JP2020002647A - Attachment of work machine, and hydraulic operation valve for attachment of work machine - Google Patents

Abstract

To provide an attachment of a work machine and a hydraulic operation valve for an attachment capable of preventing an unexpected revolution of a work arm.SOLUTION: An attachment of a work machine includes: a hydraulic flow passage for opening and closing which makes a switching valve 20 communicate with a hydraulic motor 5 for revolving; a going-side branch flow passage 26 branching from a supply side of a hydraulic oil at the hydraulic flow passage for opening and closing when a crushing arm is in an open state and communicating with the hydraulic motor 5 for revolving; and a returning-side branch flow passage 27 which makes the hydraulic motor 5 for revolving communicate with the switching valve 20 and which returns the hydraulic oil passing the hydraulic motor 5 for revolving. An on-off valve 42 which is normally closed and communicates at a pressure equal to or higher than a predetermined pressure is interposed in the going-side branch flow passage 26 or the returning-side branch flow passage 27. In the returning-side branch flow passage 27, there are an on-off valve 50 and a relief valve 35. The on-off valve 50 includes: a valve seat including an opening; a valve body sealing the valve seat; pressing means pressing the valve body to the valve seat side; and release means separating the valve body from the valve seat. The hydraulic oil flows in a direction pressing the valve body to the valve seat.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an attachment mounted on a work machine such as a self-propelled work vehicle. The present invention also relates to an attachment hydraulically operated valve for a work machine that operates the attachment.

As an attachment mounted on the tip of an arm of a self-propelled work vehicle such as a hydraulic excavator, for example, a crusher, a gripper, a cutting machine, a shaker, and the like are known.
Focusing on the crushing machine, the crushing machine has a crushing arm like a finger or a crab claw, and opens and closes this crushing arm using a hydraulic cylinder.

When a building is dismantled using a 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 in accordance with the object to be crushed. Therefore, it is necessary to pivot the opening / closing arm as a whole. Here, as means for turning the crushing arm of the crusher, there is a method of turning by a hydraulic motor.
In addition, Patent Literatures 1 to 3 disclose techniques for supplying hydraulic oil to a hydraulic motor and simplifying piping for controlling the hydraulic motor.

The crusher disclosed in Patent Documents 1 to 3 branches a hydraulic circuit for opening and closing a crush arm, and connects a hydraulic motor to the branch. A relief valve is interposed in the branch flow path on the outward side with respect to the hydraulic motor.
In the conventional crushing machine, to rotate the crushing arm, hydraulic oil is supplied to a hydraulic cylinder of the crushing arm, and the crushing arm is expanded. If the crushing arm is extended to the limit and the hydraulic oil is further supplied to the hydraulic cylinder, the crushing arm of the hydraulic circuit opens and the pressure on the side increases, and the relief valve in the outgoing branch flow path opens, and hydraulic oil is supplied to the hydraulic motor. Then, the hydraulic motor rotates and the crushing arm turns.

JP-A-2000-27239 JP 2001-116005 A JP 2003-232301 A

According to the crushing machines disclosed in Patent Documents 1 to 3, the control valve for opening and closing the crushing arm and the control valve for rotating the crushing arm can be shared, and the piping system is greatly simplified.
By the way, in the crushing machines disclosed in Patent Documents 1 to 3, a phenomenon has occurred in which the crushing arm turns unintentionally. That is, when the crushing arm of the crusher hits something or makes a hit, the crushing arm turns beyond the expected range. In other words, the crushing arm turns around as if the force was lost.
Other attachments attached to the tip of the arm of the self-propelled work vehicle, such as a cutting machine, a grasping machine, and a shaking machine, also have parts that pivot similarly to the crusher, and have the same problem.
The present invention focuses on the above-mentioned problems of the prior art, and an object of the present invention is to provide an attachment of a working machine capable of preventing unexpected turning of a working arm of the attachment, and a hydraulically operated valve for the attachment of the working machine. It is assumed that.

The present inventors have studied the causes of the crushing arm pivoting beyond an expected range. As a result, during the turning operation, unintended leakage of hydraulic oil causes the amount of suction oil of the turning hydraulic motor to be insufficient, causing a vacuum state or sucking in outside air. It turned out that there might be cases.
An aspect completed based on this knowledge is an attachment of a working machine mounted on the working machine, the working arm being opened and closed by an opening and closing hydraulic actuator, and the working arm being driven by a turning hydraulic motor to turn the work arm. Turning mechanism, switching means for switching the flow direction of hydraulic oil supplied to the opening / closing hydraulic actuator, opening / closing hydraulic flow path communicating the switching means with the opening / closing hydraulic actuator, and opening / closing hydraulic flow path And an outgoing-side branch flow path that branches off from a side that is a supply side of hydraulic oil when the work arm is in an open state and communicates with the turning hydraulic motor, and communicates the turning hydraulic motor with the switching unit. It has a return-side branch flow path for returning hydraulic oil that has passed through the hydraulic motor for turning, and the forward-side branch flow path or the return-side branch flow path is normally closed. A closing / communicating means that communicates when the pressure reaches or exceeds a predetermined pressure is interposed, and when the pressure applied to the opening / closing hydraulic actuator reaches a predetermined pressure or more when the working arm is open, the closing / communicating means communicates. In the attachment of the working machine in which hydraulic oil is supplied to the turning hydraulic motor and the turning hydraulic motor operates, the return-side branch flow path has an opening / closing means and a back pressure generating means, and the opening / closing means has an opening. Having a valve seat, a valve body for sealing the valve seat, a pressing means for pressing the valve body toward the valve seat, and an opening means for separating the valve body from the valve seat, and the hydraulic oil comprises a valve body. An attachment for a working machine, characterized in that the attachment flows in a direction to press against a valve seat.

  Here, the attachment of the work machine is a crusher, a steel frame, which is attached to the tip of the work machine having a multi-joint arm (not a work arm) and crushes concrete structures, rubble, waste wood, and the like. It refers to a grabber that grabs rubble, waste wood, etc., and a cutting machine that cuts waste wood, steel frames, etc.

In the attachment of the working machine according to this aspect, the back pressure generating means is provided in the return-side branch flow path. The back pressure generating means is, for example, a relief valve, and can always apply an appropriate back pressure to the return side of the turning hydraulic motor.
Further, in the attachment of the working machine according to this aspect, an opening / closing means is provided in addition to the back pressure generating means.
Further, the opening / closing means employed in this aspect has a valve seat having an opening, a valve body for sealing the valve seat, and a pressing means for pressing the valve body toward the valve seat, and the operating oil Is for flowing the valve body in the direction of pressing against the valve seat.
In the opening / closing means employed in this aspect, the valve body is pressed against the valve seat by the pressing means, and the valve body is further pressed against the valve seat by the pressure of the hydraulic oil.
Therefore, the opening / closing means adopted in this aspect has a high sealing performance and a small leakage of hydraulic oil, so that it is possible to secure the hydraulic oil in the return-side branch flow path during the hitting operation, and to cause unexpected turning of the working arm. Can be prevented or suppressed.

  In the above aspect, it is desirable that the opening / closing means is a pilot check valve, and the opening means separates the valve body from the valve seat using pilot pressure.

  In the above aspect, it is desirable that the outgoing-side branch flow path is connected to the pilot port of the opening / closing means, and the valve element is separated from the valve seat when the pressure in the outgoing-side branch flow path becomes equal to or higher than a predetermined value.

It is desirable to open the opening / closing means as soon as hydraulic fluid is supplied to the turning hydraulic motor from the outward branch flow path. This embodiment satisfies this requirement.
In other words, when the pressure in the outgoing side branch flow path increases, the worker tries to turn the work arm, expands the work arm to the limit, and continues to supply the hydraulic cylinder to the hydraulic cylinder. This is the case where hydraulic oil is supplied to the hydraulic motor. Therefore, according to this aspect, when hydraulic oil is supplied to the turning hydraulic motor from the outward branch flow path, the opening / closing means opens.

