JP2005342783A - Method for spraying releasing agent, and spray unit for die casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spray unit for die casting capable of spraying a slight amount of an oily releasing agent on the inner surface of a die and utilizing an existing facility. <P>SOLUTION: The spray unit 1 is provided with: a unit main body 18 attached to a releasing agent spraying apparatus in a die casting machine; an annular releasing agent tube 20, in which its one end part is connected to the unit main body 18 and a releasing agent passage 19 communicatable to the oily releasing agent 13 is formed; a double spray tube part 2, in which the releasing agent tube 20 is housed in an in-tube space 21, and which has an air tube 25 formed so as to surround the outer periphery of the releasing agent tube 20 with an air passage 24 passable of press-feeding air 16 supplied from the press-feeding air supply device between the inner wall 22 and the outer wall 23 of the releasing agent tube 20 and has a double tube structure by the releasing agent tube 20 and the air tube 25; and a nozzle part 3, which is attached to another end part of the double spray tube part 2 and has a nozzle hole 26 connected to the releasing agent passage 19 and the air passage 24. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mold release agent spraying method and a die casting casting spray unit, and in particular, a mold release that can be sprayed onto the inner surface of a die casting mold while minimizing the spray amount of an oil release agent. The present invention relates to a mold spraying method and a die casting casting unit.

  Conventionally, in a casting process of die casting, a step of spraying or applying a release agent to the inner surface of a mold is provided before injecting a high-temperature molten metal into the mold cavity. This mold release agent is used for the purpose of preventing the mold inner surface from being damaged by high-temperature molten metal heat and facilitating mold separation when a die-cast molded product molded after molten metal injection is taken out of the mold. ing. Here, the mold release agent is a water-soluble mold release agent formed by an oil-based mold release agent mainly composed of oils such as animal and vegetable oils or mineral oils, and a water-soluble inorganic compound such as silicone, sodium carbonate, or potassium chloride. It can be roughly divided into two types: agents. Here, the oil-based mold release agent is sprayed onto the inner surface of the mold, whereby a film of the oil-based mold release agent can be uniformly and quickly formed on the inner surface of the mold according to the surface tension. A mold effect can be produced. Therefore, in the conventional die casting process, the use of this oil-based release agent has become the mainstream.

  However, if the amount of spray on the inner surface of the mold is excessive, the oil-based mold release agent described above may cause the heated oil-based mold release agent to gas out of the cavity when the molten metal is injected into the mold cavity. There was a case. For this reason, the gas generated in the cavity may affect the quality of the die-cast product to be molded. In addition, oil-based mold release agents have an adverse effect on pollution and the natural environment if they are discharged to the outside as they are, so there are emission regulations, and usually they are discharged after waste liquid treatment by chemical or physical methods. There was a need. Therefore, although it has an excellent release agent effect due to the difficulty of handling and waste liquid, at present, the use of oil-based release agents is avoided and gradually switched to the use of water-soluble release agents mainly composed of inorganic compounds There are many cases.

  Even when the spray amount (adhesion amount) on the inner surface of the mold becomes excessive, this water-soluble mold release agent is less likely to gasify in the cavity like the oil-based mold release agent described above, and is water-soluble. Therefore, waste liquid treatment after use can be easily performed as compared with oil-based release agents. Here, when an example of the spray unit 100 of the type that sprays the water-soluble release agent is schematically shown in FIG. 6, the release agent supply source 102 of the water-soluble release agent 101 and the water-soluble release agent 101 are A unit main body 105 connected to a pressurized air supply source 104 that supplies a pressurized air 103 for spraying using air pressure, a circular spray pipe 106 connected to the unit main body 105, and one end of the spray pipe 106. The nozzle portion 107 is mainly configured. In the spray unit 100, the release agent supply source 102 and the pressure air supply source 104 described above are connected together in the vicinity of the connection portion of the spray tube 106 installed in the unit main body 105. Then, the water-soluble release agent 101 and the compressed air 103 supplied from the respective supply sources 102 and 104 are mixed while passing through the in-pipe space 108 of the spray tube 106 from the vicinity of the connection portion of the unit body 105 of the spray tube 106. , And sent out toward the nozzle port 109 of the nozzle unit 107. Then, the gas-liquid mixture 110 of the water-soluble release agent 101 and the pressurized air 103 that has reached the nozzle port 109 is ejected from the nozzle port 109 to the outside, and the die inner surface (not shown) of the die casting mold. Had been sprayed against. At this time, for example, there are some sprayed with about 200 cc of water-soluble release agent 101 per second, although it varies depending on the area to be sprayed and the inner surface shape of the mold.

  The above prior art is publicly implemented, and the applicant does not particularly know the document describing the prior art at the time of filing this application.

  However, the water-soluble release agent has a defect that the adhesion to the inner surface of the mold is inferior to that of the oil release agent. Therefore, as described above, it is difficult to obtain a sufficient release agent effect unless a water-soluble release agent of about 200 cc is applied per second. In particular, when the mold temperature of the mold heated in advance during the injection of the molten metal exceeds 200 ° C. or more, the sprayed water-soluble mold release agent becomes easy to play on the inner surface of the mold and becomes mottled on the inner surface of the mold. In some cases, a water-soluble mold release agent adhered. As a result, it is impossible to form a uniform film with a water-soluble mold release agent, and injecting molten metal into the cavity in such a state may cause mold erosion, deterioration of mold release, and die-cast products. May cause problems such as quality degradation.

