JP2002263795A - Method for spraying releasing agent for die-casting machine, and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for spraying releasing agent for a die-casting machine, and a device thereof capable of uniformly coating the releasing agent on a die, and preventing temperature drop of the die. SOLUTION: The releasing agent is atomized and sprayed and coated on the surface in the die with the discharge pressure of the releasing agent consisting of water-soluble inorganic salt, etc., discharged from releasing agent discharge ports of a plurality of spray nozzles fitted to face and back sides of a spray unit being 1/2 of the ejection pressure of the air ejected from atomized air ejection ports opened around the releasing agent discharge ports.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for spraying a release agent for a die casting machine for applying a release agent to an inner surface of a die of the die casting machine.

[0002]

2. Description of the Related Art Heretofore, when molding by die casting, it has been necessary to spray-coat a release agent on the inner surface of a mold in order to facilitate release of the molded product. Release agents used in die casting include water-soluble inorganic salts such as sodium carbonate and potassium chloride and ethers for suppressing the rebound of the water-soluble inorganic salts, improving the elongation, and improving the adhesion to the mold. A mixture of a surfactant and a surfactant such as an ester or the like has been used. As shown in FIG. 5, the spray nozzle 11 for spraying such a release agent has a diameter of about 1.3.
The release agent is discharged from the release agent discharge port 10 toward the mixing chamber 12 at a discharge pressure of MPa, and air is discharged from the atomizing air discharge port 13 toward the mixing chamber 12 at a discharge pressure of about 0.4 MPa. By spraying, the release agent is atomized and sprayed from the spray nozzle 11 to coat the release agent on the inner surface of the mold. However, since the discharge pressure of the release agent is about three times higher than the ejection pressure of air, the release agent is hard to be atomized and is sprayed with a large particle size. There is a problem that the release agent attached to the mold easily flows down. In addition, since the mold release agent cannot be applied densely to the inner surface of the mold due to the large particle size, it has been necessary to repeat spraying and perform recoating. For this reason, there has been a problem that the release agent more easily flows down. Therefore, in the spray nozzle 11, a spraying experiment was performed under the condition that the discharge pressure of the release agent was reduced and the ejection pressure of the air was increased so that the pressure ratio was about 1: 3. In particular, spraying was unstable during the process, and the release agent could not be uniformly applied to the surface of the mold. In addition, the particle size of the release agent was not reduced, and good coating results could not be obtained.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a method for spraying a release agent for a die casting machine, which does not cause a decrease in the temperature of the die, even though the release agent can be uniformly applied to the die, and its method. It is intended to provide a device.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a method for controlling the discharge pressure of a release agent composed of a water-soluble inorganic salt or the like discharged from a release agent discharge port. The release agent is applied to the inner surface of the mold by a plurality of spray nozzles that atomize and spray the release agent at a pressure equal to or less than １ ／ of the ejection pressure of the air ejected from the atomization air ejection port provided around the nozzle. A method of spraying a release agent for a die-casting machine is the invention of claim 1, wherein the discharge pressure of the release agent is 0.01 to 0.1 MPa.
A second aspect of the present invention is a method of spraying a release agent for a die-casting machine in which the pressure of air is 0.2 to 0.3 MPa.
The method of spraying a release agent for a die casting machine having a thickness of about 0.1 μm is defined as the invention of claim 3. The method of claim 1, wherein the particle size of the release agent attached to the inner surface of the mold is about 100 μm. The method of spraying a mold release agent according to claim 4, wherein the discharge pressure of a release agent such as a water-soluble inorganic salt discharged from the release agent discharge port is reduced by atomizing air provided around the release agent discharge port. A die-casting device in which a plurality of spray nozzles for atomizing and spraying a release agent at a pressure equal to or less than １ ／ of the ejection pressure of air ejected from an ejection port are attached to the front and back of a spray unit which can freely enter between opened molds. the machine for the release agent spray device and the invention of claim 5, characterized in that in the invention of claim 5, a die casting machine mold release agent spray device provided with air nozzles for spraying range restricting forward sides of the spray nozzle according to claim 6 It is an invention.

[0005]

Next, a preferred embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, reference numeral 1 denotes a die casting machine. The die casting machine 1 includes a movable plate 2 having a male mold 2a attached thereto, a fixed plate 3 having a female mold 3a attached thereto, and a male mold 2 having the movable plate 2 attached thereto.
a mold clamping cylinder 4 for matching a with the female mold 3a, and an injection cylinder 5 for injecting the molten metal into the matched mold.
Consists of The temperature of the male mold 2a and the female mold 3a is controlled so as to be about 90 to 150 ° C. required for die casting.

