JPH08118422A - Plunger of forced feeding device of green material to injection machine - Google Patents

Abstract

PURPOSE: To realize no development of the extruding troubles such as air leakage and the like of a green material and, easy pulling-out of a plunger by a method wherein an opened rear cavity is provided so as to join a mushroom valve, which abuts against the valve seat of a front cavity, to the front end of a shaft passed movably through the through hole of a wall. CONSTITUTION: The plunger 40 of the forced feeding device of a green material to an injection machine is movably fitted into a pot 21 so as to extrude and feed the green material 90 through a green material feed opening 23 to the injection machine. In this case, a tubular front cavity 43, in which an inverted conical valve seat 48 is provided. Further, a communicating hole 44, which communicates with the rear part of the front cavity 43 and is opened to the front side face of a rear part 42. In addition, at the rear part 42, a tubular rear cavity 45, which is opened to a rear surface coaxially to the front cavity 43 through a wall 47. Furthermore, to the front end of a shaft 51 passed movably through a through hole 46 made in the wall 47, an inverted conical mushroom valve 52, which is abutted against the valve seat 48 of the front cavity 43, is joined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber raw material forced supply device for an injection machine.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 1 and 2, an apparatus for forcibly supplying raw material to an injection machine has a cylindrical pot 21 having a raw material supply port 23 for the injection machine 10. Plunger 22 is fitted to the pot 21, and the raw material 90 is loaded in the pot 21, the plunger 22 is pushed by the cylinder 30 to push the raw material 90 into the injection machine 10 through the raw material supply port 23. I am supplying it.

However, the plunger 22 of the above-mentioned conventional raw material forced-feeding device for an injection machine has a small gap between the inner wall of the pot 21 and the plunger 22 and is sealed with the raw material 90, as shown in FIG. When pulling out,
There is a problem that the inside of the pot 21 is depressurized Q and a difference is generated between it and the external pressure P, which makes it difficult for the plunger 22 to come off. Therefore, there is also a problem that the behavior of the raw material 90 remaining in the pot 21 is unstable at the time of drawing, and it is difficult to specify.

[0004]

The problem to be solved is that the plunger 22 of the conventional raw material forced-feeding device for the conventional injection machine described above has the following problems.
The inside of the pot 21 is decompressed and a difference is generated between the pot 21 and the outside pressure, making it difficult for the plunger 22 to come off. Therefore, the behavior of the raw material 90 remaining in the pot 21 is unstable and difficult to identify. .

[0005]

According to the first aspect of the present invention, the raw material 90 is fitted into the pot 21 such that the raw material 90 can move forward and backward.
It is a plunger of a raw material forced supply device for an injection machine that is extruded into and supplied into an injection machine 10 via a cylindrical front cavity 43 provided with an inverted conical valve seat 48 at its front portion, and the front thereof is provided. A communication hole 44 that communicates with the rear portion of the cavity 43 and that opens to the front side surface of the rear tail portion 42 is provided, and the rear rear portion 42 has a cylindrical rear cavity that opens to the rear surface with a wall 47 coaxially with the front cavity 43. 45 is provided, and an inverted conical mushroom valve 52 that is brought into contact with the valve seat 48 of the front cavity 43 is coupled to the front end of a shaft 51 that is passed through a through hole 46 formed in the wall 47 so as to be able to move forward and backward. is there.

According to a second aspect of the present invention, in addition to the structure of the first aspect of the invention, a coil spring 53 is sequentially provided at the rear portion of the shaft 51 in the rear cavity 45, and an annular spring seat 54 for pressing the rear surface of the coil spring 53. The nut 56 for pressing the spring seat 54 is screwed into the threaded rod portion 55 formed in the rear portion of the shaft 51.

[0007]

As shown in FIG. 4, the raw material 90 is inserted into the pot 21, the plunger 40 is moved forward, and the raw material 90 is pushed by the front surface thereof, and is forced into the injection machine 10 through the raw material supply port 23. Supply. At that time, the pressure inside the pot 21 is increased, and the mushroom valve 52 is pressed against the forehead 41 by the pressure, retracts with the shaft 51 with respect to the forehead 41, and contacts the valve seat 48 of the front cavity 43. Therefore, air leaks and other raw materials 90
Does not cause any trouble in extruding.

On the contrary, when the plunger 40 is retracted and is to be pulled out, the pressure inside the pot 21 is reduced and the front cavity 4
3. Through the communication hole 44, the mushroom valve 52 is pushed forward against the backward force of the coil spring 53 by the external pressure P exerted on the back surface of the mushroom valve 52, whereby the valve seat 48 and the mushroom valve 5 are pushed.
Since a gap is generated between the plunger 40 and the external pressure P and the external pressure P is introduced into the pot 21, the pressure inside the pot 21 becomes the same as the external pressure P, so that the plunger 40 can be easily pulled out. Moreover, the remaining raw material 90 can be reliably positioned at the bottom of the pot 21.

