JPH06315755A - Method for confirming close contact of dies in die-clamp forming machine - Google Patents

Abstract

PURPOSE:To confirm close contact of dies in a good accuracy at the time of die-clamping in each forming cycle, in a die-clamp forming machine having die-clamping mechanism of a die casting machine, resin injection forming machine, etc. CONSTITUTION:The stroke end value SE of a slide 3 at the time of die-clamping in each forming cycle is detected with a stroker 6 and stored in an arithmetic storing part 8 in a control panel 7 and on the other hand, the stroke end value SE at the preceding time in each forming cycle continuously executed is made to be the stroke end reference value SS at the time of die-clamping in each forming cycle. Then this reference value SS and the stroke end value SE detected at the time of the die-claming, are compared and calculated with the arithmetic storing part 8 and the differential value between both is displayed on a displaying part 8a and the close contact of dies is confirmed by the information, in which the displayed value is the value within the preset permissible range. Therefore, without being affected by the environment around the die, the thermal expansion of the die is corrected and the close contact of the dies in each forming cycle continuously executed, can be confirmed in the good accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die-clamping molding in which a pair of dies are clamped by a die-clamping mechanism with a high force like a die-casting machine or a resin injection molding machine, and a molten metal is pushed into the cavity for molding. Regarding the machine, in detail, at the time of mold clamping in each molding cycle that is continuously performed, make sure that the kiss surfaces of the pair of molds are in close contact with each other and that no foreign matter such as burrs is caught,
The present invention relates to a mold contact confirmation method for a mold clamping molding machine, which prevents in advance accidents such as molten metal blowing during molding.

[0002]

2. Description of the Related Art In a die-clamping machine having a die-clamping mechanism such as a die-casting machine or a resin injection molding machine, a pair of dies are clamped with high force and then molten metal or resin is injected into the cavity. Casting or injection molding, but foreign matter such as burrs generated in the previous molding cycle may adhere to the mold, which may cause a state where the kiss faces of the pair of molds do not sufficiently adhere, If casting or injection molding is performed in this state, product defects may occur and there is a risk of accidents such as molten metal blowing.

As a method for confirming the close contact of the molds at the time of mold clamping of these mold clamping molding machines, a method of visually confirming by an operator has been conventionally used. Due to low productivity, methods such as confirmation with a TV camera and confirmation with an air gap sensor have been widely adopted in recent years.

In the confirmation method using a TV camera, as shown in the conceptual diagram [FIG. 4], the molds (41) and (42) before mold clamping are opened with the molds (41) and (42) open. 41), (4
The kiss surface side of 2) is photographed by the TV cameras (43) and (44), and the image processing detects the presence of burrs. Also,
In the confirmation method using the air gap sensor, as shown in the conceptual diagram (FIG. 5), the pair of molds (51), (52)
A plurality of small diameter holes (52a) are provided on the kiss surface of one of the molds (52), and pressure is applied to the small diameter holes (52a) from the back side with air to achieve a perfect close contact (state in Figure (a)). ) And burrs (B) adhere to each other, resulting in a gap between the die kiss surfaces (incomplete adhesion).
(b) state) and measure the pressure values in advance, and compare the pressure values with the pressure values at the time of mold clamping in each molding cycle to confirm mold contact or burr engagement. To do.

[0005]

However, in a mold-clamping molding machine such as a die-casting machine or a resin injection molding machine, continuous molding is performed, and mold lubrication is performed before mold clamping in each molding cycle. The environment around the mold deteriorates due to the smoke from the lubricant. Therefore, with the confirmation method using the television camera, it is difficult to maintain a good visual field of the camera, the accuracy of the obtained image is deteriorated, and it is difficult to detect a small burr. Further, if the image sensitivity is increased to detect small burrs, it becomes easy to mistakenly recognize stains and the like due to lubricant as burrs, and it takes a wasteful time to deal with the mistakenly recognized burrs, which reduces productivity. Derive. Furthermore, this system has a problem that the cost of the system is relatively high.

