JP4194966B2 - Mold apparatus for casting and application method of release agent - Google Patents

Description

  The present invention relates to a casting mold apparatus having a mechanism for applying a release agent to a core pin and a method for applying the release agent to the core pin.

  2. Description of the Related Art Some casting mold apparatuses are provided with mold components called “casting pins” so as to be capable of appearing and retracting in molding cavities in the mold body. When a mold release agent is applied to the cavity inner surface of such a mold apparatus, the cast pin is arranged at the protruding position, and the spray gun is inserted into the mold body in the mold open state, and the spray gun In general, a mold release agent is sprayed from. However, in that case, the mold release agent adheres to the half peripheral surface facing the spray gun out of the entire outer peripheral surface of the core pin, but from the spray gun almost all the mold release agent adheres to the other half peripheral surface that is the dead angle. do not do. For this reason, after mold closing and pouring, when the die pin is pulled back to the immersive position and the die is opened, the resulting cast product has a problem that a lack of thickness occurs in the die cast portion by the die pin.

  In order to solve such problems, Patent Documents 1 and 2 disclose a release agent coating apparatus that can uniformly apply a release agent to the entire peripheral surface of a core pin. In the coating apparatus, a release agent application chamber that can surround a core pin that has receded from the cavity is provided, and a plurality of injection nozzles that can selectively inject compressed air and a release agent to the peripheral wall of the application chamber. The nozzle holes are formed at intervals in the circumferential direction. The mold release agent can be uniformly applied to the entire circumference of the cast pin by spraying the mold release agent all at once from the nozzles surrounding the cast pin retracted to the mold release agent application chamber.

  By the way, a mold release agent that is widely used today is mainly an emulsion type composed of water and a release component (for example, silicone oil) and one of them is dispersed in the other. It is designed assuming that the target mold component (including the cast pin) is heated and is in a predetermined temperature range (for example, 150 to 250 ° C.). That is, when a mold release agent is sprayed on a mold component in a heated state, the moisture evaporates and only the mold release component remains on the mold surface. The component is designed to form a release layer by forming a film or the like, thereby exhibiting release properties.

  In this respect, in the coating apparatus disclosed in Patent Documents 1 and 2, since the release agent is directly sprayed and applied from the nozzle on the peripheral wall of the coating chamber to the surface of the core pin, the mold release is applied to the surface of the core pin. The agent tends to adhere excessively. Therefore, the cast pin having a small heat capacity compared to the mold body may be overcooled by an excessive mold release agent. In particular, when the release agent is an emulsion type as described above, there is a high possibility that the release agent that should have been uniformly applied will also flow down from the pin surface before moisture evaporation and the like are completed. After all, in spite of elaborating the devices as described above, the adhesion of the mold release component to the outer peripheral surface of the core pin becomes non-uniform or insufficient, and the mold releasability (and eventually) Prevention of lack of meat) is not improved so much.

Japanese Utility Model Publication No. 62-159949 (see full text) Japanese Utility Model Publication No. 62-159950 (see the full text)

  The object of the present invention is to prevent the release agent from excessively adhering to the outer peripheral surface of the core pin to be coated, and to uniformly apply the release agent to the entire peripheral surface of the core pin. An object of the present invention is to provide a casting mold apparatus and a method for applying a release agent. In particular, an object of the present invention is to provide a casting mold apparatus and a method for applying a release agent that are suitable for the use of an emulsion release agent.

The invention of claim 1 includes a mold body that divides the cavity, a pin holder portion that holds the core pin so that it can protrude into and out of the cavity, and a release agent coating mechanism provided in the pin holder portion. In the casting mold apparatus, the release agent application mechanism includes an introduction path for introducing the release agent and gas from the outside into the pin holder portion, and a porous disposed near the exit of the introduction path And the porous body has a ring shape so as to surround the outer peripheral surface of the core pin and to face the outer peripheral surface of the core pin to be coated in a non-contact state. A casting mold apparatus is provided.

