JPS623322B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuator with a diaphragm actuated by fluid pressure.

A conventional actuator equipped with a diaphragm divides the inside of the case into two chambers by the diaphragm, one of which is a pressure chamber into which positive pressure or negative pressure is introduced;
The other chamber is an atmospheric pressure chamber open to the atmosphere.
In this type of actuator, the actuating rod connected to the diaphragm is usually loosely inserted into the opening that communicates the atmospheric pressure chamber with the atmosphere, and the actuator is operated in this way. In an actuator in which a rod is loosely inserted into an opening, in addition to the flexibility of the diaphragm, reciprocating motion and rocking are applied to the actuating rod, such as when driving a lever as an actuated member in reciprocating rotation. It has the advantage that it does not interfere with its operation. On the other hand, however, since the gap between the inner circumferential edge of the opening and the actuating rod becomes larger, it becomes easier for dust to enter the atmospheric pressure chamber through the gap, and there is a risk that the dust may damage the diaphragm.

In order to improve this problem, it is possible to install a boot on the outside of the case between the opening of the case and the actuating rod, but if the boot is installed on the outside of the case, this actuator is When used as an actuator for an EGR valve installed in a car or as an actuator for a wastegate valve used in a turbocharger, the boot had the disadvantage of being easily damaged by pebbles, mud, etc.

In view of these circumstances, the present invention provides an actuator that improves the above-mentioned drawbacks by housing the boot inside the case.

The present invention will be described below with reference to the illustrated embodiments.
In FIG. 1, 1 is a case formed by abutting an upper case 2 and a lower case 3, and 4 is a case whose outer periphery is held between the upper case 2 and lower case 3, and the inside of the case 1 is pressurized. A diaphragm divides the chamber into a chamber 5 and an atmospheric pressure chamber 6, and in this embodiment, the pressure chamber 5 is communicated with a positive pressure source (not shown) via a pressure fluid introduction hole 7.

At the center of the diaphragm 4, a pair of diaphragm plates 9 and 1 are provided on both upper and lower surfaces.
0 and a washer 11, and the other end of the actuating rod 12 is loosely fitted through an opening 8 formed in the lower case 3 and connected to, for example, an opening/closing lever of a waste gate valve. are doing. A compression spring is loaded between the lower case 3 and the lower diaphragm plate 10 to urge the actuating rod 12 upward;
Normally, a stopper portion 14 formed on the outer periphery of the upper diaphragm plate 9 is held in a position where it comes into contact with the inner surface of the upper case 2. Note that positive pressure is also introduced into the pressure chamber 5 at the outer circumference of the lower diaphragm plate 10, and the actuating rod 12 is moved by the spring 13.
A stopper portion 15 is formed which comes into contact with the inner surface of the lower case 3 and prevents the actuating rod 12 from further lowering when the actuating rod 12 is actuated against the force.

In this embodiment, however, the boot 20 is inserted into the atmospheric pressure chamber 6, one end of which is connected to a collar 21 attached to the actuation rod 12, and the other end connected to a bracket 22 and a plate 24 attached thereto with screws 23. By sandwiching the opening 8 with the opening 8, the opening 8 is completely sealed. Communication between the atmospheric pressure chamber 6 and the atmosphere is provided by a hole 25 bored in the lower case 3.
As shown in FIG. 2, the lower case 3 is formed through a labyrinth 28 consisting of an annular passage 26 and a radial passage 27 integrally formed therein.

With the above configuration, if pressure fluid is introduced into the pressure chamber 5, the actuating rod 12 can be lowered against the spring 13, and if the pressure fluid is discharged from the pressure chamber 5, the spring 13 will be elastic. The actuating rod 12 can be raised by the repulsive force. At this time, even if the actuating rod 12 swings by reciprocally rotating the opening/closing lever of the gate valve, the diaphragm 4
And since the boot 20 is deformed, the actuation rod 12
operation is not inhibited.

Since the boots 20 are housed in the case 1, the boots 20 are protected from pebbles, mud, etc. by the case 1.
damage can be effectively prevented. Further, the boot 20 completely seals the large opening 8 for allowing the swinging of the actuating rod 8, and the atmospheric pressure chamber 6 communicates with the atmosphere through a small diameter hole 25 and a labyrinth 28 that prevent dust from entering. Therefore, the intrusion of dust can be effectively prevented. Note that the hole 25 for communicating the atmospheric pressure chamber 6 with the atmosphere may be provided in the boot 20.

Next, FIG. 3 shows another embodiment of the present invention, in which one end of the boot 20 is directly fitted into a step 30 formed on the actuating rod 12 by its own elasticity. The other end is also fitted into the inner peripheral edge of the opening 8. The atmospheric pressure chamber 6 is communicated with the atmosphere by forming a through hole 32 in a recess 31 formed by expanding a part of the bottom surface of the lower case 3 into the atmospheric pressure chamber 6. The other configurations are not substantially different from those of the above embodiment, and the same parts are denoted by the same reference numerals. It is clear that even in this embodiment having such a configuration, the same effects as in the above embodiment can be obtained.

In addition, in the embodiment described above, the boots 20
Although one end of the diaphragm 4 is connected to the actuating rod 12 via the collar 21 or directly, it is of course possible to connect the diaphragm 4 to the diaphragm 4 via the diaphragm plate 10.

As described above, since the boots are housed in the case according to the present invention, the boots can be protected from pebbles, mud, etc. by the case.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view taken along the - line in FIG. 1, and FIG. 3 is a sectional view showing another embodiment of the present invention. 1... Case, 4... Diaphragm, 5... Pressure chamber,
6... Atmospheric pressure chamber, 8... Opening, 12... Actuation rod, 2
0...Boots.

Claims (1)

[Claims] 1. In an actuator comprising a diaphragm that divides the inside of the case into a pressure chamber and an atmospheric pressure chamber, and an actuation rod that loosely fits through an opening formed in the case and is connected to the diaphragm, one end of the boot is connected to the opening part. An actuator characterized in that the other end of the boot is connected to an actuating rod or diaphragm inside the case.