JPH07269512A - Diaphragm type actuator - Google Patents

Abstract

PURPOSE:To prevent a diaphragm from being damaged by cracks and the like by preventing the inner wall of a piston from interfering with the diaphragm. CONSTITUTION:A slip-in-position preventive circular projected section 18C locking one end of a coil for a coil spring 7, which is roughly identical in height to the diameter of a coil wire for the coil spring 7, is integrally formed at a boarder section between the abutting section 18A of a retainer 18 and its fit-in section 18B. By this constitution, even when an actuator is severely vibrated by the vibration of an engine and a vehicle, the coil end of the coil spring 7 is firmly locked at the circular projected section 18C, the coil spring is thereby restrained from being vibrated in such a way as to be reciprocally moved in the radial direction of the retainer 18, and the inner wall of a piston 3 can be prevented from interfering with a diaphragm 2, so that the diaphragm 2 can thereby be prevented from being damaged by cracks and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm type actuator for controlling a wastegate valve of a turbocharger of an engine, and more particularly to a technique for suppressing a behavior of a coil spring provided in an actuator body.

[0002]

2. Description of the Related Art Conventionally, a diaphragm type actuator has been known as an actuator for controlling a wastegate valve of a turbocharger of an engine and an actuator for driving a nozzle vane of a variable displacement turbocharger (Japanese Utility Model Publication No. 5-89842 and Japanese Utility Model Publication No. Hei 5-98842). 3-9252
No. 8, etc.).

An example of this is shown in FIG. 3, in which the inside of the actuator body 1 is divided into a control pressure chamber A and an atmospheric pressure chamber B by a diaphragm 2. In the piston 3 arranged inside the recess of the diaphragm 2, a through hole 4 formed in the wall of the actuator body 1 and a resin bush 5 arranged around the through hole 4 on the inner surface of the actuator body 1 wall. An operating rod 6 which is slidably supported through is connected to the.

A coil spring 7 is provided between the piston 3 and the inner surface of the wall of the actuator body 1 to elastically bias the diaphragm 2 to a position which is normally deformed to the control pressure chamber A side (left half of the figure). Is installed. Then, on the inner surface of the wall of the actuator body 1 on the atmospheric pressure chamber B side, a contact portion 8 with which one coil end of the coil spring 7 abuts.
A retainer 8 including A and a fitting portion fitted to the bush 5 is provided.

When pressure is applied to the control pressure chamber A,
The diaphragm 2 is at a position where it is deformed to the atmospheric pressure chamber B side against the elastic biasing force of the coil spring 7 (the right half state in the figure), the piston 3 operates downward in the figure, and the operating rod 6 similarly. Operate.

[0006]

However, in such a conventional diaphragm type actuator,
There are the following problems. That is, for example, an actuator for controlling a wastegate valve vibrates violently due to vibration of an engine or a vehicle, and the vibration causes the coil spring 7 and the piston 3 in the actuator to resonate with each other. The inner 3 walls and the diaphragm 2 may interfere with each other, and the diaphragm 2 may be damaged such as cracks.

In this case, as shown in the figure, the coil spring 7 vibrates such that the contact portion with the retainer 8 reciprocates in the radial direction of the retainer 8 from the contact portion with the diaphragm 2. Occur. Therefore, in view of the conventional problems as described above, the present invention prevents the piston inner wall and the diaphragm from interfering by suppressing the behavior of the coil spring provided in the actuator body, and the diaphragm is cracked or the like. The purpose is to prevent the damage of.

[0008]

Therefore, according to the first aspect of the invention, the inside of the actuator body is divided into a control pressure chamber and an atmospheric pressure chamber by a diaphragm, and the piston arranged inside the diaphragm is formed. An inner surface of the piston body and an inner surface of the actuator body wall that are interlocked with a through hole formed in the actuator body wall and an operating rod that is slidably supported by a bush provided around the through hole in the inner surface of the actuator body wall. And a coil spring that elastically biases the diaphragm to a position that is normally deformed toward the one chamber side, and one coil end of the coil spring on the inner surface of the actuator body wall on the other chamber side. In a diaphragm type actuator provided with a retainer consisting of an abutting portion where the At the boundary between the abutting portion and the fitting portion of the retainer, the height of the coil wire is approximately the same as the coil wire diameter of the coil spring, and the positional displacement is such that one coil end of the coil spring is locked. An annular convex portion for prevention is provided.

[0009]

In the invention of claim 1, even when the actuator violently vibrates due to the vibration of the engine or the vehicle, the contact portion of the coil spring with the retainer is locked by the annular convex portion. Vibration that reciprocates in the radial direction of the retainer does not occur.

Therefore, it is possible to prevent the inner wall of the piston and the diaphragm from interfering with each other, and to prevent the diaphragm from being damaged such as cracks. In this case, since the annular convex portion is formed so as to have substantially the same height as the coil wire diameter of the coil spring, the coil end of the coil spring does not get over the annular convex portion, and a plurality of coil ends are not formed. The coil wire does not interfere with the annular projection, and the coil spring is not worn.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. In FIG. 1, inside a main body 1 of an actuator for controlling a waste gate valve of a turbocharger of an engine, a control pressure chamber A and an atmospheric pressure chamber B are provided by a diaphragm 2.
The piston 3 is divided into two parts, and is arranged inside the recess of the diaphragm 2, the operating rod 6 connected to the piston 3, the coil spring 7, and the retainer 18 are provided. Is.

The configuration different from the conventional one is as follows. That is, the dish-shaped portion 1 in which the retainer 18 is provided with the contact portion 18A with which one coil end of the coil spring 7 contacts
8a and the central portion of the recess of the dish-shaped portion 18a are bulged to form the lower surface of the dish-shaped portion 18a.
And a fitting portion 18B that is fitted to the.

At the boundary between the abutting portion 18A and the fitting portion 18B of the retainer 18, the coil spring 7 has a height H which is substantially the same as the coil wire diameter L of the coil spring 7. An annular protrusion 18C for locking the position that locks one of the coil ends is integrally formed (see FIG. 2). The annular convex portion 18C is formed on the upper surface of the boundary portion by protruding the annular boundary portion between the contact portion 18A and the fitting portion 18B of the retainer 18.

For example, the coil wire diameter L of the coil spring 7 is 3 mm, and the height H of the annular convex portion 18C is 3.1 mm. According to such a configuration, for example, even when the actuator vibrates violently due to the vibration of the engine or the vehicle, the coil end of the coil spring 7 is locked to the annular convex portion 18C as shown in FIG. Therefore, vibration that reciprocates in the radial direction of the retainer 18 is not generated.

Therefore, the inner wall of the piston 3 and the diaphragm 2
The diaphragm 2 can be prevented from interfering with each other.
It is possible to prevent the occurrence of damage such as cracks. In this case, in particular, the annular convex portion 18C is the coil spring 7
Since it is formed to have substantially the same height as the coil wire diameter of, there are the following advantages. That is, the annular convex portion 18C
When the height is smaller than the coil wire diameter of the coil spring 7, the coil end of the coil spring 7 gets over the annular convex portion 18C, and the vibration cannot be suppressed. On the contrary, when the annular convex portion 18C has a height significantly higher than the coil wire diameter of the coil spring 7, the plurality of coil wires at the coil ends interfere with the annular convex portion 18C and the coil spring 7 Causes wear.

In this respect, if the annular protrusion 18C is formed to have a height substantially equal to the coil wire diameter of the coil spring 7, the coil end of the coil spring 7 has the annular protrusion 1
8C is not overcome, and the plurality of coil wires at the coil ends do not interfere with the annular convex portion 18C, so that the coil spring 7 is not worn. In addition, retainer 1
8, the diameter of the fitting portion 18B of
It is conceivable that B itself holds the coil end of the coil spring 7, but in this case, as described above,
A plurality of coil wires at the coil ends interfere with the fitting portion 18B to cause wear of the coil spring 7, and the bush 5 itself needs to be large.

In the above embodiment, the example in which the present invention is applied to the waste gate valve control actuator of the engine turbocharger has been described, but the present invention is also applied to the nozzle vane drive actuator of the variable capacity turbocharger. It is possible and applicable not only to the actuator for the turbocharger but also to other actuators for actuation.

[0018]

As described above, according to the first aspect of the present invention, the retainer is provided which includes the abutting portion with which the coil end of the coil spring abuts and the engaging portion with which the bush is fitted. In the diaphragm type actuator, at the boundary between the abutting portion and the fitting portion of the retainer, an annular convex portion for preventing positional deviation that locks one coil end of the coil spring is provided,
The behavior of the coil spring can be suppressed, interference between the inner wall of the piston and the diaphragm can be prevented, and damage to the diaphragm such as cracks can be prevented. Since it is formed so as to have a height approximately equal to the coil wire diameter of, the coil end of the coil spring does not get over the annular convex portion, and a plurality of coil wires at the coil end interfere with the annular convex portion. As a result, there is an advantage that the coil spring is not worn and there is no need to change the shapes of other components.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged view of the annular convex portion of FIG.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

 1 Actuator Main Body 2 Diaphragm 3 Piston 6 Operating Rod 7 Coil Spring 18 Retainer 18A Abutting Part 18B Fitting Part 18C Annular Convex Part A Control Pressure Chamber B Atmospheric Pressure Chamber

Claims (1)

[Claims] 1. A control pressure chamber and an atmospheric pressure chamber are partitioned from each other by a diaphragm in the actuator body, and a piston disposed inside the diaphragm has a through hole formed in the actuator body wall and the actuator body. An operating rod slidably supported by a bush provided around the through hole on the inner surface of the wall is interlocked, and the diaphragm is normally provided between the inner surface of the piston and the inner surface of the actuator body wall on the one chamber side. A coil spring that elastically biases the deformed position of the coil spring is interposed, and the contact portion where one coil end of the coil spring abuts the inner surface of the actuator body wall on the other chamber side and the fitting that is fitted to the bush. In a diaphragm type actuator provided with a retainer composed of a mating portion, the contact portion and the fitting portion of the retainer A diaphragm type which is provided at the boundary with an annular protrusion having a height substantially equal to the coil wire diameter of the coil spring and for preventing one of the coil ends of the coil spring from being displaced. Actuator.