JPH05131257A - Device for detecting abnormality in die clamping - Google Patents

Abstract

PURPOSE:To carry out the detection of abnormality in die clamping with a high accuracy at all times regardless of a difference in the thickness of dies and the thermal expansion, etc., thereof. CONSTITUTION:Pressurized air is supplied form an air circuit 38 in the die clamping state in which die mating surface 24 and 26 come into tightly contact with each other and is ejected from the through-hole 30 of a nozzle member 32 toward the die matting surface 24 of the stationary die 16. Whether the air pressure in a piping 48 is made to exceed the preset pressure by the flowing resistance of the air or not in such a case is detested by a pressure switch 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping abnormality detecting device for detecting whether or not a pair of molding dies are in close contact with each other when clamped.

[0002]

2. Description of the Related Art A pair of molding dies, such as a mold casting machine, are relatively brought close to each other and clamped to form a product cavity, and the product cavity is filled with molten metal or the like for molding. In the molding apparatus, if there is a gap on the mating surface due to foreign matter or the like, there is a problem that burrs are generated in the product or the molding material leaks from the mating surface. Therefore, it has been proposed to detect the relative positions of the pair of molding dies at the time of mold clamping with a limit switch or the like to determine whether or not the mold is completely clamped.
The device described in JP-A-61-245953 is an example.

[0003]

By the way, since the above-mentioned molding die generally has a high temperature and a sensor such as a limit switch cannot be directly mounted, it is mounted on a die base or the like which holds the molding die. When using molding dies having different mold thicknesses, it is necessary to change the mounting position of the sensor each time, which is a troublesome work. Also, because the relative position of the die base, etc. during mold clamping changes due to the thermal expansion of the molding die, it is not always possible to obtain sufficient accuracy in detecting mold clamping abnormalities, and fine adjustment is performed to eliminate the effects of thermal expansion. It was necessary to carry out a complicated calculation process.

The present invention has been made in view of the above circumstances, and an object thereof is to always detect a mold clamping abnormality with high accuracy regardless of a difference in mold thickness of a molding die, thermal expansion, and the like. To do so.

[0005]

In order to achieve such an object, the gap between the mating surfaces of the pair of molding dies can be directly detected, and the present invention can be made relatively close to each other. A mold clamping abnormality detecting device for detecting whether or not a pair of molding dies that form a product cavity by being clamped are in close contact with each other when the mold is clamped,
(A) An air passage that is provided in one of the pair of molding dies and that opens toward the mating surface of the other molding die.
(B) an air circuit that is connected to the one molding die and communicates with the air passage, and causes air to flow through the air passage; and (c) is provided in the air circuit to control the flow rate or pressure of the circulating air. And an air sensor for detecting.

[0006]

That is, in the state where the pair of molding dies are clamped, the opening of the air passage provided in one of the molding dies is close to the mating surface of the other molding die or Although they are brought into close contact with each other, if pressure air is supplied to the air passage or air is sucked in from the air passage in that state, the flow rate and pressure of the air flowing through the air passage will change with the opening of the air passage and the mating surface. It changes depending on the size of the gap between the and. Therefore, by detecting the flow rate and the pressure of the circulating air at this time with the air sensor, it is possible to detect whether or not the mold matching surfaces of both molding dies are in close contact with each other.

As described above, since the mold clamping abnormality detecting device of the present invention is designed to directly detect the gap between the pair of molding dies, the mold clamping surface may be completely affected by the thermal expansion of the molding dies. Since it is possible to always detect mold clamping abnormalities with high accuracy, there is no need to perform fine adjustment or complicated arithmetic processing to eliminate the effect of thermal expansion, and the device can be configured easily and inexpensively. is there. Even when multiple types of molding dies with different mold thicknesses are exchanged and used, if an air passage is provided in advance in one of the pair of molding dies, the mold clamping error can be solved simply by reconnecting the air circuit. It can be detected, and there is no need to perform troublesome adjustment work or the like depending on the mold thickness. In addition, since the molding die, which has a high temperature, is provided with an air passage with no moving parts, and the air sensor for detecting mold clamping abnormality is arranged away from the molding die, malfunction of the sensor due to heat can be avoided. The mold clamping abnormality can be detected with high reliability.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a fixed die base 12 and a movable die base 14 of a die casting apparatus 10 are fixedly mounted with a fixed molding die 16 and a movable molding die 18 facing each other. Molding surfaces 20 and 22 are formed on the fixed molding die 16 and the movable molding die 18, respectively,
The movable die base 14 is driven downward by a ram (not shown), and the mold matching surfaces 24 and 26 of both molding dies 16 and 18 are brought into close contact with each other as shown in the figure, so that the molding surfaces 20 and 22 cause a predetermined product cavity. 28 is formed. Then, in this state, the molten metal is poured into the product cavity 28, so that the product cavity 28
A product with the same shape as is cast.