  In each of the above aspects, the back pressure generating means is a relief valve, which may be provided on either side of the opening / closing means, but is preferably provided on the switching means side.

  In each of the above aspects, the turning hydraulic motor has a pair of ports through which hydraulic oil flows in and out, and when a shocking external force is applied to the turning hydraulic motor, an impact pressure bypass that short-circuits the pair of ports. It is desirable that the pressure-pressure bypass means, the closing / communicating means, the back-pressure generating means, and the opening / closing means be integrated.

  Another aspect for solving the above-described problem is a hydraulically operated valve for attachment of a work machine, which has a flow path on the outgoing side and a flow path on the return side, and has a hydraulic oil introduction valve at both ends of the flow path on the outgoing side. Side port A and a hydraulic oil supply side port C, and at both ends of a return side flow path, a hydraulic oil discharge side port B and a hydraulic oil return side port D. A closing / communicating valve that is closed and communicates when the pressure reaches or exceeds a predetermined pressure, and a forward-side check valve that allows a flow toward the hydraulic oil supply side port C and prevents the reverse flow; A flow path between the hydraulic fluid supply side port C and a port E that can communicate with the outside communicates with the port E. The return internal flow path has an open / close valve, and a back pressure is applied to the hydraulic oil discharge side port B side. An on-off valve, wherein the on-off valve is a pilot check valve, and has a valve seat having an opening; A valve body for sealing the valve body, a pressing means for pressing the valve body toward the valve seat, and an opening means for separating the valve body from the valve seat, wherein the hydraulic fluid flows in a direction to press the valve body against the valve seat. The flow path between the back pressure generating valve and the hydraulic oil discharge side port B communicates with a port F that can communicate with the outside, and further has an impact pressure bypass flow path. A hydraulically operated valve for an attachment of a working machine, wherein the pair of ports C and D are short-circuited when an impact external force is applied to the hydraulic oil supply side port C or the hydraulic oil return side port D. is there.

  Another aspect is mounted on an attachment including a work arm driven to be opened and closed by a drive cylinder, a turning mechanism driven by a turning hydraulic motor to turn the work arm, and a switching valve for opening and closing the work arm. A hydraulic operating valve for attachment that connects between the switching valve and the hydraulic motor for turning, a hydraulic oil introduction side port A connected to the switching valve, a hydraulic oil discharge side port B, and the turning hydraulic pressure. A hydraulic oil supply side port C connected to the motor, a hydraulic oil return port D, and an internal flow path on the outgoing side connecting the hydraulic oil introduction side port A and the hydraulic oil supply side port C therein; A return-side internal flow path that connects the side port B and the hydraulic oil return-side port D, and a closing / communication valve that is normally closed and communicates when the pressure reaches or exceeds a predetermined pressure, A forward-side check valve that permits flow toward the hydraulic oil supply side port C and prevents the reverse, and a flow path between the closing / communication valve and the hydraulic oil supply side port C can communicate with the outside. The return-side internal flow path has an on-off valve, a hydraulic oil discharge-side port B side has a back pressure generating valve, and the on-off valve is a pilot check valve. A valve seat having an opening, a valve body for sealing the valve seat, a pressing means for pressing the valve body toward the valve seat, and an opening means for separating the valve body from the valve seat. It flows in the direction in which the valve element is pressed against the valve seat. The flow path between the back pressure generating valve and the hydraulic oil discharge side port B communicates with a port F that can communicate with the outside. The impact pressure bypass flow path applies a shocking external force to the hydraulic oil supply port C or the hydraulic oil return port D. It said pair of ports C upon Tsu, a working machine hydraulic valve attachment, characterized in that those shorting D.

  In these embodiments, it is preferable to have a delay cylinder with a piston movable inside, and that the ports E and F communicate with regions on both sides of the piston in the delay cylinder, respectively.

  Here, the attachment of the work machine is a crusher that is attached to the tip of the articulated arm (not the work arm) of the work machine and crushes concrete structures, rubble, waste wood, etc., steel frames, rubble, waste wood, etc. It is assumed that a grabber that grabs the wood, a cutting machine that cuts waste wood and steel frames, and a shaker that sorts rubble and the like are assumed. A shaker is a swing machine in which a bucket provided with a shake drum is pivotably supported at the tip of an arm of a work machine.

  The use of the hydraulic valve for attachment of the work machine of this embodiment further simplifies the installation of the hydraulic piping of the attachment.

  An aspect related to this aspect is a crusher mounted on an arm of a self-propelled work vehicle, wherein the crushing arm is opened and closed by an opening and closing hydraulic actuator, and the crushing arm is driven by a turning hydraulic motor. A switching mechanism for switching the flow direction of hydraulic oil supplied to the opening / closing hydraulic actuator; an opening / closing hydraulic flow path communicating the switching means with the opening / closing hydraulic actuator; A forward branch flow path that is branched from a side that is a supply side of hydraulic oil when the crushing arm is in an open state and that communicates with the turning hydraulic motor; and the turning hydraulic motor and the switching unit. A return-side branch flow path for returning hydraulic oil that has passed through the communication turning hydraulic motor; and the forward-side branch flow path or the return-side branch flow path is always closed and has a predetermined pressure or less. When the crushing arm is in an open state and the pressure applied to the opening / closing hydraulic actuator reaches a predetermined pressure or more, the closing / communication means communicates and the turning hydraulic pressure is established. In a crusher in which hydraulic fluid is supplied to a motor and a turning hydraulic motor operates, the return-side branch flow path has an opening / closing means and a back pressure generating means, and the opening / closing means has a valve seat having an opening, A valve body for sealing the valve seat, pressing means for pressing the valve body toward the valve seat, and opening means for separating the valve body from the valve seat; This is a crusher characterized by flowing through the crusher.

  Further, another aspect related to this aspect includes a crushing arm driven by a crushing cylinder, a turning mechanism driven by a turning hydraulic motor to turn the crushing arm, and a switching valve for opening and closing the crushing arm. A hydraulically operated valve for a crusher mounted on a crusher and connecting the switching valve and the hydraulic motor for turning, wherein a hydraulic oil introduction side port A and a hydraulic oil discharge side port B connected to the switching valve. A hydraulic oil supply side port C connected to the turning hydraulic motor, and a hydraulic oil return side port D, and a forward internal flow connecting the hydraulic oil introduction side port A and the hydraulic oil supply side port C therein. And a return internal passage connecting the hydraulic oil discharge side port B and the hydraulic oil return side port D. The return internal passage is normally closed and communicates when a predetermined pressure or more is reached. Closure / communication valve and operation A port that allows a flow toward the supply port C and prevents the reverse flow, and wherein a flow path between the closing / communication valve and the hydraulic oil supply port C can communicate with the outside. E, the return-side internal flow path has an on-off valve, a hydraulic oil discharge port B side has a back pressure generating valve, and the on-off valve is a pilot check valve; A valve seat that seals the valve seat, a pressing unit that presses the valve body toward the valve seat, and an opening unit that separates the valve body from the valve seat. Flows in the direction of pressing against the valve seat. The flow path between the back pressure generating valve and the hydraulic oil discharge side port B communicates with a port F that can communicate with the outside, and further has an impact pressure bypass flow path. In the impact pressure bypass flow path, a shocking external force is applied to the hydraulic oil supply side port C or the hydraulic oil return side port D. The pair of port C in a crusher hydraulic operated valve, characterized in that those shorting D.

  The attachment of the working machine of the present invention is less likely to cause unexpected turning of the working arm. Similarly, the attachment of the work machine using the hydraulically operated valve for attachment of the work machine of the present invention is unlikely to cause unexpected turning of the work arm. Further, by using the hydraulically operated valve for attachment of a working machine according to the present invention, the hydraulic piping of the attachment of the working machine can be completed with a simple operation.

