JPH0446214B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an injection device that measures and injects a fixed amount of injection material such as rubber into a mold.

BACKGROUND ART Conventional injection devices include, for example, screw type injection devices. This will be explained in detail with reference to FIG. 6. 40 is an injection device. A device main body 41 of this injection device 40 includes a horizontally elongated heating cylinder 43 having a hopper (supply port) 42 at the top;
The metering cylinder 45 has a plunger 44 and stands perpendicularly to the heating cylinder 43, and an injection nozzle 46 projects from the lower end of the metering cylinder 45, forming a substantially T-shape. A long screw 49 is rotatably disposed inside the heating cylinder 43 via a bearing case 47, an electric motor 48 with a reduction gear, a hydraulic motor, or the like. Further, the plunger 44 in the metering cylinder 45 is connected to an injection cylinder 50, and is moved up and down by a predetermined stroke by a limit switch 51 or the like. Further, a switching valve 53 is rotatably disposed at a branch portion 52a of the material passage 52 that communicates the heating cylinder 43 with the metering cylinder 45 and injection nozzle 46. The injection nozzle 46 is provided so as to be able to come into contact with and separate from the sprue 55 of the mold 54. This mold 54 consists of an upper mold 56 on which a sprue 55 is formed and a lower mold 58 connected to a mold clamping piston 57.
6 and the lower die 58 form a cavity 59 having a predetermined shape and communicating with the sprue 55.

When molding, for example, an automobile door weather strip, anti-vibration rubber, etc. using the mold 54, first, a strip-shaped rubber material (injection material) 60 is supplied to the hopper 42, and the screw 49 Rotate. As the screw 49 rotates, the rubber material 61 is degassed and plasticized within the heating cylinder 43. This plasticized rubber material 61 is introduced into the metering cylinder 45 via the material passage 52 and metered to a certain amount. Next, the switching valve 53 is switched, the injection nozzle 46 is brought into contact with the sprue 55 of the mold 54, and the plunger 44 is lowered to inject the predetermined amount of the plasticized rubber material 61 into the cavity 59 of the mold 54. injection injection. Next, the mold 54 is heated to vulcanize the rubber material 61 to obtain a molded product such as the automobile door weather strip.

Problems to be Solved by the Invention In the screw type injection device 40, the hopper 42 supplies the strip-shaped rubber material 60.
Since the heating cylinder 4 is open to the atmosphere, air tends to get mixed in when the rubber material 60 is plasticized, and the defoaming process is incomplete, resulting in variations in the process.
There was a problem in that the rubber material 61 plasticized in the cylinder 3 was not densely packed, and the rubber material plasticized to a constant density could not be uniformly introduced into the metering cylinder 45 at all times. As a result, the measured value of the measuring cylinder 45 tends to vary, and the amount of plasticized rubber material drawn out into the cavity 59 of the mold 54 6
There was an excess or deficiency in the amount of 1, resulting in a low yield of molded products and an increase in the number of post-process steps, resulting in poor productivity.

In addition, pellet-shaped rubber materials are used,
If you try to use a longer screw to de-foam and uniformly plasticize the rubber material,
This has had the disadvantage of increasing the manufacturing cost of molded products and devices due to an increase in the number of man-hours in pre-processing, such as cutting the rubber material into a predetermined shape, and an increase in the size and complexity of the structure of the device body.

Therefore, the present invention aims at simplifying the entire apparatus, and moreover, is capable of introducing a constant amount of uniformly plasticized injection material into a measuring cylinder and leading it out from the measuring cylinder to the injection nozzle side. It provides equipment.

Means for Solving the Problems The injection device of the present invention includes a plunger that is removably inserted into the injection material supply port, a charge cylinder equipped with a degassing device and a heating device, and a plunger. , a metering cylinder that is communicated with the charge cylinder and temporarily stores a certain amount of injection material, and a branch part of a material passage that connects the charge cylinder, the metering cylinder, and an injection nozzle that comes into contact with the sprue of the mold. a switching valve disposed in the material passage for introducing the injection material supplied from the charge cylinder into the measuring cylinder side and leading out the injection material from the measuring cylinder to the injection nozzle side; and a plurality of plasticizing plates for plasticizing.

