JPH0614927Y2 - Degassing state detector for die casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a device for detecting a degassing state in a die which is an index of a casting state in a die casting machine.

[Conventional technology]

In the die casting machine, when the molten metal is injected into the die, a means for releasing the gas in the die is taken.
This is because the pressure of the molten metal becomes insufficient due to the gas existing in the mold, resulting in many defective products.

Under such a technical background, Japanese Patent Application Laid-Open No. 61-20976.
Japanese Patent Laid-Open No. 1-2004 proposes a method of detecting a gas ejection state from a mold by using a gas venting sensor and performing casting control of a die casting machine based on the detected gas ejection state.

In this structure, a gas vent sensor is provided at an outlet of a gas vent passage communicating with the inside of a mold, and a diaphragm inside the sensor is displaced when gas is released from the outlet. It is intended to detect the degassing state from the displacement amount of.

[Problems to be solved by the device]

However, the one described in the above-mentioned Japanese Patent Laid-Open No. 61-209761 has a problem that the manufacturing cost becomes high because a sensor corresponding to a minute pressure change is used.

Moreover, since the sensor is exposed to the outside of the mold, the function of the sensor is impaired by dust and the like contained in the atmosphere around the sensor, which in turn causes a decrease in measurement accuracy and is reliable enough to withstand long-term use. There was also the problem of poor sex.

The present invention was made by focusing on such problems,
The purpose is to reduce the manufacturing cost,
Another object of the present invention is to provide a degassing state detection device for die casting that can withstand long-term use while avoiding the cause of deterioration in the measurement accuracy of the sensor.

[Means for Solving the Problems]

The degassing state detection device for a die casting according to the present invention discharges the gas in the die from the degassing vent and the gas outlet communicating with the die when the molten metal is injected into the die of the die casting machine for casting. And forming a diffuser part on the extension of the gas discharge port, which serves as a flow path for passing the jet of discharged gas, and forming a secondary flow path communicating with the diffuser part, and A wind speed sensor is provided in the flow passage.

[Action]

According to the above configuration of the present invention, when the molten metal is injected into the mold, the gas in the mold is discharged to the outside from the gas discharge port and the diffuser portion. At this time, in the secondary flow passage communicating with the diffuser portion, a secondary flow is generated due to the ejector action accompanying the gas release. This secondary flow is detected by a wind speed sensor arranged in the secondary flow passage, and by this, it is possible to accurately grasp the degassing state in the die which is an index of the casting state in the die casting machine. Becomes

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 showing the overall configuration, a gas vent vent 3 communicating with a mold cavity (not shown) is provided between the movable mold 1 and the fixed mold 2. The degassing vent 3 is formed so as to have a zigzag part, and a gap G and a width W are provided between the gas vent 4 and the gas discharge port 4.
It is formed in a slit shape (see FIG. 2).

A diffuser block 5 is arranged on the fixed mold 2. This diffuser block 5 is a fixed mold 2
A first block 5A fixed to the first block 5A and a second block 5B provided on the left side of the first block 5A in FIG.
The second block 5B is fixed to the first block 5A via bolts 9 in a state in which the respective joint end surfaces 8 of the blocks 5A and 5B are in contact with each other. Also, the first and second blocks 5A and 5B
A diffuser portion 10 is formed so as to communicate with the discharge port 4 in a state where they are joined together. This diffuser unit 10
The joint end faces 8 formed on the first and second blocks 5A and 5B are joined together, that is, a part is narrowed down in the illustrated state.
And the angle θ ₁ that gradually expands toward the outlet 4.
And a second diffuser portion 10B provided on the opposite side of the first diffuser portion 10A and having an angle θ ₂ that gradually expands outward. ing. Therefore, the gas in the mold is discharged into the atmosphere through the gas vent 3, the discharge port 4, and the diffuser portion 10.