It is a front view of the crusher concerning embodiment of this invention. It is a piping system diagram of the crusher of FIG. FIG. 2 is a system diagram of a hydraulically operated valve for a crusher employed in the crusher of FIG. 1. FIG. 2 is a cross-sectional view of an opening / closing valve (opening / closing means) used in the crusher of FIG. 1, showing a state in which a valve body is pressed by a valve seat and a flow path is closed. FIG. 2 is a cross-sectional view of an opening / closing valve (opening / closing means) employed in the crusher of FIG. 1, showing a state in which a valve body is pressed by an opening means and separated from a valve seat to open a flow path. FIG. 2 is a cross-sectional view of an opening / closing valve (opening / closing means) employed in the crusher of FIG. 1, showing a state where a valve body is opened against a pressing force of a pressing means. FIG. 5 is an exploded perspective view showing the internal structure of the on-off valve (opening / closing means) in FIG. 4. FIG. 4 is a piping system diagram of a crusher according to another embodiment different from FIG. 2. FIG. 9 is a cross-sectional view of the on-off valve functioning as the closing / communicating means in FIG. 8, where (a) illustrates a closed state and (b) illustrates an opened state. (A) is a perspective view of the hydraulically operated valve for the crusher observed from the front side, and (b) is a perspective view of the hydraulically operated valve for the crusher observed from the back side.

Hereinafter, embodiments of the present invention will be further described.
As attachments to be attached to the arm of a working machine such as a self-propelled work vehicle having an arm, there are a crusher, a gripper, a cutting machine, a shaker, and the like, and the crusher will be described below.

First, the mechanical structure of the crusher 1 of the present embodiment will be described.
The crusher 1 (attachment) of the present embodiment is attached to the tip of an arm 8 (FIG. 1) of a self-propelled work vehicle (work machine), and has an intermediate portion pivotally connected to be freely opened and closed by pins 2 and 2. It has a pair of crushing arms 3, 3 (working arms). The arm 8 has a plurality of joints and can freely move the distal end portion to a desired position. FIG. 1 shows only the distal end portion. An opening / closing hydraulic cylinder (opening / closing hydraulic actuator; drive cylinder) 10 is connected to the rear ends of both crushing arms 3, 3 via pins 7, 7, and the opening / closing hydraulic cylinder 10 (crushing cylinder) is provided. The distal ends of the crushing arms 3 are driven to open and close by expanding and contracting.
Further, the crusher 1 of the present embodiment has a hydraulic motor 5 for turning. The turning hydraulic motor 5 has a pair of ports through which hydraulic oil flows. By passing hydraulic oil from one port of the turning hydraulic motor 5 to the other port, the crushing arms 3 can be turned. That is, the crushing arms 3 have a turning mechanism 6, and the turning mechanism 6 is driven by the turning hydraulic motor 5. When the turning mechanism 6 is driven, the crushing arms 3 turn. The turning mechanism 6 is not a main part of the present invention, but has a known structure, and illustration and description of the internal structure of the turning mechanism 6 are omitted.

Next, the hydraulic circuit of the crusher 1 (attachment) will be described.
The hydraulic circuit of the crusher 1 is as shown in FIG. 2 and includes a basic pipe 11, an opening / closing hydraulic flow path 12, and a turning branch flow path 13.
The base pipe 11 includes a hydraulic oil tank 16 (FIG. 2) and a hydraulic pump 17 (FIG. 2) provided on a self-propelled work vehicle (not shown) such as a hydraulic shovel equipped with the crusher 1 (FIG. 1). It is a piping system that has the switching valve 20 (switching means) and connects them.
The opening / closing hydraulic flow path 12 is a pipe connecting the switching valve 20 and the opening / closing hydraulic cylinder 10, and supplies the hydraulic oil discharged from the switching valve 20 to the opening / closing hydraulic cylinder 10 or switches from the opening / closing hydraulic cylinder 10. This is a flow path for returning hydraulic oil to the valve 20 side.

In this embodiment, when hydraulic oil is supplied to the bottom side 21 of the opening / closing hydraulic cylinder 10, the crushing arms 3, 3 are closed. Conversely, when hydraulic oil is supplied to the rod 22 side of the opening / closing hydraulic cylinder 10, the crushing arms 3, 3 open.
In the present embodiment, a flow path (hereinafter referred to as an arm open side flow path) 23 connecting the switching valve 20 and the rod 22 side of the opening / closing hydraulic cylinder 10 is connected to a supply side of the hydraulic oil when the crushing arms 3 are opened. It becomes. A flow path connecting the switching valve 20 and the bottom side 21 of the opening / closing hydraulic cylinder 10 is an arm closing side flow path 25.

In the present embodiment, the turning branch flow path 13 is branched from the arm opening side flow path 23 of the opening / closing hydraulic flow path 12, and reaches the turning hydraulic motor 5. And a return-side branch flow path 27 (return-side internal flow path 102) that connects the turning hydraulic motor 5 and the arm-closed-side flow path 25 and reaches the switching valve 20. The return-side branch flow path 27 is a flow path that communicates the turning hydraulic motor 5 with the switching valve 20 (switching means) and returns the hydraulic oil that has passed through the turning hydraulic motor 5 to the hydraulic oil tank 16 side.
The flow of hydraulic oil in the turning branch flow path 13 enters the outgoing-side branch flow path 26 from the switching valve 20, passes through the turning hydraulic motor 5, flows into the return-side branch flow path 27, and returns to the switching valve 20. , And the flow in this direction is referred to as “forward direction”. The flow in the opposite direction is called "reverse direction".

  The first throttle valve 30, the on-off valve 42 (closing / communicating means, or the closing / communicating valve), and the second throttle valve 32 are arranged in the outgoing-side branch flow path 26 in the forward flow direction of the hydraulic oil as shown in FIG. , A check valve 33 (an outgoing check valve) is interposed. The on-off valve 42 is a normally-closed valve as described later, and is opened by pilot pressure. The check valve 33 is mounted in a direction that allows the flow of hydraulic oil in the forward branch flow path 26 in the forward direction and prevents the flow in the reverse direction.

In the return-side branch flow path 27, an opening / closing valve 50 (opening / closing means) and a relief valve (back pressure generating means or back pressure generating valve) 35 are interposed in the order of forward flow of the hydraulic oil.
The on-off valve 50 is a pilot check valve as described later, and blocks a forward flow in the return-side branch flow path 27 and allows a reverse flow. That is, the on-off valve 50 is a check valve attached in a direction for preventing the flow in the normal direction in the return-side branch flow path 27.
However, the on-off valve 50 receives the pilot pressure and opens to allow forward flow.

  The relief valve 35 opens when the pressure on the introduction side exceeds a certain value, and functions to keep the pressure on the introduction side constant. Further, in this embodiment, the relief valve 35 has a certain check function, and prevents the hydraulic oil from flowing in the reverse direction to some extent.

The downstream side of the on-off valve 42 in the outgoing side branch flow path 26 is further branched and connected to one cavity 45 of the delay cylinder 36 (delay hydraulic oil introduction cavity). The other cavity (opposite side cavity) 46 of the delay cylinder 36 is connected to the return side branch flow path 27 downstream of the relief valve 35. Here, the cavities 45 and 46 are regions on both sides of the piston 44 in the delay cylinder 36.
The hydraulic circuit of the crusher 1 is configured by connecting the respective members and valves as described above.

Next, a detailed structure of the opening / closing valve 50 (opening / closing means) provided in the return-side branch flow path 27 will be described.
In the present embodiment, a pilot check valve is employed as the on-off valve 50. As shown in FIG. 4, the on-off valve (pilot type check valve) 50 includes a valve body 52, a pressing means 53, a valve body side pressing member 75, an opening means 55, and an opening means side holding inside a tubular main body 51. A member 77 and an opening spring 82 are built in.