Reference numeral 6 denotes a spray unit for spray-coating a mold release agent onto a mold. The spray unit 6 is supported by a robot arm and can freely enter between the opened male mold 2a and female mold 3a. The release agent is sprayed on the inner surfaces of the male mold 2a and the female mold 3a. Further, as shown in FIG. 3, the plurality of spray nozzles 7 attached to the front and back of the spray unit 6 are arranged so as to spray the entire vertical width of the inner surfaces of the male and female molds at a constant width. The release agent can be applied to the entire inner surface of the mold only by scanning in the lateral direction. Further, as shown in FIG. 4, the spray nozzle 7 includes a release agent discharge port 7a for discharging the release agent and an annular atomizing air jet port 7b provided around the release agent discharge port 7a. The discharge pressure of the release agent discharged from the release agent discharge port 7a is set to be equal to or less than 1/2 of the ejection pressure of the air, and the release agent discharged is discharged from the surrounding atomized air outlet 7b. Fine particles are formed by air at a pressure higher than the pressure. At this time, the discharge pressure of the release agent is set to 0.01 to 0.1 MPa, and the ejection pressure of air is set to 0.2 to 0.3 MPa. Release pressure of release agent is set to 0.0
The reason for setting the pressure to 1 to 0.1 MPa is that a suction force acts on the release agent by the air pressure more than doubled from the surroundings, so that the lower limit of the discharge pressure is such that the release agent can be discharged from the release agent discharge port 7a. The reason why the upper limit of the discharge pressure is set to 0.1 MPa is that by setting the discharge pressure to a low pressure, the design of piping and the like becomes easy, and the pressure device can be made inexpensive. The reason why the air ejection pressure is 0.2 to 0.3 MPa is as follows.
It is sufficient that the discharge pressure of the release agent is twice or more. However, if the pressure is too high, it becomes difficult to design piping and the like, and the pressurizing device becomes expensive. The discharging device discharges the release agent at a discharge pressure of 0.1 MPa from the release agent discharge port 7a having a diameter of 0.8 mm, and ejects 0.25 MPa from the atomized air discharge port 7b around the release agent discharge port 7a. Air was blown out by pressure. At this time, the discharge particle size of the release agent could be set to an ideal value of about 30 μm. When the release agent thus formed into fine particles adheres to a mold 200 to 400 mm away,
The fine particles are formed into thin, flat adhered particles of about 100 μm due to the effect of the surfactant, so that the release agent is instantaneously crystallized by the temperature of the mold to form a coating of the release agent.

The release agent used at this time is sodium carbonate,
It comprises a water-soluble inorganic salt such as potassium chloride and a surfactant such as ethers or esters. The reason for using a water-soluble inorganic salt is that the ionization tendency is higher than that of the molten metal, it does not react with the molten metal, there is no carbonization, gasification, and black smoke generated by thermal decomposition, no foreign substances adhere to the die-cast product, and the drainage load is small. It is. In addition, the surfactant is used to reduce the splash of the water-soluble inorganic salt and to enhance the adhesion to the mold.

Reference numeral 8 denotes a spray range regulating air nozzle provided on both front sides of the spray nozzle 7. The spray range regulating air nozzle 8 is used to discharge a release agent sprayed in a conical shape through a release agent discharge port 7a. 60-80 m width as shown in FIG.
m, and a rectangular spray pattern having a length of 160 to 180 mm.
It does not overlap with the spray pattern. Since there is no overlap, the release agent can be applied evenly. Further, since the release agent can be applied evenly, the release agent can be applied uniformly even when the spray unit 6 is reciprocated right and left by the robot arm to perform the overcoating.

[0010] In the above-mentioned structure, before performing die casting, the movable plate 2 is retracted by operating the mold clamping cylinder 4 of the die casting machine 1 to open the male mold 2a and the female mold 2b. In this state, the spray unit 6 is opened by the robot arm with the male mold 2a and the female mold 2b.
Then, the release agent is sprayed from a plurality of spray nozzles 7 attached to the front and back of the spray unit 6.
At this time, the release agent sprayed from the spray nozzles 7 is sprayed by the spray range regulating air nozzles 8 provided on both sides in front of each spray nozzle 7 to have a width of 60 to 80 mm and a length of 320 to 360 m.
m (by the upper and lower spray nozzles) has a rectangular spray pattern with almost no overlap, so that once the spray unit 6 is scanned once, the release agent is spread over the entire inner surfaces of the male mold 2a and the female mold 2b. Can be uniformly applied.

