JP3560718B2 - Powder coating agent coating method and coating device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coating method and a coating apparatus for applying a powder coating agent to a mold.
[0002]
For example, in a low-pressure casting apparatus, casting water is generally supplied from a lower mold side into a cavity formed by a mold including an upper mold and a lower mold. 2. Description of the Related Art In order to improve the circulation of casting water to the inner surface of a mold or to improve the release of a casting, a powder coating agent is applied to the inner surface of a mold. In particular, it is strongly required to apply a powder coating agent to the surface of the upper mold in order to improve the circulation of the casting water on the surface of the upper mold (the mating surface to the lower mold) in which the temperature of the casting metal is lowered. Will be.
[0003]
The application of the powder coating agent to the inner surface of the mold is usually performed by spraying the powder coating agent onto the inner surface of the mold from a spray nozzle. In this case, the adhesion of the powder coating agent to the inner surface of the mold is poor, and it is strongly desired to increase the adhesion efficiency. That is, most of the powder coating agent sprayed from the spray nozzle toward the inner surface of the mold falls without adhering to the inner surface of the mold. Japanese Patent Application Laid-Open No. Sho 61-42462 proposes a device that utilizes electrostatic attraction to improve the adhesion efficiency.
[0004]
[Problems to be solved by the invention]
However, according to the above-mentioned publication, the powder coating agent that has been separated from the inner surface of the mold, that is, the powder coating agent that has fallen, cannot be adhered to the inner surface of the mold. Will be desired.
[0005]
Accordingly, an object of the present invention is to provide a method and an application for applying a powder coating agent which is capable of adhering the powder coating agent which has fallen without adhering to the inner surface of the mold to the inner surface of the mold again. It is to provide a device.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a method for applying a powder coating agent according to the present invention has the following configuration. That is,
A method of applying a powder coating agent to the inner surface of the upper mold of the mold,
In order to electrostatically adsorb the powder coating agent on the inner surface of the upper die, apply the powder coating agent so as to generate a voltage difference from the upper die by a voltage generator ,
While the inner surface of the upper mold is covered with a covering member so as to form a closed space, the spray nozzle is moved upwardly from the spray nozzle to the inner surface of the upper mold while moving the spray nozzle along the upper mold. While spraying, the powder coating agent that has fallen without adhering to the upper mold inner surface is scattered in the closed space by blow air that blows downward from the blow nozzle and adheres to the upper mold inner surface,
There is such a configuration.
[0007]
In order to achieve the above object, a powder coating agent applying apparatus according to the present invention has the following configuration. That is,
An apparatus for applying a powder coating agent to the inner surface of the upper mold of the mold,
The powder mold wash to be electrostatically attracted to the upper mold inner surface, a voltage generator you apply the powder coating agent to produce the upper mold and the voltage difference,
A covering member for covering the inner surface of the upper mold so as to be a closed space,
In the closed space, a spray nozzle for spraying the powder coating agent upward against the inner surface of the upper mold while moving along the upper mold,
In the closed space, a blow nozzle for blowing the blow air downward to scatter the powder coating agent that has fallen without adhering to the inner surface of the upper mold and attaching the powder coating agent to the inner surface of the upper mold,
Is provided.
[0008]
【The invention's effect】
According to the method of the present invention, the powder mold wash is dropped without adhering to the mold inner surface is blow - opportunities being scattered by the air adheres to the mold inner surface is increased, in conjunction with adsorption by electrostatic attraction This is preferable for improving the adhesion efficiency of the powder coating agent. In addition, since it is performed in an enclosed space, the dropped powder coating agent can be effectively scattered and adhered to the inner surface of the mold, and the situation where the powder coating agent leaks out to the surroundings can be prevented. This is also preferable in preventing environmental degradation.
In addition to the above, it is preferable in that the powder coating agent is effectively adhered to the uneven portion on the inner surface of the mold, and the adhesion efficiency is further improved.
