JPH0228033Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to a synthetic resin injection valve.

<Prior Art> Conventionally, when coating a rigid body such as a sleeper with a synthetic resin, an injection valve as shown in FIG. 1 has been used.

This injection valve is attached to the mold 1 via a female threaded member 3 attached to a connection port 2 opened in the synthetic resin injection mold 1, and a casing 4 whose tip end is screwed into the female threaded member 3 A synthetic resin passage 6 is provided in the casing 4, which opens into the formwork 1 and is opened and closed by a valve body 5. In such a synthetic resin injection valve, a certain distance d is required between the opening of the synthetic resin passage 6 into the formwork 1, that is, the connection port 2, and the valve body 5.
After the synthetic resin is injected and cured, a rod-shaped body 7 of synthetic resin is formed within this distance d as shown in FIG. This rod-shaped body 7 is formed integrally with the synthetic resin layer 8 formed in the formwork 1, and since the rigid body is demolded in a direction perpendicular to the rod-shaped body 7, the rod-shaped body 7 has a female thread when demolded. It hits the inner surface of the member 3 and is peeled off from the synthetic resin layer 8. Then, a recess 9 is formed in the synthetic resin layer 8, and this recess 9 becomes a defect in the synthetic resin layer 8.

Therefore, injection valves that do not produce rod-shaped bodies 7 have been developed.

As shown in FIG. 3, this injection valve has a generally Y-shaped tubular casing 10 whose tip end is screwed onto the female threaded member 3, and this casing 10 has a main pipe that is linearly continuous with the female threaded member 3. 11, and a branch pipe 12 branched from near the tip. A synthetic resin passage 11A and a guide passage 11B are formed in the main pipe 11 from the distal end side, and a branch passage 12A communicating with the passage 11A is formed in the branch pipe 12. In such a casing 10, a synthetic resin injection device M is connected to the branch pipe 12, and a piston 14 having a stopper 13 is slidably housed in the main pipe 11.

Here, the length of the piston 14 is the length of the casing 1
0, and the tip 14A is the same as the length of the passage 11.
When introduced into A, the tip surface of the tip portion 14A is flush with the inner surface of the formwork 1 and the tip surface of the casing 10.

In such a configuration, the synthetic resin is injected into the formwork 1 through the passages 12A and 11A in the state shown in FIG. By introducing the resin into the passages 11A and 12A, it is possible to prevent the synthetic resin from flowing back into the passages 11A and 12A, and to remove the synthetic resin remaining in the passages 11A into the formwork 1. This prevents the formation of the rod-shaped body 7 and also prevents the synthetic resin from flowing into the passages 11A and 12A. 2, a smooth synthetic resin surface is obtained.

In the injection valve having such a configuration, the piston 1
4 is forced from the base end, but since the synthetic resin is injected into the mold 1 at a predetermined injection pressure, the pushing force of the piston 14 needs to be large enough to overcome this pressure. Although various mechanisms such as a fluid pressure cylinder are conceivable for carrying out such pushing, a mechanism that is simple and can easily carry out pushing is desired.

<Purpose of the invention> This invention was devised in view of the above circumstances, and its purpose is to provide a synthetic resin injection valve with a relatively simple structure and a mechanism that allows easy pumping. It is in.

<Structure of the invention> The synthetic resin injection valve according to the invention has an engaging protrusion protruding from the outer surface of the casing, and a pushing member having the engaging protrusion at the base end of the piston, and the pushing member is moved in the direction of the mold. A guide groove for guiding is formed in the casing, an engaging protrusion of the casing and an engaging protrusion of the pushing member are connected by a spring member, and the piston is pushed by the biasing force of the spring member.

<Example> Hereinafter, this invention will be described based on an illustrative example. This embodiment is an example of an injection valve having a structure similar to that shown in FIG. 3, and parts that are the same or corresponding to those in FIG. 3 are given the same reference numerals, and a description thereof will be omitted.

As shown in FIGS. 4 to 7, the casing 10 is divided into two parts and the straight pipe 11 is made into a flat shape so that it can be attached and detached using bolts 15. Further, the length of the straight pipe 11 is longer than the length of the piston 14 by the piston stroke l.

Engagement protrusions 16, 16 are protrudingly provided on the flat outer surface of the straight pipe 11 at approximately the center in the longitudinal direction, and an engagement protrusion 17 is provided on the base end of the piston 14.
A rod-shaped pushing member 17 having A is provided in abutting state.

Furthermore, guide grooves 18, 18 are bored in the base end of the straight pipe 11 over a distance l from the base end surface toward the formwork, and the pushing member 17 can be moved in the longitudinal direction by the guide grooves. will be guided to.

Further, the engagement protrusion 16 and the engagement protrusion 17A are connected by a spring member 19, and the urging force of the spring member 19 causes the pushing member 17, that is, the piston 14
is pushed toward the formwork.

