JP4405851B2 - Cylinder device - Google Patents

Description

The present invention relates to a cylinder device .

  In the conventional cylinder device 107, as proposed by the applicant, for example, as shown in FIG. 4, the bidirectional discharge pump 100, the cylinder 101, and the bidirectional discharge pump 100 and the cylinder 101 are connected. In order to prevent adverse effects such as cavitation by applying a certain amount of pressure in the cylinder circuit 102 on the low pressure side when the bidirectional discharge pump 100 is driven. In addition, a bypass circuit 103 that bypasses the bidirectional discharge pump 100 is provided in the cylinder circuit 102, and a low-pressure priority shuttle valve 105 that is connected to the accumulator 104 is provided in the middle of the bypass circuit 103 (see, for example, Patent Document 1).

In the case of the cylinder device 107, a stop valve 106 is provided to supply hydraulic oil to the cylinder circuit 102 and the cylinder 101 or to discharge the hydraulic oil from the cylinder circuit 102 and the cylinder 101 during maintenance of the cylinder device 107. .
JP 2002-276606 (from page 2, right column, line 40 to page 3, left column, line 12; FIG. 1)

  However, the above-described conventional cylinder device does not have a functional problem, but has the following adverse effects.

  That is, when disassembling the cylinder device 107 for maintenance of the cylinder device 107, it is first necessary to open the stop valve 106 and discharge the hydraulic oil from the cylinder device 107. At this time, the accumulator The hydraulic oil accumulated and filled in 104 is also discharged together. After the cylinder device 107 is assembled, the accumulator 104 must be accumulated and filled again, and maintenance work can be performed. It becomes complicated and the maintenance cost increases accordingly.

  Therefore, the present invention has been developed to improve the above-described adverse effects, and its object is to simplify maintenance work and reduce maintenance costs.

In order to achieve the above-described object, the present invention basically provides a hydraulic device including an accumulator provided in a hydraulic circuit, and the outflow of liquid in the accumulator is between the hydraulic circuit and the accumulator. A stop valve is provided to prevent this.

Specifically, a cylinder, a hydraulic pressure source that selectively supplies hydraulic pressure to the two pressure chambers via a cylinder circuit that communicates the two pressure chambers formed in the cylinder, and the two A bypass passage communicating with the pressure chamber in parallel with the cylinder circuit, a low pressure priority type shuttle valve provided in the middle of the bypass path, and an outlet end of the low pressure priority type shuttle valve are connected via a drain passage. In the cylinder device comprising the accumulator, a stop valve is provided in the middle of the drain passage to prevent the liquid from flowing out of the accumulator, and the stop valve communicates with the outlet end of the accumulator and the drain passage, An annular valve seat provided in the valve case, a valve body that is separated from and seated on the annular valve seat, an urging means that urges the valve body in a direction of seating on the valve seat, and a valve body that is separated from the valve seat Do Is composed of a fixing means for fixing the state, securing means, characterized in that the screw hole formed in the valve case, a screw member that is screwed into the screw hole.

According to the present invention, the liquid in the accumulator is maintained without being discharged by the stop valve during maintenance, and can be used as it is even after the maintenance is completed. It is not necessary to accumulate and fill the liquid inside, and the maintenance work is simplified, and the maintenance cost is reduced accordingly. And since the fixing means in the stop valve is composed of a screw member and a screw hole, the stop valve can be configured with a small number of parts, and the processing is also simplified, thereby reducing the cost and space saving of the cylinder device. Enable.

  Conventionally, the liquid discharged during maintenance leaks due to the pressure of the accumulator, and this leaked liquid was discarded, but it was prevented from flowing out of the accumulator, and the liquid leaked during maintenance. Since the liquid is not discharged, the corresponding liquid is not wasted and energy is saved.

  The present invention will be described below based on the illustrated embodiment. FIG. 1 is a circuit diagram of a cylinder device according to an embodiment. FIG. 2 is an enlarged cross-sectional view of the stop valve of the cylinder device according to the embodiment. FIG. 3 is an enlarged cross-sectional view of a stop valve of a cylinder device according to a modification of the embodiment.

  As shown in FIG. 1, the basic structure of the cylinder device S according to the embodiment includes a cylinder 1, a cylinder circuit 2 that communicates two pressure chambers R <b> 1 and R <b> 2 formed in the cylinder 1, and the cylinder circuit 2. A bidirectional discharge pump 10 serving as a hydraulic pressure source for selectively supplying hydraulic pressure to the two pressure chambers R1 and R2 through the cylinder and the two pressure chambers R1 and R2 are connected in parallel to the cylinder circuit 2. Connected to the bypass path 6, the low pressure priority type shuttle valve 7 in the middle of the bypass path 6, the drain path 9 connected to the outlet end 8 c of the low pressure priority type shuttle valve 7, and the other end of the drain path 9. The accumulator 4, a stop valve 11 provided in the middle of the drain passage 9, a supply / discharge passage 12 branched from the middle of the drain passage 9, and a stop valve 13 provided at the end of the supply / discharge passage 12. Is done.

