JP4837528B2 - Hydraulic circuit of hydraulic equipment - Google Patents

Description

  The present invention relates to a hydraulic circuit of a hydraulic device in which a hydraulic actuator operates with expansion and contraction.

In some hydraulic devices, hydraulic actuators operate by expanding and contracting. The hydraulic oil is supplied from the hydraulic oil pump to one oil chamber of the hydraulic actuator, and the hydraulic oil is discharged from the other oil chamber of the hydraulic actuator to the hydraulic oil tank, so that the hydraulic actuator expands and contracts.
For example, a hydraulic crusher opens and closes a crushing arm to crush an object to be crushed, and the crushing arm is opened and closed by a hydraulic actuator. For example, when the hydraulic actuator is reduced, the crushing arm is opened, and when the hydraulic actuator is extended, the crushing arm is closed.

  The operating speed of the hydraulic equipment using the hydraulic actuator is determined by the extension speed and the reduction speed of the hydraulic actuator. In order to increase the operating speed of hydraulic equipment, a hydraulic circuit incorporating a pressure increasing valve has been proposed (see, for example, Patent Document 1). In a hydraulic crusher equipped with this hydraulic circuit, the hydraulic actuator is a small diameter, high pressure cylinder. Since the hydraulic actuator has a small diameter, the pressure receiving area of the hydraulic actuator is reduced, and the extension speed and reduction speed of the hydraulic actuator are increased. That is, in the crusher, the operation speed when the crushing arm is opened and closed is increased. At the time of crushing, a high pressure acts on the hydraulic actuator, and a crushing force similar to that of a large-diameter hydraulic actuator can be obtained.

Further, as another hydraulic circuit for increasing the operating speed of the hydraulic equipment, a hydraulic circuit incorporating a speed increasing valve has been proposed (for example, see Patent Document 2). In a hydraulic crusher equipped with this hydraulic circuit, a so-called differential circuit is formed. When the differential circuit communicates, the hydraulic oil discharged from the reduction side oil chamber of the hydraulic actuator flows into the extension side oil chamber, the amount of hydraulic oil flowing into the extension side oil chamber increases, and the extension speed of the hydraulic actuator increases. . Therefore, in the hydraulic crusher in which the hydraulic actuator is extended and the crushing arm is closed, the extension speed of the hydraulic actuator is increased, and the operating speed when the crushing arm is closed is increased.
JP-A-7-248003 Japanese Utility Model Publication No. 6-43155

  However, when a hydraulic circuit incorporating the above-described pressure increasing valve is mounted on a hydraulic crusher, there is a problem that the response time from the crushing arm adding the material to be crushed to crushing is delayed. That is, after the crushing arm temporarily holds the object to be crushed, it takes time for the pressure of the hydraulic actuator to be increased to a predetermined operating pressure by the operation of the pressure increasing valve, and this pressure increase time delays the response time. Further, since the high pressure acts on the hydraulic circuit, the durability of the seal in the pressure increasing valve and the hydraulic actuator is lowered.

When the hydraulic circuit incorporating the above speed increasing valve is mounted on a hydraulic crusher, the operating pressure of the hydraulic actuator increases instantaneously when the crushing arm pinches the object to be crushed. Therefore, the response time from when the crushing arm holds the object to be crushed until it is crushed is short. In addition, the hydraulic actuator need not be a high-pressure cylinder, and it is possible to prevent a decrease in the durability of the seal. However, this hydraulic circuit only speeds up the extension speed of the hydraulic actuator. Therefore, the reduction speed cannot be increased, and the operation speed when the crushing arm is opened cannot be increased.
The present invention solves the above problems, and an object of the present invention is to provide a hydraulic circuit of a hydraulic device that can increase the operating speed when the hydraulic actuator is reduced.

