JP3344809B2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for alternately switching a plurality of extruding rods with a time difference.

[0002]

2. Description of the Related Art For example, as an apparatus of this kind, the applicant has disclosed Japanese Patent Publication No. 1-5361.
No. 6 and Japanese Patent Publication No. 2-46144.

However, as means for alternately moving a moving body provided with each of the pushing rods with a time lag, the small-diameter shaft rod of the coaxial movable rod passes through the passage hole of one of the moving bodies and the other moves. Move the moving object of
In this configuration, the large diameter rod pushes the periphery of the passage hole to move only one moving body.

In the latter invention, a shutter for closing a passage hole of one of the moving bodies is configured to be openable and closable,
By closing the shutter, the shutter of the movable rod is pushed to move one moving body, and by opening the shutter, the movable rod penetrates the passage hole and moves only the other moving body.

In any case, it is very troublesome and complicated in structure to construct and control the coaxial movable rod, and to provide a shutter on one of the moving bodies, the production cost is high, and the extremely expensive injection rod is required. There is a problem that it becomes a molding machine.

SUMMARY OF THE INVENTION It is a technical object of the present invention to provide an injection molding machine which realizes the basic concept of switching operation as simple as possible and does not require a high production cost and is excellent in mass productivity.

[0007]

The gist of the present invention will be described with reference to the accompanying drawings.

A plurality of moving bodies 1 are juxtaposed at predetermined intervals in the moving direction, and an extruding rod 2 is protruded from each of the moving bodies 1, and at least one extruding rod 2 protruding from the moving body 1 is connected to the moving body 1. In an injection molding machine configured as an ejector rod for extruding and discharging a molded article 3, a movable rod 6 that moves to move the one moving body 1 without moving the other moving body 1 penetrates each moving body 1. And a connecting mechanism 7 for connecting the movable rod 6 or a member which is moved by the movement of the movable rod 6 to each moving body 1 is provided so as to be freely connected / disengaged. An engaging body 8 is provided in the through hole 21 of the rod 6 so as to be able to protrude and retreat.
Is formed, and the small-diameter portion 6A of the movable rod 6 advances and retreats but does not pass the large-diameter portion 6B, and the boundary between the small-diameter portion 6A and the large-diameter portion 6B passes through the notch edge 22. Part 6C has notched edge 22
The movable rod 6 and the moving body 1 are locked and connected to each other, and the engaging body 8 of the connecting mechanism 7 is moved so that one moving body 1 does not move the other moving body 1. And the other moving body 1 can be switched without moving one moving body 1 or both moving bodies 1 can be moved together. It relates to a molding machine.

[0009]

When the movable rod 6 is moved in a state in which the coupling mechanism 7 is operated to project the engaging body 8 into the through hole 21 of the movable rod 6 of the movable body 1, the small diameter portion 6A of the movable rod 6 is engaged. It penetrates the inside of the cutout edge 22 of the union 8. Accordingly, the moving body 1 does not move during this time, but when the movable rod 6 further moves, the large-diameter portion 6B (the boundary portion 6 between the small-diameter portion 6A and the large-diameter portion 6B).
C) abuts and locks on the notch edge 22. In this state, the movable body 1 is locked and connected to the movable rod 6, and the movable body 1 moves with the movement of the movable rod 6, whereby the pushing rod 2 protruding from the movable body 1 moves.

Conversely, when the coupling mechanism 7 is operated to retract the engaging member 8 from the through hole 21 or move in the retreating direction, the connection between the movable member 1 and the movable rod 6 is released, and the movable member 1 is disconnected. The movable rod 6 moves forward and backward without being moved.

By providing the connecting mechanism 7 on each moving body 1, the movement of each moving body 1 can be controlled separately, and the movement of the movable rod 6 with respect to the movement of the movable rod 6 by setting the positions of the small diameter portion 6A and the large diameter portion 6B. The time difference starting time of the body 1 can be controlled.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

Reference numeral 11 denotes a nozzle for injecting the resin 12, 13 denotes a sprue portion, 14 denotes a runner portion that branches right and left, 15 denotes a cavity portion, 16 denotes a parting line, and 17 denotes a moving body storage portion in a mold. is there.

In the present embodiment, a plate block-shaped first movable body 1A and a second movable body 1B are arranged side by side at predetermined intervals in the movable body storage section 17 and at respective movable permissible spaces.

The first mobile unit 1A is disposed on the front side (the cavity 15 side), the second mobile unit 1B is disposed on the rear side, and the first mobile unit 1A is extended toward the cavity 15 Ejector rod 2A for extruding and ejecting molded product 3 after opening mold
And an ejector rod 2A 'for pushing and ejecting the runner 4 formed by the runner portion 14 which is an unnecessary molded product is protruded as the pushing rod 2, and the second moving body 1B shuts off the runner portion 14 and the cavity portion 15. And the cavity
Push out gate cut pin 2B to close 15 and push rod 2
And projecting toward the cavity 15 through the first moving body 1A.