Further, the adhesion efficiency when applying the powder coating agent to the surface of the upper mold, which is often performed , can be improved. Further, the powder coating agent falling by gravity can be effectively scattered by the blow air.
[0009]
According to the apparatus of the present invention, an apparatus for obtaining an effect corresponding to the method of the present invention can be provided.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 and 2 show a low-pressure casting machine to which the present invention is applied. In the embodiment, a cylinder head of an automobile engine is cast with an aluminum alloy. 1 and 2, reference numeral 1 denotes a lower platen, 2 denotes an upper platen which is driven up and down. A lower die 3 is fixed to the lower platen 1, and an upper die 4 is fixed to the upper platen 2.
[0011]
Reference numeral 5 denotes a core cart and reference numeral 6 denotes a product take-out cart (not shown in FIG. 2), each of which can run on a common rail 7. That is, when the upper mold 4 rises and the mold opening space K is formed between the carriage 5 and the lower mold 3, each carriage 5 can move into and out of the mold opening space K. Then, the core carrier 5 holds the core outside the mold opening space K, advances into the mold opening space K, processes the held core, and sets the core in the lower mold 3. Further, the core carrier 5 is equipped with an application box T described later for applying the powder coating agent to the inner surface of the mold of the upper mold 4 as described later. T is raised, and the powder coating agent is applied to the inner surface of the upper mold (the surface facing the lower mold 3 and facing downward) as described later.
[0012]
The upper mold 4 is lowered to match the lower mold 3, and then a casting is formed by supplying casting water into a cavity formed by the molds 3 and 4. Then, the formed cast product is taken out by the product take-out cart 6 to the end opposite to the core carrier 5 in a state where the upper mold 4 is raised to form the mold opening space K. The casting metal is supplied from the lower mold 3. In FIG. 2, the reference numeral 8 designates a holding furnace for the casting metal, and the reference numeral designates a stroke for supplying the casting metal from the holding furnace 8 to the lower mold. 9.
[0013]
The core carrier 5 will be described in more detail with reference to FIGS. First, the core carrier 5 has a core setting device 11 mounted thereon. The core setting device 11 has a base plate 13 which is moved up and down while being guided by a guide rod 12. The base plate 13 is a cylinder serving as a vertical drive means of the core setting device 11. The device 14 is driven up and down. A lower portion of the base plate 13 holds a plurality of holding claws 15 which are opened and closed in a direction perpendicular to the plane of FIG. 3 and an opening / closing mechanism including an actuator for opening and closing the holding claws 15. 16 are configured.
[0014]
The core setting device 11 has a positioning pin 17 a extending in the vertical direction in parallel with the holding claw 15, and the positioning pin 17 a is substantially constituted by a piston rod of the cylinder device 17. When the core carrier 5 comes to a predetermined position in the mold opening space K and the positioning pins 17a are lowered and inserted into the positioning holes of the lower mold 3, the positioning of the core carrier 5 in the mold opening space K is performed. Done. In this positioned state, the core setting to the lower mold 3 and the application of the powder coating agent to the inner surface of the upper mold are performed.
[0015]
The coating box T has an outer shell substantially constituted by a covering member 21. Inside the coating box T, as shown in FIGS. 5 to 7, a spray nozzle 22 for spraying a powder coating agent and a blower 22 are provided. -A blow nozzle 23 for blowing air is held. The cover member 21 is formed in a box shape having an opening only at an upper portion, and has a bottom wall portion and left, right, front and rear side wall portions. It faces the inner surface.
[0016]
The cover member 21 can be vertically driven at a position higher than the core setting device 11 (base plate 13), more specifically, at a position higher than the upper frame of the core truck 5, Is held in. That is, a plate 24 is provided on the outer wall of the cover member 21, and a cylinder device 25 as a vertical drive means is provided between the plate 24 and the core carrier 5. A guide rod 26 extending upward from the core carriage 5 slidably penetrates the plate 24 so that the cover member 21 can be smoothly moved up and down in accordance with expansion and contraction of the cylinder device 25. Has become.
