JPH0419212Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is an actuator using a diaphragm that controls a controlled part of, for example, a throttle valve of an engine in response to negative pressure from a negative pressure source such as an intake passage. Regarding.

(Prior Art) As a conventional actuator of this type, the one shown in FIG. 4 has been proposed by the present applicant (Utility Application No. 59-23890). That is, the housing 100
A diaphragm 101 is attached to the negative pressure chamber 10.
2 is formed, and by introducing negative pressure into the negative pressure chamber 102, the diaphragm 101 and the rod 10 fixed to the diaphragm 101 are
It is designed to move 4. In the figure, above the diaphragm 101 in the negative pressure chamber 102,
Recess 1 into which the tip of the first nipple 108 can fit
A valve body 106 made of an elastic material having a diameter of 0.05 is provided, and an annular seal portion 107 that projects annularly is provided at the open end of the valve body 106. On the other hand, above the valve body 106, a first nipple 108 for introducing negative pressure into the negative pressure chamber 102 is attached to the housing 100. It is designed to engage with or separate from the seal portion 107. Furthermore, a second nipple 109 is attached to the housing 100 for introducing negative pressure into the negative pressure chamber 102 from another negative pressure source.

An actuator with such a configuration first has a first
When the diaphragm 101 is moved to the negative pressure chamber 102 side by introducing negative pressure from the nipple 108 of the first
At the stage when the tip of the first nipple 108 engages with the seal portion 107, the negative pressure introduction passage 108a of the first nipple 108 is closed and the diaphragm 101 stops. Furthermore, by introducing negative pressure from the second nipple 109, the diaphragm 101 further moves toward the negative pressure chamber 102, and the tip of the first nipple 108 pushes the seal portion 107 apart and slides while maintaining the sealed state. However, when the tip of the first nipple 108 comes into contact with the bottom surface of the recess 105 of the valve body 106, it stops. In this way, only one diaphragm 101 is used to change the stroke of the rod in two stages.

(Problems to be Solved by the Invention) However, in the case of such a conventional example, concentricity between the seal portion 107 of the valve body 106 and the first nipple 108 that engages with the seal portion 107 is required. ,
Since the valve body 106 and the first nipple 108 are separated, it has been difficult to center the valve body 106 and the first nipple 108. If concentricity is not achieved, the axes of the valve body 106 and the first nipple 108 will be misaligned, resulting in poor sealing performance between the seal portion 107 and the tip of the nipple, and the pressure difference between the atmospheric chamber 103 and the negative pressure chamber 102 will be reduced to a predetermined level. Therefore, there was a problem that the stroke of the rod 104 did not reach a predetermined amount, and the control characteristics of controlled parts such as the throttle valve of the actuator became unstable. There was also the problem that repeated operations caused uneven wear and reduced durability.

The present invention was made in order to solve the problems of the prior art, and its purpose is to meet the precision requirements for concentricity between the nipple and the valve by providing a constant valve part on the nipple side. The object of the present invention is to provide an actuator with improved properties and improved durability.

(Means for solving the problem) Therefore, in order to achieve the above purpose, the present invention
A diaphragm is attached to the housing to form a negative pressure chamber and an atmospheric chamber, and the housing is provided with a nipple having a negative pressure introduction path for introducing negative pressure from a negative pressure source into the negative pressure chamber, and the negative pressure chamber is In the actuator that reciprocates a rod fixed to the diaphragm due to the differential pressure between the rod and the atmospheric chamber, the nipple projects into the negative pressure chamber to form a protruding part, and the protruding part is arranged opposite to the diaphragm. A cylinder chamber that opens is provided, and a negative pressure control valve for opening and closing the negative pressure introduction path is installed in the cylinder chamber, and the negative pressure control valve is a valve part that is inserted into the cylinder chamber so as to be able to reciprocate. , and a valve seat provided at a rear end of the cylinder chamber, the protruding end of the valve portion protruding from the opening of the cylinder chamber toward the diaphragm comes into contact with the diaphragm, and the protruding end of the valve portion An end opposite to the end is brought into contact with and separated from a valve seat at the rear end of the cylinder chamber to open and close the negative pressure introduction path.

