JPS6117701A - Non-bleeding pilot relay - Google Patents

Abstract

PURPOSE:To eliminate any insensitive zone of the captioned relay an thereby improve reliability thereof upon its operation by constructing a plunger valve with two valve bodies arranged in parallel on the shaft of said valve having and said two valve bodies opposed to valve seats each formed separately. CONSTITUTION:To an air intake valve 20 constituted by a plunger valve formed between a pressure supply chamber 3 in which supply air pressure Psup is introduced and an output chamber 4 from which an air pressure output Pout is taken out, another second air intake valve 20B having a valve body 21 and a valve seat 22a is newly provided, so as to form the air intake valve 20 in a double- seated structure. Hereby, pressures acting on both sides of the two valve bodies 14, 21 are applied to working areas where the pressures described above become relatively equal to each other, and thereby useless working force applied to the whole plunger valve is substantially eliminated. Accordingly, an insensitive zone, say, a dead spot making troubles up to now is eliminated for improving the reliability of the captioned relay upon its operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a non-bleed type pilot relay suitable for use, for example, as an amplifier for various pneumatic instruments.

[Prior art]

In general, non-bleed type pilot relays (pilot valves) have characteristics such as low air consumption and large supply and exhaust capacities, but on the other hand, there is a dead spot called a dead spot in the flow characteristics. occurs,
When this was adopted in a pneumatic instrument, it had the disadvantage of impairing its operational stability.This can be briefly explained using the conventional example shown in Fig. 3.
The non-bleed type pilot relay, which is designated as a whole by the symbol l, has a supply pressure chamber 3, an output chamber "4, an atmosphere communication chamber 5, and an input chamber 6 in its valve body 2, and among these chambers, the supply pressure chamber" The pressure chamber 3 and the output chamber 4 communicate with each other through a through hole 8 formed in an internal partition wall 7, and the output chamber 4 and the atmosphere communication chamber 5 communicate with each other through a lower diaphragm 9, and this atmosphere communication chamber 5 and the input chamber 6 are defined by an upper diaphragm 10. An opening 11 is formed in the center of the lower diaphragm 9, and this opening 11 is located between the upper and lower diaphragms 1O99. A hole 12a is opened in a cylinder 12 which interposes therebetween and connects these parts, and is further bored on the side of this cylinder 12. A hole 12a is opened to the atmosphere communication chamber 5.

13.14 is the opening ll of the lower diaphragm 9 mentioned above;
These valve bodies 13 are valve bodies that open and close the through hole 8 of the partition wall 7.
, 14 are provided at both ends of a valve shaft 15 disposed through the through hole 8 and integrally connected to each other to constitute a plunger valve, and a bias spring 16 disposed within the output chamber 4. It is normally biased in the closing direction (upward in the figure). In addition, in the figure, P sup is the supply pressure chamber 3.
Supply air pressure introduced through the intake port 17 into the Pin
is an air pressure input such as a nozzle back pressure obtained from a nozzle flapper mechanism of a pneumatic instrument, etc., which is introduced into the input chamber 6 through the input port 18; In the air pressure output, Pa is the atmospheric pressure at which the exhaust port 5a of the atmospheric communication chamber 5 is open.

In such a configuration, when the pneumatic pressure S in input to the input chamber 6 increases, the upper tire phragm IO is pressed downward, and the lower diaphragm 9 is thereby lowered via the cylinder body 12, and its As a result, the exhaust valve constituted by the valve seat 11a at the edge of the opening 11 and the seating portion 13a of the valve body 13 is closed, while the partition wall 7
The intake valve constituted by the valve seat 8a on the side edge of the through hole 8 and the seating portion 14a of the valve body 14 is opened, and the supply air pressure P sup passes through the supply pressure chamber 6 and the output chamber 5 to the air pressure output P out Toshiso will be output.

Furthermore, when the air pressure input Pin to the input chamber 6 is reduced, the upper diaphragm 10 returns upward and the valve bodies 13 and 14 forming the plunger valve move upward under the biasing force of the bias spring 16. The aforementioned intake valve is closed and the exhaust valve is opened, and the air pressure on the output port 19 side of this pilot relay passes through this exhaust valve and is released to the atmosphere, thereby also reducing the pressure of the air pressure output P out. . Therefore, in the non-bleed type pilot relay l having such a configuration, a pneumatic pressure output P out proportional to the pneumatic pressure input P in is obtained depending on the position of the valve bodies 13 and 14 forming the plunger valve corresponding to the pneumatic pressure input P in. This made it possible.

By the way, this type of conventional non-bleed type pilot relay l has the advantages of a simple structure, low air consumption, and large supply and exhaust capacity. When the intake valve that opens and closes the chamber 4 is closed and opened, a force acts on the valve body 14 due to the pressure difference on both sides, which prevents the operation in response to the input, as shown by the broken line in Fig. 2. As is clear from the legal characteristics, a dead spot (δ: dead zone) occurs in which the pneumatic output P out proportional to the pneumatic pressure input P in cannot be obtained. This is because the pressure within the supply pressure chamber 3 acting on the valve body 14 of the plunger valve constituting the intake valve is different from the pressure within the output chamber 4 due to the difference in their acting areas, and this causes the pressure required on the entire plunger valve to be different. This is because a force is applied in the opposite direction to the movement that occurs.

If a feedback control loop of a pneumatic instrument is constructed using a non-bleed type pilot relay 1 that produces such a dead zone, the operation of the entire system becomes unstable due to the presence of this dead spot (dead zone) of the pilot relay 1. This leads to disadvantages such as a lack of reliability in operation, and it is necessary to take some countermeasures.

