JPH054988Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a mold protection device for a mold clamping device.

[Prior Art] In the mold clamping device of a molding machine such as a transfer molding machine or an injection molding machine, there are cases where the molded product does not completely fall from the mold and is left behind in the mold, or the insert material etc. If the mold is clamped when the mold is out of its proper position, the mold surface will be damaged. In order to prevent this, various mold protection devices are attached to mold clamping devices and put into practical use.

As a conventional mold protection device,
As described in Publication No. 27429, the mold mounting plate for mounting a fixed mold is movable with a small stroke relative to the tie bar, and the direction of the mold mounting plate for mounting a movable mold is adjusted by a spring. If there is a foreign object between the molds, a force is applied to the fixed mold through the foreign object before the movable mold reaches the specified position, causing the spring to be compressed. As described in Japanese Utility Model Publication No. 45-27098, the tie bar is equipped with a strain gauge to detect the slight clamping force generated between the movable mold and the fixed mold. , as described in Japanese Patent Application Laid-Open No. 49-99157, the moving speed of a mold mounting plate for mounting a movable mold is detected, and the frequency corresponding to the detected moving speed is below a predetermined frequency. There is a known device that stops the mold closing operation when the temperature reaches that point.

[Problems to be solved by the invention] However, with these conventional mold protection devices, when the thickness of the foreign object sandwiched between the molds is thin,
The disadvantage is that the trapped foreign object cannot be detected.

[Means for Solving the Problems] The mold protection device of the mold clamping device according to the present invention includes a first mold mounting plate for mounting a movable mold and a second mold mounting plate for mounting a fixed mold. a mold mounting plate, and the movable mold and the fixed mold are clamped by moving the first mold mounting plate along the tie bar with respect to the second mold mounting plate. In the mold clamping device, a sensor (or cam rod) is attached to the fixed side of the tie bar fixing plate or the fixed mold, and the sensor is attached to the movable side of the first mold mounting plate or the movable mold. and a cam rod (or sensor) mounted at a position facing the cam rod, and the sensor has a movable member that protrudes toward the cam rod, and the amount of movement of the movable member when the movable member of the sensor hits the cam rod. when a predetermined period of time has elapsed after starting the mold closing operation, when the amount of movement detected by the detection means does not reach a predetermined movement range, or when the amount of movement detected by the detection means does not reach a predetermined movement range, When the movement range is exceeded,
The feature is that the mold closing operation is stopped.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

Referring to FIG. 1, mold clamping device 1 according to the present invention
0 has a first mold mounting plate 12 for mounting a movable mold 11 and a second mold mounting plate 14 for mounting a fixed mold 13. The mold clamping device 10 clamps the movable mold 11 and the fixed mold 13 by moving the first mold mounting plate 12 with respect to the second mold mounting plate 14 along the tie bars 15. .

The mold protection device 20 attached to the mold clamping device 10 of this embodiment is attached to the tie bar 15 via a sensor attachment 22 by a mold protection device attachment 21 as shown in FIG. sensor 23
and a cam rod 24 attached to the first mold mounting plate 12 at a position facing the sensor 23. The sensor 23 is a movable member 23 that protrudes toward the cam rod 24 in parallel with the longitudinal direction of the tie bar 15.
a, and a detection mechanism (not shown) that detects the amount of movement of the movable member 23a caused by the movable member 23a hitting the cam rod 24.

As this sensor 23, a differential transformer or a potentiometer is used.

The mounting position of the sensor 23 is determined by vertically adjusting the sensor mounting tool 22 using a sensor position adjuster 25 using a screw mechanism. Here, the position of the sensor 23 is determined between the movable mold 11 and the fixed mold 13.
When the movable member 23a is pushed in by the cam rod 24, the movable member 23a is fixed at a position within the operating stroke of the sensor 23. Note that 26 is a cover that covers the sensor 23.

Referring to FIG. 3, the movable member 2 of the sensor 23
The pushing stroke x of 3a is supplied to the control device 32 via the signal converter 31, and
Based on this pushing stroke x, as will be described later, the mold clamping drive device 33 that drives the first mold mounting plate 12 is controlled.

Referring to FIG. 4, the sensor 23 has a mold clamping position detection range A and a mechanical stroke limit B.
That is, when the pushing stroke x of the movable member 23a of the sensor 23 exceeds the mechanical stroke limit B,
The sensor 23 will be damaged. Therefore, it is necessary to use the sensor 23 within a range where the pushing stroke x falls within the mold clamping position detection range A of the sensor 23.

