JPH0514053Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a flow path switching valve that simultaneously switches flow paths in a pair of control chambers.

"Prior Art and its Problems" FIGS. 4 to 8 show an example of a directional switching valve that requires a flow path switching valve, which is the object of the present invention. This directional control valve is an improved version of the directional control valve proposed in U.S. Pat. No. 4,516,605 to enable three-position control. (No. 127583)
are doing. First, this switching valve will be explained.

This directional switching valve has a flow path block 20 and a control block 40 separated by a diaphragm 11 which also serves as a gasket, and this flow path block 20 is provided with a pair of flow path switching sections 21. A single supply port 22 for receiving pressurized fluid (pressurized air) from a pressure fluid source (compressor) P is open in the flow path block 20. A pair of separation passages 23 separated from the supply port 22 communicate with annular passages 24 of the pair of flow path switching sections, respectively. A load port 25 opens in the center of this annular passage 24, and an annular passage 26 that communicates with this load port 25
A discharge port 27 is opened in the center. The annular passage 24, the load port 25, the annular passage 26, and the discharge port 27 are each open to the diaphragm 11 side, and the load port 25 is connected to the actuator A.
The exhaust port 27 is open to the atmosphere.

The illustrated actuator A is a cylinder device, and cylinder chambers S1 and S are partitioned by a piston p.
2 and the load ports 25 of the left and right flow path switching sections 21 are in communication with each other.

The peripheries of the load port 25 and the discharge port 27 on the control block 40 side are connected to the diaphragm 11, respectively.
constitute a valve seat 25s and a valve seat 27s that come into contact with and separate from each other. The valve seats 25s and 27s are cut down so as to be slightly apart from the diaphragm 11 which is in a flat state. Reference numeral 12 denotes a grid that prevents the diaphragm 11 from being deformed into the load port 25 (discharge port 27) due to the pressure difference between the front and back sides of the diaphragm 11.

A pilot pressure introduction path 28 is bored in the center of the supply port 22 of the flow path block 20, directly facing the flow direction of the pressure fluid from the pressure fluid source P.
This pilot pressure introduction path 28 is connected to the diaphragm 11.
It communicates with the left and right independent pilot switching valves 50 through a small hole in the control block 40, a pilot pressure introduction passage 41 on the control block 40 side, and pilot pressure introduction passages 55 and 56 branched from this introduction passage. The pressure exerted on the pilot pressure introduction path 28 is slightly higher than the pressure of the pressure fluid at the supply port 22 due to the laws of fluid dynamics. In this embodiment, this pressure is used as the pilot pressure.

The pilot switching valve (flow path switching valve) 50 has the same or symmetrical structure on the left and right sides, and has the function of selectively communicating the respective load ports 25 with the supply port 22 or the discharge port 27, and both of them can be connected independently. Since it is operable, it allows three-position control of the valve. Next, details of this pilot switching valve 50 will be explained.

Pilot pressure passages 51 and 52 are bored in the control block 40, corresponding to the center positions of the load port 25 and the discharge port 27, respectively. 54 respectively. The control chambers 53 and 54 also include a pilot pressure passage 4.
The pilot pressure passages 55, 56 branched from 1.
and atmospheric air introduction passages 57 and 58 communicating with the atmosphere are open, respectively. The tips of the pilot pressure passage 55 and the atmosphere introduction passage 57 constitute valve seats 55s and 57s facing up and down inside the control room 53, and similarly, the tips of the pilot pressure passage 56 and the atmosphere introduction passage 58 constitute the control room 53. Valve seats 56s, 5 facing up and down in 54
It constitutes 8s. Also, the pilot pressure passage 5
The opening ends of the diaphragms 1 and 52 toward the diaphragm 11 are formed as smooth arcuate surfaces 51a and 52a that extend to the annular passage 24 or the annular passage 26.