On the other hand, in the conventional confirmation method using the air gap sensor, it is necessary to provide a plurality of minute diameter holes for pressure detection in the mold, and to provide communication holes and piping for sending air to these minute diameter holes. The mold structure becomes complicated and the manufacturing cost is high. Also, the holes for pressure detection have a very small diameter (usually about 1 mm), and the environment around the mold surface where they are installed deteriorates. Easily causes clogging. Therefore, in order to prevent clogging and maintain confirmation accuracy and reproducibility, a relatively high frequency of inspection / maintenance is forced, and there is a problem that the maintenance and management burden increases and productivity decreases.

The method of the present invention has been made in order to solve the above-mentioned problems of the prior art. It is possible to accurately check the die contact during mold clamping, and the apparatus configuration therefor is relatively simple. In addition, the accuracy of the confirmation can be maintained with high reproducibility without being affected by the environment around the mold, and thus the operation of the applicable mold clamping molding machine can be stabilized and its productivity can be further improved. It is an object of the present invention to provide a method for confirming mold contact with a molding machine.

[0008]

According to the present invention, a pair of molds are clamped in a mold clamping molding machine in which a pair of molds are clamped with a high force by a pressing means and molten metal is pushed into the cavity for molding. In the mold contact confirmation method of the mold clamping and molding machine, which confirms that the kiss surfaces are closely contacted with each other and that no foreign matter such as burrs is caught, and prevents molten metal leaks or the like during subsequent molding, In order to achieve the purpose, it is characterized by taking the following technical means. That is, the method of confirming the mold contact of the mold clamping molding machine of the first invention detects and stores the stroke end value of the rolling-down means at the time of mold clamping in each molding cycle, while continuously performing each molding cycle. The stroke end value one time before is set as the stroke end reference value during mold clamping in each molding cycle, and the reference value is compared with the stroke end value detected during the same mold clamping, and the difference is preset It is characterized in that the die adhesion is confirmed by the value within the range.

According to the second aspect of the present invention, there is provided a die contact confirmation method for a die-clamping molding machine, which detects and stores the stroke end value of the rolling-down means and the die temperature at the time of die-clamping in each molding cycle, while storing each die-molding cycle. The mold temperature value at the time of each mold clamping is compared with the mold temperature value one time before, and the thermal expansion / contraction value of the mold is calculated from the temperature difference, and the calculated thermal expansion / contraction value is 1 In addition to the previous stroke end value, it becomes the stroke end reference value at the time of mold clamping in each molding cycle, and
It is characterized in that the reference value and the stroke end value detected during the same mold clamping are compared, and the die contact is confirmed when the difference between the two is within a preset allowable range.

[0010]

In a die-clamping machine such as a die-casting machine or a resin injection molding machine, a pressure detector and a stroke detector are usually provided in the die pressure reducing means, which allows the die pressing force and the die pressing force at the time of die clamping. The amount of movement is controlled. Here, as the stroke detector of the rolling-down means, for example, by using a high-precision stroke detector such as a magnetostrictive stroke detector, it is possible to detect the die movement amount in units of 0.01 mm. . On the other hand, since the minimum thickness of the burr that occurs during molding with these mold clamping machines is approximately 0.2 mm, the stroke amount of the rolling-down means during mold clamping is detected with high accuracy in 0.01 mm units, and the detected value By comparing the value measured in the fully contact state with the preset stroke end reference value, it is considered possible to determine the bite of the minute burr.

However, since the molds of the mold clamping and molding machines receive the heat of the molten metal injected at each molding, even if they are cooled by a blower, cooling water or the like, under continuous molding [Fig. ] The temperature rises as shown in the graph of
There is a temperature difference of about 150 ° C before the start of molding and during continuous molding. Also, due to thermal expansion due to temperature rise, for example, in the case of a mold with a thickness of about 800 mm, the thickness variation value is about 1
Since it reaches mm, the stroke end reference value that does not consider the expansion amount of the die due to continuous molding cannot determine the bite of a minute burr, that is, simply by increasing the stroke detection accuracy of the rolling means, It is not possible to achieve mold contact confirmation in actual operation.

