JPS5949903B2 - Toggle type mold clamping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a trouble mold clamping device used in a molding machine such as a die casting machine or an injection molding machine. This invention relates to a mold clamping device that can detect before the end of clamping.

Generally, in die casting machines and injection molding machines, it is necessary to apply a desired mold clamping force when clamping the mold.

If this mold clamping force is larger than the set value, there is a risk of overloading the machine and damage to the equipment, while if the mold clamping force is small, molten metal may spout from the mold surface, etc. Accidents occur.

Particularly in large machines that exceed 1000 tons, excessive or insufficient mold clamping force as described above can lead to serious accidents.

Therefore, various methods for detecting mold clamping force have been proposed.

One method is to measure the elongation of tie bars during mold clamping.

In a mold clamping device that employs a trouble mechanism, which is a boosting mechanism, a large mold clamping force is applied during mold clamping, and the tie bars, which have a diameter of 200 to 300 mm, are also extended by several mm.

Since this elongation is proportional to the mold clamping force, the mold clamping force can be determined by measuring the amount of elongation.

However, when such a method is adopted, the mold clamping force is detected with an elongation of only a few degrees, which inevitably results in detection errors and poor measurement accuracy.

Another method has been proposed in which a hole is made in one end of the tie bar and a strain gauge is installed in the hole to measure the stress during mold clamping and the clamping force. When using this method, there is a disadvantage that the strength is partially reduced because holes are made in the tie bars.

In addition, since the mold clamping force is measured by measuring the partial elongation,
This also has poor accuracy.

Furthermore, there is a method of detecting the tightening force by measuring the driving distance of the nut provided on the tie bar, but this method also has the disadvantage of poor accuracy because the driving distance is small.

In addition, as mentioned above, in the method of measuring the mold clamping force by measuring the elongation of the tie bars and the stress generated in the tie bars, after the movable mold contacts the fixed mold during the mold clamping operation, the movable mold It is impossible to know whether a normal mold clamping force has been obtained until the final mold clamping force is obtained by advancing the mold several times further and finally obtaining a mold clamping force close to the prescribed mold clamping force. could not.

In other words, even if the mold clamping force at the end of mold clamping is greater than necessary, it is known that the mold clamping force is excessive unless the piston rod of the mold clamping cylinder reaches its forward limit at the end of mold clamping. I couldn't.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate these drawbacks and provide a trouble mold clamping device that can extremely easily detect whether the mold clamping force is normal before mold clamping is completed.

To this end, the present invention includes a piston rod remaining stroke detection device that detects whether the piston rod of the mold clamping cylinder has a predetermined remaining stroke when the movable mold contacts the fixed mold during the mold clamping operation. , consisting of a position detector such as two limit switches or a pulse transmitter, which are operated by the movement of a detection rod attached to the piston rod of the mold clamping cylinder, and which are arranged at a predetermined distance from each other, and the detection rod. It is possible to install the position detector at a predetermined position on a fixed part that is part of the movement locus of the detection rod and is integrated with the machine base, link housing, etc. of the trouble-forming clamping device.

A mold contact detection device is installed to detect when the movable mold contacts the fixed mold, and the mold contact detection device and the piston rod remaining stroke detection device operate to determine whether the mold clamping force is normal or excessive when the mold contacts. It is equipped with a control circuit that issues a signal of insufficient mold clamping force and a device that displays whether the mold clamping force is normal or abnormal.

It is a rubber molding and tightening device.

Hereinafter, the present invention will be described in detail together with embodiments shown in the drawings.

1 and 2 illustrate one embodiment of the present invention. In the figures, 1 is a fixed platen, , a fixed mold 2
is installed.

3 is a movable platen, to which a movable mold 4 is attached.

The movable platen 3 is equipped with a trouble mechanism 5 consisting of several link levers provided between the movable platen 3 and the link housing 14.
operated via.

Reference numeral 19 denotes four tie bars that are attached between the fixed platen 1 and the Linkz Ujifugu 14, passing through the movable platen 3.