  Further, as described above, the water-soluble release agent is formed mainly of an inorganic compound such as silicone resin, sodium carbonate, potassium chloride. For this reason, some of these solidify and accumulate in the form of a residue. As a result, debris accumulates inside the spray tube, causing the gas-liquid mixture of the water-soluble mold release agent and the pressurized air to flow out smoothly, or causing debris to adhere to the inner surface of the mold, thereby deteriorating the surface quality of the die-cast product. There was a thing. As a result, it is necessary to frequently clean the inside of the spray tube and the nozzle part and the inner surface of the mold, and the maintenance cost required for such cleaning and the like is often required as compared with the oil-based release agent. Further, the stains of the water-soluble release agent scattered around the die casting machine may be particularly severe.

  In addition, as described above, the water-soluble release agent is often sprayed in a large amount in order to obtain a sufficient release agent effect. As a result, when such a water-soluble mold release agent is sprayed onto a mold that has been preheated before the injection of the molten metal, the mold temperature in the preheated state may change and temperature unevenness may occur. For this reason, the quality of the die-cast product is affected, and a more drastic temperature change is received for each injection, so that the life of the mold may be reduced. Furthermore, although the waste liquid treatment of the water-soluble mold release agent that remains after being sprayed in a large amount is not as difficult as the oil-based mold release agent described above, the amount of use is larger than that of the oil-based mold release agent, so the troublesome processing work Sometimes imposed on the person.

  By the way, in the die casting machine in which water-soluble release agents have become mainstream due to the various problems described above, there are many cases in which oil-based release agents having excellent adhesion to the inner surface of the mold are used again. Therefore, there has been a demand for the development of a device (a spray unit) capable of spraying the minimum necessary amount of oil-based mold release agent on the inner surface of the mold. Further, as described above, a die casting machine currently used is often provided with a release agent spraying device for spraying a water-soluble release agent, and these existing devices can be used as much as possible. There has been a demand for a spray unit for spraying a release agent that can be diverted to reduce the cost of equipment change.

  Therefore, in view of the above circumstances, the present invention provides a release agent spraying method capable of spraying a minute amount of an oil release agent on the inner surface of a mold and diverting existing equipment, and a die casting casting spray unit used therefor. Is an issue.

  In order to solve the above-mentioned problems, the release agent spraying method of the present invention is described as follows. “A double release agent passage in which an oil-based release agent can flow and an air passage in which pressurized air can flow are formed independently. The oily material with a weak pumping pressure that does not eject from the nozzle port of the nozzle part connected to the double spray pipe part through the release agent passage of the double spray pipe part configured to exhibit a pipe structure A weakly supplying step of an oil-based mold release agent, a proximity step of bringing the nozzle port close to the inner surface of the mold of the mold that has been opened, and the pumping pressure via the air passage of the double spray pipe section. A pressure-feeding air ejecting step for ejecting from the nozzle port adjacent to the inner surface of the mold by the proximity step, and utilizing the suction force generated when the pressured air is ejected from the nozzle port, An oil-based mold release agent is sprayed on the inner surface of the mold " It is configured in La main.

  Therefore, according to the release agent spraying method of the present invention, in the double spray tube portion and the nozzle portion, the passages (air passage, release agent passage) through which the oil-based release agent and the pressurized air flow are independent of each other. It is formed and both do not mix up to the nozzle opening of the nozzle part. Moreover, the weak pressure feed pressure which only makes an oil-based mold release agent reach the nozzle mouth of a nozzle part by the oil-based mold release agent weak supply process is supplied. Then, in this state, the nozzle port of the nozzle portion is brought close to the inner surface of the mold to be sprayed by the proximity process, and the pressurized air ejecting means is operated to eject the pressurized air from the nozzle port. At this time, the pressurized air reaches the nozzle opening through a path (passage) different from that of the oil release agent through the air passage of the double spray pipe part. And the oil-based mold release agent currently supplied to the nozzle port is attracted | sucked to the exterior of a nozzle port by the negative pressure which arises when pumping air is ejected from a nozzle port. As a result, the oil-based mold release agent can be sprayed onto the inner surface of the mold together with the pressurized air, and the oil-based mold release agent can be sprayed.

  On the other hand, the spray unit for die casting of the present invention is “a die casting casting unit used in the release agent spraying method according to claim 1, wherein the release agent supplying means supplies an oil release agent, And a unit main body installed in a release agent spraying device connected to a pressurized air supply means for supplying pressurized air for spraying the oil release agent, and one end connected to the unit main body, and the release agent supply means A release agent pipe formed with a release agent passage through which the oil-based release agent can be supplied, and an inner wall of the release agent pipe and an outer wall of the release agent pipe. An air pipe in which an air passage through which the compressed air supplied from the pressurized air supply means can flow is formed, and the release agent passage and the air passage have an independent double pipe structure. A double spray tube portion configured, and the double spray tube portion A nozzle part having a nozzle port installed at an end and communicating with the release agent passage and the air passage, and the oil release agent supplied to the nozzle port by the release agent supply means, It is mainly comprised from what sprays on the metal mold | die inner surface using the attraction | suction force which arises when the said compressed air is ejected from the said nozzle opening.