  As shown in FIG. 4, the main body 51 of the on-off valve 50 has a penetrated cylindrical shape. That is, a through hole extending along the main body 51 is formed inside. The through hole of the main body 51 has a structure in which a large diameter hole and a small diameter hole are continuous. A relatively large-diameter hole is provided near both ends of the main body 51, and a relatively small-diameter hole constituting the space 69 is provided in the central portion of the main body 51. That is, there are large-diameter holes on both sides of the space 69, and these are continuous.

  The opening of one large-diameter hole functions as the introduction port 56. A step portion 60 is formed at a connection portion between the large-diameter hole on the introduction port 56 side of the main body 51 and the central space 69 (small-diameter hole). The opening of the step portion 60 functions as a valve seat 61.

  The other large-diameter hole of the main body 51 functions as a pilot port 58. The pilot port 58 is provided with an opening means 55 (large-diameter portion 55a) described later. A step portion 76 is formed at a connection portion between the large-diameter hole on the pilot port 58 side and the central space 69 (small-diameter hole).

  In addition, an opening that functions as a discharge port 57 that communicates with the introduction port 56 is provided on a side surface (a part of the cylinder) of the main body 51. That is, the discharge port 57 is provided at a portion of the main body 51 where the space 69 (small-diameter hole) is formed, and communicates with the space 69. A screw 57a is provided near the opening of the discharge port 57. As shown in FIG. 4, the flow path from the introduction port 56 to the discharge port 57 has a substantially L-shape.

A screw 96 is formed on the inner surface of the main body 51 and near the introduction port 56 side.
A screw 97 is provided on the inner surface of the main body 51 and near the pilot port 58 side.

A valve body-side pressing member 75 is screwed and attached to the screw 96. That is, a screw that is screwed with the screw 96 of the main body 51 is provided on the outer peripheral surface of the valve body-side pressing member 75. The valve body-side pressing member 75 is a cylindrical member having a through hole 78.
The valve body-side pressing member 75 attached to the main body 51 has a form like an inward flange that partially narrows the inner diameter of the large-diameter hole on the introduction port 56 side of the main body 51.
A space 79 is formed between the valve body-side pressing member 75 and the step portion 60.
The space 79 is partitioned by the step portion 60, the valve body-side pressing member 75, and the inner wall of the main body 51.
The space 79 is continuous with the space 69 which is a small-diameter hole.

  The valve body 52 and the pressing means 53 are arranged in the space 79.

  The valve element 52 is a substantially columnar member having a relatively large diameter portion and a relatively small diameter portion. The relatively large-diameter portion of the valve body 52 constitutes a sliding surface, and can slide with respect to the inner wall of the large-diameter hole of the main body 51 while maintaining liquid tightness. When the valve body 52 is disposed in the space 79, an annular space 79a is formed between the main body 51 and a small-diameter portion of the valve body 52.

As shown in FIG. 4, a concave portion 65 is provided inside the valve body 52. The concave portion 65 is open on the large-diameter hole side of the valve body 52. A spring engaging portion 52a is provided on the inner wall near the opening of the concave portion 65. The spring engaging portion 52a is formed by an annular step provided on the inner wall of the concave portion 65. At a plurality of locations on the side surface of the valve body 52, communication holes 52b for communicating the recess 65 with the annular space 79a are provided. The annular space 79a is always in communication with the introduction port 56 via the through hole 78 of the valve body-side pressing member 75 and the concave portion 65 in the valve body 52.
Further, a tapered surface 62 is provided at an end of the valve body 52 opposite to the concave portion 65.

The pressing means 53 is a compression spring.
The pressing means 53 is contracted between the valve body-side pressing member 75 and the spring engaging portion 52 a of the valve body 52. The pressing means 53 has a function (valve closing function) of urging the valve body 52 toward the valve seat 61 and seating the valve body 52 on the valve seat 61.
When the valve body 52 sits on the valve seat 61 (closes the valve), the annular space 79a and the space 69 (small-diameter hole) are shut off, and when the valve body 52 separates from the valve seat 61 (opens), the space is opened. 79a and space 69 communicate.

  An opening means-side pressing member 77 is screwed into the screw 97 of the main body 51. That is, a screw which is screwed with the screw 97 of the main body 51 is provided on the outer peripheral surface of the opening means side pressing member 77. The opening means side holding member 77 is a cylindrical member having a through hole 80.

  A space 81 is formed by the opening means-side pressing member 77, the inner wall of the main body 51, and the stepped portion 76. In the space 81, an opening means 55 and an opening spring 82 are arranged.

The opening means 55 is a member having a large diameter portion 55a and a small diameter portion 55b. The large diameter portion 55 a of the opening means 55 is arranged in the space 81. The small-diameter portion 55b of the opening means 55 protrudes and extends into a space 69 (small-diameter hole) of the main body 51.
The outer diameter of the large diameter portion 55a substantially matches the inner diameter of the space 81. Therefore, the large-diameter portion 55a is slidable along the inner wall of the space 81 of the main body 51 while maintaining liquid tightness.
The outer diameter of the small diameter portion 55b is slightly smaller than the hole 72 formed in the step portion 76, and smaller than the hole formed in the step portion 60.
There is a slight gap between the small diameter portion 55b and the hole 72 formed in the step portion 76, and liquid tightness is not maintained between the two. Therefore, the space 69 and the space 81 communicate with each other via a slight gap. When the small diameter portion 55b enters the hole of the step portion 60, an annular gap is formed between the small diameter portion 55b and the hole of the step portion 60.
The tip of the small diameter portion 55b is close to the valve body 52.

  An open spring 82 is arranged in the space 81. The opening spring 82 is a compression spring, and is contracted between the stepped portion 76 and the large diameter portion 55 a of the opening means 55. The large-diameter portion 55a of the opening means 55 pressed by the opening spring 82 comes into contact with the opening means pressing member 77 on the pilot port 58 side and stops. At this time, the tip of the opening means 55 on the small diameter portion 55 b side is close to the valve element 52.

  When a working oil pressure that overcomes the urging force of the opening spring 82 acts on the opening means 55 from the pilot port 58 side, the opening means 55 can move along the main body 51 against the urging force of the opening spring 82. At that time, the hydraulic oil in the space 81 is pushed out to the space 69 side from between the hole 72 and the small-diameter portion 55b (a slight gap). When the opening means 55 moves, the front end portion on the small diameter portion abuts on the valve body 52 and presses the valve body 52 to open the valve (ie, separates the valve body 52 from the valve seat 61).

The valve body 52 is constantly pressed against the valve seat 61 by the pressing means 53, and the tapered surface 62 of the valve body 52 is always in contact with the corner of the opening (the valve seat 61) of the step portion 60 and is closed.
Therefore, the valve seat 61 is closed by the valve body 52, and the space 79 on the introduction port 56 side and the space 69 on the discharge port 57 side are closed. That is, the introduction port 56 and the discharge port 57 are shut off.
Since the hydraulic oil flows from the introduction port 56 toward the discharge port 57, the valve body 52 is pressed against the valve seat 61 by the pressure of the hydraulic oil.

  On the other hand, when hydraulic oil is introduced from the discharge port 57 side, the hydraulic oil presses the valve element 52, and separates the valve element 52 from the valve seat 61 as shown in FIG. That is, the on-off valve 50 opens.

  The on-off valve 50 presses the valve body 52 against the opening of the valve seat 61 to close it, and the valve body 52 is constantly urged toward the valve seat 61 by the urging force of the pressing means 53 and the pressure of the hydraulic oil. ing. Therefore, the on-off valve 50 has high sealing performance and little leakage.

Next, the on-off valve 42 (closing / communicating means or closing / communicating valve) provided in the outgoing-side branch flow path 26 shown in FIG. 2 will be described.
The opening / closing valve 42 has the same structure as the opening / closing valve 50 (opening / closing means) provided in the return-side branch flow path 27, and redundant description will be omitted.

