JP2003232301A - Crusher and attachment for construction work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost by eliminating a hydraulic piping for revolution and to lighten mounting work in an automatic revolution type crusher to be mounted to an arm of a self-propelling work struck. <P>SOLUTION: A hydraulic motor for revolution is arranged inside a bracket or the like, branch pipes are branched respectively from the forward and backward hydraulic pipings to be connected to a hydraulic cylinder for opening/ closing the arm, and both branch pipes are connected with the hydraulic motor. A function to communicate with the hydraulic motor side when reached prescribed pressure or more is imparted to one branch pipe branched from a pipe passage to be the supply side during the arm opening action, and the function to prevent back-flow to the hydraulic motor 5 side is imparted to the other branch pipe branched from the pipe passage to be the supply side during the arm closing action. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attachment for a construction machine mounted on a self-propelled work cart. INDUSTRIAL APPLICABILITY The present invention is particularly suitable as a crusher mounted on a self-propelled work cart.

[0002]

2. Description of the Related Art A crusher is known as one of attachments attached to the tip of an arm of a self-propelled work cart such as a hydraulic excavator. The crusher has an opening / closing arm like a finger or a claw of a crab, and the opening / closing arm is opened and closed by using a hydraulic cylinder.

When a building is demolished by the above-mentioned crusher, it is necessary to adjust the position and posture of the crusher and the angle of the opening and closing direction of the crushing arm according to the object to be crushed. Therefore, it is necessary to rotate the open / close arm as a whole. Here, as means for rotating the opening / closing arm of the crusher, there are a method of pressing the opening / closing arm against other members to forcibly rotate, and a method of automatically rotating by an actuator such as a hydraulic motor.

As one of the crushers adopting the former method, the one disclosed in Japanese Patent Publication No. 7-103700 is known. The crusher disclosed in Japanese Examined Patent Publication No. 7-103700 has a structure in which the main body frame of the crusher is attached to an arm of a hydraulic excavator or the like via a slewing bearing. The disc brakes are used to give the crusher body frame turning resistance due to frictional forces.

The crusher adopting the former method is preferable because of its simple structure. In addition, the crusher adopting the former method, when an excessive twist acts on the crusher during the crushing work,
It is preferable because the crusher naturally turns to avoid destruction. However, the crusher adopting the former method has a drawback that it requires a considerable skill in operation.

Further, with the configuration of the prior art, it is difficult to properly adjust the tightening torque of the disc brake. That is, if the tightening torque of the disc brake is large, there is an advantage that there is little deviation due to inadvertent rotation due to contact with an obstacle or eccentricity of the center of gravity, but a large impact force is required when turning the opening and closing arm, There is a problem in that unnecessary shock is applied to the machine, causing damage and failure. On the other hand, if the tightening torque is small, the opening / closing arm will swivel due to a slight impact in the crushing work, and the angle will be apt to be deviated, and the operability will be deteriorated. Further, when the friction plate of the disc brake is worn, the braking force is significantly reduced, and frequent maintenance such as adjustment and replacement of the friction plate is required.

This adjustment and maintenance is a complicated work that requires experience and skill, and in order to maintain an appropriate braking force, it is necessary to repeat the fine adjustment and maintenance in a short period of time, which is very troublesome.

In the latter system, a hydraulic motor or the like is mounted on a part of the crusher, and the hydraulic motor and the main frame of the crusher are engaged with each other. In the prior art, independent hydraulic pipes are arranged along the arm of the hydraulic excavator for each of the hydraulic cylinder for opening and closing the arm and the hydraulic motor for turning. Each of the two lines of hydraulic pipe is connected at its tip end to a hydraulic connection provided on a mounting bracket of the crusher. Then, the crushing arm is opened / closed and rotated by a pedal or a lever installed in the cab. As described above, according to the latter method, since the opening / closing arm can be swung by the hydraulic operation, the workability is significantly improved, but the piping is complicated and a lot of hydraulic equipment is required.

That is, when the conventional crusher is mounted on a hydraulic excavator or the like, not only a hydraulic pipe for opening and closing an arm is provided in the hydraulic excavator, but also a control valve, an operation pedal, a lever, and a dedicated valve for the hydraulic motor for turning are provided. Modification work is required to install the hydraulic pipes. In the conventional crusher, as described above, it is necessary to separately install the two pipes for opening and closing the arm and the pipe for turning, so that the material cost and the labor cost are high. Further, depending on the model of the hydraulic motor, it may be necessary to additionally provide a dedicated drain pipe for returning the casing drain to the tank, which further increases material costs and labor costs.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems associated with the crusher capable of automatically turning, and the pressure of the hydraulic oil sent to the hydraulic cylinder for opening and closing the arm causes An object of the present invention is to provide a crusher including a hydraulic circuit that automatically rotates a turning hydraulic motor. Another object of the present invention is to provide a time margin and improve operability when the turning hydraulic motor is automatically turned. Another object of the present invention is to provide a hydraulic circuit in which a piping system dedicated to turning is omitted to reduce piping work costs, and in addition, a crusher can be attached to and detached from a hydraulic excavator in a short time.

Further, according to the present invention, when a shocking twist acts on the crusher during the crushing work, this twisting force is smoothly released,
One of the purposes is to prevent the destruction of the crusher. Further, the present invention is a technique that can be applied to a case where a method of forcibly turning by pressing the opening / closing arm against another member is adopted, without using a mechanical friction mechanism such as a disc brake,
It is intended to provide a braking mechanism which has excellent durability and reliability, is easy to maintain and adjust, and does not require frequent maintenance.

[0012]

In order to achieve the above object, the present invention installs a turning hydraulic motor in a crusher and branches the turning hydraulic motor from a piping system of a hydraulic cylinder for opening and closing an arm. The branch pipes are connected. When crushing work, the entire amount of hydraulic oil is supplied to the hydraulic cylinder for opening and closing the arm.When turning, the hydraulic oil is further supplied in the arm opening direction with the arm fully opened, and the hydraulic oil increases due to the pressure increase at that time. Is supplied to the turning hydraulic motor.

In the crusher according to the present invention, the turning hydraulic motor is arranged in the bracket or the like, and the branch pipes are branched from the reciprocating hydraulic pipes connected to the hydraulic cylinders for opening and closing the arms. Basically, when connecting both branch pipes to the hydraulic motor, the branch pipe that branches off from the pipeline that is the supply side when the arm is opened communicates with the hydraulic motor side when a certain pressure or more is reached. The other branch pipe branching from the pipe line on the supply side when the arm is closed is provided with the function of preventing backflow to the hydraulic motor side.

In the crusher according to the present invention, the branch pipes are branched from the reciprocating hydraulic pipes connected to the hydraulic cylinders for opening and closing the arms, and when both the branch pipes are connected to the hydraulic motor, they are supplied when the arm is opened. A branch valve with a relief function that communicates with the hydraulic motor side when a certain pressure or more is reached is provided in one branch pipe that branches from the pipeline that is the side, and it branches from the pipeline that is the supply side when the arm is closed. A check valve for preventing reverse flow to the hydraulic motor side is interposed in the other branch pipe.

The impact pressure bypass means is installed in the middle of both branch pipes from the throttle valve with relief function or the check valve to the hydraulic motor. As the impact pressure bypass means, it is preferable that two pipe lines are bypass-connected in parallel to both branch pipes, and adjustable relief valves are respectively provided in the bypass flow passages in opposite directions. Further, as such an impact pressure bypass means, two pipe lines are bypass-connected in parallel to both branch pipes,
Two opposed check valves may be interposed in the bypass passages in opposite directions, and the intermediate positions of the check valves in the bypass passages may be communicated with each other via the adjustable relief valve.

Further, it is possible to use a pilot switching valve and a resistance applying means as the impact pressure bypass means, and to connect the high pressure port of the hydraulic motor to the resistance applying means in response to the pressure of both ports of the hydraulic motor. Is.

It is also possible to provide the bypass flow passage with two sets of one-way resistance means which allow the flow in one direction and allow the flow in the other direction only when the pressure exceeds a predetermined pressure. Furthermore, a pilot switching valve, a relief valve and a check valve are used as impact pressure bypass means.The relief valve and the check valve are installed in the direction in which the check valve opens along the flow at the time of relief, and the pilot switching valve is used. A configuration in which the high-pressure port of the hydraulic motor automatically communicates with the inlet side of the relief valve is also possible.

In addition to the above circuit configuration, the hydraulic oil is sent to the turning hydraulic motor after a certain time has elapsed after the hydraulic oil was supplied to the downstream position of the throttle valve with the relief function of one branch pipe. Delay means may be installed. The delay means supplies hydraulic oil to the turning hydraulic motor after a slight delay after the crushing arm opening is fully opened. This delay means can also be realized by providing a fluid cavity downstream of the throttle valve with relief function. The delay means includes a switching valve having two positions of shutoff and passage, a communication passage connecting the inlet port of the switching valve with the pilot oil chamber, and a check valve from the pilot oil chamber to the upstream side of the throttle valve with a relief function. And a return passage for the pilot oil that communicates with each other. In this configuration, a spring is arranged on one end surface of the spool of the switching valve, and a pressing means having the pilot oil chamber is arranged on the other end surface thereof. When a certain amount or more of hydraulic oil is supplied to the pilot oil chamber, the spool is switched to the passing position.

