JP3079268U - Leak prevention device for injection molding machine - Google Patents

Abstract

(57) Abstract: Provided is a leakage prevention device for an injection molding machine that prevents material leakage caused by wear caused by friction between a material injection shaft and a shaft hole. SOLUTION: A material is injected by opening and closing a hole of a second injection nozzle, a material stop end is provided on a second shaft, and the second shaft passes through a heat material passage plate 2, a material stop valve and a shaft fixing base. The rear end of the second shaft protrudes from the shaft fixing base and is connected to the piston of the mold fixing plate 6, and the stop end of the front end of the second shaft allows material injection and closing of the second injection nozzle. become. A first injection nozzle 82 is provided in front of the material stop valve 8 at the front end of the helical material transport pipe 7, and the flow cylinder provided in the material stop valve 8 and the tip of the first shaft are connected to the first injection nozzle 82.
, And the rear end of the first shaft is connected to a cylinder lever, so that the material can be injected and closed from the first injection nozzle 82.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a sealing device for a plastic injection molding machine.

[Prior art]

[0002] The shaft of a material stop valve installed on a thermal material passage plate in an injection molding machine such as a conventional plastic is all linear and annular hollow, and a sket (shown in FIG. 9) is provided at the subsequent stage. After being fitted, it is installed in the shaft fixing base. When the material stop valve and the shaft of the heat material passage plate are closed, there is excess pressure in the heat material passage plate, the raw material flows and fills the gasket, and the gasket expands, and the raw material flows into the shaft. From the space between the shaft and the shaft fixing base. Therefore, if the gasket is used for a long period of time, the constant expansion and contraction of the gasket not only fatigues the shaft, but also causes the center hole of the shaft fixing base to wear due to friction with the longitudinal movement of the shaft, causing material leakage. Become. In addition, this hollow gasket is a high technical product and therefore expensive.

Further, there is a valve system (shown in FIG. 10) designed by DME Company of the United States. This is because the contact surface between the shaft (A) and the center hole (A1) has been improved to a longer one and its use time has been extended. Occurs and the material leaks out (indicated by the arrow in FIG. 10). As shown in FIG. 11, the shaft of the material stop valve installed in the helical material transport pipe of still another injection molding machine has a sharp cone at its tip, and this sharp cone crayon is formed. The stop end of the shaft, such as a rod, is attached to the injection nozzle. However, since the excess pressure still remains in the raw material in the flow cylinder in the material stop valve, the raw material leaks from the gap at the screwed portion.

[0004] In addition, Japanese Patent Application Laid-Open No. Hei 7-223241 has two kinds of the same linear shafts B and shaft holes B1 as shown in FIG. High pressure is prevented. However, if the allowance due to the tolerance is too small, the operation of the shaft B may be interfered and jammed, and may not move. After a certain period of use, the friction between the shaft B and the shaft hole B1 causes abrasion, and the distance between the shaft and the shaft B1 increases, so that the material leaks and becomes unusable. And a fire may occur.

[0005]

[Problems to be solved by the invention]

 SUMMARY OF THE INVENTION It is an object of the present invention to provide a leakage preventing device for an injection molding machine which prevents material leakage caused by wear caused by friction between an injection shaft and a shaft hole.

[0006]

[Means for Solving the Problems]

 According to the present invention, the front end of the second shaft is capable of injecting the material by piercing or closing a second injection nozzle for injecting the material into the mold of the injection molding machine, and moving back and forth so that it can be completely closed. The second shaft is provided through the heat material passage plate, the material stop valve, and the shaft fixing base, and the rear end of the second shaft projects from the shaft fixing base to form the mold fixing plate. A stop end at the front end of the second shaft allows the injection and closing of the material of the second injection nozzle by being connected to the piston so as to be able to move back and forth.

In order to further supply the material to the thermal material passage plate, another first injection nozzle is provided at the front end of the spiral material transport pipe in front of the material stop valve, and is provided on the material stop valve. The front end of the first injection nozzle is screwed into the hole of the first injection nozzle, and the rear end of the first shaft is connected to the cylinder lever so that it can move back and forth. Injection and closure become possible.

[0008] The leak prevention device of the injection molding machine according to the present invention is capable of closing and injecting the material by being inserted into or separated from the hole of the injection nozzle at the material stopper end at the front end of the two shafts moving back and forth. There is no friction, so no matter how long the machine is used, no material will leak out.

[0009]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 4, a leak preventing device for an injection molding machine according to one embodiment of the present invention is provided with a heat material passage plate 2 on the rear side of a mold 1. A material stop valve 3 is fixed to the front side of the passage 20 with a screw. On the rear side of the material stop valve 3 corresponding to the flow passage 20, a shaft fixing base 4 is provided. The shaft fixing base 4 has a central hole 40. A localized portion 41 having a slightly larger diameter is formed. Further provided is a material stop valve 3, a second shaft 5 passing through the flow passage 20 and the shaft fixing base 4, and a stop end 50 at the front end of the second shaft 5 is provided at the center support plate 31 of the material stop valve 3. , The rear end of the second shaft 5 protrudes from the shaft fixing base 4, is connected to a piston 61 fixed to the mold fixing plate 6, and is moved back and forth by the piston 61. Then, the material stop end 50 of the second shaft 5 can be inserted and removed from the hole of the injection nozzle 32 of the material stop valve 3.