  Here, the shape of each of the release agent pipe and the air pipe of the double spray pipe portion having a double pipe structure is not particularly limited, but there is no disturbance in the flow of the oil release agent and the pumped air. As described above, it is desirable to use a circular pipe having a smooth inner peripheral surface having a curved shape. Moreover, as the tube material constituting these, for example, a metal tube made of stainless steel or copper, or a resin tube such as vinyl chloride resin can be appropriately used. Furthermore, the release agent pipe corresponding to the inner pipe and the air pipe corresponding to the outer pipe may use the same type of material, or may use different types of materials. And, by forming such a double pipe structure in which the release agent pipe is accommodated in the inner space of the air pipe, a release agent passage through which the oil-based release agent can flow is formed inside the release agent pipe. On the other hand, an air passage through which pressurized air can flow is formed between the outer wall of the release agent pipe and the inner wall of the air pipe. As a result, the oil-based mold release agent and the compressed air are circulated independently in the double spray tube portion. Furthermore, in other words, both of them will not be in a state of being mixed up to the nozzle opening of the nozzle part described later.

  Further, the unit main body is separated by a release agent supply means (equivalent to a release agent tank and a pressure feed pump) for supplying an oil release agent sprayed on the inner surface of the mold, and a pressurized air supply means (e.g. a compressor is equivalent). It is connected via a mold spraying device. The release agent supply means delivers the oil release agent to a nozzle port provided at the tip of the nozzle portion, and sprays the oil release agent from the nozzle port of the nozzle portion toward the inner surface of the mold. Not enough pressure to give it. In other words, the release agent supply means is only for delivering pressure to the nozzle opening by applying pressure, and the value of the pressure feed pressure is set to a value close to zero although it is slightly positive. Further, the oil release agent is supplied again to the nozzle opening so as to compensate only for the consumption of the oil release agent sprayed to the outside by the action of the compressed air described later.

  On the other hand, the pressurized air supply means uses an existing air supply device such as the above-described compressor, and can spray the pressurized air vigorously toward the outside of the nozzle portion through the air passage and the nozzle portion. It is possible. That is, the pumping air supplied by the pumping air supply means is applied with a sufficient pumping pressure for spraying the oil release agent toward the inner surface of the mold.

  Further, the spray unit for die casting of the present invention is attached to a die casting machine used in ordinary die casting, and the die casting machine has a mold for performing mold opening and closing operations. The apparatus includes basic devices such as an opening / closing device, an injection device for injecting a high-temperature molten metal into a cavity of a mold, and a control device for controlling these various devices. The control device is connected to the die casting casting unit of the present invention, and includes a function for controlling the spray unit, and controls the pumping pressure and pumping timing of the pumping air by the pumping air supply means, In order to adjust the spray amount of the mold release agent on the inner surface of the mold, and to bring the nozzle portion closer to the inner surface of the mold, control is performed to move the nozzle portion of the spray unit for die casting by the moving means. Yes. As a result, the oil release agent can be sprayed by bringing the nozzle portion close to the inner surface of the mold while the mold is open, while the mold is closed and the molten metal is injected into the cavity. In some cases, it can be moved to a position away from the mold.

  Therefore, according to the spray unit for die casting of the present invention, each passage of the double spray pipe portion configured to have a double pipe structure by the release agent pipe and the air pipe is provided with the oil release agent and the pressurized air. Is distributed in an independent state and is sent to the nozzle opening of the nozzle portion. At this time, although the oil-based release agent is maintained in a state where it is delivered to the nozzle port of the nozzle portion by the release agent supply means, strong pressure that can be sprayed from the nozzle port toward the outside of the nozzle portion is Not added. On the other hand, the pressure-feed air supply means is in a standby state so that the pressure-feed air does not flow through the air passage until the pressure-feed timing in accordance with an instruction from the control device of the die casting machine. Then, when the die casting machine is controlled and the mold is opened and the inner surface of the mold is exposed to the outside, the die casting casting unit is moved by the moving means, and the nozzle port of the nozzle portion is moved to the inner surface of the mold. Directed to. Then, the pressure air supply means is operated, and the pressure air is pressure-fed through the air passage to the nozzle port of the nozzle portion.

  Thereafter, the compressed air that has reached the nozzle portion is instantaneously ejected from the nozzle port toward the outside. At this time, the oil release agent is supplied to the nozzle opening as described above. Therefore, a part of the initial oil-based mold release agent present in the vicinity of the nozzle opening is scattered to the outside along with the flow of jetted air. Furthermore, when the pressurized air is ejected from the nozzle port, the pressure in the vicinity of the nozzle port decreases with the flow of the pressurized air. That is, a negative pressure state is created. Thereby, the oil-based mold release agent supplied to the nozzle opening is sucked to the outside of the nozzle portion by the negative suction force. And the oil-based mold release agent which came out of the nozzle opening moves toward the inner surface of the mold along the flow of the pressure air, and when it reaches the inner surface of the mold, it adheres to the inner surface of the mold due to surface tension. This makes it possible to spray the oil-based mold release agent on the inner surface of the mold only by the pumping pressure of the pumping air. That is, it is not necessary to mix an aqueous or oil-based release agent in advance in a spray tube or the like, and to spray from the nozzle port in the state of a gas-liquid mixture in which gas and liquid are mixed. The value of can be kept low. Furthermore, since the negative pressure of the pumped air is used, a negative pressure is generated at the nozzle opening even by a very small air flow. It is possible to reduce significantly compared to the agent. Furthermore, oil-based release agents are easier to form on the inner surface of the mold due to surface tension characteristics than water-soluble release agents, so the amount of oil-based release agent that adheres to the inner surface of the mold is the minimum required amount. It is possible to achieve an effect of a sufficient oil-based mold release agent in a state of being suppressed to a low level.

