JP2525772B2 - Diaphragm type pilot operated directional valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to a directional control valve that directly opens and closes a flow path by a pilot pressure exerted on a diaphragm to convert a flow direction of a fluid.

"Prior Art and Its Problems" This type of directional control valve has the basic structure of US Pat.
Proposed by No. 6,605. FIG. 5 to FIG. 9 show an example thereof. First, the operating principle of this directional control valve will be explained based on this figure.

This directional valve is a diaphragm that doubles as a gasket.
It has a flow path block 20 and a control block 10 divided by 11, and a single supply port 22 for receiving a pressure fluid (pressurized air) from a pressure fluid source P and a pair of load ports in this flow path block 20. 25 and the discharge port are open.

The pair of separation passages 23 separated from the supply port 22 communicate with the pair of annular passages 24, respectively. Load port 25
Is opened in the center of the annular passage 24, and the discharge port 27 is opened in the center of the annular passage 26 communicating with the load port 25. The annular passage 24, the load port 25, the annular passage 26, and the discharge port 27 are opened at the end surface on the control block 10 side and face the diaphragm 11. The load port 25 is connected to the actuator A, and the discharge port 27 is open to the atmosphere.

The illustrated actuator A is a cylinder device, and the load ports 25 of the left and right flow path switching valve portions 21 communicate with the cylinder chambers S1 and S2 defined by the piston P, respectively.

The peripheral edges of the load port 25 and the discharge port 27 are a valve seat 25s and a valve seat 27s with which the diaphragm 11 contacts and separates, respectively. Reference numeral 12 is a grid (mesh) that prevents the diaphragm 11 from being deformed into the load port 25 (exhaust port 27) due to the pressure difference between the front and back sides thereof.

Control block 10 includes load port 25 and exhaust port
Pilot pressure passages 31 and 32 are opened so as to face the center of 27. The diaphragm 11 has a flow passage block when the pilot pressure control device 33 applies a pilot pressure p higher than a certain pressure to the pilot pressure passages 31, 32.
It transforms to the 20 side. Therefore, when the pilot pressure p is applied to the pilot pressure passage 31, the communication between the supply port 22 and the load port 25 is cut off, and when the pilot pressure p is applied to the pilot pressure passage 32, the load port 25 and the discharge port are released. 27 communication is cut off. Therefore, by controlling the supply of the pilot pressure p to the pilot pressure passages 31 and 32 by the pilot pressure control device 33, it is possible to control the supply of the fluid to the actuator A as shown in FIGS. 5 to 8.

That is, in FIGS. 5 to 8, the pilot pressure passage 31 or 32, to which the symbol p is attached, is applied with the pilot pressure p, and the passage not attached is open to the atmosphere. As is clear from the open / closed states of the flow paths shown in these figures, the piston P moves to the right in the state of FIG. 5 and the same to the left in the state of FIG. 6, and the states of FIG. 7 and FIG. Will stop at. In the state shown in FIG. 7, since the pressure fluid is supplied to both the cylinder chambers S1 and S2, the piston P
Although it does not move even if force is applied to it, in the state of FIG. 8, both the cylinder chambers S1 and S2 communicate with the discharge port 27,
The piston P can be moved freely.

The directional control valve having the above operation principle has excellent features such as no sliding portion, therefore no lubrication is required, a large flow rate can be flown, and precision machining is unnecessary and workability is good. is there. However, in this directional control valve, the diaphragm 11 has to be operated at two points, that is, at the center of the load port 25 and at the center of the discharge port 27 for each set of the supply port 22, the load port 25, and the discharge port 27. There is a problem of increasing the size.

"Object of the Invention" The present invention focuses on this problem, and an object thereof is to obtain a diaphragm-type pilot operated directional control valve structure that can be further downsized.

[Outline of the Invention] The present invention has been completed based on the idea that the positions of the passages of the respective ports to be opened to the control block side end surface of the flow path block can be made smaller by concentrically arranging them. It was done.

