JP4245553B2 - Mold release agent applicator - Google Patents

Description

  The present invention relates to a mold release agent coating apparatus, and more particularly to a mold release agent coating apparatus for uniformly applying an oil-based mold release agent to a molding surface of an appropriate amount.

  Conventionally, as a mold for molding, for example, a mold for injection molding or die casting is composed of a pair of a first mold and a second mold, and molding surfaces of the first mold and the second mold Thus, a cavity forming portion is formed. For example, a molten resin is injected into the cavity forming part to mold a resin product. In this case, a release agent is applied to the molding surface of the mold in advance before injection molding in order to improve the punchability of the molded product molded in the cavity forming portion and prevent seizure of the mold. .

  As a conventional mold release agent coating apparatus, for example, the above-described release agent is ejected from a nozzle fixed at a predetermined position of the apparatus main body toward a molding surface of the mold. The mold is preheated to 300 ° C. in advance in order to improve the release property of the release agent.

  In addition, as the release agent, there are an aqueous release agent (water-soluble release agent) and an oil release agent. Oil-based mold release agents are superior to water-based mold release agents in terms of mold releasability and environmental conservation, but conventionally, water-based mold release agents are mostly used.

  As water-based mold release agents, the use of halogens has recently been restricted due to problems such as global environmental problems such as destruction of the ozone layer and adverse effects on the human body, and dichloromethane is similarly restricted. For this purpose, for example, an aqueous release agent of an emulsion in which a condensation reaction curable silicone polymer and a toluene solution of a curing agent are dispersed in water with a surfactant is used. Further, the water-based mold release agent has a difficulty in natural drying, and if it is sprayed too much, the portion tends to be insufficiently dried, which causes problems such as poor quality of the molded product and reduced productivity. In addition, when the water-based mold release agent is jetted onto the molding surface of the mold, the atmosphere (working environment) is poor because water vapor is generated or the waste adhering to the mold rises. .

In order to solve these problems, various ideas have been made so that the water-based mold release agent can be uniformly applied to the molding surface of the mold (see, for example, Patent Document 1).
JP 2002-66405 A

  By the way, in a conventional mold release agent coating apparatus, when using an oil release agent instead of a commonly used aqueous release agent, the oil release agent is simply used as a hydraulic pressure release agent. When sprayed in the form of a mist with air pressure, a lot of moisture is generated and the surroundings become sticky. For this reason, an operator needs to work, for example, wearing rubber work clothes or a hat, and there is a problem that work environment and work efficiency are poor. In addition, the conventional mold release agent coating apparatus has a problem that the application efficiency is low in the case of oil release agents as well as the aqueous release agents.

  Further, when using an oil-based mold release agent, the cost of the oil-type mold release agent is 100 times that of the water-based mold release agent. / Min., And a large amount is injected, so that there is a problem that the cost is significantly higher than that of the aqueous release agent. Further, when a large amount of the release agent is injected, there is a risk that environmental destruction will occur as a result.

  In view of the above, in conventional mold release agent coating apparatuses, it is desirable to use an oil release agent rather than an aqueous release agent if possible, but an aqueous release agent is mostly used for the reasons described above. is the current situation.

  In addition, the application state of the release agent to the mold varies depending on the skill level of the worker, and the quality of the molded product depends largely on the application state of the release agent. The type of the mold and its application state are important.

  The present invention has been made to solve the above-described problems.

