JPS60264220A - Adjusting device of clamping force - Google Patents

Abstract

PURPOSE:To obtain a clamping device through which the optimum clamping force is obtained automatically without relying upon human power, by providing a control device positioning a rear platen at an appropriate position by driving a first servomotor by a necessary control quantity. CONSTITUTION:The position of a rear platent 6 corresponding to a thickness of a mold is obtained by a CPU28 through a table of a memory 30, a first servomotor 18 is made to drive, which is made to drive until a value read from the table becomes coincident with that of a first position counter 26 and the rear platen 6 is moved up to that position. When a quantity of elongation of a tie bar 5 is short in a specified quantity, a shortage amount in the quantity of elongation is calculated by the counter 26, the rear platen 6 is moved forward by the shortage amount by driving the servomotor 18 along with opening of molds 1, 3 by driving a second servomotor 24 and when the quantity of elongation arrives at the specified quantity, control of clamping force is completed. As the position of the rear platen can be controlled automatically according to a thickness of the mold, the constant elongation is obtained always even if the mold is changed and clamping can be performed by the optimum pressure for molding.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mold clamping force adjusting device for an injection molding machine having a toggle type mold clamping device.

Conventional technology Conventionally, toggle type mold clamping devices are used when replacing molds.
The mold thickness adjustment operation must be performed according to the thickness of the mold, and the operator should do it based on experience (I used two methods, but if the mold clamping nozzle is too strong, too much force will be applied to the tie bar and it will break. If it is too weak, injection molding cannot be done properly.

Problems to be Solved by the Invention Therefore, in view of the above-mentioned points, the present invention seeks to provide a mold clamping nozzle device that can automatically apply an optimum mold clamping force of 1q without relying on human hands when replacing a mold. It is something to do.

Means and Effects for Solving the Problems Fig. 1 is a block diagram of the main parts of the present invention.The present invention is an injection molding machine having a mold clamping device of 1-1 type, in which the rare platen D is placed on the rare platen D along a tie bar. a first servo motor B that moves the tie bar; a first position detection means F that detects the amount of extension of the tie bar; a second servo motor C that bends and extends the toggle mechanism F; A second position detecting means G for detecting the state is provided, and when one of the position data from the first position detecting means F and the second position detecting means G reaches a predetermined amount, the other A control means A is provided for determining a necessary adjustment amount from the position data, and driving the first servo motor by the necessary adjustment amount to position the rare platen at an appropriate position, thereby automatically matching the mold thickness of the mold. It is possible to determine the position of the rare platen where an appropriate mold clamping force can be obtained.

Embodiment FIG. 2 shows an embodiment of the present invention, in which a first mold 1 is mounted on a fixed platen 2, and a second mold 3 is mounted on a movable platen 4. The fixed platen 2 is provided at one end of the tie bar 5, a rare platen 6 is provided at the other end of the tie bar 5, and two sets of toggle links 7.8 are provided between the rare platen 6 and the movable platen 4.
A toggle mechanism consisting of the following is provided, and the movable platen 4 is driven by the toggle mechanism and is provided so as to be able to slide on the tie bar 5.

A through hole 9 is opened in the center of the rare platen 6, a first nut 10 is provided in the through hole 9, and the first nut 10 has a cross head for bending and stretching two sets of 1 to 1-glu links 7.8. A ball screw 12 to which 11 is connected is screwed together. The first nut 10 is fixed to the first gear 13 so that it can rotate together with the first gear 13.

A second nut 15 is provided on the back surface of the rare platen 6 to be screwed into each tie bar 5, and a sprocket 16 is provided 41i on the second nut. I is fixed to the rear platen 6 via 17.
, : By driving the first servo motor 18, the first one
The sprocket 1 installed on the shaft of the novo motor 18
~19. Chain 20. The second nut 15 is rotated through the sprocket 1 via the sprocket 1. One side surface of each nut 15 is formed into a flange shape, and this flange-like protrusion 14 engages with a groove 1/1' provided in the rare platen.
When the servo motor 18 is driven, each nut 15 rotates and moves on the tie bar 5 from side to side in FIG.
iK of the flange-like protrusion 14 of the rear platen 6 14
When each nut moves due to the engagement of ', the rare platen 6 also moves.

Furthermore, a first position detection device 21 is provided on the lower surface of the rare platen 6 to detect the amount of extension of the tie bar 5 based on the position of the rare platen 5-6.

Further, on the back side of the rare platen 6, the first gear 13 is provided.
A second servo motor 24 is provided which drives a second gear 22 meshing with the second gear via a shaft 23 . The second servo motors 24 are each provided with a second position detection device 25 for detecting the bending/extending state of the toggle mechanism.

The first position detecting device 21 is a first position counter 26, and the second position detecting device 25 is a second position counter 27. Each detection signal is counted and the current position is stored. The memory 30 is provided with a control program for overall control and a table in which the position of the rare platen 6 is stored in advance according to the mold thickness of the mold. Note that 33 is a printer.

Next, the operation of the above embodiment will be explained with reference to the operation flow shown in FIG.

First, to adjust for a new mold, enter the mold thickness of molds 1 and 3 from the operation panel 29, press the mold thickness automatic adjustment start button, and the CPU 28 will adjust the 6-rare platen 6 that matches the mold thickness. The position is read from the table in the memory 30, the first servo motor 18 is driven until the value read from the table matches the value of the first position counter 26, and the rare platen 6 is not moved to that position.

