and the opening operation, respectively. . The closing operation is, for example, an operation of rotating the operation lever 56a in a specific direction, and the opening operation is, for example, an operation of rotating the operation lever 56a in a direction opposite to the specific direction.

The valve main body 56b is an embodiment of a valve operation part, and operates the control valve 54 in accordance with an operation given to the operation lever 56a which is the operated part. Specifically, the valve body 56b is interposed between a pilot hydraulic power source (not shown) and the closing operation pilot port 53A and the opening operation pilot port 53B of the control valve 54, and the closing operation and opening

operation pilot ports

53A and 53B. Are connected via a closing operation pilot line 57A and an opening operation pilot line 57B, respectively. The valve body 56b is opened to allow a pilot pressure (a closing operation pilot pressure Pa) to be supplied from the pilot hydraulic source through the closing operation pilot port 53A when the operation lever 56a is closed. When the opening operation is given to the operation lever 56a, the pilot hydraulic pressure source opens the pilot pressure (opening operation pilot pressure Pb) through the opening operation pilot port 53B.

The auxiliary driving unit 60 assists (increases) driving of the open / close driving cylinders 28 in the opening direction by the main driving unit 50, and includes a bypass oil passage 62, an auxiliary hydraulic pump 64, and a check. It has a valve 66, an open / close switching valve 68, and an auxiliary hydraulic pump drive device 70.

The bypass oil passage 62 communicates the first supply line 55A and the second supply line 55B with each other at a position closer to the pair of opening / closing drive cylinders 28 than the control valve 54. 2 connected to supply

lines

55A and 55B. Accordingly, the bypass oil passage 62 bypasses the control valve 54 and communicates the first port 30a and the second port 30b of each open / close drive cylinder 28 with each other. The bypass oil passage 62 according to this embodiment is connected to a portion of the first supply line 55A that is closer to the control valve 54 than the position where the first supply line 55A branches toward the opening / closing drive cylinders 28. And an upstream end connected to a portion of the second supply line 55B closer to the control valve 54 than a position where the second supply line 55B branches toward the opening / closing drive cylinders 28. And having.

The auxiliary hydraulic pump 64 is provided in the middle of the bypass oil passage 62, and is driven by the auxiliary hydraulic pump driving device 70 so that the hydraulic oil is discharged to the first supply line 55A through the first port 30a. Is operated in such a direction as to supply a part thereof to the second port 30b through the bypass oil passage 62 and the second supply line 55B. The check valve 66 is provided at a position downstream of the auxiliary hydraulic pump 64 in the bypass oil passage 62 and extends from the second port 30b and the second supply line 55B to the first supply line 55A and the first supply line 55B. The flow of hydraulic oil toward the port 30a, that is, the backflow is prevented.

The opening / closing switching valve 68 is provided at a position upstream of the auxiliary hydraulic pump 64 in the bypass oil passage 62, and the shut-off state for interrupting the flow of the hydraulic oil in the bypass oil passage 62 and the bypass oil passage 62 are provided. It functions as an oil passage opening and closing section that is opened and switched to an allowable state that allows the hydraulic oil to flow. The open / close switching valve 68 according to this embodiment is an electromagnetic switching valve having a solenoid 67, and is held at a blocking position 68s that blocks the bypass oil passage 62 when no opening command signal is input to the solenoid 67. When the opening command signal is input to the solenoid 67, the bypass oil passage 62 is opened to switch to the permissible position 62a that allows the hydraulic oil to flow.

The auxiliary drive unit 60 according to this embodiment further has a circulation oil path 65. The circulation oil passage 65 branches from the bypass oil passage 62 at a position between the auxiliary hydraulic pump 64 and the check valve 66, and a part of the hydraulic oil discharged from the auxiliary hydraulic pump 64 is supplied to the auxiliary oil pump 64. It is formed so as to return to the suction port of the hydraulic pump 64.

In this embodiment, a part of the circulating oil passage 65 is constituted by the opening / closing switching valve 68. Specifically, the open / close switching valve 68 is an oil passage corresponding to a downstream portion of the circulating oil passage 65 at the shut-off position 68s, and connects the upstream portion of the circulating oil passage 65 and the bypass oil passage 62. Form an oil passage to connect. On the other hand, the open / close switching valve 68 shuts off the upstream portion of the circulating oil passage 65 and the bypass oil passage 62 at the permissible position 68a. That is, the circulating oil passage 65 is shut off.

The auxiliary pump drive device 70 includes a pump drive motor 72, a battery 74, and an inverter 76. The pump drive motor 72 is an electric motor having an output shaft, and the output shaft is connected to the input shaft of the auxiliary hydraulic pump 64. The pump drive motor 72 operates by receiving supply of motor current from the battery 74 through the inverter 76 to drive the auxiliary hydraulic pump 64. The inverter 76 changes the motor current flowing through the auxiliary hydraulic pump 64 in accordance with the magnitude (command current) of the motor current command signal input to the inverter 76.

In this embodiment, the bypass oil passage 62, the auxiliary hydraulic pump 64, the check valve 66, the opening / closing switching valve 68 and the pump drive motor 72 constitute an auxiliary drive unit 69, and the auxiliary drive unit 69 is The work arm 10 is attached to an appropriate position. The position of the auxiliary drive unit 69 is, for example, as shown in FIG. 1, closer to the tip than the middle position in the longitudinal direction of the work arm 10, and as shown by the two-dot chain line in FIG. The position on the surface facing downward with the tip of the arm 10 facing forward, that is, the position on the abdominal surface of the arm 16 in the working arm 10 shown in FIG. This position reduces the distance between the auxiliary drive unit 69 and the opening / closing drive cylinder 28 of the crusher 20 attached to the tip, and suppresses pressure loss associated with the circulation of hydraulic oil by the auxiliary drive unit 69. There is an advantage that the auxiliary drive unit 69 can be easily viewed by an operator who operates the upper swing body 4.

