JP3763184B2 - Switching valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a switching valve used in a fluid pressure circuit such as oil or air.
[0002]
[Prior art]
A switching valve is used for control to switch the circuit configuration of a fluid circuit such as oil or air.
The switching valve includes a valve housing to which a plurality of fluid pipes and passages (hereinafter referred to as fluid passages) are connected, and a valve shaft member fitted in the valve housing so as to be movable in the axial direction. Depending on the relationship between the outer peripheral shape of the member and the inner peripheral shape of the valve housing, by changing the axial position of the valve shaft member relative to the valve housing, the continuity relationship between the plurality of fluid flow paths introduced into the valve housing is changed. This valve shaft member can be operated by operating means (for example, solenoid of solenoid valve, lever or button of man-powered valve, cam or link mechanism of mechanically operated valve, etc., to change the axial position relative to the valve housing. Thus, the switching control of the target circuit configuration is realized.
[0003]
By the way, the “poppet valve type” and the “spool valve type” are known as the basic structure principle of the switching valve that switches the circuit configuration according to the axial position of the valve shaft member.
FIG. 6 shows the structure of a spool valve type 2-position 4-port switching valve.
The spool valve 100 includes a valve housing 110 having four ports 131, 132, 133, and 134 and a spool 150 that slides in a fluid passage 120 in the valve housing 110. The spool 150 includes two land portions 151 and 152, and annular groove portions 153, 154, and 155 disposed on both sides of the land portions 151 and 152. In the state of FIG. 4, the port 131 and the port 134 are communicated, and the port 132 and the port 133 are communicated.
When the spool 150 is moved in the direction of arrow R in the figure, the land 151 closes the inner peripheral portion 122 of the fluid passage 120. By this action, the port 131 and the port 133 are communicated, and the port 132 and the port 134 are communicated.
[0004]
FIG. 7 shows the structure of a poppet type 2-position 3-port switching valve.
The poppet valve 200 includes a housing 210 having three ports 211, 212, and 213 and a spool 250 that slides in a fluid passage 220 in the housing. The spool 250 has a land portion 251, and the land portion 251 selectively abuts against the wall surfaces 221 and 222 defining the fluid passage 220 of the housing 210 to perform sealing.
[0005]
In the state of FIG. 7, the port 211 and the port 213 communicate with each other. In FIG. 6, when the spool 250 is moved in the arrow L direction, the land 251 seals the wall surface 221, and the port 212 and the port 213 are communicated.
In this poppet valve, the contact mechanism between the fluid circuits is applied in addition to the contact between the members in the axial direction by the operation means of the valve shaft member, and in some cases the pressure of the fluid is applied to the contact between the members. Due to the self-sealing effect that strengthens, there is an advantage that an almost complete blocking state can be configured.
This type of poppet valve is disclosed in, for example, Japanese Patent Application Laid-Open No. 60-196471.
[0006]
[Problems to be solved by the invention]
In the above “spool valve type” switching valve, the number of ports is not limited, and various fluid flow paths can be connected to each other. For example, in a hydraulic circuit as shown in FIG. The flow path of the hydraulic circuit can be easily controlled by using one 2-position 4-port switching valve illustrated in FIG. 6 which is a typical spool valve type switching valve.
However, in the spool valve type, the fluid circuits are separated from each other by a land fitting area between the inner peripheral surface of the valve housing and the outer peripheral surface of the valve shaft member existing between the annular grooves. The diameter of the part requires a minimum clearance to allow axial sliding of the valve shaft member relative to the valve housing.
[0007]
For this reason, it is impossible to make the continuity relationship between the fluid flow paths completely cut off. Especially when there is a large pressure difference between the adjacent fluid flow paths, There is an inconvenience that the fluid leaks from the high pressure side to the low pressure side through the gap in the fitting area.
Therefore, in a system that dislikes leakage flow between the fluid flow paths, this spool valve type cannot be adopted, and it is necessary to use a poppet valve type. That is, when the 2-position 3-port switching valve illustrated in FIG. 7 which is a typical poppet valve type switching valve is used, the cutoff state of the continuity relationship between the fluid flow paths is the axial direction between the valve shaft member and the valve housing. Since this is performed by the contact relationship (at the opening surface of the fluid flow path), a complete blocking state is realized.
