JP5211216B2 - Hydraulic drive device and pinch processing device equipped with the same - Google Patents

Description

  The present invention relates to a technique for driving a pinching device such as a crusher or a press by a hydraulic actuator such as a hydraulic cylinder.

  2. Description of the Related Art Conventionally, as a pinching processing device that is opened and closed using a hydraulic actuator, for example, a crusher that is attached to the tip of an attachment support portion of a work machine is known. The crusher includes a crusher main body attached to the attachment support portion and a pair of crushing arms rotatably connected to the crusher main body, and the crushing arms rotate in directions opposite to each other. Open and close by. And at the time of the operation | movement of the closing direction, a processed material is inserted | pinched between the said crushing arms, and this is crushed.

  The hydraulic actuator is used to open and close the crushing arm. The higher the driving speed, the higher the working efficiency, and the greater the driving force, the better the crushing performance. In general, when the driving load is small, for example, when the crushing arm is opened, a high driving speed is required. Conversely, when the driving load is large, that is, when the crushing process is performed, a large driving force is required. However, the driving speed and driving force of the hydraulic actuator and the crushing arm are determined by the capacity and discharge pressure of a hydraulic pump that supplies hydraulic oil to the hydraulic actuator. Therefore, in order to obtain a higher driving speed and a larger driving force with the limited pump capacity and pump discharge pressure, it is necessary to interpose a speed increaser and a pressure booster between the hydraulic pump and the hydraulic actuator. It becomes.

  As a specific means thereof, for example, Patent Literature 1 below discloses a hydraulic drive device including a pressure intensifier using a hydraulic cylinder. The intensifier disclosed in FIG. 1 of the document 1 has two working chambers having different cross-sectional areas, and each working chamber is loaded with a piston having a size corresponding to the cross-sectional area of the working chamber. . In this device, hydraulic oil discharged from the hydraulic pump is introduced into the large-area working chamber among the two working chambers of the pressure intensifier, so that the hydraulic oil whose pressure has been increased from the small-area working chamber is pushed out. Then, it is supplied to a hydraulic actuator (drive cylinder 14 in the literature 1).

JP-A-62-83504

  In the pressure intensifier shown in Patent Document 1, when the capacity of the large-area working chamber is maximized, the oil discharged from the hydraulic pump cannot be further introduced into the working chamber. Therefore, after that, the position of each piston of the pressure intensifier must be returned to the original by some means, which is inefficient. Moreover, in order to lengthen the period during which pressure can be increased by this pressure booster, there is a disadvantage that the pressure booster must be enlarged.

  In view of such circumstances, the present invention provides a hydraulic drive device capable of continuously performing pressure increasing drive over a long period of time without significantly increasing the size of the device, and a pinching processing device using the same. For the purpose.

  As means for solving the above-mentioned problems, the present invention is a hydraulic drive device comprising a hydraulic actuator, a hydraulic pump, and a hydraulic circuit that connects the hydraulic pump to the hydraulic actuator and operates the hydraulic actuator. The hydraulic circuit includes a pressure intensifier for increasing a ratio of a driving force of the hydraulic actuator to a discharge pressure of the hydraulic pump, an introduction unit for introducing discharge oil of the hydraulic pump into the pressure intensifier, and the pressure intensifier. A supply section for supplying oil flowing out from the hydraulic actuator to the hydraulic actuator, and a return section for returning oil flowing out from the hydraulic actuator to the tank, wherein the pressure intensifiers are arranged in a first cylinder and a second cylinder aligned in the axial direction. A cylinder, an inner chamber on the side close to the second cylinder, and the other side of the first cylinder loaded in the first cylinder. A first piston that is partitioned into a side chamber, and is loaded into the second cylinder so that the inside of the second cylinder is partitioned into an inner chamber on the side close to the first cylinder and an outer chamber on the opposite side. The second piston, the first piston and the second piston are connected to each other, and these pistons are interlocked with each other, and due to the presence, the cross-sectional area of the inner chamber is made larger than the cross-sectional area of the outer chamber. A connecting member for reducing the size, and the introduction portion includes introduction switching means for alternately switching the introduction destination of the discharge oil of the hydraulic pump between the outer chamber of the first cylinder and the outer chamber of the second cylinder. The supply section includes oil passages for guiding oil flowing out from the inner chamber of the first cylinder and oil flowing out of the inner chamber of the second cylinder to the hydraulic actuator.

  In this apparatus, since the discharge oil of the hydraulic pump is alternately introduced into the inner chambers of both cylinders in the pressure booster, the pressure boosting operation by the pressure booster is continuously performed over a long period of time even if the volume of each cylinder is small. be able to. For example, when the discharge oil of the hydraulic pump is introduced into the outer chamber of the first cylinder of both cylinders and the volume of the outer chamber approaches the maximum volume, the volume of the outer chamber of the second cylinder decreases. Therefore, the speed increasing operation by the pressure intensifier is continued as it is by switching the introduction destination of the discharge oil from the outer chamber of the first cylinder to the outer chamber of the second cylinder at an appropriate time. Is possible.

  Further, the introduction switching means has a first introduction position for guiding the discharge oil of the hydraulic pump to the outer chamber of the first cylinder, and a second position for guiding the discharge oil of the hydraulic pump to the outer chamber of the second cylinder. An introduction switching valve having a first introduction position, and when the volume of the outer chamber of the first cylinder falls below a certain level, the position of the introduction switching valve is switched to the first introduction position, and the second hydraulic pressure is changed. Valve operating means for switching the position of the introduction switching valve to the second introduction position when the volume of the outer chamber of the cylinder becomes equal to or less than a certain value.