(Function) In the actuator having the above configuration, when negative pressure is introduced through the negative pressure introduction path, the differential pressure between the atmospheric chamber and the negative pressure chamber becomes large, and the diaphragm is bent toward the negative pressure chamber. , the rod fixed to the diaphragm moves. Further, due to the deflection of the diaphragm, the valve portion that is in contact with the diaphragm moves in a direction from the opening side of the cylinder chamber to the back side.

When the back end of the valve part contacts the valve seat and the negative pressure introduction path is closed, no further negative pressure is introduced into the negative pressure chamber, the diaphragm stops, and the rod also stops moving.

Furthermore, when the negative pressure is eliminated, the diaphragm returns from the negative pressure chamber side to the atmospheric chamber side, and the rod also returns accordingly. Further, in the negative pressure control valve, the valve portion moves in a direction protruding from the cylinder chamber following the movement of the diaphragm.

The movement of the valve part in a negative pressure control valve follows the movement of the diaphragm with which its protruding end comes into contact.
Since they are simply in contact with each other, even if the contact position between the valve part and the diaphragm shifts, the positional relationship between the valve part and the valve seat remains constant, and the valve seat remains constant. Opening/closing control is performed smoothly.

(Example) The present invention will be explained below based on the illustrated example. FIG. 1 and FIG. 2 show an actuator according to this embodiment, and 1 is a first housing;
Reference numeral 2 denotes a second housing, and the outer peripheral edge of the diaphragm 3 is sandwiched between the opening edges 1a and 2a of the first housing 1 and the second housing 2.
A negative pressure chamber 4 is formed by the diaphragm 3 and the diaphragm 3, and is maintained airtight. On the other hand, diaphragm 3 and diaphragm 2
An atmospheric chamber 5 is formed between the housing 2 and the housing 2 . A center hole 5a is provided in the center of the second housing 2.
is provided, and a rod 6 fixed to the diaphragm 3 is inserted therethrough. The rod 6 is connected to the controlled section 6' to control the controlled section 6'. The diaphragm 3 is held between its upper and lower surfaces by a plate-shaped upper retainer 7a and a lower retainer 7b, and the above-mentioned rod 6 is fastened together with the upper retainer 7a and lower retainer 7b.

The first housing 1 includes a first nipple 9 and a second nipple that introduce negative pressure into the negative pressure chamber 4 from separate first, second, and third negative pressure sources 8a, 8b, and 8c, respectively. 10 and a third nipple 11 are provided. The first nipple 9 and the second nipple 10 extend vertically on the upper surface of the first housing 1 in the figure and protrude into the negative pressure chamber 4 .
The protrusions 9', 10' have negative pressure introduction passages 9a, 1
A cylinder chamber 12 communicating with Oa is provided. Negative pressure introduction passages 9a and 1 are provided in the cylinder chamber 12.
A negative pressure control valve 13 that controls opening and closing of 0a is incorporated.