That is, the concrete constitution of the present invention is that the crusher is equipped with a crushing arm which is mounted on an arm of a self-propelled work cart and is opened and closed by a hydraulic actuator for opening and closing, and a turning mechanism which is turned by a turning hydraulic motor. In, in the hydraulic flow path communicating with the hydraulic actuator for opening and closing, having a branch flow path branched from the side that is the hydraulic oil supply side when the crushing arm is opened or closed, Is
There is a closing / communication means that is normally closed and communicates when a predetermined pressure or more is reached, and a fluid cavity is provided on the downstream side of the closing / communication means, and the crushing arm is in the open or closed state for opening and closing. When the pressure applied to the hydraulic actuator reaches or exceeds a predetermined pressure, the closing / communication means communicates with each other, and the hydraulic oil preferentially flows into the fluid cavity, and then the hydraulic oil is supplied to the swing hydraulic motor to rotate the hydraulic motor. Is a crusher that operates.

A similar invention is a crusher equipped with a crushing arm which is mounted on an arm of a self-propelled work cart and is opened and closed by a hydraulic actuator for opening and closing, and a crushing machine which is provided with a turning mechanism which is turned by a hydraulic motor for turning. A hydraulic flow path that communicates with the hydraulic actuator for use, and has a branch flow path branched from the side that is the hydraulic oil supply side when the crushing arm is opened or closed, and the branch flow path is always Is closed and intervenes a closing / communication means which communicates when a predetermined pressure or more is reached, and a branch means is further provided with a delay means,
The crushing arm is in the open or closed state, the pressure applied to the opening / closing hydraulic actuator reaches a predetermined pressure or more, and after the delay time elapses, hydraulic oil is supplied to the turning hydraulic motor to operate the turning hydraulic motor. It is a crusher.

Further, a similar invention is a crusher equipped with a crushing arm which is mounted on an arm of a self-propelled work truck and is opened and closed by a hydraulic actuator for opening and closing, and a crushing machine which is provided with a turning mechanism which is turned by a hydraulic motor for turning. Supplying when the crushing arm is opened, with a reciprocating hydraulic flow path communicating with the hydraulic hydraulic actuator, and a branch flow path branched from each hydraulic flow path and connected to the turning hydraulic motor. In the branch flow path branched from the side part,
A closing / communication means and a delay means that are normally closed and communicate with each other when a predetermined pressure or more is reached are provided, and a backflow prevention means that blocks the flow of hydraulic oil to the turning hydraulic motor side is provided in the other branch flow path. It is a crusher characterized by being provided.

In the above-mentioned invention, the crushing arm is in the open state (or closed state) which is the hydraulic flow path of the opening / closing hydraulic actuator for opening / closing the crushing arm with respect to the turning hydraulic motor.
In this case, the hydraulic oil is supplied from the side that becomes the hydraulic oil supply side. When adopting a configuration in which the hydraulic oil is supplied from the side that becomes the hydraulic oil supply side when the crushing arm is opened, when the crushing arm is closed and the lump of concrete or the like is crushed, the turning hydraulic motor is Does not work. In addition, the branch passage that serves as the hydraulic oil supply passage has a closing / communicating means that is normally closed and communicates when a predetermined pressure or more is reached. However, the turning hydraulic motor does not operate. Further, since the branch flow passage is provided with the fluid cavity and the delay means, the turning hydraulic motor does not suddenly operate even when the pressure exceeds the predetermined pressure. Therefore, there is a time margin before the turning hydraulic motor starts to operate, and the turning hydraulic motor can be operated only when the operator intentionally operates the turning hydraulic motor.

To rotate the crushing arm using the crusher of the present invention, the crushing arm is opened (or closed) and the state is continued. As a result, the pressure in the branch passage reaches a predetermined pressure or higher, the closing / communication means is brought into the communication state, and after the delay time has elapsed, hydraulic oil is supplied to the turning hydraulic motor.

The closing / communication means can be constituted by a relief valve and a throttle valve.

It is desirable that the relief valve is capable of adjusting the working pressure.

It is recommended that the turning hydraulic motor be provided with impact pressure bypass means.

As the impact pressure bypass means, two ports for allowing hydraulic oil to flow in and out of the turning hydraulic motor are provided, and one or more bypass flow passages are provided between the ports, and the bypass flow passage is always provided. It is conceivable that the valve is closed and the high pressure side communicates with the low pressure side when one of both ports reaches a predetermined pressure or higher.

In addition, the turning hydraulic motor has two ports through which hydraulic oil flows in and out, two bypass flow passages are provided between the ports, and relief valves are mutually provided in both bypass flow passages. A sub bypass passage may be provided in which the sub bypass passage is interposed in the opposite direction, and the check valve is interposed in parallel with the relief valve.

Further, the turning hydraulic motor has two ports through which hydraulic oil flows in and out, and A and B are provided between the ports.
Two bypass flow passages are provided, two check valves are interposed in the A side bypass flow passage in a direction in which they communicate with each other inward, and two check valves are provided in the B side bypass flow passage. Are interposed in a direction in which they communicate with each other outwardly, and each bypass flow path A, B
A relief valve is provided at an intermediate portion between the check valves, and when the pressure between the check valves in the bypass passage on the A side becomes equal to or higher than a predetermined pressure, the relief valve opens to bypass the A side bypass. A configuration in which hydraulic oil flows from the flow passage to the bypass passage on the B side is also recommended.

The configuration of the bypass flow passage described above can also be applied to a crusher of the type having no delay means. That is, the invention of the crusher is a crusher equipped with a crushing arm that is mounted on an arm of a self-propelled work cart and that is opened and closed by a hydraulic actuator for opening and closing, and a slewing mechanism that is slewed by a hydraulic motor for slewing. The hydraulic flow path communicates with the hydraulic actuator, and has a branch flow path branched from the side that becomes the hydraulic oil supply side when the crushing arm is opened, and the branch flow path is normally closed. When the crushing arm is in the open state and the pressure applied to the opening / closing hydraulic actuator reaches the predetermined pressure or more, the turning hydraulic motor operates, and the closing / communication means that communicates when the predetermined pressure or more is reached. The turning hydraulic motor has two ports for the hydraulic oil to flow in and out, two bypass passages of A and B are provided between the ports, and two reverse passages are provided in the bypass passage on the A side. The valves are arranged so as to communicate inward with each other, and the two check valves are arranged in the bypass passage on the B side so as to communicate with each other outward, and the check valves for the bypass passages A and B are provided. A relief valve is provided at an intermediate portion between the two, and when the pressure between the check valves of the bypass passages on the A side becomes equal to or higher than a predetermined pressure, the relief valve opens and the bypass passage on the A side is moved to the B side. The hydraulic oil flows through the bypass passage on the side.

As the structure of the delay means, the closing / communication means is composed of a relief valve and a throttle valve, and the delay means is
A pilot switching valve having two positions of shutoff and communication and having a pilot chamber, a communication passage connecting the inlet port side of the pilot switching valve with the pilot chamber, and a reverse from the pilot chamber to the upstream side of the closing / communication means. The spool of the pilot switching valve is always urged to the shut-off position by the urging means, and the spool is opened when a certain amount or more of hydraulic oil is supplied to the pilot oil chamber. It is recommended to switch to the communication position.

The delay means may be a hydraulic cylinder connected in parallel with the turning hydraulic motor.

Here, it is important that the hydraulic cylinder operates at a pressure lower than that of the turning hydraulic motor.

Further, the invention focused on bypassing the impact pressure is a free-turning type crusher equipped with a turning member having a fixed side rim and a turning side rim, which is mounted on an arm of a self-propelled work carriage. In, there is a hydraulic motor, the hydraulic motor has two ports for hydraulic fluid to flow in and out, and a rim-side gear that interlocks with the rotation-side rim, and a hydraulic motor-side that interlocks with the hydraulic motor and meshes with the rim-side gear. A bypass flow path is provided for bypassing between the gear and the port where hydraulic oil of the hydraulic motor flows in and out, and the bypass flow path is normally closed. It is a crusher characterized by communicating with the side.

Similar to the above-described structure, two bypass flow passages are provided between two ports for the hydraulic oil of the hydraulic motor to flow in and out, and relief valves are provided in the bypass flow passages in opposite directions to each other. Further, it is possible to employ a configuration in which a sub-bypass flow path in which a check valve is interposed is provided in parallel with the relief valve.

A bypass passage of two systems A and B is provided between the two ports for the hydraulic oil of the hydraulic motor to flow in and out, and two check valves are inwardly directed to the bypass passage on the A side. And two check valves are provided in the bypass passage on the B side so as to communicate with each other outward, and are provided in the intermediate portion between the check valves of the bypass passages A and B. Is provided with a relief valve, and when the pressure between the check valves of the bypass passage on the A side becomes equal to or higher than a predetermined pressure, the relief valve opens and the bypass passage on the A side to the bypass passage on the B side. A configuration in which hydraulic oil flows through is also recommended.

Further, the bypass passage is provided with a pilot switching valve and a resistance applying means for increasing the passage resistance, and the pilot switching valve becomes a high pressure of the hydraulic motor in response to the pressure of both ports of the hydraulic motor. A configuration in which the port and the resistance applying means are communicated with each other is also possible.

Further, the bypass flow passage is provided with two sets of one-way resistance means for allowing the flow in one direction and allowing the flow in the other direction only when the pressure exceeds a predetermined pressure. It is also possible to adopt a configuration in which all the directional resistance means allow the flow returning to the hydraulic motor side and are mounted in a direction in which the flow in the opposite direction is blocked.

Further, a pilot switching valve, a relief valve and a check valve are provided in the bypass passage, and the relief valve and the check valve are attached in a direction in which the check valve opens along the flow at the time of relief. The pilot switching valve may have a structure in which the high-pressure port of the hydraulic motor in response to the pressure of both ports of the hydraulic motor communicates with the inlet side of the relief valve.

Further, it is desirable that the bypass passage is provided with an excess / deficiency eliminating means for eliminating excess / deficiency of the hydraulic oil.

