JPS629007A - Actuator - Google Patents

Abstract

PURPOSE:To compact an actuator, by forming two turnup portions on a diaphragm, partitioning two pressure chambers on both sides of the diaphragm, and providing reversal preventing portions in a housing and on an output shaft. CONSTITUTION:A diaphragm 6 is provided between an output shaft 5 and a housing 1 to partition and form a first pressure chamber 7 and a second chamber 8. The diaphragm 6 is provided with a first turnup portion 6a and a second turnup portion 6b, a cup-shaped member 3 is provided with a reversal preventing portion 2a, and a large diameter portion 5a is provided with a reversal preventing portion 5c. Above-mentioned output shaft 5 is moved left and right with the same energizing power and large displacement quantity of the output shaft is ensured easily by means of each turnup portion, so that miniaturization of axial direction size can be attempted.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an actuator, and more particularly to an actuator in which a pressure chamber is defined using a diaphragm.

``Prior Art'' Conventionally, actuators have been constructed such that a pressure chamber is formed by partitioning the inside of a housing with a diaphragm, an output shaft is connected to the diaphragm, and the output shaft is actuated by the fluid pressure introduced into the pressure chamber. are widely used in general.

``Problems to be Solved by the Invention'' However, actuators using a diaphragm usually operate the output shaft in only one direction, and a spring is normally used for returning the output shaft. Of course, 1
Although it is possible to form pressure chambers on both sides of each diaphragm and cause the output shaft to reciprocate by using fluid pressure supplied to and discharged from each pressure chamber, in this case, it is necessary to ensure a large amount of displacement of the output shaft. becomes difficult. In addition, if the output shaft is a single rod, that is, if the output shaft passes through only one pressure chamber, there will be a difference in the pressure receiving area on both sides of the diaphragm by the cross-sectional area of the output shaft. There was also the problem that the acting forces for reciprocating the shaft were different.

Therefore, when it is necessary to reciprocate the output shaft using pressure fluid, two diaphragms are usually connected to the output shaft so that each diaphragm forms two pressure chambers. The number of parts increases,
Furthermore, there was a drawback that the axial dimension also became large.

"Means for Solving the Problems" In view of such circumstances, the present invention provides an output shaft slidably within a housing, and includes a first folded back extending substantially along the axial direction of the output shaft at one end of the diaphragm. The free end portion forward of the first folded portion is connected to the housing, and the first folded portion is connected to the other end of the diaphragm.
A second folded part extending in the opposite direction to the folded part is formed, a free end portion in front of the second folded part is connected to the output shaft, and a first pressure chamber and a second pressure chamber are formed on both sides of the diaphragm, respectively. Further, the housing and the output shaft are provided with an inversion prevention part located inside each of the folded parts to prevent each folded part from being reversed.

"Function" According to such a configuration, it is easy to secure a large displacement amount of the output shaft by each of the above-mentioned folded parts, and since only one diaphragm is required, the number of parts can be reduced and the axial dimension can be made smaller. can be achieved. Also, if necessary, by taking advantage of the fact that the effective diameters on both sides of the diaphragm are different,
By using a single-rod type output shaft with different pressure-receiving areas on both sides, and using the difference in pressure-receiving areas to offset the difference in the effective diameter of the diaphragm, the output shaft can move forward and backward with substantially the same acting force. It becomes possible to move it.

``Embodiment'' The present invention is deducted for the illustrated embodiment below.The housing 1 is composed of two cup-shaped members 2.3 having different inner diameters, and the open end of each cup-shaped member 2.3 is abutted. A sealed container is constructed by connecting them with a port 4. An output shaft 5 is slidably provided in the housing 1. A diaphragm 6 is stretched between the output shaft 5 and the housing 1, and a first pressure chamber 7 and a second pressure chamber are provided in the housing 1. The chamber 8 is partitioned.

The diaphragm 6 is cylindrical in its natural state,
By folding the left end of the cylindrical diaphragm 6 outward, a first folded portion 8a extending substantially along the axial direction of the output shaft 5 is formed, and a free end portion forward of the first folded portion 6a is formed. is held airtightly between the abutting portions of the two cup-shaped members 2.3.

At this time, a cylindrical shape that fits into the inside of the large-diameter cup-shaped member 3 with a gap equal to the thickness of the diaphragm 6 from the inner peripheral surface of the large-diameter cup-shaped member 3 is provided at the opening end of the small-diameter cup-shaped member 2. A reversal prevention portion 2a is integrally formed, and this reversal prevention portion 2a is located inside the first folded portion 8a to prevent the first folded portion 8a from being reversed.

On the other hand, the right end of the diaphragm 6 is folded inward to form a second folded part 6 extending in the opposite direction to the first folded part 8a.
b, and the free end portion in front of the second folded portion 6b is connected to the large diameter portion 5a of the output shaft 5, and the diaphragm 6 and the large diameter portion 5a of the output shaft 5 form the above-mentioned A first pressure chamber 7 and a second pressure chamber 8 are partitioned.