In the mold release agent coating apparatus of the present invention, the molding surface sides of a pair of molds are arranged to face each other at a predetermined interval, and the molding surfaces of the respective molds are arranged within this interval. In a slit formed between a pair of upper nozzle blades and lower nozzle blades to apply a direct current high voltage of around −60 to 70 kV of negative pressure so as to charge and discharge the oil release agent A nozzle provided with a nozzle head having a shim made of a conductive material is disposed transversely to the vertical direction, and this nozzle is integrally provided with a voltage booster vertically on the upper nozzle blade via an adapter. The integrated nozzle, adapter, and voltage booster are provided so as to be reciprocable in the vertical direction of the mold and turnable at 180 ° in the vertical direction.
The shim includes an oil sump, a plurality of discharge flow path groups extending to the lower side of the sump, and an electrode for applying a voltage having a polarity opposite to the molding surface of each mold, and the oil sump. A release agent supply port for supplying the oil-based release agent to the lower nozzle blade of the nozzle,
A first release agent supply line communicating with the release agent supply port is provided, and an opening / closing valve including a three-way electromagnetic valve is provided in the middle of the first release agent supply line, and the opening / closing valve includes the first release agent supply line. A second release agent supply line that supplies a control device for controlling the supply amount of the oil release agent supplied to the release agent supply pipe and supplies the oil release agent from the release agent tank to the on-off valve. And a release agent discharge line for returning the oil release agent to the release agent tank,
The control device is connected to an upper portion of the voltage booster.

As can be understood from the means for solving the above problems, according to the present invention, since the release agent coating apparatus of the present invention is an electrostatic type, for example, the mold is grounded and has a positive potential. When a high direct current voltage of about −60 to 70 kV, which is a negative potential, is applied to the nozzle, the oil-based mold release agent instantly charges while passing through the nozzle, so that charges of the same polarity repel each other. Therefore, the oil release agent is discharged as fine particles having a uniform particle diameter, and then atomized and sprayed evenly toward the molding surface of the mold. As a result, in order for the atomized oil-based mold release agent to sufficiently penetrate into the details of the irregularities on the molding surface of the mold, the oil-based mold release agent can be uniformly applied to the molding surface. % Or more coating efficiency can be obtained.

  Therefore, even if the cost of the oil-based mold release agent is 100 times that of the water-based mold release agent, the application amount of the oil-based mold release agent is less than 1/100 that of the water-based mold release agent. Since it can be thinly applied to the molding surface of the mold, the oil-based mold release agent can be applied at the same cost as the water-based mold release agent or less. Therefore, by using an oil-based mold release agent, environmental conservation can be improved and the mold release property of the mold surface can be improved.

Further, while opposed to each other at a predetermined interval molding surface of a mold a pair, via the adapter arranged to be integrated with the voltage booster to the nozzle in this interval, the support A voltage booster integrated with the nozzle via an adapter so that the member can reciprocate in the longitudinal direction of the mold and the nozzle faces the molding surface of each mold. Since it is provided so as to be able to turn 180 ° in a direction substantially perpendicular to the direction, the oil-based mold release agent can be efficiently applied to the molding surfaces of a plurality of molds.

Furthermore, through the adapter together with the nozzles provided on both sides of the molding surface of each mold within this interval opposed to each other at a predetermined interval molding surface of a mold a pair Since the voltage booster is integrated and disposed so that the support member can reciprocate in the longitudinal direction of the mold, the oil release agent can be more efficiently applied to the molding surface of each of the plurality of molds. . In addition, since the on-off valve comprising a three-way solenoid valve is provided, the oil-based release agent can be supplied to the nozzle and returned from the nozzle to the release tank for circulation and reuse.

  Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1 and FIG. 2, in order to explain a mold release agent coating apparatus 1 according to this embodiment, in this embodiment, for example, a mold 3 for injection molding is used as an object to be coated. I will explain. The mold 3 for injection molding are made are arranged a pair of first mold 3A and a second mold 3B is a longitudinal-shaped structure, each forming surface of the first, second mold 3A, 3B 5, a cavity is formed. As shown in FIG. 1, the pair of first and second molds 3A and 3B has a predetermined interval on the molding surface 5 side of the first and second molds 3A and 3B. They are arranged opposite to each other.

Further, the mold release agent coating apparatus 1 according to this embodiment is an electrostatic type, and a discharge flow path group for discharging the oil release agent toward the molding surface 5 of each of the molds 3A and 3B. 9 and a nozzle 7 for applying a high voltage to charge the oil-based mold release agent are integrally attached to a lower portion of, for example, a voltage booster 11 as a support member via an adapter 13. The second molds 3A and 3B are disposed within the interval between the molding surfaces 5. The voltage booster 11 is for supplying a high voltage current to the nozzle 7.