A mold clamping cylinder 7 is attached to the link housing 14, and the inner link 6 of the trouble mechanism 5 is connected to a block 15 attached to the tip of the piston rod 8 of the mold clamping cylinder 7.

Reference numeral 16 denotes a guide rod for guiding the block 15, the tip of which is fixed to the movable platen 3, and extends rearward while penetrating the block 15 and the ring housing 14.

The trouble mechanism 5 having these structures is commonly used in trouble forming and tightening devices.

A detection rod 9 extends from the middle of the piston rod 8 or from a part of a block 15 fixed to the tip of the piston rod 8.
Position detectors such as limit switches A and B for the remaining stroke detection device 10 are disposed corresponding to the tip of the portion parallel to the position.

Of course, the detection rod 9, limit switches A, B, etc. are provided at positions where they do not interfere with the movement of the block 15 and the links of the dragle mechanism 5.

This remaining stroke detection device 10 detects when the movable mold 4 comes into contact with the fixed mold 2 during the mold clamping operation and begins to move the movable mold 4 further forward to obtain a predetermined mold clamping force. , to detect whether the piston rod 8 of the mold clamping cylinder 7 has a predetermined remaining stroke.

The remaining stroke detection device 10 consists of a position detector consisting of, for example, two limit switches A and B, and a detection rod 9 attached to a piston rod 8. They are arranged side by side with slight predetermined intervals.

The two limit switches A and B, which act as position detectors by movement of the detection rod 9 attached to the piston rod 8, are part of the movement locus of the detection rod 9 and are integrated with the machine base 17, link housing 14, etc. It is attached at a predetermined position on a fixed part such as a bracket 18 that is

Needless to say, the position detector is arranged at a predetermined position where, when the movable mold 4 comes into contact with the fixed mold 2, a portion of the detection rod 9, such as the rear end, on which the position detector acts comes. ing.

The two limit switches A and B are arranged with a small distance, for example 3 to 7 mm, in the mold opening direction, so they are placed slightly apart from each other in the lateral direction, as shown in Figures 1 and 2. It is also possible to use a structure in which the detection rod 9 is slightly wider in the lateral direction in accordance with the staggered arrangement.

It is desirable that the mounting positions of the limit switches A and B, which are position detectors, can be freely adjusted in the clamping mold opening direction.

As the position detector used in the remaining stroke detection device 10, a pulse transmitter, a differential transformer, or the like may be used instead of the two limit switches A and H.

When using a pulse transmitter as a position detector, the detection rod 9 should be equipped with a magnetic scale, and the detection rod 9 should be equipped with a magnetic scale.
The remaining stroke of the piston rod 8 is accurately detected based on the position.

Usually 1 mm using a magnetic scale and pulse transmitter
However, if the electrical signal output from the pulse transmitter is electrically processed, it can be read up to a minimum of 0.1 mm.
Alternatively, it is possible to read down to 0.011 tm.

On the other hand, a mold contact detection device 11 is provided on the head side of the mold clamping cylinder 7.

The mold contact detection device 11 uses, for example, a pressure switch to detect the back pressure of the mold clamping cylinder 7 and input this to the control circuit 12 as an electrical signal.

Further, a signal from the remaining stroke detection device 10 is also input to the control circuit 12.

The control circuit 12 detects whether the mold clamping force is normal or excessive or insufficient when the mold contacts, by the actions of the mold contact detection device 11 and the piston rod remaining stroke detection device 10.

The mold clamping force is determined to be normal according to the operation of the piston rod remaining stroke detection device 10 at the time when the mold contact detection device 11 operates and detects that the movable mold 4 has contacted the fixed mold 2. A signal is now issued to indicate whether the mold clamping force is excessive or insufficient.

Connected to the control circuit 12 is a mold clamping force normality/abnormality display device such as a lamp that indicates whether the mold clamping force is normal or excessive or insufficient when the mold contacts.

Next, the operation of this embodiment configured as above will be explained.