  The present invention adopts the following configuration in order to solve the problem. The hydraulic circuit of the hydraulic device according to the invention of claim 1 includes a hydraulic actuator that operates the hydraulic device by expanding and contracting, a reduction-side oil passage that is connected from the control valve to the reduction-side oil chamber of the hydraulic actuator, and a control valve A hydraulic circuit of a hydraulic device having an extension side oil passage connected to an extension side oil chamber of a hydraulic actuator, wherein the second accumulator oil is connected to the extension side oil passage by a first accumulator oil passage. An accumulator connected to the reduction-side oil passage by the passage, a pilot check valve that is installed in the first accumulator oil passage and that opens when hydraulic fluid flows from the reduction-side oil passage to the reduction-side oil chamber, and a first accumulator oil A check valve that is installed in the passage and flows hydraulic oil from the extension side oil passage to the accumulator, and a reduction side oil chamber that is installed in the second accumulator oil passage A reverse pilot check valve which opens when al reduction side oil passage in the hydraulic oil flows, a.

  When the control valve is operated to supply hydraulic oil from the reduction side oil passage to the reduction side oil chamber of the hydraulic actuator, and the hydraulic oil is discharged from the extension side oil chamber of the actuator to the extension side oil passage, the hydraulic actuator is reduced. The reduction side oil passage that supplies hydraulic oil to the reduction side oil chamber is high pressure, and the extension side oil passage that discharges hydraulic oil from the extension side oil chamber is low pressure. Therefore, the pilot check valve of the first accumulator oil passage is Open and the reverse pilot check valve of the second accumulator oil passage closes. When the pilot check valve is opened, the hydraulic oil discharged from the extension side oil chamber flows from the extension side oil passage through the first accumulator oil passage to the accumulator and also to the hydraulic oil tank. Accordingly, since the hydraulic oil discharge path increases and the pressure also decreases, the pressure of the hydraulic oil flowing into the reduction-side oil path decreases, and accordingly, the pump discharge amount increases, resulting in an increase in the reduction speed of the hydraulic actuator.

  When the control valve is operated, hydraulic fluid is supplied from the extension side oil passage to the extension side oil chamber of the hydraulic actuator and discharged from the reduction side oil chamber of the actuator to the reduction side oil passage, the hydraulic actuator extends. Since the extension side oil passage for supplying hydraulic oil to the extension side oil chamber is high pressure and the reduction side oil passage for discharging hydraulic oil from the reduction side oil chamber is low pressure, the pilot check valve of the first accumulator oil passage is Closes and the reverse pilot check valve of the second accumulator oil passage opens. When the reverse pilot check valve is opened, the hydraulic oil in the accumulator is discharged to the reduction side oil passage through the second accumulator oil passage.

  A hydraulic circuit of a hydraulic device according to a second aspect of the invention is the hydraulic circuit of the hydraulic device according to the first aspect, wherein the hydraulic circuit is reduced by a differential circuit that communicates when hydraulic fluid flows from the extension side oil passage to the extension side oil chamber. A speed increasing valve that allows hydraulic oil to flow from the side oil path to the extension side oil path to increase the extension speed of the hydraulic actuator is installed between the control valve and the hydraulic actuator. A first accumulator oil passage that branches from the extension side oil passage and a second accumulator oil passage that branches from the reduction side oil passage between the speed increasing valve and the control valve are connected to the accumulator.

  When hydraulic oil flows from the extension side oil passage to the extension side oil chamber, the differential circuit communicates, and the hydraulic oil in the reduction side oil chamber flows from the reduction side oil passage through the extension side oil passage to the extension side oil chamber, The amount of hydraulic oil flowing into the extension side oil chamber increases, and the extension speed of the hydraulic actuator increases. A differential circuit is formed by the speed increasing valve, and it is not necessary to reduce the diameter of the hydraulic actuator to a high pressure compatible cylinder.