[0017]
The covering member 21, the spray nozzle 22, the blow nozzle 23, and the like will be described in detail with reference to FIGS. First, a flange portion 21a is formed over the entire upper edge of the cover member 21, and a packing 31 made of an elastic member such as rubber is fixed over the entire length of the flange portion 21a. Thereby, when the cover member 21 is raised in the mold opening space K, as shown in FIG. 6, the packing 31 abuts on the lower surface of the upper mold 4, and the cover member 21 and the upper mold 4 cooperate. Thus, a closed space M is formed in the cover member 21.
[0018]
In the lower part of the front and rear side walls of the cover member 21, slits 32 are formed which extend in parallel to each other and extend over substantially the entire length of the cover member 21 in the left-right direction. An elongated rod-shaped holding member 33 is provided in the covering member 21, and each end of the holding member 33 penetrates the slit 32 slidably. A roller 34 as a running wheel is rotatably attached to one end 33a of the holding member 33 outside the covering member 21. The roller 34 runs on a guide rail 35 fixed to the outside of the side wall of the covering member 21. It is possible to run.
[0019]
A nut member 36 is fixed to the other end 33 b of the holding member 33 outside the cover member 21, and the nut member 36 is screwed to the outer periphery of a threaded rod 37 extending long along the slit 32. The screw rod 37 is rotatably held by the cover member 21. One end of the screw rod 37 is connected to a rotary actuator (motor in the embodiment) 38 as a driving means. Thus, for example, by rotating the actuator 38 forward, the nut member 36, that is, the holding member 33 is driven downward in FIG. 7, and by rotating the actuator 38 backward, the holding member 33 is driven upward in FIG. You.
[0020]
The spray nozzle 22 and the blow nozzle 23 are fixed to the holding member 33. The spray nozzle 22 has an elongated cylindrical main body 22a having both ends closed, and the cylindrical main body 22a has an internal elongated common space 22b and a plurality of communication holes 22c communicating with the common space 22b, respectively. . Each communication hole 22c is formed in series at intervals in the longitudinal direction of the cylindrical main body 22a, and a nozzle member 22d is attached to each communication hole 22c.
[0021]
The above-described spray nozzle 22 has a pair, and is fixed to the holding member 33 along the longitudinal direction of the holding member 33 and at an interval from each other. In FIG. 8, a screw hole for fixing to the holding member 33 is indicated by reference numeral 39. The attachment of the spray nozzle 22 to the holding member 33 is performed such that the nozzle member 22d faces upward.
[0022]
The blow nozzle 23 is also formed substantially in the same structure as the spray nozzle 22, but does not have a member corresponding to the nozzle member 22d, and the opening corresponding to the communication hole 22c is directly blown with the blow air. The outlet 23c (see FIG. 6). The blow nozzle 23 is fixed to the holding member 33 such that the blow air outlet 23c faces downward, that is, toward the bottom wall of the cover member 21. This blow nozzle 23 is also provided in a pair like the spray nozzle 22.
[0023]
The supply of the powder coating agent to the spray nozzle 22 is performed from a connecting member 41 attached to the bottom wall of the covering member 21 via a long flexible hose 41 disposed in the covering member 21. The hose 42 is connected to a common space 22b inside the spray nozzle 22 at a substantially middle portion in the longitudinal direction of the spray nozzle 22 (see FIGS. 8 and 9). The supply of blow air to the blow nozzle 23 is performed through an elongated flexible hose 43 passing through the slit 32.
[0024]
Two suction ports 44 are formed in the bottom wall of the covering member 21 at a substantially central portion thereof. The suction port 44 is connected to a suction device 46 (see FIG. 10) via a hose 45.
