JP2010242435A - Hydraulic device for crusher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a power loss in supplying pressure oil to a hydraulic cylinder and to improve the responsiveness of an opening/closing arm in a crusher including a crushing arm and the hydraulic cylinder for opening/closing the crushing arm. <P>SOLUTION: The crusher 2 is provided with an accumulator 22 accumulating oil discharged from heat side oil chambers 20AH, 20BH when the opening/closing cylinders 20A, 20B are contracted, while supplying the accumulated oil to the head side oil chambers 20AH, 20BH when the opening/closing cylinders 20A, 20B are elongated, and a pilot selector valve 23 switching oil supply/discharge between the accumulator 22 and the head side oil chambers 20AH, 20BH. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention belongs to the technical field of a hydraulic device for a crusher that is mounted as an attachment for crushing work on a main body of a work machine such as a dismantling work machine.

Generally, as an attachment for crushing work attached to the machine body of a work machine such as a dismantling work machine, an openable / closable crushing arm for crushing an object to be crushed, such as iron or concrete, and a hydraulic cylinder for opening / closing the crushing arm A crusher equipped is known. Such a crusher is generally attached to the tip of a long work arm supported by the machine body so that crushing work at a high place can be easily performed. Pressure oil is supplied to the cylinder from a hydraulic pump installed on the machine body side. For this reason, the hydraulic piping to the crusher is a long one that extends from the hydraulic pump on the machine body side to the crusher via the long work arm, and therefore due to the pressure loss of the piping There is a problem in that power loss is large, causing not only fuel consumption deterioration, but also the response of the crushing arm becomes slow, resulting in poor workability. In particular, when the hydraulic cylinder is extended to close the crushing arm, the amount of oil is about twice as large as when the hydraulic cylinder is reduced due to the difference in pressure receiving area between the head side and the rod side of the hydraulic cylinder. The above-mentioned problem becomes remarkable because it is necessary.
Therefore, conventionally, in order to speed up the closing operation of the crushing arm in a low load state where no object to be crushed is sandwiched, the oil discharged from the rod side oil chamber when the hydraulic cylinder is extended is supplied to the head side oil chamber. A technique provided with a fast valve is known (for example, refer to Patent Documents 1 and 2). In this case, pressure oil is supplied from the rod-side oil chamber of the hydraulic cylinder to the head-side oil chamber without passing through the long hydraulic pipe described above, which can contribute to reduction of pressure loss and from the speed increasing valve. The amount of pressure oil supplied to the head side oil chamber is increased, and the extension speed of the hydraulic cylinder can be increased.

JP 7-259139 A Japanese Patent Laid-Open No. 10-266587

  However, in Patent Documents 1 and 2, the amount of pressure oil supplied from the rod side oil chamber to the head side oil chamber via the speed increasing valve when the hydraulic cylinder is extended is the same as that of the head side of the hydraulic cylinder. Because of the difference in pressure receiving area from the rod side, it is about half of the total supply amount to the head side oil chamber, and the remaining half is supplied from the hydraulic pump. That is, even when pressure oil is supplied from the rod side oil chamber to the head side oil chamber via the speed increasing valve, about half of the total supply amount to the head side oil chamber is supplied from the hydraulic pump. However, the supply from the hydraulic pump is performed via the long pipe described above. Further, the operation of the speed increasing valve is only in a low load state where no object to be crushed is sandwiched, and in the high load state, the entire supply amount to the head side oil chamber is supplied from the hydraulic pump. For this reason, problems such as an increase in power loss due to the pressure loss of the above-mentioned piping and deterioration in workability due to a delay in response of the crushing arm cannot be eliminated, and the problem to be solved by the present invention is here. is there.

