JP6559108B2 - Switching valve device - Google Patents

Description

  The present invention relates to a switching valve device that receives hydraulic pressure and opens one of two flow paths and closes the other.

  A switching valve device that mechanically couples and links two check valves is used in various hydraulic circuits. For example, in a hydraulic circuit that drives a double-acting single rod type hydraulic cylinder using a bi-directional pump and a motor, in order to compensate for the flow rate difference corresponding to the rod volume between the cylinder head side flow path and the cylinder rod side flow path. A switching valve device is used to supply differential hydraulic oil from the tank to the flow path and to return it to the tank.

  Various structures have been proposed for this type of switching valve device. Patent Document 1 discloses a structure in which two check valves are coupled by a rod-shaped shuttle.

  Patent Document 2 discloses a switching valve device having a structure in which both of two check valves are closed when no hydraulic pressure is applied.

  That is, in FIG. 5 showing the structure of a conventional switching valve device 201, the switching valve device 201 includes two check valves 203, 204 and a cylindrical shuttle rod 209 that mechanically couples the two check valves 203, 204. have. The two check valves 203 and 204 are both closed as shown in a non-pressurized state where no hydraulic pressure is applied to the flow path to be opened and closed. In a pressurized state in which hydraulic pressure is applied to one side (including a state in which a pressure greater than the other is applied to one side), one side to which hydraulic pressure is applied remains closed and the other opens.

  In FIG. 5, the housing 202 has a through hole 220 that extends over the entire length in the left-right direction. The through hole 220 includes a small-diameter portion 221 on which the shuttle rod 209 slides, two medium-diameter portions 222a and 222b formed on both sides of the small-diameter portion 221 and connected to the small-diameter portion 221, and two medium-diameter portions 222a and 222b. Two large-diameter portions 223a and 223b are connected to each other. The inner diameters of the medium diameter portions 222a and 222b are larger than the outer diameter of the shuttle rod 209 and smaller than the outer diameters of the valve bodies 205 and 206. The inner diameters of the large diameter portions 223a and 223b are larger than the outer diameters of the valve bodies 205 and 206. The valve bodies 205 and 206 are urged toward the valve seat by coil springs 207 and 208.

  The valve bodies 205 and 206 are provided with through holes 255 and 265 in which the large diameter portions 256 and 266 and the small diameter portions 257 and 267 are continuous. The end portions of the shuttle rod 209 are fitted into the large diameter portions 256 and 266, respectively. When hydraulic pressure is applied to the small diameter portions 257 and 267 of one of the two check valves 203 and 204, the valve body 205 and 206 of the one check valve where the shuttle rod 209 remains is pushed to Open the check valve.

Japanese Patent No. 4183632 Japanese Patent No. 5700409

  The conventional switching valve device 201 shown in FIG. 5 has the following problems.

  That is, the effective area of the hydraulic pressure acting in the direction of closing the valve bodies 205 and 206 is determined by the inner diameters of the medium diameter portions 222a and 222b, which are the inner diameters of the valve seats 231 and 232. On the other hand, the effective area of the hydraulic pressure acting in the direction of opening the counterpart valve bodies 205 and 206 is determined by the outer diameter of the shuttle rod 209, that is, the inner diameters of the large diameter portions 256 and 266.

  In the conventional structure, the inner diameter portions 222a and 222b are considerably larger in inner diameter than the larger diameter portions 256 and 266, and the effective area ratio is as large as about five times, for example.

  Therefore, even if hydraulic pressure is applied to one end surface of the shuttle rod 209, the counterpart valve bodies 205 and 206 cannot be opened when a predetermined hydraulic pressure is applied to the counterpart valve bodies 205 and 206. was there. Such a phenomenon may occur particularly when switching between forward and backward movement of the hydraulic cylinder, and the operation is unstable.

  The present invention has been made in view of the above-described problems, and provides a switching valve device with stable operation that can open a counterpart valve body even when a certain amount of hydraulic pressure is acting on the counterpart valve body. The purpose is to provide.