  Further, the spray unit for die casting of the present invention has the above-mentioned configuration, “The unit main body is detachably attached to the release agent spray device, and the release agent spray device is the mold. It is characterized by being attached to a die casting machine that sprays a water-soluble release agent on the inner surface. "

  Therefore, according to the die casting casting unit of the present invention, the unit main body to which the double spray pipe portion is connected is formed to be detachable from the release agent spraying device of the die casting machine. Further, as the release agent spraying device, a device provided in a die casting machine using an existing water-soluble release agent can be used. As a result, the spray unit for the water-soluble mold release agent is removed from the existing mold release agent spraying device, and the die casting casting unit for the oil-based mold release agent of the present invention is attached, and the oil mold release agent is attached to the inner surface of the mold. By carrying out the spraying process, it is possible to easily convert to a spraying of a small amount of oil-based mold release agent without making significant changes to the die-casting machine while effectively utilizing existing equipment. .

  On the other hand, the spray unit for die casting of the present invention has, in addition to the above configuration, “the pressure of the pressured air supplied from the pressured air supply means is set to 0.2 MPa or more and 0.5 MPa or less” It does not matter.

  Therefore, according to the spray unit for die casting of the present invention, the pumping pressure of the pumping air supplied by the pumping air supply means is set to 0.2 MPa or more and 0.5 MPa or less. Here, when the existing water-soluble release agent is used, the water-soluble release agent and the pressurized air for pressure feeding are mixed in advance in the space in the pipe of the spray pipe part (see FIG. 6), and then the tip of the nozzle part. Had to erupt from. As a result, as in the die casting casting unit of the present invention, a sufficient amount of water-soluble release agent is sprayed on the inner surface of the mold as compared with the pressure for feeding only the pressure air from the nozzle portion, In order to make it adhere, it was necessary to set the pressure of the pressurized air higher by the weight of the water-soluble release agent contained in the pressurized air. In the case of a conventional water-soluble release agent, the value of the pumping pressure of such pumping air generally depends on the spray target and spray area, and further on the type of the water-soluble release agent, but is generally between 0.5 MPa and 0.7 MPa. Was set relatively high.

  However, the oil-based mold release agent can be sprayed by using the suction force generated by the negative pressure of the pumped air of the present invention, and the pumping pressure is lower than that in which the water-soluble mold release agent is directly pumped. It becomes possible to set. As a result, the amount of the oil-based mold release agent attached to the inner surface of the mold can be improved, and the oil-based mold release agent can have a sufficient effect, and the mold casting machine can be attached to the periphery of the die-casting machine. Scattering of the oil release agent can be greatly reduced. As a result, maintenance such as cleaning can be simplified, and the amount of oil-based release agent used can be suppressed. In addition, when the pumping pressure is less than 0.1 MPa, the negative pressure suction force generated by the pumping air does not function sufficiently, and the oil-based release agent cannot be completely sprayed from the nozzle port of the nozzle part, The amount of oil release agent on the inner surface is not sufficient. As a result, the effect of the oil release agent cannot be obtained. On the other hand, when the value of the pumping pressure of the pumping air exceeds 0.5 MPa, the above-described problems caused by the excessive oil-based release agent or water-soluble release agent occur, and a small amount of oil-based release agent is generated. The advantages of the present invention for spraying are lost.

  Furthermore, the spray unit for die casting casting of the present invention has, in addition to the above-described configuration, “the double spray pipe part is a circular tubular release agent pipe having a pipe diameter of 1.5 mm or more and 3.5 mm or less, And a circular tubular air tube having a tube diameter of 5.0 mm or more and 7.0 mm or less.

  Therefore, according to the spray unit for die casting of the present invention, the double spray pipe part is composed of a release agent pipe and an air pipe each formed in a circular pipe shape, and each pipe diameter. However, the release agent tube is set to 1.5 mm or more and 3.5 mm or less, more preferably 2.0 mm or more and 3.0 mm or less, and the air tube is set to 5.0 mm or more and 7.0 mm or less, more preferably 5 mm. It is set to not less than 5 mm and not more than 6.5 mm. Here, with respect to the pipe diameter of the release agent pipe arranged in the vicinity of the center in the inner space of the air pipe, the distance between the air passages through which the pressurized air can flow (the inner wall of the air pipe and the release agent pipe If the space between the pipe outer walls is too wide), the volume ratio of the pumped air and oil release agent ejected from the nozzle port is overwhelmingly higher for the pumped air, and the volume ratio of the pumped air is oily. The release agent is hardly sprayed. As a result, the amount of oil-based release agent attached to the inner surface of the mold may not be sufficient, and in order to make the amount of adhesion sufficient, it is necessary to lengthen the pumping time of the pumping air. Thereby, the time of the spraying process of the oil-based mold release agent with respect to the inner surface of the mold was lengthened, and the working time was expected to be longer than before. On the other hand, when the width is too narrow, the pumping amount of the pumping air becomes small, and a suction action for sucking the oil release agent at the nozzle opening by the negative pressure suction force cannot be obtained sufficiently. Therefore, the spray unit for die casting of the present invention sets the pipe diameter of the release agent pipe and the pipe diameter of the air pipe within the predetermined ranges, respectively, so that the pumping pressure of the pumping air and the spray amount of the oil release agent are set. It is possible to maintain an appropriate balance so that an appropriate oil-based release agent can be adhered to the inner surface of the mold.