[0025]
FIG. 10 shows a connection system for the spray nozzle 22, the blow nozzle 23, and the suction port 44. In FIG. 10, the supplied original air passes through a regulator 51, a filter 52, and a dryer 53, and is converted into clean dry air adjusted to a predetermined pressure. After the dryer 53, the air is branched into five branch systems parallel to each other. The branch system 61 serves as a supply system for the powder coating agent, and reaches the spray nozzle 22 via an electromagnetic on-off valve 62, an ejector 63, and a high voltage application unit 64.
[0026]
The ejector 63 is connected to a powder coating agent storage tank 66 via a pneumatic on-off valve 65, and the powder coating agent is supplied from the tank 66 by air supplied from the system path 61 when the on-off valve 65 is open. The mold agent is sucked up and the powder coating agent is pumped to the spray nozzle 22. A branch system path 67 is connected to the pneumatic on-off valve 65, and an electromagnetic on-off valve 68 is connected to this system path 67. Thus, the pneumatic on-off valve 65 is opened and closed according to the opening and closing of the electromagnetic on-off valve 68. The high voltage application unit 64 applies a powder coating agent so that a predetermined high voltage difference is generated between the upper mold 4 and the high mold 4 by the high voltage generator 64A. The mold is attached.
[0027]
A branch line 69 is connected to the tank 66, and an electromagnetic on-off valve 70 is connected to the branch line 69. When the on-off valve 70 is opened, the powder coating agent in the tank 66 is stirred, and the transfer of the powder coating agent to the ejector 63 is assisted.
[0028]
A branch line 71 is connected to the tip of the ejector 63, and an electromagnetic on-off valve 72 is connected to the branch line 71. Thus, when the on-off valve 72 is opened, the purge air is supplied to the spray nozzle 22 via the ejector 23.
[0029]
The blow nozzle 23 is connected to a branch line 73, and an electromagnetic on-off valve 74 is connected to the branch line 73. By opening the on-off valve 74, blow air is blown from the blow nozzle.
[0030]
FIG. 11 shows the movement of the spray nozzle 22, the spraying of the powder coating agent from the spray nozzle 22, the blowing of blow air from the blow nozzle 23, the suction from the suction port 44, A time chart showing the relationship with the supply of the air is shown. In the example shown in FIG. 11, the spray nozzle 22 moves from the original position, which is one end of the cover member 21, to the forward end, and then returns to the original position again, and this one reciprocating movement This completes the application of the powder coating agent to the upper mold inner surface. The moving speed of the spray nozzle 22 is a constant speed.
[0031]
The application of the powder coating agent from the spray nozzle 22 is started from a position where the spray nozzle 22 is slightly advanced from the original position, and is temporarily stopped from a position slightly before the advanced end to a position slightly after the advanced end, and then the powder is sprayed again. The spraying of the body coating agent is resumed, and the spraying of the powder coating agent is terminated shortly before returning to the original position. The blowing mode of the blow air is performed in the same manner as the blowing of the powder coating agent.
[0032]
The start of suction from the suction port 44 is the same as the start of spraying of the powder coating agent. However, the end time of the suction is substantially later than the end of the spraying of the powder coating agent because the suction and collection of the powder coating agent remaining in the closed space M formed by the cover member 21 are performed. The timing is reached (the suction is executed for a while even after the spray nozzle 22 returns to the original position).
[0033]
The supply of purge air is started at a time slightly before the end of the spraying of the powder coating agent. The supply of purge air is continued for a while after the spray nozzle 22 returns to the original position, but the supply is stopped earlier than the end of suction.
[0034]
Here, the core set and the application of the powder coating agent will be described with reference to FIG. 12 and focusing on the movement of the core carrier 5. First, when the upper mold 4 is raised and the mold is opened, the core carrier 5 is moved toward the mold opening space K (S1). Then. In the mold opening space K, the core carrier 5 is positioned using the positioning pins 17a (S2). Thereafter, the setting of the core and the application of the powder coating agent are performed in parallel, the core setting is performed in steps S3 to S5 in FIG. 12, and the application of the powder coating agent is performed in steps S8 to S10. It is considered as processing.
