JP3209466U - Control valve and relief valve - Google Patents

Abstract

Provided are a control valve and a relief valve that are used in a hydraulic mechanism and prevent a sleeve from coming off. A control valve including a casing (1) having a hydraulic circuit therein and a relief valve (3) provided in the hydraulic circuit and attached to the casing (1), wherein the relief valve (3) has a sleeve insertion hole therein. And a sleeve 7 having a pilot chamber 7x in the base end portion of which is inserted into the sleeve insertion hole, and is formed in the main valve body 8 and the sleeve 7 that can move forward and backward in the sleeve 7. A main valve seat 9 on which a main valve body 8 can be seated is provided. A main valve portion 4 that opens when a pressure difference is generated between the inside and the outside of the pilot chamber 7x, and a pilot valve provided on the inner surface of the sleeve 7 And a sealing member 17 for preventing the hydraulic fluid from leaking from the inside of the chamber 7x, and the sleeve 7 comes into contact with the casing 1 to prevent the sleeve 7 from coming off. It has an eye 18. [Selection] Figure 2

Description

  The present invention relates to a control valve and a relief valve used in a hydraulic mechanism.

  Conventionally, a relief valve has been used for the purpose of controlling the hydraulic pressure in the hydraulic circuit, such as controlling the maximum pressure of the cylinder port in the control valve (see, for example, Patent Document 1).

  As shown in FIG. 4, this type of relief valve is generally attached to a casing a1 of a control valve, and includes a valve body a6 having a sleeve insertion hole a6x therein, and the sleeve insertion hole a6x. A sleeve a7 having a spring chamber a7x which is inserted into the end and having a spring chamber a7x therein, a pilot valve body a10 capable of moving forward and backward within the valve body a6, and a pilot valve seat a11 on which the pilot valve body a10 can be seated. A pilot valve portion a5 that is formed using a pilot valve seat member a12 and opens when the pressure in the spring chamber a7x exceeds a predetermined pressure; a main valve body a8 that can move back and forth in the sleeve a7; A main valve seat a9 formed on the sleeve a7 and on which the main valve body a8 can be seated; And a main valve portion a4 which opens when the pressure difference is generated between. In addition, a seal member a17 is disposed between the sleeve a7 and the pilot valve seat member a12 so as to prevent the hydraulic fluid from leaking from the spring chamber a7x.

  More specifically, the relief valve a3 shown in FIG. 4 is used to control the pressure of the cylinder port a1c below a predetermined value. The hydraulic pressure in the cylinder port a1c is guided to the spring chamber a7x through an orifice provided in the main valve body a8. When the pressure in the cylinder port a1c is less than or equal to a predetermined value, the second biasing means a16 for seating the pilot valve body a10 on the pilot valve seat a11 rather than the force derived from the hydraulic pressure in the cylinder port a1c. The pilot valve body a10 maintains the state of being seated on the pilot valve seat a11. At this time, since there is no hydraulic pressure difference between the inside and outside of the spring chamber a7x, the main valve body a8 is also driven by the biasing force of the first biasing means a15 disposed in the spring chamber a7x. The state of sitting on the valve seat a9 is maintained. When the pressure in the cylinder port a1c exceeds a predetermined value, the force derived from the hydraulic pressure in the cylinder port a1c overcomes the force by the second urging means a16, and the pilot valve body a10 is separated from the pilot valve seat a11. When the hydraulic fluid in the spring chamber a7x is guided to the tank port, a hydraulic pressure difference is generated between the spring chamber a7x and the cylinder port a1c. At this time, the main valve body a8 is separated from the main valve seat a9, and a part of the hydraulic fluid in the cylinder port a1c is guided to the tank port.

JP 2000-740003 A

  Accordingly, when the sleeve a7 rotates in a direction away from the valve body a6 due to fluid force or the like, the following problems may occur.