The present invention has been created in view of the above circumstances and has been created for the purpose of solving these problems. The invention of claim 1 is mounted as an attachment for crushing work on a machine body of a work machine, A crusher comprising a hydraulic cylinder supplied with pressure oil from a hydraulic pump installed in a main body, and a crushing arm that opens and closes based on a reduction and extension operation of the hydraulic cylinder. Sometimes the oil discharged from the head side oil chamber is accumulated, while the accumulator that supplies the accumulated oil to the head side oil chamber when the hydraulic cylinder is extended, and the oil supply / discharge between the accumulator and the head side oil chamber is switched. A crusher hydraulic apparatus comprising a switching valve.
According to a second aspect of the present invention, the switching valve is discharged from the head side oil chamber of the hydraulic cylinder by inputting the pressure of the pressure oil supplied from the hydraulic pump to the rod side oil chamber as the pilot pressure when the hydraulic cylinder is reduced. Is switched to the first position to supply the accumulated oil to the accumulator, while the pressure of the pressure oil supplied from the hydraulic pump to the head side oil chamber when the hydraulic cylinder is extended is input as a pilot pressure, The hydraulic device for a crusher according to claim 1, wherein the hydraulic device is a pilot switching valve that switches to a second position for supplying the oil to a head side oil chamber of the hydraulic cylinder.
The invention of claim 3 is characterized in that the crusher is provided with a regenerative valve for supplying oil discharged from the rod side oil chamber to the head side oil chamber when the hydraulic cylinder is extended. It is a hydraulic device of the crusher described.
According to a fourth aspect of the present invention, the pressure oil supplied from the hydraulic pump to the rod side oil chamber is supplied to the crusher when the pressure in the rod side oil chamber becomes equal to or higher than a preset rod side relief pressure when the hydraulic cylinder is reduced. The hydraulic device for a crusher according to any one of claims 1 to 3, further comprising a sequence valve that supplies the accumulator to the accumulator.
The invention of claim 5 is provided with a relief valve for relieving the supply pressure oil supplied to the accumulator when the pressure of the accumulator becomes equal to or higher than a preset accumulator relief pressure. 5. The hydraulic apparatus for a crusher according to claim 4, wherein the oil is flowed to the oil tank via a head side oil passage connected to a head side oil chamber of the hydraulic cylinder.

According to the first aspect of the present invention, when the hydraulic cylinder is extended, the supply pressure oil from the hydraulic pump and the pressure accumulation oil of the accumulator are merged and supplied to the head side oil chamber. In this case, the accumulator Since the pressure oil discharged from the head side oil chamber when the hydraulic cylinder is reduced is accumulated, most of the pressure oil supply required by the head side oil chamber is obtained only by the pressure oil supplied from the accumulator. As a result, the amount of pressure oil supplied from the hydraulic pump to the head side oil chamber when the hydraulic cylinder is extended can be greatly reduced, and the accumulator, the accumulator and the head side oil chamber, Since the crusher is equipped with a switching valve that switches between oil supply and discharge during the period, power loss due to pressure loss in the piping can be greatly reduced, contributing to improved fuel efficiency With wear, so that you can supply a large flow rate in a short time from the accumulator to the head side oil chamber, excellent responsiveness of the closing operation of the crushing arms, the workability is improved.
According to the second aspect of the present invention, it is possible to reliably switch the oil supply / discharge between the accumulator and the head side oil chamber when the opening / closing cylinder is reduced or extended.
According to the invention of claim 3, when the hydraulic cylinder is extended, the supply amount from the rod side oil chamber to the head side oil chamber by the regenerative valve and the pressure oil supply amount from the hydraulic pump to the head side oil chamber are further reduced. Can contribute to further improvement in fuel consumption and workability.
According to the invention of claim 4, when the pressure in the rod side oil chamber becomes equal to or higher than the rod side relief pressure when the hydraulic cylinder is reduced, the supply pressure oil from the hydraulic pump to the rod side oil chamber is supplied to the accumulator. Therefore, it is possible to accumulate pressure in the accumulator by effectively using the relief oil, and reliably prevent the accumulator pressure from being insufficient when the hydraulic cylinder is extended. Can do.
According to the invention of claim 5, the accumulator can be protected by the relief valve, and it is not necessary to separately provide an oil passage through which the relief oil flows to the oil tank, which can contribute to simplification of the circuit.