[0008]
However, on the principle that the shut-off state is constituted by the axial contact between the valve members, the structure in which two or more contact portions in the axial direction are simultaneously brought into contact simultaneously in both valve members is difficult in the work of the valve member. Even if it is realized, the productivity is poor and the production cost is high. Therefore, the number of ports of the fluid flow path that can be switched by the movement of one valve shaft member is as shown in FIG. The number of ports is limited to 3 ports. If the contact portions at a plurality of locations of both valve members are not completely contacted simultaneously, there is no advantage over the spool valve type.
[0009]
However, if there are 3 ports, for example, as shown in FIG. 5, it is necessary to use two 2-position 3-port switching valves illustrated in FIG. 7 in the hydraulic circuit, the hydraulic circuit itself becomes complicated, and the spool valve type This leads to an increase in production costs and the number of maintenance inspections.
An object of the present invention is to provide a switching valve that eliminates the disadvantages of the spool valve type and the poppet valve type as described above.
[0010]
[Means for Solving the Problems]
The main point of the present invention is that the floating ring member is fitted together with the floating ring member so as to be movable in the axial direction in the valve housing.
That is, the switching valve of the present invention includes, as basic means, a housing member, a valve shaft member that can move in the axial direction within the housing member provided inside the housing member, and a valve shaft member that can move in the axial direction. An externally fitted floating ring-shaped member, a main valve chamber and a sub-valve chamber in a housing member and partitioned by a partition, a first chamber at both ends in the main valve chamber and partitioned by a valve shaft member, Three chambers and an intermediate second chamber, a pressure fluid supply port formed on the wall surface of the housing member of the second chamber, a first flow port formed on the wall surface of the housing member of the first chamber, and a housing of the third chamber A second communication port formed in the member wall surface, a discharge port formed in the housing member wall surface of the sub valve chamber, and a passage communicating the main valve chamber and the sub valve chamber formed in the valve shaft member are provided.
Then, by the axial movement of the valve shaft member and the floating ring member, one of the first and second flow ports is switched to a position communicating with the pressure fluid supply port and the other is communicated with the discharge port.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A switching valve according to an embodiment of the present invention will be described with reference to the drawings.
The vertical and horizontal directions in the following description are directions in the drawings.
The switching valve in the embodiment of the present invention is a poppet valve type two-position four-port switching valve, and the working fluid to be controlled is gas or fluid, and will be described as oil in the following description. The switching valve is used, for example, in the fluid pressure circuit shown in FIG.
In the hydraulic circuit shown in FIG. 5, a poppet valve type two-position four-port switching valve V is connected to a double-acting cylinder A as an actuator and a pump P / oil tank T as an operation supply source through pipes L1 to L4. Has been.
[0012]
The two-position four-port switching valve according to the first embodiment shown in FIGS. 1 and 2 includes a valve housing 1, a valve body 2 that is slidably fitted to the valve housing 1, and an outer peripheral surface of the valve body 2. And a floating ring member 3 slidably fitted to the left and right.
The valve housing 1 is formed with a hollow hole surrounded by the peripheral wall portion 4 and the end wall portions 5 and 5 at both ends, and the valve chamber is formed between the main valve chamber and the sub valve chamber 8 blocked by the intermediate wall portion 6. The main valve chamber is divided into a first chamber 9 on the end wall portion 5 side, a third chamber 10 on the intermediate wall portion 6 side, and an intermediate second chamber 11.
[0013]
A first flow port 12 that communicates with the first chamber from the outside, a second flow port 13 that communicates with the third chamber 10, and a pressure fluid supply port 14 that communicates with the second chamber 11 pass through the peripheral wall portion 4. Further, a discharge port 15 communicating with the auxiliary valve chamber 8 from the outside passes through the peripheral wall portion 4.
[0014]
For example, the pressure fluid supply port 14 is connected to a pipe L1 from a pump P which is a hydraulic oil supply source of the hydraulic circuit shown in FIG. 5, and the discharge port 15 is also connected to a pipe L2 to the oil tank T. ing.
Further, for example, a pipe L3 from one port a of a double acting cylinder A which is an actuator of a hydraulic circuit shown in FIG. 5 is connected to the first circulation port 12, and the other port is similarly connected to the second circulation port 13. Pipe line L4 from b is connected.