  A hydraulic circuit of a hydraulic device according to a third aspect of the invention includes a hydraulic actuator that operates the hydraulic device by expanding and contracting, a reduction-side oil passage that is connected from the control valve to a reduction-side oil chamber of the hydraulic actuator, and a control valve A hydraulic circuit of a hydraulic device having an extension side oil passage connected to an extension side oil chamber of a hydraulic actuator, and reduced by a differential circuit communicating when hydraulic oil flows from the extension side oil passage to the extension side oil chamber A speed increasing valve is installed between the control valve and the hydraulic actuator to increase the extension speed of the hydraulic actuator by flowing hydraulic oil from the side oil path to the extension side oil path. A first accumulator oil passage branched from the expansion side oil passage and a second accumulator oil passage branched from the reduction side oil passage between the speed increasing valve and the hydraulic actuator. When the hydraulic fluid flows from the reduction side oil passage to the reduction side oil chamber, the pilot control valve causes the first accumulator oil passage to communicate with the accumulator and the second accumulator. When the accumulator oil passage is closed, the hydraulic oil that flows from the extension side oil chamber to the extension side oil passage flows into the accumulator, and when the hydraulic oil flows from the extension side oil passage to the extension side oil chamber, the pilot control valve The accumulator oil passage closes, and the second accumulator oil passage communicates with the accumulator, so that the hydraulic oil flows from the accumulator to the reduced-side oil passage.

  When the control valve is operated to supply hydraulic oil from the reduction side oil passage to the reduction side oil chamber of the hydraulic actuator, and the hydraulic oil is discharged from the extension side oil chamber of the actuator to the extension side oil passage, the hydraulic actuator is reduced. At this time, the first accumulator oil passage is communicated by the pilot control valve, and the second accumulator oil passage is closed. The hydraulic oil that has flowed from the extension side oil chamber to the extension side oil passage flows to the hydraulic oil tank and also flows to the accumulator. Accordingly, since the hydraulic oil discharge path increases and the pressure also decreases, the pressure of the hydraulic oil flowing into the reduction-side oil path decreases, and accordingly, the pump discharge amount increases, resulting in an increase in the reduction speed of the hydraulic actuator.

  When the control valve is operated, hydraulic fluid is supplied from the extension side oil passage to the extension side oil chamber of the hydraulic actuator and discharged from the reduction side oil chamber of the actuator to the reduction side oil passage, the hydraulic actuator extends. At this time, the first accumulator oil passage is closed by the pilot control valve, and the second accumulator oil passage communicates. The hydraulic fluid of the accumulator is discharged to the reduction side oil passage through the second accumulator oil passage. In addition, the differential circuit communicates so that not only the hydraulic fluid discharged from the reduction side oil chamber to the reduction side oil passage, but also the hydraulic fluid of the accumulator flows from the reduction side oil passage to the extension side oil passage. The elongation speed is further increased.

  Since the hydraulic circuit of the hydraulic device according to the present invention has the above-described configuration, the operating speed when the hydraulic actuator is reduced is increased.

A first embodiment for carrying out the present invention will be described with reference to FIGS. 1 to 3.
First, the configuration of the present embodiment will be described with reference to FIG.
The hydraulic actuator 1 is connected to a crushing arm (not shown) of a hydraulic crusher. The crushing arm is opened when the hydraulic actuator 1 is contracted, and the crushing arm is closed when the hydraulic actuator 1 is extended. FIG. 1 shows the state of the hydraulic circuit when the crushing arm is open.

  The hydraulic actuator 1 has a reduction side oil chamber 2 and an extension side oil chamber 3. A reduction side oil passage 5 is connected to the reduction side oil chamber 2 from a control valve 26 via a speed increasing valve 10. The extension side oil passage 6 is connected to the extension side oil chamber 3 from the control valve 26 via the speed increasing valve 10. The control valve 26 is connected to the hydraulic oil pump 15 and the hydraulic oil tank 16. By switching the control valve 26, one of the reduction side oil passage 5 and the extension side oil passage 6 is connected to the hydraulic oil pump 15. The other is configured to be connectable to the hydraulic oil tank 16.

  The speed increasing valve 10 includes a differential oil passage 11, a sequence valve 30, a check valve 31, and a reverse pilot check valve 34. When the sequence valve 30 is installed in the reduction side oil passage 5 and the reduction side oil passage 5 is connected to the hydraulic oil pump 15, the sequence valve 30 is opened by the discharge pressure of the hydraulic oil pump 15, and the reduction side oil passage 5. Is configured to communicate. Further, when the extension side oil passage 6 is connected to the hydraulic oil pump 15 and the pressure of the extension side oil passage 6 is increased to a predetermined pressure, the sequence valve 30 is opened by the discharge pressure of the hydraulic oil pump 15, and the reduction side oil is supplied. The path 5 is configured to communicate. Here, the “predetermined pressure” means that, in a state where the crushing arm of the hydraulic crusher clamps the object to be crushed, a load is applied to the actuator 1 so that the pressure of the extension side oil passage 6 is changed to the extension side oil passage. 6 is the pressure when the pressure is further increased from the state connected to the hydraulic oil pump 15.