Next, the CPU 28 performs the processing from step 81 in FIG. 3 onwards. First, rotate the second servo motor 24, and rotate the motor shaft 23. Second gear 22. First gear 13. The ball screw 12 is rotated through the first nuts 1 to 10 to extend the toggle link 7.8, and the molds 1 and 3 are started to be tightened at a low speed (step S1). At this time, the counter 27 from the second position detects whether or not the mold 1 to glu link 7.8 is fully extended or not (Step S2). If it is not fully extended, the first position counter 26 detects the mold 1. It is necessary to judge whether the rare platen 6 has moved by a specified amount from the position when . In step S3), if the predetermined amount has not been reached, the processes from step 81 onwards are repeated again to continue driving the second screwdriver motor 24.

In step S3, when the elongation of the tie bar 5 reaches a specified amount, the rotation of the second servo motor 24 is stopped so as not to put an excessive load on the tie bar 5. In step S4), the second position counter 27 Based on the position data, the CPU 28 calculates the amount remaining until the Guru Link 7.8 is fully extended.Step s5)
Open the molds 1 and 3 by rotating the servo motor 24 in the opposite direction (
At the same time as step 86), the first servo motor 18 is driven to move the rare platen 6 backward by the remaining amount until the toggle link 7.8 is fully extended (step S7),
The process from step 81 onwards is repeated again. Step S2
If the toggle links 7 and 8 are completely extended by the second position counter 27, the rotation of the second servo motor 24 is stopped (step S8), and the tie bar is adjusted according to the position data of the first position counter 26. The CPU 28 determines whether the amount of elongation at step 5 has reached the specified amount (step S9), and if it is insufficient to the specified amount, calculates the shortfall in the amount of elongation from the first position J counter 26 (step 510).
), the second servo motor 24 is driven to open the molds 1 and 3 (step 511), and the first servo motor 18 is driven to move the rare platen 6 forward by the amount of shortage (step 512), step $ Return to 1.

In step S9, when the amount of elongation of the tie bars 5 is the specified amount, the adjustment of the mold clamping force is completed, and the position of the rare platen 6 at this time is printed and recorded by the printer 33 along with the name of the mold, etc.

Next, to use this mold for the second time or later, press the operation panel 29.
Then, input the position of the rare platen 6 recorded above, press the mold thickness automatic adjustment start button, and perform the mold clamping force adjustment process from step 81 as in the first time. This is to correct errors when fixing the molds 1 and 3 to the fixed platen 2 and the movable platen 4. In addition, in the above embodiment, the mold 1,
By storing the position of the standard rare platen 6 corresponding to the mold thickness in the memory 30 in advance and inputting the mold thickness from the operation panel 29, the position of the standard rare platen 6 according to the standard mold thickness stored in the memory 3o can be changed. However, the position of the standard rare platen 6 corresponding to the mold thickness is stored in the memory 3o, and the mold 1,
When the mold thickness automatic adjustment start button is pressed with 3 open, the first position counter 26 is reset from 1 to 1 by a signal from the CPU 28, and the process from step 81 in FIG. 3 is performed. Good too. In this case, the value of the first position counter is the extension/opening of the tie bar 5, and even if the toggle mechanism is fully extended, if the value of the first position counter is rOJ, the rare platen 6 is advanced by a certain amount (second (right side of the figure).

Effects As described above, the present invention can automatically adjust the position of the rare platen, which is the first platen of the toggle mechanism, according to the thickness of the mold, so that the amount of elongation of the tie bar is less than the specified amount. There is no risk of the mold being insufficiently tightened or the tie bar being overstretched and damaged, and even if the mold is replaced, the tie bar will always maintain a constant elongation, and the elastic recovery force of the tie bar will be improved by 10- This allows the mold to be tightened with the optimum pressure for molding, making it possible to perform injection molding with high accuracy and efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a diagram showing an embodiment of the invention, and FIG. 3 is a flowchart of the same embodiment. 5... Tie bar, 1.3... Mold, 2... Fixed plate, 4... Movable plate, 6... Rare platen, 18...
First servo motor, 21... first position detection device,
24... Second servo motor, 25... Second position detection device, 7.8... Toggle link, 10... First
12...Ball screw, 13...First gear, 15...Second nuts 1-. 16...1st
sprocket, 19...second sprocket, 20
...Chain, 22...Second gear. Patent applicant Fanuc Co., Ltd. Agent Patent attorney Tsukasa Takemoto Matsu (and 1 other person) 11- Figure 1

Claims (3)

[Claims] (1) In an injection molding machine with a toggle type mold clamping device,
a first servo motor that moves the rare platen along the tie bar on the rare platen; a first position detection means that detects the amount of extension of the tie bar from the position of the rare platen; and a second servo motor that bends and stretches the toggle mechanism. , a second position detection means for detecting a bending/stretching state of the toggle mechanism, and when either one of the position data from the first position detection means or the second position detection means reaches a predetermined amount. 1. A mold clamping force adjusting device comprising: a control means for driving said first servo motor based on position data of the other side at a time, and positioning said rare platen at an appropriate position. (2) A storage means for storing the position of a standard rare platen according to the mold thickness of the mold and a mold thickness input means are provided, and by inputting the mold thickness from the mold thickness input means, the control means reads the position of the storage means J and the relay platen;
The position read by driving the first 1-pubo motor/
\The mold clamping force adjusting device according to claim 1, which moves the rare platen. (3) A printer is provided, and after the control means determines the proper position of the rare platen according to the mold by 1 meter, the printer stores the mold name and the proper rare platen position. The mold clamping force adjusting device according to item 1 or 2.