Next, the operation of this embodiment will be explained.

First, the control device 32 starts a mold closing operation by generating a drive signal to the mold clamping drive device 33 of the mold clamping device 10. At the same time, the control device 32
Activate an internal timer (not shown). A predetermined period of time after starting the mold closing operation (activating the timer) (from the time required from when the first mold mounting plate 12 starts the mold closing operation from the lowest position until the mold is successfully closed) When the amount of movement (pushing stroke x) detected by the detection mechanism of the sensor 23 does not reach the predetermined amount of movement (but within the mold clamping position detection range A), the control device 32 determines that a foreign object is caught between the movable mold 11 and the fixed mold 13, and the mold clamping drive device 33
The mold closing operation is stopped by generating a stop signal to.

Also, the pushing stroke x is within the mold clamping position detection range A.
Even when the value exceeds the limit, the control device 32 stops the mold closing operation by generating a stop signal to the mold clamping drive device 33. Therefore, damage to the sensor 23 due to the pushing stroke x of the sensor 23 exceeding the mechanical stroke limit B can be prevented.
The mold clamping position detection range A is determined so that the length (B-A) is sufficiently longer than the overrun amount due to the delay in the stop operation of the mold clamping drive device 33 with respect to the mechanical stroke limit B. Ru.

In this way, in the mold protection device of this embodiment, since the movement amount of the movable mold 11 is detected by the sensor 23, even if the thickness of the foreign object sandwiched between the molds is thin, the It is possible to detect foreign objects.

[Effects of the invention] As explained above, according to the invention, 1. Since the amount of movement of the movable mold is detected by the sensor, even if the thickness of the foreign object sandwiched between the molds is thin, it can be detected. It is possible to detect trapped foreign objects.

2. As a calculation processing method within the control device, the amount of movement of the movable mold during normal mold clamping without foreign objects (or the repeated average value of several times) and the amount of movement of the movable mold at the time of detection are calculated. It is possible to obtain an accurate difference, it is possible to reliably detect a foreign object, and there is no need to directly make delicate adjustments to the sensor as in the past, so settings can be made remotely.

3. By providing a width to the mold clamping position detection range, the mold clamping drive device can be stopped in response to a mold clamping operation that deviates from the detection range, and damage to the sensor can be prevented even in the event of a sensor position adjustment error.

It has the following effects.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the configuration of an embodiment of the present invention, Fig. 2 is a front view seen from - in Fig. 1, and Fig. 3 is a control using the mold protection device shown in Fig. 1. FIG. 4 is a block diagram showing the configuration of the system, and is a diagram for explaining how to use the sensor shown in FIG. 1. 10... Mold clamping device, 11... Movable mold, 12...
...First mold mounting plate, 12, 13... Fixed mold,
14...Second mold mounting plate, 15...Tie bar,
20...Mold protection device, 21...Mold protection device mounting fixture, 22...Sensor mounting fixture, 23...Sensor,
23a...Movable member, 24...Cam rod, 25
...Sensor position adjuster, 26...Cover, 31...
...Signal converter, 32...Control device, 33...Mold clamping drive device.

Claims (1)

[Claims for Utility Model Registration] 1) A mold mounting plate having a first mold mounting plate for mounting a movable mold and a second mold mounting plate for mounting a fixed mold; In a mold clamping device that clamps the movable mold and the fixed mold by moving the mold mounting plate with respect to the second mold mounting plate along the tie bar, the tie bar fixing plate or A sensor (or cam rod) attached to the fixed side of a fixed mold, etc., and a cam rod (or sensor) attached to the first mold mounting plate or the movable side of the movable mold at a position facing the sensor. The sensor has a movable member protruding toward the cam rod, and a detection means for detecting the amount of movement of the movable member when the movable member of the sensor hits the cam rod, When a predetermined period of time has elapsed since the start of the movement, when the amount of movement detected by the detection means does not reach a predetermined movement range, or when the movement amount exceeds the predetermined movement range,
A mold protection device characterized by stopping the mold closing operation. 2) A mold protection device for a mold clamping device according to claim 1, wherein the sensor is a differential transformer. 3) A mold protection device for a mold clamping device according to claim 1, wherein the sensor is a potentiometer.