The crushing apparatus according to this embodiment further includes a plurality of sensors. The plurality of sensors include a closing operation pilot pressure sensor 58A and an opening operation pilot pressure sensor 58B, which are a pair of pilot pressure sensors, and a rod side pressure sensor 59. The closing operation and opening operation

pilot pressure sensors

58A and 58B are supplied from the remote control valve 56 to the closing operation pilot port 53A through the closing operation pilot line 57A and from the remote control valve 56 to the opening operation pilot pressure Pa. The opening operation pilot pressure Pb supplied to the opening operation pilot port 53B through the operation pilot line 57B is detected, and an electrical signal corresponding to the pilot pressure, that is, a pilot pressure detection signal is generated. The rod side pressure sensor 59 is provided, for example, in the second supply line 55B, detects the rod side pressure that is the pressure in the rod side chamber 32R of the open / close drive cylinder 28, and an electrical signal corresponding to the rod side pressure, that is, the rod side pressure. A detection signal is generated.

The pair of

pilot pressure sensors

58A and 58B and the rod side pressure sensor 59 are connected to the controller 80, and input the pilot pressure detection signal and the rod side pressure detection signal to the controller 80, respectively.

The controller 80 is composed of, for example, a microcomputer. Based on the detection signals input to the controller 80, the capacity of the main hydraulic pump 52, the motor current flowing through the pump drive motor 72, and the open / close switching valve 68 are opened and closed. Control the behavior. Specifically, the controller 80 includes an opening operation determination unit 82, a main hydraulic pump control unit 84, an auxiliary hydraulic pump drive control unit 86, and an open / close switching control unit 88 as shown in FIG.

The opening operation determination unit 82 is configured to use the pair of crushing arms based on the opening operation pilot pressure Pb detected by the opening operation pilot pressure sensor 58B and the rod side pressure Pr detected by the rod side pressure sensor 59. It is determined whether or not 26 is opening, that is, rotating in the opening direction, and constitutes an opening operation detector together with the

sensors

58A, 58B, and 59. Specifically, the opening movement determination unit 82 determines that the crushing arm 26 is opening only when both of the following conditions (i) and (ii) are satisfied.
(I) The opening operation pilot pressure Pb exceeding a certain level is detected by the opening operation pilot pressure sensor 58B.
(Ii) The rod side pressure Pr detected by the rod side pressure sensor does not reach a preset upper limit pressure (for example, relief pressure) Pm (Pr <Pm).

The conditions (i) and (ii) are set because when the opening operation pilot pressure Pb is supplied from the remote control valve 56 to the control valve 54, the control valve 54 is switched to the opening drive position 54b. Therefore, it can be estimated that hydraulic fluid for moving the pair of crushing arms 26 in the opening direction is supplied to the opening / closing drive cylinder 28. However, when the rod side pressure Pr reaches the upper limit pressure Po, the opening / closing operation is performed. This is because it can be estimated that the drive cylinder 28 has already made a full stroke in the contraction direction, which is the direction in which the pair of crushing arms 26 perform the opening operation, and the opening operation has been completed.

The main hydraulic pump control unit 84 controls the discharge flow rate of the main hydraulic pump 52 by changing the capacity of the main hydraulic pump 52 by inputting a pump command signal to the regulator of the main hydraulic pump 52. The main hydraulic pump control unit 84 according to this embodiment increases the pump capacity of the main hydraulic pump 52 with the increase in the characteristic for performing so-called positive control, that is, the opening operation pilot pressure Pb, at least for the opening operation. For example, a map is stored, a pump command signal (pump command current Ip) corresponding to the input opening operation pilot pressure detection signal is calculated based on the map, and the pump command signal is calculated as the main hydraulic pressure. Input to the regulator of the pump 84.

The auxiliary hydraulic pump drive control unit 86 changes a motor current flowing through the pump drive motor 72 of the auxiliary hydraulic pump drive device 70 by inputting a motor current command signal to the inverter 76 of the auxiliary hydraulic pump drive device 70. Thus, the flow rate of the hydraulic oil flowing through the bypass oil passage 62 by changing the rotational speed of the auxiliary hydraulic pump 64, that is, a part of the hydraulic oil discharged from the first port 30a bypasses the control valve 54 and is A regeneration flow rate that is a flow rate re-supplied to the 2-port 30b is controlled. Similarly to the pump command signal, the auxiliary hydraulic pump drive control unit 86 according to this embodiment stores characteristics for increasing the motor current as the opening operation pilot pressure Pb increases, for example, as a map, A motor current command signal (motor current command current Im) corresponding to the input opening operation pilot pressure detection signal is calculated based on the map, and the motor current command signal is input to the inverter 76.

The opening / closing switching control unit 88 controls the position switching of the opening / closing switching valve 68 by inputting an opening command signal to the solenoid 69 of the opening / closing switching valve 68 and stopping the input. Specifically, the opening / closing switching control unit 88 inputs an opening command signal to the solenoid 69 of the opening / closing switching valve 68 only when the opening operation determining unit 82 determines that the opening operation is being performed. The opening / closing switching valve 68 is switched to the permissible position 68a, that is, the position allowing the hydraulic oil to flow through the bypass oil passage 62, and otherwise the input of the opening command signal is stopped and the opening / closing switching valve 68 is stopped. Is kept at the blocking position 68s.

Next, the operation of this crusher will be described.