  A switching valve device according to an embodiment of the present invention is mounted in a housing and a hole provided in the housing, and the other valve body is separated from the valve seat in a state where one valve body is in contact with the valve seat and closed. Two check valves disposed opposite to each other via a shuttle so that the shuttle can be opened, and the shuttle includes a cylindrical rod portion and a flange portion having a diameter larger than that of the rod portion, The valve body has a rod sliding hole through which the rod portion slides, and a shuttle chamber in which the flange portion slides, and one of the two check valves. When a hydraulic pressure is applied in a closing direction with respect to the valve body, the hydraulic pressure acts on the flange portion and pushes the rod portion, whereby the shuttle pushes the valve body of the other check valve. Open the check valve.

The flange portion has an outer peripheral surface that slides tightly on the inner peripheral surface of the shuttle chamber, and the flange portion is in contact with the inner end surface of the shuttle chamber that communicates with the rod sliding hole. An annular protrusion is provided on the inner side from the outer peripheral edge of the flange portion to obtain a sealing property when contacting the surface with the inner end surface.

  Preferably, the ratio between the inner diameter of the inner peripheral surface of the shuttle chamber and the inner diameter of the valve seat is 1: 1.

  Preferably, the valve body is disposed so as to block the main valve body portion in which the shuttle chamber is formed and one end surface thereof is opened, and the open end surface of the main valve body portion, and is integrally coupled. The check valve is opened when the end of the shuttle abuts against the end face of the sub-valve body and pushes it.

  Preferably, the sub-valve part has a cylindrical guide part, and the guide part slides on an inner peripheral surface of a guide hole whose outer peripheral surface is fixed to the housing. A spring member that urges the valve body in the closing direction is provided on the inner peripheral surface side.

  Preferably, a cylindrical valve seat member on which the valve seat is formed is fitted and fixed in a hole provided in the housing, and the guide hole is formed on an inner peripheral surface of the valve seat member. The plug member formed with is fitted and fixed, and the spring member is provided between the plug member and the sub-valve body portion.

  Preferably, a hole for communicating the inside and the outside of the shuttle chamber is provided at the bottom of the shuttle chamber in the main valve body.

  Preferably, in the shuttle, two shuttle pieces each having the rod portion and the flange portion are coaxially arranged, and end portions of the rod portions can be pressed against each other. .

  Preferably, the shuttle piece is slidably supported by the inner peripheral surface of the shuttle chamber in the main valve body and the rod sliding hole.

  Preferably, when the hydraulic pressure is not applied in the closing direction with respect to the valve bodies of both of the two check valves, the valve bodies of the two check valves abut against the corresponding valve seats. Close both of the two check valves.

  ADVANTAGE OF THE INVENTION According to this invention, even when a certain amount of oil_pressure | hydraulic acts on the other party valve body, the other party valve body can be opened and the switching valve apparatus with stable operation | movement can be provided.

It is a cross-sectional front view of the non-pressurization state of the switching valve apparatus concerning the embodiment of the present invention. It is a section front view of the pressurization state of the change valve device concerning an embodiment of the present invention. It is a figure which expands and shows one check valve in FIG. It is an example of the circuit diagram of the hydraulic cylinder apparatus which has a switching valve apparatus. It is a cross-sectional front view which shows the structure of the conventional switching valve apparatus.

  1-3 is a sectional front view of the switching valve device 1 according to the embodiment of the present invention. FIG. 1 shows a non-pressurized state, and FIG. 2 shows a pressurized state. Since the check valve 3 is shown in detail in FIG. 3, FIG. 3 should be referred to in the description of the check valve 3 itself.

  1 and 2, the switching valve device 1 includes a housing 2 and two check valves 3 and 4 mounted in a hole 20 provided in the housing 2. The hole 20 includes holes 21, 22a, 23a, 22b, and 23b.

  The housing 2 is formed with a hole 25 communicating with the hole 21, holes 26 and 28 communicating with the hole 23a, and holes 27 and 29 communicating with the hole 23b.

  The check valves 3 and 4 include valve bodies 5 and 6, respectively. In a state where one valve body 5, 6 is in contact with the valve seat 31 and is closed, the two valve bodies 6, 5 can be opened away from the valve seat 31. The shuttle pieces 44a and 44b are arranged to face each other via a shuttle 44.

