JPH0476024B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a diaphragm actuator suitably used in idle speed control devices and the like.

BACKGROUND ART This type of diaphragm actuator includes a negative pressure chamber 2 into which a negative pressure signal from a negative pressure source 26 is introduced, as shown in FIG.
7, a spring member 30 interposed between the cover 29 for moving the diaphragm 28 in response to the negative pressure signal, and a throttle valve 31 attached to the diaphragm surface on the opposite side from the negative pressure chamber side. In the diaphragm actuator equipped with a connecting rod 32, a plurality of nipples 34a, 34b, 34 are installed through the cover, the tips of which constitute valve seats 33a, 33b, 33c, and which introduce negative pressure from a negative pressure source.
c, and a plurality of valves 36a, 36b, 3 installed via spring members 35a, 35b, 35c at positions facing the valve seats on the diaphragm.
6c, another negative pressure path 37 communicating the negative pressure chamber and the negative pressure source, and a leak hole 38 for the negative pressure chamber are provided, and the negative pressure path connected to the nipple and the other negative pressure source are provided. An actuator in which the position of the diaphragm is changed in a plurality of stages using means for selectively introducing negative pressure from a pressure path is disclosed in Japanese Patent Publication No. 57-40949.

Problems to be Solved by the Invention However, in the conventional actuator,
Negative pressure is supplied to multiple signal supply lines for idle up, so special care must be taken with the piping, and rubber tubes must be airtightly connected to prevent air from entering. Furthermore, since a plurality of valves are provided on the diaphragm side and a plurality of corresponding nipples are attached to the cover, there is a problem in that both of them must be attached in precise positions.

Means for Solving the Problems The present invention solves the above problems by providing a plurality of atmospheric pressure introduction valves for idle up in the negative pressure chamber so as to face the diaphragm. Specifically, in an actuator as shown in FIG. 1, in which a throttle valve opening adjustment rod 2 is attached to a diaphragm 1, a plurality of atmospheric pressure introduction valves 5a, 5b, . . . are installed in a negative pressure chamber 3. A diaphragm actuator is provided, in which one end 6a, 6b, . Eta, is.

Function When attempting to prevent a decrease in the idle rotation speed during various electrical loads such as when using an air conditioner or power steering, any one of the atmospheric pressure introduction valves 5a, 5b, . . . is communicated with the atmosphere. At this time, of course, all the ports of the other atmospheric pressure introduction valves are in a sealed state. Therefore, for example, when the atmospheric pressure introduction valve 5a communicates with the atmosphere, the atmosphere from the port 10a enters the negative pressure chamber and reduces the degree of negative pressure in the chamber, thereby lowering the diaphragm 1 and slightly lowering the throttle valve 9. Open it to perform idle up. Since the atmospheric pressure introduction valve 5a is opened until one end 6a separates from the diaphragm, the purpose is achieved by setting the distance 7a commensurate with the amount of idle up.

The same applies when the atmospheric pressure introduction valve 5b communicates with the atmosphere, and in this case, the port 10 of the atmospheric pressure introduction valve 5a
Since the valve a is in a sealed state, the atmospheric pressure introducing valve 5b operates independently of the atmospheric pressure introducing valve 5a.

Embodiment An embodiment of the present invention will be described below with reference to FIG.

The actuator consists of an upper casing 11 and a lower casing 12, and a diaphragm 1 is sandwiched between the two casings.

The diaphragm 1 has plates 13 on its upper and lower surfaces.
a and 13b, and a rod 2 is attached to the center. This rod is the intake manifold 14
This restricts the degree to which the throttle valve 9 is closed. Further, a spring 15 for pressing the diaphragm is provided between the upper surface plate 13a and the upper casing 11.

The upper casing 11 includes an atmospheric pressure introduction valve 5a,
5b and a valve 4 for generating a dart pot effect are attached, and the ports 10a and 10b of each atmospheric pressure introduction valve 5a and 5b are connected to an electromagnetic switching valve 16a and 16b that can be switched to open to the atmosphere and closed (blind), respectively.
The ports are connected to orifices 17a and 17b, respectively. Further, the negative pressure port 8 of the valve 4 for generating the dart pot effect is connected to the intake manifold 14.

Each of the atmospheric pressure introduction valves 5a, 5b has one end 6a, 6.
b is provided with valve operating members 18a and 18b located at distances 7a and 7b from the diaphragm surface, and the valve operating members have a plurality of grooves 19 on the outer periphery of the upper flange portion.
a, 19b are formed, and when the valve is opened and atmospheric air is sent, it becomes an atmospheric passage from the ports 10a, 10b to the negative pressure chamber. Then, the valve operating member 1
8a and 18b are springs 20a and 20, respectively.
b is biased in the closing direction.