A valve arm 6 is provided in the partition between the control chambers 53 and 54.
The valve arm 60 is supported so as to be able to swing and maintain airtightness between the left and right control chambers, and valve bodies corresponding to the valve seats 55s, 57s and the valve seats 56s, 58s are provided above and below both ends of the valve arm 60, respectively. 55v, 57
v and the valve bodies 56v, 58b are fixed.

The middle part of this valve arm 60 is a solenoid 6
It is pivotally connected to a plunger 62 that reciprocates in a straight line when turning on and off. This plunger 62 is normally urged in the protruding direction by a compression spring 63, and therefore the valve arm 60 is
are urged to swing in a direction away from the valve seats 56s and 57s, respectively. At this time, the valve body 55v,
58v is seated on valve seats 55s and 58s.

On the other hand, when the solenoid 61 is energized, the plunger 62 overcomes the force of the compression spring 63 and is retracted, and as a result, the valve bodies 55v, 58v are moved against the valve seat 55.
s and 58s, and the valve bodies 56v and 57v are removed from the valve seats 56s and 57s.

According to the above-described directional control valve, the pilot switching valve 50 can be controlled independently on the left and right sides, so that in addition to moving the piston to the right and left, the piston can also be stopped.
Position control is possible.

FIG. 4 shows a case where the piston p is moved to the right, and the solenoid 61 on the left side of the figure is turned off and the solenoid 61 on the right side of the figure is turned on. In this state, as is clear from the figure, the left pilot switching valve 50
The valve arm 60 has its valve bodies 55v, 58v seated on the valve seats 55s, 58s, and the valve bodies 56v, 57
v is separated from the valve seats 56s and 57s. Therefore, atmospheric pressure is introduced into the control chamber 53 through the air introduction passage 57, and pilot pressure is introduced into the control chamber 54 through the pilot pressure passages 56 and 28, resulting in the pilot pressure. Then diaphragm 1
1 receives pilot pressure on the back surface of the valve seat 27s and sits on the valve seat 7s, cutting off communication between the discharge port 27 and the annular passage 26. On the other hand, since the back surface of the valve seat 25s is at atmospheric pressure, the valve seat 25s
The supply port 22 and the load port 25 are communicated apart from each other.

On the other hand, the valve arm 60 of the right pilot switching valve 50 has its valve body 56v,
57v on the valve seats 56s and 57s, and the valve body 5
5v and 58v are removed from the valve seats 55s and 58s, the control chamber 53 is at pilot pressure and the control chamber 54 is at atmospheric pressure. Yotsute diaphragm 11
sits on the valve seat 25s to cut off communication between the load port 25 and the supply port 22, and leaves the valve seat 27s to communicate the load port 25 with the annular passage 26. Due to the above opening/closing relationship, the pressure fluid supplied from the pressure fluid source P to the supply port 22 flows from the left load port 25 to the cylinder chamber S1 of the actuator A, so that the piston p moves to the right. Siridan room S
The working fluid No. 2 flows from the right load port 25 to the discharge port 27 and is released to the atmosphere.

FIG. 5 shows a case where the piston p is moved to the left, and the relationship between the left and right pilot switching valves 50 is opposite to that in FIG. 3, with the left solenoid 61 on and the right solenoid 61 off. .

Solenoid 61 of left and right pilot switching valve 50
Fig. 6 shows a case where both are turned off, and Fig. 7 shows a case where both are turned on. In the state shown in FIG. 6, pressure fluid is introduced into both cylinder chambers S1 and S2, so in the case of both rod cylinders, the piston p stops, and in the state shown in FIG. Since the supply of pressure fluid to is cut off, the piston p similarly stops and becomes free to move left and right.

Directional switching valves with the above operating principle have excellent features such as no sliding parts, no need for lubrication, large flow capacity, no need for precision machining, and good workability. There is. However, in order to operate the pilot switching valve (flow path switching valve) 50, the valve arm 60 must be swung while maintaining the confidentiality of the control chambers 53 and 54, and the valve body 55v to 58v must be secured. aisle 55
There is a high requirement for airtightness, such as the need to open and close the parts 1 to 58, and it has therefore been difficult to achieve this with a simple structure.