  A differential oil passage 11 branches off from the reduction side oil passage 5 between the sequence valve 30 and the hydraulic actuator 1 and is connected to the extension side oil passage 6. A check valve 31 and a reverse pilot check valve 34 are installed in the differential oil passage 11, and both the check valve 31 and the reverse pilot check valve 34 flow hydraulic fluid from the reduction side oil passage 5 to the extension side oil passage 6. is there. The pressure of the reduction side oil passage 5 becomes the pilot pressure of the reverse pilot check valve 34. When the reduction side oil passage 5 is connected to the hydraulic oil tank 16 and becomes low pressure, the reverse pilot check valve 34 opens and the differential oil passage is opened. 11 communicates, and hydraulic oil flows from the reduction side oil passage 5 to the extension side oil passage 6 through the differential oil passage 11.

Between the speed increasing valve 10 and the control valve 26, the first accumulator oil passage 21 branches from the extension side oil passage 6, and the second accumulator oil passage 22 branches from the reduction side oil passage 5. The first accumulator oil passage 21 and the second accumulator oil passage 22 merge and are connected to the accumulator 20.
A pilot check valve 33 and a check valve 32 are installed in the first accumulator oil passage 21. The check valve 32 is in the direction in which the hydraulic oil flows from the extension side oil passage 6 to the accumulator 20, and the pilot check valve 33 is in the opposite direction to the check valve 32. The pressure in the reduction side oil passage 5 is the pilot pressure of the pilot check valve 33, and when the reduction side oil passage 5 is connected to the hydraulic oil pump 15, the discharge pressure of the hydraulic oil pump 15 causes the reduction side oil passage 5 to The pressure rises, the pilot check valve 33 opens, and the first accumulator oil passage 21 communicates.

A reverse pilot check valve 35 is installed in the second accumulator oil passage 22. The direction of the reverse pilot check valve 35 is a direction in which hydraulic fluid flows from the accumulator 20 to the reduction-side oil passage 5. When the pressure in the reduction side oil passage 5 becomes the pilot pressure of the reverse pilot check valve 35 and the reduction side oil passage 5 is connected to the hydraulic oil tank 16, the pressure in the reduction side oil passage 5 decreases, and the reverse pilot The check valve 35 is opened, and the second accumulator oil passage 22 is in communication.
The accumulator 20 is a low-pressure accumulator. When the first accumulator oil passage 21 communicates, the hydraulic oil discharged from the extension side oil chamber 3 to the extension side oil passage 6 can be sucked, and the second accumulator oil passage 22 When communicating, the hydraulic oil in the accumulator 20 is configured to be discharged to the reduction-side oil passage 5.

Next, the operation will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, when opening the crushing arm, the control valve 26 is operated to connect the hydraulic oil pump 15 and the reduction side oil passage 5, and connect the hydraulic oil tank 16 and the extension side oil passage 6. To do. The hydraulic oil is discharged from the hydraulic oil pump 15 to the reduction side oil passage 5, the pressure in the reduction side oil passage 5 rises, and the sequence valve 30 of the speed increasing valve 10 opens. Then, the hydraulic oil flows through the reduction side oil passage 5 and is supplied to the reduction side oil chamber 2, and at the same time, the hydraulic oil is discharged from the extension side oil chamber 3 to the extension side oil passage 6, and the hydraulic actuator 1 is reduced and crushed. The arm opens.

  During this time, the reverse pilot check valve 34 is closed and the differential oil passage 11 is closed. Further, the pilot check valve 33 is opened and the first accumulator oil passage 21 is communicated, and the reverse pilot check valve 35 is closed and the second accumulator oil passage 22 is closed. Accordingly, the hydraulic oil discharged from the extension side oil chamber 3 to the extension side oil passage 6 flows to both the accumulator 20 and the hydraulic oil tank 16. The reduction speed of the hydraulic actuator 1 increases as the accumulator 20 sucks the hydraulic oil, and the opening speed of the crushing arm increases.