In the circuit shown in FIG. 4, when the operation lever 56a of the remote control valve 56 is not operated and the operation lever 56a is maintained at the neutral position, the strokes of the pair of opening / closing drive cylinders 28 are fixed. The pair of crushing arms 26 connected to the pair of opening / closing drive cylinders 28 are fixed at their current positions. Specifically, when the operation lever 56a is in the neutral position, neither the closing operation pilot pressure Pa nor the opening operation pilot pressure Pb is output from the valve body 56b of the remote control valve 56, and thus the control valve 54 is in the neutral position 54n. The first and

second supply lines

55A and 55B are shut off from the main hydraulic pump 52. On the other hand, the auxiliary hydraulic pump drive control unit 86 of the controller 80 maintains the motor current command signal at the minimum value, maintains the motor current in the pump drive motor 72 at 0, and keeps the pump drive motor 72 in a stopped state. Further, the opening / closing switching control unit 88 of the controller 80 stops the input of the opening command signal to the solenoid 69 of the opening / closing switching valve 68 and causes the opening / closing switching valve 68 to flow through the shutoff position 68s, that is, the flow of the hydraulic oil in the bypass oil passage 62. Keep in the blocking position. Therefore, there is no supply / discharge of hydraulic oil in the open / close drive cylinder 28, and the open / close drive cylinder 28 is maintained in its current state.

When a closing operation is given to the operation lever 56a, the pair of opening / closing drive cylinders 28 are driven in the extending direction to cause the pair of crushing arms 26 to perform a closing operation. Specifically, the closing operation pilot pressure Pa is supplied from the valve main body 56b of the remote control valve 56 to the closing operation pilot port 53A of the control valve 54 through the closing operation pilot line 57A, whereby the control valve 54 is moved from the neutral position 54n. Switching to the closing drive position 54a connects the first supply line 55A to the main hydraulic pump 52 and the second supply line 55B to the tank. Accordingly, the hydraulic oil discharged from the main hydraulic pump 52 is supplied to the first port 30a of the open / close drive cylinder 28 through the first supply line 55A, and flows into the head side chamber 32H of the open / close drive cylinder 28. Thus, the opening / closing drive cylinder 28 is extended. Accordingly, the hydraulic oil in the rod side chamber 32R of the open / close drive cylinder 28 is discharged through the second port 30b and returned to the tank through the second supply line 55B and the control valve 54.

Also in this closing operation, the auxiliary hydraulic pump drive control unit 86 of the controller 80 keeps the pump drive motor 72 in a stopped state, and the open / close switching control unit 88 keeps the open / close switching valve 68 at the shut-off position 68s. Further, the check valve 66 provided in the bypass oil passage 62 prevents the hydraulic oil discharged from the second port 30b from flowing backward in the bypass oil passage 62 toward the first supply line 55A.

On the other hand, when an opening operation is given to the operation lever 56a, the pair of opening / closing drive cylinders 28 are driven in the contraction direction to cause the pair of crushing arms 26 to perform an opening operation. Specifically, the opening operation pilot pressure Pb is supplied from the valve main body 56b of the remote control valve 56 to the opening operation pilot port 53B of the control valve 54 through the opening operation pilot line 57B, whereby the control valve 54 is moved from the neutral position 54n. Switching to the opening drive position 54b connects the second supply line 55B to the main hydraulic pump 52 and connects the first supply line 55A to the tank. Accordingly, the hydraulic oil discharged from the main hydraulic pump 52 is supplied to the second port 30b of the open / close drive cylinder 28 through the second supply line 55B, flows into the rod side chamber 32R of the open / close drive cylinder 28, and The open / close drive cylinder 28 is contracted. Along with this, the pair of crushing arms 26 are driven in the opening direction, and hydraulic oil in the head side chamber 32H of the opening / closing drive cylinder 28 is discharged through the first port 30a, and the first supply line 55A and the above-mentioned It is returned to the tank through the control valve 54.

In this opening operation, the controller 80 performs a control operation as shown in the flowchart of FIG.

First, the opening operation determination unit 82 of the controller 80 determines whether or not there is an opening operation (steps S1 and S2). Specifically, in the opening operation determination unit 82, the opening operation pilot pressure sensor 58B detects an opening operation pilot pressure Pb of a certain level or more (YES in step S1), and the rod side pressure Pr detected by the rod side pressure sensor 59 is detected. Is determined not to reach the preset upper limit pressure Pm (YES in step S2), it is determined that the opening operation is currently being performed. Based on this determination, the main hydraulic pump control unit 84, the open / close switching control unit 88, and the auxiliary hydraulic pump drive control unit 86 perform the following opening operation control (step S3).

The main hydraulic pump control unit 84 performs so-called positive control on the discharge flow rate of the main hydraulic pump 52 based on the opening operation pilot pressure Pb detected by the opening operation pilot pressure sensor 58B. Specifically, the main hydraulic pump control unit 84 calculates a pump command current Ip corresponding to the opening operation pilot pressure Pb based on, for example, a characteristic of the opening operation pilot pressure Pb−pump command current Ip stored as a map, The pump command current Ip is input to the regulator of the main hydraulic pump 52 (step S3A). As a result, the capacity of the main hydraulic pump 52 is operated, and the discharge flow rate of the main hydraulic pump 52 and thus the driving speed of the open / close drive cylinder 28 are controlled.

The opening / closing switching control unit 88 inputs an opening command signal to the solenoid 67 of the opening / closing switching valve 68 only when the opening operation is determined. As a result, the on-off switching valve 68 is switched from the previous shutoff position 68s to the permissible position 68a, and the working oil flows through the bypass oil passage 62, specifically, the working oil flows in a direction not restricted by the check valve 66. That is, the flow in the direction from the first supply line 55A toward the second supply line 55B is allowed.