``Purpose of the invention'' The present invention provides a flow path switching valve that has a simple structure and can reliably switch the flow paths in a pair of control rooms while maintaining airtightness, as described above. The purpose is to obtain. Another object of the present invention is to obtain a flow path switching valve that has a small number of parts and is easy to assemble.

"Summary of the invention" The flow path switching valve of the invention has a pair of control chambers defined by an upper case and a lower case, and is sandwiched between the upper case and the lower case to maintain airtightness of the pair of control chambers. a support ring made of a series of elastic bodies; a first passage and a second passage formed at opposing positions on the walls of the upper case and the lower case, respectively, and opening into the pair of control chambers; A third passageway opening into each chamber, a valve arm that is swingably inserted and supported at an intermediate position in the thickness direction of the support ring, and whose both ends face into the pair of control chambers, and both ends of this valve arm. a valve body that is provided in the valve arm and selectively approaches or separates from the first passage or the second passage to open and close the same according to the swinging position of the valve arm; The valve body of the part is selectively brought into elastic contact with the first passage or the second passage in the pair of control chambers, and the third passage opening into the pair of control chambers is brought into contact with the second passage or the second passage. The present invention is characterized by comprising a flow path switching means that selectively communicates with one of the passages.

``Embodiments of the invention'' The invention will be described below with reference to illustrated embodiments. 1 and 2 show an embodiment of the flow path switching valve 50 of the present invention, and the same parts as the flow path switching valves in FIGS. 4 to 7 are given the same reference numerals. . The control chambers 53 and 54 are formed by a top case 70 and a lower case 71, and a support ring 72 made of a thick elastic body is sandwiched between the top case 70 and the lower case 71 on the side of the control chamber 54. There is. The support ring 72, as shown in plan view in FIG. By clamping with 71, the control room 5
3 and 54 are kept airtight.

This support ring 72 has an annular portion 72a and a
A valve arm 74 is inserted and supported in an airtight state at the intermediate portion in the thickness direction of the connecting portion 72c of FIG. To maintain airtightness, for example, the valve arm 74 may be glued to the insertion hole of the support ring. This valve arm 74 can swing due to the elasticity of the support ring 72. Both ends of this valve arm 74 extend into the control chamber 53 and the control chamber 54,
A valve body 76 is fixed to both ends thereof. This valve body 76 is entirely made of an elastic body, and has a pair of upper and lower hemispherical parts 77, 77, which are connected to the valve seats 55s, 55, respectively.
s and valve seats 57s and 58s. The hemispherical portion 77 can closely contact the valve seats 55s to 58s and close them when the support ring 72 is swung.

Note that airtightness between the plunger 62 of the solenoid 61 and the upper case 70 is maintained in the same manner as in the conventional structure.

The main flow path switching valve 50 having the above configuration includes a solenoid 6
1 is turned on and off, the valve arm 74 swings, and the valve bodies 76 at both ends thereof sit on or leave the valve seats 55s to 58s, similar to the devices shown in FIGS. 4 to 7. Therefore, these pilot pressure introduction passages (first passages) 55, 5 opening into the control chambers 53, 54
6 or atmospheric pressure introduction path (second path) 57, 58
Open and close the pilot pressure passage (third passage) 51.
Alternatively, the flow path switching section 21 can be operated by applying pilot pressure or atmospheric pressure to 52.

The valve arm 74 is inserted through a support ring 72, and the support ring 72 has the function of sealing the control chamber 54 and between the control chambers 53 and 54, ensuring airtightness over a long period of time. can be retained. That is, since the insertion portion of the valve arm 74 with respect to the support ring 72 can be reliably maintained airtight, even if the valve arm 74 swings, the sealing effect of the support ring 72 on the outer periphery of the control chamber 54 or the control chamber 53 is The sealing effect between 54 is not impaired.

