JPH0788903B2 - Method for manufacturing diaphragm having uneven multi-groove structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a diaphragm whose flexibility is remarkably increased by providing an uneven multi-groove structure.

Elastomeric sheets are commonly known as highly flexible sheets.

This is because the sheet has a lower elastic modulus than other materials and thus the sheet is easily bent, and the sheet can be deformed by stretching with a force smaller than that of the other materials.

However, even in a thin elastomer sheet, the force required for bending deformation and the force required for stretching deformation are significantly different.

When flexibility is required in the elastomer sheet for deformation accompanied by stretching, if a large number of concave and convex groove structures are provided in the direction perpendicular to the stretching direction, the accordion type mechanism bends and transforms the stretch conversion of the elastomer sheet. Can be converted to.

This stretches the elastomeric sheet with a small force and significantly increases the flexibility of the elastomeric sheet.

TECHNICAL FIELD The present invention relates to a method for manufacturing a diaphragm having an uneven multi-groove structure and having high flexibility.

[Prior Art] Usually, when it is attempted to manufacture a diaphragm having such an uneven multi-groove structure, between a mold having a pair of uneven multi-groove rib surfaces having a space matching the diaphragm is usually used. A material sheet is sandwiched and pressed while being heated to manufacture an uneven groove portion. In this case, there is a gap of the thickness of the material sheet between the upper mold and the lower mold, and the material sheet is exactly pressed by the upper and lower molds on both front and back surfaces. For example, the convex ribs of the mold of the concave-convex groove portion for forming the concave-convex multi-groove structure and the concave grooves of the lower mold come into contact with the material sheet, and the sheet is firmly pressed from above and below to be heated.

However, in such a method, even if the dimensional accuracy of the mold is increased and the thickness of the material sheet is made uniform, uneven contact between the sheet and the mold is unavoidable and the gap between the mold is filled. The elastomer flows to. Therefore, it is unavoidable that uneven residual strain occurs in the product after pressing.

Even if an attempt is made to extremely increase the accuracy of the thickness of the sheet and the accuracy of the mold in order to eliminate the residual strain, it is very difficult to make a material sheet with such accuracy, and the mold is expensive. The problem arises that

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for manufacturing a diaphragm having uniform and large flexibility.

[Means for Solving the Problems] In order to manufacture a diaphragm having flexibility with respect to stretching without forming strain, the inventors of the present invention should form the diaphragm with as little fixation as possible to obtain uniform flexibility. The present invention was completed based on this finding by discovering that a different diaphragm can be obtained.

That is, the present invention is a method for manufacturing a diaphragm in which an elastomer composite sheet is sandwiched between upper and lower molds and pressed,
A set of upper and lower molds having a convex rib portion and a concave groove portion on at least a part of the mold surface, wherein the metallic mold is provided at a position where a mating concave groove portion is fitted and opposed to the convex rib portion. The elastomer composite sheet is sandwiched in a mold, one side of the elastomer composite sheet is in contact with the convex rib portion, and the back surface is crosslinked by heating while being open to the space of the groove. The present invention provides a method for manufacturing a diaphragm having an uneven multi-groove structure.

A diaphragm having a concave-convex multi-groove structure according to the present invention has a concave-convex multi-groove structure on the front surface or a part of the diaphragm. The concave-convex multi-groove structure means at least a part of the diaphragm as shown in FIG. The cross section has a waveform 2. The shape of the diaphragm is not limited, and any shape such as a circular shape, a square shape, or the like can be used, and the shape of each concave and convex groove can be a circular or square annular shape or a simple straight or curved shape.

An example of the diaphragm having the uneven multi-groove structure of the present invention is
For example, as shown in FIG. 2, the central portion 3 and the peripheral portion 1 of one flat rubber sheet are flat, and a large number of concavo-convex grooves 2 are concentrically provided between the central portion 3 and the peripheral portion 1. Some are arranged side by side, and as shown in FIG. 3, the central plane portion 3 has a rectangular shape, and a rectangular concave-convex multi-groove structure 2 having a similar shape is provided around it.

2 and 3 show a diaphragm used as a metering film of a gas meter. When it is used as a metering film, a thin metal plate or a plastic plate is attached to the central flat surface, and it is held vertically to a gas meter as shown in FIG. 4 for use.

In this case, normally when the gas pressure is not applied, the diameter of this membrane is the same as the diameter between the upper and lower frames and is vertical. Metal thin plates 4 and 5 are attached to both surfaces of the central portion 3.

When a gas pressure is applied to this film, a large number of concave-convex groove structure portions 2 on the peripheral edge of the central flat surface portion 3 are sensitively stretched, so that the film can be moved laterally sensitively with a small gas pressure difference. The amount of gas can be accurately integrated by the diaphragm having such a groove and groove structure.

For example, when the diaphragm, which is the measuring film of FIG. 2, is manufactured by the manufacturing method of the present invention, it can be manufactured by pressing a material sheet using a mold having a cross section as shown in FIG.