It is a general view of a demolition work machine. It is a figure which shows a crusher. It is a hydraulic circuit diagram of a crusher.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a demolition work machine equipped with a crusher 2 as an attachment for crushing work. The upper revolving body 4 is supported by the upper revolving body 4, and the upper end revolving body 4 is attached to and supported by the base end portion of the bendable working arm 5. In the present embodiment, the working arm 5 is supported by a boom 6 whose base end portion is supported by the upper swing body 4 so as to be swingable in the vertical direction, and by a tip portion of the boom 6 so as to be swingable in the vertical direction. The first arm 7 and the second arm 8 supported by the front end portion of the first arm 7 so as to be swingable in the vertical direction are configured, and are located on the most front end side of the working arm 5. The crusher 2 is swingably attached to the tip of the second arm 8. In the figure, reference numerals 9, 10, 11, and 12 denote a boom cylinder, a first arm cylinder, and a boom arm that extend and contract to swing the boom 6, the first arm 7, the second arm 8, and the crusher 2, respectively. The cylinder for the second arm and the cylinder for attachment.

  As shown in FIG. 2, the crusher 2 is attached to a front end portion of the work arm 5 (a front end portion of the second arm 8) so as to be swingable, and rotates to the mounting bracket 14 via a swivel bearing 15. A body 16 that can be freely attached, a turning motor 17 that rotates the body 16, a pair of crushing arms 19A and 19B that are supported by the body 16 via pin shafts 18A and 18B so as to be swingable open and close, the crushing arm 19A, A pair of open / close cylinders (corresponding to the hydraulic cylinders of the present invention) 20A and 20B that reduce and extend to open and close 19B, and a swivel joint 21 that connects hydraulic pipes so as to be rotatable relative to each other. In addition, the space 24 in the body 16 includes an accumulator 22 and a pilot switching valve (to be described later). This is) 23 is installed. The direction of the crushing arms 19A and 19B relative to the work arm 5 can be adjusted by driving the turning motor 17 and rotating the body 16, and the opening and closing cylinders 20A and 20B are adjusted. When the crushing arms 19A and 19B are opened and closed by reducing and extending, iron, concrete, and the like can be crushed by the crushing arms 19A and 19B.

  Next, the hydraulic device of the crusher 2 will be described based on the hydraulic circuit diagram of FIG. In FIG. 3, A is a circuit of a part installed in the machine body (upper swing body 3). The circuit A includes a hydraulic pump 25 driven by the engine E, an oil tank 26, and a crusher rotating operation. A crusher turning control valve 27 for controlling oil supply / discharge to the turning motor 17 based on the operation of a tool (not shown), and an opening / closing cylinder 20A based on the operation of a crushing arm operation tool (not shown). , A crushing arm control valve 28, which will be described later, is provided for performing oil supply / discharge control to 20B.

  On the other hand, B is a circuit of a part installed in the crusher 6, and the circuit B includes the turning motor 17, opening / closing cylinders 20A and 20B, swivel joint 21, accumulator 22, pilot switching valve 23, which will be described later. A sequence valve 35, a relief valve 37, a regenerative oil passage pilot check valve 40, and the like are provided. The opening / closing cylinders 20A, 20B are reduced by oil supply to the rod side oil chambers 20AR, 20BR and oil discharge from the head side oil chambers 20AH, 20BH to open the crushing arms 19A, 19B. The crushing arms 19A and 19B are configured to extend by supplying oil to the oil chambers 20AH and 20BH and discharging oil from the rod-side oil chambers 20AR and 20BR.

  Here, the crushing arm control valve 28 is a three-position switching valve that is switched based on the operation of the crushing arm operation tool, and is connected to the pump port 28P connected to the hydraulic pump 25 and the oil tank 26. A tank port 28T, and a rod side port 28R and a head side port 28H connected to a rod side oil passage 29 and a head side oil passage 30, which will be described later, via a swivel joint 21, respectively. The crushing arm control valve 28 closes the ports 28P, 28T, 28R, and 28H and supplies and discharges oil to and from the opening and closing cylinders 20A and 20B when the crushing arm operation tool is not operated. Although it is located in the neutral position N that is not performed, the pressure oil of the hydraulic pump 25 is supplied to the rod side oil passage 29 based on the operation of the crushing arm operation tool to the open side, while the head side oil passage The pressure oil of the hydraulic pump 25 is transferred to the head-side oil passage 30 based on the fact that the crushing arm operating tool is operated to the closing side. On the other hand, it is configured to switch to the extension side position Y where the oil in the rod side oil passage 29 is discharged to the oil tank 26.