  In the shuttle 44, two shuttle pieces 44a and 44b each having a rod portion 441 and a flange portion 442 are arranged coaxially, and the end portions of the rod portions 441 can be pressed against each other. Yes.

  That is, each of the shuttle pieces 44 a and 44 b has a cylindrical rod portion 441 and a flange portion 442 having a diameter larger than that of the rod portion 441. The flange 442 slides in the shuttle chamber SH provided in the valve bodies 5 and 6. The rod portion 442 has a rod portion 445 having the same diameter as the rod portion 441 on the opposite side of the rod portion 441, and the end surface of the rod portion 445 can abut against the valve bodies 5 and 6 to push it. .

  When the hydraulic pressure is not applied in the closing direction with respect to both the valve bodies 5 and 6 of the two check valves 3 and 4, as shown in FIG. 6 abuts the corresponding valve seats 31 and closes both of the two check valves 3 and 4.

  That is, the holes 26 and 28, the holes 25, and the holes 27 and 29 are blocked from each other. The holes 26 and 28 and the holes 27 and 29 are always in communication. When the hydraulic pressure in the hole 25 becomes higher than the hydraulic pressure in the holes 26 and 28 or the holes 27 and 29, the corresponding check valves 3 and 4 are opened.

  On the other hand, when the hydraulic pressure is applied in the closing direction to one of the two check valves 3 and 4, for example, the valve body 6, as shown in FIG. Acting on 442 pushes the rod portion 441, whereby the shuttle 44 pushes the valve body 5 of the other check valve 3 to open the check valve 3.

  That is, when a hydraulic pressure is applied to the holes 27 and 29, the shuttle piece 44b is pushed to the left in FIGS. 1 and 2, whereby the shuttle piece 44a is pushed in the same manner, the check valve 3 is opened, and the hole 26 is opened. , 28 and the hole 25 communicate with each other.

  Hereinafter, the configuration of the switching valve device 1 will be described in detail.

  Since the structures of the two check valves 3 and 4 are the same as each other, only one check valve 3 will be mainly described unless particularly necessary. In addition, regarding the corresponding components in the check valves 3 and 4, the check valve 3 may be indicated with a symbol “a”, and the check valve 4 may be indicated with a symbol “b”.

  As shown in FIGS. 1 to 3, the housing 2 of the switching valve device 1 has a hole 20 that penetrates over the entire length in the left-right direction. Some of the holes 20 are the holes 22a, 23a, 22b, and 23b described above. Screws are formed at openings at both ends of the hole 20, and the check valves 3 and 4 are screwed and fixed therein.

  Referring mainly to FIG. 3, the check valve 3 includes a valve seat member 41a, a valve body 5, a shuttle piece 44a, a plug member 47a, and the like.

  The valve seat member 41a has a cylindrical shape, and a valve seat 31 is formed on the inner side of the distal end portion. The valve seat member 41a is fitted into the hole 23a, and the position of the valve seat member 41a is adjusted in the axial direction by screw connection with the screw of the opening portion of the hole 20. It is fixed by 45a.

  The outer peripheral surface of the valve seat member 41a and the hole 23a and the hole 22a are sealed with two packings, respectively. Holes 411 are provided at four locations on the peripheral surface of the valve seat member 41a, thereby communicating the inside and the outside of the valve seat member 41a.

  Thus, the cylindrical valve seat member 41a in which the valve seat 31 is formed is fitted into the screw at the opening of the hole 20, and is fixed by screw connection.

  The valve body 5 is disposed so as to close the main valve body portion 43a in which the shuttle chamber SH is formed and one end surface thereof is opened, and the open end surface of the main valve body portion 43a, and are integrally coupled by screws. And the auxiliary valve body portion 42a.

  The main valve body 43a includes a small-diameter cylindrical portion 431, a bottom plate portion 432, and a large-diameter cylindrical portion 433.

  The small diameter cylindrical portion 431 is cylindrical and has a rod sliding hole 431a. The bottom plate part 432 has an annular shape and has a plurality of holes 437 penetrating between both surfaces. Through the hole 437, the space SHb and the hole 25 communicate with each other. A seal portion 32 having an inclined surface for contacting and sealing the valve seat 31 is provided at an edge of the outer surface of the bottom plate portion 432.