A fluid reservoir for accumulating hydraulic oil can be used as an excess / deficiency eliminating means.

Further, the excess / deficiency eliminating means is a fluid reservoir for accumulating the working oil, and it is also recommended that the pressurizing means for constantly pressurizing the working oil in the fluid reservoir is provided.

The excess / deficiency eliminating means may be provided in series or in parallel with the bypass passage.

Another structure of the present invention is an attachment for a construction machine, which is mounted on an arm of a self-propelled work carriage equipped with a hydraulic pressure generating device and has a turning mechanism which is turned by a turning hydraulic actuator. The main connection flow path connected to the hydraulic actuator is branched to have a branch flow path connected to the turning hydraulic actuator, and the branch flow path is provided with a closing / communication means for communicating when a predetermined pressure or more is reached. When the pressure in the main connection flow path becomes equal to or higher than a certain level, the closing / communication means communicates with each other, and the turning hydraulic actuator operates, which is an attachment for a construction machine. Further, a delay means is provided in the branch flow passage so that the closing / communication means communicates with each other when the pressure in the main connection flow passage exceeds a certain level, and the turning hydraulic actuator operates after the delay time has elapsed.

An example of a construction work attachment is a crusher having a crushing arm. An example of the hydraulic actuator is a hydraulic cylinder.

It is desirable that the branch flow path is branched from a portion on the supply side when the crushing arm is opened.

An example of the turning hydraulic actuator is a hydraulic motor.

Another structure of the present invention is an attachment for a construction machine, which is mounted on an arm of a self-propelled work cart and has a turning portion, has a hydraulic motor which is interlocked with the turning portion, and hydraulic oil of the hydraulic motor is A construction machine attachment that is provided with a bypass flow path that bypasses between ports that go in and out, is normally closed, and communicates from the high pressure side to the low pressure side when one of both ports reaches or exceeds a predetermined pressure. is there.

[0049]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram showing a hydraulic circuit of a crusher according to a first embodiment of the present invention and its related members.
FIG. 2 is a system diagram showing a hydraulic circuit of the crusher of the second embodiment and its related members. FIG. 3 is a system diagram showing a hydraulic circuit of the crusher of the third embodiment and its related members. Figure 4
[Fig. 6] is a system diagram showing a hydraulic circuit of a crusher of a fourth embodiment and its related members. FIG. 5 is a system diagram showing a hydraulic circuit of the crusher of the fifth embodiment and its related members. FIG. 6 is a system diagram showing a hydraulic circuit of the crusher of the sixth embodiment and its related members. FIG. 7 is a system diagram showing a hydraulic circuit of the crusher of the seventh embodiment and its related members. FIG. 8 is a front view of the crusher of the present invention. FIG. 9 is a circuit diagram showing a throttle valve with a relief function. FIG. 10 is a circuit diagram showing another component of the throttle valve with relief function.

The automatic turning type crusher which is the object of the present invention needs to have at least the hydraulic motor 5 installed. This hydraulic motor 5 is used for turning the crusher in the first to fourth embodiments. On the other hand, in the fifth to seventh embodiments, the hydraulic motor 5 is used for braking the turning. This crusher is roughly classified into two forms. In the double-rotation type crusher illustrated in FIG. 8, a frame is rotatably attached to a mounting bracket through a slewing bearing, and a pair of crushing arms that rotate is installed. It is pivotally attached to the frame. Although not shown, in the one-rotation crusher, the frame is rotatably attached to the mounting bracket via the slewing bearing, and the fixed arm projects forward from the frame, while the rotation arm is rotated near the base of the frame. It is freely pivoted and the pivot arm is arranged to face the fixed arm.

In the crusher 1 shown in FIGS. 1 and 8, the turning hydraulic motor 5 may be fixed to the horizontal plate 22 of the bracket 2, and the hydraulic motor 5 may be attached to the bracket itself or the mounting frame side. In the crusher 1, the inner rim 42 of the slewing bearing 4 is connected and fixed to the mounting frame 3, a rack 43 is engraved on the inner rim 42, and the shaft of the hydraulic motor 5 is attached to a pinion 44 that meshes with the rack 43. Link. In the configuration in which the hydraulic motor 5 is fixed to the bracket 2, when the hydraulic motor 5 is rotated, the crushing arms 33,
33 and the mounting frame 3 pivot horizontally with respect to the bracket 2.

The turning hydraulic motor 5 is arranged in the bracket 2 and is connected to the branch pipes 51 and 52 branching from the reciprocating hydraulic lines 89a and 89b connected to the arm opening / closing hydraulic cylinder 36, respectively. A throttle valve 53 with a relief function is interposed in the branch pipe 51 branched from the supply line 89a when the arm is opened, and a check valve is provided in the branch pipe 52 branched from the supply line when the arm is closed. 57 is interposed. The impact pressure bypass means 54 (frame of alternate long and short dash line) is interposed in the branch pipes 51, 52 at a portion extending from the throttle valve with relief function 53 or the check valve 57 to the connection port of the hydraulic motor 5.

In the above hydraulic circuit, as shown in FIG.
As shown in FIG. 5, the opening delay delaying means (delaying means) 60 may be interposed in the conduit between the throttle valve with relief function 53 and the hydraulic motor 5. When the hydraulic oil is supplied to the branch pipe 51 leading to the hydraulic motor 5, the opening operation delay cutoff means 60 opens the passage after a certain time has elapsed. With respect to the opening operation delay shutoff means 60, the internal volume of the pilot oil chamber (fluid cavity) 66 is increased, the gap between the piston 64 and the spool 61 is increased, or the throttle valve 68 is decreased, and these are reduced as desired. And the switching valve 70
The opening time of can be delayed more.

Further, instead of the opening operation delay cutoff means 60 of FIG. 2 or 3, an opening operation delay cutoff means (delay means) 100 as shown in FIG. 4 may be provided in parallel with the hydraulic motor 5. The opening operation delay shutoff means 100 is specifically a cylinder with no load or a light load, and includes a fluid cavity.

As shown in FIG. 9, the throttle valve with relief function 53 includes a known adjustable throttle valve 75 and adjustable relief valve 7.
6 is a component 53 in which 6 are connected in series. This throttle valve with relief function 53 has an adjustable throttle valve 75 as shown in FIG.
It is also possible to use a component element 53a in which a check valve 77 with adjustable cracking pressure is connected in series. Throttle valve 5 with relief function
3 shows that when the hydraulic pressure further rises after the hydraulic cylinder 36 stops at the fully opened position of the crushing arms 33, 33, the circuit is opened by the relief function, and the throttle valve 53 supplies the hydraulic motor 5 with the limited amount of oil. You can

The impact pressure bypass means 54 is the hydraulic motor 5
Adjustable relief valve 55 between the branch pipes 51, 52 connected to
Alternatively, the bypass flow paths 105 and 106 with the interposition of 55a are connected in parallel in opposite directions. Further, the impact pressure bypass means 54a shown in FIG. 3 may be used, and the oil passage 107 (bypass flow) that communicates with an arbitrary high pressure side between the branch pipes 51 and 52 via a pair of check valves 58 and 58. The oil passage 108 communicating with the passage A) to an arbitrary low pressure side via a pair of check valves 48, 48.
(Bypass flow path B) are respectively connected in parallel, and a communication path is connected between both check valves of the high-pressure side communication oil passage to both check valves of the low-pressure side communication oil passage. The adjustable relief valve 56 is interposed between the two.

The impact pressure bypass means 54 or 54a is
It is a means for protecting the equipment such as the hydraulic motor 5 by bypassing the impact pressure generated at the time of turning stop or when the careless overload is applied from the high pressure side to the low pressure side.
Even if an impact pressure acts on 9b, it can be released to the other side conduit.

Furthermore, the impact pressure bypass means 54b, 54c and 54d shown in FIGS. 5, 6 and 7 may be employed. The impact pressure bypass means 54b shown in FIG. 5 connects the ports Ma and Mb of the hydraulic motor 5 to each other by the bypass passage 1.
Connect with 03. As shown in FIG. 5, a pilot switching valve 15 is interposed in the bypass flow passage 103, and each port is connected to the ports on both ends of the spool of the pilot switching valve 15, so that when the hydraulic motor 5 is forcibly rotated by an external force, Extraction side or suction side ports can be individually selected and extracted. An adjustable relief valve 56 as a resistance means, an oil sump 14 and a check valve 57 are sequentially connected to one end of the port Mb, and the pilot switching valve 15 is again provided.
A circuit returning from the other port Ma of the above to the hydraulic motor 5 is constructed.

The configuration shown in FIG. 5 is an example in which the present invention is applied to a system in which the open / close arm is pressed against another member to forcibly rotate, and the hydraulic motor 5 is used for braking the rotation. . In the configuration shown in FIG. 5, when the open / close arm is pressed and swung forcibly, when the crusher receives a twisting action by biting the object, the hydraulic motor is driven via the pinion 44 that meshes with the rack 43 of the swivel bearing 4. 5 receives the rotational force, the port Mb of the hydraulic motor 5 switches the pilot switching valve 15 by the self pressure, and the adjustable relief valve 5 is adjusted.
6 and communicates with the adjustable relief valve 56 when the value exceeds the set value, the working oil flows in the bypass passage, the oil pressure motor 5 rotates, and the body mounting frame 3 of the crusher 1 has a constant braking force. It turns while receiving.

The pilot switching valve 15 is shown as a 2-position 4-way valve of parallel connection and cross connection in FIG. 5, but a 3-position 4-way valve having a fully closed position in the middle is used as shown in FIG. However, in that case, the check valve 57 can be omitted.