  Thereby, the introduction switching valve can be switched with a simple configuration using oil in each cylinder. That is, when the volume of the outer chamber of the first cylinder becomes below a certain level, the oil in the first cylinder or the second cylinder is guided to the first pilot portion of the introduction switching valve. Thus, the introduction switching valve is automatically switched to the first introduction position, and conversely, when the volume of the outer chamber of the second hydraulic cylinder becomes below a certain level, the oil in the second hydraulic cylinder is reduced. Alternatively, the introduction switching valve is automatically switched to the second introduction position when the oil in the first cylinder is guided to the second pilot section.

  Specifically, the introduction switching valve includes a first pilot portion to which a pilot pressure for switching the introduction switching valve to the first introduction position is input, and the introduction switching valve to the second introduction position. A pilot switching valve having a second pilot section to which a pilot pressure for switching is input, and the valve operating means is configured such that when the volume of the outer chamber of the first cylinder becomes equal to or less than a predetermined value, When the oil in the cylinder or the second cylinder is guided to the first pilot section, and the volume of the outer chamber of the second hydraulic cylinder becomes equal to or less than a certain value, the oil in the second hydraulic cylinder Or the oil in the first cylinder to the second pilot part is preferred.

  Thereby, the introduction switching valve can be switched with a simple configuration using oil in each cylinder. That is, when the volume of the outer chamber of the first cylinder becomes below a certain level, the oil in the first cylinder or the second cylinder is guided to the first pilot portion of the introduction switching valve. Thus, the introduction switching valve is automatically switched to the first introduction position, and conversely, when the volume of the outer chamber of the second hydraulic cylinder becomes below a certain level, the oil in the second hydraulic cylinder is reduced. Alternatively, the introduction switching valve is automatically switched to the second introduction position when the oil in the first cylinder is guided to the second pilot section.

Here, the valve operating means includes a first pilot oil passage communicating the first pilot part and the first cylinder or the second cylinder, the second pilot part, and the second pilot part. A second pilot oil passage communicating with the inside of the first cylinder or the second cylinder, and a position facing the inside of the first cylinder or the second cylinder, wherein the first pilot oil passage is While being held at the closing position, when the volume of the outer chamber of the first cylinder becomes equal to or less than a certain level, the first pilot oil passage is opened by receiving the pressure of the first piston or the second piston. A first on-off valve that opens, a position facing the first cylinder or the second cylinder and closing the second pilot oil passage; and an outer side of the second cylinder Room size There those containing a second on-off valve to open said second pilot oil passage by receiving the pressing of the first piston or the second piston when a predetermined value or less is suitable.

  According to this configuration, the introduction switching valve can be switched reliably using the reciprocating motion of the piston in each cylinder. That is, when the volume of the outer chamber of the first cylinder becomes equal to or less than a certain value, the first on-off valve receives the pressing force of the first piston or the second piston and moves the first pilot oil passage. By opening, the pilot pressure is introduced from the pressure intensifier to the first pilot portion of the introduction switching valve to switch the introduction switching valve to the first introduction position, while the volume of the outer chamber of the second cylinder is increased. When the second on-off valve receives the pressure of the first piston or the second piston to open the second pilot oil passage when the pressure becomes less than a certain value, the introduction switching valve from the pressure booster The pilot pressure is introduced into the second pilot portion of the engine, and the introduction switching valve is switched to the second introduction position.

  More preferably, the supply unit of the apparatus includes a direction switching valve that switches a port of the hydraulic actuator that supplies oil flowing out from the speed increaser to switch an operation direction of the hydraulic actuator.

  The present invention also includes a first sandwiching member and a second sandwiching member that move relative to each other in the opening / closing direction, which is a direction in which they are contacted and separated from each other, and sandwich the workpiece when moved in the closing direction, and drive the opening / closing of these sandwiching members. The hydraulic drive device according to any one of claims 1 to 4 is provided, and when the hydraulic actuator of the hydraulic drive device is operated, the sandwiching members are moved relative to each other in the opening / closing direction. And a hydraulic actuator of the hydraulic drive device.

  According to this device, by using the speed increaser or pressure booster of the hydraulic drive device, the hydraulic actuator is continuously driven to increase or decrease pressure, thereby quickly opening and closing both the sandwiching members, Or it can be opened and closed with a large driving force.

  As the sandwiching apparatus, each of the sandwiching members is a crusher that is a crushing member that crushes the processed product by sandwiching the processed product therebetween, or a press device that presses the processed product between molds. Etc. can be applied.

  In addition, the device having a crushing member as the pinching member includes a device main body connected so that each of the pinching members can be relatively moved in the opening and closing direction, and the device main body includes an attachment whose tip is movable. What has an attachment part attached to the front-end | tip of the said attachment support part of the working machine provided with a support part is suitable. According to this structure, the said pinching processing apparatus can be smoothly transferred to a process target by the action | operation of the said attachment support part.

  Further, the present invention provides an attachment support portion having a tip attached to the attachment processing device, an attachment portion to which an attachment portion of the device main body of the attachment processing device is attached, and the attachment support portion is movable at the tip of the attachment support portion. A work machine in which a hydraulic circuit of the pinch processing device and a hydraulic pump connected to the hydraulic circuit are mounted on the machine body or the attachment support part.

  As described above, according to the present invention, it is possible to continuously perform the speed increasing drive and the pressure increasing drive for a long time without particularly increasing the capacity of the pressure booster using the area difference in the cylinder. There is.

It is a general view which shows the example of the working machine with which the crusher which concerns on this invention is used. It is a front view of the crusher. It is a circuit diagram showing a hydraulic drive concerning a reference form of the present invention. It is a circuit diagram which shows the principal part of the said hydraulic drive device. It is a circuit diagram which shows the pilot oil path of the speed up gear shown by FIG. It is a circuit diagram which shows the principal part of the hydraulic drive device which concerns on embodiment of this invention. It is a circuit diagram which shows the pilot oil path of the pressure booster shown by FIG.

  First, a reference embodiment different from the embodiment of the present invention will be described with reference to FIGS.