The first and second moving bodies 1A and 1B have through holes.
The movable rod 6 is formed so as to penetrate through the through hole 21 so as to penetrate from the rear side of the second moving body 1B to the front side and from the rear side of the first moving body 1A to the front side. I have arranged.

There is provided a connecting mechanism 7 for switching whether the movable rod 6 and the second movable body 1B are locked or disconnected, and also connects the movable rod 6 and the first movable body 1A. A connection mechanism 7 is provided which can switch between a stop connection and a connection release.

The connecting mechanism 7 has an engaging member 8 which can protrude and retreat in a through hole 21 of the movable rod 6 of the moving body 1.
A notch edge 22 that is locked to the movable rod 6 at the tip of the engagement body 8.
The small-diameter portion 6A of the movable rod 6 advances and retreats through the notch edge 22, but does not pass through the large-diameter portion 6B, and the boundary 6C between the small-diameter portion 6A and the large-diameter portion 6B is formed at the notch edge 22. The movable rod 6 and the movable body 1 are locked so as to be locked and connected.

More specifically, the engaging body 8 is formed in a plate shape that protrudes and retracts toward the inside of the through hole 21, and a semicircular cutout edge 22 is formed at the lower end of the projecting end of the plate-shaped engaging body 8. The notch opening diameter of the notch edge 22 is set to the small diameter portion 6A
When the movable rod 6 advances toward the cavity 15 side, the boundary step between the small-diameter portion 6A and the large-diameter portion 6B is set. The portion 6C abuts and locks around the notch edge 22. At this time, the movable rod 6 presses the engaging body 8, and the movable body 1 moves forward (locks and connects) together with the movable rod 6. .

In this embodiment, the engaging member 8 of the connecting mechanism 7 for connecting / disconnecting the second moving body 1B and the movable rod 6 includes:
The notch edge 22 is formed at the base of the large-diameter notch edge 22 'that can pass through the large-diameter portion 6B.

Accordingly, when the engaging body 8 is lowered and protruded into the through hole 21 so that the notch edge 22 is engaged with the large-diameter portion 6B (boundary step portion 6C) of the movable rod 6, the movable rod 6 moves forward. The large diameter portion 6B of the movable rod 6
Is locked, the movable body 1B and the movable rod 6 are connected, the movable body 1B moves together with the movable rod 6, and the pushing rod 2 provided on the movable body 1B moves.

In the present embodiment, the tip of the movable rod 6 advances through the sprue portion 13 toward the nozzle portion 11, and the unnecessary molding (sprue runner) in the sprue portion 13 is moved into the nozzle portion 11 by the nozzle portion 11. A resin push-back pin 2D that is pushed back in a molten state by the heat of 11 is provided.

The sprueless method of pushing the sprue runner back to the nozzle portion 11 before opening the mold is a molding method invented by the applicant. (Japanese Patent Application No. 5-84732, Japanese Patent Application No. 6-4103, etc.) That is, the nozzle portion 11 (resin injection portion)
From the left and right cavity parts 15 through the sprue part 13
In the resin molding method in which the molten resin 12 is fed into the cavity via the runner portion 14 and solidified, the molten resin 12 is fed into the cavity 15 by moving a screw, and the molded product 3 in the cavity 15 is hardened. Thereafter, the resin push-back pin 2D is moved, and the unnecessary molded product (sprue runner) in a hardened state is pushed back to the resin injection unit 11, and the unnecessary molded product 4 is melted into the resin injection unit 11 by the heat of the resin injection unit 11. Push back. At this time, the gate portion (runner portion 14) into the cavity 15 is closed on the side of the resin push-back pin 2D by the movement of the resin push-back pin 2D, and the resin push-back pin 2D is closed.
Insert the moving tip of D into the resin injecting section 11
Is to close.

The push-back rod 2D allows the sprue section
By pushing back the 13 unnecessary molded products, molding and discharging of sprueless products becomes possible, and saving of resin material is achieved. In addition, the nozzle portion 11 can be closed by the tip of the push-back rod 2D. Even if the nozzle portion 11 and the sprue portion 13 are designed to have a large diameter, resin leakage can be reliably prevented.
Since the diameter of 13 is large and the resin (unnecessary molded product) in the sprue portion 13 is in a semi-molten state, there is no problem in the molded product 3 and since the small-diameter nozzle portion 11 is not required, injection resistance is low and low-pressure injection can be performed. Thus, warpage and deformation can be reduced, and variations in the quality of the molded product 3 per one shot can be reduced.

Further, in this embodiment, the tip of the resin push-back pin 2D is cut to form a tip splitting section (shuttle rod portion) 2D ', and the resin push-back pin 2D (movable rod 6) is moved to move the tip. Dividing part (shuttle rod part)
2D 'is inserted into the resin injection portion 11, and the unnecessary molded product in the sprue portion 13 is pushed back into the resin injection portion 11. When the resin push-back pin 2D returns and moves (retreats), the tip dividing portion (shuttle rod portion) is used. 2) The 2D 'does not move, remains inserted in the resin injection portion 11, and is configured to return and move in the left-end tip dividing portion 13.

The movable rod 6 moves to move the first moving body 1A and the second moving body 1B forward through the first moving section 1A and the second moving section 1B, respectively. It is configured to move back by urging force.

Therefore, in this embodiment, the gate cut pin 2B as the push rod 2 and the two types of ejector rods 2A, 2A 'are alternately moved via the moving bodies 1A, 1B with a time lag, and the resin is pushed back again. It is configured to control the movement of the pin 2D, and operates as follows.

The engaging member 8 of the connecting mechanism 7 provided on the second moving body 1B further descends at a position where the movable rod 6 passes through the large-diameter notch edge 22 'so that the notch edge 22 has a large diameter. It descends to a position where it can be locked to the part 6B.

When the movable rod 6 advances in this state, the small-diameter portion 6A passes through the notch edge 22, but the large-diameter portion 6B (boundary step portion 6C) abuts and locks around the notch edge 22. In this state, the second moving body 1B is pushed forward by the movable rod 6 via the engaging body 8, and the gate cut pin 2B provided on the second moving body 1B moves forward, and the cavity 15 and the runner 14 are moved. And the cavity 15 is closed.

Then, the engaging members 8 of the two connecting mechanisms 7 provided on the first moving body 1A and the second moving body 1B move up and down, and the movable rod 6 moves forward without being locked to the engaging body 8. Then, the resin push-back pin 2D at the tip of the movable rod 6 is inserted into the sprue portion 13 and protrudes forward, and the unnecessary molded product in the sprue portion 13 is pushed back into the resin injection portion 11 by the sprueless method.

Then, the movable rod 6 retreats again, and after the mold is opened from the parting line 16, the movable rod 6 advances again. At this time, the engaging member 8 of the coupling mechanism 7 provided on the second moving body 1B remains raised and retracted, and the first moving section 1A
The engaging body 8 of the coupling mechanism 7 provided in the above is protruded downward.

Therefore, in this case, when the movable rod 6 moves forward, the second moving body 1B does not move at all,
B (boundary step 6C) abuts and locks around the notch edge 22 of the engaging body 8 of the first moving body 1A, and moves only the first moving body 1A forward through the engaging body 8 to eject the ejector rod 2A.・
The molded product 3 and the runner 4 are extruded from the sprue portion 13 and the runner portion 14, respectively, and are dropped and discharged.

The first mobile unit 1A and the second mobile unit 1B
The alternate movement control based on the connecting mechanism 7 can be configured in various ways, and when the movable rod 6 further moves forward with the second moving body 1B moved and the pushing rod 2 protruded.
The first moving body 1A may be moved to move the first moving body 1A to protrude the pushing rod 2, or the movable rod 6 may be returned once and the second moving body 1B may be returned and moved as in the present embodiment. The first moving body A1 and the second moving body 1B as in the embodiment.
May be moved together, or only the first moving body 1A may be designed to move.

[0034]

Since the present invention is constructed as described above, the movement of each moving body is controlled only by controlling the protrusion / retreat of the engaging body and moving the movable rod forward / backward. It is possible to realize an injection molding machine which can be switched and moved, and can control the rod movement at a low cost, which is extremely excellent in mass productivity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a movable body of this embodiment does not move, only a movable rod moves, and a resin push-back pin advances.

FIG. 2 is a cross-sectional view illustrating a state in which an extruding rod of a first moving body has moved after a mold is opened according to the present embodiment.

FIG. 3 is a longitudinal sectional view showing a connection mechanism of the present embodiment.

FIG. 4 is an explanatory perspective view of the connection mechanism of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moving body 2 Extruded rod 3 Molded product 6 Movable rod 6A Small diameter part 6B Large diameter part 6C Boundary part 7 Connecting mechanism 8 Engagement body 21 Through hole 22 Notch edge

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho-59-94814 (JP, U) Japanese Utility Model Sho-55-96722 (JP, U) Japanese Utility Model Sho-63-111250 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (1)

(57) [Claims] 1. A plurality of moving bodies are juxtaposed at predetermined intervals in the moving direction, and an extruding rod is protruded from each of the moving bodies, and at least one extruded rod protruding from the moving body is formed into a molded product. In an injection molding machine configured with an ejector rod for extruding and discharging, a movable rod which moves to move the one moving body without moving the other moving body is provided in a penetrating state in each moving body, and the movable rod or A connecting mechanism for connecting the movable member and each moving body to each other by moving the movable rod is provided so as to be freely connectable / disengageable. The connecting mechanism projects and retracts the engaging body into the through-hole of the movable rod of the moving body. A notch edge is formed at the tip of the engaging body to be engaged with the movable rod, and the small-diameter portion of the movable rod passes through the notch edge but does not pass through the large-diameter portion,
The boundary between the small-diameter portion and the large-diameter portion is locked at the notch edge so that the movable rod and the moving body are locked and connected, and the engaging body of this connection mechanism is moved to form one moving body. A configuration that can be switched between a case in which the other moving body is moved without moving and a case in which the other moving body is moved without moving one moving body or a case in which both moving bodies are moved together. An injection molding machine characterized by the following.