The first and second secondary flow passages 11, 1 communicating with the first diffuser portion 10A are provided on both left and right sides of the first diffuser portion 10A in the figure in the diffuser portion 10.
2 are arranged opposite to each other, and a wind speed sensor 13 is arranged in the first secondary flow passage 11. The wind velocity sensor 13 measures the wind velocity of the secondary flow generated in the secondary flow passage 11 due to the ejector action generated when the gas in the mold is released to the atmosphere. The degassing state is detected and used as an index of the casting state. As this wind speed sensor 13, a known hot-wire wind speed sensor is used, and its configuration is shown in FIG.

In FIG. 3, Rw is a platinum heat wire, Rc is a temperature compensation wire, and constitutes a bridge circuit together with the resistors R _{1 to} R ₃ . Also,
I is a current flowing through the platinum hot wire Rw, V is a voltage across the platinum hot wire Rw, 28 to 30 are amplifiers, Tr is a transistor,
31 is the secondary flow velocity, so that the omission can be obtained.

Next, the operation of this embodiment will be described.

First, as shown in FIG. 1, the movable mold 1 and the fixed mold 2 are clamped. In this state, the diffuser portion 10 is located on the extension line of the gas discharge port 4.

Now, when the molten metal is injected into the cavity of a mold (not shown), the gas in the cavity is ejected into the atmosphere through the gas vent vent 3, the discharge port 4 and the diffuser portion 10 by the injection pressure of the material. At the same time, the secondary flow passages 11 and 12 try to inject air from the secondary flow passages 11 and 12 toward the diffuser portion 10 due to the ejecting action accompanying the ejection of the gas, and the wind velocity at this time is the wind velocity sensor 1
3 is detected.

Therefore, according to such an embodiment, the first and second secondary flow channels 11 and 12 are formed in the diffuser block 5, and the wind speed sensor 13 is arranged in the first secondary flow channel 11. Since it is not exposed to the outside, the adverse effect on the wind speed sensor 13 can be reduced, the cause of the deterioration of the measurement accuracy can be eliminated as much as possible, and the measurement result as an index of the casting state can be reliable. There is.
In addition, since the wind speed sensor 13 is not exposed to the outside, damage due to contact with related devices can be prevented.

Furthermore, since the wind speed sensor 13 is configured by using a known sensor and does not use the diaphragm or the like exemplified as the prior art, the manufacturing cost can be reduced.

In the description of the above-mentioned embodiment, the first and second flow paths 11 and 12 are formed as the flow paths for generating the secondary flow, but it is sufficient that at least one secondary flow path is formed. The communication position between the secondary flow passages 11 and 12 and the diffuser portion 10 is not limited to the illustrated configuration example. For example, the opening of the secondary flow passage faces the narrowed portion of the diffuser portion 10. You can also However, the configuration of the above-described embodiment has an advantage that the secondary flow passage in the diffuser block 5 can be easily formed.

Further, the opening angles θ ₁ and θ ₂ of the diffuser portion 10 can be arbitrarily changed in design.

[Effect of device]

As described above, according to the present invention, it is possible to provide a degassing state detection device for die casting, which can reduce the manufacturing cost, avoid the cause of the deterioration of the measurement accuracy of the sensor, and can withstand long-term use. The effect is that you can do it.

[Brief description of drawings]

1 is a sectional view of a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a block diagram of a wind speed sensor. 1 ... moving mold, 2 ... fixed mold, 3 ... gas vent, 4 ... gas outlet, 5 ... diffuser block,
10 ... Diffuser section, 11 ... First secondary flow passage,
12 ... second secondary flow passage, 13 ... wind speed sensor.

Claims (1)

[Scope of utility model registration request] 1. When a molten metal is injected into a die of a die casting machine for casting, the gas in the die is discharged from a gas vent and a gas outlet communicating with the vent, and the gas is discharged. On the extension line of the outlet, a diffuser part that serves as a flow path for passing the discharged gas jet is formed, and a secondary flow path communicating with this diffuser part is formed, and a wind speed sensor is provided in this secondary flow path. An apparatus for detecting a degassing state for die casting, characterized by being provided.