  The rod-side oil passage 29 is an oil passage that connects the swivel joint 21 and the rod-side oil chambers 20AR and 20BR to supply and discharge oil to and from the rod-side oil chambers 20AR and 20BR of the opening and closing cylinders 20A and 20B. The head-side oil passage 30 is an oil passage that connects the swivel joint 21 and the head-side oil chambers 20AH and 20BH to supply and discharge oil to and from the head-side oil chambers 20AH and 20BH of the opening and closing cylinders 20A and 20B. .

  Further, 31 is a rod-side oil passage pilot check valve disposed in the rod-side oil passage 29. The pilot port 31a of the rod-side oil passage pilot check valve 31 receives the pilot pressure of the head-side oil passage 30 as a pilot. It is designed to be input as pressure. The rod side oil passage pilot check valve 31 is in a state where no pressure oil is supplied from the hydraulic pump 25 to the head side oil passage 30 and no pilot pressure is input to the pilot port 31a. Is allowed to flow to the rod side oil chambers 20AR and 20BR of the opening and closing cylinders 20A and 20B, while the flow from the rod side oil chambers 20AR and 20BR to the crushing arm control valve 28 is blocked. However, when pressure oil is supplied from the hydraulic pump 25 to the head-side oil passage 30 and pilot pressure is input to the pilot port 31a, the pressure between the rod-side oil chambers 20AR, 20BR and the crushing arm control valve 28 is increased. It is configured to be in an open state that allows bidirectional flow. Thus, the non-returned rod-side oil passage pilot check valve 31 can prevent oil from flowing out from the rod-side oil chambers 20AR and 20BR when the open / close cylinders 20A and 20B are stopped. When the opening and closing cylinders 20A and 20B are reduced, the flow of oil from the crushing arm control valve 28 to the rod side oil chambers 20AR and 20BR is allowed. When the pilot check valve 31 is in the open state, oil is allowed to be discharged from the rod side oil chambers 20AR, 20BR to the crushing arm control valve 28.

  Reference numeral 32 denotes a head-side oil passage check valve disposed in the head-side oil passage 30. The head-side check valve 32 is connected to the head-side oil chamber 20AH of the open / close cylinders 20A, 20B from the crushing arm control valve 28. The oil flow to 20BH is allowed, but the flow from the head side oil chambers 20AH and 20BH to the crushing arm control valve 28 is blocked.

  On the other hand, the accumulator 22 and the pilot switching valve 23 are installed in the space 24 in the body 16 of the crusher 2 as described above, but the accumulator 22 is used for switching the pilot switching valve 23 as described later. Based on this, the oil discharged from the head side oil chambers 20AH and 20BH is accumulated when the opening and closing cylinders 20A and 20B are contracted, while the accumulated oil is used as the head side oil chambers 20AH and 20BH when the opening and closing cylinders 20A and 20B are extended. It is comprised so that it may supply.

  That is, the pilot switching valve 23 is a three-position switching valve having first to third ports 23a to 23c and first and second pilot ports 23d and 23e, and the first port 23a is the head side oil. The second port 23b is connected to the downstream side (head side oil chambers 20AH and 20BH side) of the head side oil passage check valve 32. The second port 23b is connected to the head side oil passage 30 upstream of the passage check valve 32 (swivel joint 21 side). The head side oil passage 30 is connected, the third port 23c is connected to the accumulator oil passage 33, and the pressure of the rod side oil passage 29 is inputted to the first pilot port 23d as a pilot pressure, so that the second pilot The pressure of the head side oil passage 30 is input to the port 23e as a pilot pressure. The accumulator oil passage 33 is an oil passage connected to the accumulator 22 for supplying and discharging oil to and from the accumulator 22.

  The pilot switching valve 23 is not supplied with pressure oil from the hydraulic pump 25 to either the rod-side oil passage 29 or the head-side oil passage 30, and pilots are supplied to the first and second pilot ports 23d and 23e. In a state where no pressure is input, it is located at a neutral position N where oil is not supplied to or discharged from the accumulator 22. On the other hand, when pressure oil is supplied from the hydraulic pump 25 to the rod-side oil passage 29, the pressure in the rod-side oil passage 29 is input to the first pilot port 23d, and is discharged from the head-side oil chambers 20AH and 20BH. When the oil is switched to the first position X where oil is supplied to the accumulator 22, and pressure oil is supplied from the hydraulic pump 25 to the head side oil passage 30, the pressure of the head side oil passage 30 is supplied to the second pilot port 23e. By being input, the pressure accumulation oil in the accumulator 22 is switched to the second position Y that supplies the head side oil chambers 20AH and 20BH. Note that check valves 23f and 23g are arranged in the passages of the pilot switching valve 23 at the first position X and the second position Y, respectively, so that backflow is prevented.

