JPH0627876Y2 - Diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a diaphragm having a base cloth embedded therein, and more particularly to a structure of a flange portion for mounting and fixing.

(Prior Art) Conventionally, a diaphragm made of a rubber-like elastic body in which a reinforcing base cloth is embedded is known. A flange portion for attaching the diaphragm is projected on the outer peripheral edge of the diaphragm, and an annular protrusion (hereinafter referred to as a thread bead) is provided on the flange portion in order to improve the sealing property when the diaphragm is attached. ing.

FIG. 5 shows a sectional view of such a flange portion on the outer periphery of the diaphragm. In the figure, the base fabric 101 is embedded up to the inside of the flange portion 102, and the flange portion 1
On the surface of 02, one thread bead 103 is provided. Such a diaphragm has been integrally formed by placing a base cloth on a cloth such as rubber and vulcanizing it by a compression molding machine or the like.

(Problems to be solved by the invention) However, in such a diaphragm, the base fabric 101 may be exposed on the surface of the thread bead 103 during molding. In this case, for example, as shown in FIG. 6, when the flange portion 102 is sandwiched between the upper case 105 and the lower case 106 for sealing, the base cloth 101 is poor in elasticity and is not elastic. However, air and the like pass through between the base cloth 101 exposed on the surface of the bead 103 and the upper case 105 to cause airtight leakage.

As shown in FIG. 7, the problem of the exposure of the base cloth 101 is that the base cloth 1 is not formed in the cavity C of the mold 108.
The upper mold 108a is formed by the rubber material 107 in which 01 is fluidized.
It is considered that the reason is that the base cloth 101 is pressed against and the base cloth 101 comes into close contact with the wall surface of the upper mold 108a, and the rubber cloth 107 does not rotate on the base cloth surface.

In particular, the wall surface of the upper mold corresponding to the bead 103 is the groove 108b.
When the base cloth 101 has a shape and is in close contact, the rubber cloth 107
Is considered difficult to enter.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The purpose of the present invention is to prevent the base cloth from being exposed on the surface of the protrusion and to improve the sealing property at the time of mounting. To provide.

(Means for Solving the Problem) In order to achieve the above object, in the present invention, in a diaphragm containing a base cloth in which a flange portion is provided with an annular protrusion, at least two protrusions are provided. The base cloth is embedded in the recess between the protrusions.

(Operation) In the diaphragm of the present invention, the base cloth is pressed by the protrusions of the molding die corresponding to the recesses between the protrusions and deeply embedded during molding, so that the base cloth is not exposed on the surface of the protrusions. .

(Example) Below, this invention is demonstrated according to the example of illustration. First
FIG. 1 is a sectional view of a flange portion on the outer periphery of a diaphragm according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a diaphragm made of a rubber-like elastic body containing a base cloth, which is composed of a thin-film diaphragm main body 20 and a flange portion 3 which integrally projects to the outer periphery of the diaphragm main body 20. The base cloth 2 is embedded over the entire surface from the diaphragm main body 20 to the flange portion 3 for reinforcement.

The flange portion 3 projects over the entire outer circumference of the diaphragm 1 and is thicker than the diaphragm body 20 and has a D-shaped cross section protruding in an arc shape on one side in the thickness direction, and one surface side thereof is the diaphragm body 20. The diaphragm main body 2 is on the same plane (hereinafter referred to as the front surface 1A) and has the other side (hereinafter referred to as the back surface 1B) protruding in an arc shape.
A step is formed on the back surface of 0 by an amount corresponding to the thickness.

The base cloth 2 is embedded in the surface of the diaphragm 1 in a biased manner, and the surface of the base cloth 2 is covered with a thin rubber material.

On the other hand, on the surface of the flange portion 3, two thread beads 4 and 4 are provided as annular protrusions extending over the entire circumference thereof. The thread beads 4 are provided in a concentric circle shape, and each thread bead 4 projects in a substantially mountain-shaped cross section.