Next, reference is made to FIGS. Further, a helical material transport pipe 7 is provided, and a flow cylinder 81 and a first shaft 9 are installed in a material stop valve 8 connected to the helical material transport pipe 7. The rear end is connected to the cylinder lever 90 and is moved by the cylinder lever 90 so that the material stop end 91 at the front end of the first shaft 9 moves in and out of the first injection nozzle 82 to prevent leakage of the material.

A feature of the leakage preventing device of the injection nozzle is that a leakage preventing portion 51 having a slightly larger diameter than the outer portion is formed in the middle portion of the second shaft 5 as shown in FIGS. When the material stopping end 50 of the second shaft 5 injects the material away from the second injection nozzle 32 due to the mutual localization contact with the localization portion 41 of the shaft 4, the contact surface of the leak prevention portion 51 becomes the shaft fixing base. 4 to prevent the raw material from leaking out of the shaft fixing base 4.

The first shaft 9 has a material stopper end 91 which is gradually thicker at its rear end to form a leak stop 92 in the middle, and after the spiral material transport pipe 7 has delivered the material, the first shaft 9 When the material stop end 91 is fitted with the first injection nozzle 82, the high-pressure and high-temperature raw material received inside the flow tube 81 presses against the inner wall plane of the leak preventing portion 92, whereby the raw material is tightly fitted and closed, and the raw material is closed. Block.

[0013] The leak preventing portion 51 in the fluid closing type injection nozzle leak preventing device of the injection molding machine according to one embodiment of the present invention is a positioning portion 41 of the shaft fixing base 4 when the second injection nozzle 32 injects the material. In addition to being able to prevent the raw material from leaking out of the shaft fixing base 4 by being fitted, the material stop end 91 of the first shaft 9 is fitted with the first injection nozzle 82 after the spiral material transport pipe 7 has delivered the material. The high-pressure and high-temperature raw material received by the flow cylinder 81 presses against the inner wall plane of the leak preventing portion 92, thereby firmly fittingly closing and blocking the raw material. Therefore, there is no material leakage caused by the friction between the conventional shaft and the shaft hole.

[Brief description of the drawings]

FIG. 1 is a side view showing a leakage prevention device of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a hot material injection plate and a mold fixing plate of the leakage prevention device of the injection molding machine according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a material stop valve and a shaft in a shaft fixing base of the leak preventing device of the injection molding machine according to one embodiment of the present invention;

FIG. 4 is a sectional view showing a closed side of a shaft in a shaft fixing base and a material stop valve of a leak preventer of an injection molding machine according to an embodiment of the present invention;

FIG. 5 is a side cross-sectional view of a shaft in a material stop valve of the nozzle leak preventing device of the injection molding machine according to one embodiment of the present invention;

FIG. 6 is a side view of the shaft in the material stop valve of the leak preventer of the injection molding machine according to one embodiment of the present invention;

FIG. 7 is a side sectional view of a conventional shaft and a hollow annular gasket.

FIG. 8 is a side sectional view of a conventional valve system.

FIG. 9 is a side view of a conventional shaft.

FIG. 10 is a side sectional view of a conventional shaft and a correlated portion thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold 2 Heat material passage plate 3 Material stop valve 4 Shaft fixing base 5 Second shaft 6 Mold fixing plate 7 Spiral material transport pipe 8 Material stop valve 9 First shaft 20 Flow passage 31 Support plate 32 Second injection nozzle 40 Center Hole 41 Orientation 50 Stop end 51 Leak end 61 Piston 81 Flow cylinder 82 First injection nozzle 91 Stop end 92 Leak stop 90 Cylinder lever

Claims (1)

[Utility model registration claims] 1. A heat material passage plate provided at a rear side of a mold of an injection molding machine, a first material stop valve fixed to a front side of a flow passage of the heat material passage plate with a screw, A shaft fixing base provided on the rear side of the first material stop valve corresponding to the passage, a central hole provided on the shaft fixing base, and a diameter provided on the front side of the central hole is outside. A second shaft provided through the first material stop valve, the flow passage and the shaft fixing base, and a first material formed at a front end of the second shaft. A material stop end supported by a central support plate provided in the stop valve, a rear end of the second shaft projecting from the shaft fixing base, and connected together with the rear end of the second shaft. Mold fixed to move back and forth A plate piston, a second injection nozzle in which the material stop end of the second shaft fits and separates, a spiral material transport tube installed after the shaft fixing base, and a spiral material transport tube. A second material stop valve installed on the front side, a flow cylinder and a first shaft installed inside the second material stop valve, a first injection nozzle screwed with the first shaft, and the first shaft A cylinder lever connected to a rear end, wherein a middle portion of the second shaft forms a leak-proof portion whose diameter is larger than an outer portion, and is in contact with the positioning portion of the shaft fixing base. When the material stop end of the second shaft moves away from the second injection nozzle and injects the material, the contact surface of the leak stop fits into the localization portion and the raw material is transferred to the second shaft. To prevent the spiral material transport pipe from leaking out from the stereotactic portion. The material stop end of the first shaft fits into the first injection nozzle and pushes the high-temperature and high-pressure raw material received by the inside of the flow cylinder to the inner flat surface of the leak preventing portion, whereby the raw material A leak prevention device for an injection molding machine, which strongly closes and prevents injection.