  The work machine shown in FIG. 1 includes a machine body 10 capable of traveling and an attachment support portion. This attachment support part is comprised by the boom 12 provided in the said body 10 so that raising and lowering is possible, and the arm 14 connected with the front-end | tip of this boom 12 so that rotation about a horizontal axis is possible. The distal end of the arm 14 can be freely moved by combining the raising and lowering operation of the boom 12 and the rotation operation of the boom 12 and the rotation operation of the arm 14. And the crusher 16 is attached to the front-end | tip of this arm 14 so that rotation around a horizontal axis is possible and detachable.

  As shown in FIG. 2, the crusher 16 includes a crusher body 20. The crusher main body 20 includes an arm connecting portion 18 attached to the tip of the arm 14 and a support column portion 24 connected to the arm connecting portion 18 via a rotation drive mechanism 19 so as to be relatively rotatable.

  The rotation drive mechanism 19 relatively rotates a pair of disk-shaped substrates 22, 30 around its central axis, and the column portion 24 is erected on one of the substrates 22, and the other substrate 30 is The arm connecting portion 18 is erected.

  A first crushing arm 28 </ b> A and a second crushing arm 28 </ b> B are connected to the distal end of the support column 24 so as to be rotatable through left and right support shafts 26, respectively. These crushing arms 28A and 28B have a crushing blade 27 inside thereof.

  A first hydraulic cylinder 40A is interposed between the first crushing arm 28A and the substrate 22. Similarly, a second hydraulic cylinder 40B is interposed between the second crushing arm 28B and the substrate 22. These hydraulic cylinders 40A and 40B simultaneously expand and contract to rotate the crushing arms 28A and 28B in opposite directions. That is, the crushing arms 28A and 28B are caused to perform an opening / closing operation (crushing operation).

  On the other hand, the arm connecting portion 18 has a pair of brackets 32 protruding from the substrate 30, and through holes 34 and 36 are provided in these brackets 32. Of these, a pin for connecting the bracket 32 to the tip of the arm 14 is inserted into the through hole 34, and a cylinder 38 for driving the crusher to rotate the bracket 32 is inserted into the through hole 36 (FIG. 1). ) Is inserted through the pin.

  As shown in FIG. 3, each of the hydraulic cylinders 40 </ b> A and 40 </ b> B includes a cylinder body 42, a piston 43 loaded in the cylinder body 42, and a rod 44 extending from the piston 43 to one side. The piston 43 partitions the inside of the cylinder body 42 into the rod side chamber 45 and a head side chamber 46 on the opposite side.

  FIG. 3 shows a hydraulic drive apparatus including the hydraulic cylinders 40A and 40B. Although the drawing shows both hydraulic cylinders 40A and 40B in common for the sake of convenience, both hydraulic cylinders 40A and 40B are actually connected in parallel to the illustrated hydraulic circuit. Further, the hydraulic drive device according to the present invention can be applied to a device having only a single hydraulic actuator.

The illustrated hydraulic drive device includes, in addition to the hydraulic cylinders 40A and 40B, a hydraulic pump 50 and a hydraulic circuit for connecting the hydraulic cylinders 40A and 40B to the hydraulic pump 50. The hydraulic pump 50 is connected to an output shaft of an unillustrated engine mounted on the body 16 and is driven by the engine to discharge hydraulic oil in a tank. The hydraulic circuit supplies oil discharged from the hydraulic pump 50 to the hydraulic cylinders 40A and 40B to operate both hydraulic cylinders simultaneously.

  The hydraulic circuit includes a speed increaser 52, an introduction oil passage 54 for introducing oil discharged from the hydraulic pump 50 into the speed increaser 52, and oil flowing out of the speed increaser 52 from the hydraulic cylinder 40A, A supply oil passage 56 for supplying to 40B and a return passage 58 for returning the oil flowing out from the hydraulic cylinders 40A, 40B to the tank are included.

  The speed increaser 52 is for increasing the ratio of the driving speed of the hydraulic cylinders 40A and 40B to the flow rate of the hydraulic pump 50, and includes a first cylinder 60A and a second cylinder 60B. 60A and 60B are integrated with each other in the axial direction.

  As also shown in FIG. 4, a first piston 62A is reciprocally loaded in the first cylinder 60A, and the first piston 62A passes through the first cylinder 60A in the second cylinder 60A. It is partitioned into an inner chamber 64A on the side close to the cylinder 60B and an outer chamber 66A on the opposite side. Similarly, a second piston 62B is reciprocably loaded in the second cylinder 60B, and the second piston 62B is located in the second cylinder 60B on the side close to the first cylinder 60A. It is partitioned into an inner chamber 64B and an outer chamber 66B on the opposite side.

  The pistons 62A and 62B are interconnected in a direction parallel to the axial direction of the cylinders 60A and 60B via a connecting rod 68. The connecting rod 68 passes through the partition wall 70 between the cylinders 60A and 60B, and both ends thereof are connected to the first piston 62A and the second piston 62B. The connecting rod 68 functions to make the pistons 62A and 62B interlock with each other and to make the cross-sectional area of the inner chambers 64A and 64B smaller than the cross-sectional area of the outer chambers 66A and 66B due to the presence of the connecting rod 68. Have.

  Here, the partition wall 70 is provided with inner ports 72A and 72B for supplying and discharging hydraulic oil to and from the inner chambers 64A and 64B, respectively. Similarly, outer ports 74A and 74B for supplying and discharging hydraulic oil to and from the outer chambers 66A and 66B are provided on the outer walls of the cylinders 60A and 60B.

  The introduction oil passage 54 is provided with a bypass switching valve 76 and an introduction switching valve 78 in order from the side closer to the hydraulic pump 50.