This mold is composed of an upper mold 11 and a lower mold 12, and the upper mold 11 has a ring-shaped convex rib 13 and a plurality of parallel ring-shaped convex ribs 13 and a ring that do not come into contact with the rubber. There is a concave section 19.

This ring-shaped shape is usually selected according to the shape of the diaphragm, and depending on the shape of the diaphragm to be manufactured, the shape of the convex rib or the concave portion can be square or polygonal.

The lower mold 12 facing this has a circular flat surface portion 16 and a peripheral edge portion 22.
A ring-shaped convex rib 14 is provided at a position to be fitted into the flat surface portion and the concave portion 19 of the upper mold 11, and a ring-shaped concave portion 20 is provided at a position to receive the ring-shaped convex rib 13 of the upper mold 11.

The elastomer composite sheet used in the production method of the present invention can be obtained, for example, by rolling a rubber compounded with a commonly used rubber additive such as a cross-linking agent, a cross-linking aid, and a reinforcing agent, and pressing it onto fibers. it can.

As the elastomer used here, any one can be used as long as it is molded by a crosslinking reaction in a mold, for example, natural rubber, SBR, solution polymerization S
Crosslinking type elastomers such as BR, BR, NBR, CR, EPDM, IIR, shrimpchlorhydrin rubber and propylene oxide rubber can be used.

As the composite material sheet used in the present invention, a woven cloth or a non-woven cloth may be used, and a rubberized cloth having the above elastomer spread thereon and a sheet obtained by laminating the elastomer on a film may be used as the material.

When the material sheets are sandwiched and closed in the upper and lower molds in FIG. 5, the material sheets are pressed in contact with the flat surfaces of the upper and lower molds at the central circular flat surface portion and the peripheral portion.

However, although the ring-shaped convex ribs 13 and 14 are in contact with each other, the material sheets are not in contact with the recesses 19 and 20 on the back surface thereof.

Therefore, the material sheet between the peripheral edge portion and the central plane portion is not stretched but is stretched freely when the deep rib groove is deformed by the convex ribs, and the convex and concave portions have a uniform thickness in the vertical direction and the parallel direction. A multi-groove structure is obtained.

When the material sheet is fixed and heated by such a mold,
A cross-linking reaction proceeds to produce a diaphragm having an uneven multi-groove structure.

[Example] A 100-denier polyester 0.15 mm thick plain weave woven fabric was coated with epichlorohydrin rubber containing a crosslinking agent to give a thickness.
A 0.34 mm rubber sheet is cut into a diameter of 10 cm, put in a mold of 10 cm in diameter shown in Fig. 5, and the mold is closed, and the mold temperature is 160 ° C.
After pressing for 30 minutes, a diaphragm for a gas meter having an uneven multi-groove structure was manufactured.

As a result of measuring with a gas meter incorporating this diaphragm, it was a metering film with excellent flexibility that reacts sensitively as a reaction to gas pressure.

[Effects of the Invention] The diaphragm manufactured by the manufacturing method of the present invention is extremely flexible because a uniform concave-convex multi-groove structure can be obtained. For example, when this is used for a metering film of a gas meter,
Since it moves and moves sensitively to gas pressure, it is possible to measure an accurate volume.

Furthermore, the diaphragm of the present invention requires compressive strength,
Moreover, it can be used for a device that responds to a fluid having a slight pressure.

[Brief description of drawings]

FIG. 1 is a sectional view of a metering membrane for a gas meter, which is an example of a diaphragm having an uneven multi-groove structure manufactured by the manufacturing method of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is another metering film. FIG. 4 is a plan view of the diaphragm, FIG. 4 is an explanatory view of the operating state of the measuring membrane, and FIG. 5 is a cross-sectional view showing the structure of a mold used in the manufacturing method of the present invention. Reference numerals in the figure are 1; film peripheral portion, 2; uneven corrugated groove portion, 3; central flat surface portion, 4,5; film plate, 11; upper mold, 12; lower mold, 13, 14; ring-shaped convex Ribs, 15,16; flat parts, 17,18; mold closing surface, 1
9, 20; ring-shaped recessed portion, 21, 22; mold peripheral portion, A; central flat surface portion of measuring film rubber sheet, B; uneven multi-groove structure portion, C; membrane plate, D; film holding portion, E; weighing It is the volume.

Claims (2)

[Claims] 1. A method of manufacturing a diaphragm, which comprises sandwiching an elastomer composite sheet between upper and lower dies and pressing the dies, comprising a set of upper and lower dies having a convex rib portion and a concave groove portion on at least a part of the die surface. The elastomeric composite sheet is sandwiched by a mold provided at a position where a mating groove is fitted and opposed to the convex rib, and one side of the elastomeric composite sheet is in contact with the convex rib, and the back surface thereof is Is a method of manufacturing a diaphragm having an uneven multi-groove structure, characterized by heating and cross-linking while being opened to the opposed groove spaces. 2. The method of manufacturing a diaphragm according to claim 1, wherein the rubber sheet has a flat surface portion in the central portion and a large number of annular corrugated corrugated grooves are arranged in parallel with the peripheral edge portion.