  That is, when the sleeve a7 moves greatly in the direction away from the valve body a6, at least a part of the seal member a17 is not sandwiched between the sleeve a7 and the pilot valve seat member a12, and the hydraulic fluid in the spring chamber a7x is removed. The function of preventing the spring chamber a7x from flowing out is not performed. At this time, the hydraulic fluid flows out from the spring chamber a7x to the tank port even though the hydraulic pressure in the cylinder port a1c is lower than a predetermined value, and a pressure difference is generated between the cylinder port a1c and the spring chamber a7x. Therefore, the main valve body a8 is separated from the main valve seat a9, and a part of the hydraulic fluid in the cylinder port a1c is unintentionally guided to the tank port. At this time, there arises a problem such that the loading platform loaded with the luggage is unintentionally lowered.

  The above-mentioned problems are not limited to the case where the sleeve is screwed to the valve body, but the relief valve in general is configured such that the proximal end portion of the sleeve is inserted into the valve body and the distal end portion of the valve body and sleeve is inserted into the mounting target. Can occur.

  The present invention focuses on the above points and aims to solve such problems.

  In order to solve the above problems, a control valve according to the present invention has a configuration as described below. That is, a control valve according to the present invention is a control valve including a casing having a hydraulic circuit therein, and a relief valve provided in the hydraulic circuit and attached to the casing. A valve body having a sleeve insertion hole, a sleeve having a base end inserted into the sleeve insertion hole and having a pilot chamber therein, a pilot valve body capable of moving forward and backward within the valve body, and the pilot valve body can be seated A pilot valve portion that opens when the pressure in the pilot chamber exceeds a predetermined pressure, a main valve body that can move forward and backward within the sleeve, and the main valve body that is formed in the sleeve. A main valve that has a seatable main valve seat and opens when a pressure difference occurs between the inside and outside of the pilot chamber And a seal member provided on the inner surface of the sleeve for preventing leakage of hydraulic fluid from the inside of the pilot chamber, and preventing the sleeve from coming off when the sleeve contacts the casing. A retaining part is provided.

  In order to solve the above-described problems, the relief valve according to the present invention has the following configuration. That is, a relief valve according to the present invention includes a valve body having a sleeve insertion hole therein, a sleeve having a base end portion inserted into the sleeve insertion hole and having a pilot chamber therein, and a main valve capable of moving forward and backward within the sleeve. Body, a pilot valve body that is formed on the sleeve and the main valve body can move forward and backward in the valve body, and a pilot valve seat on which the pilot valve body can be seated, and the pressure in the pilot chamber exceeds a predetermined pressure A pilot valve portion that opens at the time, a main valve body that can move forward and backward in the sleeve, and a main valve seat that is formed on the sleeve and on which the main valve body can be seated. A main valve portion that opens when a pressure difference occurs between them, and a seal that is provided on the inner surface of the sleeve to prevent leakage of hydraulic fluid from the inside of the pilot chamber. A relief valve and a member, the distal end of the sleeve, and a retaining portion performs retaining of the sleeve by Tosawa the object the relief valve is attached.

  If the sleeve has these configurations, when the sleeve tries to move away from the valve body, the sleeve is restricted from further movement by contacting the object to which the relief valve such as the casing is attached. It is possible to prevent the seal by the seal member from being released.

  In addition, as a preferable aspect of the retaining portion, there is a protrusion provided by projecting one part of the sleeve in a direction perpendicular to the axial direction from a part adjacent to the tip side.

  Furthermore, as an example of a mode for securely attaching the sleeve to the valve body, the sleeve is attached to the valve body in a state where a male screw formed on the sleeve is screwed to a female screw formed on the valve body. There are also things.

  According to the present invention, it is possible to prevent the occurrence of a problem that the pressure in the pilot chamber is unintentionally lowered and a part of the hydraulic fluid in the cylinder port is unintentionally guided to the tank port.

The center longitudinal section showing the control valve concerning one embodiment of the present invention. The center longitudinal cross-sectional view which shows the relief valve which concerns on the same embodiment. The enlarged view of the area | region X in FIG. The center longitudinal cross-sectional view which shows the control valve containing the conventional relief valve.

  An embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the control valve C according to the present embodiment includes a casing 1, a spool valve body 2 that can slide in a spool hole 1 x provided in the casing 1, and a relief attached to the casing 1. And a valve 3.