[0035]
When setting the core in the lower die 3, first, the base plate 13, that is, the core is lowered by the cylinder device 14 (S3). Thereafter, the holding claws 15 are opened, and the core is set on the lower mold 3 (S4). Then, the base plate 13 is raised by the cylinder device 14.
[0036]
When applying the powder coating agent, first, the application box T, that is, the covering member 21 is raised by the cylinder device 25 (S8). Next, as described above, the powder coating agent is applied to the inner surface of the upper mold (S9), and the application box T is lowered by the cylinder device 25.
[0037]
When each of S5 and S10 ends, the positioning pin 17a is raised, and the positioning relationship between the core carrier 5 and the lower mold 3 is released (S6). Thereafter, the core carrier 5 is moved backward, that is, moved to the outside of the mold opening space K (S7).
[0038]
Although the embodiments have been described above, the present invention is not limited to this, and includes, for example, the following cases. That is, Ru can be applied to the case of casting an appropriate casting other than automotive engines.
[0039]
Coated fabric box T, that the covering member 21 may be configured separately by independent of the core carriage 5.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a casting apparatus to which the present invention is applied.
FIG. 2 is a side view of FIG. 2;
FIG. 3 is a diagram showing details of a core bogie;
FIG. 4 is a diagram showing details of a vertical drive portion of the application box.
FIG. 5 is a diagram of the cover member mounted on the core carrier when viewed from above.
FIG. 6 is a side sectional view showing a relationship among a mold, a cover member, a spray nozzle, and a blow nozzle.
FIG. 7 is a cross-sectional top view showing a spray nozzle, a blow nozzle, and a spray nozzle driving portion disposed in a cover member.
FIG. 8 is a view of the spray nozzle as viewed from above.
FIG. 9 is a side sectional view of FIG. 8;
FIG. 10 is a system diagram of a spray nozzle, a blow nozzle, and a suction port.
FIG. 11 is a time chart showing the relationship among the movement of a spray nozzle, blowing of a powder coating agent, blowing of blow air, suction and supply of purge air.
FIG. 12 is a flowchart showing a core set and a powder coating agent application in relation to the operation of the core cart.
[Explanation of symbols]
3: Lower die 4: Upper die 5: Core carrier 11: Core set device 14: Cylinder device (for lowering the core)
21: Cover member 22: Spray nozzle 23: Blow nozzle 25: Cylinder device (for raising the cover member)
38: Actuator (for spray nozzle movement)
44: suction port 46: suction device K: mold opening space T: coating box M: closed space

Claims (2)

A method of applying a powder coating agent to the inner surface of the upper mold of the mold,
In order to electrostatically adsorb the powder coating agent on the inner surface of the upper die, apply the powder coating agent so as to generate a voltage difference from the upper die by a voltage generator ,
While the inner surface of the upper mold is covered with a covering member so as to form a closed space, the spray nozzle is moved upwardly from the spray nozzle to the inner surface of the upper mold while moving the spray nozzle along the upper mold. While spraying, the powder coating agent that has fallen without adhering to the inner surface of the upper mold is scattered in the closed space by blow air that blows downward from a blow nozzle and adheres to the inner surface of the upper mold.
A method for applying a powder coating agent, characterized in that: An apparatus for applying a powder coating agent to the inner surface of the upper mold of the mold,
The powder mold wash to be electrostatically attracted to the upper mold inner surface, a voltage generator you apply the powder coating agent to produce the upper mold and the voltage difference,
A covering member for covering the inner surface of the upper mold so as to be a closed space,
In the enclosed space, a spray nozzle for spraying the powder coating agent upward against the inner surface of the upper mold while moving along the upper mold,
In the closed space, a blow nozzle for blowing out blow air downward to scatter the powder coating agent that has fallen without adhering to the inner surface of the upper mold and to adhere the powder coating agent to the inner surface of the upper mold,
An apparatus for applying a powder coating agent, comprising:

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