JPH07156228A - Injection molding device - Google Patents

Abstract

PURPOSE:To completely remove an old material adhered to a cylinder wall in the early stage by disposing a piston with an end face forming an inclined face for the cycling movement of a resin material. CONSTITUTION:An injection plunger 5 is fed into an injection cylinder 3 of an injection heating cylinder 2, and the vicinity of end of the injection cylinder 3 is communicated with a meter heating cylinder 7 through a passage 8. An end face 18 of the injection plunger 5 is inclined to the axial line of the plunger. When a screw 9 is revolved, a new resin material is metering compressed into the injection cylinder 3, and successively a hydraulic pressure pump 14 is driven, and when hydraulic pressure is applied to a right end face of an injection ram 6, high pressure is applied to the new resin material while the injection plunger 5 is moved in the left direction. At that time, the left end face of the injection plunger 5 is inclined, and the pressure is applied to the new resin material in the direction inclining from the axial line to start the circulating movement. As a result, an old resin material adhered to an inner wall of the injection cylinder 3 is peeled off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding device. This device is an injection molding device that performs cleaning by pushing out the old resin material remaining in the injection cylinder.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Laid-Open No. 60-64817 discloses a method of adding a cleaning agent when changing materials because a material mixed with a colorant adheres to the inner wall of a cylinder in a resin injection molding apparatus. Has been. The aforementioned publication discloses a method in which a required amount of cleaning material Q is charged into the hopper 3 and the start button of the material changing circuit is operated to automatically repeat injection molding to extrude and clean the material remaining in the cylinder. Further, Japanese Patent Laid-Open No. 26720/1990 is known as a method for charging and cleaning a new material.

In the above publication, after a new material is put into the hopper 5, the arithmetic control means 23 drives the second motor 10 to rotate the screw 7
There is known a method in which the cleaning effect is enhanced by retreating at a predetermined speed and vibrating at high speed. Further, as a method of injecting a cleaning agent, JP-A-5-57750 is known. In the publication, an injection valve having a press-fitting pump for mixing a coloring agent or a cleaning agent is provided,
There is a press-fitting device that delivers a coloring agent or a cleaning agent to the discharge channel.

[0004]

However, since the cleaning agent or the new material does not cause a swirling motion in the above-mentioned publication,
It is not possible to completely remove the material stuck to the inner wall of the cylinder. There is also the problem of requiring a lot of cleaning agents or new materials. SUMMARY OF THE INVENTION It is an object of the present invention to provide an injection molding apparatus that gives a swirling motion to a new material for resin molding and completely removes the old material adhering to the cylinder wall in an early stage.

[0005]

In order to achieve the above object, the first invention is to inject a hopper that stores a resin material, a measuring heating cylinder that receives the supply of the resin material from the hopper, and the resin material. An injection heating cylinder, an injection nozzle for supplying a resin material into the mold from the injection heating cylinder, and a metering heating cylinder and a heater for heating the injection heating cylinder. And a piston having an end face forming an inclined surface. A second aspect of the invention is a hopper that stores a resin material, a measuring heating cylinder that receives the supply of the resin material from the hopper, an injection heating cylinder that injects the resin material, and a resin material from the injection heating cylinder into the mold. An injection nozzle for supply, a metering heating cylinder, and a heater for heating the injection heating cylinder. In the injection heating cylinder, the resin material is provided in the injection heating cylinder. It is characterized by

[0006]

In the injection molding apparatus having the above structure, the first
In the invention, when the resin material is supplied from the hopper to the heating cylinder for measurement and further supplied to the injection heating cylinder, it is melted by the heater and supplied into the injection heating cylinder, and is added by the piston having the end face forming the inclined surface. By pressing, the pressure applied to the resin material acts in a direction inclined from the axial direction and the resin material is pressed while rotating, so that the resin material attached to the inner wall of the injection heating cylinder is removed. In the second aspect of the invention, since the concave groove is formed in the changing portion of the injection cylinder diameter and the injection nozzle inner diameter, the flow velocity of the resin in the concave groove can be increased and the old resin material can be removed quickly.