Valve seat 2 of the valve 4 for generating the dart pot effect
1 is provided with a plurality of holes 22 and slits 23, and the holes are covered by check valves 24. Further, perforated plates 25 are provided above and below the valve seat 21 to prevent rapid transmission of negative pressure.

When this actuator is used in a car engine idle speed control device, during normal driving, the negative pressure in the intake manifold 14 is small, so the negative pressure in the negative pressure chamber 3 is proportionally small, and the diaphragm 1 absorbs the load of the spring 15. Accordingly, the rod 2 descends to maintain the throttle valve 9 in an open state.

At normal idle, intake manifold 1
Since the negative pressure in the negative pressure chamber 4 is large, the negative pressure in the negative pressure chamber 3 is also large in proportion to it, and the diaphragm 1 is moved by the spring 15.
The rod 2 rises to overcome the load of the throttle valve 9, and the rod 2 rises accordingly to maintain the throttle valve 9 in a closed state. Since the large negative pressure generated at this time is introduced into the negative pressure chamber through the hole 22 and the slit 23, the diaphragm 1 rises slowly, and the stroke speed of the rod 2, that is, the closing speed of the throttle valve, becomes gradual. A darth pot effect occurs. Further, since the electromagnetic switching valves 16a and 16b are each sealed, the atmosphere will not enter the negative pressure chamber even if the atmospheric pressure introduction valves 5a and 5b are open.

If a slight increase in idle is desired, the distance between one end of the atmospheric pressure inlet valve and the diaphragm is long7.
a Switch the electromagnetic switching valve 16a on the atmospheric pressure introduction valve 5a side to open it to the atmosphere. As a result, the atmosphere enters the negative pressure chamber through the open atmospheric pressure introduction valve 5a, lowers the degree of negative pressure, and the diaphragm descends. Along with this, the rod 2 also descends, causing the throttle valve 9 to shift to a slightly open state. . Due to the lowering of the diaphragm, when the one end 6a separates from the diaphragm, the atmospheric pressure introduction valve 5a is closed, and the entry of the atmosphere is stopped and the lowering of the diaphragm is stopped, so that the throttle valve is not opened any further. At this time, the other atmospheric pressure introduction valve 5b is still in an open state due to the diaphragm, but since the electromagnetic switching valve 16b is not opened to the atmosphere, it is unrelated to the movement of the diaphragm.

If a further increase in idle is desired, the electromagnetic switching valve 16a on the atmospheric pressure introduction valve 5a side is closed, and the electromagnetic switching valve 16b on the atmospheric pressure introduction valve 5b side is switched to open to the atmosphere. As a result, the atmosphere enters the negative pressure chamber through the open atmospheric pressure introduction valve 5b, lowers the degree of negative pressure, and the diaphragm descends. Along with this, the rod 2 also descends, opening the throttle valve 9 to a somewhat larger degree. let Due to the lowering of this diaphragm,
When the one end 6b separates from the diaphragm, the atmospheric pressure introduction valve 5b is closed, and the entry of atmospheric air stops and the diaphragm stops descending, so the throttle valve is no longer opened.

In this manner, by opening either of the electromagnetic switching valves 16a, 16b to the atmosphere, the degree of idle increase can be adjusted in multiple stages.

Effects of the Invention Since the present invention supplies atmospheric air to a plurality of signal supply paths for idle up, no particular care is required for the piping, and the pipes themselves can be simple. In addition, since multiple atmospheric pressure introduction valves are installed facing the diaphragm, the atmospheric pressure introduction valves can be installed anywhere within the plane of the diaphragm, so special consideration must be given to the installation position of the valves. It has the advantage of not being

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the actuator according to the present invention, and FIG. 2 is an explanatory view of a conventional example. DESCRIPTION OF SYMBOLS 1... Diaphragm, 2... Throttle valve opening adjustment rod, 3... Negative pressure chamber, 5a, 5b... Atmospheric pressure introduction valve, 6a, 6b... One end of atmospheric pressure introduction valve, 7
a, 7b...Distance between one end of the atmospheric pressure introduction valve and the diaphragm.

Claims (1)

[Claims] 1. In an actuator with a throttle valve opening adjustment rod attached to the diaphragm, a plurality of atmospheric pressure introduction valves are provided in the negative pressure chamber, and one end of each atmospheric pressure introduction valve facing the diaphragm is placed at a different distance from the diaphragm. A diaphragm actuator, characterized in that the atmospheric pressure introduction valve is opened by a diaphragm that faces each other.