  According to the release agent spraying method and the die casting casting unit of the present invention, the release agent passage of the oil release agent and the air passage of the pressurized air constitute a double spray pipe portion exhibiting a double tube structure. Thus, the oil-based mold release agent can be sucked out of the nozzle portion by using the negative pressure suction force generated by the pumped air and sprayed on the inner surface of the mold. Thereby, the spraying amount of the oil release agent can be suppressed, the excessive oil release agent can be prevented from adhering to the inner surface of the mold, and problems due to gasification of the oil release agent can be eliminated. Furthermore, because the unit body can be used for existing water-soluble release agents, die casting for spraying a small amount of oil-based release agents without major changes to existing die casting machine equipment. It can be converted into a casting spray unit.

  Hereinafter, a spray unit 1 for die casting (hereinafter, simply referred to as “spray unit 1”) according to an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is an explanatory diagram showing a schematic configuration of a die casting machine 5 in which the spray unit 1 of the present embodiment is installed, and FIG. 2 is a configuration of the double spray pipe portion 2 and the nozzle portion 3 of the spray unit 1. 3 is an enlarged cross-sectional view, FIG. 3 is a partially cutaway perspective view showing the configuration of the double spray tube portion 2 and the nozzle portion 3, and FIG. 4 is a front view showing the configuration of the nozzle portion 3. These are explanatory drawings which show an example of use of the spray unit 1.

  Here, the die-casting machine 5 used in the present embodiment is installed in a release agent spraying device 6 in which the spraying unit 1 is installed, and a machine base 7, and includes a male mold 8 a and a female mold 8 b. The mold 8 is separable into two mold surfaces 9a and 9b that face each other with the mold surfaces 9a and 9b spaced apart from each other, and the mold inner surface 4 is exposed to the outside (see FIG. 5A). ) And the mold surfaces 9a and 9b are in close contact with each other, and a mold 8 is formed between the “mold closed state” (see FIG. 5B) in which a cavity into which a high-temperature molten metal (not shown) is injected is formed. A mold opening / closing device 10 that performs an opening / closing operation in the left-right direction (arrow A direction in FIG. 1), a molten metal injection device 11 that injects a molten metal into the cavity of the mold 8 that is closed, and molds a die-cast product, Release agent spray device 6, mold opening / closing device 10, and molten metal spray described above And and a control unit 12 for controlling various operations of the die casting machine 5 of the device 11 or the like is mainly constituted.

  More specifically, the spray unit 1 of the present embodiment is detachably attached to the release agent spray device 6 of the die casting machine 5, and the release agent spray device 6 is an existing water-soluble release agent. The type that uses the agent is diverted. In other words, it was converted to a die casting machine 5 of a type that uses an oil-based mold release agent while making full use of the equipment assets of a die cast machine for spraying a water-soluble mold release agent and without making significant improvements and design changes. is there.

  And this mold release agent spraying apparatus 6 is the nozzle part 3 (spraying unit 1) of the spraying unit 1 of this embodiment with respect to each mold inner surface 4 of the mold 8 which is in the mold open state by the mold opening and closing device 10. The details of the configuration of the spraying unit 1 are set close to each other, the spraying position AP (see FIG. 5A) for spraying the oil-based mold release agent 13 from the nozzle part 3, and the spraying unit 1 when the molten metal is injected are molds. And a nozzle moving device 14 that moves in the vertical direction (in the direction of arrow B in FIG. 1) between the separated positions BP (see FIG. 5 (b)) that are separated from the vicinity of 8 and retracted. A release agent supply device 15 for supplying an oil-based release agent 13 for spraying from the nozzle portion 3 and a pressurized air supply device 17 for supplying pressurized air 16 for spraying are mainly configured. Yes.

  Here, the release agent supply device 15 can divert the release agent tank and the release agent pump as they are when the existing water-soluble release agent is used, similarly to the release agent spraying device 6 described above. Further, the compressed air supply device 17 can use a compressor or an air supply device stretched around in a die casting foundry. The release agent supply device 15 corresponds to the release agent supply means in the present invention, and the pressurized air supply device 17 corresponds to the pressurized air supply means in the present invention. Moreover, in this embodiment, what mixed several kinds of mineral oil by the predetermined | prescribed compounding ratio is used as the oil-based mold release agent 13. FIG. The blending ratio of the oil-based release agent 13 is appropriately changed depending on the temperature environment at the time of die casting and the type of die cast product to be molded.