  Further, as shown in FIG. 1, the support member reciprocates in the longitudinal direction of the first and second molds 3A and 3B with respect to the opposing surfaces of the first mold 3A and the second mold 3B. The nozzle 7 can be swung in a direction substantially perpendicular to the longitudinal direction so that the oil release agent can be sprayed toward the molding surfaces 5 of the first and second molds 3A and 3B. In addition, in this embodiment, it is provided so that it can be turned 180 °.

  In this embodiment, the first mold 3A and the second mold 3B are disposed on both the left and right sides of the nozzle 7 in FIG. The voltage booster 11 and the adapter 13 that support the nozzle 7 are movable in the vertical direction in FIG. 1 within the interval between the first mold 3A and the second mold 3B. Also, a clamp member 15 is clamped on the side of the upper portion of the voltage booster 11, and for example, the clamp member 15 is gripped by a robot (not shown), and the voltage booster 11, the adapter 13, and the nozzle 7 are integrated by this robot. Moved up and down or inverted by 180 °. The distance B between the tip of the nozzle 7 and the first and second molds 3A and 3B is about 200 to 250 mm.

  In this embodiment, the nozzle 7 is attached to the voltage booster 11 via the adapter 13. However, the nozzle 7 is not limited to the voltage booster 11 and may be attached to another support member. Further, the mechanism for reciprocating and reversing the nozzle 7 in the longitudinal direction of the mold 3 is not limited to the robot, and other moving means may be used.

  In addition, a first release agent supply pipe 17 is communicated with the nozzle 7 so as to supply the oil release agent to the discharge passage group 9. The first release agent supply pipe 17 is provided with, for example, a three-way electromagnetic valve 19 as an opening / closing valve for opening and closing the first release agent supply pipe 17. The second release agent supply pipe 21 communicates with the oil release agent, and the oil release agent is supplied from the release agent tank 27 by a gear-type liquid pump 25 that is rotationally driven by a liquid motor 23. It is supplied via the pipe line 21. Further, the oil release agent supplied through the second release agent supply pipe 21 when the first release agent supply pipe 17 is closed is again supplied to the three-way solenoid valve 19. A release agent discharge pipe 29 is communicated to return to the circulation.

  The upper portion of the voltage booster 11 is connected to a control device 31 connected to a power source, and the liquid motor 23 and the three-way electromagnetic valve 19 are connected to be controlled by the control device 31, respectively. .

  A second release agent supply pipe 21 between the liquid pump 25 and the three-way solenoid valve 19 is used to keep the fluid pressure of the second release agent supply pipe 21 and the liquid pump 25 constant. A relief valve 33 is interposed.

  Further, as shown in FIG. 2, the nozzle 7 is a nozzle head in which a single shim 41 is disposed as an electrode in a slit 39 formed between a pair of nozzle blades 35 and 37. 43 is provided. The nozzle blades 35 and 37 are made of an electrically insulating material such as insulating plastic, and the shim 41 is made of a conductive material made of a stainless steel sheet having a thickness of about 0.5 mm.

  The nozzle head 43 is provided with a connector pin 47 constituting, for example, a power connector 45 as an electrode for applying a negative high voltage to the shim 41 so as to protrude from the side surface of the nozzle blade 35.

  Further, between the surface of the shim 41 and the adjacent surface of the nozzle blade 37, an oil release agent discharge channel group 9 to be discharged toward the molding surface 5 of the mold 3 is formed. For example, the discharge flow path group 9 is etched at a groove depth C on one surface of the shim 41 (in this embodiment, the lower surface of the shim 41 in FIG. 2). Note that a release agent supply port 49 for supplying the oil release agent is communicated with the discharge flow path group 9.