  The valve seat 31 also has an inclined surface, and the inclination angle of the valve seat 31 and the inclination angle of the seal portion 32 are slightly deviated by, for example, about 1 degree. It prevents biting and wear when the surfaces come into contact.

  The large-diameter cylindrical portion 433 is formed with the above-described shuttle chamber SH on the inner peripheral surface side, and the flange portion 442 slides densely. The large-diameter cylindrical portion 433 is provided with a plurality of holes 436 so as to communicate with the space SHa on the opposite side of the bottom plate portion 432 in the shuttle chamber SH.

  The shuttle piece 44a is slidably supported by the inner peripheral surface of the shuttle chamber SH in the main valve body 43a and the rod sliding hole 431a.

  The flange portion 442 of the shuttle piece 44a is in contact with the surface facing the space SHb, that is, the surface facing the bottom plate portion 432, in other words, the inner end surface 435 on the side communicating with the rod sliding hole 431a in the shuttle chamber SH. An annular projection 443 for obtaining a sealing property when abutting against the inner end surface 435 is provided on the surface on the contact side.

  The protruding portion 443 is provided slightly inside from the outer peripheral edge of the flange portion 442. Taking an example of the dimensions of the protrusion 443, the height is about 0.5 to 1 mm and the width is about 1 mm. Other dimensions may be used. Note that the hole 437 described above is provided on the inner side in the radial direction than the protrusion 443.

  Therefore, in FIG. 3, hydraulic pressure is applied to the hole 26, whereby the valve body 5 moves rightward and the seal portion 32 contacts the valve seat 31, thereby closing the check valve 3. At this time, the hydraulic pressure flows into the shuttle chamber SH through the hole 436, and the shuttle piece 44a moves in the same manner by pushing the flange 442 to the right by the hydraulic pressure, so that the protrusion 443 contacts the inner end surface 435. Seal this part in contact to prevent hydraulic leaks. As a result, the gap between the hole 26 and the hole 25 is blocked.

  The sub valve body part 42 a has a guide part 421 and a screwed part 422.

  The guide portion 421 has a cylindrical shape, and the outer peripheral surface thereof slides on the inner peripheral surface of the guide hole 471 of the plug member 47 a that is fixedly provided to the housing 2. An inner peripheral surface side of the guide portion 421 is a spring chamber, and a spring member 7a that biases the valve body 5 in the closing direction is provided. The guide portion 421 is provided with a plurality of holes 424 so that the inner peripheral surface side that is a spring chamber communicates with the outer peripheral surface side that communicates with the hole 26.

  The screwed portion 422 is provided with a screw on a part of the outer peripheral surface, and is screwed with a screw provided on the inner peripheral surface of the large-diameter tubular portion 433 of the main valve body portion 43a, and these are integrally coupled. The screw-in portion 422 is provided with a plurality of holes 425 for communicating the spring chamber of the guide portion 421 and the shuttle chamber SH.

  Thus, the stopper member 47a formed with the guide hole 471 is fitted into the inner peripheral surface of the valve seat member 41a, and the position of the valve seat member 41a is adjusted in the axial direction by screw and screw coupling. It is fixed by a lock nut 46a. By adjusting the position of the plug member 47a in the axial direction, the strength of the spring member 7a can be adjusted. The space between the outer peripheral surface of the plug member 47a and the inner peripheral surface of the valve seat member 41a is sealed with packing.

  By the way, the inner diameter of the inner peripheral surface of the shuttle chamber SH, that is, the outer diameter D1 (see FIG. 3) of the flange 442 and the inner diameter D2 of the valve seat 31 are substantially the same, that is, the ratio D1: D2 is 1: 1. Is formed. Therefore, the effective area for pushing the shuttle piece 44a by the hydraulic pressure becomes larger than before, and the other side shuttle piece 44b can be pushed with a large thrust, and the other side check valve 4 can be opened reliably. In addition, since the effective area of the shuttle piece 44a and the effective area of the valve body 5 are substantially the same, the force which pushes the shuttle piece 44a with a hydraulic pressure becomes substantially the same as the force which closes the valve body 5 with the same hydraulic pressure.