  The spray unit 1 according to the present embodiment includes a unit body 18 connected to the release agent supply device 15 and the pressurized air supply device 17 via the release agent spray device 6, and one end connected to the unit body 18. The release agent passage 19 through which the oil release agent 13 supplied from the release agent supply device 15 can flow is formed in the tube, and the release agent tube 20 has a tube shape. The release agent pipe 20 is housed in the pipe inner space 21 and supplied from the pressure air supply device 17 between the pipe inner wall 22 and the pipe outer wall 23 of the release agent pipe 20. The air passage 24 through which the compressed air 16 can flow has an air tube 25 formed so as to surround the outer periphery of the release agent tube 20, and the release agent tube 20 and the air tube 25 form a double tube structure. Double spray pipe part 2 configured as above and double spray pipe part 2 It is To設 the other end, are mainly configured by including a nozzle portion 3 having a nozzle opening 26 connected with the release agent passage 19 and air passage 25.

  Here, in the release agent tube 20 of the double spray tube portion 2, the tube outer wall 23 of the release agent tube 20 and the tube inner wall 22 of the air tube 25 are brought into contact with approximately the center of the inner space 21 of the air tube 25. It is fixed in a state of being accommodated so that there is no (see FIGS. 2 and 3). Here, in the present embodiment, a copper circular pipe having a pipe diameter of 6 mm is used for the air pipe 25, while a copper circular pipe having a pipe diameter of 2.5 mm is used for the release agent pipe 20. . And by exhibiting this double pipe structure, the oil-based mold release agent 13 supplied from the mold release agent supply device 15 and the pressure-feed air 16 supplied from the pressure-feed air supply device 17 are supplied to the inside of the double spray pipe portion 2. Are distributed independently without mixing between the release agent passage 19 and the air passage 24 formed concentrically, respectively, and sent to the nozzle port 26 of the nozzle portion 3. At this time, the oil release agent 13 supplied from the release agent supply device 15 is only applied with a very weak release agent supply pressure, and the oil release agent 13 passes through the release agent passage 19. Only a weak pressure close to zero for reaching the nozzle opening 26 of the nozzle portion 3 is applied. That is, in other words, no strong pressure is applied so that the oil release agent 13 can be sprayed from the nozzle opening 26 onto the inner surface 4 of the mold.

  Further, the unit main body 18 is detachably connected to the release agent spraying device 6. At this time, the connection parts of the unit main body 18 and the release agent spraying device 6 are respectively connected via the release agent supply device 15 and the pressurized air supply device 17 of the release agent spraying device 6, and the unit main body 18 and the unit main body 18. The release agent passage 19 of the release agent tube 20 and the air passage 24 of the air tube 25 are connected in a liquid-tight state and an air-tight state, respectively (not shown). As a result, leakage of the oil release agent 13 from the release agent passage 19 to the air passage 24, leakage of the pressurized air 16 from the air passage 24 to the release agent passage 19, and pressurized air 16 from the air passage 24 to the outside. Connected so that there is no leakage. In order to maintain such an airtight state and a liquid tight state, conventionally known seal members, packing members, O-rings and the like for preventing gas / liquid leakage are appropriately used for the connection portions.

  Moreover, the nozzle part 3 installed in the other end of the double spray pipe part 2 is connected to the release agent passage 19 as shown mainly in FIGS. 2 and 4, and the oil release agent up to the nozzle port 26. Nozzle release agent passage 27 leading out 13 and nozzle release agent passage 27 are formed so as to surround the nozzle release agent passage 27, communicate with the air passage 24 of the double spray pipe portion 2, and lead out the compressed air 16 to the nozzle port 26. A passage 28 is provided. In addition, by making the shape of the nozzle port 26 as desired, the spray shape of the oil release agent 13 when spraying the oil release agent 13 using the pressurized air 16 to be described later is mist-like or droplet-like. It is possible to change freely.

  Further, as shown in FIGS. 1 and 2, the spray unit 1 of the present embodiment includes a male mold 8 a and a female mold that are spaced apart from each other (corresponding to the horizontal direction of the paper in FIG. 1) and are open. A pair of double spray pipe portions 2 are connected from the unit main body 18 to spray each mold inner surface 4 of 8b at the same time by one spray operation. Further, a pair of nozzle portions 3 in which the spray direction of the nozzle ports 26 is directed to the inner surface 4 of the mold to be sprayed are provided at the other ends (tips) of the respective double spray tube portions 2. Yes.

  Then, the timing of spraying the oil-based release agent 13 of the spray unit 1 by the release agent spraying device 6 and the nozzle opening 26 of the nozzle portion 3 are brought close to the mold inner surface 4 by the nozzle moving device 14. The movement control for moving to the spray position AP is performed by the control device 12 of the die casting machine 5 described above.

  Next, an example of a release agent spraying method using the spray unit 1 of the present embodiment will be described based on FIGS. 3 and 5. First, as described above, the die casting machine 5 used in the present embodiment is designed to obtain a mold release agent effect on the inner surface 4 of the mold using a water-soluble mold release agent which is currently mainstream. The release agent spraying device 6 and the release agent spray unit (not shown) installed therein are also for spraying a water-soluble release agent. Therefore, the existing release agent spray unit for the water-soluble release agent is removed from the unit body 18 in advance and replaced with the spray unit 1 for the oil-based release agent 13 of the present embodiment. Further, an oil-based release agent 13 to be sprayed is put into a release agent tank (not shown) of the release agent supply device 1 to operate the release agent supply device 15. Thereby, the oil-based mold release agent 13 supplied from the mold release agent supply device 1 is sent to the nozzle opening 26 through the unit main body 18, the double pipe spraying unit 2, and the nozzle unit 3 with a slight supply pressure. (Release agent weak supply process).