The auxiliary hydraulic pump drive control unit 86 controls the driving speed of the auxiliary hydraulic pump 64 by the pump drive motor 72 based on the opening operation pilot pressure Pb. Specifically, the auxiliary hydraulic pump drive control unit 86 calculates the motor current command current Im corresponding to the opening operation pilot pressure Pb based on the characteristics of the opening operation pilot pressure Pb−motor current command current Im stored as a map, for example. The motor current command current Im is calculated and input to the inverter 76 of the auxiliary hydraulic pump driving device 70 (step S3C). As a result, the motor current flowing through the pump drive motor 72 and the corresponding rotational speed of the pump drive motor 72 are operated, and the discharge flow rate of the auxiliary hydraulic pump 64 driven by the pump drive motor 72, that is, through the first port 30a. A regeneration flow rate, which is a flow rate at which a part of the hydraulic oil discharged to the first supply line 55A is re-supplied to the second port 30b through the bypass oil passage 62 and the second supply line 55B, is controlled. The combination of the control of the regeneration flow rate and the control of the discharge flow rate of the main hydraulic pump 52 can appropriately increase the operating speed in the contraction direction of each open / close drive cylinder 28 and the drive speed in the opening direction of each crushing arm 26. To.

7 and 8 show the characteristics of the pump command current Ip and the motor current command current Im with respect to the opening operation pilot pressure Pb stored in the main hydraulic pump control unit 84 and the auxiliary hydraulic pump drive control unit 86, respectively. A first example and a second example are shown. In the first example, characteristics approximate to each other are set for the pump command current Ip and the motor current command current Im, and both the command currents Ip and Im rise from a common pilot pressure Pbo. In the second example, both characteristics are set such that the motor current command current Im rises at an opening operation pilot pressure Pb2 smaller than the opening operation pilot pressure Pb1 at which the pump command current Ip rises. The combination of the characteristics is based only on driving of the auxiliary hydraulic pump 64 in a situation where the opening operation given to the operation lever 56a of the remote control valve 56 is small and the supply of hydraulic oil at a large flow rate to the second port 30b is not required. It is possible to cause the supply of hydraulic oil to the second port 30b, thereby making the effect of reducing the pressure loss due to the supply of hydraulic oil from the main hydraulic pump 52 to the second port 30b more remarkable. To do.

On the other hand, when the application of the opening operation to the operation lever 56a is canceled and the opening operation pilot pressure sensor 58B does not detect the opening operation pilot pressure Pb above a certain level (NO in step S1), or When the rod side pressure Pr detected by the rod side pressure sensor 59 reaches the upper limit pressure Pm as the drive cylinder 28 is fully stroked in the contraction direction to complete the opening operation (NO in step S2), that is, it opens. When it is determined that the operation is stopped or finished, the opening operation control is canceled (step S4). Specifically, positive control for opening operation by the main hydraulic pump control unit 84, input of an opening command signal to the solenoid 69 of the open / close switching valve 68 by the open / close switching control unit 88, and the auxiliary hydraulic pump drive control unit Input of the motor current command signal to the inverter 76 by 86 is all stopped.

Stopping the input of the opening command signal returns the open / close switching valve 68 from the allowable position 68a to the original shut-off position 68s, and stopping the input of the motor current command signal is the auxiliary hydraulic pump 64 by the pump drive motor 72. Stop driving. The auxiliary hydraulic pump 64 may continue to rotate even after the drive is stopped and may suck in hydraulic fluid upstream of the auxiliary hydraulic pump 64 for a while, but is switched to the shut-off position 68s. The opening / closing switching valve 68 opens the circulation oil passage 65 for circulating the working oil downstream of the auxiliary hydraulic pump 64 to the suction port of the auxiliary hydraulic pump 64, thereby continuing the suction of the auxiliary hydraulic pump 64 for a while. It is possible to suppress the occurrence of cavitation.

Next, a crushing apparatus that is a pinching processing apparatus according to a second embodiment of the present invention will be described with reference to FIGS. Among the constituent elements included in the second embodiment, the same constituent elements as those included in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The crushing apparatus according to the second embodiment includes a crusher 20, a main drive unit 50, and an auxiliary drive unit 60 that are equivalent to the crusher 20, the main drive unit 50, and the auxiliary drive unit 60 according to the first embodiment. However, instead of the electric auxiliary hydraulic pump driving device 70 according to the first embodiment, a hydraulic auxiliary hydraulic pump driving device 90 is provided. The auxiliary drive unit 60 according to the second embodiment includes a hydraulic pilot type on / off switching valve 98 instead of the electromagnetic on / off switching valve 68 according to the first embodiment.

The auxiliary hydraulic pump drive device 90 includes a pump drive motor 92, a motor drive hydraulic pump 94, and a motor drive switching valve 96.

The pump drive motor 92 is a hydraulic motor having an output shaft, and the output shaft is connected to an auxiliary hydraulic pump 64 in the auxiliary drive unit 60. Accordingly, the operation of the pump drive motor 92 drives the auxiliary hydraulic pump 64 in the same manner as in the first embodiment, and the hydraulic oil in the bypass oil passage 62 from the first supply line 55A to the second supply line 55B. To form a flow.

The motor-driven hydraulic pump 94 is connected to an unillustrated engine, like the main hydraulic pump 52, and is driven by the engine to discharge hydraulic oil. The hydraulic oil is supplied to the pump drive motor 92 through the auxiliary supply line 91 and contributes to driving of the pump drive motor 92.

The motor drive switching valve 96 is provided in the middle of the auxiliary supply line 91 and switches between opening / closing of the auxiliary supply line 91. The motor drive switching valve 96 is a two-position pilot switching valve having a pilot port 95. When the pilot pressure is not supplied to the pilot port 95, the motor drive switching valve 96 is maintained at the shut-off position 96s. At the shut-off position 96s, the auxiliary supply line 91 is shut off and the motor drive pump 94 is connected to the pump. The supply of hydraulic oil to the drive motor 92 is blocked. When the pilot pressure is supplied to the pilot port 95, the motor drive switching valve 96 is switched from the shut-off position 96s to an allowable position 96a. At the allowable position 96a, the auxiliary supply line 91 is opened to drive the motor. The supply of hydraulic oil from the pump 94 to the pump drive motor 92 is allowed.

