JPS6160315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a negative pressure control valve, and a control valve for supplying negative pressure to various negative pressure operating devices for automobiles.

BACKGROUND ART Various improvements are being made to control valves that control negative pressure for operating actuators such as exhaust purification devices of automobile engines and other so-called devices, with the aim of reducing the overall weight and cost of automobiles.

The present invention is in accordance with the above object, and utilizes a mechanism in which a snap acting disk and a signal negative pressure responsive diaphragm piston are interlocked via a spring to perform on/off control for opening and closing a valve. This controls the negative pressure input to the negative pressure operating device.

In the figure, the first body 1 on the right side has a port 2 for opening to the atmosphere and the port 3 for input, and the second body 4 on the left side has a port 5 for signal input. The input port 3 communicates via an orifice 6 with a negative pressure source 7, for example an intake manifold of an automobile engine, and on the other hand directly with a negative pressure actuator 8.

The inside of the housing H formed by the first body 1 and the second body 4 is divided into a signal chamber 10 and an atmospheric chamber 11 by a diaphragm piston 9. The periphery of the rolling diaphragm 12 is connected to the first body 1 and the second body.
It is sandwiched between the piston 13 and the body 4 to form a seal, and its inner periphery is sealed and engaged with an annular groove on the outer periphery of the piston 13. The piston 13 is a return spring 14
One end of the spring 14 is received, and the other end of the spring 14 is the retainer 1.
I'll take it in 5. The retainer 15 is movably supported by a projection 16 on the inner bottom surface of the second body 4 and received by an adjustment screw 17. 18 is a sealing material.

The right end of the piston 13 abuts against the holding member 19 to maintain a stationary position. The holding member 19 has a cylindrical shape and is firmly fitted to the protrusion 20 on the inner bottom surface of the first body, thereby forming one body with the first body 1. The protrusion 20 has a valve seat 21 at its inner end. The valve seat 21 cooperates with the valve 22 to form a valve mechanism, and communicates or blocks the port 3 and the chamber 11. The valve 22 retains a snap-acting disk 23 by a retaining ring 24. The compression coil spring 25 has its right end in the drawing received by the snap acting disk 23 and its left end received by the piston 13. The other compression coil spring 26 receives the periphery of the snap-acting disk 23 at its right end;
The left end is received by the stepped portion 27 of the holding member 19. Note that the other surface of the peripheral edge of the snap-acting disk 23 faces the annular edge 28 of the protrusion 20.

Next, the operation of the control valve described above will be explained.

In the illustrated state, since the valve 22 is seated on the valve seat 21, the negative pressure supplied from the negative pressure source 7 through the orifice 6 is supplied to the negative pressure actuating device 8. When the valve 22 is opened by a controlled operation as described later, air from the port 2 is supplied to the port 3 via the chamber 11.
The negative pressure that was being supplied to the negative pressure operating device 8 via the air is extinguished by this air and is no longer supplied to the negative pressure operating device 8. That is, the negative pressure input to the negative pressure actuation device 8 is subjected to so-called on/off control.

When negative pressure as a signal input is supplied from port 5, a pressure difference is generated between chamber 10 and chamber 11 which is open to the atmosphere. As a result, the diaphragm piston 9 moves to the left in the figure due to this differential pressure, allowing the spring 25 to expand and weakening its spring force. Although the snap-acting disk 23 is shown curved convexly to the right in the figure, stress is set so that it curves convexly to the left if it is released freely. When the spring force of the spring 25 weakens until the ratio of this stress to the opposing spring force of the compression spring 25 reaches a certain set value, the snap-acting disk 23 changes to a convex state to the left. As a result, the snap-acting disk 23 brings its peripheral edge into contact with the annular edge 28 of the protrusion 20, opening the valve 22 that was previously seated. Therefore, as described above, atmospheric pressure is supplied to the port 3 and the negative pressure input to the negative pressure operating device 8 is stopped. There is then a groove 29 in the annular edge 28 that allows atmospheric pressure to pass through.

In the above operation, even if the input signal to the port 5 is supplied with continuous changes, and therefore even if the spring 25 gradually weakens or strengthens the spring force, the snap-acting disk 23
Due to the relationship between the above-mentioned set stress and this spring force,
In position, it curves convexly to the left or right in the figure. In other words, the on/off control of valve 2 is performed before and after this value.
2 will be applied. During this operation, the outer spring 26 lightly abuts the periphery of the snap-acting disk 23 to position the snap-acting disk and assist in the above-mentioned operation.

As described above, the control valve of the present invention is capable of performing on/off control using a simple combination of the spring 25 and the snap acting disk 23 at two positions before and after a signal negative pressure input within a predetermined range.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of the control valve of the present invention. 2... port for atmospheric pressure, 3... input port for negative pressure source, 5... port for signal negative pressure input.

Claims (1)

[Claims] 1 A housing whose interior is divided into a chamber 10 to which negative pressure is supplied by a diaphragm piston and a chamber 11 open to the atmosphere, and a port for signal input provided in the housing and leading to the chamber 10 to which negative pressure is supplied. 5. An atmosphere opening port 2 provided in the housing and communicating with a chamber 11 that is open to the atmosphere, an input port 3 provided in the housing, a valve 22 that is normally seated on a valve seat 21 at the inner end of the input port, and One end has a diaphragm piston and the other end has a spring 25 seated on a valve 22, and the valve has a snap-acting disk for abutting its circumferential edge against an annular edge on the inner wall side of the housing. When the force of the spring is weakened by actuation, the snap-acting disk reverses and opens the valve, opening the chamber 11 to open the input port to the atmosphere.
A negative pressure control valve characterized by communicating with.