Generally, in a die casting machine or an injection molding machine that operates the trouble mechanism 5 to clamp the mold, the ratio between the stroke S of the clamping cylinder 7 and the elongation λ of the tie bar 19 during mold clamping is several tens to - If the amount of movement of the piston rod 8 or its position is detected, the extension of the tie bar can be expanded several tens of times and taken out.

The ratio of the forward distance of the piston rod 8 of the mold clamping cylinder 7 and the extension of the tie bar 19 near the end of mold clamping, such as when the movable mold 4 contacts the fixed mold 2 during the mold clamping operation, is:
This is naturally determined by the length of each link in the trouble mechanism 5, the rotational wear coefficient of the doggle pin 20 provided between each link, etc., and the ratio is approximately 20:1 for the trouble mechanism of any die-casting machine or injection molding machine. ing.

This ratio is determined both by actual measurements and calculations for each machine, and it is well known to those skilled in the art that it is approximately 20:1.

Trouble forming clamping equipment such as die casting machines, etc.
The piston rod 8 of the mold clamping cylinder 7 from when the movable mold 4 comes into contact with the fixed mold 2 during the mold clamping operation until the end of mold clamping.
The remaining stroke S and the output magnification n of the trouble mechanism 5 (the magnification of the mold clamping force T generated on the movable platen 4 with respect to the output F of the mold clamping cylinder 7) are proportional, and the mold clamping force T and the elongation of the tie bar 19 are proportional to each other. λ is proportional, and the relationship between the remaining stroke S of the piston rod 8 and the mold clamping force T is approximately a curve X as shown in FIG. 3 in any trouble mold clamping device.

Figure 3 shows the remaining stroke S (gi) of the piston rod 8 and the mold clamping force T (ton) when the mold clamping force is 1650 tons.
FIG. 4 is a diagram showing the relationship between the elongation λ(IIME) of the tie bar 19 and the elongation λ(IIME) of the tie bar 19.

In the trouble mold clamping device of the die casting machine shown in FIG.
It is designed to be 3.3 dragons.

In addition, if the setting is made so that the regular mold clamping force of 1650 tons is obtained at the end of mold clamping, the movable mold 4
The remaining stroke S of the piston rod 8 when the piston rod 8 contacts the fixed mold 2, that is, the stroke that indicates how far the piston rod 8 can move forward from that point is 140.
It is pre-designed to be 1m.

Generally, in mold clamping devices such as die casting machines and injection molding machines, a tolerance range of, for example, 5% is often given to the clamping force.

Of course, the remaining stroke S of the piston rod 8 when the movable mold 4 contacts the fixed mold 2 during the mold clamping operation is also given a certain allowable range.

Now, if the allowable range of mold clamping force is 5 inches, as shown in Figure 3, when the mold clamping force T is 1650 tons, the mold clamping force tolerance C is 1650 tons, which is 82.5 tons at 5% of n.
Therefore, the elongation of tie bar 19 is 3.3 The allowable error of the dragon is 3
．． 5 inches of 3mm is 0.165mm.

On the other hand, the ratio of the forward distance of the piston rod 8 to the elongation of the tie bar 19 near the end of mold clamping is 20:1, as described above.
Therefore, the forward distance of the piston rod 8 when the tie bar 19 is extended by 0.165 mm is 0.1651 mX.
20=3.3mm.

Therefore, the actual mold clamping force is the set mold clamping force of 1650 tons.
If the stroke of the piston rod 8 differs by 3.3 mm from the normal stroke, if the stroke differs by 82.5 tons, which is the allowable range of If it is confirmed that when the movable mold 4 contacts the fixed mold 2, the actual remaining stroke S of the piston rod 8 is only 3.3 m or less different from the normal remaining stroke S = 140 mm. It can be seen that the mold clamping force T at the end of mold clamping is within the desired tolerance range of 5 degrees.

The present invention is an application of such a principle, and when the movable mold 4 contacts the fixed mold 2, the remaining stroke detection device 10 is configured such that when the movable mold 4 contacts the fixed mold 2, the detection end of the detection rod 9 is connected to the two limit switches A and B. Adjust so that only the limit switch B closest to the mold side is turned on.