The open / close switching valve 98 is a two-position pilot switching valve having a pilot port 97, similar to the motor drive switching valve 96. The open / close switching valve 98 has a shut-off position 98s and a permissible position 98a in the same manner as the open / close switch valve 68 according to the first embodiment. The shut-off position 98s shuts off the bypass oil passage 62 and the auxiliary valve. The circulating oil passage 65 for circulating the hydraulic oil discharged from the hydraulic pump 64 to the suction port of the hydraulic pump 64 is opened, and the circulating oil passage 65 is shut off and the bypass oil passage 62 is opened at the permissible position 98a. Thus, the flow of the hydraulic oil in the bypass oil passage 62 is allowed. The open / close switching valve 98 is maintained at the shut-off position 98s when the pilot pressure is not supplied to the pilot port 97, and is switched to the allowable position 98a when the pilot pressure is supplied to the pilot port 97.

Pilot ports

97 and 99 of the motor drive switching valve 96 and the opening / closing switching valve 98 are connected in parallel to each other via a pilot line 93 to a pilot hydraulic power source (not shown), and a pilot operation valve 99 is placed in the middle of the pilot line 93. Provided. The pilot operation valve 99 performs simultaneous switching of the motor drive switching valve 96 and the opening / closing switching valve 98 and is composed of an electromagnetic switching valve having a solenoid 100. When the pilot pressure supply command signal is not input to the solenoid 100, the pilot operation valve 99 blocks the pilot line 93 by being maintained at the blocking position 99s, and the pilot pressure supply command signal is input to the solenoid 100. Then, the pilot line 93 is opened by switching from the shut-off position 99s to the allowable position 99a to allow the pilot pressure to be supplied from the pilot hydraulic power source to the

pilot ports

95 and 97.

The crushing apparatus according to the second embodiment includes a controller 80, and the controller 80 is equivalent to the opening operation determination unit 82 and the main hydraulic pump control unit 84 according to the first embodiment. The main hydraulic pump control unit 84 includes a pilot operation control unit 89 instead of the auxiliary hydraulic pump drive control unit 86 and the open / close switching control unit 88 according to the first embodiment.

The pilot operation control unit 89 constitutes an auxiliary hydraulic pump drive control unit and an open / close switching control unit in cooperation with the pilot operation valve 99. Specifically, the switching control unit 89 inputs the pilot pressure supply command signal to the solenoid 100 of the pilot operation valve 99 and stops the input, so that the pilot operation valve 99 corresponding to the determination result by the opening operation determination unit 82 is obtained. Thus, the pilot operation of the motor drive switching valve 96 and the opening / closing switching valve 98 is controlled. That is, when the opening operation determination unit 82 determines that the opening operation is not performed, the pilot operation control unit 89 stops the input of the pilot pressure supply command signal to the solenoid 100 of the pilot operation valve 99. Thus, the pilot operation valve 99 is kept at the shut-off position 99s, thereby shutting off the pilot pressure supply to the motor drive switching valve 96 and the open / close switching valve 98 and keeping them at the shut-off

positions

96s and 98s. Conversely, when the opening operation determination unit 82 determines that the opening operation is being performed, the pilot operation control unit 89 inputs a pilot pressure supply command signal to the solenoid 100 of the pilot operation valve 99. The pilot operation valve 99 is switched to the allowable position 99a to allow the pilot pressure to be supplied to the motor drive switching valve 96 and the opening / closing switching valve 98. As a result, the

valves

96 and 98 are switched to the

permissible positions

96a and 98a to allow the hydraulic oil to flow through the auxiliary drive line 95 and the bypass oil passage 62.

FIG. 11 shows the control operation of the controller 80 related to the opening operation. Similar to the first embodiment, the controller 80 performs the opening operation control only when the opening operation determination unit 82 determines that the opening operation is being performed (YES in steps S1 and S2). In this opening operation control, the pilot operation control unit 89 issues a pilot pressure supply command in place of the opening command (step S3B in FIG. 6) and the motor current command (step S3C in FIG. 6) according to the first embodiment ( Step S3D). That is, the pilot operation control unit 89 inputs a pilot pressure supply command signal to the solenoid 100 of the pilot operation valve 99 and switches the pilot operation valve 99 to the permissible position 99a. The supply of pilot pressure to the

pilot ports

95 and 97 of the valve 98 is permitted. As a result, the opening / closing switching valve 98 is switched to the permissible position 98a to permit the flow of hydraulic oil in the bypass oil passage 62, and the motor drive switching valve 96 is switched to the permissible position 96a to pump from the motor driving hydraulic pump 94 to the pump. The supply of hydraulic oil to the drive motor 92 is allowed. In response to the supply of the hydraulic oil, the pump drive motor 92 rotationally drives the auxiliary hydraulic pump 64 to regenerate the hydraulic oil for the opening operation through the bypass oil passage 62 as in the first embodiment, that is, the first A part of the hydraulic oil discharged through the first port 30a is re-supplied to the second port 30b through the bypass oil passage 62.

The driving speed of the auxiliary hydraulic pump 64 by the pump driving motor 92 according to the second embodiment is constant. For example, the pump driving switching valve 96 is constituted by a flow rate adjusting valve, or the pump driving motor 92 It is possible to change the rotational speed of the auxiliary hydraulic pump 64 and the pump flow rate corresponding to the auxiliary hydraulic pump 64 in the same manner as in the first embodiment.