The spraying of the release agent by the spray nozzle 7 is carried out from the release agent discharge port 7a having a diameter of 0.8 mm by 0.1 MPa.
The release agent discharged at the pressure of a is discharged from the atomizing air outlet 7b provided around the release agent discharge port 7a by 0.25 MPa.
Of compressed air, the discharge particle size is about 30
The fine particles having a diameter of μm are sprayed on the inner surfaces of the male mold 2a and the female mold 2b. Then, the sprayed release agent particles having a particle size of about 30 μm adhere to the mold and become thin, flat adhered particles of about 100 μm due to the surfactant, so that the mold is more densely released than the spray pattern on the inner surface of the mold. The agent will be deposited. In addition, since the adhered particles are extremely thin and flat, they are instantaneously crystallized by the temperature of the mold set at 90 to 150 ° C. Further, if necessary, the spray unit 6 may be scanned a plurality of times to apply the release agent repeatedly.

[0011]

According to the present invention, as apparent from the above description, the discharge pressure of the release agent composed of a water-soluble inorganic salt or the like discharged from the release agent discharge port is provided around the release agent discharge port. 1/2 of the jet pressure of the air jetted from the atomized air jet port
Since the release agent is applied to the inner surface of the mold by a plurality of spray nozzles that atomize and spray the release agent as below, stable spraying is possible and it is sprayed and collides with the inner surface of the mold The resulting fine particles become thin flat adhered particles due to the surfactant, so that the release agent is applied more densely than the spray pattern. Moreover, the adhered particles are instantaneously crystallized by the heat of the mold whose temperature is set, and a release agent film is formed on the inner surface of the mold. In addition, since the crystallization of the release agent is performed instantaneously, the release agent does not flow off, and the release agent does not flow down even if the coating is repeated two to three times. Furthermore, by setting the discharge pressure of the release agent to 0.01 to 0.1 MPa and the ejection pressure of air to 0.2 to 0.3 MPa as described in claim 2, the release agent becomes fine particles of a preferable size. In addition to being atomized, the spray can be stabilized. As in claim 3,
By setting the ejection particle size of the release agent to about 30 μm, the adhesion of the release agent can be optimized. As described in claim 4, the particle size of the release agent attached to the inner surface of the mold is about 100.
By setting the thickness to μm, the coating of the release agent can be made ideal. By providing a plurality of spray nozzles on the front and back of the spray unit as described in claim 5, it is possible to form a release agent film on the entire inner surface of the mold only by scanning the spray unit once, thereby improving productivity. it can. By providing the spray range regulating air nozzles on both front sides of the spray nozzle as in claim 6, a spray pattern without overlapping can be formed, so that a uniform release agent film can be efficiently formed in a mold. It has various advantages such as being able to be formed on the inner surface. Therefore, the present invention greatly contributes to the development of the industry as a method and an apparatus for spraying a release agent for a die casting machine which have solved the conventional problems.

[Brief description of the drawings]

FIG. 1 is a side view showing a preferred embodiment of the present invention.

FIG. 2 is a side view of a spray device used in a preferred embodiment of the present invention.

FIG. 3 is a front view of a spray device used in a preferred embodiment of the present invention.

FIG. 4 is a partially cutaway plan view of a spray nozzle used in a preferred embodiment of the present invention.

FIG. 5 is a partially cutaway front view of a conventional spray nozzle.

[Explanation of symbols]

 6 spray unit 7 spray nozzle 7a release agent discharge port 7b air jet port 8 air nozzle for spray range control

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B22D 17/20 B22D 17/20 D B29C 33/58 B29C 33/58

Claims (6)

[Claims] 1. A discharge pressure of a release agent composed of a water-soluble inorganic salt or the like discharged from a release agent discharge port is ejected from an atomizing air outlet provided around the release agent discharge port. A method for spraying a release agent for a die-casting machine, characterized in that the release agent is applied to the inner surface of a mold by a plurality of spray nozzles that atomize and spray the release agent at a pressure equal to or less than 1/2 of the air ejection pressure. 2. A discharge pressure of a release agent of 0.01 to 0.1 MPa.
The method for spraying a release agent for a die-casting machine according to claim 1, wherein a is set at a and the jet pressure of air is 0.2 to 0.3 MPa. 3. The method for spraying a release agent for a die-casting machine according to claim 1, wherein the discharge particle size of the release agent is about 30 μm. 4. The method according to claim 1, wherein the particle size of the release agent attached to the inner surface of the mold is about 100 μm. 5. A method for controlling the discharge pressure of a release agent such as a water-soluble inorganic salt discharged from a release agent discharge port by means of air ejected from an atomizing air outlet provided around the release agent discharge port. 1 of the jet pressure
A plurality of spray nozzles for atomizing and spraying a release agent at a ratio of not more than / 2 are mounted on the front and back of a spray unit capable of freely entering between the opened molds. . 6. The release agent spraying device for a die casting machine according to claim 5, wherein air nozzles for controlling a spraying range are provided on both front sides of the spraying nozzle.