  The bypass switching valve 76 is a two-position pilot switching valve in the illustrated example, and has a normal position 76a and a bypass switching position 76b. The normal position 76a is a position where the introduction oil passage 54 is opened as it is, and the bypass switching position 76b is a position where the introduction oil passage 54 is blocked and the hydraulic pump 50 is connected to the bypass oil passage 80. The bypass oil passage 80 bypasses the speed increaser 52 and guides the oil discharged from the hydraulic pump 50 to the hydraulic cylinders 40A and 40B, and is supplied from the bypass output port of the bypass switching valve 76. It directly passes through the oil passage 56.

The bypass switching valve 76 is maintained at the normal position 76a by the urging force of the urging spring 77 when the pilot pressure is not supplied to the pilot port, whereas when the pilot pressure is supplied, the bypass switching valve 76 is moved to the bypass position 76b. Switched. The pilot port is connected to the primary side of the bypass switching valve 76 via a pilot line 82, and a variable relief valve 84 with a check valve is provided in the middle of the pilot line 82. The variable relief valve 84 with a check valve opens the pilot line 82 only when the pressure on the primary side, that is, the discharge pressure of the hydraulic pump 50 exceeds the set pressure of the relief valve 84. That is, the variable relief valve 84 with a check valve constitutes a forcible switching unit that forcibly switches the bypass switching valve 76 to the bypass position 76b when the discharge pressure is a certain level or more.

  The introduction switching valve 78 is constituted by a two-position pilot switching valve in the illustrated example, and has a first introduction position 78a and a second introduction position 78b. The first introduction position 78a is a position where the introduction oil passage 54 is connected to the inner port 72A of the speed increaser 52, and the inner port 72B of the speed increaser 52 is connected to the return oil passage 86 to the tank. is there. Conversely, the second introduction position 78b is a position where the introduction oil passage 54 is connected to the inner port 72B and the inner port 72A is connected to the return oil passage 86.

  The introduction switching valve 78 has a first pilot port 79A and a second pilot port 79B, and is switched to the first introduction position 78a when a pilot pressure is supplied to the first pilot port 79A. When the pilot pressure is supplied to the second pilot port 79B, the second introduction port 78b is switched to.

  In this reference mode, oil in the inner chambers 64A and 64B in the speed increaser 52 is used for pilot supply to the introduction switching valve 78, that is, pilot operation of the valve 78. Specifically, when the volume of the inner chamber 64A of the first cylinder 60A becomes equal to or less than a certain level, the oil in the inner chamber 64B on the opposite side is guided to the first pilot port 79A as pilot oil, Conversely, when the volume of the inner chamber 64B of the second cylinder 60B becomes equal to or less than a certain level, the oil in the inner chamber 64A on the opposite side is guided to the second pilot port 79B as a pilot.

  More specifically, the partition wall 70 of the speed increaser 52 has a first pilot oil passage 88A and a second pilot oil passage 88B respectively communicating with the inner chambers 64A and 64B as shown in FIG. The first pilot oil passage 88A is connected to the first pilot port 79A of the introduction switching valve 78 via the first pilot line 90A, and the second pilot oil passage 88B is connected to the second pilot oil passage 88B. The pilot line 90B is connected to the second pilot port 79B of the introduction switching valve 78.

  Further, the partition wall 70 is provided with a first on-off valve 92A and a second on-off valve 92B for opening and closing the pilot oil passages 88A and 88B, respectively.

  As shown in FIG. 5, the pilot oil passages 88A and 88B include a spring accommodating chamber 88a that communicates with the inner chambers 64B and 64A, and an inner chamber that is smaller in diameter than the spring accommodating chamber 88a and opposite to the chamber 88a. The intermediate passage 88b is extended to 64A and 64B, and the outlet oil passage 88c extends radially outward from the intermediate passage 88b to the outer peripheral surface of the speed increaser 52.

  On the other hand, each of the on-off valves 92A and 92B has a valve body 92a accommodated in the spring accommodating chamber 88a and a shaft portion 92b extending from the valve body 92a along the intermediate oil passage 88b. The portion 92b further penetrates the intermediate oil passage 88b and protrudes into the opposite inner chambers 64A and 64B. The valve body 92a is smaller in diameter than the spring accommodating chamber 88a and larger in diameter than the intermediate oil passage 88b, and a peripheral portion of the valve body 92a is a step between the spring accommodating chamber 88a and the intermediate oil passage 88b. The pilot oil passages 88A and 88B are closed by contacting the part. That is, the on-off valves 92A and 92B are closed.

  The opening of the spring accommodating chamber 88a is closed by a lid 94 through which an oil passage hole for securing an oil passage passes, and a coil spring 96 is press-fitted between the lid 94 and the valve body 92a. A state in which the valve body 92a of each of the on-off valves 92A and 92B is pressed against the stepped portion by the elastic force of the coil spring 96, and the shaft portion 92b projects into the inner chambers 64A and 64B by a predetermined dimension. It is kept. Then, when the first piston 62A (second piston 62B) moves to a position where the volume of the inner chamber 64A (64B) is not more than a certain level, the piston 62A (62B) is connected to the on-off valve 92A (92B). When the on-off valve 92A (92B) is pressed against the urging force of the urging spring 96, the on-off valve 92A (92B) is opened to abut the pilot oil passage. The dimensions of the on-off valves 92A and 92B and the specifications of the coil spring 96 are set so as to open 88A (88B).

  As shown in FIG. 3, a shuttle valve 100 is provided in the middle of the supply oil passage 56, and the upstream side of the shuttle valve 100 branches to branch oil passages 56a and 56b to reach the outer ports 74A and 74B, respectively. . That is, the upstream ends of the branch oil passages 56a and 56b are connected to the outer ports 74A and 74B, respectively, and the downstream ends are connected to the inlet port of the shuttle valve 100, and the outlet port of the shuttle valve 100 is connected to the outlet port. A downstream portion of the supply oil passage 56 is connected. The bypass oil passage 80 joins the downstream side portion, and a check valve 102 is provided on the upstream side of the bypass oil passage 80.