  3 (A) and 3 (B), for example, as shim 41, oil reservoirs 51A and 51B and discharge flow path groups 9A and 9B are deep on the left surface in FIG. 3 (B). Etching is performed at C, and the discharge flow channel groups 9A and 9B extend from the oil sumps 51A and 51B, and a large number of flow channel grooves are arranged in parallel toward the downstream side. The intervals between the channels located at both ends on the most downstream side correspond to the application widths WA and WB of the oil release agent, and the application widths WA and WB can be set to about 50 mm, for example.

  The oil reservoirs 51A and 51B are communicated with a pair of release agent supply ports 49 in the nozzle blade 37 of the coating apparatus, and these release agent supply ports 49 are connected to the three-way solenoid valve 19 as shown in FIGS. To the liquid pump 25.

  The discharge flow path groups 9A and 9B act as capillary resistances, the resistance value is proportional to the length of the flow path, and the flow rate is inversely proportional to the square of the length. The application widths of the fluid discharged from the discharge flow path groups 9A and 9B are WA and WB, respectively. Accordingly, by opening and closing the three-way solenoid valve 19 on the upstream side of each discharge flow path group 9A, 9B, the coating width of the shim 41 as a whole can be set to WA, WB, WA + WB according to the molding surface 5 of the mold 3. It is possible to change.

  The relatively large circular openings 53 formed on both sides of the oil sumps 51A and 51B in the shim 41 are for passing fixing bolts to the support bracket and the like of the entire coating apparatus. A relatively small circular opening 55 disposed in the area adjacent to the sumps 51A and 51B is a stop for assembling the apparatus while maintaining liquid tightness between the shim 41 and the adjacent nozzle blades 35 and 37. A screw is passed through.

  In this embodiment, 16 channel grooves are arranged as discharge channel groups 9A and 9B in the coating widths WA and WB, respectively. Furthermore, the discharge outlet 57 of the final flow path of the discharge flow path groups 9A and 9B formed as described above has a rectangular shape.

  In the above-described embodiment, a single shim 41 as shown in FIGS. 3A and 3B is mounted between a pair of nozzle blades 35 and 37. Alternatively, a large number of shims 41 can be arranged in parallel to increase the overall length of the coating width.

  In the above-described embodiment, the three-way electromagnetic valve 19 is used as an opening / closing valve for opening / closing the first release agent supply pipe 17. However, an electromagnetic valve of another form may be used. . Further, when a plurality of discharge flow path groups 9 are provided in the nozzle 7, a plurality of first release agent supply conduits 17 communicate with each of the plurality of discharge flow path groups 9, and A plurality of on-off valves for opening and closing the one release agent supply pipe line 17 are provided corresponding to each first release agent supply pipe line 17, and the plurality of on-off valves are connected to the second release agent supply pipe line 17. It can be connected to a manifold communicated with the front end of the passage 21. As a result, the oil release agent is controlled and supplied to each discharge flow path group 9 by each corresponding electromagnetic valve. Thereby, the application width can be adjusted.

  Next, the operation of the above configuration will be described.

  Referring to FIGS. 1 and 2, the oil-based release agent is supplied from a release agent tank 27 through a second release agent supply pipe 21 by a liquid pump 25 that is rotationally driven by a liquid motor 23, and a three-way solenoid valve 19. Supplied to. When the oil release agent is sprayed from the nozzle 7 toward the molding surface 5 of the mold 3, the operation of the three-way electromagnetic valve 19 opens the first release agent supply pipe 17 side. Since the release agent discharge conduit 29 side is closed, the oil release agent in the second release agent supply conduit 21 is discharged through the first release agent supply conduit 17 from the nozzle 7. It sprays toward the molding surface 5 of the metal mold | die 3 from each discharge port 57 of the final flow path of the flow path groups 9A and 9B.

  On the other hand, when the oil release agent is not sprayed from the nozzle 7, the operation of the three-way solenoid valve 19 closes the first release agent supply pipe 17 side and the release agent discharge pipe 29 side. Since it is opened, the oil-based release agent in the second release agent supply pipe 21 is discharged and circulated back to the release agent tank 27 via the release agent discharge pipe 29.