FIG. 2 shows a state of the hydraulic circuit until the crushing arm starts to clamp the crushing object when the crushing arm is closed.
As shown in FIG. 2, when closing the crushing arm, the control valve 26 is operated to connect the hydraulic oil pump 15 and the expansion side oil passage 6, and connect the hydraulic oil tank 16 and the reduction side oil passage 5. To do. The hydraulic oil is discharged from the hydraulic oil pump 15 to the extension side oil passage 6 to increase the pressure of the extension side oil passage 6, and the hydraulic oil flows through the extension side oil passage 6 and is supplied to the extension side oil chamber 3, The hydraulic oil is discharged from the reduction-side oil chamber 2 to the reduction-side oil passage 5, the hydraulic actuator 1 is extended, and the crushing arm is closed.

During this time, the reverse pilot check valve 34 opens and the differential oil passage 11 communicates. Further, the pilot check valve 33 is closed and the first accumulator oil passage 21 is closed, and the reverse pilot check valve 35 is opened and the second accumulator oil passage 22 is communicated.
When the differential oil passage 11 communicates, the hydraulic oil discharged from the reduction side oil chamber 2 to the reduction side oil passage 5 flows into the extension side oil chamber 3 through the differential oil passage 11 and the extension side oil passage 6. Since the hydraulic oil in the reduction-side oil chamber 2 flows into the extension-side oil chamber 3, the amount of hydraulic oil flowing into the extension-side oil chamber 3 increases, the extension speed of the hydraulic actuator 1 increases, and the crushing arm has a high closing speed. Become.
Further, the hydraulic oil in the accumulator 20 is discharged from the second accumulator oil passage 22 to the reduction side oil passage 5 and then discharged from the extension side oil chamber 3 to the extension side oil passage 6 when the crushing arm is opened. The hydraulic oil can be sucked into the accumulator 20.

FIG. 3 shows a state of the hydraulic circuit while the crushing arm is closing the crushing object when the crushing arm is closed.
As shown in FIG. 3, when the crushing arm clamps the crushing target, a load is applied to the actuator 1, and the pressure of the extension side oil passage 6 further increases from the state until the crushing arm starts to clamp the crushing target. Then, the sequence valve 30 is opened by the discharge pressure of the hydraulic oil pump 15, and the reduction-side oil passage 5 is communicated.
During this time, the reverse pilot check valve 34 is closed and the differential oil passage 11 is closed, and the hydraulic oil discharged from the reduction-side oil chamber 2 to the reduction-side oil passage 5 flows into the hydraulic oil tank 16.

A second embodiment for carrying out the present invention will be described with reference to FIGS.
First, the configuration of the present embodiment will be described with reference to FIG.
The configuration of the hydraulic circuit in the present embodiment has the same configuration as that of the first embodiment except for the configuration of the accumulator 20, the first accumulator oil passage 21, and the second accumulator oil passage 22. FIG. 4 shows the state of the hydraulic circuit when the crushing arm is open.

  Between the speed increasing valve 10 and the hydraulic actuator 1, the first accumulator oil passage 21 branches from the expansion side oil passage 6, and the second accumulator oil passage 22 branches from the reduction side oil passage 5. The first accumulator oil passage 21 and the second accumulator oil passage 22 are connected to the accumulator 20 via a pilot control valve 27. The pressure in the reduction side oil passage 5 and the extension side oil passage 6 is the pilot pressure of the pilot control valve 27. When the reduction-side oil passage 5 is connected to the hydraulic oil pump 15, the pilot control valve 27 communicates with the accumulator 20, the second accumulator oil passage 22 is closed, and the extension-side oil is closed. When the path 6 is connected to the hydraulic oil pump 15, the first accumulator oil path 21 is closed, and the second accumulator oil path 22 communicates with the accumulator 20.

