JPH05253989A - Vertical injection molding machine - Google Patents

Abstract

PURPOSE:To prevent overtravel at the time of adjusting of a die height since this is a vertical injection molding machine provided with a link type mold clamping mechanism. CONSTITUTION:This is an injection molding machine 1 provided with a vertical mold clamping unit 2, the mold clamping unit 2 is fixed to a base 20 by a central ejector platen 5, a die height adjusting mechanism 11 is provided between a lower die height platen 6 and tie bar 7 and an over travel detection mechanism 18 comprising a dog 16 and limit switch 17 is provided between the die height platen 6 and tie bar 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical injection molding machine equipped with a vertical mold clamping unit.

[0002]

2. Description of the Related Art A mold clamping unit of a vertical injection molding machine includes an upper movable platen, an intermediate protruding platen, a lower die height platen, a tie bar, and a mold clamping mechanism.
In these, a movable platen and a die height platen are connected by a tie bar, and a protruding platen is vertically movably fitted into the tie bar and is connected to the die height platen by a mold clamping mechanism. The mold clamping unit thus configured is attached to the base by fixing the protruding platen to the base.

In the mold opening / closing operation of the mold clamping unit, the die height platen is moved up and down with respect to the projecting platen by the mold clamping mechanism, whereby the movable platen is moved up and down through the tie bar and between the projecting platen. The mold is opened and closed. The range of vertical movement depends on the die height of the mold.

The die height can be adjusted by adjusting the amount of rotation of a servo motor that drives the mold clamping mechanism when the mold clamping mechanism is a direct-acting type. The direct-acting mold clamping mechanism has a structure in which a ball screw / nut mechanism is driven by a servomotor and the linear movement thereof is directly transmitted to the die height platen.

In the case of a link type such as a toggle or a crank, the expansion and contraction strokes are constant, so by changing the distance between the movable platen and the die height platen,
The spacing between the movable platen and the protruding platen is adjusted. In the link type mold clamping mechanism, when the distance between the movable platen and the die height platen is changed as described above, the tie bar is vertically inserted into and removed from the die height platen. For this reason, it is necessary to provide an overtravel detection mechanism so that the tie bar will not be pulled out of the die height platen or pulled too far.

The overtravel detection mechanism is a base on which the rear platen corresponding to the die height platen and the mold clamping unit are placed when the mold clamping unit having the link type mold clamping mechanism is a normal horizontal type. However, if the mold clamping unit is a vertical type, the die height platen moves up and down with respect to the base each time the mold is opened and closed, so overtravel between the base and the die height platen as before. No detection mechanism can be provided.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vertical injection molding machine equipped with a link type mold clamping mechanism and capable of detecting overtravel during die height adjustment.

[0008]

The present invention relates to an injection molding machine equipped with a vertical mold clamping unit. The mold clamping unit includes an upper movable platen, an intermediate protruding platen, a lower die height platen, a tie bar, and a link type mold clamping mechanism. The movable platen and the die height platen are coupled by a tie bar, and the protruding platen is vertically movably fitted into the tie bar and coupled to the die height platen by a mold clamping mechanism.

The mold clamping unit is attached to the base by fixing the protruding platen to the base. A die height adjusting mechanism is provided between the die height platen and the tie bar. Between the die height platen and the tie bar, an overtravel detection mechanism with a dog and limit switch is installed.

[0010]

The overtravel detection mechanism using the dog and the limit switch detects the limit position where the tie bar is inserted into and removed from the die height platen in the die height adjustment.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vertical injection molding machine 1 shown includes a vertical mold clamping unit 2 and a parting line injection type injection unit 3.
It is configured by connecting. Vertical type clamping unit 2
As shown in FIG. 2, the upper movable platen 4, the middle protruding platen 5, the lower die height platen 6, the four tie bars 7, and the link type mold clamping mechanism include a mold clamping mechanism 8 by a double toggle.

The movable platen 4 and the die height platen 6 are connected by a tie bar 7, and the protruding platen 5 is fitted in the tie bar 7 so as to be vertically movable. The die height platen 6 and the protruding platen 5 are connected by a mold clamping mechanism 8. The mold clamping mechanism 8 is driven by vertically moving a crosshead 9 connecting the middles of both links with a mold clamping servomotor 10 attached to the die height platen 6.

A die height adjusting mechanism 11 is provided between the die height platen 6 and the tie bar 7. The die height adjusting mechanism 11 includes a feed screw portion 12 formed at the bottom of each tie bar 7 and a tie bar nut 1 having an outer periphery formed as a sprocket.
3, a chain 14 and a die height adjusting motor 15 are provided. The screw pitch of the feed screw portion 12 is formed to be relatively small.

Each tie bar 7 is fitted into the die height platen 7 and slidable up and down.
Reference numeral 3 denotes a position where the tie bar 7 is inserted and is pivotally attached to the lower surface of the die height platen 6 and is rotatable at a fixed position. The die height adjusting motor 15 is attached to the die height platen 6. These are tie bars 7
Screwing the feed screw part 12 to the tie bar nut 13 to connect the movable platen 4 and the die height platen 6 and then
A series of chains 14 are wound around the sprockets of each tie bar nut 13, and this chain 14 is assembled so as to be driven by a die height adjusting motor 15.