  Further, reference numeral 34 denotes an accumulator replenishing oil passage for connecting the rod side oil passage 29 and the accumulator oil passage 33. The accumulator replenishing oil passage 34 has opening / closing cylinders 20A and 20B that reach the reduction side end and are connected to the rod side. A sequence valve 35 is provided that opens the accumulator refilling oil passage 34 when the pressure in the oil chambers 20AR and 20BR becomes equal to or higher than a preset rod-side relief pressure. When the accumulator replenishment circuit 34 is opened by the sequence valve 35, the pressure oil in the rod side oil passage 29 flows to the accumulator 22, and thus the opening / closing cylinders 20A and 20B are moved to the reduction side end. The pressure oil supplied from the hydraulic pump 25 to the rod-side oil chambers 20AR, 20BR after the pressure in the rod-side oil chambers 20AR, 20BR reaches or exceeds the rod-side relief pressure reaches the accumulator 22 via the sequence valve 35. It is designed to accumulate pressure.

  Reference numeral 36 denotes an accumulator relief oil passage that connects the accumulator oil passage 33 and the head side oil passage 30 downstream of the head side oil passage check valve 32. The accumulator relief oil passage 36 includes A relief valve 37 that causes pressure oil to flow from the accumulator oil passage 33 to the head side oil passage 30 when the pressure exceeds a preset accumulator relief pressure, and an oil flow from the accumulator oil passage 33 to the head side oil passage 30 There is a relief oil passage check valve 38 that allows flow but prevents reverse flow. Thus, the pressure oil supplied to the accumulator 22 after the pressure of the accumulator 22 rises to the accumulator relief pressure is relieved to the head side oil passage 30 via the relief valve 37 and the relief oil passage check valve 38. It is like that. The accumulator relief pressure is set to be higher than the rod side relief pressure.

  On the other hand, 39 is a reclaimed oil passage that connects the rod side oil chambers 20AR, 20BR of the opening / closing cylinders 20A, 20B and the head side oil chambers 20AH, 20BH. A valve (corresponding to the regenerative valve of the present invention) 40 is provided. The pressure of the rod side oil passage 29 is input to the pilot port 40a of the regenerative oil passage pilot check valve 40 as a pilot pressure, and the pilot pressure is not input to the pilot port 40a. Then, the flow of oil from the rod side oil chambers 20AR, 20BR to the head side oil chambers 20AH, 20BH is allowed, while the flow from the head side oil chambers 20AH, 20BH to the rod side oil chambers 20AR, 20BR is blocked. Although it is in a state, when a pilot pressure is input to the pilot port 40a, a closed state in which a bidirectional flow between the rod side oil chambers 20AR, 20BR and the head side oil chambers 20AH, 20BH is blocked is achieved. It is configured as follows. Thus, when the opening / closing cylinders 20A and 20B are extended, the regenerative oil passage pilot check valve 40 in the non-return state allows oil flow from the rod side oil chambers 20AR and 20BR to the head side oil chambers 20AH and 20BH. On the other hand, when the open / close cylinders 20A and 20B are stopped and contracted, the regenerative oil passage pilot check valve 40 is closed, so that the rod-side oil chambers 20AR and 20BR and the head-side oil chambers 20AH and 20BH are closed. The two-way oil flow between them is blocked.

  Next, oil supply and discharge when the open / close cylinders 20A and 20B are stopped and expanded and contracted will be described. First, when the crushing arm operating tool is not operated, as described above, the crushing arm control valve 28 is located at the neutral position N where oil supply / discharge to the open / close cylinders 20A and 20B is not performed. The opening / closing cylinders 20A and 20B are stopped. In this state, no pressure oil is supplied to the rod-side oil passage 29 and the head-side oil passage 30, so the pilot switching valve 23 is located at a neutral position N where oil supply / discharge to the accumulator 22 is not performed. The rod-side oil passage pilot check valve 31 is in a non-return state in which oil flow from the rod-side oil chambers 20AR, 20BR to the crushing arm control valve 28 is blocked, and the regenerated oil passage pilot check valve Reference numeral 40 denotes a closed state that prevents a bidirectional flow between the rod side oil chambers 20AR and 20BR and the head side oil chambers 20AH and 20BH, so that when the open / close cylinders 20A and 20B are stopped, It is possible to prevent the oil from flowing out from the oil chambers 20AR and 20BR and the opening and closing cylinders 20A and 20B from extending.