Next, the operation will be described with reference to FIGS.
As shown in FIG. 4, when opening the crushing arm, the control valve 26 is operated to connect the hydraulic oil pump 15 and the reduction side oil passage 5, and to connect the hydraulic oil tank 16 and the extension side oil passage 6. To do. Due to the discharge pressure of the hydraulic oil pump 15, the pressure in the reduction side oil passage 5 rises, and the sequence valve 30 of the speed increasing valve 10 opens. Then, the hydraulic oil flows through the reduction side oil passage 5 and is supplied to the reduction side oil chamber 2, and at the same time, the hydraulic oil is discharged from the extension side oil chamber 3 to the extension side oil passage 6, and the hydraulic actuator 1 is reduced and crushed. The arm opens.

  During this time, the reverse pilot check valve 34 is closed and the differential oil passage 11 is closed. Further, the first accumulator oil passage 21 is communicated with and connected to the accumulator 20 by the pilot control valve 27, and the second accumulator oil passage 22 is closed. Accordingly, the hydraulic oil discharged from the extension side oil chamber 3 to the extension side oil passage 6 flows to both the accumulator 20 and the hydraulic oil tank 16. The reduction speed of the hydraulic actuator 1 increases as the accumulator 20 sucks the hydraulic oil, and the opening speed of the crushing arm increases.

FIG. 5 shows a state of the hydraulic circuit until the crushing arm starts to clamp the crushing object when the crushing arm is closed.
As shown in FIG. 5, when closing the crushing arm, the control valve 26 is operated to connect the hydraulic oil pump 15 and the expansion side oil passage 6, and connect the hydraulic oil tank 16 and the reduction side oil passage 5. To do. Then, the hydraulic oil flows through the extension side oil passage 6 and is supplied to the extension side oil chamber 3, and at the same time, the hydraulic oil is discharged from the reduction side oil chamber 2 to the reduction side oil passage 5, and the hydraulic actuator 1 extends. The hydraulic actuator 1 is extended and the crushing arm is closed.
During this time, the reverse pilot check valve 34 opens and the differential oil passage 11 communicates. Further, the first accumulator oil passage 21 is closed by the pilot control valve 27, and the second accumulator oil passage 22 communicates with the accumulator 20.

The hydraulic oil in the accumulator 20 is discharged from the second accumulator oil passage 22 to the reduction side oil passage 5. The hydraulic oil discharged from the reduction side oil chamber 2 to the reduction side oil passage 5 and the hydraulic oil in the accumulator 20 flow into the extension side oil chamber 3 through the differential oil passage 11 and the extension side oil passage 6. . Since the hydraulic oil in the accumulator 20 flows into the extension-side oil chamber 3 together with the hydraulic oil in the reduction-side oil chamber 2, the amount of hydraulic oil flowing into the extension-side oil chamber 3 is further increased than in the first embodiment. The extension speed of the hydraulic actuator 1 is further increased, and the closing speed of the crushing arm is further increased.
Further, the hydraulic oil in the accumulator 20 is discharged from the second accumulator oil passage 22 to the reduction side oil passage 5 and then discharged from the extension side oil chamber 3 to the extension side oil passage 6 when the crushing arm is opened. The hydraulic oil can be sucked into the accumulator 20.

FIG. 6 shows a state of the hydraulic circuit while the crushing arm is closing the crushing object when the crushing arm is closed.
As shown in FIG. 6, when the crushing arm clamps the crushing target, a load is applied to the actuator 1, and the pressure of the extension side oil passage 6 further increases from the state until the crushing arm starts to clamp the crushing target. Then, the sequence valve 30 is opened by the discharge pressure of the hydraulic oil pump 15, and the reduction-side oil passage 5 is communicated.
During this time, the reverse pilot check valve 34 is closed and the differential oil passage 11 is closed, and the hydraulic oil discharged from the reduction-side oil chamber 2 to the reduction-side oil passage 5 flows into the hydraulic oil tank 16.