The present invention includes a flow path block; a control block; a diaphragm sandwiched between the flow path block and the control block;
A first port (corresponding to the above-mentioned supply port), a second port (same load port), and a third port (same discharge port) formed in the flow path block; A central hole formed by opening the end face on the control block side; communicating with the flow path block through the first port, the second port, and the third port respectively, and opened on the end face on the control block side outside the central hole. A first annular passage, a second annular passage, and a third annular passage, which are sequentially concentrically formed; a central valve portion defined by the diaphragm, which opens and closes between the central hole and the first annular passage, and a second annular passage. An annular valve portion that opens and closes between the third annular passages; a first pilot pressure formed in a control block that selectively applies pilot pressure to the central valve portion of this diaphragm to open and close between the central hole and the first annular passage. aisle; And a second pilot pressure passage formed in the control block for selectively applying pilot pressure to the annular valve portion of the diaphragm to open and close between the second annular passage and the third annular passage. .

"Examples of the Invention" The present invention will be described below with reference to illustrated examples. FIGS. 1 to 4 show an embodiment of the present invention. In the flow path block 40, the minimum unit of the flow path switching valve is a supply port (first port) 41, a load port (second port). 42 and a discharge port (third port) 43 are formed. Each of these ports is formed from the three surrounding surfaces of the rectangular parallelepiped flow path block 40 toward the center.
42 directly communicates with a central hole 44 formed in the center of the flow path block 40. An annular portion (supply side annular passage, first annular passage) 46 is formed around the center hole 44 via a partition wall 45, and the annular portion 46 communicates with the supply port 41. An end surface of the partition wall 45 on the control block 60 side forms a valve seat 45s.

On the end surface of the flow path block 40 on the control block 60 side, a load side annular passage (second annular passage) 47 that is concentric with the partition wall 45 is provided.
And a discharge-side annular passage (third annular passage) 48 are formed. The load side annular passage 47 is connected to the load port 42 via the communication passage 49, and the discharge side annular passage 48 is connected to the communication passage 50 (second
(FIG. 2) and communicates with the discharge port 43, respectively. Further, on the end surface of the flow path block 40 on the control block 60 side, an annular portion
Between the 46 and the annular passages 47, 48 and outside the annular passages 47, 48, there are formed bead grooves 51, 52 concentric with the annular beads 71, 72 of the diaphragm 70, respectively.

The diaphragm 70 has a circular thick wall in the center and a central valve 73
The annular portion between the annular beads 71 and 72 is the annular valve portion 74, and when the central valve portion 73 is seated on the valve seat 45s,
The communication between the supply port 41 and the load port 42 is cut off. Further, the annular valve portion 74 includes the load side annular passage 47 and the discharge side annular passage 48.
When it comes into close contact with, the communication between the load port 42 and the discharge port 43 is cut off.

The control block 60 includes the central valve portion 73 and the annular valve portion.
Corresponding to 74, the central recess 61 and an annular recess concentric therewith
62 is formed, and pilot pressure passages 63 and 64 communicate with the central recess 61 and the annular recess 62, respectively.
Only one pilot pressure passage 63 opens in the center of the central recess 61, and a plurality of pilot pressure passages 64 open around the annular recess 62. The pilot pressure supply device 65 controls the supply of pilot pressure to the pilot pressure passages 63 and 64.

Therefore, when the pilot pressure p is exerted on the pilot pressure passage 63, the main directional control valve having the above-described configuration is operated by the diaphragm.
When the central valve portion 73 of the seat 70 is seated on the valve seat 45s to cut off the communication between the supply port 41 and the load port 42 and the pilot pressure p is exerted on the pilot pressure passage 64, the annular valve portion 74 causes the load side annular passage.
The load port 42 and the discharge port 43 are disconnected from each other by closely contacting 47 and the discharge-side annular passage 48. Conversely, if the supply of pilot pressure p to the pilot pressure passages 63 and 64 is stopped, the supply port
41 and load port 42, or load port 42 and discharge port
43 will be in communication. Therefore, by controlling these pilot pressures p, the pressure from the pressure fluid source P can be supplied to the load port 42, or the pressure fluid supplied to the load port 42 can be discharged to the discharge port 43. .

In the illustrated example, the load port 42 is connected to a single pressure chamber 81 of the actuator 80. Therefore, when the load port 42 and the supply port 41 are communicated with each other and the communication between the load port 42 and the discharge port 43 is cut off at the same time, the piston 82 is compressed by a compression spring.
When the load port 42 and the supply port 41 are disconnected from each other and the load port 42 is connected to the discharge port 43, the piston 82 can be restored by the force of the compression spring 83.