The present invention is not limited to the embodiment described above. The present invention includes, for example, the following forms.
(A) About pinching processing apparatus The pinching processing apparatus which concerns on this invention is not restricted to the said crushing apparatus. The present invention can also be applied to an apparatus that performs other pinching processing, for example, simple gripping or pressing of waste.
(B) Open / Close Drive Actuator The open / close drive actuator according to the present invention is not limited to a hydraulic cylinder. The opening / closing drive actuator may be, for example, a hydraulic motor that rotates a pair of pinching processing members. The opening / closing drive actuator may be a single hydraulic cylinder established between a pair of sandwiching members, and may drive the pair of sandwiching members in the opening / closing direction by expansion / contraction of the hydraulic cylinder.
(C) Control valve The control valve according to the present invention is not limited to a pilot operated type. The control valve may be a manual switching valve, for example.
(D) Oil passage opening / closing section The oil passage opening / closing section according to the present invention is not limited to the opening /

closing switching valves

68 and 98 as shown in FIGS. The oil passage opening / closing section can be constituted by, for example, an auxiliary hydraulic pump itself. For example, when a motor brake is applied to the pump drive motor 72 shown in FIG. 4 and the opening operation is not performed, the output shaft of the pump drive motor 72 is braked by the motor brake, thereby being coupled to the output shaft. The auxiliary hydraulic pump 64 can also function as a shut-off valve.
(E) Circulating oil path The circulating oil path 65 is not essential. For example, when the capacity of the auxiliary hydraulic pump is small and the risk of cavitation due to suction of hydraulic oil accompanying rotation due to its inertia is low, the circulating oil passage 65 may be omitted. In addition, the circulation switching unit that opens and closes the circulation oil path does not necessarily have to be configured by the opening /

closing switching valves

68 and 98, and may be a dedicated switching valve provided separately from the opening /

closing switching valves

68 and 98. Good.
(F) Operated part and valve operating part When the pinch processing apparatus according to the present invention includes an operated part and a valve operating part, the operated part and the valve operating part are not limited to the remote control valve 56. The operated part and the valve operating part are supplied to a control valve, for example, an electric lever device that receives a closing operation and an opening operation and generates an operation signal that is an electric signal corresponding to the closing operation and an opening operation. The pilot pressure reducing valve that changes the pilot pressure may be combined with a pilot control unit that inputs a control signal to the electromagnetic proportional pressure reducing valve based on an operation signal output from the electric lever device. In this case, the opening operation determination unit can grasp the presence / absence of the opening operation based on the operation signal output by the electric lever signal.
(G) About Opening Operation Detection Unit The opening operation detection unit according to the present invention is not limited to the combination of the opening operation pilot pressure sensor, the rod side pressure sensor, and the opening operation determination unit as described above. For example, the opening operation detection unit may determine the opening operation based on a pressure difference between the head side pressure and the rod side pressure. Alternatively, a stroke sensor that detects the stroke of the opening / closing drive cylinder may be used.

As described above, there is provided a pinching processing device provided in a work machine having a work arm, which can increase the speed of pinching processing operation with a high degree of freedom without significantly increasing pressure loss.

According to this device, driving of the auxiliary hydraulic pump by the auxiliary hydraulic pump drive device can increase the drive in the opening direction of the pair of pinching processing members by the opening / closing drive actuator without significant pressure loss. Is possible. Specifically, the auxiliary hydraulic pump drive device drives the auxiliary hydraulic pump in a state where the oil passage opening / closing portion opens the bypass oil passage, so that the auxiliary hydraulic pump is connected to the first port of the opening / closing drive actuator. It is possible to directly supply a part of the hydraulic oil discharged from the main valve to the second port of the opening / closing drive actuator without passing through the control valve, whereby the flow rate of the hydraulic oil discharged from the main hydraulic pump It is possible to increase the operating speed of the opening / closing drive actuator and the operating speed in the opening direction of the pair of pinching members by increasing the flow rate of the hydraulic oil supplied to the second port without increasing the amount.

Further, since the auxiliary hydraulic pump is driven independently of the main hydraulic pump and forces the hydraulic oil to flow, it is not subject to application restrictions depending on the type or driving direction of the hydraulic actuator, The degree of freedom of setting is also high.

In addition, since the bypass oil passage communicates the first port and the second port at a position closer to the hydraulic actuator than the control valve, the pressure loss due to the circulation of hydraulic oil through the bypass oil passage is: Increase in pressure loss accompanying an increase in the discharge flow rate of the main hydraulic pump, that is, the main hydraulic pump mounted on the base of the work machine is incorporated into a pinching device attached to the tip of the work arm of the work machine. This is smaller than the pressure loss associated with an increase in the flow rate of hydraulic oil supplied through a long pipe to the opening / closing drive actuator.

For example, the oil passage opening and closing section opens the bypass oil passage by blocking the working oil flow in the bypass oil passage at a position upstream of the auxiliary hydraulic pump, and allows the working oil to flow. It is preferable to include an open / close switching valve that switches between the allowable positions. The on / off switching valve can prevent the hydraulic oil discharged from the first port from flowing into the suction port of the auxiliary hydraulic pump by switching to the shut-off position.

In this case, the sandwiching device includes a circulating oil path for returning a part of the hydraulic oil discharged from the auxiliary hydraulic pump to the suction port of the auxiliary hydraulic pump, a state where the circulating oil path is blocked, and a state where the circulating oil path is opened. It is preferable to further include a circulation switching unit that switches to The combination of the circulation oil passage and the circulation opening / closing section can suppress the occurrence of cavitation caused by the opening / closing switching valve blocking the bypass oil passage before the auxiliary hydraulic pump is completely stopped. To. For example, even if the bypass oil passage is shut off by the opening / closing switching valve and the driving of the auxiliary hydraulic pump by the auxiliary hydraulic pump driving device is simultaneously performed, the auxiliary hydraulic pump is moved by its inertia and is completely In the meantime, the auxiliary hydraulic pump continues to suck in hydraulic fluid between the auxiliary hydraulic pump and the open / close switching valve until the auxiliary hydraulic pump stops, and cavitation may occur. However, at this time, the circulation opening / closing part opens the circulation oil passage and allows a part of the hydraulic oil discharged from the auxiliary hydraulic pump to be returned to the suction port of the auxiliary hydraulic pump through the circulation oil passage. By doing so, it is possible to effectively suppress the cavitation.