  On the other hand, when the opening / closing cylinders 20A and 20B are extended, that is, when the crushing arm operating tool is operated to close the crushing arms 19A and 19B, the crushing arm control valve 28 is moved to the extension side position Y. By switching, the pressure oil of the hydraulic pump 25 is supplied to the head side oil passage 30. The pressure oil of the hydraulic pump 25 supplied to the head side oil passage 30 is supplied to the head side oil chambers 20AH and 20BH of the open / close cylinders 20A and 20B via the head side oil passage check valve 32. Further, at this time, when the pressure of the head side oil passage 30 is input to the second pilot port 23e of the pilot switching valve 23, the pilot switching valve 23 is switched to the second position Y, and the pressure accumulation oil of the accumulator 22 is changed to the head side. The oil chambers 20AH and 20BH are supplied. In addition, the regenerative oil passage pilot check valve 40 is in a non-return state allowing oil flow from the rod side oil chambers 20AR, 20BR to the head side oil chambers 20AH, 20BH. While the pressure is higher than the head side oil chambers 20AH and 20BH, the oil discharged from the rod side oil chambers 20AR and 20BR is supplied to the head side oil chambers 20AH and 20BH as recycled oil. On the other hand, the rod-side oil passage pilot check valve 31 is in an open state that allows bidirectional flow between the rod-side oil chambers 20AR, 20BR and the crushing arm control valve 28. Exhaust oil from the oil chambers 20AR, 20BR is removed via the rod-side oil passage pilot check valve 31 and the crushing arm control valve 28 at the extension side position Y, except for the supply to the oil chambers 20AH, 20BH. It is discharged to the oil tank 26.

  That is, when the opening and closing cylinders 20A and 20B are extended, the head side oil chambers 20AH and 20BH are supplied with pressure oil supplied from the hydraulic pump 25, pressure oil supplied from the accumulator 22, and rod side oil chambers 20AR, The regenerated oil from 20BR is joined and supplied. In this case, the accumulator 22 is discharged from the head side oil chambers 20AH and 20BH when the opening and closing cylinders 20A and 20B are reduced, as will be described later. Since almost the entire amount of oil is stored, only the supply pressure oil from the accumulator 22 can supply most of the supply amount required by the head side oil chambers 20AH and 20BH during expansion. Moreover, since the regenerated oil from the rod side oil chambers 20AR and 20BR is also supplied, the hydraulic oil pump 25 to the head side oil chamber 2 AH, it can greatly reduce the supply to 20BH.

  On the other hand, when the opening / closing cylinders 20A and 20B are reduced, that is, when the crushing arm operation tool is operated to open to open the crushing arms 19A and 19B, the crushing arm control valve 28 is moved to the reduction side position X. By switching, the pressure oil of the hydraulic pump 25 is supplied to the rod side oil passage 29. The pressure oil of the hydraulic pump 25 supplied to the rod-side oil passage 29 is supplied to the rod-side oil chambers 20AR and 20BR of the open / close cylinders 20A and 20B via the non-returned rod-side oil passage pilot check valve 31. Is done. At this time, the regenerative oil passage pilot check valve 40 is in a closed state that prevents the flow of oil from the rod side oil chambers 20AR, 20BR to the head side oil chambers 20AH, 20BH, and to the rod side oil chambers 20AR, 20BR. Is prevented from flowing into the head side oil chambers 20AH and 20BH. Further, at this time, when the pressure in the rod side oil passage 29 is input to the first pilot port 23d of the pilot switching valve 23, the pilot switching valve 23 is switched to the first position X, and from the head side oil chambers 20AH and 20BH. The discharged oil is accumulated in the accumulator 22. In this case, since the oil flow from the head side oil chambers 20AH and 20BH to the crushing arm control valve 28 is blocked by the head side oil passage check valve 32, the oil discharged from the head side oil chambers 20AH and 20BH Substantially the entire amount is accumulated in the accumulator 22.