[0015]
The valve shaft member 2 includes a first valve rod portion 16, a first flange portion 17, a cylindrical intermediate portion 18, a second flange portion 19, and a second valve rod portion 20, and includes a first chamber 9 and a third chamber. The first flange portion 17 and the second flange portion 19 having a diameter smaller than 10 are in the main valve chamber, and the first valve rod portion 16 penetrates the end wall portion 5 of the valve housing 1 in a slidable and oil-tight manner. The second valve rod portion 20 penetrates the intermediate wall portion 6 and the end wall portion 5 of the valve housing 1 in a slidable and oil-tight manner and protrudes to the outside.
The first valve rod portion 16 is coupled with operating means such as a solenoid of a solenoid valve (see FIG. 5), a lever of a manual operation valve, a mechanical operation cam, a link mechanism, and the like.
[0016]
A first annular groove 21 and a second annular groove 22 are formed at both ends of the intermediate portion 18 of the valve shaft member 2, and the first axis from the end of the second valve rod portion 20 is the center axis of the valve shaft member 2. A center hole 23 reaching the position of the annular groove 21 is formed, and the open end of the center hole 23 on the second valve rod portion 20 side is closed. And the 1st communicating hole 24 and the 2nd communicating hole 25 which each connect the center hole 23 and the 1st annular groove 21 and the 2nd annular groove 22 are formed, and the center hole 23 and the subvalve chamber 8 are made into. A third communication hole 26 that always communicates is formed.
[0017]
A floating ring member 3 shorter than the intermediate portion 18 is slidably fitted to the outer peripheral surface of the intermediate portion 18 of the valve shaft member 2, and the length of the floating ring member 3 is positioned at both end positions of the intermediate portion 18. In this case, the length is such that it does not cover the first annular groove 21 or the second annular groove 22.
The floating ring member 3 is appropriately larger in diameter than the first chamber 3 and the third chamber 10 and smaller in diameter by an appropriate gap 27 than the second chamber 11.
Therefore, both end surfaces of the floating ring member 3 and both end surfaces of the second chamber 11 can be in contact with each other by forming an appropriate contact surface.
[0018]
The operation of the two-position four-port switching valve according to the first embodiment will be described. The valve shaft member 2 has the first valve rod portion 16 shown in FIG. 1 by an operating means, for example, a solenoid of a solenoid valve (see FIG. 5). The position is switched to the two positions of the position shown in FIG. 2 and the position shown in FIG.
When the valve shaft member 2 moves left to the position shown in FIG. 1, the floating ring member 3 is pushed left by the second flange portion 19, and the outer peripheral area of the left end surface of the floating ring member 3 is the second chamber 11. The inner peripheral area of the left end face is in close contact with the inner peripheral area of the right end face, and the outer peripheral area of the right end face of the floating ring member 3 is in close contact with the outer peripheral area of the left side surface of the second flange portion 19. The first collar portion 17 is separated from the floating ring member 3 away from the inner peripheral region of the right end surface of the first ring portion 17.
[0019]
As a result, the first chamber is disconnected from the second chamber 11 by the floating ring member 3 and communicates with the first annular groove 21. Further, the second chamber 11 is blocked from the second annular groove 22 by the floating ring member 3 and the second flange portion 19.
That is, in the position state of the valve body (see FIG. 1), the pressure fluid supply 14 is connected to the second flow port 13 through the gap 27, the second chamber 11 and the third chamber 10, and the first The first flow port 12 is connected to the discharge port 15 through the first chamber, the first annular groove 21, the first communication hole 24, the center hole 23, the third communication hole 26, and the sub valve chamber 8.
[0020]
Thus, the hydraulic fluid supplied from the hydraulic fluid supply source (for example, the pump P in FIG. 5) of the hydraulic circuit via the pipeline L1 flows from the pressure fluid supply 14 and flows out from the second circulation port 13 to the pipeline. The hydraulic oil supplied to, for example, the port b of the double acting cylinder A, which is an actuator in the hydraulic circuit via L4, flows out from the port a of the double acting cylinder A and flows in from the first flow port 12 via the pipe L3. Then, the oil is discharged from the discharge port 15 to the oil tank T through the pipe line L2. Thereby, one operation of the double acting cylinder A is performed.