It is a lineblock diagram of the hydraulic circuit concerning a 1st embodiment, and is a figure showing the state of a hydraulic circuit at the time of crushing arm opening. It is a lineblock diagram of the hydraulic circuit concerning a 1st embodiment, and is a figure showing the state of a hydraulic circuit until a crushing arm begins to pinch a crushing object at the time of crushing arm closing. It is a block diagram of the hydraulic circuit which concerns on 1st Embodiment, and is a figure which shows the state of a hydraulic circuit while the crushing arm is pinching the crushing object at the time of crushing arm closing. It is a block diagram of the hydraulic circuit which concerns on 2nd Embodiment, and is a figure which shows the state of a hydraulic circuit at the time of crushing arm opening. It is a block diagram of the hydraulic circuit which concerns on 2nd Embodiment, and is a figure which shows the state of a hydraulic circuit until a crushing arm begins to pinch the crushing object at the time of crushing arm closing. It is a block diagram of the hydraulic circuit which concerns on 2nd Embodiment, and is a figure which shows the state of the hydraulic circuit while the crushing arm is pinching the crushing object at the time of crushing arm closing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic actuator 2 Reduction side oil chamber 3 Extension side oil chamber 5 Reduction side oil passage 6 Extension side oil passage 10 Speed increasing valve 11 Differential oil passage 15 Hydraulic oil pump 16 Hydraulic oil tank 20 Accumulator 21 First accumulator oil passage 22 Second accumulator oil passage 26 Control valve 27 Pilot control valve 30 Sequence valve 31, 32 Check valve 33 Pilot check valve 34, 35 Reverse pilot check valve

Claims (3)

A hydraulic actuator that operates the hydraulic device by expanding and contracting, a reduction side oil passage connected from the control valve to the reduction side oil chamber of the hydraulic actuator, and an extension side oil connected from the control valve to the extension side oil chamber of the hydraulic actuator A hydraulic circuit of a hydraulic device having a path,
An accumulator connected to the expansion side oil passage by the first accumulator oil passage and connected to the reduction side oil passage by the second accumulator oil passage;
A pilot check valve installed in the first accumulator oil passage and opened when hydraulic fluid flows from the reduction-side oil passage to the reduction-side oil chamber;
A check valve that is installed in the first accumulator oil passage and allows the hydraulic oil to flow from the extension-side oil passage to the accumulator;
A hydraulic circuit for hydraulic equipment, comprising: a reverse pilot check valve that is installed in a second accumulator oil passage and opens when hydraulic fluid flows from the reduction-side oil chamber to the reduction-side oil passage. A speed increasing valve that allows hydraulic oil to flow from the reduction side oil passage to the extension side oil passage by a differential circuit that communicates when the hydraulic oil flows from the extension side oil passage to the extension side oil chamber is a control valve. And between the hydraulic actuator and
A first accumulator oil passage branching from an extension side oil passage between the speed increasing valve and the control valve; a second accumulator oil passage branching from a reduction side oil passage between the speed increasing valve and the control valve; The hydraulic circuit for hydraulic equipment according to claim 1, wherein the hydraulic circuit is connected to an accumulator. A hydraulic actuator that operates the hydraulic device by expanding and contracting, a reduction side oil passage connected from the control valve to the reduction side oil chamber of the hydraulic actuator, and an extension side oil connected from the control valve to the extension side oil chamber of the hydraulic actuator A hydraulic circuit of a hydraulic device having a path,
A speed increasing valve that increases the extension speed of the hydraulic actuator is controlled by a differential circuit that communicates when hydraulic fluid flows from the expansion side oil passage to the extension side oil chamber. Installed between the valve and the hydraulic actuator,
A first accumulator oil passage branching from an extension side oil passage between the speed increasing valve and the hydraulic actuator; a second accumulator oil passage branching from a reduction side oil passage between the speed increasing valve and the hydraulic actuator; Is connected to the accumulator via a pilot control valve,
When hydraulic fluid flows from the reduction side oil passage to the reduction side oil chamber, the first accumulator oil passage is communicated with the accumulator by the pilot control valve, and the second accumulator oil passage is closed to extend from the extension side oil chamber. The hydraulic oil that has flowed into the side oil passage flows into the accumulator,
When hydraulic fluid flows from the extension side oil passage to the extension side oil chamber, the first accumulator oil passage is closed by the pilot control valve, and the second accumulator oil passage communicates with the accumulator, so that the hydraulic oil is reduced from the accumulator. A hydraulic circuit for hydraulic equipment, characterized by flowing in a side oil passage.

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