To explain the negative pressure control valve 13 using the first nipple 9 as an example, as shown in an enlarged view in FIG. 2, the negative pressure control valve 13 is inserted into the cylinder chamber 12 so as to be able to reciprocate. It has a configuration including a valve portion 13a and a valve seat 17 provided at the rear end of the cylinder chamber 12. The valve portion 13a is connected to the cylinder chamber 1.
a valve body 16 on the protruding end side protruding from the opening of No. 2;
A valve head 15 is provided at the opposite end of the valve body 16 and closes and separates from the valve seat 17 to open and close the negative pressure introduction path 9a. The valve head 15 includes a disk-shaped valve head main body 15a slidably inserted into the cylinder chamber 12, and a spring 1 connecting the valve head main body 15a with the valve body 16.
4, and can be expanded and contracted by elastic deformation of a spring 14. The valve body 16 is a disc-shaped spring receiver 16a that is slidably inserted into the cylinder chamber 12 facing the valve head main body 15a.
, a disk-shaped portion 16b that has a larger diameter than the inner diameter of the first nipple 9 and contacts the diaphragm 3 via the spring retainer 7a, and a small-diameter connecting portion 16c that connects the spring receiver 16a and the disk-shaped portion 16b. It consists of. A notch 15b is formed at the circumferential end of the valve head main body 15a as an air passage. The cutout 15b may be provided at one location or at multiple locations. Also, the notch 15b is smaller than the width of the annular valve seat 17 due to the step with the negative pressure introduction passage 9a at the rear end of the cylinder chamber 12, and the valve head main body 15a is smaller than the width of the valve seat 17.
7, the notch 15b is closed by the valve seat 17. Also, the spring receiver 16 of the valve body 16
A notch 16d serving as an air passage is also formed at the outer peripheral end of the holder. This notch 16d is also notch 15
Similarly to b, they may be provided at a plurality of locations, and the negative pressure introduction passage 9a and the negative pressure chamber 4 are communicated through this notch 16d and the above-mentioned notch 15b.

The lower surface of the disc-shaped portion 16b of the valve body 16 is in contact with the upper surface of the spring retainer 7 of the diaphragm 3, and the spring receiver 16a and the valve head 15 are inserted into the cylinder chamber 12, and the inside of the cylinder chamber 12 is moved by the operation of the diaphragm 3. It is designed to slide.

On the other hand, the negative pressure control valve 13 inserted into the second nipple 10 has the same structure as the one inserted into the first nipple 9, but the length of the part protruding into the negative pressure chamber 4 is It is longer than the first nipple 9, and the valve seat of the cylinder chamber 12 is located closer to the diaphragm 3 than the second nipple 10.

Further, the third nipple 11 is provided on the side surface of the first housing 1, and no negative pressure control valve is provided.

In the actuator having the above configuration, first,
The second and third nipples 9, 10 and 11 are each connected to a separate negative pressure source. FIG. 3A shows a free state of the actuator, in which no negative pressure is introduced from any of the first, second, and third nipples 9, 10, and 11, and the negative pressure chamber 4 This shows a case where no pressure difference occurs between the air chamber 5 and the atmospheric chamber 5.

FIG. 3B shows the first step, in which the first and third nipples 9, 11 are closed and the second negative pressure source 8b is
A negative pressure is introduced from the second nipple 10 through the second nipple 10 . Then, due to the pressure difference between the negative pressure chamber 4 and the atmospheric chamber 5, the diaphragm 3 is sucked upward in the diagram.
Following this, the valve body 16 enters into the cylinder chamber 12, the valve head main body 15a abuts the valve seat 17 at the far end of the cylinder chamber 12, the notch 15b is closed, and it stops at that position. This constitutes the first stroke _L1 of the rod 6.

FIG. 3C shows the second step, in which negative pressure is introduced from the first negative pressure source via the first nipple 9 in the state shown in FIG. Then, the diaphragm 3 rises again, and the valve head main body 15a comes into contact with the valve seat 17 at the far end of the cylinder chamber 12 of the first nipple 9, and the notch 15b
It will stop when it is closed. At this time, the negative pressure control valve 13 provided in the second nipple 10 is compressed by the valve body 16 that moves following the diaphragm 3. This is the second stroke of Rod 6
It becomes L ₂ .

FIG. 3D shows the third step, in which the negative pressure introduced from the third negative pressure source 8c through the third nipple 11 in the state shown in FIG. The upper surface of the 16 disc-shaped portion 16b is the second
It moves until it comes into contact with the distal end surface 10b of the nipple 10, and stops when it comes into contact with it. This is Rod 6
The third stroke is _L3 .