The directional control valve of the present invention has an advantage that the flow rate, especially between the load side annular passage 47 and the discharge side annular passage 48, can be made large in addition to the advantage that it can be made compact. That is, the diameter D of the load side annular passage 47 (exhaust side annular passage 48) located concentrically with the partition wall 45 and the annular portion 46 is sufficiently larger than the diameter d of the partition wall 45. The flow passage area can be secured to a large extent by the annular valve portion 74 of the diaphragm 70 being slightly separated from the load side annular passage 47 (discharging side annular passage 48). Therefore, it is possible to flow a large flow rate while being small.

In the present invention, the specific configuration of pilot pressure control device 65 for exerting pilot pressure on pilot pressure passage 63 or 64 does not matter.

In the above embodiment, the present invention is shown in the simplest form.
If the pair of load ports 42 and discharge ports 43 are provided in common with 41 as described above, the piston is moved to the right and left, and stopped just like the directional control valve described in FIGS. 4 to 8. It is possible to obtain a directional control valve that can be operated.

Further, in the above embodiment and claims, ports 41, 4
2 and 43 are called a supply port, a load port, and a discharge port, respectively, but this is an expression for ease of understanding.In short, the second port 42 is replaced with the first port 41 or the third port 43. The present invention can be used as a valve that communicates alternatively or simultaneously.

[Advantages of the Invention] As described above, the present invention relates to the first, second, and third ports formed in the flow path block, and communicates with each of these ports to open the control block side end face. The second and third annular passages and the central hole communicating with the second port are concentrically arranged, and the center of the diaphragm is located between the central hole and the first annular passage and between the second annular passage and the third annular passage, respectively. Since the valve portion and the annular valve portion are opened and closed, respectively, the diaphragm type pilot operation direction switching valve can be downsized. That is, the flow path block and the control block can be downsized, the diaphragm can be downsized and the shape can be simplified, and the assemblability can be improved. Furthermore, the diameter of the annular passage on the outer peripheral side is inevitably increased. It is possible to obtain a large flow passage area by various movements, and it is possible to obtain a directional switching valve that is small in size and can flow a large flow rate.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a diaphragm type pilot operated directional control valve of the present invention in which the right half and the left half are opened differently, FIG. 2 and FIG. 3 are FIG. II-
Sectional views taken along line II and III-III, FIG. 4 is a plan view of the diaphragm showing the central recesses, annular recesses, and pilot pressure passages of the control block in alignment with each other. FIGS. FIG. 9 is a cross-sectional view of the target directional control valve in different operating states, and FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 40 ... flow path block, 41 ... supply port, 42 ... load port, 43 ... discharge port, 44 ... center hole, 45 ... bulkhead,
45s ... valve seat, 46 ... annular part (supply side annular passage), 47 ...
… Load side annular passage, 48 …… Discharge side annular passage, 49, 50 ……
Communication passage, 51, 52 …… Bead groove, 60 …… Control block, 61
...... Center recess, 62 …… Annular recess, 63, 64 …… Pilot pressure passage, 70 …… Diaphragm, 71, 72 …… Annular bead,
73 …… Central valve part, 74 …… Annular valve part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toichi Aoki 1-chome, Mitsuhashi, Omiya-shi 840 Fujikura Rubber Industrial Co., Ltd. Omiya factory (72) Inventor Takashi Ejiri 3-13-16 Nakano, Nakano-ku, Tokyo (72) Invention Person Masao Kojima 1-34-19 Ohara, Setagaya-ku, Tokyo

Claims (1)

(57) [Claims] 1. A flow path block; a control block; a diaphragm sandwiched between the flow path block and the control block; a first port, a second port formed in the flow path block;
And a third port; a central hole formed in the flow path block so as to communicate with the second port and open at the end surface on the control block side; the flow path block, the first port, the second port, and A first annular passage, a second annular passage, and a third annular passage, which are respectively communicated with the third ports and opened on the end surface on the side of the control block and are sequentially formed concentrically outside the central hole; A central valve portion that opens and closes between the central hole and the first annular passage, and an annular valve portion that opens and closes between the second annular passage and the third annular passage, which are selectively formed on the central valve portion of the diaphragm. The first pilot pressure passage formed in the control block to open and close between the center hole and the first annular passage by selectively applying a pilot pressure to the annular valve portion of the diaphragm. Diaphragm pilot operated directional control valve, characterized in that it comprises a; serial second annular passage and the third opening and closing between the annular passage, the second pilot pressure passage formed in the control block.