  Further, the return oil passage 86 is connected to the branch oil passages 56a and 56b via regenerated oil passages 98A and 98B, respectively, and a reverse flow toward the return oil passage 86 is caused in each of the regenerated oil passages 98A and 98B. A check valve 99 is provided to prevent it.

  A direction switching valve 104 is provided between the joining position and the hydraulic cylinders 40A and 40B. The direction switching valve 104 is a three-position manual switching valve in the illustrated example, and is switched to a neutral position 104a, a first supply position 104b, and a second supply position 104c. Here, the neutral position 104a is a position where both the supply oil path 56 and the return oil path 58 are blocked, and the first supply position 104b is a position where the supply oil path 56 is connected to the hydraulic cylinders 40A and 40B. The second supply position 104c connects the supply oil path 56 to the hydraulic cylinders 40A, 40B. The second supply position 104c is connected to the cylinder side chamber 46 and the rod side chamber 45 of the cylinders 40A, 40B is connected to the return oil path 58. The rod side chamber 45 is connected to the head side chamber 46 of the cylinders 40A, 40B to the return oil path 58.

  Next, specific actions of the hydraulic drive device and the crusher 16 will be described.

  In this description, a state satisfying the following 1) to 4) is assumed as an initial state.

  1) As indicated by the solid lines in FIGS. 1 and 2, both the crushing arms 28A and 28B of the crusher 16 are in the open position. That is, both hydraulic cylinders 40A and 40B are contracted.

  2) The crusher 16 is transferred to a position where an object to be crushed is interposed between the crushing arms 28A, 28B of the crusher 16.

  3) The direction switching valve 104 shown in FIG. 3 is switched to the neutral position 104a.

  4) The pistons 62A and 62B exist at positions where the volume of the inner chamber 64A of the speed increaser 52 is smaller than the volume of the inner chamber 64B.

When the supply switching valve 104 is switched to the first supply position 104b from this state, the bypass switching valve 76 maintains the normal position 76a while the discharge pressure of the hydraulic pump 50 is low. The discharged oil flows into the introduction switching valve 78 through the bypass switching valve 76.

  At this time, the introduction switching valve 78 is in the first introduction position 78a, and the discharged oil is introduced into the inner chamber 64A from the inner port 72A on the first cylinder 60A side of the speed increaser 52 through the introduction switching valve 78. Is done. Accordingly, the first piston 62A, the connecting rod 68 connected to the first piston 62A, and the second piston 62B move together in the direction in which the volume of the inner chamber 64A increases (leftward in FIGS. 3 and 4). Then, the oil in the outer chamber 66A of the first cylinder 60A is pushed out from the outer port 74A.

  The pushed oil reaches the direction switching valve 104 via the shuttle valve 100 and the check valve 102, and is introduced from the direction switching valve 104 into the head side chamber 46 of the hydraulic cylinders 40A and 40B. The hydraulic cylinders 40A and 40B are extended by this hydraulic pressure supply, and both crushing arms 28A and 28B are operated in the closing direction. At this time, the hydraulic oil pushed out from each rod side chamber 45 returns to the tank through the return oil path 58. The oil pushed out from the inner chamber 64B on the second cylinder 62B side of the speed increaser 52 is sent from the inner port 72B to the branch oil passages 56a and 56b through the introduction switching valve 78 and the regeneration oil passages 98A and 98B. , Applied to the outer chamber 66B or the hydraulic cylinders 40A and 40B.

  Here, the flow rate of the hydraulic oil supplied into the hydraulic cylinders 40A and 40B, that is, the flow rate of the oil pushed out from the outer chamber 66A is larger than the flow rate of the discharge oil flowing into the inner chamber 64A. The area difference between 64A and the outer chamber 66A is increased. Accordingly, the drive of the hydraulic cylinders 40A and 40B is accelerated by the increase in the flow rate, and both the crushing arms 28A and 28B are quickly closed and operated.

  Here, when the volumes of both the cylinders 60A and 60B of the speed increaser 52 are smaller than the volumes of the hydraulic cylinders 40A and 40B, the inner chamber 64A and the inner chamber 64A are connected before the stroke of the hydraulic cylinders 40A and 40B is completed. Although the volume of the inner chamber 64B on the opposite side reaches a minimum, the second piston 62B that moves in a direction to reduce the volume of the inner chamber 64B is the shaft of the second on-off valve 92B shown in FIG. When the valve 92B is pushed against the elastic force of the coil spring 96 in contact with the end of the portion 92b, the valve 92B opens and opens the second pilot oil passage 88B. The oil in the inner chamber 64A is introduced into the second pilot port 79B of the introduction switching valve 78 through the second pilot oil passage 88B and the second pilot line 90B. It switched to the introduction position 78b.

  By this switching, the oil that has been introduced into the inner chamber 64A until then is introduced into the inner chamber 64B, and the operating directions of the pistons 62A and 62B and the connecting rod 68 are reversed in accordance with this switching. . That is, the pistons 62A and 62B move in such a direction that the volume of the inner chamber 64B increases and the volume of the inner chamber 64A decreases, and the oil in the outer chamber 66A that has reached the maximum volume is pushed out. .

  Thereafter, by the same action as described above, when the volume of the inner chamber 64A becomes equal to or less than a certain value, the first on-off valve 92A is opened, the first pilot oil passage 88A is opened, and the inner chamber 64B is opened. The oil inside is introduced into the first pilot port 79A of the introduction switching valve 78 through the first pilot line 90A, whereby the introduction switching valve 78 is again switched to the first introduction position 78a. By repeating the position switching of the introduction switching valve 78 and the reciprocating motion of the pistons 62A and 62B, the speed increasing operation can be continuously performed even when the volumes of the cylinders 60A and 60B are small. .

