JPS62220768A - Bellows - Google Patents

Abstract

PURPOSE:To prevent the abrasion due to contact by integrally molding a thick contact part onto a bendable part which projects to the low pressure side. CONSTITUTION:A thick contact part 21 is integrally molded at the bendable part 19A projecting onto a negative pressure space 13 side as the low pressure side. The contact part 21 is formed so as to prevent the contact due to the expansion in the case when the bellows 18 contracts. With such constitution, when the bellows 18 contracts, even if the bendable part 19A is expanded outwardly by the pressure difference between the negative pressure space 13 and a space 17, the contact part 21 keeps the interval, and the mutual contact of the bellows 18 is prevented.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a bellows that is used to partition and seal two chambers in which a pressure difference exists, and more specifically, the present invention relates to a bellows that is used to partition and seal two chambers in which a pressure difference exists, and more specifically, This invention relates to a bellows that prevents the wear and tear that occurs.

(Prior Art) There is a bellows used in a diamond 7 ram actuator as a bellows that separates and seals two chambers where there is a pressure difference.

As shown in FIG. 3, the bellows 1 used in the conventional diamond 7 ram actuator has bent parts 2A and 2B that protrude inwardly and outwardly.These bent parts 2A and 2B allow for expansion and contraction. There is.

However, since the material constituting the bellows 1 is made of a flexible material such as synthetic resin or synthetic rubber, the bellows 1 may warp or bulge due to the pressure difference, causing the bellows 1 to deform abnormally. Abnormal deformation due to distortion or bulge of the bellows 1 is mainly caused by the bulge of the bent portion 2B protruding toward the high pressure side.

Therefore, in the conventional bellows 1, a ring 3 made of metal or hard synthetic resin is disposed around the outer periphery of the bent portion 2B protruding toward the high-pressure side to prevent the bent portion 2B from bulging.

In this way, the abnormal deformation of the bellows 1 is mainly caused by the swelling of the bent portion 2B that protrudes toward the high pressure side, so it is necessary to strengthen the bent portion 2B with the ring 3 and thereby prevent the abnormal deformation of the bellows 1. It was something to do.

(Problems to be Solved by the Invention) However, the conventionally known bellows 1 described above has the following drawbacks.

Referring to FIG. 4, deformation of the bellows 1 also occurs under the following conditions. That is, when the bellows 1 contracts, the pressure difference causes the bent portion 2A side to expand just like a balloon, causing the contact portions shown at 4 in the figure to rub against each other and cause abrasion, resulting in poor sealing due to abrasion. was.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a bellows which eliminates the above-mentioned drawbacks and reliably prevents sealing defects with a simple structure.

(Means for Solving the Problems) The retainer of the present invention is provided by integrally molding the contact portion of the meat 17 on the bent portion protruding to the low pressure side, thereby preventing wear due to contact. There it is.

(Example) Hereinafter, an example of the present invention will be described with reference to Figures f51 and 12.

In this embodiment, the bellows used in the diamond 7 ram actuator will be described below, but the bellows of the present invention is not limited to its application.

The seven-diameter ram actuator has a casing 11 partitioned into a negative pressure space 13 and an atmospheric pressure space 14 by a diaphragm 12 . In order to introduce negative pressure into the negative pressure space 13,
A negative work introduction boat 15 is provided. Diaphragm 1
A rod 16 is fixed to 2, and is reciprocated by the balance between negative pressure and a spring 17.

An expandable bellows 18 is provided to reciprocate the rod 16 and at the same time partition the negative pressure space 13 from the space 17 in which the rod 16 is disposed. Bellows 1
8 has one end attached to the diaphragm 12 and the other end attached to the casing 11
is fixed in a sealed manner.

In order to make the bellows 18 expandable and retractable, the bellows 18 has bent portions 19A and 19B that protrude inwardly and outwardly.

Since there is a pressure difference between the inside and outside of the bellows 18 used in the Diamond 7 ram actuator, the bent portion 19113 protruding toward the space 17 side, which is the high pressure side (atmospheric pressure), causes abnormal deformation such as bulge. . Therefore, a ring-shaped reinforcing portion 20 is integrally formed on the bent portion 19B. Note that the ring-shaped reinforcing portion 20 is not necessarily necessary in the present invention, and includes a structure in which a conventionally known ring is used to prevent swelling.

In the present invention, the bellows 18 has the following configuration.

A thick abutment portion 21 is integrally formed on the bent portion 19A that protrudes toward the negative pressure space 13 side, which is the low pressure side. Contact part 21
may be provided around the circumference a of the bent portion 19A, but since it is sufficient to prevent contact due to the bulge when the bellows 18 is contracted, it is sufficient to have a structure in which the bellows 18 is provided partially, for example at four locations every 90 degrees. It is something. Note that the present invention does not exclude a configuration in which the contact portion 21 is provided all around the circumference.

Here, the wall thickness of the portion of the bellows 18 excluding the bent portions 19A and 19B is approximately 0.7 mm, and the thickness of the contact portion 21 is preferably approximately 5 mm. It is not limited to the numerical value, and the numerical value may be freely selected as long as it maintains a sufficient distance without contact or rubbing near the bent portion 19A.

In the above description, the material of the bellows 18 is made of flexible synthetic resin or synthetic rubber.

Since the present invention is configured as described above, the bellows 1
When the bellows 8 contract, even if the bent portion 19A bulges outward due to the pressure difference between the negative pressure space 13 and the space 17, the contact portion 21 maintains the same position, so the bellows 18 are prevented from coming into contact with each other and rubbing against each other. It is something that will disappear.

Note that the above configuration is one embodiment of the present invention, and the present invention is not limited to the above embodiment.

The present invention also includes a bellows that is used to separate and seal a side with a higher pressure than the inlet pressure and the outside air (atmospheric pressure).

Further, the reinforcing portion is not necessarily a necessary structure and may be omitted. Further, a conventionally known reinforcing ring may be provided instead of the reinforcing portion. That is, the present invention suffices as long as it has a 415 structure in which at least the bent portion protruding toward the low pressure side has an abutting portion that maintains the interval.

(Effects of the Invention) The effects of the present invention, which is constructed and operated as described above, are as follows.

Since there is no rubbing caused by the bellows' bulge, wear is prevented, improving durability and reliability.

A configuration in which a contact portion is partially provided is low cost;
And I like the lightweight bellows! I can do that.

Since the ring-shaped reinforcing part is integrally molded on the bent part 19B, the structure is simple, and the assembly work is also simple, resulting in a cost-effective product.

In addition, the position of the ring 3 does not shift as in the conventional case,
This makes it possible to reliably prevent abnormal deformation.

Furthermore, the number of parts is reduced, making parts management simple and hassle-free.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a diamond 7 ram actuator showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the bellows shown in FIG. 1, and FIG. 3 is a conventionally known diamond 7 ram actuator. The cross-sectional view, Figure 4 is! ¥13 It is an enlarged sectional view of the bellows portion of the figure. 18: Bellows 19A, 19B: Bent portion 20: Reinforcement portion 21: Contact department Patent attorney Mibe Tsuji (1 person) Figure 1 Figure 2 ζ Figure 3 Figure 4

Claims (1)

[Claims] In a bellows that has a bent part that protrudes inwardly and outwardly and is used to partition and seal two chambers where a pressure difference exists, a thick abutting part is integrated all around or partially with the bent part that protrudes toward the low pressure side. Bellows is characterized by being molded.