According to claim 1, the release agent and the gas introduced into the pin holder portion from the outside are guided to the porous body disposed near the outlet via the introduction path, and pass through the porous body. Then, it is supplied to the outer peripheral surface of the core pin to be coated. At that time, the porous body functions as an atomizing means for further atomizing or atomizing the release agent by stirring and mixing the passing release agent and gas based on the porous structure, and the flow resistance of gas and the like. (Or discharge resistance) and serves to suppressively adjust the injection amount of the release agent. Therefore, in the space between the porous body and the outer peripheral surface of the casting pin, a quantitatively controlled release agent is sprayed from the porous body, and the minimum amount of mist-like release agent is cast. It will be attached and applied to the outer peripheral surface of the pin. Therefore, it is possible to prevent the mold release agent from excessively adhering to the outer peripheral surface of the core pin, and to avoid the situation where the mold release agent once adhered flows down from the surface of the core pin. In addition, since the porous body facing the outer peripheral surface of the core pin has a ring shape and surrounds the outer peripheral surface of the core pin, the entire surface of the core pin is sprayed by the release agent sprayed from the porous body. A release agent is uniformly applied.

The invention of claim 2 includes a mold body that divides the cavity, a pin holder part that holds the core pin so that it can protrude into and out of the cavity, and a release agent coating mechanism provided in the pin holder part. In a casting mold apparatus,
The release agent application mechanism includes an introduction path for introducing a release agent and gas from the outside into the pin holder portion, and a porous body disposed near an outlet of the introduction path,
The cast pin has a relatively large diameter proximal end and a relatively small diameter distal end,
Wherein the pin holder portion, the straight cylindrical pin receiving chamber having an inner diameter corresponding to the diameter of the proximal end portion of the core pin is formed, the core pin is held in the pin receiving chamber,
The porous body has a ring shape, and an inner peripheral surface thereof is provided so as to constitute an inner peripheral wall of the straight cylindrical pin accommodating chamber, and is applied to an outer peripheral surface of the core pin to be coated. It is provided so that it may face in a non-contact state .

According to the second aspect , the relatively large diameter base end portion of the core pin is fitted into the straight cylindrical pin accommodating chamber formed in the pin holder portion, so that the core pin is inserted into the cavity. It is held so that it can appear and disappear. When the core pin protrudes from the pin housing chamber, the relatively small diameter tip of the core pin protrudes into the cavity and serves as a mold component, while the core pin is relatively large. Since the base end portion having a large diameter occupies the pin housing chamber, the porous body and the introduction path provided in the pin holder portion are blocked from the cavity. Therefore, the molten metal does not enter the pin accommodating chamber or the porous body when pouring into the cavity.

  When the core pin is immersed in the pin housing chamber, the relatively small diameter tip portion of the core pin is disposed in the pin housing chamber, and the small diameter tip portion and the inner peripheral wall of the pin housing chamber are provided. A predetermined clearance is secured between the ring-shaped porous body. That is, the outer peripheral surface of the small diameter tip portion of the core pin to be coated is surrounded by the ring-shaped porous body in a non-contact state. Therefore, the release agent is uniformly applied to the entire peripheral surface of the small diameter tip of the core pin by spraying the release agent from the porous body.

The invention of claim 3 is a method of applying a mold release agent to the casting pin constituting the casting die device, and is formed in a ring shape so as to surround the outer peripheral surface of the casting pin to be applied . The porous body is disposed in a non-contact state, a release agent and a gas are supplied to the porous body, and the release agent that has passed through the porous body is applied to the surface of the core pin. This is a method of applying a mold.

