JP2000024765A - Method for coating releasing agent for casting die casting product and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the casting quality by providing a flow metal and a solenoid valve in series in a releasing agent supplying route arranged so as to approach a nozzle in an air blow route to restrain uneven dispersion of the coating quantity of the releasing agent on the cavity in a die. SOLUTION: The flow meter 1 and the solenoid valve 3 for releasing agent are disposed on the way of the releasing agent route 5, and at the time of opening the movable die in a casting machine, lowering a spray unit, opening a solenoid valve 3 for air and starting the air blow, and simultaneously, opening the solenoid valve 2 for releasing agent, the releasing mist mixing air 7 obtd. from an air-releasing agent mixing machine 4 is blown. The coating quantity of the releasing agent is measured by the flow meter 1, and at the time of reaching the prescribed quantity, the solenoid valve for releasing agent is closed with an electric signal to stop coating of the releasing agent. In this way, it comes to a state, where only the air blow is successively working. The air blow is stopped after a prescribed time passes from the start, but a timer is set for the time longer than the coating time of the releasing agent. In the case of occurrence of uneven dispersion of the spray time, the adverse effect to the casting cycle is not given, since the total time of the air blow is set with the timer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for die casting of aluminum alloy, zinc alloy and the like.

[0002]

2. Description of the Related Art Die casting is a technique widely used as a method of injecting a molten metal such as an aluminum alloy, a zinc alloy or a magnesium alloy into a mold at high pressure and high speed to obtain a product. At the time of this casting, a release agent is widely used in order to improve the mold release of the product and to prevent the occurrence of galling, distortion and the like. The release agent has oiliness and aqueousness, and is appropriately selected and used in consideration of the type of the casting alloy and the wettability to an appropriate mold temperature. Taking the case of an aluminum alloy as an example, it is general that the casting is continuously performed at a molten metal casting temperature of 610 to 750 ° C. and a mold temperature of 150 to 250 ° C. on the cavity surface. Therefore, in this case, the wetting temperature of water is 195 to
Since the temperature is 215 ° C., the water-soluble release agent is used after being appropriately diluted. The method of applying the mold release agent to the mold cavity surface, which has been widely used in the past, is based on the principle of spraying, and sprays pressurized air to release the mold release agent diluted with water for a certain period of time. It is a method of mixing and spraying. However, such a method of applying a release agent has a technical problem that the actual amount of the release agent largely fluctuates due to a change in air pressure or a change in the remaining amount of the release agent in the release agent tank. If the amount of the release agent applied is insufficient, the product tends to suffer from seizure failure and galling failure.If the amount of the release agent applied is too large, the mold temperature becomes too low due to heat of evaporation of moisture. Appearance defects such as hot water wrinkles, blisters, and cavities due to the release agent are likely to occur. In order to prevent such a variation in the amount of the release agent applied, an airless type high-pressure spraying device has also been developed. However, it is generally very expensive or the pressure is too high, which increases the danger in operation. Often.

[0003]

In principle, it is possible to drastically reduce the variation in the amount of the release agent applied while adopting the method of applying and spraying the release agent by air pressure which has been widely practiced in the past. An object of the present invention is to provide a method for applying a release agent and an apparatus for applying the same.

[0004]

It has been experimentally found that in die casting, controlling the applied amount of the release agent to a predetermined fixed amount directly contributes to maintaining the quality of the cast product. As a result, the inventors of the present application have intensively studied and as a result, have come to the invention of the following problem solving means.

[0005] A flow meter and an electromagnetic valve are provided in the middle of the supply pipe of the release agent, the movable mold of the casting machine is opened, the spray unit is lowered to start air blowing, and at the same time the electromagnetic valve is opened to release the release agent. Apply. On the other hand, the application amount of the release agent is measured by a flow meter, and when the amount reaches a predetermined amount, the electromagnetic valve is closed by an electric signal to stop the application of the release agent. As a result, only the air blow is continuously operated. A timer is operated at the same time as the start of the air blow, and the air blow is stopped after a predetermined time has elapsed. However, the timer is set so that the air blow is longer than the release agent application time.

[0006] The release agent application time is also measured, and an electric circuit is set so that an abnormal signal is output when the release agent application time is longer than a predetermined time.

[0007]

EXAMPLE A die having a weight of 7200 g was attached to a die casting machine called 800 ton, and a pulse signal detection type / volume type micro flow meter was provided in the release agent supply piping system as shown in FIG. 1 and the flow rate was set to 900 ml. 5 times the total air blow time
It was set to seconds and continuous casting was performed 120 times. As a result, the variation in the amount of the release agent applied was only 0.75 ml in the sample standard deviation, and the average application time at that time was 3.5 seconds. As a result, the time for only the air blow was 1.5 seconds. The cycle time was stable at 56.5 seconds to 57.2 seconds, and the appearance of each product was good. On the other hand, for comparison, when the mold was set to apply the release agent for 3 seconds in a conventional pipe and continuous casting was performed 120 times, the average application amount was about 1000 ml, the variation was 73 ml in sample standard deviation, and the appearance quality was unstable.

[0008]

According to the present invention, the variation in the amount of the release agent applied to the mold cavity surface can be kept very small as compared with the prior art, and the casting quality can be improved.
Further, even if the spray time varies somewhat due to the control of the amount of the release agent applied, the total air blow time is set by a timer, so that the casting cycle time is not affected at all. Further, since the release agent spray time is counted, if the time is longer than a predetermined time, there is an effect that facility abnormality such as nozzle clogging can be recognized in advance or early.

[Brief description of the drawings]

FIG. 1 is a schematic view of a supply path of a release agent.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flow meter 2 ... Solenoid valve for mold release agent 3 ... Solenoid valve for air 4 ... Mixer for air and mold release agent 5 ... ··· Release agent path 6 ···· Air path 7 ··· Release agent mist mixed air

Claims (3)

[Claims] An apparatus for applying a release agent to a mold cavity having a release agent supply path connected to a nozzle of an air blow path and having a flow meter and an electromagnetic valve serially connected to the release agent supply path. A release agent coating device, which is provided. 2. The route is automatically cut off when a predetermined time has elapsed after the start of air blowing.
An apparatus for applying the release agent according to the above. 3. A method for die-casting using the coating apparatus according to claim 1.