  That is, the on-off valve 42 is a pilot check valve, which allows the passage of fluid in only one direction and prevents the flow in the reverse direction. Fluid can flow through the The on-off valve 42 constitutes the combination valve 31 together with the pilot circuit section 66 as shown in FIG.

  The pilot circuit section 66 includes the relief valve 43 and the check valve 67. The relief valve 43 is a valve that allows a flow from the input side to the output side when the input pressure exceeds a certain pressure. The check valve 67 has an effect of easily removing the secondary pressure of the relief valve 43 and improving the closing response of the on-off valve 42. In the present embodiment, when the pressure of the outgoing side branch flow path 26 exceeds a certain value, the relief valve 43 is opened, the pilot pressure is applied to the on-off valve 42, the check mechanism is released, and the fluid can flow in both directions. It becomes.

  As shown in FIG. 2, the on-off valve 42 (combination valve 31) is provided between the first throttle valve 30 and the second throttle valve 32 in the outgoing-side branch flow path 26. In the present embodiment, a check valve 34 is connected to the outgoing-side branch flow path 26 in parallel with the combination valve 31. That is, the check valve 34 is provided in the branch flow path 101a branched from the outward internal flow path 101. The branch flow path 101a is a flow path that connects between the on-off valve 42a and the second throttle valve 32 and between the first throttle valve 30 and the port A in the outgoing-side internal flow path 101. The check valve 34 is mounted in a direction that allows the flow of hydraulic oil in the reverse direction and blocks the flow in the forward direction.

  In this embodiment, the downstream side of the on-off valve 42 (closing / communication means), which is a pilot check valve, of the outgoing-side branch flow path 26 is connected to the pilot port 58 of the on-off valve 50 (opening / closing means). When the pressure on the downstream side of the on-off valve 42 in the branch flow path 26 increases, the on-off valve 50 (opening / closing means) opens.

  That is, the pressure of the pilot port 58 of the on-off valve 50 (opening / closing means) communicating with the downstream side of the on-off valve 42 of the outgoing-side branch flow path 26 increases, and the opening means 55 of the on-off valve 50 causes the urging force of the opening spring 82. 5 from the position shown in FIG. 4 to the position shown in FIG. As a result, the introduction port 56 and the discharge port 57 of the on-off valve 50 communicate with each other.

In the present embodiment, as shown in FIG. 2, an impact pressure bypass circuit is provided between the outgoing side branch flow path 26 (outgoing side internal flow path 101) and the return side branch flow path 27 (return side internal flow path 102). 37 (impact pressure bypass means or impact pressure bypass flow path) is provided.
The impact pressure bypass circuit 37 includes a forward / return direction bypass flow path 38 for releasing pressure to the return side flow path 27 when the pressure in the forward flow path 26 becomes excessive, It is constituted by a return / forward direction bypass flow path 40 which releases the pressure to the forward side branch flow path 26 when the pressure becomes excessive.
In each case, the relief valves 47 and 48 are interposed in the flow path, and when the pressure in the forward branch flow path 26 becomes excessive, the relief valve 47 of the forward / return direction bypass flow path 38 is opened. The pressure is released to the return-side branch flow path 27 side, and when the pressure in the return-side branch flow path 27 becomes excessive, the relief valve 48 of the return / forward direction bypass flow path 40 is opened to open the return-side branch flow path 26 side Relieve pressure.

Further, in the present embodiment, two circuits of discharge circuits 90 and 91 for discharging the internal leak of the turning hydraulic motor 5 are provided. One discharge circuit 90 connects the upstream part of the outgoing side branch flow path 26 and the downstream part of the return side branch flow path 27. The other discharge circuit 91 connects the downstream part of the outgoing side branch flow path 26 and the upstream part of the return side branch flow path 27.
Each of the discharge circuits 90 and 91 is a circuit in which the discharge sides of the check valves 92 and 93 are opposed to each other. The turning hydraulic motor 5 is connected between the discharge sides of the check valves 92 and 93 of the discharge circuit 91.
The discharge circuits 90 and 91 select and release the lowest pressure positions of the upstream part and the downstream part of the forward branch flow path 26 and the upstream part and the downstream part of the return branch flow path 27.

  The hydraulic circuit of the crusher 1 has the configuration described above.

Next, the operation of the crusher 1 of the present embodiment will be described.
In the present embodiment, opening and closing and turning of the crushing arms 3 can be performed by operating the switching valve 20.
The switching valve 20 employed in the present embodiment is a manual valve, and is a three-position four-way valve having three positions of a neutral, a parallel passage, and a cross passage. In the present embodiment, the switching valve 20 is of the manual type, but is not limited to the manual type.
In the circuit shown in FIG. 2, when the switching valve 20 is switched to the cross passage position, hydraulic oil is supplied to the bottom side 21 of the opening / closing hydraulic cylinder 10 to close the crushing arms 3 and 3, and the concrete pieces are separated by the crushing arms 3 and 3. Etc. can be crushed.

In the turning branch flow path 13, the pressure in the return-side branch flow path 27 increases. However, the turning branch flow path 13 has a relief valve 35, and the relief valve 35 functions as a check valve. Blocks directional flow. In addition, a check valve 33 is provided in the outgoing-side branch flow path 26 of the turning branch flow path 13, and the check valve 33 is provided in a direction for preventing the flow of the hydraulic oil in the reverse direction.
However, since the pressure is high between the switching valve 20 and the relief valve 35 in the return-side branch flow path 27 of the turning branch flow path 13, hydraulic oil is introduced into the opposing cavity 46 of the delay cylinder 36, The hydraulic oil in the hydraulic oil introduction cavity 45 for delay is discharged.

  On the other hand, in the circuit shown in FIG. 2, when the switching valve 20 is switched to the parallel passage position, the operating oil is supplied to the rod 22 side of the opening / closing hydraulic cylinder 10 and the crushing arms 3, 3 are opened. At this time, since the crushing arm opening operation of the crushing machine 1 has no load and the operating pressure is low, the pilot pressure applied to the on-off valve 42 of the combination valve 31 in the outgoing-side branch flow path 26 is low, and the on-off valve 42 is closed. Up to.

  When the crushing arms 3 and 3 reach full open and the supply pressure rises and the pressure of the hydraulic oil reaches or exceeds a predetermined pressure, the relief valve 43 of the combination valve 31 opens and pilot pressure is applied to the on-off valve 42, and the on-off valve 42 Opens. That is, the operating oil is supplied to the pilot port 58 of the on-off valve 42, and the on-off valve 42 is opened.

As a result, the introduction port 56 and the discharge port 57 of the on-off valve 42 communicate with each other, and the hydraulic oil passes through the on-off valve 42 in the forward direction (forward direction).
Here, the hydraulic oil flows preferentially to the delay hydraulic oil introduction cavity 45 of the delay cylinder 36, and after the piston of the delay cylinder 36 is completely extended and the delay hydraulic oil introduction cavity 45 is full, the hydraulic motor Hydraulic oil is supplied to the fifth side. Therefore, immediately after the hydraulic oil flows out of the combination valve 31, the hydraulic oil does not flow to the hydraulic motor 5, and the hydraulic motor 5 is prevented from rotating immediately.

Further, when the delay hydraulic oil introduction cavity 45 of the delay cylinder 36 is filled with hydraulic oil, the pressure on the downstream side of the on-off valve 42 increases, and the pressure on the downstream side of the on-off valve 42 is provided in the return-side branch flow path 27. 4, the valve body 52 of the on-off valve 50 shown in FIG. 4 is pressed by the opening means 55 and moves against the pressing means 53, and the valve seat 61 is opened. That is, the opening means 55 separates the valve body 52 from the valve seat 61 using the pilot pressure. For this reason, the on-off valve 50 is opened, and the turning branch flow path 13 is opened in the forward direction (return direction).
That is, between the introduction port 56 and the discharge port 57, the through hole 78 of the valve body side holding member 75, the space 79, the concave portion 65 of the valve body 52, the communication hole 52b, the annular space 79a, and the small diameter hole of the main body 51. The space 69 communicates.
As a result, the hydraulic oil is supplied to the hydraulic motor 5, and the hydraulic motor 5 rotates to rotate the crushing arms 3, 3 of the crusher 1.