  Hereinafter, the cylinder 1 will be described in detail. The cylinder 1 includes a cylindrical cylinder body C, a piston P slidably inserted into the cylinder body C, and a rod R penetrating the axial center portion of the piston P. The cylinder main body C is filled with a liquid such as hydraulic oil, and the cylinder main body C has a pressure chamber R1 and a cylinder main body C outside. And a port b for communicating the pressure chamber R2 and the outside of the cylinder body C.

  Further, the port a is connected to one end of the cylinder circuit 2, and the port b is connected to the other end of the cylinder circuit 2. Therefore, the pressure chamber R1 and the pressure chamber R2 communicate with each other via the cylinder circuit 2. Has been.

  A bidirectional discharge pump 10 serving as a hydraulic pressure source is provided in the middle of the cylinder circuit 2. Although not shown in detail, the bidirectional discharge pump 10 is driven by a motor M, and the liquid discharge direction can be switched by normal rotation and reverse rotation of the motor M. A known pump is used. Is possible.

  Further, in the middle of the cylinder circuit 2, a bypass path 6 is connected so as to bypass the bidirectional discharge pump 10. That is, the bypass 6 is connected to the cylinder 1 in parallel with the cylinder circuit 2. A low-pressure priority shuttle valve 7 is provided in the middle of the bypass path 6. In the illustrated case, the bypass path 6 is connected to the cylinder circuit 2 in order to avoid unnecessarily increasing the pipe length, but the bypass path 6 is directly connected to the pressure chambers R1 and R2 of the cylinder 1. It may be connected.

  The low-pressure priority shuttle valve 7 has three ports, a port 8a, a port 8b, and a port 8c as an outlet end. For example, when the pressure on the port 8a side is higher than the pressure on the port 8b side, the port 8a side When the flow path on the port 8b side is opened and the flow path on the port 8b side is opened, the port 8b and the port 8c are in communication with each other, and the pressure on the port 8b side is higher than the pressure on the port 8a side. At the same time, the flow path on the port 8a side is opened, and the port 8a and the port 8c are in communication with each other. The port 8 c which is the outlet end of the low pressure priority shuttle valve 7 is connected to the drain passage 9.

  The other end of the drain passage 9 is connected to the accumulator 4 and is connected to a stop valve 13 through a supply / discharge passage 12 branched from the middle of the drain passage 9. A stop valve 11 is provided on the accumulator 4 side from the supply / discharge passage 12.

  The stop valve 11 is normally opened, and the port 8c, which is the outlet end of the low-pressure priority shuttle valve 8, is in communication with the accumulator 4 at normal times. The stop valve 13 is used to supply and discharge the liquid when the liquid in the cylinder 1 of the cylinder device S and the circuit is excessive or insufficient. As the accumulator 4, a known type such as a diaphragm type, a bladder type, and a piston type can be used, and an optimum one may be used depending on the application.

  Specifically, as shown in FIG. 2, the stop valve 11 includes a hollow valve case 21 that connects the outlet end 20 of the accumulator 4 and the drain passage 9, and an annular valve provided in the valve case 21. A seat 22, a valve body 23 that is detachably seated on the annular valve seat 22, a biasing spring 24 that is a biasing means that biases the valve body 23 in a direction in which the valve body 23 is seated on the valve seat 22, and the valve body 23 is It is comprised with the fixing means 25 fixed to the state which leaves | separates from.

  More specifically, the valve case 21 includes a bottomed cylindrical case main body 21a and a hollow connecting member 21b that connects the case main body 21a and the drain passage 9, and is connected to the case main body 21a and the connecting member 21b. 2 is provided with a hole 21c into which the valve body 23 is inserted, the open end of the case body 21a is connected to the outlet end 20 of the accumulator 4, and the left end of the connecting member 21b in FIG. It is connected. An annular valve seat 22 is provided at the opening end of the hole 21c on the case body 21a side.