  Further, when the opening / closing cylinders 20A, 20B are contracted, if the opening / closing cylinders 20A, 20B reach the contracting end and the pressure in the rod-side oil chambers 20AR, 20BR exceeds the rod-side relief pressure, the accumulator replenishment circuit 34 The arranged sequence valve 35 is opened, and the pressure oil of the hydraulic pump 25 supplied to the rod side oil passage 29 is automatically accumulated in the accumulator 22. Further, when the pressure of the accumulator 22 becomes equal to or higher than the accumulator relief pressure, the relief valve 37 disposed in the accumulator relief oil passage 36 is opened, and the pressure oil supplied to the accumulator 22 is relieved to the head side oil passage 30, and the head side oil The oil is discharged from the passage 30 to the oil tank 26 via the crushing arm control valve 28 at the reduction position X.

  In the present embodiment configured as described, pressure oil is supplied to the machine body of the dismantling machine 1 as a crushing attachment for crushing iron, concrete, or the like from a hydraulic pump 25 installed in the machine body. A crusher 2 equipped with opening and closing cylinders 20A and 20B and crushing arms 19A and 19B that open and close based on the reduction and extension operations of the opening and closing cylinders 20A and 20B is mounted. Stores the oil discharged from the head side oil chambers 20AH and 20BH when the opening and closing cylinders 20A and 20B are reduced, while the accumulated oil is stored in the head side oil chambers 20AH and 20BH when the opening and closing cylinders 20A and 20B are extended. Pilot switching for switching the accumulator 22 to be supplied and the oil supply / discharge between the accumulator 22 and the head side oil chambers 20AH and 20BH 23 and is provided.

  Thus, when the open / close cylinders 20A and 20B are extended, the supplied pressure oil from the hydraulic pump 25 and the accumulated oil in the accumulator 22 are supplied to the head side oil chambers 20AH and 20BH. However, in this case, since the pressure oil discharged from the head side oil chambers 20AH and 20BH when the opening and closing cylinders 20A and 20B are reduced is accumulated in the accumulator 22, only the pressure oil supplied from the accumulator 22 is accumulated. Thus, most of the pressure oil supply amount required by the head side oil chambers 20AH and 20BH can be supplied. As a result, the amount of pressure oil supplied from the hydraulic pump 25 to the head side oil chambers 20AH and 20BH when the open / close cylinders 20A and 20B are extended can be greatly reduced, and the pressure is applied to the head side oil chambers 20AH and 20BH. Since the accumulator 22 that supplies oil and the pilot switching valve 23 that switches oil supply and discharge between the accumulator 22 and the head side oil chambers 20AH and 20BH are provided in the crusher 2, power loss due to pressure loss of the piping is reduced. It is possible to greatly reduce the fuel consumption and contribute to improving the fuel consumption, and it is possible to supply a large flow rate from the accumulator 22 to the head side oil chambers 20AH and 20BH in a short time, and the responsiveness of the closing operation of the crushing arms 19A and 19B. Excellent workability.

  In addition, the pilot switching valve 23 receives the pressure oil pressure supplied from the hydraulic pump 25 to the rod side oil chambers 20AR and 20BR as the pilot pressure when the opening and closing cylinders 20A and 20B are reduced. Pressure oil supplied from the hydraulic pump 25 to the head side oil chambers 20AH and 20BH when the open / close cylinders 20A and 20B are extended is switched to the first position X where the oil discharged from the chambers 20AH and 20BH is supplied to the accumulator 22 Is input to the head side oil chambers 20AH and 20BH as the pilot pressure is switched to the second position Y, so that the opening and closing cylinders 20A and 20B are contracted and expanded. The oil supply and discharge between the accumulator 22 and the head side oil chambers 20AH and 20BH Nau Upon a signal for the recombinant 該切 it is not necessary to guide the crusher 2 from machine body side can be reliably performed in a simple structure.

  Further, the crusher 2 has a regenerated oil path pilot check valve 40 that supplies oil discharged from the rod side oil chambers 20AR and 20BR to the head side oil chambers 20AH and 20BH as reclaimed oil when the opening and closing cylinders 20A and 20B are extended. Since it is provided, in addition to the supply from the accumulator 22 described above, the supply from the regenerative oil passage pilot check valve 40 and the amount of pressure oil supplied from the hydraulic pump 25 to the head side oil chambers 20AH and 20BH are further reduced. This can contribute to further improvement in fuel consumption and workability.