According to claim 3 , the release agent supplied to the porous body arranged in a non-contact state so as to surround the outer peripheral surface of the core pin passes through the porous body and is applied to the surface of the core pin. Is done. At that time, based on the porous structure of the porous body, the release agent and gas passing therethrough are agitated and mixed to further atomize or atomize the release agent, and the porous body itself circulates gas and the like. It becomes resistance (or discharge resistance), and the injection amount of the release agent is adjusted in a suppressive manner. Therefore, the minimum amount of mist-like mold release agent is adhered and applied to the surface of the core pin. Therefore, it is possible to prevent the mold release agent from excessively adhering to the surface of the core pin, and to avoid a situation where the mold release agent once adhered flows down from the surface of the core pin. In addition, since the porous body has a ring shape and surrounds the outer peripheral surface of the core pin, the release agent is uniformly applied to the entire peripheral surface of the core pin by spraying the release agent from the porous body. The

According to a fourth aspect of the present invention, in the method for applying a release agent according to the third aspect , the release agent is a dispersion emulsion type release agent comprising water and a release component.

According to the fourth aspect , when the dispersion emulsion type release agent composed of water and the release component becomes mist and adheres to the surface of the core pin, the heat held by the core pin (this heat is, for example, the previous time). Moisture evaporates and mold release components remain on the surface of the pin due to residual heat when it is transferred from the molten metal to the core pin during pouring. The release component remaining on the pin surface is then developed on the pin surface, and a release layer is formed by, for example, film formation. The mold release agent that has passed through the porous body is highly atomized and the amount thereof is also suppressed to the required minimum amount, so even if it adheres to the core pin with a small heat capacity compared to the mold body, The core pin is not cooled excessively. Therefore, moisture evaporation and the like proceed rapidly due to the heat held by the core pin, and the release layer is reliably formed on the surface of the pin by the release component without the release agent flowing down from the surface of the core pin.

  According to the casting mold apparatus of the present invention, it is possible to prevent the release agent from excessively adhering to the outer peripheral surface of the core pin to be coated, and to apply the release agent to the entire peripheral surface of the core pin. It becomes possible to apply uniformly.

  According to the method for applying a mold release agent of the present invention, it is possible to prevent the mold release agent from excessively adhering to the outer peripheral surface of the core pin to be applied, and to release the mold release agent on the entire peripheral surface of the core pin. Can be applied uniformly. For this reason, the coating method of the present invention is particularly suitable as a coating method for an emulsion mold release agent.

  An embodiment in which the present invention is embodied in a mold apparatus used for casting an aluminum die-cast product for an automobile will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the casting mold apparatus includes at least a mold body (11, 12) and a pin holder portion 20 that holds the core pin 40 so as to be retractable. The mold body includes a fixed mold 11 and a movable mold 12 provided so as to be close to and away from the fixed mold 11. By changing the mold open state (see FIG. 1) where both molds are separated from each other to the mold closed state (see FIG. 2) in which the movable mold 12 is joined to the fixed mold 11, a mold space or A cavity C as a casting space is defined.

  As shown in FIG. 1, a pin holder portion 20, which is an element constituting a mold together with the fixed mold 11 and the movable mold 12, is provided on a part of the fixed mold 11. The pin holder portion 20 includes a holder main body portion 21 and a lower lid portion 24 located at the lower end thereof. The holder main body 21 includes a pin insertion hole 22 having a circular cross section extending in the vertical direction at the center position, and a ring-shaped cylinder having a cross section at a position around the pin insertion hole 22 with a predetermined thickness. A shaped passage 23 is provided. On the other hand, the lower lid portion 24 of the pin holder portion is provided with a central hole 25 that is continuous with the pin insertion hole 22 at a central position thereof, and a concave portion 26 that has a circular cross section centered on the central hole 25. Yes. The outer diameter of the recess 26 substantially matches the outer diameter of the cylindrical passage 23.

  A ring-shaped porous body 30 is fitted into the concave portion 26 of the lower lid portion 24. The porous body 30 is formed by ring-shaped porous stainless steel having a pore diameter of 0.05 to 0.20 mm and a porosity of 10 to 40%. The ring-shaped porous body 30 has a center hole 31 having the same inner diameter as the pin insertion hole 22 and the center hole 25 and has a height corresponding to the depth of the recess 26. Accordingly, the lower lid portion 24 in a state where the ring-shaped porous body 30 is fitted in the concave portion 26 is fixed to the lower end of the holder main body portion 21 so that the pin holder portion 20 has a pin insertion hole 22 in the holder main body portion. The center hole 25 of the lower lid part and the center hole 31 of the ring-shaped porous body constitute a straight cylindrical pin accommodating chamber extending continuously in the vertical direction. The inner peripheral surface of the central hole 31 of the ring-shaped porous body 30 constitutes a part of the inner peripheral wall of the pin accommodating chamber (22, 25, 31).