  Next, the operation and operation of the switching valve device 1 will be described.

  FIG. 4 shows an example of a circuit diagram of the hydraulic cylinder device 100 having the switching valve device 1.

  In FIG. 4, the hydraulic cylinder device 100 includes a single rod type double acting hydraulic cylinder 110, a hydraulic unit 120 that supplies hydraulic pressure to the hydraulic cylinder 110, a tank 150, the switching valve device 1, and the like. The hydraulic unit 120 includes a pump 122, a motor 123, and a worm gear mechanism 124 for manual driving.

  The pump 122 is a bidirectional pump capable of rotating and discharging in both forward and reverse directions, and is hydraulically connected to the forward port PT1 and the backward port PT2 of the hydraulic cylinder 110 via the flow paths L1 and L2. Are provided with two supply / discharge ports PA and PB. A servo-controlled motor 123 selectively rotates the pump 122 in either the forward direction or the reverse direction. Depending on the direction of rotation of the pump 122, hydraulic pressure (hydraulic pressure) is generated at either the supply / discharge port PA or PB.

  A length measuring sensor 115 is inserted into a hole provided in the center of the piston rod 114 of the hydraulic cylinder 110, and a stroke position is detected by a signal from the length measuring sensor 115 corresponding to the stroke position of the piston 113.

  The tank 150 accommodates pressure oil that compensates for excess or deficiency of pressure oil due to the difference in effective area of the cylinder chamber of the hydraulic cylinder 110, volume change due to circuit temperature, and loss due to leakage.

  In the switching valve device 1, the hole 27 is connected to the forward flow path L1, the hole 26 is connected to the backward flow path L2, and the hole 25 is connected to the tank 150. Of the two check valves 3 and 4 of the switching valve device 1, one check valve 3 opens and closes a branch flow path L3 connecting the flow path L2 and the tank 150, and the other check valve 4 includes the flow path L1 and the tank. The branch flow path L4 connecting 150 is opened and closed.

  In the hydraulic cylinder device 100 configured as described above, when hydraulic pressure is generated in the supply / discharge port PA of the pump 122, the piston of the hydraulic cylinder 110 moves to the rod side. At this time, hydraulic pressure is applied to the hole 27 of the switching valve device 1, the check valve 4 is closed, and the shuttle 44 moves to the left in FIGS. 1 and 2.

  As a result, as shown in FIG. 2, the valve element 5 is pushed by the shuttle 44 and moves to the left, and the check valve 3 is opened. Thereby, the pressure oil in the tank 150 flows into the supply / discharge port PB of the pump 122 through the branch flow path L3 and the flow path L2.

  Further, when hydraulic pressure is generated at the supply / discharge port PB of the pump 122, the piston of the hydraulic cylinder 110 moves to the head side. At this time, hydraulic pressure is applied to the hole 26 of the switching valve device 1, the check valve 3 is closed, and the shuttle 44 moves to the right in FIGS.

  As a result, the valve body 6 is pushed by the shuttle 44 and moves to the right, and the check valve 4 is opened. As a result, part of the pressure oil flowing out from the port PT1 in the head side chamber of the hydraulic cylinder 110 flows into the tank 150 through the branch flow path L4.

  In such an operation, when hydraulic pressure is applied to the hole 26 or the hole 27, the presence of the flange portion 442 makes the effective area for pushing the shuttle piece 44 a larger than that without the flange portion 442, and the shuttle 44. A large thrust is generated to move the valve, and the check valve can be opened reliably by pushing it regardless of the condition of the counterpart valve body. Therefore, even when the hydraulic cylinder 110 is switched between forward and backward movement, the check valves 3 and 4 are surely opened and closed, and the operation is stable.

  Further, when the pump 122 is driven manually, the discharge flow rate is small, but even with a small discharge flow rate, the opening and closing operation of the check valves 3 and 4 of the switching valve device 1 is reliable and the operation is stable. That is, the switching valve device 1 has good responsiveness of the check valves 3 and 4 and can be easily controlled even when the pump 122 is rotating at a low speed. Therefore, since no unnecessary flow rate of pressure oil is required, heat generation is reduced and efficiency is improved.