[0021]
The hydraulic oil flowing from the pressure fluid supply 14 flows into the third chamber 10 and faces the double-acting cylinder A. The hydraulic oil flowing from the first flow port 12 flows into the first chamber, and the oil tank T Therefore, the third chamber 10 is on the high pressure side, the first chamber is on the low pressure side, and the differential pressure is applied to the second flange 19 and the floating ring member 3, and the floating ring member 3 is moved to the left end of the second chamber 11. It acts as a pressing force that presses against the surface, and also serves as a pressing force that presses the second flange 19 against the right end surface of the floating ring member 3.
[0022]
Therefore, the pressing force for pressing the floating ring member 3 against the left end surface of the second chamber 11 and the pressing force for pressing the second flange portion 19 against the right end surface of the floating ring member are the valve shaft member 2 by the operating means, that is, the first pressure. 2 The pressing force by the differential pressure is added to the pressing force by the flange portion 19 so that the outer peripheral area of the left end surface of the floating ring member 3 and the inner peripheral area of the left end surface of the second chamber 11 are in close contact with each other. The close contact between the inner peripheral area of the right end surface and the outer peripheral area of the left side surface of the second flange portion 19 becomes even stronger.
[0023]
When the valve shaft member 2 moves rightward from the position shown in FIG. 1 to the position shown in FIG. 2, the valve shaft member 2 slides to the right with respect to the floating ring member 3 in a stationary state, and eventually the first flange portion 17 is moved. The floating ring member 3 is contacted and pressed to the right. Then, the outer peripheral region of the left end surface of the floating ring member 3 is separated from the inner peripheral region of the left end surface of the second chamber 11, the outer peripheral region of the right end surface is in close contact with the inner peripheral region of the right end surface of the second chamber 11, and The outer peripheral area of the right side surface of the first flange portion 17 is in close contact with the inner peripheral area of the left end surface of the floating ring member 3, and the second flange portion 19 is separated from the floating ring member 3.
[0024]
As a result, the first chamber 9 communicates with the second chamber 11 and is blocked from the first annular groove 21 by the first flange 17 and the floating ring member 3. The third chamber 10 is disconnected from the second chamber 11 by the floating ring member 3 and communicates with the second annular groove 22.
That is, in the position state of the valve body, the pressure fluid supply 14 is connected to the first flow port 12 through the gap 27, the second chamber 11 and the first chamber, and the second flow port 13 is The third chamber 10, the second annular groove 22, the second communication hole 25, the center hole 23, the third communication hole 26, and the auxiliary valve chamber 8 are connected to the discharge port 15.
[0025]
Thus, the hydraulic fluid supplied from the hydraulic fluid supply source (for example, the pump P in FIG. 5) of the hydraulic circuit via the pipeline L1 flows in from the pressure fluid supply 14, flows out of the first circulation port 12, and the pipeline The hydraulic oil that is supplied to the port a of the double acting cylinder A in the hydraulic circuit via L3 and flows out from the port b of the double acting cylinder A flows from the second circulation port 13 via the pipe L4, and is discharged. 15 is discharged to the oil tank T through the pipe line L2. Thereby, the other operation of the double acting cylinder A is performed.
For the same reason as in the case of the left row of the valve shaft member 2, the outer periphery of the right end surface of the floating ring member 3 is caused by the differential pressure between the first chamber on the high pressure side and the third chamber 10 on the low pressure side. The close contact between the region and the inner peripheral region of the right end surface of the second chamber 11 and the close contact between the outer peripheral region of the right side surface of the first flange portion 17 and the inner peripheral region of the left end surface of the floating ring member 3 become strong.
[0027]
FIG. 3 shows another embodiment of the present invention.
The switching valve 1a has a housing 4a. In this housing 4a, the switching valve 1a having a tip protruding into the sub-valve chamber 8 without the tip of the valve shaft member 2a protruding from the end wall portion 5a, the working fluid is liquid, and the discharge port 15 is substantially the same. Applicable to atmospheric pressure.
[0028]
FIG. 4 shows another embodiment of the present invention.
The switching valve 1b has a housing 4b. The housing 4b does not include a sub valve chamber, and the tip of the valve shaft member 2b protrudes from the partition wall 6a. In this switching valve, the central hole 23 of the valve shaft member 2b serves as a discharge port. This switching valve can be applied when the working fluid is air.