The large diameter portion 5a of the output shaft 5 has a cylindrical portion 5b extending to the left in the axial direction and a cylindrical reversal prevention portion 5 extending to the right on its outer periphery.
A cylindrical stopper member IO is fitted into the right side of the inversion prevention portion 5C and fixed to the output shaft 5 with a snap ring 11. The second folded part 6b is folded back so as to surround the right side inversion prevention part 5c,
The free end portion in front of the folded portion 8b is clamped and fixed between the large diameter portion 5a and the stopper member 10.

Furthermore, in this embodiment, the diaphragm effective diameter D1 on the first pressure chamber 7 side is different from the diaphragm effective diameter D1 on the second pressure chamber 8 side.
2, the output shaft 5 is made into a single-rod type and is slidably protruded from only the first pressure chamber 7 side to the outside of the housing l, and the cross-sectional area A of the output shaft 5 is set to be larger than the first pressure chamber 7 side. The pressure receiving area on the pressure chamber 7 side and the pressure receiving area on the second pressure chamber 8 side are set to be substantially equal (πD, 2/4−A=πD22/4).

In addition, a groove 12 is formed along the axial direction on the surface of the inversion prevention part 2a that the diaphragm 6 is in close contact with to prevent the diaphragm 6 from sealing the pressure fluid, and for the same purpose, the other inversion prevention part is 5c is formed with an axial hole 13 that penetrates inside the second folded portion 8b of the diaphragm 6. Note that the groove 12 is provided in the reversal prevention portions 2a and 5C.
It goes without saying that the holes 13 and 13 may be formed in the opposite manner, or both may be formed the same way, and as other means, grooves, ribs, etc. may be provided in the diaphragm 6.

In the above configuration, when pressure fluid is supplied to the first pressure chamber 7 and pressure fluid is discharged from the second pressure chamber 8, the diaphragm 6 is moved to the
The output shaft 5 is deformed by receiving a biasing force to the left from the pressure introduced into the pressure chamber 7, and the second folded portion 8b is prevented from being reversed by the reversal prevention portion 5C provided on the output shaft 5. Move to the left.

On the other hand, pressure fluid is supplied to the second pressure chamber 8, and the first pressure chamber 7
When the pressure wave body is discharged from the housing, the diaphragm 6 is deformed by the biasing force to the right due to the pressure introduced into the second pressure chamber 8, as shown in the upper half of the center line of the figure. The output shaft 5 is moved to the right while the first folded portion 8a is prevented from being reversed by the reversal prevention portion 2a provided at the end.

In this embodiment, the output shaft 5 is moved leftward or rightward with the same biasing force, and the supply of pressure fluid to each pressure chamber 7.8 is switched, so that the biasing force of the diaphragm 6 is reversed. When this occurs, since the grooves 12 and holes 13 are formed in the inversion prevention portions 2a and 6b, respectively, it is possible to prevent the diaphragm 6 from sealing the pressure fluid.

In the above embodiment, the output shaft 5 is of a single rod type, but it goes without saying that it may be of a double rod type as shown by the imaginary line in the figure.

"Effects of the Invention" As described above, according to the present invention, it is easy to ensure a large amount of displacement of the output shaft by each folded portion, and since only one diaphragm is required, the number of parts can be reduced and The effect is that the size can be reduced.

[Brief explanation of the drawing]

The figure is a cross-sectional view showing an embodiment of the present invention, with the upper half and the lower half of the center line shown in different operating directions. l... Housing 2a... First reversal prevention part 5
...Output shaft 5C...Second reversal prevention part 6.
...Diaphragm 6a...First folded part 6b...
・Second folding part 7...First pressure chamber 8...Second pressure chamber

Claims (2)

[Claims] (1) An output shaft is slidably provided in the housing, a first folded portion extending substantially along the axial direction of the output shaft is formed at one end of the diaphragm, and a free end portion in front of the first folded portion is formed. A second folded part is formed at the other end of the diaphragm and extends in a direction opposite to the first folded part, and a free end portion in front of the second folded part is connected to the output shaft. , a first pressure chamber and a second pressure chamber are defined on both sides of the diaphragm, and a first pressure chamber and a second pressure chamber are formed on both sides of the diaphragm, and a first pressure chamber and a second pressure chamber are formed between the housing and the output shaft, and the housing and the output shaft are provided with a pressure chamber located inside each of the folded parts so that each folded part is inverted. An actuator characterized by being provided with a reversal prevention section that prevents reversal. (2) The effective diameter of the diaphragm on the first pressure chamber side is set larger than the effective diameter of the diaphragm on the second pressure chamber side, and the output shaft protrudes outside the housing only from the first pressure chamber side. The effective pressure receiving area on the pressure chamber side and the second
The actuator according to claim 1, wherein the pressure receiving area on the pressure chamber side is set to be substantially equal.