  The casing 1 has a hydraulic circuit therein. More specifically, a hydraulic fluid supply path 1a that receives hydraulic fluid from a hydraulic fluid supply source such as a pump (not shown), a check valve 1b provided in the hydraulic fluid supply path 1a, and a tilt cylinder TS that is an actuator. A first cylinder port 1c connected to the cylinder chamber TS1 side, a second cylinder port 1d connected to the piston TS2 side of the tilt cylinder TS, and a tank (not shown) for storing hydraulic fluid And a discharge port 1e.

  As described above, the spool valve body 2 is slidable in the spool hole 1x, and from the neutral position shown in FIG. 2, the inclined position moved from the neutral position to the right side in FIG. 2, and the neutral position. The standing position moved by a predetermined amount to the left in FIG. 2 can be selectively taken. In the neutral position, there is a gap between the hydraulic fluid supply path 1a and the first and second cylinder ports 1c and 1d, and between the discharge port 1e and the first and second cylinder ports 1c and 1d. Both are cut off. In the inclined position, the hydraulic fluid supply path 1a and the first cylinder port 1c communicate with each other, and the discharge port 1e and the second cylinder port 1c communicate with each other. In the standing position, the discharge port 1e and the first cylinder port 1c communicate with the hydraulic fluid supply path 1a and the second cylinder port 1c, respectively.

  The relief valve 3 is provided in a relief valve mounting hole 1 f communicating with the cylinder ports 1 c and 1 d, and has a main valve portion 4 and a pilot valve portion 5. The relief valve 3 has a function of adjusting the pressure in the cylinder ports 1c and 1d so as not to exceed a predetermined pressure. Hereinafter, a specific configuration of the relief valve 3 will be described with reference to FIGS. 2 and 3, the mounting structure of the relief valve 3 to the first cylinder port 1c is shown, but the mounting structure of the relief valve 3 to the second cylinder port 1d is the same.

  As shown in FIG. 2, the relief valve 3 includes a valve body 6 having a sleeve insertion hole 6x therein, and a sleeve 7 having a spring chamber 7x serving as a pilot chamber inside the base end portion of the sleeve insertion hole 6x. The main valve portion 4 having a main valve body 8 and a main valve seat 9 on which the main valve body 8 can be seated, a pilot valve body 10, and a pilot valve seat 11 on which the pilot valve body 10 can be seated. And the pilot valve portion 5 formed by using a pilot valve seat member 12 having the above.

  As shown in FIG. 2, the valve body 6 has a pilot valve body accommodating space 6a for accommodating the pilot valve element 10 so as to be able to advance and retreat in the base end side, and in the inside on the distal end side. The sleeve insertion hole 6x for housing the proximal end portion of the sleeve 7 is provided. An internal thread groove 6b for screwing the sleeve 7 is formed on the inner surface of the base end side of the sleeve insertion hole 6x, and the outer surface of the distal end portion of the valve body 6 is formed on the outer surface of the casing 1. A male screw 6c is provided for screwing into a female screw hole 1g formed in the inner surface of the relief valve mounting hole 1f.

  As shown in FIG. 2, the sleeve 7 has a hydraulic fluid inlet 7a communicating with the cylinder ports 1c, 1d at the tip, that is, the end toward the cylinder ports 1c, 1d, and the discharge port on the side surface. It is a cylindrical member having a hydraulic fluid discharge port 7b communicating with 1e. A male screw 7 c is provided at the base end portion of the sleeve 7 so as to be screwed into the female screw groove 6 b of the valve body 6 and screw the sleeve 7 into the valve body 6. That is, the sleeve 7 is attached to the valve body 6 in a state where the male screw 7c is screwed into the female screw groove 6b. The inside of the sleeve 7 is a spring chamber 7x in which a main poppet 14 constituting the main valve body 8 of the main valve portion 4 can slide. The main valve seat 9 is formed at the upstream end edge of the spring chamber 7x.