Of course, the installation positions of the two limit switches A and B should be adjusted in advance so that they are at predetermined positions with a predetermined distance determined according to the allowable range of the actual mold clamping force to the set mold clamping force. I'll keep it.

And like this, when limit switch A is OFF,
A logic circuit is constructed so that a signal is input to the control circuit 12 only when the limit switch B is ON.

As mentioned above, when the mold clamping force is 1650 tons, the permissible range of the mold clamping force is 5 parts, and the permissible range of the remaining stroke of the piston rod 8 at that time is 3.3 parts, so the difference between the two limit switches A and B is The installation interval depends on the type.

Considering both excess and deficiency of tightening force, 3.3iiX2
= 6.6 mw.

On the other hand, the movable mold 4 is moved by the mold clamping cylinder 1, but the driving pressure until the mold contacts is 15 to 20 kg/
It is as small as cri, and the mold clamping pressure after contact is 10 kg/c per page.
rj, which is extremely large, is immediately detected by the mold contact detection device 11, and a mold contact signal is input to the control circuit 12.

Then, only when this mold contact signal and the signal from the remaining stroke detection device 10 are input from the control circuit 12,
A signal indicating that the mold clamping force is normal is transmitted, a lamp is displayed, and the movable mold 4 continues to move forward.

In addition, if it is possible to know the remaining stroke of the mold clamping cylinder when the mold contacts occur, for example, as shown by the curve X in FIG. The relationship between the remaining stroke S and mold clamping force T is logically determined by the machine design, so it is important to know how much the mold clamping force T will be when the remaining stroke S is. I can do it.

Therefore, by adopting the above-mentioned structure, the relative position of the position detector of the remaining stroke detection device 10 and the detection rod 9 is adjusted so that the remaining stroke S of the mold clamping cylinder 7 is at an appropriate amount when the mold contacts. By setting the position, a signal indicating that the mold clamping force T is appropriate can be obtained.

Note that if a pulse transmitter is used as the remaining stroke detection device 10, the remaining stroke of the piston rod 8 can be detected even more accurately, and the mold clamping force T can be known more accurately.

Of course, a device for calculating and detecting the mold clamping force T from the remaining stroke of the piston rod 8 can be incorporated into the control circuit 12.

With this arrangement, the piston rod remaining stroke detector 10 operates when the mold contact detector 11 operates and detects that the movable mold 4 has contacted the fixed mold 2, and the piston rod 8 remains. Know the stroke,
From this amount, it is possible to know the mold clamping force at the time when the piston rod advances.

Furthermore, as described above, if a pulse transmitter is used, the remaining stroke of the piston rod 8 can be detected normally at a rate of 1, and furthermore, if the output signal is electrically processed, the remaining stroke of the piston rod 8 can be detected at a rate of 0. It can be easily detected in units of one battle or even at 0.01m74th.

Therefore, when the above mold clamping force is 1650 tons,
The error in the remaining stroke of piston rod 8 is 3.3 mm.
At this time, the error in the mold clamping force is 5 factors, so the detection of this remaining stroke error is 1ml! , 0.1 mm.

If detection is possible at 0.01 mm, it is also possible to detect errors in mold clamping force that are suppressed to 1.66%, 0.17%, and 0.017%, respectively.

However, in reality, it is sufficient to be able to detect a difference in remaining stroke of about 1 mm.

In the case of a machine with a mold clamping force of 1650 tons, in order to know whether the mold clamping force is within the tolerance of 5 mm, as mentioned above, check whether the remaining stroke of the piston rod 8 is within the tolerance of 3.3 mm. For example, if the mold clamping force is 800
In order to know whether the tie bar 19 is within the tolerance of 5 ton for a machine with 1650 ton of mold clamping force,
Since this is different from the case of ton, it is necessary to detect whether the remaining stroke of the piston rod 8 is within a tolerance of 2 mm.