On the other hand, with respect to the bypass flow passage, there are various methods other than the above-mentioned method. For example, as shown in FIG. 6, both the ports Ma and Mb of the hydraulic motor 5 are provided with the adjustable relief valve 1.
6a, 16b and check valves 67a, 67b that allow only the flow to the hydraulic motor 5 side are connected in parallel, and the adjustable one-way resistance means are connected to each other, and the tips of the one-way resistance means are connected to each other. The oil reservoir 14 may be made to communicate with each other and the oil reservoir 14 may be interposed in the communication passage. In the case of this circuit configuration, the adjustable relief valve 16 of the one-way resistance means generates a constant resistance at an arbitrary port Mb of the hydraulic motor 5 even if it does not have a pilot switching valve, and the flow to the other port Ma is prevented. As a result, the hydraulic oil can be returned without resistance by passing through the check valve side provided in the sub-bypass passage.

Alternatively, as shown in FIG. 7, the bypass passage is connected to both ports Ma and Mb of the hydraulic motor 5 with a pilot switching valve 15b for selectively extracting the high pressure side as a high pressure port and the other as a low pressure port. And pilot switching valve 1
An adjustable relief valve 56 is interposed in the high pressure port of 5b, and the tip of the adjustable relief valve 56 is connected to the low pressure port of the pilot switching valve 15b, and a bypass flow passage 103b connecting the hydraulic motor 5 and the pilot switching valve 15 is connected. The hydraulic oil supply passages 71, 71 may be provided so as to communicate with the separately provided oil chamber of the oil sump 14 via check valves 72, 72 for blocking the reverse flow of high-pressure oil.

When the hydraulic fluid in the bypass passage 103 becomes excessive or deficient due to expansion / contraction or leakage of the hydraulic fluid due to temperature change or internal pressure, the oil sump 14 is in communication with the bypass passage 103, Although the excess or deficiency is automatically adjusted, it is convenient to provide the oil sump 14 with a pressurizing means in order to reliably supply and adjust the hydraulic oil and prevent cavitation.

In the press hand throwing, as shown in FIGS. 5, 6 and 7, the piston 101 and the spring 109 are housed in the cylindrical container, and the piston 101 is urged from the back to the oil chamber (oil sump 14). Pressurize the hydraulic oil inside or the spring 1
A suitable method may be used, such as enclosing a gas in place of 09 or accommodating a pradder enclosing a gas in place of the piston 101 and the spring 109.

In the crusher 1 shown in FIGS. 1 to 4, when the control valve 86 is switched to the cross passage position, the piston rod side R port of the arm opening / closing hydraulic cylinder 36 passes from the B port through the pipe line 89a and the swivel joint 24. The hydraulic oil is supplied to the hydraulic cylinder 36, and the hydraulic cylinder 36 is contracted to open the crushing arms 33, 33. At this time, since the arm opening operation of the crusher 1 has no load and the operating pressure is low, the throttle valve 5 with a relief function in the circuit of the hydraulic motor 5 for turning is provided.
3 remains closed.

When the arm reaches full open and the supply pressure rises, the relief valve 76 (FIG. 9) of the throttle valve 53 opens, and the working oil is supplied to the branch pipe 51 reaching the Mb port of the hydraulic motor 5 and the hydraulic motor 5 Rotates and the arms 33, 3 of the crusher 1
3 turns. The oil supplied to the hydraulic motor 5 is the throttle valve 53.
The adjustable throttle valve 75 limits the supply flow rate so that the hydraulic motor 5 has an appropriate rotation speed. On the other hand, since the Ma port of the hydraulic motor 5 communicates with the return side pipe line 89b of the hydraulic cylinder 36 via the check valve 57 of the branch pipe 52, the oil discharged from the hydraulic motor 5 is controlled from the Ma port. Return to the tank TK through the A port of the valve 86.

After turning the arms 33, 33 to a predetermined angle, the control valve 86 is returned to the neutral position, the supply of hydraulic oil is shut off, and the arm turning is stopped. Next, the work carriage is operated to move the arms 33, 33 of the crusher 1 into the disassembly target portion, and then the control valve 86 is switched to the parallel passage position.
As a result, the hydraulic oil is supplied from the A port of the control valve 86 to the C port on the head side of the hydraulic cylinder 36, the hydraulic cylinder 36 extends and the crushing arms 33, 33 close to perform crushing work. At this time, the supply pressure of the hydraulic oil becomes high, but the check valve 57 prevents the oil from flowing into the hydraulic motor 5 side, so that the hydraulic motor 5 does not rotate.

During the crushing operation, the opening / closing of the arm of the crusher 1 is repeated by operating the control valve 86. The control valve 86 is the arm 3
Immediately after or immediately before reaching the fully opened state of 33 and 33, if the neutral state is returned to or the arm is closed, the hydraulic motor 5 is not supplied with hydraulic oil and the arm does not rotate.

An abnormally high impact pressure acts on the hydraulic motor 5 when the hydraulic motor 5 is stopped, or the crusher 1 is operated during the crushing work.
There is a possibility that a large twisting force will act on the load and an excessive load will act. In this case, the impact pressure bypass means 54 operates to release the abnormally high pressure to the low pressure side. Impact pressure bypass means 5
No. 4, the built-in adjustable relief valve 55 or 55a relieves from the high-pressure port side to the low-pressure port side regardless of which of the Ma and Mb ports of the hydraulic motor 5 becomes high pressure, so that the impact pressure and the overload are prevented. The equipment such as the hydraulic motor 5 can be protected from any of the high pressures.

When the opening delay delaying means (delaying means) 60 shown in FIG. 2 is installed in the hydraulic circuit, the switching valve 70 keeps shutting off the circuit immediately after the hydraulic oil is supplied from the throttle valve 53. Immediately avoid rotating the hydraulic motor 5. The opening operation delay cutoff means 60 gradually supplies the hydraulic oil to the pilot oil chamber (fluid cavity) 66 through the thin throttle valve 68, and when the pilot oil chamber 66 is filled with the oil, pushes the spool 61 to open the switching valve 70. That is, the hydraulic oil is preferentially supplied to the pilot oil chamber (fluid cavity) 66. Therefore, since the arms 33, 33 of the crusher 1 are fully opened, the arm turning is started with a slight delay,
When the arm does not need to be turned, the control valve 86 may be switched back to the neutral position before the hydraulic oil passes through the opening delay delaying means 60.

When the cylindrical opening delay delaying means (delaying means) 100 shown in FIG. 4 is installed in the hydraulic circuit,
The hydraulic oil preferentially flows into the cylinder (fluid cavity) which is the opening operation delay cutoff means 100, and after the piston is completely extended to fill one oil chamber, the hydraulic oil is supplied to the hydraulic motor 5 side. . Therefore, the hydraulic oil does not flow to the hydraulic motor 5 immediately after the hydraulic oil is supplied from the relief valve 110, and the hydraulic motor 5 is prevented from rotating immediately.

Returning to the explanation of FIG. 3, when the control valve 86 is switched to the neutral position or the parallel passage position (arm closing operation side), the check valve 57 blocks the oil supply to the hydraulic motor 5. In the opening operation delay shutoff means 60, the pilot oil chamber 6
6 communicates with the hydraulic line 89a via the check valve 67, the switching valve 70 returns to shut off the circuit, and more reliably prevent the oil supply to the hydraulic motor 5.

Next, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the examples. As shown in FIG. 8, a crusher 1 equipped with a hydraulic circuit of the present invention has a pair of crush arms 3 in which an intermediate portion of a mounting frame 3 is rotatably pivoted by pins 38, 38.
3, 33 and the rear ends 35 of both crushing arms with pins 37, 3
The hydraulic cylinder 36 connected by 7 is arranged, and the tip end 34 of the crushing arms 33, 33 is opened and closed by the expansion and contraction operation of the hydraulic cylinder 36.

The crusher 1 is a hydraulic excavator (not shown).
Attached to the cylinder 8 on the arm 81 of the hydraulic excavator.
When 3 is expanded / contracted, the angle can be adjusted by rotating the bucket link 82 in the front-rear direction. As shown in FIGS. 1 and 4, the reciprocating pipeline of the hydraulic cylinder 36 includes a hydraulic valve 88, a control valve 86, a hydraulic pipe 84, and a tip hose 8 for the hydraulic excavator.
5, the bracket inner duct 89, the swivel joint 24 provided at the center of the slewing bearing 4, and the hose 25 to reach the hydraulic cylinder 36, and from the hydraulic cylinder, it returns to the tank TK in reverse order. The hydraulic power source 88 also serves as a hydraulic pump (not shown) for driving the hydraulic excavator, and is connected to the control valve 86 via the control valve 87. The control valve 86 is a three-position four-way valve which is controlled by operating a pedal (not shown) installed in the operator's cab and has three positions of neutral, parallel passage and cross passage. When the control valve 86 is operated to supply the hydraulic oil, the hydraulic cylinder 36 can be expanded / contracted to open / close the crushing arms 33, 33.

In the crusher 1, the mounting frame 3 is composed of an upper horizontal plate 32 and a pair of side plates 31 which are vertically fixed to the lower surface of the horizontal plate, and the bracket 2 is provided above the frame.
Is located. In the bracket 2, a pair of side plates 21 and 21 having mounting holes at the upper end are fixed to the horizontal plate 22, and pins 23 and 23 are inserted into the mounting holes so that the arms 8 of the hydraulic excavator are mounted.
The crusher 1 can be rotatably attached to the front end of the bucket link 1 and the bucket link 82. Further, the outer rim 41 is fixed to the horizontal plate 22 of the bracket 2, and the inner rim 42 is fixed to the upper horizontal plate 32 of the mounting frame 3, and the swivel bearing 4 fixes the rims 41,
42 is rotatably connected.