  The valve body 23 includes a bottomed cylindrical valve body main body 23a, a rod portion 23b extending from the bottom, a tapered portion 23c formed from the side of the valve body main body 23a to the bottom, and the valve body main body 23a. The rod part 23b is movably inserted into the hole 21c. Further, a biasing spring 24, which is a biasing means, is inserted into the valve body 23a, so that the biasing spring 24 is interposed between the peripheral portion of the outlet end 20 of the accumulator 4 and the valve body 23. The valve body 23 is urged toward the case main body 21a. And the valve body 23 is always urged | biased by the cyclic | annular valve-seat 22 side by the urging | biasing force of this urging | biasing spring 24, and the force which opposes the urging | biasing spring 24 from the upper direction in FIG. Sometimes, the tapered portion 23c of the valve body 23 is seated on the valve seat 22, and the drain passage 9 is shut off.

  Further, the connecting member 21b is provided with a screw hole 21d that opens from above in FIG. 2. The screw hole 21d includes a screw portion 31 and a flange portion 32 extending from the screw portion 31. When the screw member 30 is screwed and the screw member 30 is rotated and tightened with respect to the linkage member 21b, the valve body 23 is pushed by the screw member 30 and is separated from the valve seat 22, so that the accumulator The inside of 4 can open the drain channel | path 9 through the hole 23d provided in the valve body 23, and can maintain it in the state. Therefore, the fixing means 25 in the present embodiment includes the screw member 30 and the screw hole 21d.

  Further, a notch 21e is provided at the opening end of the screw hole 21d, and an O-ring 40 is inserted into the notch 21e. Therefore, the O-ring 40 is interposed between the flange portion 32 and the opening end portion of the screw hole 21d. When the screw member 30 is fastened to the connecting member 21b, the O-ring 40 is pressed. Naturally, the gap between the connecting member 21 b and the screw member 30 is naturally sealed. On the contrary, the screw member 30 is loosened with respect to the connecting member 21 b, and the valve body 23 is moved to the valve seat 22 by the biasing force of the biasing spring 24. Even in the seated state, the O-ring 40 is maintained in a compressed state by the flange portion 32 and the open end portion of the screw hole 21d. Therefore, even when the valve body 23 is detached from and seated on the valve seat 22, the space between the screw member 30 and the connecting member 21 b is surely sealed by the O-ring 40. Is prevented from leaking from the cylinder device S.

  Further, as described above, the stop valve 11 is integrally provided at the outlet end 20 of the accumulator 4, and the cylinder device S can be made compact.

  The cylinder device S is configured as described above, and the operation thereof will be described.

  First, the function as a cylinder will be described. When the rod R of the cylinder 1 is driven to the right in FIG. 1, the motor M is rotated forward and the bidirectional discharge pump 10 is rotated forward. Then, the liquid discharged from the bidirectional discharge pump 10 flows into the pressure chamber R1 in the cylinder 1 via the cylinder circuit 2 and expands the volume of the pressure chamber R1, that is, the piston P is moved to the right in FIG. The rod R is pushed toward the right in FIG. On the other hand, since the volume of the pressure chamber R <b> 2 to be compressed decreases, the excess liquid in the pressure chamber R <b> 2 is guided to the suction port of the bidirectional discharge pump 10 via the cylinder circuit 2. At this time, the pressure in the cylinder circuit 2 on the low pressure side is compensated by the accumulator 4 because the port 8b and the port 8c of the low pressure priority shuttle valve 7 provided in the middle of the bypass passage 6 are in communication with each other. Is prevented. On the other hand, when the rod R is driven to the left in FIG. 1, the motor M may be reversed and the bidirectional discharge pump 10 may be reversed. In this case, the operation is only reversed left and right.

  Further, for example, when the volume of the liquid in the cylinder 1, the cylinder circuit 2, and the bypass path 6 increases due to the temperature rise, excess liquid flows into the accumulator 4, and the cylinder 1 and the cylinder circuit When the volume of the liquid in 2 and the bypass path 7 is reduced in volume due to a temperature drop, the insufficient liquid flows from the accumulator 4 into the cylinder 1, the cylinder circuit 2 and the bypass path 6. The change is compensated, and as a result, adverse effects such as damage due to the liquid volume change of the cylinder device S are prevented.

  Next, maintenance of the cylinder device S will be described. At the time of this maintenance, the cylinder device S is disassembled. First, the stop valve 11 is operated to block the drain passage 9 so that liquid does not flow out from the accumulator 4. Specifically, by loosening the screw member 30 with respect to the connecting member 21b, the tapered portion 23c of the valve body 23 is brought into contact with the valve seat 22 and the drain passage 9 is blocked.

  In this state, the stop valve 13 is opened, and the liquid is discharged from the cylinder device S. At this time, the liquid in the accumulator 4 does not flow out by the stop valve 11, so that the accumulated pressure remains.