  Furthermore, referring to FIG. 2, the operation when the oil release agent is sprayed from the nozzle 7 will be described in detail. The mold 3 is grounded and has a positive potential. Therefore, when a negative DC high voltage (around −60 to −70 kV) is applied to the shim 41 via the power connector 45, the control device 31 activates the three-way solenoid valve 19, and the oil release agent is removed. Controlled by the control device 31 and supplied to the release agent supply port 49 via the first release agent supply pipe 17, the oil release agent supplied from the release agent supply port 49 is discharged from the shim 41. Since they are charged instantly while passing through the path groups 9A and 9B, charges of the same polarity repel each other. As a result, the oil-based release agent is atomized as fine particles having a uniform particle diameter and sprayed evenly from the tip of the nozzle head 43 toward the molding surface 5 of the mold 3. The diffusion width A of the oil release agent on the molding surface 5 of the mold 3 is spread evenly according to the injection amount of the oil release agent.

  Therefore, even if the minimum amount of oil-based mold release agent is sprayed toward the molding surface 5 of the mold 3, since it is the electrostatic mold release agent coating apparatus 1, even if the molding surface 5 of the mold 3 is used. The oil-based mold release agent is evenly applied evenly to the molding surface 5 so that the oil-based mold release agent sufficiently penetrates into the details of the uneven surface of the mold 3 due to the electrostatic effect. And a coating efficiency of 90% or more can be obtained.

  The nozzle 7 is moved up and down integrally between the pair of first mold 3A and second mold 3B together with the voltage booster 11 gripped by the clamping member 15 by a robot (not shown). For example, the nozzle 7 descends while the oil-based mold release agent is sprayed from the tip of the nozzle head 43 toward the molding surface 5 of the first mold 3A on the left side in FIG. 1, thereby forming the first mold 3A. The oil release agent is evenly applied to the surface 5.

  Next, the nozzle 7 is inverted 180 ° around the inversion center integrally with the voltage booster 11 by the robot as shown by a two-dot chain line in FIG. Next, the oil-based mold release agent rises while being sprayed from the tip of the nozzle head 43 toward the molding surface 5 of the second mold 3B on the right side in FIG. 1, whereby oil is applied to the molding surface 5 of the second mold 3B. System release agent is applied evenly. As described above, when the nozzle 7 reciprocates once in the vertical direction, the oil-based mold release agent is efficiently applied to the molding surfaces 5 of the pair of first and second molds 3A and 3B facing each other. Is done.

  From the above, since the mold release agent coating apparatus 1 according to the embodiment of the present invention is an electrostatic type, even if the cost of the oil release agent is 100 times that of the aqueous release agent. The application amount of the oil-based mold release agent is a necessary minimum amount which is less than 1/100 of that of the water-based mold release agent due to the electrostatic effect, and can be uniformly and uniformly applied to the molding surface 5 of the mold 3. Therefore, the oil-based release agent can be applied at the same cost as the water-based release agent or less. In addition, by using an oil-based mold release agent, environmental conservation can be improved as compared with the water-based mold release agent, and the mold release property of the molding surface 5 of the mold 3 can be improved.

  In addition, this invention is not limited to embodiment mentioned above, It can implement in another aspect by making an appropriate change.

  In the above-described embodiment, an example in which an oil-based mold release agent is applied to the molding surfaces 5 of the pair of first and second molds 3A and 3B that constitute the injection mold 3 on both sides of the nozzle 7. However, the present invention can also be applied to a case where a plurality of pairs of molds 3 are arranged opposite to each other on both sides of the nozzle 7 with the nozzle 7 interposed therebetween. For example, FIG. 4 is a plan view, and two pairs of molds 3 are arranged opposite to each other at a predetermined interval with the nozzle 7 interposed therebetween. In this case, the molding surfaces 5 of the two pairs of molds 3 are arranged so that the sides thereof face each other.