As shown in FIG. 1, the turning hydraulic motor 5
Is fixed on the horizontal plate 22 of the bracket 2. The pinion 44 is attached to the shaft 45 of the hydraulic motor 5, and the pinion 4
4 is a rack 4 engraved on the inner rim 42 of the slewing bearing 4.
Mesh with 3. When the hydraulic motor 5 is rotated, the mounting frame 3 and the crushing arms 33, 33 pivot horizontally with respect to the bracket 2.

The ports Ma, Mb of the hydraulic motor 5 are branched pipes 51, 5 branching from the pipe lines 89a, 89b in the bracket.
Connect to 2. The branch pipe 51 is connected to a line on the piston rod side of the hydraulic cylinder 36, and the throttle valve 5 with a relief function is connected.
3 intervenes. On the other hand, the branch pipe 52 is connected to a pipe line on the cylinder head side, and a check valve 57 for preventing the flow of oil to the hydraulic motor 5 side is interposed. The impact pressure bypass means 54 is interposed between the conduits from the throttle valve 53 or the check valve 57 to the hydraulic motor 5.

The throttle valve 53 with a relief function is a circuit component having both a function of blocking passage of hydraulic oil when the supply side pressure is equal to or lower than a set value and a function of limiting a passage flow rate. Specifically, the throttle valve 53 with a relief function
Is a component 53 in which an adjustable throttle valve 75 and an adjustable relief valve 76 are connected in series as shown in FIG. This throttle valve may be a constituent element 53a in which an adjustable throttle valve 75 and a check valve 77 with adjustable cracking pressure are connected in series as shown in FIG.

The impact pressure bypass means 54 is the hydraulic motor 5
The branch pipe 51 connected to the port Mb and the branch pipe 52 connected to the port Ma are bypass-connected by two pipe lines. An adjustable relief valve 55 from the branch pipes 51 to 52 is provided in one bypass passage, and the branch pipe 5 is provided in the other bypass passage.
There is an adjustable relief valve 55a from 2 to 51. When an impact pressure or a high pressure is applied to one of the ports Ma and Mb by the impact pressure bypass means 54, the adjustable relief valve 55 or 55a is actuated and is released to the port on the opposite side.

Next, a method of operating the crusher 1 will be described. When the control valve 86 of FIG. 1 is switched to the parallel passage side, the hydraulic oil of the hydraulic source 88 is P → A → 84 → 85 → 89b → A.
1 → A2 → C, while the hydraulic oil on the rod side of the cylinder 36 is R → B2 → B1 → 89a → 85 → 84 →
Flowing in the order of B → T, returning to the tank TK, the hydraulic cylinder 3
6 is extended to close the crushing arms 33, 33. When the control valve 86 is switched to the cross passage side, the hydraulic oil of the hydraulic power source 88 is P → B → 84 → 85 → 89a → B1 → B2 → R.
On the other hand, the hydraulic oil on the head side of the cylinder 36 flows in the order of C → A2 → A1 → 89b → 85 → 84 → A → T and returns to the tank TK to reduce the piston of the hydraulic cylinder 36. Open the crushing arms 33, 33.

At this time, when the crushing arms 33, 33 are fully opened and the operation pedal of the control valve 86 is continuously depressed in the arm opening direction to continue supplying hydraulic oil to the cylinder 36, the other conduit 89a, that is, the branch line 89a. The hydraulic pressure supplied to the pipe 51 increases. When the set pressure of the throttle valve 53 or more is reached, the adjustable relief valve 76 (FIG. 9) or the cracking pressure adjustable check valve 77 (FIG. 10) of the throttle valve 53 is opened to supply hydraulic oil to the hydraulic motor 5. . This hydraulic oil is supplied to the adjustable throttle valve 75.
Since the supply amount is limited in FIGS. 9 and 10, the hydraulic motor 5 does not rotate at high speed but rotates at an appropriate speed.

The crusher 1 is rotated by the hydraulic motor 5 and controlled to an arbitrary posture by the operation of the hydraulic excavator and the bucket link 82. When the arms 33, 33 are opened and closed, concrete lumps and the like can be crushed. Arm 33, 33
In the fully open state, if the control valve 86 is continuously operated in the arm opening direction as necessary, the crusher 1 can be further swung to adjust the position. Even if an abnormally high pressure is generated in the branch pipes 51 and 52 due to a twisting action during turning stop or during crushing work, this can be absorbed and eliminated by the impact pressure bypass means 54, and the hydraulic motor 5 is not damaged.

FIG. 2 shows a branch pipe 5 in addition to the hydraulic circuit of FIG.
In FIG. 1, the opening delay delaying means 60 is interposed.
The opening operation delay shutoff means 60 supplies the hydraulic oil to the hydraulic motor 5 with a slight delay after the crushing arms 33, 33 are fully opened, and the branch pipe 51 between the throttle valve 53 with a relief function and the hydraulic motor 5 is supplied. Attach to.

The opening operation delay shutoff means 60 has a switching valve 70 having two positions of shutoff and passage, and the spool 6 of the switching valve.
A spring 62 is arranged on one end surface of the No. 1 and a pressing means 65 having a pilot oil chamber 66 is arranged on the other end surface thereof. The spool 61 is normally urged to the blocking position by a spring 62. The pressing means 65 includes a cylinder serving as a pilot oil chamber 66, a piston 64 slidably accommodated in the cylinder, and a spring 63 for urging the piston in the oil discharge direction in the pilot oil chamber 66. When there is no pressure in the pilot oil chamber 66, the spring 63 pushes the piston 64 upward in FIG. 2, and the end surface of the piston is at a position having an appropriate gap with the end surface of the spool 61.

The opening operation delay shutoff means 60 includes a throttle valve 68.
The inlet port of the switching valve 70 via the pilot oil chamber 66
Provide a communication path to connect with. The pilot oil chamber 66 is connected to the upstream side of the throttle valve 53 via a check valve 67 as a return passage for the pilot oil.

In the hydraulic circuit shown in FIG. 2, the throttle valve 53 with a relief function is opened and the working oil is supplied to the switching valve 70. At the same time, the pilot oil is sent to the pilot oil chamber 66 through the throttle valve 68, and the piston Move 64 to the bottom of the figure. The piston 64 pushes the spool 61 after the movement time elapses because the gap between the piston 64 and the end surface of the spool 61 becomes zero. When the spool 61 moves, the switching valve 70 opens, whereby the hydraulic oil is sent to the hydraulic motor 5 via the switching valve 70, and the hydraulic motor 5 rotates to pivot the crushing arms 33, 33 of the crusher 1.

With respect to the opening operation delay cutoff means 60, when the inner volume of the pilot oil chamber 66 is increased, the gap between the piston 64 and the spool 61 is increased, or the throttle valve 68 is decreased, the opening time of the switching valve 70 is increased. Can be delayed more. As a result, the crushing arm 3
The time from the full opening of 3, 33 to the start of turning can be adjusted appropriately, and individual control of the crushing work and the turning operation can be facilitated and workability can be improved. For example, by setting the internal volume of the pilot oil chamber 66 to 50 cc or more, more preferably 100 cc or more, it is possible to secure an appropriate time from the full opening of the crushing arms 33, 33 to the start of turning.

FIG. 3 shows the hydraulic circuit of FIG. 2 having the opening delay delaying means 60, which is provided with an impact pressure bypass means 54a different from the above-mentioned means 54. The impact pressure bypass means 54a is connected to the port Mb of the hydraulic motor 5 by the branch pipe 5.
1 and the branch pipe 52 connected to the port Ma are bypass-connected by two pipe lines. On one oil passage 107 (bypass passage A), there are interposed check valves 58, 58 which face each other and through which oil can flow from the branch pipe 51 or 52, and on the other oil passage 108.
In the (bypass flow path B), the oil is both branched pipes 51 or 5
There are opposed check valves 48, 48 that can flow to A communication passage between the check valves 58 and 58 and between the check valves 48 and 48 is connected with the adjustable relief valve 56 from the check valves 58 to 48 interposed therebetween.

When an impact pressure or a high pressure is applied to any of the ports Ma and Mb by the impact pressure bypass means 54a, the working oil is supplied to the check valve 58, the relief valve 56 and the check valve in either the branch pipe 51 or 52. Through 48 towards the other branch. As a result, the generated impact pressure or high pressure can be released to the port on the opposite side.

FIG. 4 employs, in addition to the hydraulic circuit of FIG. 1, an opening delay delaying means (delay means) 100 of a different type from that of FIG. 2 described above. The opening delay delaying means 100 is a cylinder with no load or at least a lighter load than the hydraulic motor 5. The opening delay delaying means 100 is connected in parallel to the hydraulic motor 5. In this embodiment, the cylinder has a bore diameter of 60 mm and a stroke of about 50 mm. That is, the cylinder has a volume of 50 cc or more, preferably 1
Those of 00 cc or more are adopted. In this embodiment, as described above, the bore diameter is 60 mm, the stroke is about 50 mm, and the volume is about 140 cc.

Also in the embodiment shown in FIG. 4, the ports Ma and Mb of the hydraulic motor 5 are connected to the pipe lines 89a and 8 in the bracket.
It is connected to branch pipes 51 and 52 branched from 9b. Branch pipe 51
Is connected to a conduit 89a on the piston rod side of the opening / closing hydraulic cylinder 36, and a relief valve 110 and a throttle valve 111 are interposed. However, in this embodiment, bypasses are provided in both the relief valve 110 and the throttle valve 111, and the check valve 115,
116 is interposed. Each of the check valves is mounted in a direction that allows the flow from the outlet side to the inlet side of the relief valve 110 and the throttle valve 111. Relief valve 11
The pilot oil chamber of No. 0 is connected to the pipe line 89b on the cylinder head side via the pipe line 52. The connection channel 114
Is a flow path for discharging the hydraulic oil in the pilot oil chamber of the relief valve 110.