On the other hand, when the amount of change in mold temperature due to continuous molding is examined in detail, the normal molding cycle time in these mold clamping machines is about 1 minute, and the mold temperature after each molding cycle is It was found that the amount of change from the mold temperature in the previous molding cycle was minute, so that the variation value of the mold thickness was much smaller than the minute burr thickness. From these examination results, the inventors of the present invention use the stroke end actual measurement value of the rolling-down means of the previous molding cycle as the stroke-end reference value of the rolling-down means in each molding cycle, thereby changing the temperature in each molding cycle. It has been found that the stroke end reference value of the rolling-down means in each molding cycle can be made to follow the variation value of the thickness of the die with a slight delay, and the minute burr bite can be discriminated.

The first aspect of the present invention is made based on the above knowledge, and the stroke end value before each continuous molding cycle is set as the stroke end reference value at the time of mold clamping in each molding cycle. At the same time, the reference value and the stroke end value detected during the same mold clamping are compared, and the die contact is confirmed if the difference is within the preset allowable range. The stroke end reference value of the rolling-down means is made to follow the variation in the thickness of the die due to, and the die adhesion at the time of die clamping in each molding cycle can be accurately confirmed. Also, the stroke end value of the rolling-down means can be detected by
Since it can be performed with a stroke detector etc. that can be placed at a position spaced from the periphery of the die kiss surface, its detection accuracy is not affected by the environment around the die, and its accuracy and reproducibility are improved. Can be kept high. Moreover, it is not necessary to add special processing to the mold for that purpose.

The amount of thermal expansion / contraction of the mold is determined by the coefficient of thermal expansion / contraction of the material of the mold and can be grasped in advance as a functional relationship with the temperature change. Therefore, it is possible to detect the mold temperature value during mold clamping for each molding cycle, calculate the thermal expansion / contraction value of the mold from the temperature value, and know the variation value for each molding cycle.

A second aspect of the present invention is made from the above point of view. The die temperature value at the time of die clamping in each molding cycle is compared with the die temperature value one time before, and the die temperature is determined from the temperature difference. Calculate the thermal expansion / contraction value of the mold, add the calculated thermal expansion / contraction value to the stroke end value one time before, and set it as the stroke end reference value at the time of mold clamping in each molding cycle. And the stroke end value detected during the same mold clamping, and the mold contact is confirmed if the difference between the two is within the preset allowable range. Thus, even when the die temperature changes abruptly, it is possible to accurately check the die close contact at the time of die clamping in each molding cycle by the stroke end reference value of the pressing means corresponding to the change of the die thickness value. Further, the stroke end value of the rolling-down means can be detected by a stroke detector or the like which can be arranged at a position spaced from the periphery of the die kiss surface, and the die temperature can also be detected by a contact temperature measuring method or the like. Since the detection accuracy is not affected by the environment around the mold, the accuracy and reproducibility can be maintained high.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the mold contact confirmation method of the present invention will be described below with reference to the drawings. [FIG. 1] is an explanatory view of a first embodiment of the present invention, in which (a) is a front view showing a schematic configuration of a die casting machine used, and (b) is a view showing a change in a die thickness value. 6 is a graph showing a relationship between a stroke end reference value and a stroke end value.

First, referring to FIG. 1 (a), the die casting machine used in this embodiment will be described. This die casting machine has a die clamping cylinder device (4) on its upper part.
In addition, it is a vertical type that is equipped with a molten metal injection device (not shown here) at the bottom, and the fixed mold (D1) is fixedly mounted on the bolster (2) on the bed (1). Attach the moving mold (D2) to the lower surface of the slide (3) that moves up and down by the operation of the main ram (4a) of the mold clamping cylinder device (4). This is a very general structure in which the moving die (D2) is fastened with high force, and molten metal is pressure-fed into the cavity from a molten metal injection device (not shown) provided below the cavity.

Reference numeral (6) is a locator, which extends from the base (6a) attached to the top platen (5) of the machine body and extends downward from the base (6a). Body of rod-shaped ferromagnetic metal
It is a magnetostrictive type having (6b) and a ring-shaped moving part (6c) which is externally attached to the main body part (6b) and is attached to the slide (3). Further, the moving part (6c) moved on the main body (6a) in a non-contact manner as the slide (3) moved up and down, and generated in the axial magnetic field of the built-in magnet and the main body (6a). From the propagation time of the wave generated by the magnetic field line distortion due to the interference with the circumferential magnetic field, the stroke amount of the slide (3) is 0.01 mm.
Detect in units. Further, this strator (6) is connected to a control panel (7) arranged outside the machine body, and transmits the stroke value detected during mold clamping in each molding cycle to the control panel (7) as an electric signal.

On the other hand, the control panel (7) is an arithmetic storage unit for storing the stroke end value of the slide (3) at the time of mold clamping of each molding cycle detected by the locator (6).
(8) is provided. The calculation storage unit (8) calculates the difference value (±) between the stroke end reference value set for each molding cycle and the stroke end value detected during mold clamping in each molding cycle. The display unit (8a) displays the difference value in units of 0.01 mm. Further, the stroke end reference value for each molding cycle is also set by the stroke end value of the slide (3) detected at the time of mold clamping in the molding cycle immediately before that.

In the die contact confirmation method of this embodiment using the die casting machine having the above-mentioned structure, the display unit of the arithmetic storage unit (8) is used.
Since the value displayed in (8a) is within the preset allowable range (± 0.1 mm in this example), the mold kissing surface clearance is maintained during mold clamping in each molding cycle that is continuously performed. Make sure that the mold is in close contact without any burrs or other bites.

This will be described in more detail. First, the first
Usually, a fixed mold (D1) is used when clamping the mold for the second molding.
Since the kiss surface of the moving mold (D2) is in a clean state, the mold contact is achieved when these are clamped at a predetermined pressure. Therefore, at the time of the first molding, the molding is started only by checking the mold clamping pressure, and the stroke end value S _E of the slide (3) at the time of mold clamping is detected to calculate the arithmetic storage unit of the control panel (7). Store in (8).

At the time of mold clamping in the subsequent second molding cycle, the stored first stroke end value S _E is set as the stroke end reference value S _S at the time of molding, and this reference value S _S The calculated value of the difference from the stroke end value S _E of the slide (3) is calculated by the calculation storage unit (8), and the difference value is displayed on the display unit (8a). Check that the mold adheres when the same mold is clamped.

Here, the mold at the time of mold clamping in the second molding cycle is heated by the heat of the molten metal received in the first molding cycle, and the temperature value is increased due to the thermal expansion. However, since the amount of temperature change during that time is minute, the thickness variation value is much smaller than the minute burr thickness, which has a minimum thickness of about 0.2 mm. Therefore, in the present embodiment in which the allowable range is ± 0.1 mm, the value displayed on the display section (8a) is also a value within the allowable range, and the bite of the minute burr is also caught. It is possible to make a distinction, and by doing so, it is possible to confirm the close contact of the mold when the mold is clamped.

Then, at the time of mold clamping in each molding cycle subsequent to the second and subsequent times, as shown in the graph of (b), the stroke end value S _E detected and stored in the molding cycle immediately before that is stored. The stroke end reference value S _S is set, and the difference value between the reference value and the stroke end value S _E detected during mold clamping in each molding cycle is calculated and stored in the storage unit (8).
Is calculated and displayed on the display (8a), and the difference is ± 0.1 mm.
By confirming that the value is within the allowable range (the range from the white circle to the solid line), it is possible to confirm the mold adhesion during mold clamping in each molding cycle that is continuously performed. The curve A shown by the chain line in the graph of (b) shows the change in the thickness value of the mold due to thermal expansion, and the black circles indicate the stroke end positions detected during mold clamping in each molding cycle. The mark indicates the set stroke reference position, and the solid line in the vertical direction from the white circle mark indicates the allowable range.

