JPH0599153A - Bellows type fluid forced feed device - Google Patents

Abstract

PURPOSE:To reduce local fatigue of a material owing to repetition of a stress by forming a bellows such that the bellows are welded in a meandering state by using the different numbers of bellows. CONSTITUTION:In a bellows type fluid forced feed device, through drive rotation of a pulley 12, an eccentric shaft part 13 is eccentrically rotated, a bellows 4 is expanded and contracted by vertical movement of a moving support 6 through a roller 20 and a rod 8, and fluid sucked through a suction valve 22 by expansion and contraction of the bellows is delivered as a delivery valve 23 is forcibly opened. In this case, the bellows 4 is formed such that the different numbers of bellows are welded in a meandering state. Namely, a bellows part 4a where a deformation amount of the bellows 4 is low is formed of one bellows and bellows parts 4b and 4c where a deformation amount is high are formed of two or three bellows each having thickness lower than that of the bellows part 4a. This constitution causes the parts 4b and 4c to reduce the occurrence of local material fatigue.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bellows type fluid pressure feeding device used for, for example, a compressor, a pump, a reciprocating actuator and a valve.

[0002]

2. Description of the Related Art In this type of fluid pumping device, the fluid is taken in and out by expanding and contracting the bellows, which is conventionally changed by the reciprocating motion of the bellows housed in the casing. It is used to pump the fluid. As the velocities used at this time, velocities having a constant plate thickness and formed at equal pitches were used.

Since such a fluid pressure feeding device has a simple structure as compared with a vane, a piston, etc., it has been used as a large capacity compressor, pump, actuator or the like in a low speed operation range.

[0004]

However, in this type of fluid pumping device, the stress applied to the material due to the bending due to the expansion and contraction of the bellows and the stress due to the pressure of the fluid cause the material to fatigue due to the repetition of these stresses. The life is shortened.

Also, paying attention to the movement of the bellows, due to the mass and spring constant of the bellows, the pitches of the fixed side and the movable side of the bellows do not move evenly during high speed operation, and the fixed side does not move. Since the pitch becomes narrower and the deformation of this portion becomes larger, the stress of the bellows increases and the life of the bellows becomes shorter.

Therefore, the present invention provides a bellows type fluid pressure feeding device which can improve the life by constructing the bellows of a portion which is deformed a lot by combining a plurality of bellows. The purpose is.

[0007]

As a means for solving the above-mentioned problems, the present invention uses one end of a bellows as a casing.
A fluid pressure-feeding device, which is attached to a cloth and the other end of which is reciprocally movable, is formed by welding a different number of the bellows in a zigzag shape. Further, in the above-mentioned belouse, the belouse with a large number of sheets is formed to have a thinner plate thickness than the belouse with a large number of sheets.

[0008]

[Operation] By forming the velocities by welding in a zigzag shape with different numbers of sheets, it is possible to overlap and weld multiple velocities of the part with a large amount of deformation. Local material fatigue can be reduced and life can be extended. In particular, according to the second aspect, the velocities with a large number of sheets are formed so that the velocities with a large number of sheets are thinner than those with a small number of sheets, so that the reciprocating movement of the veloces is smooth. By repeating the stress, local material fatigue can be eliminated.

[0009]

EXAMPLES Next, one example of a bellows type fluid pressure feeding device of the present invention will be described with reference to the drawings. FIG. 1 is a vertical sectional view of an embodiment of the present invention.

In FIG. 1, a case 1 and a valve case 2 are provided.
A casing 4 formed by and contains a bellows 4. The bellows 4 has a ring-shaped fixed support 5
And a disk-shaped movable support 6 projecting inward at the central portion of the casing and a chamber 7 between the valve case 2 and the movable support 6 in the casing 3. Is defined.

The fixed support 5 is fixed to the valve case, and the movable support 6 has a nut 1 at the tip of a rod 8.
5 is fixed, and the bellows 4 is moved by the vertical movement of the rod 8.
Expands and contracts, and the volume of the chamber 7 changes.

The rod 8 is supported at its both ends by a boss 16a of a support 16 fixed to the case 1 and a hole 17 of the case 1 so as to be slidable in the vertical direction. The input shaft 9 is rotated to move up and down.

The input shaft 9 is rotatably supported by bearings 10 and 11 mounted on the case 1, and a prime mover (not shown) is mounted through a pulley 12 mounted on one end of the input shaft 9. Is linked to.
At the other end of the input shaft 9, the bearing 1
A shaft portion 13 eccentric with respect to the shaft center supported by 0, 11 is provided, and the rotation of the input shaft 9 causes the shaft portion 13 to rotate.
The roller 20 is rotated and oscillated via a bearing 14 provided in the.

Further, the rod 8 is provided with a window portion 18 on which a roller 20 can slide, and the window portion 18 is provided with a window 2.
By arranging 0, the rod 8 and the input shaft 9 are connected.

The input shaft 9 is rotated by driving the pulley 12 with a prime mover, and the shaft portion 13 is rotated around the axis of the input shaft 9 in accordance with this rotation. The rotation of the shaft 13 is
The roller 20 moves vertically while swinging with the roller 20 via the bearing 14, and the roller 20 itself also slides in the window 18 in the horizontal direction.

The vertical movement of the roller 20 drives the rod 8 in the vertical direction. The movement of the rod 8 is transmitted to the bellows 4 via the movable support 6, and the bellows 4 expands and contracts.

At this time, the bellows 4 is in the maximum compression state when the movable support 6 is at the upper limit position (shown by the two-dot chain line in the figure), and the movable support 6 is at the lower limit position (the solid line in the figure). (Indicated by), the maximum tensile state is reached.

The volume of the chamber 7 changes as the bellows 4 expands and contracts, and the fluid in the chamber 7 has a suction valve 22 attached to a suction port 19 of the case 1 and a discharge port of the case 1. It is designed to be sucked and discharged by a discharge valve 23 attached to the port 21.

FIG. 2 is a view showing an embodiment of the bellows, in which the bellows 4 are different in number and are welded in a zigzag shape.

The bellows portion 4a of the bellows 4 having a small amount of deformation is composed of a single bevel and has a large amount of deformation.
The claw portions 4b and 4c are composed of two or three claws which are thinner than the claw portion 4a.

With this structure, the stress due to the deformation of the portion 4a of the bellows 4 having a large amount of deformation can be reduced, and the stress can be reduced by the pressure of the two or three bellows. It can be reduced and the life can be improved.

[0022]

As described above, according to the present invention, local fatigue of a material due to repeated stress can be reduced by superposing and welding a plurality of velocities in a portion having a large deformation. Therefore, it is possible to provide the bellows type fluid pressure feeding device which can prolong the life. In particular, by forming the velvet with a large number of sheets so that the plate thickness of the velvet is thinner than that with a small number of velocities, the reciprocating movement of the velocities is made smooth and stress is reduced. It is possible to eliminate local material fatigue due to repetition of.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of a bellows type fluid pressure feeding device of the present invention.

FIG. 2 is a sectional view of an essential part of an embodiment of the bellows of the present invention.

[Explanation of symbols]

 4 Bellows 4a Bellows part 4b Bellows part 4c Bellows part

Claims (2)

[Claims] 1. A fluid pressure feeding device in which one end of a bezel is attached to a case and the other end is attached so as to be reciprocally movable. A bellows type fluid pressure feeding device, which is constructed by welding in a zigzag shape. 2. The bellows according to claim 1, wherein the bellows having a larger number of sheets are formed to have a thinner plate thickness than the bellows having a larger number of sheets than the bellows having a small number of sheets. -Type fluid pumping device.