The opening / closing switching valve may have both a function as the oil passage opening / closing part and a function as the circulation opening / closing part. For example, it is preferable that the opening / closing switching valve is configured to open the circulation oil passage at the shut-off position and to shut off the circulation oil passage at the permissible position. This makes it possible to simplify the apparatus by consolidating the function of the oil passage opening / closing section and the function of the circulation opening / closing section in the opening / closing switching valve, and also shutting off / opening the bypass oil path and the circulation oil path. It is possible to reliably synchronize the opening / closing of.

作動 Automatic control is possible for the operation of the auxiliary hydraulic pump drive device and the opening / closing switching of the oil passage opening / closing section. Specifically, the sandwiching device is provided with a closing operation and an opening operation for causing the pair of sandwiching processing members to perform a closing operation and an opening operation, which are operations in the closing direction and the opening direction, respectively. A valve operation unit that activates the control valve in accordance with an operation given to the operated portion, an opening operation detection unit that detects that the pair of pinching processing members is opening, and the opening operation An auxiliary hydraulic pump drive control unit that activates the auxiliary hydraulic pump drive device only when the opening operation is detected by the detection unit, and the oil passage opening / closing unit only when the operation is detected by the opening operation detection unit It is preferable to further include an open / close switching control unit that switches the switch to the open state. These components enable the supply of hydraulic oil from the main hydraulic pump to the opening / closing drive actuator to be automatically switched by an operation given to the operated part, and the pair of pinching processes An auxiliary supply of hydraulic oil from the first port to the second port through the bypass oil passage by opening the bypass oil passage and operating the auxiliary hydraulic pump drive device only when the member is in the opening operation. By performing the above, it is possible to suppress useless operation of the auxiliary hydraulic pump drive device.

When the open / close drive actuator is a hydraulic cylinder that expands and contracts within a limited stroke range, and the open / close drive cylinder operates the pair of pinching members in the closing direction and the opening direction by the expansion / contraction, the opening operation The detection unit, for example, an opening operation detection unit that detects that the opening operation is given to the operated part, and that the opening / closing drive cylinder has made a full stroke in a direction in which the pair of pinching processing members move in the opening direction. And the pair of pinching processing members perform the opening operation when the opening operation detecting unit detects the opening operation and the full stroke detecting unit does not detect the full stroke. It is possible to detect the proper opening movement by including the opening movement determination section that determines that That.

The auxiliary hydraulic pump drive controller controls the auxiliary hydraulic pump by the auxiliary hydraulic pump drive device so as to increase the flow rate of the hydraulic oil flowing through the bypass oil passage as the opening operation given to the operated portion increases. It is preferable to perform control to increase the driving speed. This control enables a speed increase that respects the will of the operator who performs the opening operation.

Further, when the main hydraulic pump is a variable displacement hydraulic pump, the pinch processing device changes the capacity of the main hydraulic pump so as to increase the discharge flow rate of the main hydraulic pump as the opening operation increases. It is preferable to further include a main hydraulic pump control unit. The combination of the main hydraulic pump control unit and the auxiliary hydraulic pump drive control unit enables the drive control of the open / close drive actuator.

For example, the auxiliary hydraulic pump drive control unit is configured to open the auxiliary hydraulic pump by the auxiliary hydraulic pump drive device with an opening operation smaller than an opening operation in which the main hydraulic pump control unit raises the capacity of the main hydraulic pump. Those that increase the driving speed are preferred. This control is performed by supplying hydraulic oil to the second port only by driving the auxiliary hydraulic pump when the opening operation is small and it is not necessary to supply hydraulic oil at a large flow rate to the second port. The effect of reducing the pressure loss can be made more remarkable.

Also provided is a work machine comprising a machine body, a work arm having a base end connected to the machine body, a work arm having a tip that can be displaced relative to the base end, and the pinching device. Is done. In this work machine, the pinch processing device main body and the opening / closing drive actuator of the pinch processing device can be moved relative to the base body over a wide range by being attached to the tip of the work arm. The bypass oil passage, the opening / closing switching unit, and the auxiliary hydraulic pump can follow the movements of the sandwiching device main body and the opening / closing drive actuator by being provided on the work arm, and the opening / closing By bypass-feeding part of the hydraulic oil discharged from the first port to the second port at a position close to the drive actuator, the pair of pinching members in the pinching device is effectively reduced while reducing pressure loss. The opening operation can be accelerated.

Specifically, the bypass oil passage, the opening / closing switching unit, and the auxiliary hydraulic pump constitute an auxiliary drive unit, and the auxiliary drive unit is closer to the tip than the intermediate position in the longitudinal direction of the work arm. And it is preferable that the front-end | tip part of the said work arm is provided in the surface which faces down in the attitude | position which faces the front. The auxiliary unit is provided at a position close to the tip of the working arm, so that the pressure loss can be further reduced and can be easily visually recognized by an operator in the machine body.

