JP3211733B2 - Stopping device for injection unit in injection molding machine and vertical 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 unit stopping device for an injection molding machine and a vertical injection molding machine for stopping the injection unit in a nozzle touch state in which a nozzle is pressed against a mold.

[0002]

2. Description of the Related Art As a vertical injection molding machine, as shown in FIG. 4, an upper plate 4 to which an upper die 3 is attached is provided on a lower plate 2 to which a lower die 1 is attached. An injection unit 7 for pressing the nozzle 6 of the heating cylinder 5 against the upper mold 3 and injecting the molten resin into the molding cavities of the molds 1 and 3 has a plate 9 supported by a pair of hydraulic cylinders 8. There is a known one that can be freely moved up and down.

This conventional vertical injection molding machine has a stopper 1
1, a detection switch 12 such as a limit switch and a dog 1
3 for stopping the injection unit 7. The stopper 11 is a guide rod 1 for guiding the injection unit 7.
4, the detection switch 12 is attached to the plate 9, and the dog 13 is attached to the hydraulic cylinder 8. The approach movement of the injection unit 7 to the molds 1, 3 by the hydraulic cylinders 8, 8 is performed by the dog 13. After detecting the movement of the detection switch 12 to reduce the moving speed of the injection unit 7, the injection unit 7 is brought into contact with the stopper 11 without shock, and the injection unit 7 is pressed with the nozzle 6 pressed against the mold 3. Is stopped.

[0004]

By the way, there are various types of nozzles 6 which are pressed into contact with the mold 3 to directly inject the molten resin into the molding cavity, and are provided in various sizes, which are suitable for the type of the mold and the resin. The molding is done by replacing it with the one to be molded.

When the nozzle 6 is replaced with a nozzle 6 having a different length, the approaching movement of the injection unit 7 to the mold 3 naturally changes according to the length of the nozzle 6 to be used. Therefore, the mounting position of the stopper 11, the detection switch 12 and the dog 1
Both of the three related positions must be adjusted one by one according to the length of the nozzle 6 to be used, which is troublesome and time-consuming, and there is a complain that the number of parts is large and the structure is complicated. In addition, there is a problem that the injection unit 7 supported by the hydraulic cylinders 8, 8 tends to descend with time due to oil leakage in the hydraulic circuit.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device for stopping an injection unit in an injection molding machine in which adjustment operation is easy when a nozzle having a different length is replaced. Another object of the present invention is to provide a device for stopping an injection unit in an injection molding machine having a simple structure. Another object of the present invention is to provide a vertical injection molding machine which is free from oil leakage itself and has good operability.

[0007]

In order to achieve at least one of the above-mentioned objects, according to the first aspect of the present invention, the contact portion of the injection unit is brought into contact with the moving unit when the injection unit approaches the mold. A stopper for stopping the injection unit in a state where the nozzle of the injection unit is pressed against the mold, and a dog is operated immediately before the contact portion of the injection unit comes into contact with the stopper to detect the approach movement of the injection unit. In a device for stopping an injection unit in an injection molding machine having a detection switch, the detection switch is attached to one of the stopper and the injection unit, and the other of the stopper and the injection unit is also used for the dog. did.

[0008] In the injection unit stopping device of the injection molding machine described above, when replacing the nozzle with a nozzle having a different length, it is only necessary to adjust the mounting position of the stopper.
Moreover, there is no need to provide the dog as a separate component.

In the above-mentioned stopping device, the stopper can be detachably mounted on the mounting plate on which the mold is mounted by means of a bracket. Further, the stopper may be constituted by a pair of semi-circular members, and the pair of semi-circular members may be provided by being annularly fitted to a guide rod for guiding the injection unit.

According to a fourth aspect of the present invention, there is provided a vertical injection molding machine having the above-mentioned stopping device, wherein the moving device uses a screw mechanism.

In this vertical injection molding machine, unlike a vertical injection molding machine using a hydraulic cylinder as a moving device, troubles caused by oil leakage can be avoided, and the stop position of the injection unit can be adjusted. And easy operability is obtained.

