JPS6155483A - Pilot type solenoid operated valve - Google Patents

Abstract

PURPOSE:To perform the norma action by an internal piloe even when a pneumatic pressure source is not connected with a main port, by providing a check valve generating a free flow toward a pilot flow path from at least two or more ports. CONSTITUTION:A pilot type solenoid operated valve of five-port two-position single solenoid provides in a subplate 11 a main port P, exhaust ports R1, R2 and output ports A, B. Here the valve provides five check valves 23, generating a free flow toward a pilot flow path 22 from said each port, between a valve main body 12 and a pilot plate 13. Now if the check valve 23, communicating with the maximum high pressur port, opens to apply the high pressure to the pilot flow path 22, the pilot pressure acts in a pilot chamber 19a actuating a small piston 19 to move a spool 17 leftward. While a solenoid part 17, if it is switched, connectes the pilot flow path 22 with a pilot chamber 18a, actuating a large piston 18 to move the spool 17 rightward.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pilot type solenoid valve in which a spool is operated by an internal pilot, and is used, for example, when switching and supplying high or low air pressure to a pneumatic cylinder.

Conventionally, pilot-type solenoid valves have been frequently used compared to direct-acting types because the solenoid is smaller and there are almost no burnout accidents. Its structure is such that a pilot flow path for operating the spool is led from the main bow 1- (P port), and an air pressure source is usually connected to the main bow 1-. Therefore, the spool will not operate unless an air pressure source is connected to the main port. However, as shown in FIG. 4, for example, in order to supply air with different pressures to each chamber of the pneumatic cylinder 1, each exhaust bow 1-(1'?1°R2 port) of the 1.5-port valve 2 must be High pressure or low pressure air pressure sources 3 and 4 will be connected, and the main port will be used for exhaust. In this case, since it is impossible to use a conventional dual pilot solenoid valve, an external pilot 5 is used as shown in the figure.
The circuit must be connected and additional work and piping work must be carried out for that purpose.

Alternatively, special processing must be applied to change the internal pilot flow path.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a pilot type solenoid valve that can be operated normally by an internal pilot even when an air pressure source is not connected to the main port.

In order to achieve the above-mentioned object, the present invention provides at least two
A check valve is provided that allows free flow from one or more ports toward the pilot flow path.

The present invention will be described below based on embodiments and with reference to the drawings.

Figure 1 shows a complete electromagnetic piece with a 5-bow 1-2 position single solenoid, including the main port P, exhaust bow 1-R1, R2, output ports A, B, and the holes communicating with these. a sub-plate 11 having a valve body 1;
2, pilot pre=1-13, and solenoid part 14
, a terminal box 15 , and a connector 16 . A spool 17 and a large piston [8] and a small piston 19 at each end of the spool 12 are fitted into the valve body 12 so as to be able to slide left and right. 18a, 19a and communication hole 1
8b and 19b are provided. Between the valve body 2 and the spool 17, there are four sealing materials 20 for slidingly contacting the land portion of the spool 17 and sealing between each port.
... and spacers 21 for holding these sealing materials 20 in predetermined positions.

Referring also to Fig. 2, the valve body 12 and the piezo cylinder 1~
Each port P is connected to the plate 13.

Five check valves 23 . . . are provided that allow free flow from R1, R2, A, and B toward the pilot flow path 22. Each check valve 23 is arranged in a two-stage hole 25 provided in the valve body 12 and having a valve seat 24 so that the valve body 26 is pressed against the valve seat 24 by a spring 27. , a concave groove 28 that communicates with all five holes 25 on three sides, and the above-mentioned spring 27 at the bottom of this concave groove.
The spring receiving portion 29 into which the spring is fitted and pressed, and the concave groove 28
A hole 30 is provided through which the air flow path 22 and the air flow path 22 communicate with each other. The communication hole 18c allows communication between the communication hole 18b and the communication hole 18d. The pilot channel 22 communicates with the communication hole 19b and the pilot channel 22b through a communication groove 19d provided in the cover plate 13a and a communication hole 19C, respectively.

The solenoid part 14 normally connects the communication hole 18d to the atmosphere so as to open it to the atmosphere, but by applying current and energizing the solenoid, the communication hole 18d can be switched to be connected to the pilot flow path 22a. It is something.

A circuit diagram of a pyro-node type solenoid valve configured in two series is shown in Figure 3. To explain the operation of this pyro-node type solenoid valve based on Figures 1 to 3, there is a check that the circuit with the highest pressure among the circuits connected to each port from the outside is connected to the port connected to it. Valve 23 opens and high pressure is applied to pyro throat channel 22. This opens the communication hole 19d.

After 19c and 19b, Pyro/Nippon/Soviet 1-room 19a was installed.
Throat pressure acts on the spool 17 via the small piston 19.
moves to the left in FIG. 1, resulting in the circuit state shown in FIG. When the solenoid in the solenoid part 14 is excited and switched, the pilot flow path 22 is connected to the pilot chamber 18a through the communication holes 18b and 18c, and pilot pressure acts on the large piston 18 to overcome the reaction force of the small piston 19. Then, the spool 17 is moved to the right in FIG. 1 to switch the circuit.

In this way, according to the pyro-node type solenoid valve of this embodiment, no matter which bow 1- is connected to the air pressure source, it will operate normally and switch, so that the high pressure and low pressure Exhaust the two types of air pressure sources respectively) R1
, R2, it can be used without any problem, and output capo-1-A.

It can be used in the same way even when air pressure is supplied from B.

In the above embodiment, check valve 2 is provided for every port.
However, for example, the check valves 23 may be provided only for the three bows 1-P, R1, and R2, and the others may be shut off. The present invention can be used for all types of pilot operated solenoid valves, including spring return type, double solenoid type, 3-port or double-port type, 3-position type, and among them, closed center and Nigeshiest center set type. can.

As described above, according to the present invention, normal operation is performed by the internal pilot even when no air pressure source is connected to the main port, so it can be used in any fluid pressure circuit without connecting an external pilot or performing additional work. becomes possible.

[Brief explanation of drawings]

Fig. 1 is a partially sectional front view showing an embodiment of the present invention, Fig. 2 is an enlarged view of the main parts of Fig. 1, Fig. 3 is a circuit diagram of the pilot type solenoid valve shown in Fig. 1, and Fig. 4 is a circuit diagram showing an example of use using a conventional pilot type solenoid valve. P, l? 1. R2, A, B...port, 22...PI-NISSO 1-flow path, 23...check valve.

Claims (1)

[Claims] In a pilot-operated solenoid valve in which a pilot flow path is switched by actuation of a solenoid and a spool is operated to switch the flow path between each port, a free flow is generated from at least two or more ports toward the pilot flow path. A pilot operated solenoid valve equipped with a check valve.