  In the pin accommodating chamber (22, 25, 31), the core pin 40 is held so as to be vertically movable. The core pin 40 has a relatively large-diameter base end portion (upper end portion) 41 and a relatively small-diameter front end portion (lower end portion) 42. The outer diameter of the pin substantially coincides with the inner diameter of the pin accommodating chamber (22, 25, 31). As shown in FIG. 1, when the core pin 40 is disposed at the immersive position where the tip portion 42 of the core pin is completely accommodated in the pin housing chamber, the inner peripheral wall of the pin housing chamber and the core pin tip portion 42. A clearance (gap) having an annular cross section is formed between the outer peripheral surface and the outer peripheral surface. The radial width of this clearance corresponds to the radial difference between the base end portion 41 and the tip end portion 42 of the core pin. Further, when the core pin 40 is disposed at the immersion position, the ring-shaped porous body 30 surrounds the outer peripheral surface of the core pin tip portion 42 and faces the outer peripheral surface in a non-contact state.

  On the other hand, as shown in FIG. 2, when the core pin 40 is disposed at a projecting position where the tip portion 42 of the core pin completely protrudes from the pin housing chamber, the base end portion 41 and the tip portion 42 of the core pin are disposed. The step surface located at the boundary with the lower end surface of the lower lid 24 is flush with the lower end surface of the lower lid portion 24, and the entire pin housing chamber (22, 25, 31) is closed by the base end portion 41 of the core pin. The core pin 40 is operatively connected to a vertical driving mechanism 43 of the pin, and is switched between the immersion position and the protruding position by the action of the vertical driving mechanism 43.

  Further, a conduit 27 communicating with the cylindrical passage 23 in the holder main body 21 is provided at the upper portion of the pin holder portion 20. The conduit 27 is connected to a release agent supply source (for example, a pressure pump) 28 and a compressed air supply source (for example, an air compressor) 29, and the release agent and the compressed air are supplied from the supply sources 28 and 29 to the above-described supply source. It is introduced into the cylindrical passage 23. That is, the conduit 27 and the cylindrical passage 23 form an introduction path for introducing the release agent and gas into the pin holder portion 20 from the outside. In the present embodiment, the release agent is applied to the pin holder portion 20 by the introduction path (23, 27) including the conduit and the cylindrical passage, and the ring-shaped porous body 30 disposed near the exit of the introduction path. A mechanism is built.

  Next, a method of applying a release agent to the outer peripheral surface of the tip end portion of the core pin 40 using the above casting die apparatus will be described. In this embodiment, an aqueous dispersion emulsion type release agent prepared by dispersing silicone oil as a release component in water is prepared in the release agent supply source 28.

  At the time of the previous casting, as shown in FIG. 2, the mold main body (11, 12) is in the mold closed state, the casting pin 40 is arranged at the protruding position, and the pin tip 42 enters the cavity C. It becomes. By casting a molten metal such as molten aluminum into the cavity C through a not-shown pouring mechanism, a cast product corresponding to the internal shape of the cavity C (and the external shape of the die pin tip 42) is manufactured. . At that time, as a matter of course, the heat of the molten metal is also transmitted to the mold body and the core pin 40. Therefore, the fixed mold 11, the movable mold 12, the pin holder portion 20 and the core pin 40 continue to have heat even after the backward movement of the core pin 40 and the mold opening are completed, and the predetermined time is determined according to the respective heat radiation characteristics. , Hold a predetermined temperature. Speaking of the core pin 40, a temperature of about 150 to 250 ° C. is maintained for a certain time immediately after the mold opening.