  As described above and as shown in FIG. 2, the main valve portion 4 includes the main valve body 8 and the main valve seat 9 on which the main valve body 8 can be seated and formed on the sleeve 7. It is formed using. The main valve portion 4 is configured such that the main valve body 8 is opened away from the main valve seat 9 when a pressure difference is generated between the inside and the outside of the spring chamber 7x. The main valve body 8 is a member composed of an intermediate piston 13 having a back pressure chamber 13a opened on the side opposite to the side facing the main valve seat 9, and a main poppet 14 housing the intermediate piston 13 therein. And an orifice 8x that communicates the back pressure chamber 13a and the cylinder ports 1c, 1d. The main valve portion 5 selectively takes a valve closing state in which the main poppet 14 is seated on the main valve seat 9 and a valve opening state in which the main poppet 14 is separated from the main valve seat 9. More specifically, the main valve body 8, that is, the intermediate piston 13 and the main poppet 14 are directed toward the main valve seat 9 between the intermediate piston 13 of the main valve body 8 and the pilot valve seat member 12. A first spring 15 is provided as biasing means for biasing. When the pilot valve portion 5 is opened and a differential pressure is generated between the spring chamber 7x and the cylinder ports 1c and 1d, the main valve portion 4 is caused by the differential pressure. The force acting on the body 8 overcomes the urging force of the spring 15 and takes the valve open state.

  As described above and as shown in FIG. 2, the pilot valve portion 5 includes a pilot valve body 10 capable of moving forward and backward in the pilot valve body storage space 6 a of the valve body 6, and the pilot valve body 10. A pilot valve seat member 12 having a seatable pilot valve seat 11 is used. The pilot valve section 5 is configured such that the pilot valve body 10 is opened away from the pilot valve seat 11 when the pressure in the spring chamber 7x exceeds a predetermined pressure. The pilot valve body 10 has a substantially conical valve body 10a having a diameter that decreases toward the cylinder ports 1c and 1d, and a side opposite to the side from the valve body 10a toward the cylinder ports 1c and 1d. And a guide portion 10b that slides in the pilot valve body storage space 6a. On the other hand, the pilot valve seat member 12 has a flange 12a disposed between the sleeve 7 and the valve body 6, and extends from the flange 12a toward the cylinder ports 1c and 1d to the inside of the sleeve 7. And a pilot valve seat 11 at the end of the mounting portion 12b opposite to the side facing the cylinder ports 1c and 1d. The pilot valve section 5 selectively selects a closed state in which the pilot valve body 10 is seated on the pilot valve seat 11 and a opened state in which the pilot valve body 10 is separated from the pilot valve seat 11. Take. More specifically, it is a biasing means that biases the pilot valve body 10 toward the pilot valve seat 11 between the valve body 10a of the pilot valve body 10 and the valve body 6. The spring 16 is provided. When the hydraulic pressure introduced into the spring chamber 7x from the cylinder ports 1c and 1d through the orifice 8x of the main valve body 8 exceeds a predetermined value, the pilot valve portion 5 is caused by this hydraulic pressure. The force acting on 10 overcomes the urging force of the second spring 16 and takes the valve open state.

  In order to prevent leakage of hydraulic fluid from the spring chamber 7x between the valve body 6 and the sleeve 7, more strictly between the pilot valve seat member 12 and the sleeve 7, O. A seal member 17 using a ring is disposed.

  In addition, in this embodiment, as shown in FIGS. 2 and 3, the sleeve 7 is provided with a retaining portion 18 at the distal end portion.

  The retaining portion 18 expands the diameter of the portion on the proximal end side of the sleeve 7 more than the portion adjacent to the distal end side. In other words, the portion on the proximal end side of the sleeve 7 is adjacent to the distal end side. It is the protrusion provided by making it protrude in the direction orthogonal to an axial direction rather than the site | part to do.

  In such a case, the sleeve 7 rotates in the direction in which the screwing to the valve body 6 is loosened due to fluid pressure or the like, and in the direction of the arrow Y in FIG. Even in the case of movement, as shown by the imaginary line in the figure, the further movement of the sleeve 7 is restricted when the retaining portion 18 contacts the casing 1.

  Therefore, according to the configuration of the present embodiment as described above, movement of the sleeve 7 in the direction in which the sleeve 7 is removed from the valve body 6 is restricted by the retaining portion 18. The state in which the seal member 17 is sandwiched between the pilot valve seat member 12 is released by largely moving in the direction in which it is removed from the valve, and the occurrence of problems due to leakage of hydraulic fluid from the spring chamber 7x is prevented. be able to.

  The sleeve 7 is attached to the valve body 6 in a state where the male screw 7c formed on the sleeve 7 is screwed into the female screw groove 6b formed on the valve body 6. It can be securely attached to the valve body 6.