  Then, after disassembling the cylinder device S, maintenance work is performed, the cylinder device S is assembled again, and liquid is supplied into the cylinder device S from the stop valve 13. After the liquid supply operation is completed, the stop valve 11 is operated to connect the drain passage 9. Specifically, the screw member 30 is tightened with respect to the connecting member 21b, whereby the tapered portion 23c of the valve body 23 is separated from the valve seat 22, and the drain passage 9 is communicated.

  Then, the liquid in the accumulator 4 is maintained without being discharged by the stop valve 11 during the maintenance, and can be used as it is for the cylinder device S even after the maintenance is completed. Therefore, it is not necessary to accumulate and fill the accumulator 4 with the liquid, and the maintenance work is simplified, and the maintenance cost is reduced accordingly.

  Conventionally, the liquid discharged at the time of maintenance leaks due to the pressure of the accumulator 4, and the leaked liquid is discarded. However, the liquid is prevented from flowing out of the accumulator 4, and the liquid is discharged at the time of maintenance. Does not leak out, so that much liquid is not wasted and energy is saved.

  Next, a modification of the embodiment shown in FIG. 3 will be described. In this modified example, only the specific configuration of the stop valve 11 is different, so only the different parts will be described.

  The stop valve 11 includes an annular valve seat 41 provided in the middle of a hollow valve case 44 that forms a part of the drain passage 9, and a valve body that has a distal end separated from and seated on the valve seat 41 and a screw portion on a side portion. 42 and a screw hole 43 provided in the middle of the valve case 44 forming a part of the drain passage 9.

  The valve seat 41 is provided in a hollow valve case 44 connected to the outlet end 20 of the accumulator 4, and a valve body 42 screwed into a screw hole 43 provided in the valve case 44 at the top in FIG. 3. The drain passage 9 is blocked by the seating of the tip of the drain.

  Further, when the valve body 42 is loosened with respect to the valve case 44, the tip of the valve body 42 can be separated from the valve seat 41 to open the drain passage 9.

  Therefore, in this modified example, the stop valve 11 can be configured with a small number of parts, and the processing thereof is simple, so that the cost of the cylinder device can be reduced and the space can be saved. .

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a circuit diagram which shows the principle of the cylinder apparatus by this invention . It is an expanded sectional view of a stop valve of a cylinder device in one embodiment. It is an expanded sectional view of a stop valve of a cylinder device in a modification of an embodiment. It is a circuit diagram of the conventional cylinder apparatus.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Cylinder circuit 4 Accumulator 6 Bypass path 7 Low pressure priority shuttle valve 8a, 8b, 8c, a, b Port 9 Drain path 10 Bidirectional discharge pump 11 and 13 stop valve 12 as fluid pressure source 12 Supply and exhaust path 21, 44 Valve Case 21a Case body 21b Linking member 21c Hole 21d, 43 Screw hole 21e Notch 22, 41 Valve seat 23, 42 Valve body 23a Valve body main body 23b Rod portion 23c Taper portion 23d Hole 24 Biasing spring 30 Screw member 31 Screw part 32 Hook 40 O-ring C Cylinder body M Motor P Piston R Rod R1, R2 Pressure chamber S Cylinder unit

Claims (2)

A cylinder, a hydraulic pressure source that selectively supplies hydraulic pressure to the two pressure chambers via a cylinder circuit that communicates the two pressure chambers formed in the cylinder, and a cylinder circuit that communicates the two pressure chambers A cylinder comprising: a bypass path provided in parallel; a low-pressure priority type shuttle valve provided in the middle of the bypass path; and an accumulator connected to the outlet end of the low-pressure priority type shuttle valve via a drain passage In the apparatus, a stop valve for preventing the liquid in the accumulator from flowing out is provided in the middle of the drain passage, and the stop valve is provided in the valve case with a hollow valve case communicating the outlet end of the accumulator and the drain passage. An annular valve seat, a valve body that is detachably seated on the annular valve seat, an urging means that urges the valve body in the direction of seating on the valve seat, and a fixing that fixes the valve body in a state of being seated away from the valve seat Is composed of a stage, the fixing means is a cylinder and wherein the a screw hole formed in the valve case, a screw member that is screwed into the screw hole. The screw member includes a flange portion extending from the screw portion, an O-ring is interposed between the flange portion and the opening end portion of the screw hole, and the O-ring is in the state where the valve body is seated on the valve seat. The cylinder device according to claim 1, wherein the cylinder device is maintained in a compressed state by a flange and an opening end portion of the screw hole.

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