Claims

A pinch processing device provided in a work machine comprising a machine body, and a work arm having a base end connected to the machine and a distal end capable of relative displacement with respect to the base end,
A main body of a pinch processing apparatus attached to the tip of the working arm, and a pair of pinch processing members movable in an opening / closing direction contacting and separating from each other, and the pair of pinching processing members moving in the opening / closing direction Including an opening / closing drive actuator coupled to the pair of sandwiching processing members, the opening / closing drive actuator having a first port and a second port, and receiving the supply of hydraulic oil through the first port. The hydraulic oil is discharged through the second port while moving the pair of pinching members in the closing direction, and the supply of hydraulic oil through the second port is received to move the pair of pinching members in the opening direction. A hydraulic actuator that discharges hydraulic oil through the first port;
A main hydraulic pump that is mounted on the airframe and discharges hydraulic oil to be supplied to the opening / closing drive actuator;
It is interposed between the opening / closing drive actuator and the main hydraulic pump, and supplies hydraulic oil discharged from the main hydraulic pump to the first port and guides hydraulic oil discharged from the second supply port to the tank. A closed drive position that forms an oil passage, and an open drive that forms an oil passage that supplies hydraulic oil discharged from the main hydraulic pump to the second port and guides hydraulic oil discharged from the first supply port to the tank. A control valve that can be switched to a position;
A bypass oil passage that bypasses the control valve at a position closer to the open / close drive actuator than the control valve and communicates the first port and the second port of the open / close drive actuator with each other;
An oil passage opening and closing portion that can be switched between a shut-off state that interrupts the flow of the hydraulic oil in the bypass oil passage and an allowable state that opens the bypass oil passage and permits the flow of the hydraulic oil;
A check valve that prevents backflow of hydraulic oil from the second port toward the first port in the bypass oil passage;
An auxiliary hydraulic pump that operates to supply a part of the hydraulic oil discharged from the first port to the second port through the bypass oil passage;
An auxiliary hydraulic pump driving device that drives the auxiliary hydraulic pump.
2. The sandwiching device for a work machine according to claim 1, wherein the oil passage opening and closing section is configured to shut off a flow of hydraulic oil in the bypass oil passage at a position upstream of the auxiliary hydraulic pump and the bypass oil. A pinch processing device for a work machine, including an open / close switching valve that switches between an allowable position that allows passage of the hydraulic oil by opening a path.
The pinch processing device for a work machine according to claim 2, wherein the pinch processing device includes a circulating oil path for returning a part of the hydraulic oil discharged from the auxiliary hydraulic pump to a suction port of the auxiliary hydraulic pump, A pinch processing device for a work machine, further comprising: a circulation switching unit that switches between a state in which the circulation oil passage is blocked and a state in which the circulation oil passage is opened.
4. The work machine pinching apparatus according to claim 3, wherein the on-off switching valve opens the circulation oil passage at the shut-off position and shuts off the circulation oil passage at the permissible position. apparatus.
5. The sandwiching device for a work machine according to claim 1, wherein the pair of sandwiching processing members perform a closing operation and an opening operation, which are operations in the closing direction and the opening direction, respectively. The operated part to which the closing operation and the opening operation are given, the valve operating part that operates the control valve according to the operation given to the operated part, and the pair of pinching processing members are performing the opening operation. An opening operation detection unit to detect, an auxiliary hydraulic pump drive control unit that operates the auxiliary hydraulic pump drive device only when the opening operation is detected by the opening operation detection unit, and the operation by the opening operation detection unit. A pinch processing device for a work machine, further comprising: an open / close switching control unit that switches the oil passage opening / closing unit to the open state only when it is detected.
6. The pinch processing device for a work machine according to claim 5, wherein the opening / closing drive actuator is a hydraulic cylinder that expands and contracts within a limited stroke range, and the pair of pinch processing members are moved in the closing direction by the expansion and contraction. An opening / closing drive cylinder that is actuated in an opening direction, wherein the opening motion detection unit is configured to detect that the opening operation is given to the operated part, and the opening / closing drive cylinder includes the pair of pinching processes. A full stroke detection unit that detects a full stroke in the direction in which the member is moved in the opening direction, and the opening operation detection unit detects the opening operation and the full stroke detection unit does not detect the full stroke. An opening motion determination unit that determines that the pair of clamping processing members are performing the opening motion. Processing apparatus.
The sandwiching device for a work machine according to claim 5 or 6, wherein the auxiliary hydraulic pump drive control unit is configured to supply hydraulic fluid that flows through the bypass oil passage as the opening operation given to the operated unit increases. A sandwiching device for a work machine that performs control to increase a driving speed of the auxiliary hydraulic pump by the auxiliary hydraulic pump driving device so as to increase a flow rate.
8. The sandwiching apparatus for a work machine according to claim 7, wherein the main hydraulic pump is a variable displacement hydraulic pump, and the sandwiching apparatus increases a discharge flow rate of the main hydraulic pump as the opening operation increases. A work machine pinching processing device further comprising a main hydraulic pump control unit that changes a capacity of the main hydraulic pump so as to cause the main hydraulic pump to change.
9. The sandwiching device for a work machine according to claim 8, wherein the auxiliary hydraulic pump drive control unit is smaller in opening operation than the opening operation in which the main hydraulic pump control unit raises the capacity of the main hydraulic pump. A work machine pinching device for raising the drive speed of the auxiliary hydraulic pump by the auxiliary hydraulic pump drive device.
The aircraft,
A work arm having a base end connected to the airframe and a front end capable of relative displacement with respect to the base end;
A work machine pinching device according to any one of claims 1 to 9,
The pinch processing device main body and the opening / closing drive actuator of the pinching processing device are attached to the tip of the working arm, and the bypass oil passage, the opening / closing switching unit, and the auxiliary hydraulic pump are provided on the working arm, Work machine.
The work machine according to claim 10, wherein the bypass oil passage, the opening / closing switching unit, and the auxiliary hydraulic pump constitute an auxiliary drive unit, and the auxiliary drive unit is located at an intermediate position in the longitudinal direction of the work arm. A work machine provided on a surface facing downward with a position close to the tip and the tip of the work arm facing forward.