  The present invention is not limited to the embodiment described above.

  For example, the main valve portion is not limited to the intermediate piston and the main poppet as in the above-described embodiment, but the main valve portion is integrally formed, in other words, a back pressure chamber is provided inside the main poppet and this You may employ | adopt the structure which provides the orifice which connects a back pressure chamber and a cylinder port.

  The pilot valve seat member of the pilot valve portion may be of any shape and configuration as long as it is fixed to the body and has a pilot valve seat.

  In addition, in the embodiment described above, the retaining portion is formed by projecting one portion of the sleeve in a direction perpendicular to the axial direction relative to the portion adjacent to the distal end side. Any shape can be used as long as it can prevent the body from being pulled out. For example, the outer diameter of the sleeve is gradually increased toward the base end side, that is, the side closer to the body, and when the sleeve moves in a direction to be removed from the body, a part of the outer surface of the sleeve comes into contact with the casing. An embodiment is conceivable. Further, a retaining portion may be provided on the casing side instead of the sleeve.

  In addition, in the embodiment described above, the sleeve is screwed to the body so that the sleeve can be fixed to the body more easily and reliably. May be simply inserted into the body.

  The configuration of the relief valve according to the present invention is not only for controlling the pressure in the cylinder port below a predetermined value, but also for the pressure at a certain location in the hydraulic circuit provided in the hydraulic circuit. The present invention can be applied to all relief valves provided for the following control.

  In addition, various modifications may be made without departing from the spirit of the present invention.

C ... Control valve 1 ... Casing 3 ... Relief valve 4 ... Main valve 5 ... Pilot valve 6 ... Valve body 7 ... Sleeve 7x ... Pilot chamber (spring chamber)
DESCRIPTION OF SYMBOLS 8 ... Main valve body 9 ... Main valve seat 10 ... Pilot valve body 11 ... Pilot valve seat 17 ... Sealing member 18 ... Detachment part

Claims (4)

A control valve comprising a casing having a hydraulic circuit therein and a relief valve provided in the hydraulic circuit and attached to the casing;
The relief valve includes a valve body having a sleeve insertion hole therein, a sleeve having a base end portion inserted into the sleeve insertion hole and having a pilot chamber therein, a pilot valve body capable of moving forward and backward in the valve body, and A pilot valve seat, on which a pilot valve body can be seated, is formed on the pilot valve portion that opens when the pressure in the pilot chamber exceeds a predetermined pressure, and the main valve body that can move forward and backward in the sleeve and the sleeve A main valve seat that can be seated by the main valve body, and that opens when a pressure difference occurs between the inside and the outside of the pilot chamber; and the pilot provided on the inner surface of the sleeve And a sealing member for preventing leakage of hydraulic fluid from the inside of the chamber, and the sleeve comes into contact with the casing to prevent the sleeve from coming off. Control valve which is provided with a retaining portion carried out. 2. The control valve according to claim 1, wherein the retaining portion is a protrusion provided by projecting one part of the sleeve in a direction perpendicular to the axial direction from a part adjacent to the tip side. The control valve according to claim 1 or 2, wherein the sleeve is attached to the valve body in a state in which a male screw formed on the sleeve is screwed to a female screw formed on the valve body. A valve body having a sleeve insertion hole therein; a sleeve having a base end inserted into the sleeve insertion hole and having a pilot chamber therein; a main valve body capable of moving forward and backward in the sleeve; A pilot valve body capable of moving forward and backward within the valve body, and a pilot valve seat on which the pilot valve body can be seated, and a pilot valve portion that opens when a pressure in the pilot chamber exceeds a predetermined pressure; A main valve body capable of moving forward and backward in the sleeve and a main valve seat formed on the sleeve on which the main valve body can be seated, and when a pressure difference is generated between the inside and the outside of the pilot chamber A relief valve comprising: a main valve portion that opens; and a seal member that is provided on an inner surface of the sleeve and prevents leakage of hydraulic fluid from the inside of the pilot chamber. Te,
A relief valve provided with a retaining portion that prevents the sleeve from coming off by touching an object to which the relief valve is attached at the tip of the sleeve.

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