  In addition, the crusher 2 has the hydraulic pump 25 to the rod-side oil chambers 20AR and 20BR when the pressure in the rod-side oil chambers 20AR and 20BR becomes equal to or higher than the rod-side relief pressure when the opening and closing cylinders 20A and 20B are reduced. Since the sequence valve 35 for supplying the supplied pressure oil to the accumulator 22 is provided, the relief oil in the rod side oil passage 29 can be effectively used to accumulate pressure in the accumulator 22, and thus open and close Therefore, it is possible to reliably prevent the accumulated oil in the accumulator 22 from being insufficient when the cylinders 20A and 20B are extended.

  Moreover, when the pressure of the accumulator 22 becomes equal to or higher than a preset accumulator relief pressure, the supply pressure oil to the accumulator 22 is relieved by the relief valve 37 and the oil relieved from the relief valve 37 is Since the oil is discharged to the oil tank 26 via the head-side oil passage 30, it is possible to protect the accumulator 22, and it is not necessary to separately provide an oil passage for supplying relief oil to the oil tank 26, thereby simplifying the circuit. Can contribute.

  INDUSTRIAL APPLICABILITY The present invention is used in a crusher that is mounted as an attachment for crushing work on a main body of a work machine such as a dismantling work machine, and is used for a hydraulic device that contracts and expands and contracts a hydraulic cylinder for opening and closing a crushing arm of the crusher. be able to.

DESCRIPTION OF SYMBOLS 1 Demolition work machine 2 Crusher 19A, 19B Crush arm 20A, 20B Open / close cylinder 20AH, 20BH Head side oil chamber 20AR, 20BR Rod side oil chamber 22 Accumulator 23 Pilot switching valve 25 Hydraulic pump 26 Oil tank 29 Rod side oil passage 30 Head side oil passage 35 Sequence valve 37 Relief valve 40 Regenerative oil passage pilot check valve

Claims (5)

A hydraulic cylinder mounted on the main body of the work machine as an attachment for crushing work and supplied with pressure oil from a hydraulic pump installed on the main body, and a crushing arm that opens and closes based on a contraction and extension operation of the hydraulic cylinder An accumulator for accumulating oil discharged from the head side oil chamber when the hydraulic cylinder is reduced, and supplying the accumulated oil to the head side oil chamber when the hydraulic cylinder is extended; A hydraulic apparatus for a crusher, comprising a switching valve for switching oil supply / discharge between an accumulator and a head side oil chamber. The switching valve supplies the oil discharged from the head side oil chamber of the hydraulic cylinder to the accumulator when the pressure of the pressure oil supplied from the hydraulic pump to the rod side oil chamber is input as a pilot pressure when the hydraulic cylinder is reduced. On the other hand, when the hydraulic cylinder is extended, the pressure oil pressure supplied from the hydraulic pump to the head side oil chamber is input as the pilot pressure, so that the accumulator accumulated oil is used as the hydraulic cylinder head side oil. The hydraulic device for a crusher according to claim 1, wherein the hydraulic device is a pilot switching valve that switches to a second position to be supplied to the chamber. The hydraulic device for a crusher according to claim 1 or 2, wherein the crusher is provided with a regeneration valve for supplying oil discharged from the rod side oil chamber to the head side oil chamber when the hydraulic cylinder is extended. . A sequence valve that supplies the accumulator with pressure oil supplied from the hydraulic pump to the rod-side oil chamber when the pressure in the rod-side oil chamber exceeds the preset rod-side relief pressure when the hydraulic cylinder is reduced. The hydraulic apparatus for a crusher according to any one of claims 1 to 3, wherein a crusher is provided. The crusher is provided with a relief valve that relieves the pressure oil supplied to the accumulator when the accumulator pressure exceeds a preset accumulator relief pressure, and the oil released from the relief valve is supplied to the hydraulic cylinder. The hydraulic apparatus for a crusher according to claim 4, wherein the hydraulic apparatus is configured to flow through an oil tank via a head-side oil passage connected to a head-side oil chamber.

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