3a and 3b show another example of the shape of the support ring 72, in which the connecting portion 7 through which the valve arm 74 is inserted is shown.
2c is formed thicker than the annular portions 72a and 72b. In this embodiment, the annular portions 72a, 7
In accordance with the level difference between the upper case 70 and the connecting portion 72c, a level difference is also formed on the abutting surfaces of the upper case 70 and the lower case 71.

In the above embodiment, the pilot pressure passages (third passage) 51, 52 are selected from the pilot pressure introduction passage (first passage) 55, 56 or the atmospheric pressure introduction passage (second passage) 57, 58. However, the connection points (functions) of these first to third passages can be changed as appropriate depending on the use of the main flow path switching valve 50.

"Effect of the invention" As described above, the flow path switching valve of the present invention has the first, second, and third passages opening in the pair of control chambers, and the third passage opening into the first and third passages. A support ring made of an elastic body defines a pair of control chambers in the upper case and the lower case, and maintains the airtightness of the pair of control chambers between the upper case and the lower case in a flow path switching valve that switches and communicates with the second passage. the first and second passages are opened at opposing positions on the walls of the upper case and lower case, and the valve arm is located at an intermediate position in the thickness direction of the support ring, with both ends thereof facing into the pair of control chambers. A valve body is provided at both ends of the valve arm to open and close the first passage or the second passage by selectively approaching and separating it, and the valve arm is swung to open and close the first passage or the second passage. The valve body is selectively brought into elastic contact with the first or second passage in the pair of control chambers, and the third passage is
The second passageway or the first passageway is selectively connected to the second passageway or the first passageway. Therefore, the third passages in the pair of control chambers can be selectively communicated with the first passage or the second passage at the same time. In particular, in the present invention, since the support ring that maintains the airtightness between the upper case and the lower case simultaneously supports the valve arm in a swingable manner, it is possible to easily maintain the airtightness of the swinging portion of the valve arm. Further, since the valve arm and the support ring are made into one member that cannot be separated before assembly, it is possible to easily obtain a highly airtight flow path switching valve that is easy to assemble with a small number of parts.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts showing an embodiment of the flow path switching valve of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3a shows an example of another shape of the support ring. Fig. 4 to Fig. 7 are plan views showing an example of a directional control valve having a flow path switching valve, which is the subject of the present invention, and showing different operations. A vertical cross-sectional view of the state, FIG. 8 is shown at - of FIG.
It is a sectional view along a line. 28, 55, 56... Pilot pressure introduction passage (first passage), 51, 52... Pilot pressure passage (third passage), 40... Control block, 50...
Flow path switching valve, 53, 54... Control room, 57, 58
...Atmosphere introduction passage (second passage), 55s, 56s,
57s, 58s...valve seat, 62...plunger,
63...Compression spring, 70...Atsupa case, 71
... Lower case, 72 ... Support ring, 74 ...
Valve arm, 76... Valve body, 77... Hemisphere.

Claims (1)

[Claims for Utility Model Registration] A pair of control chambers defined by a top case and a lower case; A series of elastic bodies sandwiched between the top case and the lower case to maintain airtightness of the pair of control chambers. a support ring; a first passage and a second passage formed at opposing positions on the walls of the upper case and the lower case, each opening into the pair of control chambers; a third passage opening respectively into the pair of control chambers; ; A valve arm is swingably inserted and supported at an intermediate position in the thickness direction of the support ring, and both ends of the valve arm face the pair of control chambers; A valve body selectively moves toward and away from the first passageway or the second passageway to open and close the passageway depending on the position; and a valve body that swings the valve arm to move the valve bodies at both ends into the pair of control chambers. The third passage opening into the pair of control chambers is selectively brought into communication with the second passage or the first passage. A flow path switching valve comprising: switching means;