  When the mold body (11, 12) is opened, as shown in FIG. 1, the core pin 40 is disposed at the immersion position, and the pin tip 42 is completely accommodated in the pin accommodating chamber (22, 25, 31). The At this time, the ring-shaped porous body 30 surrounds the outer peripheral surface of the core pin tip 41 and faces the outer peripheral surface in a non-contact state.

  When the release agent is applied to the core pin 40, the outlet side valve of the release agent supply source 28, the outlet side valve of the compressed air supply source 29, and the mixing valve located downstream of these two valves are opened. It is. Then, the release agent and the compressed air are introduced into the conduit 27 and mixed in the conduit 27 and the cylindrical passage 23. Further, the mixed release agent and compressed air are guided into the porous body 30 in search of the outlet, and after passing through the porous body 30, a clearance region secured around the core pin tip portion 42. To be released. At that time, based on the porous structure of the porous body 30, re-diffusion of the release agent by compressed air is promoted, and the release agent is sprayed on the clearance region as extremely fine particles. At that time, the porous body 30 itself becomes a flow resistance (or discharge resistance) of compressed air or the like, and the spray amount of the release agent is adjusted in a suppressive manner. For this reason, a release agent that is quantitatively suppressed is sprayed in the clearance region between the porous body 30 and the core pin tip portion 42. Further, when the mixing valve or the like is opened, the core pin 40 is slowly lowered from the immersion position (see FIG. 1) toward the protruding position (see FIG. 2). Therefore, the minimum amount of mist-like mold release agent is adhered and applied to the entire outer peripheral surface (from bottom to top) of the core pin tip portion 42.

  When the water-dispersed emulsion-type release agent composed of water and a release component (silicone oil) forms a mist and adheres to the outer peripheral surface of the core pin tip 42, moisture is evaporated by the heat of the core pin 40. Only the release component remains on the pin surface. The release component develops on the outer peripheral surface of the pin, and forms a release layer by, for example, film formation. The mold release agent sprayed from the porous body 30 is highly atomized and the amount thereof is suppressed to the necessary minimum amount, so that the heat capacity is smaller than that of the mold body (11, 12). Even if it adheres to the pin 40, the core pin 40 is not excessively cooled, and moisture evaporation and mold release layer formation by the heat of the core pin 40 proceeds rapidly. Therefore, the release agent adhering to the outer peripheral surface of the core pin tip portion 42 does not flow down from the pin surface, and a release layer due to the release component is quickly and reliably formed on the pin surface.

  As described above, according to the present embodiment, the release agent and the compressed air are supplied to the porous body 30, and only the minimum amount of the release agent sprayed through the porous body 30 is applied. It is applied to the outer peripheral surface of the extraction pin tip 42. Therefore, it is possible to prevent the mold release agent from excessively adhering to the outer peripheral surface of the core pin tip portion 42 and to avoid a situation in which the mold release agent once adhered flows down from the surface of the core pin 40.

  In addition, since the outer peripheral surface of the core pin 40 is surrounded by the ring-shaped porous body 30, the mold release agent is released on the entire peripheral surface of the core pin tip 42 by spraying the release agent from the porous body 30. The agent can be applied uniformly. As a result, seizure of the core pin 40 is prevented and the life of the pin is extended, and a lack of thickness at the trace portion of the core pin 40 can be prevented. In addition, since the dimensional accuracy of the trace portion of the core pin 40 is improved, post-processing such as cutting required after casting becomes unnecessary, or the processing cost for post-processing is reduced as compared with the prior art. It becomes possible.

  According to this embodiment, when the core pin 40 protrudes from the pin accommodating chamber (22, 25, 31), the relatively small-diameter tip portion 42 protrudes into the cavity C and serves as a mold component. On the other hand, the relatively large-diameter base end 41 occupies and closes the pin accommodating chamber. Thus, since the porous body 30 and the introduction path (23, 27) provided in the pin holder portion 20 are blocked from the cavity C, the molten metal is poured into the pin accommodating chamber (22, 25) when pouring into the cavity C. , 31) and the porous body 30 does not enter.