When the closing drive accompanied by the speed increase as described above proceeds and the crushing blades 27 of the crushing arms 28A, 28B come into contact with the object to be crushed, the driving loads of the hydraulic cylinders 40A, 40B and the driving loads of the hydraulic cylinders 40A, 40B are started. The discharge pressure of the hydraulic pump 50 increases rapidly. When the discharge pressure exceeds the set pressure of the variable relief valve 84 with a check valve attached to the bypass switching valve 76, the valve 84 is opened, and the discharge pressure becomes the pilot port of the bypass switching valve 76. The bypass switching valve 76 is switched to the bypass position 76b. From this point, the discharged oil is directly introduced into the hydraulic cylinders 40A and 40B through the bypass oil passage 80 that bypasses the speed increaser 52. Accordingly, although the speed increasing action disappears, the hydraulic pressure supplied to the hydraulic cylinders 40A and 40B increases accordingly, and the crushing arms 28A and 28B are driven in the closing direction with a force sufficient to crush the object to be crushed. The

  After the crushing operation is completed, when the direction switching valve 104 is switched from the first supply position 104b to the second supply position 104c, the oil discharged from the hydraulic pump 50 is discharged from the rods of the hydraulic cylinders 40A and 40B. The fluid flows into the side chamber 45 and is operated in a direction in which the hydraulic cylinders 40A and 40B are contracted. Due to this contraction, the crushing arms 28A and 28B are driven in the opening direction. Moreover, since the driving load in the opening direction is low, the bypass switching valve 76 is maintained at the normal position 76a, and hydraulic pressure is supplied via the speed increaser 52. Accordingly, the opening drive of both the crushing arms 28A and 28B is performed quickly, and the work efficiency is increased accordingly.

  However, even in the operation in the opening direction, when the driving load increases for some reason during the operation, the bypass switching valve 76 is switched to the bypass position 76b side, thereby driving with more emphasis on driving force than acceleration. It will be switched to the state.

  Although this reference embodiment includes a speed increaser 52, as shown in FIGS. 6 and 7 as an embodiment of the present invention, a pressure increaser 53 is provided on the same principle as the speed increaser 52. By constructing and introducing into the hydraulic circuit instead of the speed increaser 52, it is possible to construct a pressure increasing circuit.

  The booster 53 shown in the figure is exactly the same as the booster 52, and includes a first cylinder 60A and a second cylinder 60B sandwiching the partition wall 70, a first piston 62A and a second piston 62B, and both pistons 62A. , 62B, and the cylinders 60A, 60B are divided into inner chambers 64A, 64B and outer chambers 66A, 66B by the pistons 62A, 62B. And it has inner ports 72A and 72B communicating with the inner chambers 64A and 64B and outer ports 74A and 74B communicating with the outer chambers 66A and 66B.

  The booster 53 is different from the booster 52 according to the reference embodiment in the following two points.

1) Supply / Discharge Connection Out of the ports of the pressure intensifier 53, the outer ports 74A and 74B are connected to the introduction switching valve 78. Specifically, when the introduction switching valve 78 is switched to the first introduction position 78a, the outer port 74A is connected to the introduction oil passage 54 and the outer port 74B is connected to the return oil passage 86. Conversely, when the introduction switching valve 78 is switched to the second introduction position 78b, the outer port 74B is connected to the introduction oil passage 54 and the outer port 74A is connected to the return oil passage 86. So that the piping is.

  On the other hand, the inner ports 72A and 72B are connected to branch oil passages 56a and 56b of the supply oil passage 56, respectively.

2) Pilot oil passage As shown in FIG. 7, the first pilot oil passage 89A and the second pilot oil passage 89B provided in the pressure intensifier 53 are respectively closed with a lid 95 on the inner chambers 64B and 64A side. A spring housing chamber 89a, a small-diameter hole 89b having a smaller diameter than the spring housing chamber 89a and extending from the chamber 89a to the inner chambers 64B and 64A on the opposite side, and extending radially outward from the spring housing chamber 89a. And an outlet oil passage 89c reaching the outer peripheral surface of the vessel 52.

  On the other hand, in the first on-off valves 92A and 92B according to this embodiment, the valve bodies 92a are respectively housed in the spring accommodating chambers 89a, and the shaft portions 92b are inserted into the respective small diameter holes 89b with gaps therebetween. It protrudes into each inner chamber 64B, 64A. The valve body 92a is smaller in diameter than the spring accommodating chamber 89a and larger in diameter than the small-diameter hole 89b, and the elastic force of the coil spring 96 press-fitted between the valve body 92a and the lid 95 is used. The peripheral portion of the valve body 92a is held at a position where it contacts the step portion between the spring accommodating chamber 89a and the small diameter hole 89b to block the pilot oil passages 89A and 89B, respectively. In this state, the dimension of the shaft portion 92b is set so that the end portion of the shaft portion 92b projects into the inner chambers 64B and 64A by a predetermined dimension.

  In the embodiment according to the present invention, the bypass switching valve 76 and the bypass oil passage 80 shown in FIG. 3 are omitted.

  According to this apparatus, the continuous pressure increasing operation is performed on the same principle as the reference embodiment.

  Specifically, when the supply switching valve 104 shown in FIG. 3 is switched to the first supply position 104a from the initial state described above, the hydraulic pump 50 of the hydraulic pump 50 is passed through the introduction switching valve 78 at the first introduction position 78a. The discharged oil is introduced into the outer chamber 66A from the outer port 74A on the first cylinder 60A side of the speed increaser 53. Accordingly, the first piston 62A, the connecting rod 68 connected to the first piston 62A, and the second piston 62B are integrally moved so as to increase the volume of the outer chamber 66A (toward the right in FIGS. 6 and 7). Then, the oil in the inner chamber 64A of the first cylinder 60A is pushed out from the inner port 72A.