  Further, the reversal (turning) angle of the nozzle 7 is not limited to 180 ° in the above-described embodiment, and can be reversed to any angle. Further, the nozzle 7 can be reversed to a desired position without hitting the mold 3 by reversing at a position away from the mold 3 in the reciprocating direction. In the example of FIG. 4, after applying the oil-based mold release agent to the molding surface 5 of one mold 3 while the nozzle 7 moves upward, the molding surface of the adjacent mold 3 is reversed after 90 ° reversal. The oil-based release agent is applied while moving downward relative to 5. Further, the oil-based mold release agent can be applied to the adjacent mold 3 after the nozzle 7 repeats the same operation and reverses 90 °. Therefore, as another example, when three pairs of molds 3 are arranged, the inversion angle to the adjacent mold 3 is approximately 60 °. In the above embodiment, the gear type liquid pump 25 is used as an example. However, a pressurization type pump device can be used.

  In the above embodiment, an example in which one nozzle 7 is provided below the support member 11 has been described. However, in FIG. 1, when the gap between the mold 3A and the mold 3B is narrow. Without rotating the nozzle 7, the nozzles 7 are provided on both sides of the lower part of the support member, and are moved back and forth, that is, moved up and down, to simultaneously apply the mold release agent to the molding surfaces of the molds 3A and 3B. By doing so, the further coating efficiency can be improved.

1 is an overall system configuration diagram illustrating a mold release agent coating apparatus according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a mold release agent coating apparatus according to an embodiment of the present invention. (A) is the front view in which the discharge flow path group was formed in one surface of the shim of embodiment of this invention, (B) is the state which expanded the cross section along the oil sump and the discharge flow path group FIG. It is a partial top view which shows the mold release agent application | coating apparatus of the metal mold | die of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold release agent coating apparatus 3 Mold 3A 1st mold 3B 2nd mold 5 Molding surface 7 Nozzle 9, 9A, 9B Discharge flow path group 11 Voltage booster 13 Adapter 15 Flange part 17 1st mold release agent supply pipe Road (release agent supply path)
19 Three-way solenoid valve (open / close valve)
21 Second release agent supply line 23 Liquid motor 25 Liquid pump 27 Release agent tank 29 Release agent discharge line 31 Control device 33 Relief valves 35 and 37 Nozzle blade 39 Slit 41 Shim 43 Nozzle head 45 Power connector (electrode) )
47 Connector pin (electrode)
49 Release agent supply ports 51A, 51B Oil sump 57 Discharge port

Claims (1)

The molding surface sides of the pair of molds are arranged opposite to each other with a predetermined interval, and the oil-based release agent is charged and discharged toward the molding surface of each mold within this interval. A nozzle head in which a shim made of a conductive material is disposed in a slit formed between a pair of upper nozzle blades and lower nozzle blades so as to apply a DC high voltage of about −60 to 70 kV of negative pressure as much as possible. The nozzle provided is arranged transversely to the vertical direction, and this nozzle is integrally provided with a voltage booster in the vertical direction via an adapter on the upper nozzle blade, and this integrated nozzle, adapter, voltage booster Is provided so as to be capable of reciprocating in the vertical direction of the mold and capable of turning 180 ° in the vertical direction,
The shim includes an oil sump, a plurality of discharge flow path groups extending to the lower side of the sump, and an electrode for applying a voltage having a polarity opposite to the molding surface of each mold, and the oil sump. A release agent supply port for supplying the oil-based release agent to the lower nozzle blade of the nozzle,
A first release agent supply line communicating with the release agent supply port is provided, and an opening / closing valve including a three-way electromagnetic valve is provided in the middle of the first release agent supply line, and the opening / closing valve includes the first release agent supply line. A second release agent supply line that supplies a control device for controlling the supply amount of the oil release agent supplied to the release agent supply pipe and supplies the oil release agent from the release agent tank to the on-off valve. And a release agent discharge line for returning the oil release agent to the release agent tank,
A mold release agent coating apparatus, wherein the control device is connected to an upper portion of the voltage booster.

Images