[0012]

Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show an embodiment of the present invention. The stopper 11 includes a pair of semicircular members 11a and 11b.
The semicircular members 11a and 11b are fitted in a ring shape on the guide rod 14, and a plurality of semicircular members 11a and 11b are inserted from each through hole 16a of the bracket 16 to each through hole 11c of the semicircular member 11a (four in the figure). ) Are respectively inserted, and the bolts 17 are screwed into the respective screw holes 11d of the semicircular member 11b and tightened, so that the bolts 17 can be simultaneously fixed to the guide rod 14 and the bracket 16. ing. The bracket 16 is detachably attached to the upper panel (mounting panel) 4 with a plurality of mounting bolts 18.

The detection switch 12 is mounted on the injection unit 7 by fixing means such as bolts (not shown) so that the mounting position can be adjusted up and down, and the stopper 11 also serves as a dog.
Is activated by the semicircular member 11b to output a detection signal.

Reference numeral 21 denotes a moving device which replaces the hydraulic cylinder 8 of the vertical injection molding machine shown in FIG. 4, and mainly comprises a screw mechanism comprising a screw shaft 22 and a female screw member 23, and a drive motor 24. And The screw shaft 22 is supported by a bearing 25 at a lower end thereof and is vertically erected on the upper platen 4. A positive screw member 23 is fixed to a fixing portion 9 a of the plate 9 of the injection unit 7 and the upper end of the screw shaft 22 is fixed. Is screwed into.

The two sets of identical screw mechanisms are
The nozzle 6 is provided symmetrically with respect to the center of the nozzle 6, and its rotational resistance is large enough to support the load of the injection unit 7. In order to satisfy the above self-sustaining condition, the screw shaft 22 and the female screw member 23 are usually trapezoidal screws having a thread angle of 30 degrees.
A triangular screw of about 0 degree may be used.

A chain wheel 27 is fixed to the lower part of each screw shaft 22, respectively.
An endless chain 31 is wound around the drive wheel 7 and idle wheels 29 and 30 of the drive motor 7 and the drive motor 24. The drive motor 24 is attached to a base member 32 fixed to the upper panel 4, the idle wheel 29 is rotatably attached to the base member 32, and the other idle wheel 30 is attached to the base member 32.
It is rotatably attached to an adjusting member 33 which is movably provided.

The idle wheel 30 includes an adjustment bolt 34
The position can be adjusted in the left-right direction in FIG. 2 by the movement of the adjusting member 33 by the right side so that the chain 31 is not obstructed from the operation side (the left side in FIG. 2) of the vertical injection molding machine. Has been retreated. Reference numeral 35 denotes the screw shaft 2
2 is a cover cylinder that covers the upper portion of the second and is attached to the female screw member 23. The other structure is the same as that of the vertical injection molding machine shown in FIG.

Next, the operation of the vertical injection molding machine having the above configuration will be described. When the drive motor 24 is operated, the chain 31
, Each screw shaft 22 is rotated, so that each female screw member 2
3 moves up or down according to the rotation direction of each screw shaft 22, and raises or lowers the injection unit 7. When the drive motor 24 is stopped, the screw shaft 22 and the female screw member 23 satisfy the self-sustaining condition of the screw as described above, so that the screw shaft 22 does not rotate by the load of the injection unit 7 without permission. Therefore, the injection unit 7 does not descend naturally by its own weight, and keeps the state as it is.

When the nozzle 6 is pressed against the mold 3 and the molten resin is injected from the nozzle 6 into the molding cavity, the drive motor 24 is operated to lower the injection unit 7.
At the final stage, the detection switch 12 is operated by the stopper 11 also serving as a dog, and outputs a detection signal. The lowering speed of the injection unit 7 is reduced by this output signal. Immediately after that, the contact unit 9 b of the injection unit 7 is brought into contact with each stopper 11, and the injection unit 7 is pressed with the nozzle 6 against the mold 3. Stops. The injection process starts in this contact state.

In this vertical injection molding machine, since the stopper 11 also serves as the dog of the detection switch 12, there is no need to provide the dog as a separate member, and the structure is simplified accordingly. In the case where the nozzle 6 is replaced with a nozzle 6 having a different length, it is only necessary to adjust the position of the stopper 11 in accordance with the nozzle length, so that the nozzle can be easily and quickly replaced.