In this way, the allowable error of the remaining stroke of the piston rod 8 varies depending on the size of the machine, which has a different mold clamping force, so the distance between the two limit switches A and H, etc. should be determined according to the allowable mold clamping force. The mold contact detection device 11 differs depending not only on the range but also on the size of the machine6.Although the mold contact detection device 11 is illustrated as a pressure switch in the above embodiment, it is not limited to this, and for example, as shown in FIG. Detection may be performed using a limit switch indicated by the reference numeral 13 or other devices.

By the way, when limit switches A and B of the remaining stroke detection device 10 are both OFF, the mold clamping force is insufficient, and when both are ON, the mold clamping force is too large.

Therefore, it is only necessary to issue a warning by displaying the respective information, or to stop the operation of the mold clamping cylinder and make adjustments.

As is clear from the above description, according to the present invention, it is detected whether the piston rod of the mold clamping cylinder has a predetermined remaining stroke when the movable mold contacts the fixed mold during the mold clamping operation. Piston rod remaining stroke detection device,
The mold contact detection device is installed at a position where it can be activated by the movement of the detection rod attached to the piston rod of the mold clamping cylinder, and detects when the movable mold contacts the fixed mold. It is possible to accurately detect whether the mold clamping force is normal, and excellent effects such as a simple structure and low cost can be obtained.

Further, in the present invention, it is possible to detect whether a regular mold clamping force is obtained when the movable mold contacts the fixed mold during a mold clamping operation.

In other words, it is possible to detect whether a normal mold clamping force is obtained before mold clamping is completely completed and no force is applied to the mold, tie bars, etc. yet.

Therefore, it is possible to quickly know whether the mold clamping force is too much or too little.

In particular, if the actual mold clamping force is larger than the desired mold clamping force and the machine is loaded, it may cause stress to various parts of the machine, shorten the life of the machine, and, in some cases, cause damage to the tie bars, platen, etc. This can be prevented by making it possible to immediately stop the mold clamping operation when excessive mold clamping force is detected.

And, when the machine is operated continuously, the temperature of the mold rises too much, causing expansion heat distortion and causing the machine to overload. You can do it like this.

Of course, if the mold clamping force is too high or insufficient, you can avoid clamping until the end and open the mold immediately.
It reduces wasteful movements, prevents energy loss, and reduces the time it takes to adjust the mold clamping force by stopping it early.

In addition, since it is possible to know whether the remaining stroke of the piston rod is normal when the mold is in contact, it is possible to know if there is any debris or foreign matter between the dividing surfaces of the mold. , is safe.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a longitudinal section, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 shows the remaining stroke of the piston rod, mold clamping force, and tie bar. It is a diagram showing the relationship between elongation of 1... Fixed platen, 2... Fixed mold, Total... Movable platen, 4... Movable mold, 5... Trouble mechanism,
7... Mold clamping cylinder, 8... Piston rod, 9...
...Detection rod, 10...Remaining stroke detection device, 1
1... Mold contact detection device, 12... Control circuit, 14
... Link housing, 17 ... Machine base, 18
... Bracket, 19... Tie bar.

Claims (1)

[Claims] 1. A piston rod remaining stroke detection device that detects whether the piston rod of the mold clamping cylinder has a predetermined remaining stroke when the movable mold contacts the fixed mold during mold clamping operation is installed on the piston rod of the mold clamping cylinder. It consists of two position detectors, such as limit switches or pulse transmitters, which are arranged at a predetermined distance from each other and are actuated by the movement of a detection rod attached to the detection rod. The movement trajectory part of
A mold contact detection device is installed at a predetermined position on the fixed part that is integrated with the machine base, link housing, etc. of the trouble molding tightening device and detects when the movable mold comes into contact with the fixed mold. This trouble mold clamping device is equipped with a control circuit that outputs a signal indicating whether the mold clamping force is normal or excessive or insufficient when the mold comes into contact with the detection device and the piston rod remaining stroke detection device, and a mold clamping force normal or abnormal display device.