[0009]

EXAMPLE An example will be described. 10 is a raw material 90.
Injection machine that extrudes and manufactures molded products,
Reference numeral 11 is a screw, 12 is a motor for rotating the screw 11, 20 is a raw material forced supply device for extruding and supplying the raw material 90 into the injection machine 10.
It is provided with a pot 21 having a raw material supply port 23 for the injection machine 10, a plunger 40 which is fitted in the pot 21 so as to be able to move forward and backward, and which pushes the raw material 90, and a cylinder 30 which reciprocates the plunger 40. 41 is the forehead,
42 is a rear tail portion whose diameter is reduced stepwise as compared with the diameter of the front head portion 41, 43 is a cylindrical shape which is opened in the front surface of the front head portion 41 and whose rear end reaches the front portion of the rear tail portion 42 It is a front cavity, and its opening, that is, the front portion is expanded in an inverted conical shape, and the valve seat 4
8 is formed. 44 is a communication hole that communicates with the rear portion of the front cavity 43 and is provided so as to open on the side surface of the rear tail portion 42, and 45 is opened in the rear tail portion 42 by separating a wall 47 coaxially with the front cavity 43. A cylindrical rear cavity provided so that 51 is a shaft through which the through hole 46 formed in the wall 47 can be advanced and retracted, 52 is connected to the front end of the shaft 51, and is expanded into an inverted conical shape of the front cavity 43. An inverted conical fungus valve to be brought into contact with the valve seat 48, 53 and 54 are coil springs sequentially fitted to the rear portions of the shafts 51 protruding into the rear cavity 45, and an annular spring seat for pressing the rear surface of the coil springs 53. 5
Reference numeral 6 denotes a nut screwed into a threaded portion 55 formed on the rear portion of the shaft 51 to press the coil spring 53 via a spring seat 54.

[0010]

Since the present invention is configured as described above,
The plunger 22 can be pulled out significantly easier than the conventional one.

[Brief description of drawings]

FIG. 1 is a sectional view showing a raw material forced supply device for an injection machine.

FIG. 2 is a sectional view showing a conventional example.

FIG. 3 is a sectional view showing a main part of an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state when pushing a raw material according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state when the plunger of the embodiment of the present invention is pulled out.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 10 Injection machine 11 Screw 12 Motor 20 Raw material forced supply device 21 Pot 22 Plunger 23 Raw material supply port 30 Cylinder 40 Plunger 41 Front head 42 Rear tail 43 Front cavity 44 Communication hole 45 Rear cavity 46 Through hole 47 Wall 48 Valve seat 51 Shaft 52 Bush valve 53 Coil spring 54 Spring seat 55 Screw part 56 Nut 90 Raw material P External pressure Q Decompression

Claims (2)

[Claims] 1. A raw material for an injection machine which is fitted into a pot (21) so as to be able to move forward and backward, and which is fed by pushing a raw material (90) into an injection machine (10) through a raw material supply port (23). In the plunger of the forced material feeder,
A communication hole that is provided in the front portion with a cylindrical front cavity (43) having an inverted conical valve seat (48), communicates with the rear portion of the front cavity (43), and opens to the front side surface of the rear tail portion (42). (44)
And a cylindrical rear cavity (45) opening to the rear surface is provided in the rear tail portion (42) coaxially with the front cavity (43) with a wall (47) separated, and a penetration opened in the wall (47). Hole (4
6) An injection machine in which a conical mushroom valve (52) having an inverted conical shape that is brought into contact with a valve seat (48) of a front cavity (43) is connected to a front end of a shaft (51) that is capable of advancing and retracting. Plunger for raw material forced supply device. 2. A raw material for an injection machine which is fitted into a pot (21) so as to be able to move forward and backward, and which is made by pushing a raw material (90) through a raw material supply port (23) into an injection machine (10) and supplying it. In the plunger of the forced material feeder,
A communication hole that is provided in the front portion with a cylindrical front cavity (43) having an inverted conical valve seat (48), communicates with the rear portion of the front cavity (43), and opens to the front side surface of the rear tail portion (42). (44)
And a cylindrical rear cavity (45) opening to the rear surface is provided in the rear tail portion (42) coaxially with the front cavity (43) with a wall (47) separated, and a penetration opened in the wall (47). Hole (4
An inverted conical mushroom valve (52) that abuts against the valve seat (48) of the front cavity (43) is connected to the front end of the shaft (51) passed through the rear cavity (45). A coil spring (53) is sequentially attached to the rear portion of the shaft (51), and an annular spring seat (5) for pressing the rear surface of the coil spring (53).
4) is fitted, and a nut (56) for pressing the spring seat (54) is screwed into a threaded rod portion (55) formed in the rear portion of the shaft (51). Plunger.