  Then, the control device 12 of the die casting machine 5 is operated so that the mold 8 is opened by the mold opening / closing device 10, and the mold inner surfaces 4 facing each other are exposed to the outside (mold opening process). Further, the nozzle moving device 14 is controlled to move the nozzle portion 3 of the spray unit 1 to the spray position AP (proximity process). Then, the pressurized air supply device 17 of the release agent spraying device 6 is operated. At this time, the value of the pumping pressure of the pumping air 16 is set to 0.3 MPa. Thereby, the pressurized air 16 is sent out from the pressurized air supply device 17 and flows through the air passage 24 of the air pipe 25 connected via the unit main body 18. At this time, in the double spray pipe part 2 in which the air passage 24 is formed, the release agent passage 19 for the oil-based release agent 13 and the air passage 24 for the pressurized air 16 are formed independently. Therefore, the oil release agent 13 and the pressurized air 16 are not mixed in the double spray pipe portion 2. Then, the pressurized air 16 that has flowed through the air passage 24 reaches the nozzle port 26 of the nozzle portion 3 and is ejected from the nozzle port 26 toward the inner surface 4 of the mold (a pressurized air ejection process). Note that the time from the operation of the pressurized air supply device 17 to the ejection of the pressurized air 16 from the nozzle port 26 is almost instantaneous.

  At this time, when the pressurized air 16 is ejected from the nozzle port 26, the pressure in the vicinity of the nozzle port 26 decreases in proportion to the flow rate of the pressurized air 16. This principle can be explained by “Bernoulli's theorem” known as one of the energy conservation laws concerning the motion of the fluid, which indicates that “the pressure decreases as the fluid velocity of the steady flow increases”. As a result, the oil release agent 13 supplied to the nozzle port 26 due to the negative pressure generated in the vicinity of the nozzle port 26 is sucked from the nozzle release agent passage 27 to the outside of the nozzle unit 3 through the nozzle port 26. The force to be applied acts. Thereby, the oil-based mold release agent 13 is pulled out of the nozzle part 3. In this state, the supply pressure is not applied from the release agent supply device 15 to the oil release agent 13 in particular. Then, the sucked oil release agent 13 is sprayed toward the inner surface 4 of the mold 8 together with the pressurized air 16 ejected from the nozzle port 26 (release agent application step).

  Thereafter, the oil-based mold release agent 13 that has reached the inner surface 4 of the mold spreads on the inner surface 4 of the mold due to its surface tension characteristics, and a uniform film F is formed. As shown in FIG. 5A, the spray unit 1 of the present embodiment is configured to have a pair of double spray pipe portions 2 and a nozzle portion 3 with respect to the unit main body 18. Therefore, the oil release agent 13 can be sprayed simultaneously on the inner surfaces 4 of the male mold 8a and the female mold 8b by one operation described above, and the time required for spraying is shortened. be able to. When spraying of the oil release agent 13 is completed, the nozzle moving device 14 retracts the double-tube spray unit 2 and the nozzle unit 3 to the separation position BP (see FIG. 5B), and the mold opening / closing device 10 molds the mold. Closed. Then, the casting of the die cast product is completed by performing the injection of the molten metal and the die cutting operation of the molded die cast product (not shown).

  As described above, according to the spray unit 1 of the present embodiment, it is independently formed on the outer periphery of the release agent passage 19 without directly supplying a strong pressure for spraying the oil release agent 13. The coating release F can be formed by spraying and adhering the oil release agent 13 to the inner surface 4 of the mold using the negative pressure suction force of the compressed air 16 flowing through the air passage 24. Therefore, as in the past, the pressurized air 16 and the oil-based release agent 13 (or water-soluble release agent) are mixed in the spray tube (see FIG. 6), and the pressure is directly applied to the gas-liquid mixture that is directly pressurized. It becomes possible to suppress the pressure of the air 16 being pumped, and accordingly, the possibility that the oil-based mold release agent 13 scatters around the die casting machine 5 and stains the installation floor surface or the like can be reduced. Moreover, in the spray unit 1 of this embodiment, the value of the pumping pressure of the pumping air 16 is set to 0.30 MPa. This can be set lower than 0.51 MPa to 0.7 MPa when an existing water-soluble release agent is used. Furthermore, the spray amount sprayed on the inner surface 4 of the mold can be reduced to about 0.5 cc to 4.0 cc from the conventional amount of 200 cc per second. As a result, a sufficient release agent effect is obtained, and the oil release agent 13 other than the mold inner surface 4 does not scatter, thereby reducing the cost for the subsequent waste liquid treatment and the like. In addition, since the spray amount sprayed onto the inner surface 4 of the mold can be reduced to the necessary minimum amount as described above, the variation in the mold temperature of the mold 8 preheated by spraying the oil release agent 13 is reduced. can do. Thereby, the load added to the metal mold | die 8 can be made small, generation | occurrence | production of a heat crack etc. can be suppressed and metal mold | die life can be extended.

  The present invention has been described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention as described below. And design changes are possible.