A dog 16 is fixed to the end of one tie bar 7, and two limit switches 17a and 17b are attached to one side of the die height platen 6 to form an overtravel detecting mechanism 18. Has been done. The acting portion 19 of the dog 16 is located in the middle of the limit switches 17a and 17b, and when there is relative movement between them, the dog 16 causes the limit switches 17a and 1b to move.
7b is activated. The upper limit switch 17a is arranged in the pull-out limit position of the tie bar 7, and the lower limit switch 17b is arranged in the pull-in limit position of the tie bar 7.

The mold clamping unit 2 configured as described above
Is attached to the base 20 by fixing the central projecting platen 5 to the base 20. Further, the vertical injection molding machine 1 is controlled by a numerical controller (NC device) like the conventional one, and the driving of the mold clamping servomotor 10 and the die height adjusting motor 15 is under the control thereof. The on / off signals from the limit switches 17a and 17b are treated as control data. Further, the die height adjusting motor 15 can be manually inched from the operation panel of the mold clamping unit 2 as in the conventional case.

Since the other components such as the injection unit 3 are not different from those of the conventional vertical injection molding machine, detailed description thereof will be omitted. In the injection molding process,
The mold clamping mechanism 8 is driven when the mold clamping servomotor 10 is driven.
The mold is opened and closed via the resin, and during that time, the resin is injected from the injection unit 3 into the mold to hold the pressure, cool it, and take out the molded product. When the molding by one mold is completed, the mold is replaced. At that time, the die height adjustment for adjusting the vertical position of the movable platen 4 according to the die height dimension of the die is performed as follows.

When the NC device is in the die height adjustment mode and the start button is pressed after the old mold is taken out, first, the data regarding the new mold is read from the memory into the processor. Then, the mold clamping servomotor 10 is driven and the crosshead 9 of the mold clamping mechanism 8 is moved to a position corresponding to a mold touch for a new mold and stopped. The toggle of the mold clamping mechanism 8 is in a state of being contracted from the maximum extension position by the amount of driving for lockup.

Next, the die height adjusting motor 15 is driven to feed each tie bar 7 to the maximum extraction position via the tie bar nut 13 and the feed screw portion 12. The maximum extraction position is preset by a limit switch or the like. A new die is placed on the ejection platen 5, and the lower die is fixed to the ejection platen 5. NC
When the operator presses the continue button according to the instruction from the device,
The die height adjusting motor 15 is driven in the opposite direction, and each tie bar 7 is pulled in until the lower surface of the movable platen 4 contacts a new mold.

When the movable platen 4 comes into contact with the mold, the torque of the die height adjusting motor 15 rapidly increases.
When this is detected, the NC device stops the die height adjusting motor 15. This completes the die height adjustment and cancels the die height adjustment mode of the NC device.
The die height adjusting position, that is, the stop position of the tie bar nut 13 is maintained by a slight torque of the die height adjusting motor 15 because the screw pitch of the feed screw portion 12 is small.

When the tie bar 7 is pulled out from the die height platen 6 and the tie bar 7 is pulled out more than the limit due to an unexpected reason, the operating portion 19 of the dog 16 operates the upper limit switch 17a. Then, the driving of the die height adjusting motor 15 is forcibly stopped.
On the contrary, when the tie bar 7 is about to be retracted beyond the limit with respect to the die height platen 6, the dog 16 operates the lower limit switch 17b, and the die height adjusting motor 15 is forcibly stopped also at this time.

The detection of the limit position for this forced stop is made by a limit switch and a dog, and the structure is simple and reliable.

The above is an embodiment. The mold clamping mechanism 8 may be another link type single toggle or crank type. The die height adjusting motor 15 may be manually driven from the operation panel of the mold clamping unit 2. The die height adjusting mechanism may be constructed hydraulically.

[0024]

EFFECTS OF THE INVENTION In a vertical injection molding machine in which a vertical type mold clamping unit employs a link type mold clamping mechanism, overtravel during die height adjustment is reliably prevented with a simple structure. ..

[Brief description of drawings]

FIG. 1 is a front view showing an outline of a vertical mold clamping unit.

FIG. 2 is a schematic front view of a vertical injection molding device.

[Explanation of symbols]

1 injection molding machine 2 mold clamping unit 3 injection unit 4 movable platen 5 protruding platen 6 die height platen 7 tie bar 8 mold clamping mechanism 11 die height adjusting mechanism 12 feed screw section 15 die height adjusting motor 16 dog 17 limit switch 18 overtravel detection mechanism

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29C 45/84 7365-4F

Claims (1)

[Claims] 1. An injection molding machine comprising a vertical mold clamping unit, wherein the mold clamping unit comprises an upper movable platen, an intermediate ejecting platen, a lower die height platen, a tie bar and a link type mold clamping mechanism. The movable platen and the die height platen are connected by a tie bar, the protruding platen is inserted in the tie bar so that it can move up and down, and is connected with the die height platen by a mold clamping mechanism, and this mold clamping unit has the protruding platen fixed to the base. The vertical injection molding is characterized in that it is attached to the base by a die height adjusting mechanism between the die height platen and the tie bar, and an overtravel detecting mechanism by a dog and limit switch is provided between the die height platen and the tie bar. Machine.