Further, an annularly extending recess 5 is provided between the two thread beads 4 and 4. The cross-sectional shape of this recess 5 is
It is substantially U-shaped and is continuously formed on the slopes of the thread beads 4 and 4 facing each other. And the depth of the recess 5 is
The diaphragm body 20 is dug deeper than a plane extending from the surface thereof, and is about half the thickness of the diaphragm body 20.

On the other hand, the base cloth 3 extending in a substantially flat shape along the surface of the diaphragm main body 20 undulates in the flange portion 3 in a gentle arc shape so as to bypass the recess portion 5 by the depth of the recess portion 5 dug deeply. It is deeply embedded in the flange portion 3 in a closed state.

Next, a method of forming the diaphragm 1 will be described with reference to FIG.

First, between the upper mold 6 and the lower mold 7, the molding material 8 such as rubber material and the base cloth 2 are placed on top of the molding material 8. The upper mold 6 has two recessed grooves 9 for forming two thread beads,
An annular protrusion 10 is provided between the two grooves 9 (see FIG. 2 (a)).

Then, the mold is clamped and the molding material is heated and pressurized to vulcanize and form the diaphragm 1. At this time, the base cloth 2 is pressed down by the protrusions 10 of the upper mold 6 and deeply embedded in the molding material 8 (see FIG. 2 (b)), while the rubber material is filled in the concave groove 9 of the upper mold 6. The yarn beads 4 and 4 are filled and molded. Therefore, the base cloth 2 is not exposed on the surface of the thread bead 4.

FIG. 3 is a cross-sectional view of the device to which the diaphragm 1 is attached. In the figure, the outer peripheral flange portion 3 of the diaphragm 1 is sandwiched between the joint portion 13 of the upper case 11 and the lower case 12, and is fixedly attached. The space surrounded by the upper case 11 and the lower case 12 is divided into two chambers by the diaphragm 1, and the air in each case is sealed. In this device 14, in particular, when airtight leakage occurs in the joint portion 13 between the upper case 11 and the lower case 12, the air inside the upper case 11 escapes to the outside, so the flange portion 3 of the diaphragm 1 and the upper case 11 are discharged.
The sealability at the contact surface with is important.

FIG. 4 is a sectional view showing the flange portion 3 of the diaphragm 1 in the device 14. In the figure, the base cloth 2 is not exposed at the contact portion of the two thread beads 4 provided on the flange portion 3 of the diaphragm 1 with the upper case 11.
Since the molding material 8 having rubber-like elasticity occupies the thread bead 4, the thread bead 4 is airtightly adhered to the contact surface with the upper case 11, and good sealing performance is obtained. Further, since two such thread beads 4 are provided, the air in the upper case 11 is 2
Since the sealing is performed in stages, the sealing property can be greatly improved.

Although two thread beads are provided in this embodiment, the invention is not limited to this. For example, if three thread beads are provided and two recesses between thread beads are provided, the sealing property is further improved. be able to.

(Effects of the Invention) The present invention has the above-described configuration and operation, and since the base cloth is embedded via the recess between the protrusions,
It is possible to prevent the base cloth from being exposed on the surface of the protrusion as in the conventional case, and it is possible to improve the sealing property of the diaphragm mounting portion.

[Brief description of drawings]

FIG. 1 is a sectional view of a flange portion of a diaphragm of an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are explanatory views showing a method of forming the diaphragm of the embodiment, and FIG. 3 is the same embodiment. 4 is a cross-sectional view of a device having a diaphragm attached thereto, FIG. 4 is a cross-sectional view showing a flange portion of the diaphragm in the same device, FIG. 5 is a cross-sectional view of a flange portion of a conventional diaphragm, and FIG. 6 is a flange portion of the conventional example. Sectional view showing the attachment state of the
The figure is a schematic cross-sectional view showing an example of a method for forming the diaphragm of FIG. Explanation of reference numerals 1 ... Diaphragm, 2 ... Base cloth 3 ... Flange portion, 4 ... Thread bead (projection portion) 5 ... Recessed portion

Claims (1)

[Scope of utility model registration request] 1. A diaphragm containing a base cloth, wherein a flange portion is provided with an annular projection. At least two projections are provided, and the base cloth is embedded in a recess between the projections. A diaphragm characterized by being made.