The downstream side of the throttle valve 111 is branched again, one of which is connected to the port Mb of the hydraulic motor 5 via the check valve 120, and the other of which is connected to the conduit on the A chamber (fluid cavity) side of the cylinder. ing. On the other hand, the other side of the cylinder on the B chamber side is provided with a hydraulic cylinder 3 for opening and closing the arm.
6 is directly connected to the pipe line 89b on the cylinder head side.

The port Ma of the hydraulic motor 5 is connected to a cylinder head side pipe 89b via a pipe 52 having a relief valve 121 with a check valve and a check valve 122.
Here, the check valve 122 blocks the flow of oil to the hydraulic motor 5 side. However, in this embodiment, the check valve 12
2 does not open below a certain pressure. Relief valve 121
Is for allowing a flow from the hydraulic motor 5 to the pipe line 89b on the cylinder head side when a certain pressure is exceeded.
Further, the check valve 125, which is provided by bypassing the relief valve 121, is attached in a direction that allows the flow of hydraulic oil to the hydraulic motor 5 side.

The pilot pressure of the relief valve 121 with a check valve connected to the port Ma of the hydraulic motor 5 is as shown in FIG.
Like the inlet side of the relief valve 121 (immediately before)
And from both the upstream side of the hydraulic motor 5. That is, in this embodiment, the pilot oil chamber of the relief valve 121 is connected to the branch pipe 51 on the downstream side of the throttle valve 111 via the pilot passage 113.

In this embodiment, the opening delay delaying means 100 is used.
The other side of the B chamber of the cylinder is directly connected to the line 89b on the cylinder head side of the hydraulic cylinder 36 for opening and closing the arm, so that the cylinder head side of the hydraulic cylinder 36 for opening and closing the arm has a high pressure. Then, the hydraulic oil is stored in the oil chamber B of one of the cylinders of the opening delay control unit 100. On the other hand, since the relief valve 110 is interposed in the pipe connected to the other oil chamber (A chamber),
During normal crushing work, hydraulic oil does not flow into the other oil chamber (A) even if the open / close arm is opened. When the working oil further flows into the oil chamber B, the working oil in the oil chamber A is discharged from the check valve 116,
After passing through 115, it exits to the side of the pipe 89a. Therefore, in the cylinder of the opening operation delay shutoff means 100, hydraulic oil always exists in only one oil chamber (B), and the other cylinder is in an empty state and stands by. Therefore, in this embodiment, when the opening / closing arm is closed, the working oil is always accumulated in one of the oil chambers (B chamber) of the cylinder of the opening delay blocking means 100.

Then, similarly to the previous embodiment, the crushing arm 3
When the operation pedals of the control valve 86 are further stepped on in the arm opening direction and the hydraulic oil is continuously supplied to the cylinder 36 in the fully opened state of 3, 33, the hydraulic pressure supplied to the branch pipe 51 increases,
The relief valve 110 opens. Then, the hydraulic oil flows into the branch pipe 51 via the throttle valve 111. Then, the hydraulic oil preferentially flows into the oil chamber A of the cylinder of the opening delay delaying means 100. That is, since the hydraulic motor 5 is constantly loaded, the cylinder of the opening delay delay shut-off means 100 has no load, so that the hydraulic oil first flows into the cylinder of the opening delay delay shut-off means 100. And one oil chamber (A)
After the hydraulic oil is filled in, the hydraulic oil flows to the hydraulic motor 5 side. When the oil chamber (A) is filled with hydraulic oil, the pressure between the throttle valve 111 and the cylinder rises, the hydraulic oil flows from the pilot flow passage 113 to the pilot oil chamber of the relief valve 121, and the relief valve 121 opens. Therefore, the flow path on the discharge side of the hydraulic motor 5 is secured. As a result, hydraulic oil flows through the hydraulic motor 5, the hydraulic motor 5 rotates, and the crushing arms 33, 33 pivot. That is, the crushing arms 33, 33
When the operation pedal of the control valve 86 is further depressed in the arm opening direction in the fully open state of FIG. . Therefore, the time from the fully opening of the crushing arms 33, 33 to the start of turning can be adjusted appropriately, and individual control of the crushing work and the turning operation can be facilitated and the workability can be improved.

In the embodiment of FIG. 4, the pilot pressure of the relief valve 121 is introduced from both the immediately preceding position and the upstream side of the hydraulic motor 5. The reason for introducing the pilot pressure from both the upstream side of the hydraulic motor 5 in this embodiment is to accelerate the reaction of the relief valve 121, and it is sudden that the pilot pressure is introduced from the position immediately before. This is because when the impact pressure is applied, the relief valve 121 is opened to release the pressure.

In the hydraulic circuit disclosed in this embodiment, the reciprocating pipeline for arm rotation attached to the hydraulic excavator and the three hydraulic pipelines serving as the drain pipeline can be omitted from the conventional crusher piping equipment. The control valve, the swing operation pedal, the swing control hydraulic system, and the swing hose that connects the tip of the pipe to the crusher are not required, which significantly reduces the cost of piping. When this hydraulic circuit is used, when the crusher is attached to and detached from the hydraulic excavator, only two connecting hoses need to be attached and detached, and the installation work time can be shortened.

The hydraulic circuit of the crusher of the present invention can operate the opening and closing of the crushing arm and the swiveling operation of the work trolley only by operating the arm opening and closing pedals and levers. Therefore, it is not necessary to change the operation pedal when turning the crushing arm,
The burden on the driver can be reduced.

In the embodiments shown in FIGS. 1 to 4 described above, the crusher is swung by the hydraulic motor 5, but the present invention uses a system in which the opening / closing arm is pressed against other members to swivel forcibly. Can also be adopted. Next, with reference to FIGS. 5, 6 and 7, an embodiment in which the present invention is applied to a system in which an opening / closing arm is pressed against another member to forcibly rotate will be described.

In this embodiment, the piping of the hydraulic motor 5 is completely independent from the arm opening / closing piping. That is, in the present embodiment, the inflow / outflow ports Ma and Mb of the hydraulic motor 5 are connected by the bypass flow passage 103, and the bypass flow passage 103 has an adjustable resistance means that acts on an arbitrary discharge side port of the hydraulic motor 5. 104 and the oil sump 14 communicating with the inflow side low pressure port are interposed, the hydraulic motor 5 generates a constant resistance against rotation in either forward or reverse directions, and the hydraulic oil is The excess and deficiency are adjusted automatically.

There are several examples of circuit configurations of the adjustable resistance means and the oil sump, which will be described later. Also in the crusher shown in FIGS. 5, 6 and 7, when the switching control valve 86 is switched to the parallel passage side, the hydraulic oil is
Similar to the previous embodiment, from the hydraulic power source 88, S → P → A → 89
Flowing in the order of b → A1 → A2 → C, the piston of the hydraulic cylinder 36 is extended to close the crushing arm tip 34 of the crusher 1, and the working oil on the piston rod side is R → B2 → B1 → 8.
9a → B → T, and then return to the tank TK.

When the switching control valve 86 is switched to the cross passage side, the hydraulic oil flows in the order of P → B → 89a → B1 → B2 → R, and the piston of the hydraulic cylinder 36 is pushed in to crush arm tip 34 of the crusher 1. And the hydraulic oil on the cylinder head side flows in the order of C → A2 → A1 → 89b → A → T and returns to the tank TK.

In this way, the tip of the crushing arm 34 of the crusher 1 can be arbitrarily opened and closed by operating the switching control valve 86. When crushing work is performed by the crusher 1, the crushing arm is opened, the hydraulic excavator is operated, and the tip of the crushing arm is applied to the object to be disassembled to adjust the opening / closing direction of the crushing arm and to drive the bucket link 82. The longitudinal angle of the crusher 1 is adjusted by expanding and contracting the bucket cylinder 83, and the crusher 1 is inserted into the crushing target portion. Then, the crushing arm is closed to crush the target part. At this time, the crusher may be eccentric and twisted during the crushing process.In this case, the crusher body frame swivels away in the twisting direction so that the arm opening / closing direction is at a right angle to the crushing point, and the posture is corrected naturally. Is done.

When the crusher main body frame is swung due to the twisting and twisting involved in the crushing work, the pinion 44 meshing with the rack 43 of the rim of the swivel bearing has the hydraulic motor 5
The hydraulic oil flows through the bypass passage 103 connected to the ports Ma and Mb of the hydraulic motor 5, and the bypass passage 103 acts on any discharge side port of the hydraulic motor 5 by an adjustable resistance means. Because 104 is interposed,
A constant resistance is generated with respect to the rotation in either the left or right direction, and the torque of the hydraulic motor 5 due to this resistance acts as a turning braking force that restricts the turning due to the crusher.

This turning braking force serves to prevent natural rotation associated with the change of the center of gravity associated with the opening and closing of the arm of the crusher, maintain a turning angle set in advance by turning around, and suppress excessive rotation due to inertia. .

The excess / deficiency of hydraulic oil in the circuit due to the turning operation, temperature change and internal leakage is automatically adjusted by the oil sump 14 communicating with the bypass passage. Next, each embodiment relating to the circuit configuration of the adjustable resistance manual throw and the oil sump interposed in the bypass channel 103 will be described. The bypass flow passage 103 of FIG. 5 includes both inflow and outflow ports Ma, of the hydraulic motor 5.
A 2-position 4-way pilot switching valve 15 having a parallel passage and a cross passage for selectively extracting an arbitrary discharge side (that is, high pressure side) and an inflow side (that is, low pressure side) from Mb is connected, An adjustable relief valve 56 serving as an adjustable resistance means 104 is connected to the high-pressure output side, and a check valve 57 that allows only the flow to the hydraulic motor 5 side is connected to the low-pressure side, and the check valve 57 is connected to the outlet side of the relief valve 56. The oil reservoir 14 is interposed between the check valves 57, and the oil reservoir 14 serves as the piston 10.
An appropriate pressure is applied to the low-pressure side port of the bypass flow passage by the pressurizing means composed of 1 and the spring 109 for urging the back surface.

In this circuit, when the main body frame receives a rotational force and the hydraulic motor 5 tries to rotate in either direction, the pressure at the discharge side ports of Ma and Mb passes through the pilot line (broken line). Then, the spool of the pilot switching valve 15 is pushed to communicate the discharge side port with the adjustable relief valve 56. Then, when the pressure of the discharge side port reaches the set pressure of the relief valve 56, the hydraulic motor 5 is relieved and rotates while generating a braking force, and the relief hydraulic oil is reverse-checked with the ports Q1 and Q2 of the oil sump 14. It returns to the inflow side port of the hydraulic motor 5 via the valve 57 and the low pressure side port of the pilot switching valve 15.

When an excess or deficiency of hydraulic oil occurs due to a change in the state of the circuit or the like, the oil sump 14 automatically adjusts this, and the additional pressure of the pressurizing means causes cavitation due to insufficient suction of the hydraulic motor 5. To prevent. The bypass flow passage 103a in FIG. 6 is provided with the adjustable relief valve 16a (16) for both the inlet and outlet ports Ma and Mb of the hydraulic motor 5.
b) and a check valve 67a allowing the flow to the hydraulic motor 5 side
Adjustable one-way resistance means 1 in which (67b) is connected in parallel
04a are connected to each other, and the oil reservoir 14 is interposed in the communication passage connecting the tips thereof. The oil reservoir 14 is provided with a bypass passage by a pressurizing means of the piston 101 and a spring 109 for urging the back surface. Appropriate pressure is applied inside.

In this circuit, any one of Ma and Mb serves as a discharge side port when the main body frame receives a rotational force and the hydraulic motor 5 is about to rotate in either direction, and the discharge pressure is an adjustable relief of the one-way resistance means. When the set pressure of the valve 16a (or 16b) is reached, the hydraulic motor 5 relieves and rotates while generating a braking force, and the relief working oil is used as the check valve 67 of the oil sump 14 and the other one-way resistance means.
It returns to the inflow side port of the hydraulic motor 5 via b (or 67a). When an excess or deficiency of hydraulic oil occurs due to a change in the state of the circuit or the like, the oil sump 14 automatically adjusts this, and the additional pressure of the pressurizing means prevents the occurrence of cavitation due to insufficient suction of the hydraulic motor 5.

A pilot switching valve 15b in three positions and four directions having a neutral passage, a parallel passage and a cross passage is connected to the bypass passage 103b in FIG. Then, the pilot switching valve 15b is automatically switched to selectively extract an arbitrary discharge side (that is, a high pressure side) and an inflow side (that is, a low pressure side) from both the inflow and exhaust ports Ma and Mb of the hydraulic motor 5. .
An adjustable relief valve 56 as a resistance means 104b is connected to the high pressure output side, the outlet side of the relief valve 56 is connected to the low pressure side of the pilot switching valve 15b, and
Each of the reciprocating passages connecting the hydraulic motor 5 and the pilot switching valve 15b has a circuit configuration in which a replenishing passage 71 having a check valve 72 communicates with a separately provided oil sump 14, and the oil sump 14 is connected to the piston 101. Spring 10 that urges this back surface
Appropriate pressure is applied to the bypass passage by the pressurizing means of 9.

In this circuit, when the main body frame receives a rotational force and the hydraulic motor 5 tries to rotate in either direction, the pressure at the discharge side ports of Ma and Mb passes through the pilot line (broken line). Then, the spool of the pilot switching valve 15b is pushed to connect the discharge side port to the adjustable relief valve 56. Then, when the pressure of the discharge side port reaches the set pressure of the relief valve 56, the hydraulic motor 5 relieves and rotates while generating a braking force, and the relief hydraulic oil passes through the low pressure side port of the pilot switching valve. Return to the inflow side port of the hydraulic motor 5.

When a shortage of hydraulic oil occurs due to a change in the state of the circuit, etc., the oil sump 1
4, the additional pressure of the pressurizing means prevents the occurrence of cavitation due to insufficient suction of the hydraulic motor 5. In the work of the crusher, in order to protect the crusher and hydraulic excavator from excessive twists that accompany the work, swing the main body frame to let it escape and stop it at the position where the crushing force works most effectively. When setting the crusher at the work site, hold it so that it does not turn carelessly due to interference with obstacles or eccentricity of the center of gravity, and if it is necessary to change the crushing arm opening / closing direction, use a hydraulic excavator. It is necessary to hit the crusher against a pillar or a wall by operation to accurately move the crusher up to the target angle. However, the hydraulic motor 5 stops the free rotation of the crusher, which stabilizes the hydraulic motor 5. The braking force is effective in smoothly and accurately performing these.

In the disc brake system that relies on mechanical frictional force like the conventional braking mechanism, the spring that presses the friction plate is loosened, and the friction plate is worn out, overheated, excessively deficient in the lubricating oil, or caught in foreign matter. It is easy and requires frequent adjustments and parts replacements, and the work requires time because it is not only skilled but also narrow and poor in workability, but the swing braking device of the present invention intervenes in the bypass passage of the hydraulic motor. It is a method of braking by generating a braking force on the hydraulic motor with an adjustable resistance means such as a relief valve, and the braking force can be adjusted accurately and extremely easily easily by setting the pressure of the resistance means, and there is little influence by temperature change, and it is always stable. In addition to maintaining high braking force and high reliability, there is no wear member such as a friction plate unlike the conventional mechanism, so long-term maintenance is not required, and durability is remarkably excellent.

The hydraulic motor pushes and rotates hydraulic oil, and if the suction side is forcibly rotated when there is no pressure, a negative pressure is generated due to the resistance of the internal passage, causing cavitation, which easily causes pain. An oil sump with a pressurizer is placed in the path to adjust the heat dissipation during braking, replenish internal leaks, change in volume due to temperature changes, etc. By taking measures against the cavitation of the motor, we have realized an excellent braking mechanism that can be used as braking means even with a normal hydraulic motor.

[0116]

As described above, according to the present invention, the problems associated with the crusher capable of automatically turning can be solved, and the turning hydraulic motor automatically rotates due to the pressure of the hydraulic oil sent to the hydraulic cylinder for opening and closing the arm. To be done. Further, according to the present invention, when the turning hydraulic motor is automatically turned, a time margin is given and operability is improved. Further, according to the present invention, the piping system dedicated to the turning is omitted to save the piping construction cost and the like, and the crusher can be attached to and detached from the hydraulic excavator in a short time.

Further, according to the present invention, when a shocking twist acts on the crusher during the crushing work, this twisting force can be smoothly released, and the breakage of the crusher can be prevented.

[Brief description of drawings]

FIG. 1 is a system diagram showing a hydraulic circuit of a crusher according to a first embodiment of the present invention and its related members.

FIG. 2 is a system diagram showing a hydraulic circuit of a crusher of a second embodiment and its related members.

FIG. 3 is a system diagram showing a hydraulic circuit of a crusher of a third embodiment and its related members.

FIG. 4 is a system diagram showing a hydraulic circuit of a crusher of a fourth embodiment and its related members.

FIG. 5 is a system diagram showing a hydraulic circuit of a crusher of a fifth embodiment and its related members.

FIG. 6 is a system diagram showing a hydraulic circuit of a crusher of a sixth embodiment and its related members.

FIG. 7 is a system diagram showing a hydraulic circuit of a crusher of a seventh embodiment and its related members.

FIG. 8 is a front view of the crusher of the present invention.

FIG. 9 is a circuit diagram showing a throttle valve with a relief function.

FIG. 10 is a circuit diagram showing another component of the throttle valve with relief function.

[Explanation of symbols]

1 crusher 5 Hydraulic motor for turning 16a, 16b Adjustable relief valve 36 hydraulic cylinder 51 branch pipe 52 Branch pipe 54, 54a Impact pressure bypass means 56,56a Adjustable relief valve 60 Opening operation delay cutoff means (delay means) 61 spool 62 spring 66 Pilot oil chamber (fluid cavity) 68 Throttle valve 75 Adjustable throttle valve 76 Adjustable relief valve 77 Check valve with adjustable cracking pressure 100 Opening operation delay cutoff means (delay means) 103 bypass flow path 104 resistance means 110 relief valve 111 throttle valve 120 check valve 125 check valve

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2D003 AA01 AB04 AC11 BA02 CA02                       DA02 DB02                 3H089 AA33 AA80 BB15 BB17 BB19                       BB27 CC01 CC08 CC11 DA02                       DB03 DB04 DB13 DB33 DB46                       DB49 GG02 JJ01

Claims (27)

[Claims] 1. A crusher equipped with a crushing arm mounted on an arm of a self-propelled work cart and opened and closed by a hydraulic actuator for opening and closing, and a crusher having a slewing mechanism swung by a hydraulic motor for slewing. There is a hydraulic flow passage communicating with the hydraulic fluid supply side when the crushing arm is opened or closed, and has a branched flow passage branched from the hydraulic fluid supply side. A closing / communication means that communicates when the pressure exceeds the pressure is provided, and a fluid cavity is provided on the downstream side of the closing / communication means.The pressure applied to the opening / closing hydraulic actuator when the crushing arm is opened or closed. When the pressure reaches or exceeds a predetermined pressure, the closing / communicating means communicates with each other, and the hydraulic oil preferentially flows into the fluid cavity, and then the hydraulic oil is supplied to the swing hydraulic motor and the swing hydraulic motor is supplied. A crusher that operates the data. 2. A hydraulic actuator for opening and closing in a crusher equipped with a crushing arm mounted on an arm of a self-propelled work cart and opened and closed by a hydraulic actuator for opening and closing, and a slewing mechanism swung by a hydraulic motor for slewing. There is a hydraulic flow passage communicating with the hydraulic fluid supply side when the crushing arm is opened or closed, and has a branched flow passage branched from the hydraulic fluid supply side. A closing / communicating means that communicates when the pressure exceeds the pressure is provided, and a delay means is further provided in the branch flow path, and the pressure applied to the opening / closing hydraulic actuator is equal to or more than a predetermined pressure when the crushing arm is in the open or closed state. The crusher is characterized in that hydraulic oil is supplied to the turning hydraulic motor and the turning hydraulic motor operates after a lapse of the delay time. 3. A hydraulic actuator for opening and closing in a crusher equipped with a crushing arm mounted on an arm of a self-propelled work carriage and opened and closed by a hydraulic actuator for opening and closing, and a slewing mechanism swung by a hydraulic motor for slewing. A portion having a reciprocating hydraulic flow path communicating with each other, a branch flow path branched from each of the hydraulic flow paths and connected to a turning hydraulic motor, and which is a supply side when the crushing arm is opened. The branch flow path branched from is provided with a closing / communication means and a delay means that are normally closed and communicate with each other when a predetermined pressure or more is reached, and the other branch flow path is operated toward the turning hydraulic motor side. A crusher characterized by being provided with a backflow prevention means for preventing the flow of oil. 4. The crusher according to claim 1, wherein the closing / communication means is composed of a relief valve and a throttle valve. 5. The crusher according to claim 4, wherein the relief valve is capable of adjusting an operating pressure. 6. The crusher according to any one of claims 1 to 5, wherein the turning hydraulic motor is provided with impact pressure bypass means. 7. The turning hydraulic motor has two ports through which hydraulic oil flows in and out, one or more bypass flow passages are provided between the ports, and the bypass flow passages are normally closed. The crusher according to any one of claims 1 to 6, wherein when one of both ports reaches a predetermined pressure or more, the high pressure side communicates with the low pressure side. 8. The turning hydraulic motor has two ports through which hydraulic oil flows in and out, two bypass flow paths are provided between the ports, and the bypass flow paths are provided with relief valves which are opposite to each other. The crusher according to any one of claims 1 to 7, further comprising a sub-bypass flow passage that is interposed in a direction and further has a check valve interposed in parallel with the relief valve. 9. A turning hydraulic motor has two ports through which hydraulic oil flows in and out, a bypass flow passage of two systems A and B is provided between the ports, and a bypass flow passage on the A side has two ports. The two check valves are provided so as to communicate with each other inwardly, and the two check valves are provided so as to communicate with each other outward at the bypass passage on the B side. A relief valve is provided at an intermediate portion between the check valves, and when the pressure between the check valves in the bypass passage on the A side becomes equal to or higher than a predetermined pressure, the relief valve opens to bypass the A side bypass. 9. The crusher according to claim 1, wherein the hydraulic oil flows from the flow passage to the bypass passage on the B side. 10. Attached to an arm of a self-propelled work cart,
In a crusher having a crushing arm that is opened and closed by an opening and closing hydraulic actuator and a slewing mechanism that is slewed by a slewing hydraulic motor, when the crushing arm is in an open state in a hydraulic flow path that communicates with the opening and closing hydraulic actuator. Has a branch flow path branched from the side to be the hydraulic oil supply side,
The branch flow passage is provided with a closing / communication means which is normally closed and communicates with the hydraulic actuator for opening / closing when the crushing arm is in the open state when the pressure reaches a predetermined pressure or higher. Then, the turning hydraulic motor operates, and the turning hydraulic motor further has two ports through which hydraulic oil flows in and out, and a bypass flow path for two systems A and B is provided between the ports, and Two non-return valves are interposed in the bypass flow passage so as to communicate with each other inwardly.
Two check valves are interposed in the bypass flow path on the side in a direction to communicate with each other outward, and a relief valve is provided at an intermediate portion between the check valves of the bypass flow paths A and B. When the pressure between the check valves of the bypass flow passage of No. 2 becomes equal to or higher than a predetermined pressure, the relief valve opens and the bypass flow passage from the A side of the bypass flow passage to B
Crusher characterized in that hydraulic oil flows through the bypass passage on the side. 11. The delay means includes a pilot switching valve having a pilot chamber having two positions of shutoff and communication, a communication passage connecting an inlet port side of the pilot switching valve with the pilot chamber, and the pilot chamber from the pilot chamber. The return flow path communicates with the upstream side of the closing / communication means via a check valve,
The spool of the pilot switching valve is constantly biased to a shut-off position by a biasing means, and when the pilot oil chamber is supplied with a certain amount or more of hydraulic oil, the spool is switched to the communicating position. The crusher according to 2 to 10. 12. The crusher according to claim 2, wherein the delay means is a hydraulic cylinder connected in parallel with the turning hydraulic motor. 13. The shredder according to claim 12, wherein the hydraulic cylinder operates at a pressure lower than that of the swing hydraulic motor. 14. Attached to an arm of a self-propelled work cart,
In a free swing type crusher having a swing member having a fixed side rim and a swing side rim, a hydraulic motor has a hydraulic motor, and the hydraulic motor has two ports through which hydraulic oil flows in and out, and is interlocked with the swing side rim. A rim-side gear, a hydraulic-motor-side gear that is interlocked with the hydraulic motor and meshes with the rim-side gear, and a bypass flow path that bypasses between the ports through which hydraulic oil of the hydraulic motor flows in and out are provided. The crusher is characterized in that the high pressure side and the low pressure side communicate with each other when one of both ports reaches a predetermined pressure or higher. 15. A bypass flow path of two systems is provided between two ports for the hydraulic oil of the hydraulic motor to flow in and out,
15. A bypass bypass passage in which a relief valve is interposed in the opposite direction to each of the bypass passages, and a check valve is interposed in parallel to the relief valve is provided. The crusher described. 16. A bypass flow path for two systems, A and B, is provided between two ports for the hydraulic oil of the hydraulic motor to flow in and out, and two check valves are mutually provided in the bypass flow path on the A side. And two check valves are provided in the bypass passage on the B side so as to communicate with each other outward, and an intermediate portion between the check valves of the bypass passages A and B. Is provided with a relief valve, and when the pressure between the check valves of the bypass passages on the A side becomes equal to or higher than a predetermined pressure, the relief valve opens and the bypass flow on the A side to the bypass flow on the B side. The crusher according to claim 14, wherein hydraulic oil flows through the passage. 17. The bypass flow passage is provided with a pilot switching valve and a resistance applying means for increasing the flow passage resistance, and the pilot switching valve becomes a high pressure of the hydraulic motor in response to the pressure of both ports of the hydraulic motor. The port and the resistance applying means are communicated with each other.
The crusher according to any one of 1. 18. The bypass flow passage is provided with two sets of one-way resistance means for allowing a flow in one direction and allowing a flow in the other direction only when a predetermined pressure is exceeded. 18. The crusher according to claim 14, wherein each of the one-way resistance means is mounted in a direction that allows a flow returning to the hydraulic motor side and blocks a flow in a direction opposite to each other. 19. The bypass passage is provided with a pilot switching valve, a relief valve and a check valve, and the relief valve and the check valve are attached in a direction in which the check valve opens along the flow at the time of relief. The crushing device according to any one of claims 14 to 18, wherein the pilot switching valve is responsive to the pressure of both ports of the hydraulic motor, and the high-pressure port of the hydraulic motor communicates with the inlet side of the relief valve. Machine. 20. The crusher according to claim 14, wherein the bypass flow passage is provided with an excess / deficiency eliminating means for eliminating excess / deficiency of the hydraulic oil. 21. The crusher according to claim 20, wherein the excess / deficiency eliminating means is a fluid reservoir for accumulating hydraulic oil. 22. The crusher according to claim 20, wherein the excess / deficiency eliminating means is a fluid reservoir for accumulating the hydraulic oil, and is provided with pressurizing means for constantly pressurizing the hydraulic oil in the fluid reservoir. Machine. 23. The crusher according to claim 20, wherein the excess / deficiency eliminating means is provided in series or in parallel with the bypass flow passage. 24. An attachment for a construction machine, which is mounted on an arm of a self-propelled work carriage equipped with a hydraulic pressure generating device and has a turning mechanism which is turned by a turning hydraulic actuator, is connected to another hydraulic actuator. A branch flow path that branches the connection flow path and is connected to the turning hydraulic actuator is provided with a closing / communication means that communicates when a predetermined pressure or more is reached. Is provided with a delay means, the closing / communication means communicates with each other when the pressure in the main connection flow path exceeds a certain level, and the turning hydraulic actuator operates after the delay time elapses. attachment. 25. The construction according to claim 24, wherein the attachment for construction work is a crusher having a crushing arm, the other hydraulic actuator is a hydraulic cylinder, and the crushing arm is opened and closed by the hydraulic cylinder. Mechanical attachment. 26. The attachment for a construction machine according to claim 24, wherein the branch passage is branched from a portion which is a supply side when the crushing arm is opened. 27. The attachment for a construction machine according to claim 24, wherein the turning hydraulic actuator is a hydraulic motor.