Function The injection material supplied into the charge cylinder from the supply port is deaerated and heated by the deaerator and heating device, and uniformly plasticized by the plunger and plasticizing plate without mixing air, and then transferred to the metering cylinder. A certain amount is temporarily stored within. The plasticized injection material in this metering cylinder is further plasticized by the plunger and plasticizing plate, and is switched to the injection nozzle side by the switching valve and is always injected in a fixed amount into the mold, allowing molding. Product quality and yield will further improve.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. 1 to 5.

In FIGS. 1 and 2, 1 is an injection device. A lower flange 3a of a large-diameter cylindrical charge cylinder 3 and a lower flange 4a of a small-diameter cylindrical metering cylinder 4 are mounted on the upper surface of the main body 2 of the injection device 1, and a holder 5 is mounted on one side. Injection nozzles 6 are screwed onto the holder 5 via the lower flange portion 5a, and are fixed with bolts 7, respectively.

A large-diameter plunger 8 is disposed in the upper end opening (supply port) 3b of the charge cylinder 3 so as to be freely insertable and removable. A piston part 8a is screwed into the lower part of the plunger 8, and a midway part 8b is provided with a piston part 8a.
A substantially disc-shaped cap 9 that seals the supply port 3b of the charge cylinder 3 is slidably inserted therein. A forced vertical movement device such as a spring 10 or pneumatic or hydraulic pressure is interposed between the cap 9 and the upper part 8c of the plunger 8. The tip of a rod 11 of a hydraulic cylinder is screwed onto the upper part 8c of the plunger 8. Further, a heater (heating device) 12 made of heating wire or heat medium oil is installed around the outer circumferential surface of the charge cylinder 3, and on the upper part thereof,
A deaerator 13 is attached. This deaerator 13
is composed of a vacuum pump 14, an accumulation tank 15, a switching valve 16, and a pipe 17 that communicates these with the inside of the charge cylinder 3. In addition, the cap 9 and the charge cylinder 3
The supply port 3b, the cap 9, and the plunger 8 are each sealed with an O-ring or the like (not shown).

A small-diameter plunger 18 is disposed inside the measuring cylinder 4 so as to be movable up and down. The lower part of the plunger 18 is a piston part 18a, and a freely settable limit switch 19 or a tacho generator or the like is disposed on the midway part 18b side to move the piston part 18a up and down by a predetermined stroke. Upper part 1 of the plunger 18
The tip of the hydraulic cylinder rod 20 is screwed onto 8c. Furthermore, a heater (heating device) 21 made of a heating wire, heat medium oil, or the like is installed around the outer peripheral surfaces of the measuring cylinder 4 and the device main body 2, so that the temperature can be adjusted.

Further, a material passage 22 is formed in the apparatus main body 2 and the holder 5, which communicates the charge cylinder 3 with the metering cylinder 4 and the injection nozzle 6. A switching valve 23 is rotatably disposed at the branch portion 22a of the material passage 22. Also, the charge cylinder 3 side end of the material passage 22, the measuring cylinder 4 side end, the intermediate part between the switching valve 23 and the charge cylinder 3, and the device main body 2 and the holder 5.
A removable plasticizing plate 24 is disposed at the joint portion of each. These plasticized plates 2
4, as shown in FIG. 5, is formed into a disk shape and has a plurality of small holes 24a passing through it.

Further, the leg portion 2a provided at the lower part of the device main body 2 is slidably placed on a rail 26 laid on a base 25. The other side of the main body 2 is connected to a rod 29 of a hydraulic cylinder 28 fixed to a bracket 27 of the base 25. Further, a lower mold 31 of a mold 30 is fixed at a position on the base 25 facing the injection nozzle 6. The lower mold 31 and the upper mold 33, which are movable up and down so as to come into contact with and separate from the mold clamping piston 32, form a sprue 34 with which the injection nozzle 6 comes into contact, and a cavity 35 that communicates with the sprue 34.

In addition, 2b is a temperature control heater hole or a heat medium distribution pipe formed in the main body 2 of the apparatus, 36 is a lump-like (for example, cylindrical) rubber material (injection material), and 3
7 is a plasticized rubber material.