A nozzle member 32 having a through hole 30 formed in its axial center is screwed and embedded in the die-matching surface 26 of the movable molding die 18. The through hole 30 is formed in the movable molding die 18. It communicates with a communication hole 34 provided from the side surface. The lower opening of the through hole 30, that is, the nozzle member 32
The lower end surface of the is aligned with or slightly recessed from the mating surface 26 so as not to obstruct the close contact between the mating surfaces 24 and 26 during mold clamping. On the other hand, in the mold matching surface 24 of the fixed molding die 16, the air escape groove 36 is formed from the side edge so as to reach the portion facing the opening of the through hole 30.
Is provided. The through hole 30 and the communication hole 34
Corresponds to the air passage provided in one of the molding dies, and the movable molding die 18 corresponds to one of the molding dies in the present embodiment.

The movable molding die 18 also has a communication hole 3
An air circuit 38 for supplying pressurized air of a predetermined constant pressure to 4 is connected. Air circuit 38
Is a switching valve 42 that cuts off the flow of the pressure air supplied from the pressure air supply source 40, a pressure reducing valve 44 that reduces the pressure of the pressure air to a constant pressure, and a pressure valve that reduces the pressure air to the constant pressure. A flow rate adjusting valve 46 for adjusting the flow rate to a constant amount is provided, and the pressure air whose constant pressure and the constant flow rate are adjusted is supplied to the communication hole 34 via the pipe 48. A connecting tool (not shown) is attached to the tip of the pipe 48 to connect the communication hole 34.
It is adapted to be detachably coupled to a coupling port provided at the opening of the.

The pressure air supplied from the air circuit 38 to the communication hole 34 is ejected from the through hole 30 of the nozzle member 32 toward the mating surface 24 of the fixed molding die 16 and passes through the air escape groove 36. However, the flow resistance of the air changes depending on the size of the gap between the opening of the through hole 30 and the bottom surface of the air escape groove 36, and the air pressure in the pipe 48 changes as the flow resistance changes. Change. That is, when the mating surfaces 24 and 26 of the two molding dies 16 and 18 are brought into close contact with each other and the gap between the opening of the through hole 30 and the bottom surface of the air escape groove 36 is small, the air flow resistance is reduced. Although it is large and the air pressure in the pipe 48 is high, a gap is created between the mold matching surfaces 24 and 26 due to foreign matter being caught, and the gap between the opening of the through hole 30 and the bottom surface of the air escape groove 36 becomes large. ,
The flow resistance of the air is reduced and the air pressure in the pipe 48 is reduced.

A pressure switch 50 is connected to the pipe 48 as a pressure sensor, and when the air pressure in the pipe 48 exceeds a predetermined set pressure, a pressure signal S is sent to the control panel 52.
It outputs A. The set pressure of the pressure switch 50 is set to a value slightly lower than the air pressure in the pipe 48 when the mating surfaces 24 and 26 of both molding dies 16 and 18 are completely brought into close contact with each other. 24, 26
When the molding dies 16 and 18 are clamped so that they come into close contact with each other, the pressure signal SA is output, but when there is a gap between the mating surfaces 24 and 26 due to foreign matter being caught or the like. Does not output the pressure signal SA.

The control board 52 controls the operation of the die casting machine 10 in accordance with a predetermined sequence, and the switching valve in a state where the movable die base 14 is lowered and both the molding dies 16 and 18 are clamped. 42 and open the communication hole 34
Supply pressurized air to. Then, when the pressure signal SA is supplied from the pressure switch 50 within a predetermined constant time, the molten metal is subsequently poured into the product cavity 28 for casting, but the pressure switch 50 causes the pressure to rise. If the signal SA is not supplied, the casting is stopped and the indicator 5
An error display showing the mold clamping error is displayed in 4. As a result, when a gap is created between the mating surfaces 24, 26 due to foreign matter being caught, the casting is continued as it is, burrs are produced in the cast product, and molten metal leaks from the gap. The problem is avoided.