  That is, in the spray unit 1 of the present embodiment, the diameter of the release agent pipe 20 of the double spray pipe portion 2 is 2.5 mm, and the diameter of the air pipe 25 that accommodates the release agent pipe 20 is 6. Although what was set to 0 mm was shown, it is not limited to this, the release agent tube 20 is 1.5 mm or more and 3.5 mm or less, the air tube 25 is 5.0 mm or more and 7.0 mm or less, Further, it can be arbitrarily set as long as the oil-based release agent 13 can be sucked using the negative pressure generated by the flow of the compressed air 16. Moreover, the value of the pumping pressure of the pumping air 16 can be arbitrarily set as long as it is in the range of 0.2 MPa or more and 0.5 MPa or less. Note that the relationship between the diameters of the release agent tube 20 and the air tube 25 and the value of the pumping pressure of the pumping air 16 has a great influence on the suction effect due to the negative pressure. May be required.

  Further, in the spray unit 1 of the present embodiment, by changing the shape of the nozzle port 26, the oil-based mold release agent 13 can be diffused and sprayed over a wide area or sprayed in one place. A simple spot type nozzle can also be used. Moreover, it is not specifically limited to the shape of the nozzle part 3 as shown to FIG. 2 thru | or FIG. 4, It can comprise in a various shape. In addition, in the spray unit 1 of the present embodiment, the unit main body 18 is provided with a pair of double spray pipe portions 2, but the present invention is not limited to this. The number of the double spray pipe portions 2 to be installed and the nozzle portions 3 attached to the tips thereof can be appropriately set depending on the area and shape of the mold inner surface 4 to be sprayed.

It is explanatory drawing which shows schematic structure of the die-casting machine by which the spray unit of this embodiment is installed. It is an expanded sectional view showing typically composition of a double spray pipe part and a nozzle part of a spray unit. It is a partially notched perspective view which shows the structure of the double spray pipe part and nozzle part of a spray unit. It is a front view which shows the structure of a nozzle part. It is explanatory drawing which shows an example of use of a spray unit. It is explanatory drawing which shows the prior art example of the spray unit for die-casting.

Explanation of symbols

1,100 Spray unit (Die-casting spray unit)
2 Double spray pipe part 3,107 Nozzle part 4 Mold inner surface 5 Die casting machine 6 Mold release agent spray device 8 Mold 13 Oil release agent 15 Release agent supply device (release agent supply source)
16, 103 Pressurized air 17 Pressurized air supply device (Pressurized air supply source)
18, 105 Unit body 19 Release agent passage 20 Release agent pipe 21, 108 Inner space 22 Inner wall 23 Outer wall 24 Air passage 25 Air pipe 26, 109 Nozzle port 101 Water-soluble release agent 102 Release agent supply source 104 Air supply source

Claims (5)

The release agent passage through which oil-based release agent can flow and the air passage through which compressed air can flow are independent of each other, and through the release agent passage of the double spray pipe portion configured to have a double tube structure, An oil-based mold release agent weak supply step for supplying the oil-based material with a weak pumping pressure so as not to be ejected from the nozzle opening of the nozzle portion connected to the double spray pipe portion;
A proximity step of bringing the nozzle port close to the mold inner surface of the mold that has been opened;
Via the air passage of the double spraying tube section, and a pressurized air ejection step for ejecting the pressurized air from the nozzle port adjacent to the inner surface of the mold by the proximity step,
A release agent spraying method, wherein the oil release agent is sprayed on the inner surface of the mold by utilizing a suction force generated when the compressed air is ejected from the nozzle port. A die casting casting unit used in the mold release agent spraying method according to claim 1,
A unit main body installed in a release agent spraying device connected to a release agent supply means for supplying an oily release agent, and a pressurized air supply means for supplying pressurized air for spraying the oily release agent;
A release agent pipe having one end connected to the unit main body and formed with a release agent passage through which the oil release agent supplied from the release agent supply means can flow, and the release agent pipe in the pipe space And an air pipe in which an air passage through which the pressurized air supplied from the pressurized air supply means can flow is formed between the inner wall of the pipe and the outer wall of the release agent pipe, and the release agent A double spray pipe portion configured such that the passage and the air passage have an independent double pipe structure; and
A nozzle part installed at the other end of the double spray pipe part, and having a nozzle port communicating with the release agent passage and the air passage;
The oil release agent supplied to the nozzle port by the release agent supply means is sprayed on the inner surface of the mold by using a suction force generated when the compressed air is ejected from the nozzle port. A spray unit for die casting. The unit body is
Removably attached to the release agent spraying device,
The release agent spraying device comprises:
The spray unit for die casting according to claim 2, wherein the spray unit is attached to a die casting machine for spraying a water-soluble release agent on the inner surface of the mold. The pumping pressure of the pumping air supplied by the pumping air supply means is
The spray unit for die-casting according to claim 2 or 3, wherein the spray unit is set to 0.2 MPa or more and 0.5 MPa or less. The double spray pipe part is
A cylindrical tubular release agent tube having a tube diameter of 1.5 mm or more and 3.5 mm or less;
The die-cast casting according to any one of claims 2 to 4, wherein the die-casting is configured to include a circular tubular air pipe having a pipe diameter of 5.0 mm or more and 7.0 mm or less. Spray unit.

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