[0029]
【The invention's effect】
The switching valve according to the present invention is a poppet valve type in which a floating ring member is fitted on the outer peripheral surface so that the floating ring member is movable in the axial direction together with the floating ring member so as to be movable in the axial direction in the valve housing. A unique advantage is provided, and the flow path switching in the fluid flow path switching in the valve is performed completely at the contact surface in the axial direction, and the flow path switching is performed completely without leakage between the flow paths.
[0030]
At the same time, there is no difficulty in work accuracy due to simultaneous contact at a number of locations, and multi-port switching, which is an advantage unique to the spool valve type, is possible.
That is, according to the present invention, it is possible to obtain a switching valve that has only the advantages of the poppet valve type and the spool valve type and eliminates the disadvantages of both.
[0031]
Particularly in the two-position four-port switching valve according to claim 2, the first hollow portion partitioned by the floating ring member in the hollow portion of the valve housing by flowing in from the inflow hole and discharging from the outflow hole. One becomes the high pressure side, and the other hollow area becomes the low pressure side, and the differential pressure acts on the contact portion of the floating ring member and the valve body, and acts as a pressing force for pressing the floating ring member against the fixed contact portion.
Accordingly, the pressing force for pressing the floating ring member is the pressing force by the differential pressure added to the pressing force by the operating means, and the close contact between the floating ring member and each contact portion becomes even stronger.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a 2-position 4-port switching valve according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a 2-position 4-port switching valve according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view of a 2-position 4-port switching valve according to a second embodiment of the present invention.
FIG. 4 is a cross-sectional view of a 2-position 4-port switching valve according to a third embodiment of the present invention.
FIG. 5 is a hydraulic circuit diagram to which the 2-position 4-port switching valve according to the embodiment of the present invention is applied.
FIG. 6 is a sectional view of a conventional 2-position 4-port switching valve (spool valve type).
FIG. 7 is a cross-sectional view of a 2-position 3-port switching valve (poppet valve type) in the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve housing 2 Valve body 3 Floating ring member 4 Peripheral wall part 5 End wall part 6 Intermediate wall part 8 Subvalve chamber 9 1st chamber 10 3rd chamber 11 2nd chamber 12 1st flow port 13 2nd flow port 14 Pressure fluid Supply port 15 Discharge port 16 First valve rod portion 17 First flange portion 18 Intermediate portion 19 Second flange portion 20 Second valve rod portion 21 First annular groove 22 Second annular groove 23 Center hole 24 First communication hole 25 First 2 communication hole 26 3rd communication hole P Pump T Oil tank A Double acting cylinder (actuator)
a, b Ports L1-L4 pipeline

Claims (2)

A housing member;
A valve shaft member that is movable in the axial direction within the housing member provided inside the housing member;
A floating ring-shaped member externally fitted to the valve shaft member so as to be axially movable;
A main valve chamber and a sub-valve chamber in the housing member and partitioned by a partition;
A first chamber at both ends, a third chamber and a second chamber at an intermediate portion, which are in the main valve chamber and partitioned by a valve shaft member;
A pressure fluid supply port formed in the wall surface of the housing member of the second chamber;
A first flow port formed in the housing member wall surface of the first chamber;
A second flow port formed in the wall surface of the housing member of the third chamber;
A discharge port formed in the wall surface of the housing member of the auxiliary valve chamber;
A passage that communicates the main valve chamber and the sub-valve chamber formed in the valve shaft member;
Two-position four-port direction characterized by switching one of the first and second flow ports to a pressure fluid supply port and the other to a discharge port by movement of the valve shaft member and the floating ring member in the axial direction Switching valve. A housing member;
A valve shaft member that is movable in the axial direction within the housing member provided inside the housing member;
A floating ring-shaped member externally fitted to the valve shaft member so as to be axially movable;
A valve chamber in the housing member and partitioned by a partition;
A first chamber at both ends separated by a valve shaft member in the valve chamber, a third chamber, and a second chamber at the intermediate portion;
A pressure fluid supply port formed in the wall surface of the housing member of the second chamber;
A first flow port formed in the housing member wall surface of the first chamber;
A second flow port formed in the wall surface of the housing member of the third chamber;
A passage having a function as a discharge port communicating with the valve chamber formed in the valve shaft member and the outside of the housing;
Two-position four-port direction characterized by switching one of the first and second flow ports to a pressure fluid supply port and the other to a discharge port by movement of the valve shaft member and the floating ring member in the axial direction Switching valve.

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