  The pushed oil reaches the direction switching valve 104 via the shuttle valve 100 and the check valve 102 in the same manner as the apparatus shown in FIG. 3, and the head side chambers of the hydraulic cylinders 40A and 40B from the direction switching valve 104. 46, the hydraulic cylinders 40A and 40B are extended. The pressure of the supplied hydraulic oil, that is, the flow rate of the oil pushed out from the inner chamber 64A is the difference in area between the inner chamber 64A and the outer chamber 66A compared to the pressure of the discharge oil flowing into the outer chamber 66A. Only getting bigger. Accordingly, the driving force of the hydraulic cylinders 40A and 40B increases by this pressure increase, and the crushing arms 28A and 28B are closed and driven with a larger driving force.

  Here, the first piston 62A interlocked with the second piston 62B moving in the direction of decreasing the volume of the outer chamber 66B comes into contact with the end portion of the shaft portion 92b of the second on-off valve 92B shown in FIG. When the valve 92B is pushed against the elastic force of the coil spring 96, the valve 92A is opened and the second pilot oil passage 89B is opened. Therefore, the second pilot oil passage 89B and the second pilot oil passage 89B are opened. The oil in the inner chamber 64A is introduced into the second pilot port 79B of the introduction switching valve 78 through the pilot line 90B, and the introduction switching valve 78 is switched to the second introduction position 78b.

As a result of this switching, the oil previously introduced into the outer chamber 66A is introduced into the outer chamber 66B, and the operating directions of the pistons 62A and 62B and the connecting rod 68 are reversed in accordance with the switching. . That is, the piston 62A, 62B is moved in the direction in which the volume of the outer chamber 66B is enlarged and the volume of the outer chamber 66A is reduced, and the inner chamber 6 having the maximum volume has been reached.
The oil in 4A will be pushed out.

  Thereafter, by the same operation as described above, when the volume of the outer chamber 66A becomes equal to or less than a certain value, the first on-off valve 92A is opened, the first pilot oil passage 88A is opened, and the inner chamber 64B is opened. The oil inside is introduced into the first pilot port 79A of the introduction switching valve 78 through the first pilot line 90A, whereby the introduction switching valve 78 is again switched to the first introduction position 78a. By repeatedly switching the position of the introduction switching valve 78 and the reciprocating motion of the pistons 62A and 62B, the pressure increasing operation can be continuously performed even when the volumes of the cylinders 60A and 60B are small. .

  This operation is the same when the direction switching valve 104 is switched to the second supply position 104c and the hydraulic cylinders 40A and 40B are driven to contract (that is, both the crushing arms 28A and 28B are driven in the opening direction). is there.

  The hydraulic circuit shown in FIGS. 3 to 7 may be one in which the speed increaser 52 or the pressure booster 53 is incorporated in the main body of the crusher 16, or the main body side of the working machine shown in FIG. For example, you may mount in the body 10 or an attachment support part (boom 12 or arm 14).

  In the former case, a normal hydraulic circuit is mounted on the main body side of the work machine, and the crusher 16 including the speed increaser 52 and the pressure booster 53 is attached to the tip of the arm 14. The speed increasing operation and the pressure increasing operation as described above can be performed, and the versatility on the main body side of the work machine can be improved.

  On the other hand, in the latter case, it is possible to perform drive control of a plurality of types of pinching devices attached to and detached from the tip of the arm 14 using a common hydraulic pump 50 and a speed increaser 52 or a pressure booster 53. become. Further, it is possible to use the speed increaser 52 and the pressure increaser 53 for speed increase drive and pressure increase drive of other hydraulic actuators (for example, a boom cylinder and an arm cylinder). Further, in this case, since the direction switching valve 104 can be provided in the supply section downstream of the speed increaser 52 and the pressure increaser 53 as shown in the figure, the speed increase is performed for the bidirectional driving of the hydraulic cylinders 40A and 40B. There is also an advantage that operation or pressure-increasing operation can be performed.

  In addition, the present invention can take the following embodiments.

  The present invention is not limited to the one having a plurality of hydraulic cylinders 40A and 40B, and can be applied to a hydraulic drive device in which a single hydraulic cylinder is interposed between the crushing arms 28A and 28B, for example. It is. The hydraulic cylinder is not limited to the hydraulic cylinder, and may include a hydraulic motor or other hydraulic actuator.

  When the pilot switching of the introduction switching valve 78 is performed using the oil in the speed increaser 52, the extraction location is not limited to the inner chambers 64A and 64B. For example, the oil in the outer chambers 66A and 66B is extracted. It may be. Further, the pilot oil passages 88A and 88B and the pilot oil passages 89A and 89B may be provided on the outer side so that the on-off valves 92A and 92B protrude toward the outer chamber side.

  The first cylinder 60A and the second cylinder 60B of the pressure intensifier 53 need only be arranged side by side in the axial direction, and do not necessarily have to be arranged at the coaxial position. That is, an offset may be given between the central axes of both cylinders 60A and 60B.

  The types of valves constituting the introduction switching valve 78, the supply switching valve 104, and the bypass switching valve 76 are not particularly limited. For example, an electromagnetic switching valve may be used as the introduction switching valve, and this introduction switching valve may be switched alternately between the first introduction position and the second introduction position periodically by electrical control.

  The application target of the hydraulic cylinder device according to the present invention is not limited to the crusher 16. For example, the present invention can also be applied to a press apparatus that moves a metal mold in a direction in which the molds are brought into contact with or separated from each other (that is, opens / closes) and presses a workpiece between the molds.