The position of the stopper 11 may be adjusted, for example, by forming the through hole 16a of the bracket 16 into a vertically long hole and adjusting the position within the length of the nozzle.
The bracket 16 or the stopper 11 having a length corresponding to the length of the nozzle 6 may be prepared in advance, and when the nozzle 6 is replaced, the bracket 16 or the stopper 11 may be replaced together.

The detection switch 12 shown in the figure is attached to the injection unit 7, but in some cases, the detection switch 1
2 may be attached to the stopper 11 so that the contact portion 9a of the injection unit 7 (including the periphery of the contact portion 9a) also serves as a dog. As the detection switch 12, a limit switch, a proximity switch, or the like is generally used.

Further, in the case of the moving device 21 shown in the figure, since no hydraulic oil is used, no trouble occurs due to oil leakage. However, the stopping device of the present invention includes, as a moving device, a vertical injection molding machine using a hydraulic cylinder 8 as shown in FIG. 4, a vertical injection molding machine using a screw mechanism that does not satisfy the self-standing condition, and a female screw member. The present invention can also be applied to a vertical injection molding machine using a rotating screw mechanism, or other types such as a horizontal injection molding machine.

The detection signal from the detection switch 12 is used not only to control the moving device 21 to reduce the moving speed of the injection unit 7 but also as a nozzle touch confirmation signal (injection start signal).

[0025]

As described above, according to the first aspect of the present invention, the nozzle of the injection unit is brought into contact with the mold by bringing the contact portion of the injection unit into contact with the moving unit when the injection unit approaches the mold. The injection molding machine includes a stopper that stops the injection unit in a state of being pressed, and a detection switch that is actuated by a dog immediately before the contact portion of the injection unit comes into contact with the stopper to detect the approach movement of the injection unit. In the injection unit stopping device, the detection switch is attached to one of the stopper and the injection unit, and the other of the stopper and the injection unit is also used as the dog. There is no need to separately provide the member, and the dog and the parts necessary for attaching the dog can be reduced, so that the structure is simplified. Further, when the nozzle is replaced with a nozzle having a different length, it is only necessary to adjust the position of the stopper, so that no trouble and time are required, and the nozzle replacement can be accurately dealt with.

In the above-mentioned stopping device, if the stopper is configured to be detachably mounted on a mounting plate on which a mold is mounted by a bracket, several types of brackets suitable for the length of the nozzle are prepared in advance. This makes it possible to easily adjust the position of the stopper.

If the stopper is constituted by a pair of semi-circular members, and the pair of semi-circular members is fitted in a ring shape on a guide rod for guiding the injection unit, the fixing strength of the stopper is improved. Can be increased.

According to a fourth aspect of the present invention, in the vertical injection molding machine having the above-described stopping device, the moving mechanism is configured to use a screw mechanism. There is an effect that defects of a vertical injection molding machine using a cylinder as a moving device can be completely eliminated.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a side view partially broken away.

FIG. 3 is a diagram illustrating an example of mounting a stopper.

FIG. 4 is a front view of a conventional vertical injection molding machine.

[Explanation of symbols]

 Reference Signs List 3 Mold 6 Nozzle 7 Injection unit 9b Contact part 11 Stopper (dog) 11a Semicircular member 11b Upper semicircular member 12 Detection switch 14 Guide rod 16 Bracket 21 Moving device 22 Screw part 23 Female thread part 24 Drive motor 31 Chain

Claims (4)

(57) [Claims] A stopper for stopping the injection unit in a state in which the nozzle of the injection unit is pressed against the mold when the injection unit approaches the mold by the moving device; A detection switch which is actuated by a dog immediately before the contact portion of the unit comes into contact with the stopper to detect the approaching movement of the injection unit. A stopper for the injection unit in the injection molding machine, wherein the stopper is attached to one of the injection unit and the other of the stopper and the injection unit is also used for the dog. 2. A device for stopping an injection unit in an injection molding machine according to claim 1, wherein the stopper is removably mounted on a mounting plate on which a mold is mounted by a bracket. 3. The stopper according to claim 1, wherein the stopper comprises a pair of semi-circular members, and the pair of semi-circular members are annularly fitted to a guide rod for guiding the injection unit. Or a stop device for an injection unit in the injection molding machine according to 2. 4. A vertical injection molding machine equipped with the stopping device according to claim 1, wherein a screw mechanism is used for the moving device.