  After turning the crushing arms 3 and 3 to a predetermined angle, the switching valve 20 is returned to the neutral position, the supply of hydraulic oil is shut off, and the turning of the crushing arms 3 and 3 is stopped. Next, a work vehicle (not shown) is operated to allow the crushing arms 3 and 3 of the crusher 1 to enter the portion to be dismantled, and then the switching valve 20 is switched to the cross passage position. As a result, the hydraulic oil is supplied from the switching valve 20 to the bottom side 21 of the opening / closing hydraulic cylinder 10, and the crushing arms 3, 3 are closed to perform the crushing operation.

In the crusher 1 of the present embodiment, when the crushing arms 3 and 3 are opened to reach the limit and the arm opening side flow path 23 has a high pressure higher than a predetermined value, the pressure on the upstream side of the combination valve 31 increases and the combination valve 31 (The on-off valve 42 serving as a closing / communicating means) is opened, and hydraulic oil flows downstream of the on-off valve 42.
The hydraulic oil flows preferentially into the delay hydraulic oil introduction cavity 45 of the delay cylinder 36, and it takes a while for the pressure to rise downstream of the on-off valve 42.
When the delay hydraulic oil introduction cavity 45 of the delay cylinder 36 becomes full, the pressure on the downstream side of the combination valve 31 rises, and in response to this pressure, the pressure of the pilot port 58 of the on-off valve 50 rises to open the on-off valve 50. .
Further, the pressure in the return-side branch flow path 27 increases, and the relief valve 35 opens. As a result, the hydraulic oil passes through the hydraulic motor 5 and the hydraulic motor 5 rotates. Here, a relief valve 35 is provided downstream of the hydraulic motor 5, and a constant back pressure is secured downstream of the hydraulic motor 5, so that the hydraulic motor 5 does not suddenly rotate.

  In the prior art, when hydraulic oil leaks downstream of the hydraulic motor and an external force is applied to the crushing arm during crushing work, the hydraulic motor idles and the crushing arm turns excessively. was there. On the other hand, according to the present embodiment, since the opening / closing valve 50 (opening / closing means) is provided in the return-side branch flow path 27, hydraulic oil is secured downstream of the hydraulic motor 5, and the hydraulic motor 5 runs idle. The crushing arms 3 and 3 do not pivot excessively.

  When the hydraulic motor 5 is stopped, an abnormally high impact pressure may act in the circuit, or a large torsion force may act on the crusher 1 during the crushing operation, resulting in an excessive load. That is, when performing the turning, an excessive load (shock external force) acts on the crusher 1. In this case, the impact pressure bypass circuit 37 operates to release the abnormally high pressure to the low pressure side. The impulse pressure bypass circuit 37 is configured so that, regardless of which port of the hydraulic motor 5 becomes high pressure, one of the relief valves 47 and 48 is relieved from the high pressure port side to the low pressure port side. Devices such as the hydraulic motor 5 can be protected from any high pressure.

  When hydraulic oil leaks in the hydraulic motor 5, the hydraulic oil is collected via the discharge circuits 90 and 91. That is, when a leak (hydraulic oil leakage) occurs in the turning hydraulic motor 5, the discharge circuits 90 and 91 provide a pair of ports (a hydraulic oil introduction side port A and a hydraulic oil discharge side port) through which hydraulic oil enters and exits. B and the hydraulic oil supply side port C and the hydraulic oil return side port D) are short-circuited.

  In the present embodiment, the crusher has been described as an attachment, but the present invention can be similarly applied to other attachments such as a gripper having a working arm, a cutting machine, and the like.

  In the present embodiment, a single hydraulically operated valve 100 for a crusher (a hydraulically operated valve for attachment of a working machine) is incorporated in a hydraulic circuit between the switching valve 20 and the hydraulic motor 5 for turning. That is, the circuit within the two-dot chain line in FIG. 2 is the hydraulically operated valve 100 for the crusher. FIG. 3 illustrates the circuit (the hydraulically actuated valve 100 for the crusher) within the two-dot chain line in FIG. FIG. 10 shows the appearance of a hydraulically operated valve 100 for a crusher.

As shown in FIGS. 2, 3, and 10, the hydraulic operating valve 100 for the crusher includes a hydraulic oil introduction port A, a hydraulic oil discharge port B, a hydraulic oil supply port C, and a hydraulic oil return port. D and cylinder ports E and F (delay cylinder ports). The cylinder ports E and F are ports that can communicate with the outside of the crusher hydraulically operated valve 100.
The hydraulic operating valve 100 for the crusher has an internal flow path 101 (an internal flow path) connecting the hydraulic oil introduction side port A and the hydraulic oil supply side port C therein, a hydraulic oil discharge side port B, and a hydraulic oil. There is a return-side internal flow path 102 (return-side flow path) connecting the return-side port D. That is, hydraulic oil introduction ports A and C are provided on both sides of the outward internal flow path 101, and hydraulic oil discharge ports B and D are provided on both sides of the return internal flow path 102.
The outgoing-side internal flow path 101 functions as a part of the outgoing-side branch flow path 26, and the first throttle valve 30 is combined in order from the hydraulic oil introduction side port A side to the hydraulic oil supply side port C side. A valve 31, a second throttle valve 32, and a check valve 33 are interposed. A check valve 34 is provided in parallel with the combination valve 31.

  The return-side internal flow path 102 functions as a part of the return-side branch flow path 27, and sequentially includes the on-off valve 50 and the relief valve (back pressure) from the hydraulic oil return port D to the hydraulic oil discharge port B. Generating means) 35 is interposed.

The outgoing-side internal flow path 101 has a branched flow path downstream of the combination valve 31, and the flow path is open to a port E for a cylinder.
The port F for the cylinder is connected between the relief valve 35 of the return-side internal flow path 102 and the port B on the hydraulic oil discharge side, and can communicate with the outside.

  The hydraulic oil introduction side port A and the hydraulic oil discharge side port B of the crusher hydraulic operation valve 100 are connected to the switching valve 20 (FIG. 2). Specifically, the hydraulic oil introduction side port A and the switching valve 20 are connected via the arm opening side flow path 23 and the outgoing side branch flow path 26, and the hydraulic oil discharge side port B and the switching valve 20 The arm closing side flow path 25 and the return side branch flow path 27 are connected to each other. In the example shown in FIG. 2, nothing is provided between the hydraulic oil introduction port A and the switching valve 20 and / or between the hydraulic oil discharge port B and the switching valve 20. The port A and the hydraulic oil discharge side port B do not necessarily have to be directly connected to the switching valve 20, but may be indirectly connected to the switching valve 20 via another configuration (not shown).

The hydraulic oil supply port C and hydraulic oil return port D are connected to the turning hydraulic motor 5 (FIG. 2). That is, the hydraulic oil supply-side port C and the hydraulic oil return-side port D are connected to the turning hydraulic motor 5 directly or indirectly by piping.
The delay cylinder ports E and F that can communicate with the outside of the crusher hydraulic valve 100 are connected to the delay cylinder 36 (FIG. 2). That is, the delay cylinder ports E and F are connected to the delay cylinder 36 directly or indirectly by piping.

  Here, it is preferable that the hydraulically actuated valve 100 for the crusher is constituted as one independent unit as shown in FIG. The hydraulic valve 100 for a crusher shown in FIG. 10 has a hydraulic circuit provided in a housing. That is, the impact pressure bypass circuit 37 (impact pressure bypass means), the opening / closing valve 42 (closing / communication means), the relief valve 35 (back pressure generating means), and the opening / closing valve 50 (opening / closing means) shown in FIG. It is preferable to connect the external piping to each of the ports A to F exposed on the surface of the housing (unitized) and configure the hydraulic circuit shown in FIG. In the example shown in FIG. 2, the cavities 45 and 46 of the delay cylinder 36 (regions on both sides of the piston 44) communicate with the ports E and F of the crusher hydraulically operated valve 100. That is, the delay cylinder 36 can be connected to the ports E and F.

  The hydraulically actuated valve 100 for a crusher according to the present embodiment can be easily mounted on the crusher 1, and piping work for the crusher 1 is greatly simplified.

With the hydraulically actuated valve for crusher 100 (the hydraulically actuated valve for attachment of the working machine) according to the present embodiment, it is possible to secure the operating oil in the return-side branch flow path 27 during the abutment operation.
In the crusher 1 (attachment) according to the present embodiment, unexpected turning of the crushing arms 3, 3 (working arm) during the turning operation can be prevented or suppressed.

Next, a hydraulically operated valve for a crusher 200 (a hydraulically operated valve for attachment of a working machine) according to another embodiment will be described with reference to FIG. In the hydraulically actuated valve for crusher 200, the same components as those of the hydraulically actuated valve for crusher 100 are denoted by the same reference numerals, and redundant description is omitted.
The hydraulically operated valve 200 for the crusher has ports A to F, like the hydraulically operated valve 100 for the crusher, and is installed between the switching valve 20 and the turning hydraulic motor 5.

In the crusher hydraulically operated valve 200, an on-off valve 42a (closing / communication means) and a pilot relief valve 95 are used instead of the combination valve 31 of the crusher hydraulically operated valve 100.
The on-off valve 42a is provided on the outgoing-side internal flow path 101 (flow path between port A and port C). The detailed structure of the on-off valve 42a will be described later.
The check valve 34 is provided in a branch flow path 101a branched from the outward internal flow path 101. The branch flow path 101a is a flow path that connects between the on-off valve 42a and the second throttle valve 32 and between the first throttle valve 30 and the port A in the outgoing-side internal flow path 101.
The pilot relief valve 95 is on a pipe 103 that connects the pilot port 580 of the on-off valve 42a to the downstream side (forward direction) of the relief valve 35 in the return-side internal flow path 102 (flow path between port B and port D). It is provided in.

  That is, in the hydraulically operated valve for crusher 200, a pilot relief valve 95 is provided instead of the relief valve 43 and the check valve 67 of the hydraulically operated valve for crusher 100. The hydraulically actuated valve for crusher 200 operates in the same manner as the hydraulically actuated valve for crusher 100, and can control the operation of the crushing arms 3, 3 (FIG. 1).

  Hereinafter, the structure of the on-off valve 42a will be described.

  As shown in FIGS. 9A and 9B, the on-off valve 42a has a valve body 520 and a pressing means 530 (closing spring) built in a tubular (tubular) main body 510.

As shown in FIGS. 9A and 9B, the main body 510 has a penetrated tubular structure. That is, main body 510 has space 780 therein.
One end of the main body 510 forms a relatively large-diameter opening, and a screw 960 (female screw) is formed on the inner peripheral surface. The other end of the main body 510 has an inward flange portion 600, and a relatively small hole 570 is provided in the center of the inward flange portion 600. A valve-side sealing member 750 is screwed and attached to the screw 960 of the main body 510. That is, one end of the main body 510 is closed by the valve body side sealing member 750. Although not shown, an oil-sealing process is performed between the main body 510 and the valve-side sealing member 750 (a portion other than the screw 960) with an O-ring (not shown) interposed therebetween. The hole 570 at the other end of the main body 510 functions as a discharge port 570. An inner edge of the discharge port 570 (hole 570) forms a valve seat 610. The discharge port 570 communicates with the space 780.

  In the side wall of the main body 510, holes 560 and 580 for communicating the space 780 with the outside are provided at two places separated in the longitudinal direction of the cylinder. The hole 560 is provided near the discharge port 570, and the hole 560 functions as the introduction port 560. The hole 580 is provided in the vicinity of the valve element-side sealing member 750 and functions as a pilot port 580.

  The valve element 520 has a substantially cylindrical outer shape, and has a large outer diameter portion 520a and a small outer diameter portion 520b. That is, the outer shape of the valve element 520 has a shape in which a large outer diameter portion 520a having a large outer diameter and a small outer diameter portion 520b having a small outer diameter are coaxially continuous. The outer diameter of the large diameter portion substantially matches the inner diameter of the main body 510, and the length of the valve body 520 is shorter than the interval between the valve body side sealing member 750 and the inward flange portion 600. Therefore, the valve body 520 can reciprocate along the main body 510 in the space 780 of the main body 510.

  The valve body 520 has a space formed by the concave portion 650 inside. The concave portion 650 has an open end on the large outer diameter portion 520a side and a closed end on the small outer diameter portion 520b side. Further, a communication hole 521 that allows the recess 650 to communicate with the outside is formed in the small outer diameter portion 520b of the valve body 520. The inside diameter of the concave portion 650 is not uniform, and has a large inside diameter portion 650a and a small inside diameter portion 650b. That is, the concave portion 650 has a structure in which a large-diameter portion 650a having a large internal diameter and a small-diameter portion 650b having a small internal diameter are continuous.

  The connection between the large inner diameter portion 650a and the small inner diameter portion 650b forms a step 651. Further, a screw portion 652 is provided in the small inner diameter portion 650b. A fixed aperture 550 is attached to the screw portion 652. The fixed aperture 550 has an annular structure, and has a function of further narrowing the inner diameter of the small inner diameter portion 650b (ie, a function of narrowing). By providing the fixed throttle 550, it is possible to cause a difference in the pressure of the working oil before and after the fixed throttle 550.

  Further, an annular edge of the end portion of the valve element 520 on the small outer diameter portion 520b side forms a tapered surface 620.

  When the valve body 520 is accommodated in the space 780 of the main body 510, an annular space 790 is formed between the inner wall of the main body 510 and the outer wall of the small outer diameter portion 520b of the valve body 520. That is, the space 790 is a part of the space 780 of the main body 510. The annular space 790 makes the introduction port 560 communicate with the communication hole 521. That is, the introduction port 560 communicates with the pilot port 580 via the space 790, the communication hole 521, the concave portion 650 (the small inner diameter portion 650 b and the large inner diameter portion 650 a), and the space 780.

  Pressing means 530 is provided between the step 651 and the valve-side sealing member 750. The pressing means 530 is a compression spring. That is, the valve body 520 is urged toward the discharge port 570 side by the pressing means 530, and the tapered surface 620 is in contact with (seats) the valve seat 610 of the discharge port 570. When the valve body 520 is seated (closed) on the valve seat 610, the discharge port 570 is closed, the discharge port 570 and the introduction port 560 are shut off, and when the valve body 520 separates from the valve seat 610 (opens). , The discharge port 570 and the introduction port 560 communicate with each other.

  When the crushing arms 3 and 3 reach the full open state and the supply pressure increases and the pressure of the hydraulic oil reaches a predetermined pressure or more, the pilot relief valve 95 opens, the pilot pressure is applied to the on-off valve 42a, and the on-off valve 42a opens.

  Specifically, as shown in FIG. 9A, the introduction port 560 and the pilot port 580 are formed by the annular space 790, the communication hole 521 of the valve body 520, the concave portion 650 (the small inner diameter portion 650b, the fixed throttle 550, and the large throttle 550). When the pressure on the upstream side of the on-off valve 42a rises and exceeds a certain value, the pilot relief valve 95 (FIG. 8) is opened to open the space of the on-off valve 42a. A pressure difference is generated between 790 and the space 780 (before and after the valve element 520), and the valve element 520 moves to the valve element-side sealing member 750 side, the check mechanism is released, and hydraulic oil flows in both directions. Can be done.

  When the pilot relief valve 95 is opened, a pressure difference is generated between the space 790 and the space 780 (before and after the valve body 520) of the on-off valve 42a shown in FIG. The pressure member 750 moves to the pressure member 750 side, and moves from the position shown in FIG. 9A to the position shown in FIG. 9B against the urging force of the closing spring 530 (pressing means), and the valve body 520 is moved to the valve seat. Open the valve away from 610. As a result, the introduction port 560 and the discharge port 570 of the on-off valve 42a communicate. Then, the hydraulic oil flows through the on-off valve 42a in the forward direction (forward direction).

  In the present embodiment, the hydraulically actuated valves for the crusher have been described as the hydraulically actuated valves for the attachment of the working machine, but the hydraulically actuated valves for other attachments having a working arm such as a gripper, a cutting machine, and a shaker are described. It is also possible to carry out.

1 Crusher (attachment)
3 crushing arm (work arm)
5 Hydraulic motor for swing 6 Swivel mechanism 10 Hydraulic cylinder for opening and closing (Hydraulic actuator for opening and closing; drive cylinder)
DESCRIPTION OF SYMBOLS 11 Basic piping 12 Opening / closing hydraulic flow path 13 Turning branch flow path 20 Switching valve (switching means)
23 Arm open side flow path 25 Arm closed side flow path 26 Outgoing side branch flow path 27 Return side branch flow path 31 Combination valve 35 Relief valve (back pressure generating means)
36 Delay cylinder 37 Impact pressure bypass circuit 42, 42a Open / close valve (closing / communicating means)
44 Delay cylinder piston 45, 46 Cavity (area on both sides of delay cylinder piston)
50 opening / closing valve (opening / closing means)
52 Valve body 53 Pressing means 55 Opening means 58 Pilot port 61 Valve seat 75 Valve body side holding member 81 Space 90, 91 Shock absorbing circuit 100, 200 Hydraulically operated valve for crusher (Hydraulically operated valve for attachment of work machine)
101 Outgoing side internal flow path (going side flow path)
102 Return side internal flow path (return side flow path)
A Hydraulic oil introduction side port B Hydraulic oil discharge side port C Hydraulic oil supply side port D Hydraulic oil return side port E Delay cylinder port F Delay cylinder port

Claims (8)

An attachment of a work machine attached to the work machine,
A work arm that is opened and closed by an opening / closing hydraulic actuator, a turning mechanism that is driven by a turning hydraulic motor to turn the work arm, and a switching unit that switches a flow direction of hydraulic oil supplied to the opening / closing hydraulic actuator; An opening / closing hydraulic flow path that communicates the switching means with the opening / closing hydraulic actuator, and the turning hydraulic path that branches from a side that is a hydraulic oil supply side when the working arm is in an open state. A forward branch flow path that communicates with the hydraulic motor, and a return branch flow path that returns the operating oil that has passed through the hydraulic motor for rotation through the hydraulic motor for rotation and the switching means;
The outgoing-side branch flow path or the return-side branch flow path is provided with a closing / communicating means that is normally closed and communicates when a predetermined pressure or more is reached. When the pressure applied to the working machine reaches a predetermined pressure or more, the closing / communication means communicates, hydraulic fluid is supplied to the turning hydraulic motor, and the turning hydraulic motor operates.
The return-side branch channel has an opening / closing unit and a back pressure generating unit,
The opening / closing means has a valve seat having an opening, a valve body for sealing the valve seat, a pressing means for pressing the valve body toward the valve seat, and an opening means for separating the valve body from the valve seat. A hydraulic fluid that flows in a direction to press the valve body against the valve seat.   The attachment of a work machine according to claim 1, wherein the opening / closing means is a pilot check valve, and the opening means separates the valve body from the valve seat using pilot pressure.   The working machine according to claim 2, wherein the outgoing-side branch flow path is connected to a pilot port of the opening / closing means, and the valve body is separated from the valve seat when the pressure in the outgoing-side branch flow path becomes equal to or higher than a predetermined value. Attachment.   The attachment of a working machine according to any one of claims 1 to 3, wherein the back pressure generating means is a relief valve, and is provided closer to the switching means than the opening / closing means. The turning hydraulic motor has a pair of ports through which hydraulic oil enters and exits.
A shock pressure bypass means for short-circuiting the pair of ports when a shocking external force is applied to the turning hydraulic motor,
The attachment for a working machine according to any one of claims 1 to 4, wherein the impact pressure bypass unit, the closing / communicating unit, the back pressure generating unit, and the opening / closing unit are integrated. . A hydraulically operated valve for attachment of a work machine,
It has an outgoing side flow path (outgoing side internal flow path) and a return side flow path (return side internal flow path),
At both ends of the outward flow path, there are a hydraulic oil introduction side port A and a hydraulic oil supply side port C,
At both ends of the return flow path, a hydraulic oil discharge port B and a hydraulic oil return port D are provided,
A closing / communication valve that is normally closed and communicates when the pressure reaches a predetermined pressure or more, and a forward-side check that allows a flow toward the hydraulic oil supply port C and prevents the reverse flow. A flow path between the closing / communicating valve and the hydraulic oil supply side port C communicates with a port E that can communicate with the outside;
The return-side internal flow path has an on-off valve, and a back-pressure generating valve on the hydraulic oil discharge side port B side.
The on-off valve is a pilot check valve, a valve seat having an opening, a valve body for sealing the valve seat, pressing means for pressing the valve body toward the valve seat, and a valve body. It has opening means for separating from the valve seat, and the hydraulic oil flows in a direction to press the valve body against the valve seat,
A flow path between the back pressure generating valve and the hydraulic oil discharge side port B communicates with a port F that can communicate with the outside,
It further has an impact pressure bypass passage, which short-circuits the pair of ports C and D when an impact external force is applied to the hydraulic oil supply side port C or the hydraulic oil return side port D. A hydraulically operated valve for an attachment of a working machine, wherein A work arm driven to be opened and closed by a drive cylinder, a turning mechanism driven by a turning hydraulic motor to turn the work arm, and an attachment provided with a switching valve for opening and closing the working arm, the switching valve and the turning Hydraulic valve for attachment connecting between hydraulic motors for
A hydraulic oil introduction side port A connected to the switching valve, a hydraulic oil discharge side port B, a hydraulic oil supply side port C connected to the turning hydraulic motor, and a hydraulic oil return side port D;
An internal flow passage connecting the hydraulic oil introduction side port A and the hydraulic oil supply side port C therein, and a return internal flow path connecting the hydraulic oil discharge side port B and the hydraulic oil return side port D therein;
A closing / communication valve that is normally closed and communicates when the pressure reaches a predetermined pressure or more, and a forward-side check that allows a flow toward the hydraulic oil supply port C and prevents the reverse flow. A flow path between the closing / communicating valve and the hydraulic oil supply side port C communicates with a port E that can communicate with the outside;
The return-side internal flow path has an on-off valve, and a back-pressure generating valve on the hydraulic oil discharge side port B side.
The on-off valve is a pilot check valve, a valve seat having an opening, a valve body for sealing the valve seat, pressing means for pressing the valve body toward the valve seat, and a valve body. It has opening means for separating from the valve seat, and the hydraulic oil flows in a direction to press the valve body against the valve seat,
A flow path between the back pressure generating valve and the hydraulic oil discharge side port B communicates with a port F that can communicate with the outside,
It further has an impact pressure bypass passage, which short-circuits the pair of ports C and D when an impact external force is applied to the hydraulic oil supply side port C or the hydraulic oil return side port D. A hydraulically operated valve for an attachment of a working machine, wherein Having a delay cylinder with a piston movable inside,
8. The hydraulically actuated valve for an attachment of a working machine according to claim 6, wherein each of the ports E and F communicates with a region on both sides of a piston in the delay cylinder. 9.

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