DESCRIPTION OF SYMBOLS 10 Airframe 12 Boom 14 Arm 16 Crusher 18 Arm connection part 20 Crusher main body 26 Support shaft 27 Crushing blade 28A Crushing arm 28B Crushing arm 40A Hydraulic cylinder 40B Hydraulic cylinder 50 Hydraulic pump 52 Booster 53 Booster 54 Introducing oil path 56 Supply oil path 58 Return oil path 60A 1st cylinder 60B 2nd cylinder 62A 1st piston 62B 2nd piston 64A 1st cylinder inner chamber 64B 2nd cylinder outer chamber 66A 1st cylinder outside Chamber 66B Outer chamber of second cylinder 68 Connecting rod 76 Bypass switching valve 78 Introduction switching valve 78a First introduction position 78b Second introduction position 79A First pilot port 79B Second pilot port 80 Bypass oil passage 86 Return Oil passage 88A First pilot oil passage 88B Second Pilot oil passage 89A First pilot oil passage 89B First pilot oil passage 90A First pilot line 90B Second pilot line 92A First on-off valve 92B second on-off valve 104 Supply switching valve

Claims (8)

A hydraulic drive device comprising a hydraulic actuator, a hydraulic pump, and a hydraulic circuit that connects the hydraulic pump to the hydraulic actuator to operate the hydraulic actuator,
The hydraulic circuit is
A pressure intensifier for increasing a ratio of the driving force of the hydraulic actuator to a discharge pressure of the hydraulic pump; an introduction portion for introducing discharge oil of the hydraulic pump into the pressure intensifier; and oil flowing out from the pressure intensifier A supply unit for supplying the actuator, and a return unit for returning the oil flowing out from the hydraulic actuator to the tank,
The pressure intensifier includes a first cylinder and a second cylinder that are aligned in the axial direction, and an inner chamber that is loaded in the first cylinder and is closer to the second cylinder in the first cylinder. A first piston that is partitioned into an outer chamber on the opposite side, an inner chamber that is loaded in the second cylinder and is closer to the first cylinder in the second cylinder, and an outer side on the opposite side A second piston that is partitioned into a chamber, the first piston and the second piston are connected to each other, and the pistons are linked to each other. A connecting member that is smaller than the cross-sectional area of
The introduction portion includes introduction switching means for alternately switching the introduction destination of the discharge oil of the hydraulic pump to the outer chamber of the first cylinder and the outer chamber of the second cylinder,
The supply unit includes an oil passage that guides oil flowing out from the inner chamber of the first cylinder and oil flowing out of the inner chamber of the second cylinder to the hydraulic actuator,
The introduction switching means includes a first introduction position for guiding the discharge oil of the hydraulic pump to the outer chamber of the first cylinder, and a second introduction for guiding the discharge oil of the hydraulic pump to the outer chamber of the second cylinder. And when the volume of the outer chamber of the first cylinder falls below a certain level, the position of the introduction switching valve is switched to the first introduction position, and the second hydraulic cylinder And a valve operating means for switching the position of the introduction switching valve to the second introduction position when the volume of the outer chamber becomes below a certain level. The hydraulic drive device according to claim 1, wherein
The introduction switching valve includes a first pilot portion to which a pilot pressure for switching the introduction switching valve to the first introduction position is input, and a pilot for switching the introduction switching valve to the second introduction position. A pilot switching valve having a second pilot section to which pressure is input,
The valve operating means guides oil in the first cylinder or the second cylinder to the first pilot section when the volume of the outer chamber of the first cylinder becomes a certain amount or less; and The oil in the second hydraulic cylinder or the oil in the first cylinder is guided to the second pilot section when the volume of the outer chamber of the second hydraulic cylinder becomes below a certain level. A hydraulic drive device characterized by that. The hydraulic drive device according to claim 2, wherein
The valve operating means includes a first pilot oil passage that communicates the first pilot portion with the first cylinder or the second cylinder, the second pilot portion, and the first cylinder. A second pilot oil passage communicating with the inside of the first cylinder or the second cylinder, and a position facing the inside of the first cylinder or the second cylinder and closing the first pilot oil passage. First, the first pilot oil passage is opened by receiving the pressure of the first piston or the second piston when the volume of the outer chamber of the first cylinder becomes a predetermined value or less. And an opening / closing valve of the second cylinder, a position facing the first cylinder or the second cylinder and closing the second pilot oil passage, and a volume of an outer chamber of the second cylinder Is constant Hydraulic drive system which comprises a second on-off valve to open said second pilot oil passage by receiving the pressing of the first piston or the second piston when it becomes the lower. In the hydraulic drive device according to any one of claims 1 to 3,
The hydraulic drive apparatus according to claim 1, wherein the supply unit includes a direction switching valve that switches a port of the hydraulic actuator that is a supply destination of oil flowing out from the speed increaser to switch an operation direction of the hydraulic actuator.   2. A first sandwiching member and a second sandwiching member that move relative to each other in an opening / closing direction, which is a direction in which they are brought into contact with each other, and sandwich a workpiece when moving in the closing direction, and for driving to open / close these sandwiching members. And a hydraulic drive device according to any one of 4 to 4, and when the hydraulic actuator of the hydraulic drive device is operated, at least one of the sandwiching members and the sandwiching member are moved relative to each other in the opening / closing direction. A pinching processing device characterized in that a hydraulic actuator of a hydraulic drive device is connected. The pinch processing apparatus according to claim 5, wherein
Each said pinching member is a crushing member which crushes the said processed material by pinching | interposing the said processed material between them, The pinching processing apparatus characterized by the above-mentioned. The pinch processing apparatus according to claim 6, wherein
An apparatus main body connected to each of the pinching members so as to be relatively movable in the opening and closing direction, and the apparatus main body is attached to the tip of the attachment support portion of a work machine including an attachment support portion whose tip is movable A pinching device having a mounting portion. The pinch processing device according to claim 7;
An attachment support portion having a mounted portion to which a mounting portion of the apparatus main body of the sandwich processing device is attached;
A machine body that supports the attachment support part so that the tip of the attachment support part can move;
A working machine, wherein a hydraulic circuit of the pinching device and a hydraulic pump connected to the hydraulic circuit are mounted on the machine body or the attachment support part.

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