JPH0339224Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a toggle type mold clamping device with a fixed adjustment nut in an injection molding machine.

(Prior art) Modern injection molding machines produce high-quality molded products at high cycles, so the accuracy of molding molds as well as
The injection molding machine itself also requires high mold clamping accuracy.

Generally, in a toggle type mold clamping device, as shown in FIG. 3, a fixed plate 1' and a toggle support 8' are connected by a tie rod 3', and a movable plate 4 is slidably fitted into the tie rod 3'. ' to the mold clamping cylinder 1 via the toggle lever 7' and toggle pin 6'.
3', and is configured to move the movable plate 4' forward and backward toward the fixed plate 1'.

(Problems to be Solved by the Invention) However, in the conventional toggle type mold clamping device, when adjusting the mold clamping force or changing the thickness of the mold, the adjustment nut 10' screwed onto the tie rod 3' must be adjusted. This is done by moving the toggle support 8' forward or backward by rotating the adjustment gear 11', so when the toggle support 8' is moved forward (by rotating the adjustment gear 11' clockwise), the adjustment nut 10'
Since the toggle support 8' and the toggle support 8' come into contact with each other, the clearance B shown in FIG. 4 disappears, but the clearance C between the adjusting nut 10' and the tie rod 3' occurs.

On the other hand, move the toggle support 8' backward (adjustment gear 1
1' counterclockwise), the nut holder 9' and the nut 10' come into contact, so a clearance B shown in Fig. 4 is created, and the clearance between the adjusting nut 10' and the tie rod 3' disappears. However, there are four tie rods 3', and due to component precision, assembly errors, etc., they may not all act in the same way.

That is, when no mold clamping force is applied, the toggle support can move by the clearances B and C, resulting in adjustment errors and problems such as difficulty in maintaining parallelism between the fixed plate and the movable plate.

(Solution by Invention) This invention attaches a lock cylinder to the toggle support via a bracket, and presses the end face of the tie rod with the piston rod of the lock cylinder, thereby crimping the adjustment nut to the toggle support and tightening the adjustment nut and tie rod. The toggle support and the tie rod can be held in the same state even when no mold clamping force is applied by eliminating the clearance generated in the threaded part between them.

(Example) An explanation will be given with reference to FIGS. 1 and 2. FIG. 1 shows a toggle type mold clamping device to which the present invention is applied.

1 is a fixing plate, and one end of a tie rod 3 is fixed to the plate 1 with a fixing nut 2. A movable plate 4 is slidably fitted to the tie rod 3 via a bush 5. The fixed plate 1 of this movable plate 4
A toggle lever 7 is pivotally mounted on the opposite side via a toggle pin 6. 8 is a toggle support, to which a toggle lever 7 is pivotally attached via a toggle pin 6, and a mold clamping cylinder 13 is attached, and the toggle lever 7 is extended and contracted by the back and forth movement of the cylinder 13, and the movable plate Slide 4.

Reference numeral 10 denotes an adjustment nut, which is held on the opposite side of the toggle support 8 by a nut holder 9, and the other end of a tie rod is screwed into the nut 10.

Reference numeral 11 denotes an adjustment gear, which is fixed to the adjustment nut 10, and when adjusting the mold clamping force or changing the thickness of the mold, the four adjustment gears 11 are rotated by an idling gear 12 meshing with the adjustment gear 11. to adjust the position of the toggle support 8. That is, for example, in order to reduce the mold mounting thickness, the adjustment gear 11 is rotated clockwise to press the end face of the toggle support 8 via the adjustment nut 10, thereby moving the toggle support 8 forward.

14 is an L-shaped bracket fixed to the toggle support 8, and the tie rod 3 of this bracket 14 is fixed to the toggle support 8.
A lock cylinder 15 is attached to the surface facing the tie rod 3, and when the piston rod 16 of the lock cylinder 15 is extended, it presses against the end surface of the tie rod 3. 17 is a pressure oil inlet/outlet.
Molding molds 18 and 19 are mounted on the fixed plate 1 and the movable plate 4, respectively.

(Function) When adjusting the position of the toggle support 8 when replacing the molding molds 18 and 19 or adjusting the mold clamping force, the pressure oil inlet/outlet 17 of the lock cylinder 15 attached to the toggle support 8 via the bracket 14 is illustrated. When hydraulic pressure is supplied from a hydraulic control device that does not operate, the piston rod 16 expands and presses the end face of the tie rod 3.

In this state, when the adjusting nut 10 is rotated clockwise, the adjusting nut 10 pushes the end face of the toggle support 8 and moves it forward, as shown in FIG. However, since the lock cylinder 15 is pushing the end face of the tie rod 3, the clearance B between the toggle support 8 and the adjustment nut 10 and the clearance C between the screw of the adjustment nut 10 and the threaded part of the tie rod 3 disappear, and the toggle support 8 is pushed against the tie rod 3. The screws of the toggle support 8 and tie rod 3 are fixed without any gaps, and the positional relationship between the screws of the toggle support 8 and the tie rod 3 does not change between when the mold clamping force is generated and when the mold clamping force is released (the mold opens).

(Effects) According to the present invention, by pressing the head of the tie rod 3 with the piston rod 16 of the lock cylinder 15, the adjustment nut 10 and the toggle support 8
The clearance B between the screws of the adjustment nut 10 and the screws of the tie rod 3 are eliminated, and the toggle support 8 and tie rod 3 are fixed without any gaps, the position of the movable plate 4 is stabilized, and the parallelism is improved. It became possible to improve accuracy.

In this way, the clearance between various parts that occurs due to the large number of parts in a toggle type mold clamping device is eliminated, and a mold clamping device with extremely high precision can be obtained.

[Brief explanation of drawings]

Figure 1 shows a mold clamping device incorporating the present invention. FIG. 2 is a state diagram when the mold clamping force is released in the mold clamping device according to the present invention. Figure 3 shows a conventional mold clamping device. FIG. 4 shows a state diagram of the engagement portions of the toggle support, nut holder, and tie rod when the mold clamping force is released in the conventional mold clamping device. In the figure: 1... fixed plate, 2... fixed nut, 3... tie rod, 4... movable plate, 5... bush, 6... toggle pin, 7... toggle lever, 8... toggle support, 9... ...nut presser,
10...Adjusting nut, 11...Adjusting gear, 12...
...Idle gear, 13...Mold clamping cylinder, 1
4...Bracket, 15...Lock cylinder, 1
6...Piston rod, 17...Pressure oil inlet/outlet, 1
8, 19...Molding mold.

Claims (1)

[Scope of utility model registration request] By attaching the lock cylinder 15 to the toggle support 8 via the bracket 14 and pressing the end face of the tie rod 3 with the piston rod 16 of the lock cylinder, the adjustment nut 1 is attached to the toggle support 8.
A toggle-type mold clamping device with a fixed adjustment nut, characterized in that it crimps the adjustment nut 10 and eliminates the clearance that occurs between the adjustment nut 10 and the threaded portion of the tie rod 3.