Note that rubber or the like may be attached to the upper surface of the disc-shaped portion 16b or the contact portion with which the second nipple 10 contacts in order to improve sealing performance.

In the above explanation, we have explained the switching of three steps, but the first step is omitted and the first step is changed.
Negative pressure may be introduced first from the negative pressure source 8a to switch between two stages, the second stroke and the third stroke, or the first and second steps may be omitted to make the stroke length only one stage. You can also do it.

Furthermore, in this embodiment, a three-stage actuator in which the rod moves in three stages is shown, but the number of nipples may be changed depending on the number of negative pressure sources.
It is also possible to control in stages or in three or more stages.

Furthermore, the stroke of the rod can be adjusted by fixing the first and second nipples 9 and 10 to the first housing 1 by screwing or the like and making the amount of protrusion of each nipple into the negative pressure chamber 4 variable. be able to.

(Effects of the invention) The present invention consists of the above structure and operation,
The negative pressure control valve is integrated into the cylinder chamber formed in the protruding part of the nipple that protrudes into the negative pressure chamber, and the structure is such that the protruding end of the valve part simply contacts the diaphragm, thereby preventing contact between the diaphragm and the valve part. Even if the position shifts, the positional relationship between the valve part and the valve seat can be maintained constant, eliminating the conventional requirement for precision in concentricity between the valve part and the valve seat, and making the stroke amount of the rod stable. Therefore, controlled parts such as engine valves can be accurately controlled.

In addition, there is no need to perform centering work between the valve portion and the valve seat as in the prior art, and the valve seat can be manufactured extremely easily.

Furthermore, since uneven wear due to axial misalignment between the valve portion and the valve seat does not occur as in the conventional case, durability can be improved.

[Brief explanation of the drawing]

Fig. 1 is a partial front cross-sectional view of an actuator according to an embodiment of the present invention, Fig. 2 is an enlarged front cross-sectional view of the negative pressure control valve of the device shown in Fig. 1, and Fig. 3 A, B, C, and D are FIG. 1 is an enlarged cross-sectional view of the tip of each nipple showing the position of the valve body of each nipple during operation of the device of FIG. 1, and FIG. 4 is a partial front cross-sectional view of a conventional actuator. Explanation of symbols: 1...First housing, 3...Diaphragm, 4...Negative pressure chamber, 5...Atmospheric chamber, 6...
...rod, 9...first nipple, 10...second
Nipple, 11...Third nipple, 9a, 1
0a, 11a... Negative pressure introduction passage, 12... Cylinder chamber, 13... Negative pressure control valve, 13a... Valve section, 1
4... Spring, 15... Valve head, 15a... Valve head body, 16... Valve body.

Claims (1)

[Claims for Utility Model Registration] A diaphragm is attached to a housing to form a negative pressure chamber and an atmospheric chamber, and the housing has a negative pressure introduction path for introducing negative pressure from a negative pressure source into the negative pressure chamber. In an actuator that is provided with a nipple and reciprocates a rod fixed to the diaphragm by a pressure difference between the negative pressure chamber and the atmospheric chamber, the nipple is made to protrude into the negative pressure chamber to form a protrusion, and the protrusion A cylinder chamber opening facing the diaphragm is provided in the cylinder chamber, and a negative pressure control valve for opening and closing the negative pressure introduction passage is built into the cylinder chamber, and the negative pressure control valve is reciprocated into the cylinder chamber. The valve part is configured to include a movably inserted valve part and a valve seat provided at a rear end of the cylinder chamber, and a protruding end of the valve part that protrudes from the opening of the cylinder chamber toward the diaphragm comes into contact with the diaphragm. and an end of the valve portion opposite to the protruding end is moved toward and away from a valve seat at a rear end of the cylinder chamber to open and close the negative pressure introduction path.