(Modification) The embodiment of the present invention may be modified as follows.
In the above embodiment, the porous body 30 is made of porous stainless steel. However, the porous body 30 may be made of other porous metals or porous ceramics. Examples of the porous metal that can be used include so-called foam metal. Foam metal is a porous metal body with a three-dimensional network structure that is manufactured by adding a gas generating substance to molten metal, or by attaching a metal around the skeleton of the foam resin and sintering it. Say. Specific examples of the foam metal include foam cast iron (porosity is usually about 3 to 40%). Examples of usable porous ceramics include silicon carbide sintered bodies and alumina sintered bodies, as well as those obtained by mixing a molding waste sand with a binder and a solvent and kneading and molding the molded article (the porosity is (Normally about 20 to 50%).

  In the above embodiment, when the release agent is applied to the entire outer peripheral surface of the core pin tip portion 42, the core pin 40 is lowered from the immersive position to the projecting position. When the 40 is moved backward from the protruding position (see FIG. 2) to the immersive position (see FIG. 1), the mixing valve or the like is opened to apply the mold release agent to the entire outer peripheral surface of the core pin tip 42. May be.

Sectional drawing of the principal part of the die apparatus for casting (at the time of pin immersion and mold opening). Sectional drawing of the principal part of the die apparatus for casting (at the time of pin protrusion and mold closing).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Fixed type | mold, 12 ... Movable type | mold (11 and 12 comprise a metal mold | die body), 20 ... Pin holder part, 22 ... Pin insertion hole of a holder main-body part, 23 ... Cylindrical channel | path of a holder main-body part, 25 ... Center hole of the lower lid part, 26... Recessed part of the lower lid part, 27... Conduit (23 and 27 constitute a release material and gas introduction path), 30. Central hole of body (22, 25, 31 constitutes pin accommodating chamber), 40 ... cast pin, 41 ... base end of cast pin, 42 ... tip of cast pin, C ... cavity.

Claims (4)

In a casting mold apparatus comprising a mold body that divides a cavity, a pin holder portion that holds a core pin so that it can protrude into and retract from the cavity, and a release agent coating mechanism provided in the pin holder portion. ,
The release agent coating mechanism includes an introduction path for introducing a release agent and a gas into the pin holder portion from the outside, and a porous body disposed in the vicinity of an outlet of the introduction path. The body has a ring shape and is provided so as to surround the outer peripheral surface of the core pin and to face the outer peripheral surface of the core pin to be coated in a non-contact state. Casting die equipment. In a casting mold apparatus comprising a mold body that divides a cavity, a pin holder portion that holds a core pin so that it can protrude into and retract from the cavity, and a release agent coating mechanism provided in the pin holder portion. ,
The release agent application mechanism includes an introduction path for introducing a release agent and gas from the outside into the pin holder portion, and a porous body disposed near an outlet of the introduction path,
The cast pin has a relatively large diameter proximal end and a relatively small diameter distal end,
Wherein the pin holder portion, the straight cylindrical pin receiving chamber having an inner diameter corresponding to the diameter of the proximal end portion of the core pin is formed, the core pin is held in the pin receiving chamber,
The porous body has a ring shape, and an inner peripheral surface thereof is provided so as to constitute an inner peripheral wall of the straight cylindrical pin accommodating chamber, and is applied to an outer peripheral surface of the core pin to be coated. Provided to face in a non-contact state,
A casting mold apparatus characterized by the above . A method of applying a release agent to a core pin constituting a casting mold apparatus,
A ring-shaped porous body was arranged in a non-contact state so as to surround the outer peripheral surface of the core pin to be coated, and a release agent and a gas were supplied to the porous body and passed through the porous body. A method for applying a release agent, which comprises applying a release agent to the surface of a core pin. 4. The method for applying a release agent according to claim 3 , wherein the release agent is a dispersion emulsion type release agent comprising water and a release component.

Images