With the injection device 1 having the structure of the above embodiment, the mold 3
Plasticized rubber material 3 in cavity 35 of 0
7 is injected to vulcanize and mold a molded product such as an automobile door weather strip or anti-vibration rubber. First, the plunger 8 in the charge cylinder 3 is disengaged, and the plunger 8 is injected from the supply port 3b. For example, a cylindrical rubber material 36 is supplied into the charge cylinder 3, as shown in FIG. Next, plunger 8
Insert from the supply port 3b of the charge cylinder 3,
The piston portion 8a lightly presses the rubber material 36 downward. At this time, the cap 9 is urged toward the charge cylinder 3 by the elastic force of the spring 10, completely sealing the supply port 3b. Next, as shown in FIG. 4, the charge cylinder 3 is
Evacuate the inside. The charge cylinder 3 has a heater 12
The temperature is regulated to the set temperature.

Then, when the switching valve 23 is switched to the state shown in FIG. 1 and the rubber material 36 is pressed downward by the plunger 8, the rubber material 3
The material 6 is plasticized by a plurality of plasticizing plates 24 arranged in the temperature-controlled material passage 22, and is gradually introduced into the measuring cylinder 4 by pushing up the plunger 18 inside the measuring cylinder 4. When the plunger 18 moves up by a predetermined stroke, the limit switch 19 or the like stops the rising of the plunger 18 and releases the pressure, and also stops the descending of the plunger 8 in the charge cylinder 3 and releases the pressure.
Thereby, a certain amount of plasticized rubber material 37 can always be temporarily stored in the measuring cylinder 4.

Next, as shown in FIG.
Slide the main body 2 of the device until the tips of the two come into contact with each other. Then, when the switching valve 23 is switched so that the plasticized rubber material 37 can be led out from the metering cylinder 4 to the injection nozzle 6 side, and the plunger 18 in the metering cylinder 4 is lowered, the inside of the metering cylinder 4 is lowered. The plasticized rubber material 37 is further plasticized by the plasticizing plate 24 disposed in the material passage 22 and is injected into the cavity 35 of the mold 30.

After injecting the sufficiently plasticized rubber material 37 into the cavity 35 of the mold 30, slide the device main body 2 back to its original position and repeat the injection process described above until the rubber material 36 in the charge cylinder 3 runs out. Repeat multiple times. As a result, the rubber material 37 that has been sufficiently plasticized and accurately measured to a certain amount can be constantly injected into the cavity 35 of the mold 30, so that the molded product vulcanized by the mold 30 can be injected into the cavity 35 of the mold 30. The quality and yield will further improve. In addition, there are advantages in that the number of post-process steps is reduced, productivity is improved, and the manufacturing cost of molded products can be reduced.

Furthermore, since the entire device is simplified, equipment costs and maintenance costs such as failures can be further reduced, and the operating rate can be greatly improved.

Effects of the Invention As described above, according to the present invention, the injection material supplied to the charge cylinder is sufficiently plasticized by the pressure of the plunger and the plasticizing plates disposed in the material passage while deaerating the periphery of the injection material. By temporarily storing a certain amount in the metering cylinder, it is possible to inject a precisely measured amount of injection material into the mold at a constant density at all times. Therefore, the quality and yield of molded products can be further improved, and productivity can be increased. In addition, the number of steps in post-processing can be significantly reduced, resulting in lower costs. In addition, by using plunger types for both the charge cylinder and metering cylinder, the entire device can be made more compact compared to conventional screw type cylinders, significantly reducing installation space and maintenance costs. It is possible to significantly reduce equipment costs.

[Brief explanation of the drawing]

1 and 2 are overall sectional views showing an embodiment of the present invention, FIGS. 3 and 4 are enlarged sectional views of the charge cylinder, and FIG. 5 is a perspective view of the plasticizing plate.
FIG. 6 is an overall schematic sectional view of a conventional device. 1... Injection device, 3... Charge cylinder, 3
b... Supply port, 4... Measuring cylinder, 6... Injection nozzle, 8... Plunger, 12... Heater (heating device), 13... Deaerator, 18... Plunger, 22... Material passage, 22a...branch, 23
...Switching valve, 24...Plasticizing plate, 30
... Mold, 34 ... Sprue, 36, 37 ... Rubber material (injection material).

Claims (1)

[Claims] 1. A plunger is removably inserted into the injection material supply port, and a charge cylinder is equipped with a deaerator and a heating device, and the plunger is connected to the charge cylinder to supply a certain amount of injection material. and a metering cylinder for temporarily storing the injection material supplied from the charge cylinder. a switching valve for introducing the material into the measuring cylinder side and leading it out from the measuring cylinder to the injection nozzle side, and a plurality of plasticizing plates disposed in the material passage and plasticizing the injection material. An injection device characterized by: