JPH0326326Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a diaphragm actuator used in automobiles and the like.

[Conventional technology]

Conventionally, as a type of diaphragm actuator, as shown in FIG. 3, an inner chamber of a case 1 consisting of a housing 3 and a diaphragm cap 2 mounted on the housing 3 is formed so that an outer peripheral edge 4b thereof is connected to the diaphragm cap 2. The diaphragm cap 2 side is connected to the diaphragm cap 2 by a combo-type diaphragm 4 made of a flexible material, which is airtightly clamped between the housings 3 and whose central portion 4c is connected to the end of a rod 5 inserted into the shaft hole of the housing 3. The diaphragm chamber 6 is separated into a second chamber 7 on the housing 3 side, and the diaphragm 4 is urged toward the second chamber 7 side by a coil spring 8 elastically loaded in the diaphragm chamber 6. Some structures are known. This actuator is driven by obtaining negative pressure from the inlet manifold of the engine (not shown), and when the negative pressure is applied via the boost nipple 9 and the pressure in the diaphragm chamber 6 decreases,
The diaphragm 4 receives the differential pressure from the second chamber 7 side and operates in a direction to contract the volume of the diaphragm chamber 6 while resisting the elasticity of the coil spring 8.

[Problem that the invention attempts to solve]

Incidentally, the inlet manifold of an engine equipped with a charger is sometimes under positive pressure, and when this positive pressure is applied to the diaphragm chamber 6 of the actuator, the diaphragm 4
The curved portion 4a is reversed to the second chamber 7 side where the pressure is relatively low. In this case, especially the curved portion 4a
Since excessive stress (due to bending) occurs at the inner and outer circumferences 4d and 4e due to inversion, there has been a problem in that durability is significantly impaired.

Note that if a dish-shaped diaphragm is used in the actuator that is subjected to both positive and negative pressures as described above, reversal will not occur when there is a reverse pressure (in the above case, positive pressure), but the dish-shaped diaphragm will widen the stroke range. Not only cannot the setting be made, but also the resistance becomes large at high strokes, causing scuffing and the like, making it easy to break. In addition, in the case of an actuator that operates with both positive and negative pressures, two diaphragms may be used in combination in opposite directions, but as in the conventional example above, the structure operates only during negative pressure (or positive pressure). If two diaphragms are used in the actuator, reversal at the time of reverse pressure can be prevented, but the cost will be high and the resistance during operation will also be large.

[Means for solving problems]

In view of the above-mentioned problems, the present invention was devised to improve the durability of the diaphragm by providing a valve mechanism that eliminates back pressure to the diaphragm. The diaphragm chamber and the second chamber are separated by a combo-type diaphragm having a curved portion, and the diaphragm is directed toward the side where the pressure is relatively high due to the application of operating pressure to the diaphragm chamber. In the elastically biased diaphragm actuator, a valve hole is provided in the case to allow the diaphragm chamber to communicate with the atmosphere, and the diaphragm chamber has a pressure opposite to the operating pressure in the valve hole. The structure is such that a valve body is attached so as to be able to freely approach and separate, and which performs an opening operation when necessary.

[Effect]

According to the above configuration of the present invention, when a pressure opposite to the operating pressure acts in the diaphragm chamber, the valve body immediately opens and the diaphragm chamber is opened to the atmosphere through the valve hole, so that the diaphragm is reversed. Never. Further, when operating pressure is applied to the diaphragm chamber, the valve body immediately seals the valve hole, so that the diaphragm can perform normal operation.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Incidentally, the same reference numerals are used for the parts having the same configuration as those of the conventional example shown in FIGS. 3 and 4 described above, and only the different parts will be explained.

That is, the present embodiment shown in FIG. 1 is an application of the configuration of the present invention to a negative pressure operated diaphragm actuator. A valve hole 1 that allows the diaphragm chamber 6 to communicate with the atmosphere side (outside)
A breather housing 12 having a substantially flat dish shape and having ventilation holes 13 and 14 formed in the side and top portions, respectively, is provided on the top surface of the diaphragm cap 2 so as to surround the valve hole 11. A valve mechanism 10 is provided in which a thin plate-shaped valve body 16 made of a rubber material is freely inserted into a valve chamber 15 formed by a diaphragm cap 2 and a breather housing 12, which are welded together.

In the above configuration, the valve body 16 normally comes into contact with the valve seat 17 around the valve hole 11 due to gravity, and
When negative pressure from an inlet manifold (not shown) is applied to the diaphragm chamber 6 via the boost nipple 9, the valve element 16 closes to the valve seat 17 due to the pressure difference with the atmosphere side. The diaphragm 4 is operated by completely sealing the valve hole 11. In addition, when a positive pressure that is the opposite pressure to the negative pressure (operating pressure) is applied, the positive pressure causes the valve body 16 to immediately move from the valve seat 17 to the breather housing 12. The valve is opened freely toward the top side, and the diaphragm chamber 6 is connected to the valve hole 11 and the valve chamber 1.
5 and the vent hole 13, the pressure inside the diaphragm chamber 6 does not increase, and therefore the curved portion 4a of the combo-type diaphragm 4 does not invert toward the second chamber 7 side.

[Effect of idea]

As explained above, the present invention provides a diaphragm actuator that uses a combo-type diaphragm having a curved portion, and is provided with a valve mechanism that eliminates the counter pressure against the operating pressure when it is applied inside the diaphragm chamber. This valve mechanism, which is relatively inexpensive, has the effect of preventing the curved portion of the diaphragm from inverting and improving durability.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of the main part when positive pressure is applied, Fig. 3 is a longitudinal sectional view showing an example of the conventional structure, and Fig. 4 is a longitudinal sectional view showing an example of the conventional structure. It is a longitudinal cross-sectional view when positive pressure is similarly applied. 1... Case, 4... Combo type diaphragm,
4a...Bending portion, 6...Diaphragm chamber, 7...
2nd chamber, 8... Coil spring, 10... Valve mechanism, 11... Valve hole, 12... Breather housing, 13, 14... Vent hole, 15... Valve chamber, 16
... Valve body, 17... Valve seat.

Claims (1)

[Scope of utility model registration request] The inner chamber of the case is separated into a diaphragm chamber and a second chamber by a combo-type diaphragm extended within the case and having a curved portion, and the diaphragm is separated into a second chamber by applying operating pressure to the diaphragm chamber. In the diaphragm actuator, the case is provided with a valve hole that communicates the diaphragm chamber with the atmosphere, and the diaphragm chamber is connected to the valve hole. 1. A diaphragm actuator, characterized in that a diaphragm actuator is provided with a valve element that can be freely approached and separated, and which performs an opening operation when the pressure becomes opposite to the operating pressure.