Here, in this embodiment, a pair of molding dies 1 is used.
Since the gaps between the mating surfaces 24 and 26 of the molds 6 and 18 are directly detected, the mold clamping abnormality can always be detected with high accuracy without being affected by the thermal expansion of the molding dies 16 and 18. In addition, there is no need to perform fine adjustment or complicated arithmetic processing in order to eliminate the influence of the thermal expansion, and the device is simple and inexpensive. Even when a plurality of types of molding dies having different mold thicknesses are exchanged and used, the nozzle member 32 and the communication hole 3 are provided in each molding die.
4. By providing the air escape groove 36 in advance, the mold clamping abnormality can be detected only by reconnecting the pipe 48 of the air circuit 38, and it is not necessary to perform troublesome adjustment work or the like depending on the mold thickness. However, when the individual difference of the nozzle member 32 of each molding die and the processing tolerance of the air escape groove 36 are relatively large, it is desirable to adjust the set pressure of the pressure switch 50 every time the mold is replaced. Further, only the air escape groove 36, the communication hole 34, and the nozzle member 30 are provided in the molding dies 16 and 18 which become high temperature, and the pressure switch 50 for detecting the mold clamping abnormality is separated from the molding dies 16 and 18. Since the switch is provided, malfunction of the switch due to heat can be avoided, and mold clamping abnormality can be detected with high reliability.

Since a certain amount of air flows out from the air escape groove 36 even in the normal state, when the air pressure in the pipe 48 becomes abnormally high, the through hole 30 of the nozzle member 32 is formed.
It can be considered that the mold clamping error is detected, and by using a two-position setting type sensor or the like to determine whether the air pressure is within a predetermined range, it is possible to further improve the detection accuracy of the mold clamping abnormality.

In the above example, the case where the nozzle member 32, the communication hole 34, and the air escape groove 36 are provided at one location of the molding dies 16 and 18 has been described.
The nozzle member 32, the communication hole 34, and the air escape groove 36 are provided at a plurality of positions of 18, and the air circuit 38 is connected to each of them, and the mold clamping abnormality occurs depending on whether or not the pressure signal SA is output from all the pressure switches 50. Can be detected with higher accuracy.

Further, the nozzle member 3 is attached to the molding dies 16 and 18.
When it is difficult to directly install the blocks 2, as shown in FIG. 2, the blocks 60 and 62 are integrally formed in the vicinity of the mold matching surfaces 24 and 26 of the molding dies 16 and 18, as shown in FIG. Is fixed to the blocks 60 and 62, and the air escape groove 36
Alternatively, the nozzle member 32 may be provided. In carrying out the present invention, the blocks 60 and 62 can be regarded as constituting a part of the molding dies 16 and 18, respectively.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, although the nozzle member 32 is provided in the movable molding die 18 in the above embodiment, the nozzle member 32 is provided.
It is also possible to dispose on the fixed molding die 16. The movable molding die 18 is provided without separately providing the nozzle member 32.
It is also possible to directly form the air passage in the above.

Further, in the above-mentioned embodiment, the fixed mold 16 is provided with the air escape groove 36. However, even if the air escape groove 36 is not provided, the effect of the present invention can be sufficiently obtained.
It is also possible to provide the air escape groove 36 in the movable molding die 18 in which the nozzle member 32 is arranged.

Although the pressure switch 50 is used as the air sensor in the above embodiment, it is also possible to measure the air flow rate with an air flow meter or the like to detect the size of the gap.

Further, in the above embodiment, the pressure air is supplied to the communication hole 34, but the air may be sucked by a vacuum pump or the like.

Although not specifically exemplified, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a mold clamping abnormality detection device that is an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the main parts of another embodiment of the present invention.

[Explanation of symbols]

 16: Fixed molding die 18: Movable molding die 28: Product cavity 30: Through hole 34: Communication hole 38: Air circuit 50: Pressure switch (air sensor) 60, 62: Block (molding die)

Claims (1)

[Claims] 1. A mold clamping abnormality detecting device for detecting whether or not a pair of molding dies that form a product cavity by being relatively close to each other to form a product cavity are in close contact with each other during the mold clamping. And an air passage that is provided in one of the pair of molding dies and opens facing the mating surface of the other molding die, and is connected to the one molding die to communicate with the air passage. An apparatus for detecting mold clamping abnormality, comprising: an air circuit for circulating air through the air passage; and an air sensor provided in the air circuit for detecting the flow rate or pressure of the circulating air.