In this embodiment in which the die contact is confirmed in this manner, as shown in the graph of FIG. 2 (b), the stroke end of the slide for pressing down the die against the variation value of the die thickness due to thermal expansion. The reference value S _S is made to follow with a slight delay and is corrected, so that it is possible to accurately check the die contact during mold clamping in each molding cycle that is continuously performed.

Further, the stroke end value detected for the confirmation is detected by a locator arranged at a position separated from the periphery of the die kiss surface, so that the detection accuracy affects the environment around the die kiss surface. Without being
The accuracy and reproducibility can be maintained high. Further, unlike the above-mentioned conventional technique, it is not necessary to install a TV camera or the like or to add special processing to the mold, the device configuration for detection is simple, and the burden required for its maintenance management is significantly reduced. Can be lowered to

If the molding to be continuously performed is interrupted for some reason, and it is recognized that the temperature of the mold has dropped by a relatively large amount due to the interruption, the first cycle of the molding cycle at the restart is performed. Computation memory unit
It is sufficient to cancel the memory of (8) once and then follow the procedure from the first time onward.

FIG. 2 is an explanatory view of the second embodiment of the present invention, where (a) is a front view showing a schematic structure of the die casting machine used, and (b) is a thickness value of the mold. 3 is a graph showing the relationship between the change in the stroke, the set stroke reference value, and the actually measured stroke end value.

The die casting machine used in this embodiment is different from the die casting machine except that a die temperature detecting device and an arithmetic device for calculating the die expansion / contraction value from the detected temperature value are attached. The configuration is the same as that of the first embodiment shown in FIG. 1 (a), and only the differences will be described here in brief.

In FIG. 2 (a), (9) and (9 ') are temperature measurement couples, and these temperature measurement couples (9) and (9') are connected to each other at their measurement tips. Fixed mold (D1) and moving mold (D2)
While it is inserted into the temperature measuring holes (D1a), (D2a) provided on the side of the, it is connected to the arithmetic unit (10) attached to the control panel (7) and detects the fixed mold (D1) and movement. The calculation unit (10) attached to the control panel (7) using the temperature value of the mold (D2) as an electric signal.
Tell.

Further, the calculation unit (10) uses the temperature data from the temperature measurement couples (9) and (9 ') based on a previously input calculation program to fix and move the molds (D1) and (D2). ) Is calculated, and the calculated mold thermal expansion / contraction value is transmitted to the calculation storage unit (8). The arithmetic program to be input in advance to this arithmetic unit (10) is a fixed and movable die (D
It is set / changed by the coefficient of thermal expansion / contraction of the material of 1) and (D2).

On the other hand, the arithmetic storage unit (8) calculates the value (±) of the difference between the thermal expansion and contraction values of the mold at the time of mold clamping in each molding cycle and at the time of mold clamping just before that. Then, the difference value is added to the stroke end value detected during the previous molding cycle to set the stroke end reference value during mold clamping in each molding cycle, and the reference value and the stroke end reference value detected during the same mold clamping. The difference value is calculated by comparing with the stroke end value. Then, the calculated difference value between the two is displayed on the display unit (8a) in units of 0.01 mm.

In the die contact confirmation method of this embodiment using the die casting machine having the above structure, the display unit of the arithmetic storage unit (8) is used.
Since the value displayed in (8a) is within the preset allowable range (± 0.1 mm in this example), the mold kissing surface clearance is maintained during mold clamping in each molding cycle that is continuously performed. Make sure that the mold is in close contact without any burrs or other bites.