[Summary of the invention] The present invention has been made in view of the above circumstances, and
A plunger valve that controls the opening and closing of a pneumatic passage formed inside the plunger valve is composed of two valve bodies arranged in parallel on the valve shaft, and a through hole formed in an internal partition wall that faces each other. The simple structure of a double seat structure, which is placed opposite the valve seat on the side edge, virtually eliminates the difference in the area of action of pressure on both sides of the plunger valve, which is a problem with flow characteristics in conventional valve devices. It has become possible to eliminate dead spots (dead zones) and improve operational reliability, and this allows the original characteristics of low air consumption and large supply and exhaust capacity to be realized. The present invention provides an inexpensive non-bleed type pilot relay that can be obtained.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

Figure $1 shows an embodiment of a non-bleed type pilot relay according to the present invention. In the figure, the same or corresponding parts as those in Figure 3 mentioned above are given the same numbers and their explanations are omitted. do.

Now, according to the present invention, in the non-bleed type pilot relay l having the above-described configuration, the supply air pressure P s
Supply pressure chamber 3 into which up is introduced and pneumatic output P out
A second intake valve 20B consisting of another valve body 21 and a valve seat (22''a) is added as the intake valve 20 by a plunger valve formed between the output chamber 4 from which the As a result, this intake valve 20 (20A, 20B
) has a double sheet structure.

That is, in this embodiment, an output chamber 23 extending from the supply pressure chamber 3 to the output port 19 is newly installed on the intake port 17 side of the air pressure passage (3, , a) that communicates the intake port 17 and the output port 19.
A second pneumatic passage 24 is provided, and a second pneumatic passage 24 is provided so as to be located coaxially with the through hole 8 with respect to a second internal partition wall 25 provided opposite to the internal partition wall 7 in the middle thereof.
A through hole 22 is formed, and its side edge is connected to the valve seat 22.
A second valve body 21 facing the plunger valve is provided on the valve shaft 15 of the plunger valve in parallel with the valve body 14.

Here, what should be noted is that the intake valve 20 (2
Opening area of each boat (A I
By setting them equally so that =A2), the dead spots that were a problem in the past can be eliminated, and the flow characteristics shown by the solid line in Figure 2 can be obtained. It is. That is, the intake valve 20 (20A,
20B), two valve bodies 14, 2 constituting this
The pressure acting on both sides of the plunger valve is applied to a relatively equal area of action, and as a result, unnecessary acting force on the entire plunger valve is substantially eliminated.
It is possible to obtain smooth and appropriate valve opening and closing operations.

According to such a configuration, a dead zone called a dead spot, which has been a problem in the past, is eliminated, the operational reliability is improved, and the performance as a non-bleed type pilot relay can be exhibited.

Note that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part may be modified or changed as appropriate.

〔Effect of the invention〕

As explained above, according to the non-bleed type pilot relay according to the present invention, the plunger valve that controls the opening and closing of the pneumatic passage inside the relay is configured with two valve bodies arranged in parallel on the valve shaft, Since we created a double seat structure by arranging these valve seats opposite each other to separately formed valve seats, despite the simple and inexpensive structure, we are able to eliminate dead zones called dead spots, which have been a problem with conventional valve devices. The plunger valve, which had been a problem in operation, can be operated smoothly and stably according to the input, and this has the original characteristics of low air consumption and large supply and exhaust capacity, etc. There are various excellent effects such as making it possible to bring out the advantages such as.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing an embodiment of the non-bleed type pilot relay according to the present invention, Fig. 2 is a characteristic diagram showing its flow characteristics in comparison with the conventional example, and Fig. 3 is a schematic sectional view showing the conventional example. It is a diagram. 1-...Non-bleed type pilot relay, 2-・ψ
・Valve body, 3... Supply pressure chamber, 4... Red output chamber,
5... Atmospheric communication room, 6... Building/input room, 7...
First internal partition wall, 8... Through hole, 8a... First valve seat, 9,1011II... Diaphragm, 11...
・Fist/exhaust side opening, 12 @ @ II a cylinder, 13
．． 14--Valve body (plunger valve), 15...φ valve stem, 16--Bias spring, 17--Intake port, 18--Fist/input port, 19...ψ fist output b, 20
(20A, 20B)--Intake valve, 21--・ψ
Second valve body, ? ?・Φ・Φ second through hole, 22a...
・・Second valve seat, 23-・・Second output chamber, 24 fist・
...Second pneumatic passage, 25 fists, φ, second internal partition wall. Patent Applicant: Yamatake Honeywell Co., Ltd. Agent: Masaki Yama (and 2 others) Psuρ

Claims (1)

[Claims] The side edge of the through hole in the internal partition wall provided in the middle of the air pressure passage that communicates the intake port and the output port is used as a valve seat, and a plunger valve having a valve body seated on the valve seat is installed inside, and the head of this plunger valve is In a non-bleed type pilot relay in which a pressure corresponding to an input acting on a valve is used as an acting force for opening and closing a valve, a second pneumatic passage is provided from the intake port side of the pneumatic passage to the output port, and the second pneumatic passage is provided. A second through hole is formed in a second internal partition wall provided midway opposite the internal partition wall so as to be coaxial with the through hole, and a side edge of the second through hole is used as a valve seat. A non-bleed type pilot relay characterized in that a second valve body is provided on the valve shaft of the plunger valve in parallel with the valve body.