  As described above, the switching valve device 1 according to the present embodiment can reliably operate in response to a weak pressure change as in manual driving. The switching valve device 1 is useful for switching a flow path leading to a tank to compensate for excess or deficiency of pressure oil due to a difference in effective area of the cylinder chamber, volume change due to circuit temperature, loss due to leakage, and the like. .

  In the embodiment described above, the configuration, shape, dimensions, material, and the like of the entire switching valve device 1 or each part may be various other than those described above in accordance with the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Switching valve apparatus 2 Housing 20 21, 22a, 23a, 22b, 23b Hole 3, 4 Check valve 5, 6 Valve body 31 Valve seat 32 Seal part 41a Valve seat member 42a Subvalve body part 421 Guide part 422 Screwed part ( bottom)
425 hole 43a main valve body part 431 small diameter cylindrical part 431a rod sliding hole 44 shuttle 44a, 44b shuttle piece 441 rod part 442 flange 443 protrusion 47a plug member 471 guide hole SH shuttle chamber 7 spring member

Claims (10)

A housing;
Mounted in a hole provided in the housing, facing one another via a shuttle so that one valve body is in contact with the valve seat and closed while the other valve body can be opened away from the valve seat. Two check valves arranged, and
The shuttle
A cylindrical rod part, and a flange part having a diameter larger than the rod part,
The valve body is
A rod sliding hole through which the rod portion slides, and a shuttle chamber in which the flange portion slides,
When a hydraulic pressure is applied in a closing direction to the valve body of one of the two check valves, the hydraulic pressure acts on the collar portion to push the rod portion, thereby causing the shuttle to move to the other valve body. Push the valve body of one check valve to open the check valve ,
As for the said collar part, an outer peripheral surface slides the inner peripheral surface of the said shuttle chamber closely,
The collar has an annular shape for obtaining a sealing property when abutting between the inner end surface and the inner end surface of the shuttle chamber that is in contact with the inner end surface of the shuttle chamber. Is provided on the inner side from the outer peripheral edge of the flange,
A switching valve device characterized by that. The ratio between the inner peripheral surface inner diameter as the inner diameter of the valve seat of the shuttle chamber is formed on a one-to-one,
The switching valve device according to claim 1 or 2. The valve body is
A main valve body portion in which the shuttle chamber is formed and one end face thereof is opened;
A sub-valve body part that is arranged so as to close the open end face of the main valve body part and is integrally coupled,
The check valve is opened by pushing the end of the shuttle against the end face of the sub-valve body,
The switching valve device according to claim 1 or 2 . The sub-valve part has a cylindrical guide part,
The guide portion has a spring member whose outer peripheral surface slides on an inner peripheral surface of a guide hole fixedly provided with respect to the housing and biases the inner peripheral surface side in a direction to close the valve body. Is provided,
The switching valve device according to claim 3 . In the hole provided in the housing, a cylindrical valve seat member having the valve seat formed at the tip is fitted and fixed,
A plug member in which the guide hole is formed is fitted and fixed to the inner peripheral surface of the valve seat member,
The spring member is provided between the plug member and the sub-valve part.
The switching valve device according to claim 4 . The peripheral surface of the valve seat member is provided with a hole that communicates the inside and the outside of the valve seat member,
A gap is provided between an inner peripheral surface connected to the valve seat of the valve seat member and an outer peripheral surface of the main valve body part,
The switching valve device according to claim 5. The bottom of the shuttle chamber in the main valve body is provided with a hole that communicates the inside and the outside of the shuttle chamber.
The switching valve device according to any one of claims 3 to 6 . The shuttle
Two shuttle pieces each having the rod portion and the flange portion are arranged coaxially, and the end portions of the rod portions can be brought into contact with each other and pressed against each other.
The switching valve device according to any one of claims 1 to 7. By the inner peripheral surface and the rod sliding hole of the shuttle chamber in the main valve body portion, the shuttle piece is slidably supported,
The switching valve device according to claim 8. When the hydraulic pressure is not applied in the closing direction with respect to the valve bodies of both of the two check valves, the valve bodies of both of the two check valves abut against the corresponding valve seats, and two Close both of the check valves,
The switching valve device according to any one of claims 1 to 9.

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