In this embodiment in which the die contact is confirmed in this manner, as shown in the graph of FIG. 6 (b), the stroke end of the slide for pressing down the die against the variation value of the die thickness due to thermal expansion. The reference value S _S is more accurately tracked and corrected by actually measuring the mold temperature, so that the mold adhesion at the time of mold clamping in each molding cycle that is continuously performed can be accurately confirmed. Further, the stroke end value S _E detected for the confirmation is detected by a locator arranged at a position spaced from the periphery of the die kiss surface, and the die temperature is also detected by a temperature measuring hole on the side surface of the die. Since it is performed by the temperature measuring couple inserted into the mold, the detection accuracy thereof is not affected by the environment around the die kiss surface, and the accuracy and reproducibility can be maintained high. Further, even if the molding that should be continuously performed is interrupted for some reason, and the temperature of the mold largely changes due to the interruption, the stroke end reference value S _S is corrected by the actually measured mold temperature. It is possible to confirm the mold contact with high accuracy and high reproducibility during mold clamping in each molding cycle.

[0035]

As described above, according to the mold contact confirmation method of the mold clamping molding machine according to the present invention, the mold contact at the time of mold clamping can be accurately confirmed, and the apparatus configuration therefor can be provided. Relatively simple, its confirmation accuracy is not affected by the environment around the mold, high reproducibility can be maintained, and the operation of the mold clamping and molding machine to be applied is stabilized, and its productivity is further improved. be able to.

[Brief description of drawings]

FIG. 1 is an explanatory view of a first embodiment of the present invention, in which (a) is a front view showing a schematic configuration of a die casting machine used,
FIG. 6B is a graph showing the relationship between the change in die thickness value and the set stroke reference value and the actually measured stroke end value.

FIG. 2 is an explanatory view of a second embodiment of the present invention, in which (a) is a front view showing a schematic configuration of the die casting machine used,
FIG. 5B is a graph showing the relationship between the change in die thickness value and the stroke end reference value and the stroke end value.

FIG. 3 is a graph showing a relationship between elapsed time and mold temperature under continuous molding according to the present invention.

FIG. 4 is a conceptual explanatory view of a mold contact confirmation method using a conventional TV camera.

FIG. 5 is a conceptual explanatory view of a conventional die contact confirmation method using an air gap sensor.

[Explanation of symbols]

(1) --Bed (2) --Bolster (3) --Slide (4) --Clamping cylinder unit (4a) --Main ram (5) --Top platen (6) --Strator (7) --Control panel (8) --Math memory (8a) --Display (D1) --Fixed mold (D2) --Movable mold A --Mold thickness value S _E --Stroke end value S _S --Stroke end reference value

Claims (2)

[Claims] 1. A mold is clamped by a pressing means with a high force and a molten metal is pushed into the cavity for molding, and when the mold is clamped, the kiss faces of the pair of molds come into close contact with each other. In the method for confirming the mold contact of the mold clamping molding machine, it is necessary to confirm that there is no foreign matter such as bite in and prevent leakage of molten metal during subsequent molding. While detecting and storing the stroke end value of, the stroke end value before each molding cycle that is continuously performed is set as the stroke end reference value at the time of mold clamping in each molding cycle, and the reference value Comparing the stroke end value detected during the same mold clamping, and confirming the mold contact if the difference is within the preset allowable range, the mold contact confirmation of the mold clamping molding machine is characterized. Recognition method. 2. A pair of molds are closely clamped at the time of mold clamping in a mold clamping molding machine in which a pair of molds is clamped with high force by a pressing means and molten metal is pushed into the cavity for molding. In the method for confirming the mold contact of the mold clamping molding machine, it is necessary to confirm that there is no foreign matter such as bite in and prevent leakage of molten metal during subsequent molding. While detecting and storing the stroke end value and the mold temperature of the mold, the mold temperature value at the time of mold clamping in each molding cycle is compared with the mold temperature value one time before, and the mold difference is used from the temperature difference. The thermal expansion / contraction value of is calculated, and the calculated thermal expansion / contraction value is added to the stroke end value one time before to make the stroke end reference value at the time of mold clamping in each molding cycle. Strobe detected when clamping the mold A method for confirming the mold contact of a mold clamping machine, which is characterized in that the mold contact is confirmed when the difference between the two is within a preset allowable range.