[0007]

EXAMPLES The first invention will be specifically described with reference to the following examples. 1 and 2, an injection heating cylinder 2 for injecting a resin material is fixed on a surface plate 1. The injection heating cylinder 2 is composed of an injection cylinder 3 and an injection cylinder 4, and an injection plunger 5 is provided in the injection cylinder 3. Is inserted and the right end is an injection ram 6, the diameter of which is larger than that of the injection plunger 5. The vicinity of the tip of the injection cylinder 3 communicates with the measuring and heating cylinder 7 via a passage 8. A screw 9 is fitted into the cylinder 7a of the measuring and heating cylinder 7, the left end thereof has a conical shape, and the right end thereof is connected to the hydraulic motor 10 to measure and compress the resin material.

The cylinder 7a of the metering and heating cylinder 7 and the hopper 12 are connected via a passage 11 near the center of the cylinder 7a. The left end of the injection cylinder 3 is provided with an injection nozzle 13 and a diameter changing portion 3 a of the injection cylinder 3. The right end of the injection cylinder 4 is connected to the hydraulic pump 14. The left end of the injection nozzle 13 comes into contact with the fixed mold 15 and
Is fixed to a fixed platen 15a fixed by a tie bar 18. A movable mold 16 is provided opposite to the fixed mold 15. The movable mold 16 is fixed to the movable plate 16a, and the movable plate 16a slides on the tie bar 18 and the surface plate 1. The end face 18 of the injection plunger 5 is inclined with respect to its axis. The fixed mold 15 and the movable mold 16 are collectively referred to as a molding mold 17.

Next, the operation of the embodiment according to the first invention will be described. When the molding with the old resin material is completed and the fixed mold 15 and the movable mold 16 are polymerized and the new resin material is charged into the hopper 12, the screw 9 is rotated by the hydraulic motor 10. The new resin material is metered and compressed into the injection cylinder 3, and the injection cylinder 3
Fill the space inside. In this state, the injection cylinder 3
No hydraulic pressure is applied to the injection ram 6 inside the injection cylinder 4. Then, when the hydraulic pump 14 is driven and hydraulic pressure is applied to the right end surface of the injection ram 6, a high pressure is applied to the new resin material while the injection plunger 5 moves leftward.

At this time, since the left end surface of the injection plunger 5 is inclined, pressure is applied to the new resin material in a direction inclined with respect to the axis, and the new resin material makes a swiveling motion. As a result, the old resin material adhering to the inner wall of the injection cylinder 3 is peeled off and discharged from the injection nozzle 13 toward the inside of the molding die 17. The old resin material is removed by repeating this several times. 2 to 4 show a second embodiment of the injection plunger according to the first invention. The left end surface of the injection plunger 5A has saw teeth 25 as shown in FIG. The sawteeth 25 are formed radially from the axial center of the injection plunger 5A and are formed of a gentle inclined surface 25a and a steep inclined surface 25b.

The central portion is circular as shown in FIG.
It is 6. FIG. 4 is a perspective view of the injection plunger. When the new resin material is pressed, the new resin material is pressed at an angle with the axis, so that the swirling motion is caused and the stuck old resin material can be removed. 5 to 7 are the first
3rd Embodiment of the injection plunger which concerns on invention of FIG. A ring 27 is fitted by a pin 28 on the left end surface of the injection plunger 5B. The outer diameter of the ring 27 is the injection plunger 5
It is formed the same as B.

As shown in FIG. 5, the saw teeth 29 are formed radially from the injection plunger 5B and are composed of a gentle inclined surface 29a and a steep inclined surface 29b. 6 is a side view thereof, and FIG. 7 is a perspective view thereof. When pressure is applied to the new resin material by the ring 27, the two inclinations pressurize the new resin material in the axial direction and in the inclined direction, causing the ring 27 to make a swiveling motion and peeling off the stuck old resin material. 8 to 9 show a first embodiment of the concave groove provided in the changing portion of the injection cylinder diameter according to the second invention. A plurality of concave grooves 30 are formed in the conical surface 31 formed in the changing portion of the diameter of the injection cylinder 3 and the diameter of the hole 35 of the injection nozzle 13.
As shown in the enlarged view of FIG. 9, concave grooves 30 having a predetermined width are formed radially from the center of the hole 35 of the injection nozzle 13. During pressurization, the flow velocity of the resin is increased to remove the stuck resin. FIG. 10 shows a second embodiment of the groove according to the second invention. The groove 32 is narrowed toward the center of the hole 35 of the injection nozzle 13. The flow velocity is higher than that in FIGS. 8 to 9. Figure 1
1 shows a third embodiment of the concave groove provided in the diameter changing portion of the injection cylinder according to the second invention.

