JPS6024672Y2 - Synthetic resin booster shell - Google Patents

Description

[Detailed description of the invention] The present invention is mainly used for a synthetic resin booster shell of a negative pressure booster that boosts the brake mask cylinder of an automobile using negative pressure, and in particular for a negative pressure hose having an annular anti-slip ridge on its outer periphery. This relates to a device in which a connecting pipe is molded and protruded from the end face of the booster shell.

Fig. 3 shows a part of a conventional booster shell of this type and its molding die. The anti-slip protrusion 06a is simply raised.

Because of this protrusion 06a, when molding the booster shell 01, the outer surface of the booster shell 01 is formed by a pair of upper and lower outer molds 010a and 010b that are opened and closed at a dividing surface passing through the axis of the connecting pipe 06, and the inner surface of the booster shell 01 is The inner surface is formed by molds 011, but the directions of movement of these molds are all different as shown by the arrows.

Since three movable molds, all moving in different directions, are required, the molding equipment becomes complicated and large, and equipment costs increase.
As a result, the cost of the product is high.

The present invention has been proposed in view of the above, and an object of the present invention is to provide the booster shell, which can be molded using a molding die with a simple structure without dividing the outer mold, and which can contribute to cost reduction.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a negative pressure booster for operating a brake mask cylinder M of an automobile, and its booster shell 1.
is a pair of synthetic resin fronts.

The open ends of the rear bowl-shaped bodies 1a, lb are connected by engagement between an annular locking pawl 2 and a locking groove 3, and the outer circumference of the diaphragm 5 of the booster piston 4 is clamped at the joint. .

A negative pressure hose connection pipe 6 is integrally molded and protruded on the front surface of the front bowl-shaped body 1a, and an annular anti-slip ridge 6 is provided on the outer periphery of its tip.
a is raised.

A negative pressure hose 7 made of rubber or the like that is connected to a negative pressure source (not shown), such as the intake manifold of an automobile engine, is fitted onto the outer periphery of the connecting pipe 6, and the portion of the hose 7 that passes through the anti-slip protrusion 6a is fitted. self-contracting hose band 8
The hose 7 is thereby reliably connected to the connecting pipe 6.

The negative pressure hose 7 is equipped with a check valve 9, which prevents the negative pressure introduced into the booster shell 1 through the negative pressure hose 7 from flowing back toward the negative pressure source when the negative pressure of the negative pressure source decreases. This is to prevent

The connecting pipe 6 has a range A from its tip to the anti-slip protrusion 6a.
In this case, the inner diameter is enlarged and the wall thickness is reduced.
This point is a feature of the present invention.

The mold for forming the front bowl-shaped body 1a having the connecting pipe 6 is placed in a second mold.
As shown in the figure.

That is, the mold has an outer mold 10 that forms the outer peripheral surface of the connecting pipe 6 and the bowl-shaped body 1a, an inner mold 11 that forms the inner peripheral surface of the bowl-shaped body 1a, and the inner mold 11 cooperates with each other. The pin core 12 forms the inner circumferential surface of the connecting tube 6, and both molds 10 and 11 open and close in the axial direction of the connecting tube 6 as shown by the arrows. It is designed to penetrate and move in the same direction as it.

Therefore, when molding, both molds 10 and 11 are used as shown in the same figure.
At the same time, the pin core 12 is brought into contact with the inner mold 11, and the product cavity formed by the pin core 12 is filled with molten synthetic resin, whereby a predetermined product is molded.

When releasing the mold, first the pin core 12 is retreated and pulled out from the connecting tube 6, and then both molds 10 and 11 are opened.

At this time, the protrusion 6a on the outer periphery of the connecting tube 6 is biting into the outer mold 10, but as described above, the protrusion 6a extends from the tip of the connecting tube 6.
Since the wall thickness is reduced within the range of , the protrusion 6a can be elastically deformed inward and easily detached from the outer mold 10.

As described above, according to the present invention, the annular anti-slip ridge 6 is provided on the outer periphery.
In a synthetic resin booster shell 1 in which a negative pressure hose connection pipe 6 having a diameter of 1.a is molded and protruded from the end face, the inner diameter of the connection pipe 6 is enlarged in a range A from the tip of the connection pipe 6 to the protrusion 6a. Since the wall thickness has been increased, the wall thickness of the connecting tube 6 is relatively thin even at the protrusion 6a, and it can be easily elastically deformed during mold release.As a result, there is no need to divide the outer mold, so the molding The mold structure is significantly simplified and costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of a negative pressure booster equipped with the booster shell of the present invention, and Fig. 2 is a vertical sectional view of a portion of the booster shell, that is, the front bowl-shaped body and its molding die. , FIG. 3 is a vertical sectional view of a part of a conventional booster shell and a mold for forming the same. A...Range, 1...Booster shell,
6... Negative pressure hose connection pipe, 6a... Anti-slip protrusion.

Claims (1)

[Scope of utility model registration request] In a synthetic resin booster shell 1 in which a negative pressure hose connection pipe 6 having an annular anti-slip protrusion 6a on the outer periphery is molded and protruded from the end face, an area A from the tip of the connection pipe 6 to the protrusion 6a
A synthetic resin booster shell characterized in that the inner diameter of the connecting pipe 6 is increased and the wall thickness thereof is decreased.