Further, since the pushing member 17 is always urged by the spring member 19, the straight pipe 11 is moved as shown in FIG. 7 to prevent the piston 14 from moving during injection.
A locking groove 20 is formed in the proximal end surface of. This locking groove 20 is arranged at an angle shifted from the guide groove 18, and can be locked to the straight pipe 11 by simply rotating the pushing member 17 slightly.

In this state, the synthetic resin flows through the passages 12A, 1
1A into the formwork 1, and at the end of the injection, if the pushing member 17 is released from the locking groove 20,
The spring member 19 moves the piston 14 by a distance l so that the tip 14A can be easily introduced into the passage 11A.

Furthermore, since the casing 10 is divided into two parts, there is an advantage that the inside of the casing can be easily cleaned after the injection operation is completed.

Next, a mechanism for attaching such a casing 10 to the formwork 1 will be explained.

As shown in FIG. 4, the tip of the casing 10 is formed into a cylindrical shape, and as shown in FIG.
1 is fixed by welding or the like, and a positioning protrusion 2 is positioned at a predetermined position at the tip of the casing 10.
2 is provided in a protruding manner, and the positioning protrusion 22 and the female screw member 21 are fastened together by a nut member 23 that is loosely fitted to the tip of the casing 10.

The male threaded member 21 has a fitting hole 21A into which the tip of the casing 10 is fitted, and is fixed so that its mold side end surface 21S is flush with the inner surface 1S of the mold.

The positioning protrusion 22 contacts the male threaded member 21 and connects the inner surface 1S of the formwork and the tip surface 10 of the casing 10.
It is fixed in such a position that it is flush with S.
This protrusion 22 may be a continuous ring shape in the circumferential direction or may be an intermittent protrusion.

The nut member 23 has a ring shape with a cross-sectional shape, and has a female thread formed on the inner surface of the distal end portion 23A to be screwed into the male thread of the male threaded member 21, and a proximal end portion 23B abuts against the positioning protrusion 22.

In such a configuration, when installing,
By loosely fitting the nut member 23 into the tip of the casing 10 in advance and fitting the tip of the casing 10 into the male threaded member 21, positioning can be easily achieved and the tip surface 10S is flush with the inner surface 1S of the formwork. become. Next, the nut member 23 is tightened to complete the installation. When attaching or removing the nut member 23 without rotating the casing 10,
This can be easily done by simply rotating the .

Although this idea can be applied to any synthetic resin injection, significant effects can be obtained if applied to the synthetic resin coating of elastic direct-linked sleepers.

<Effects of the invention> This invention consists of the above structure, so
With a relatively simple configuration, the piston can be easily pushed and the injection valve can be made at low cost. Furthermore, this makes it possible to easily obtain a smooth synthetic resin surface at the connection port of the formwork. Furthermore, by dividing the casing into two, the inside of the casing can be easily cleaned after the injection operation is completed.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional injection valve, FIG. 2 is a vertical sectional view showing a rod-shaped body produced by this conventional example, and FIG. 3 is a plan sectional view showing another conventional injection valve.
4 and 5 are a plan view and a front view showing the injection valve according to this invention in cross section, and FIGS. 6 and 7 are a sectional view taken along the line - and a view taken along the - line in FIG. ,
FIG. 8 is an enlarged sectional view of the formwork attachment part. 1...Synthetic resin injection formwork, 2...Connection port, 3...
...Femally threaded member, 4...Casing, 5...Valve body,
6... Synthetic resin passage, 7... Rod-shaped body, 8... Synthetic resin layer, 9... Recess, 10... Casing, 11
...Main pipe, 11A...Synthetic resin passage, 11B...
Guide passage, 12... Branch pipe, 12A... Branch passage, 13... Stopper, 14... Piston, 14
A... Tip part, 15... Bolt, 16... Engaging protrusion, 17... Pushing member, 17A... Engaging protrusion, 1
8... Guide groove, 19... Spring member, 20... Locking groove, 21... Male thread member, 21A... Fitting hole, 2
2... Positioning protrusion, 23... Nut member, 23
A...Distal end, 23B... Base end.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A casing whose tip is connected to the connection port of a synthetic resin injection mold, and a casing which is movable within the casing and which uses the synthetic resin remaining in the casing after the synthetic resin is injected into the mold. This is a synthetic resin injection valve equipped with a piston that can be removed inside the casing, in which an engaging protrusion is provided protruding from the outer surface of the casing, and a pushing member having an engaging protrusion is provided at the base end of the piston, and this pushing member is inserted into the mold. 1. A synthetic resin injection valve characterized in that a guide groove for guiding the direction is formed in the casing, and an engagement protrusion of the casing and an engagement protrusion of the pushing member are connected by a spring member. (2) The synthetic resin injection valve according to claim 1 of the utility model registration, characterized in that the casing is divided into two parts.