As shown in FIG. 11, a groove 33 may be provided obliquely with the axis center removed. FIG. 12 shows a fourth embodiment of the groove. The spiral groove 34 may be formed toward the center of the hole. FIG. 13 shows a first embodiment of the holes provided in the injection cylinder diameter changing portion according to the second invention. Injection cylinder 3
A plurality of holes 34 in the axial direction and a plurality of holes 36 in the diameter direction of the holes 35 of the injection nozzle 13 are provided on the conical surface 31 provided at the changing portion of the diameter and the inner diameter of the injection nozzle 13, and are mutually provided in the circumferential direction. It is in communication. Pressurization of the new resin material causes the old resin material to flow from the inner wall of the injection cylinder 3 through the passage 34 to the passage 36 to increase the flow rate thereof and to pass through the inner wall of the injection cylinder 3.

[0014]

Since it is constructed as described above, the first
The invention has the following effects. That is, a force is applied to the replaced new resin material in a direction tilted with respect to the axial direction of the injection plunger, and as a result, a swirling motion occurs in the new resin material, so the old resin material stuck to the wall is easily peeled off and washed. Can be done quickly, saving a great deal of time and material. In the second aspect of the present invention, since the groove or hole is provided in the changing portion of the diameter of the injection cylinder and the diameter of the injection nozzle, the flow velocity of the resin at the time of injection is increased, and the old resin material stuck to the wall can be easily peeled off and the cleaning can be performed quickly. .

[0015]

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of an injection molding machine according to a first invention.

FIG. 2 is a front view of a second embodiment of the injection plunger according to the first invention.

FIG. 3 is a side view of a second embodiment of the injection plunger according to the first invention.

FIG. 4 is a perspective view of a second embodiment of the injection plunger according to the first invention.

FIG. 5 is a front view of a third embodiment of the injection plunger according to the first invention.

FIG. 6 is a side view of a third embodiment of the injection plunger according to the first invention.

FIG. 7 is a perspective view of a third embodiment of the injection plunger according to the first invention.

FIG. 8 is a vertical cross-sectional view of a first embodiment of a groove according to the second invention.

FIG. 9 is a sectional view taken along the arrow P of the first embodiment of the groove according to the second invention.

FIG. 10 is a sectional view of a second embodiment of a groove according to the second invention.

FIG. 11 is a sectional view of a third embodiment of a groove according to the second invention.

FIG. 12 is a sectional view of a fourth embodiment of a groove according to the second invention.

FIG. 13 is a longitudinal view of the first embodiment of the hole according to the second invention.

[Explanation of symbols]

 2 Injection heating cylinder 3 Injection cylinder 3a Diameter changing part 5 Injection plunger 7 Measuring heating cylinder 7a Measuring cylinder 9 Screw 12 Hopper 13 Injection nozzle 18 End surface

Claims (2)

[Claims] 1. A hopper for storing a resin material, a metering heating cylinder for receiving the resin material supplied from the hopper, an injection heating cylinder for injecting the resin material, and a resin material for supplying into the mold from the injection heating cylinder. Injection nozzle, a metering heating cylinder, and a heater that heats the injection heating cylinder. An injection characterized by comprising a piston having an end face that forms an inclined surface so that the resin material swirls. Molding equipment. 2. A hopper that stores a resin material, a measuring heating cylinder that receives the resin material supplied from the hopper, an injection heating cylinder that injects the resin material, and a resin material that supplies the resin material into the mold from the injection heating cylinder. An injection nozzle for heating, and a heater for heating the injection heating cylinder and a heater for heating the injection heating cylinder, wherein the resin material is provided with a concave groove in the changing portion of the injection cylinder diameter and the injection nozzle inner diameter provided in the injection heating cylinder. An injection molding device characterized by: