JP6300361B2 - Casting equipment - Google Patents

Description

  The present invention relates to a casting apparatus.

  For example, a cast product having a complicated internal space shape, such as an aluminum alloy cylinder head that is one of engine parts, has conventionally been provided with a collapsible core in a mold cavity, And it is performed by “low pressure casting (LPDC)”. In this manufacturing method, after the casting is finished, the cast product is taken out from the mold, and then the core is broken to ensure a complicated internal space shape.

The collapsible core is shaped as a core by molding fine silica sand coated with resin (thermoplastic resin) around it into a shape corresponding to the internal space shape of the cast product, and curing the resin. Is done.
As a prior art of the casting apparatus using such a core, for example, those described in Patent Documents 1 and 2 can be cited.

JP 2011-110559 A JP 2009-131888 A

  At the time of casting, the core disposed in the cavity for molding the cast product comes into contact with a hot molten metal such as alloy aluminum to be filled. Then, the core resin undergoes thermal decomposition due to the high heat of the molten metal, and “core gas”, which is an organic gas, is generated. In general, the mold is provided with a gas vent pipe or the like, but conventionally, there is a problem that the core gas is liquefied in the gas vent pipe and stays as so-called “sag”.

  The present invention was created in order to solve the above-described problems, and efficiently recovers the spear from the gas generated from the core at the time of casting to reduce the spatter of the spear on the gas vent pipe. The purpose is to plan.

In order to solve the above problems, the present invention provides a casting apparatus in which a collapsible core is disposed in a cavity of a mold for casting, and a tip portion is located in the cavity, and gas generated from the core is generated. A gas recovery pin that communicates with a gas vent pin to be passed through and a base end portion of the gas vent pin, and has a cooling means for cooling the gas flowing in from the gas vent pin, and collects a part of the cooled gas as liquefied resin. And a spear collecting device comprising: a sealed box-shaped spear collecting box having a gas outlet formed in a side plate portion; an air pipe disposed in the spear collecting box to eject air; and the spear collecting box An annular negative pressure space having a gap L between the periphery of the end of the air tube and the cylinder. And the cooling means is By the negative pressure generated between the negative pressure of the yield device characterized by comprising the structure for cooling the gas.

  According to this casting apparatus, when the gas generated from the core touches the inside of the relatively low-temperature spear collecting device, it is liquefied and becomes spear and collected in the device. In addition, since the gas is cooled inside the apparatus, it is possible to efficiently collect the spear in the apparatus.

  According to this casting apparatus, the flow rate of the gas is increased by the negative pressure generated on the gas outlet side in the spear collecting device, and the gas is cooled, so that the spear can be recovered efficiently. Since negative pressure is generated on the gas outlet side, the cooling effect on the gas inlet side is lower than the cooling effect on the gas outlet side. Therefore, it is possible to reduce the adhesion of spear on the gas vent pin side.

  Further, according to the present invention, the gas inlet of the spear collecting device is formed at the bottom of the spear collecting device in the vertical direction so as to be positioned at the upper portion of the gas vent pin, and the upper portion of the gas inlet with respect to the horizontal direction. An intersecting intersection surface is formed, and the gas flowing in from the gas inlet is configured to flow downward along the intersection surface.

  According to this casting apparatus, by providing a crossing surface at the upper part of the gas inlet, dripping of the spear from the crossing surface can be prevented and inflow of the spear into the gas vent pin can be prevented.

  According to the present invention, it is possible to efficiently recover the sprout from the gas generated from the core at the time of casting, and to reduce the adhesion of the spear to the gas vent pipe or the like.

It is a side view of the casting apparatus which concerns on this invention. (A) is a top view of a spear collection | recovery apparatus, (b), (c) is the AA sectional view and BB sectional drawing in (a), respectively. It is a disassembled perspective view of a spear collection | recovery apparatus.

  In FIG. 1, a casting apparatus 1 includes a mold 2, a collapsible core 3, and a gas vent pin 4. The mold 2 includes an upper mold 2A, a plurality of horizontal molds 2B, and a lower mold 2C. The lower mold 2C attached to the lower mold 5C is fixed, and the upper mold 2A attached to the upper mold 5A is configured to be movable up and down, and the horizontal mold 2B attached to the horizontal mold 5B slides in the horizontal direction. It is configured freely. The lower mold 2 </ b> C is formed with a gate 7 for pouring the molten metal into the cavity 6 of the mold 2.

  In the cavity 6, a core 3 is disposed that is collapsed after molding of the cast product. The core 3 has a shape in which fine silica sand coated with a resin (thermoplastic resin) is made to correspond to the shape of the internal space of the cast product, and is shaped by curing the resin. The core 3 is disposed in the mold 2 when the mold 2 is open, and is positioned and held by the upper mold 2A, the horizontal mold 2B, and the lower mold 2C when the mold 2 is closed.

  The gas vent pin 4 is a pipe-like member for releasing the gas generated from the core 3 to the outside. The gas vent pin 4 of the present embodiment has a lower pin portion 8 that penetrates the upper mold 2A in the vertical direction and contacts the tip portion (lower end) so as to be slightly embedded in the core 3, and an upper end of the lower pin portion 8. The piping part 9 attached vertically is provided with an upper pin part 10 attached vertically to the upper end of the piping part 9. A gas vent channel 11 extending in the vertical direction is formed by the lower pin portion 8, the piping portion 9, and the upper pin portion 10. A flange portion 10A is formed on the outer peripheral surface in the middle of the height direction of the upper pin portion 10, and the compression coil spring 12 is fitted on the upper pin portion 10 so that the lower end is placed on the flange portion 10A. Has been. At the upper end of the compression coil spring 12, a ring plate-like cover plate 13 that is loosely fitted to the upper pin portion 10 is arranged.

The piping part 9 is located outside (upper) of the upper mold 2A. The pipe portion 9 is composed of a vertically long block piece having a substantially rectangular cross section. As described above, the gas vent channel 11 is formed inside and parallel to the gas vent channel 11. Thus, a heating hole 14 is formed. The heating hole 14 is perforated from the upper surface of the piping part 9, and the lower end thereof is stopped in the vicinity of the lower surface of the piping part 9 without penetrating. And the heater 15 is attached to the piping part 9 so that the one part may be inserted in the heating hole 14. FIG. Thereby, the heat from the heater 15 is transmitted to the gas flowing through the gas vent flow path 4 </ b> D through the heating hole 14 over substantially the entire height of the pipe portion 9. In addition, the lower pin part 8, the piping part 9, and the upper pin part 10 may be integrally assembled with each other, or may be integrally formed.
In addition, the number of the gas vent pins 4 is two in the present embodiment (in FIG. 1, the gas vent pins 4 on the back side are hidden), but may be one or three or more. Good.
In addition, when it is not necessary to heat the degassing pin 4, the heater 15 may not be provided.

"Spot collecting device 16"
The casting apparatus 1 has cooling means 17 (FIG. 2) that communicates with the base end portion of the gas vent pin 4 (the upper end of the upper pin portion 10) and cools the gas flowing in from the gas vent pin 4. A spear collecting device 16 is provided for recovering a part of the generated gas as liquefied spear.

  The spear collecting device 16 includes a spear collecting box 20 having a sealed box shape in which a gas inlet 18 is formed in a bottom plate portion and a gas outlet 19 is formed in a side plate portion. The spear recovery box 20 is placed and fixed to the lift table 23 by a bolt (not shown) via a bracket (not shown). 2 and 3, the crab collection box 20 has a horizontally long rectangular parallelepiped shape, and in this embodiment is divided into a lower body portion 21 and an upper lid portion 22 with a horizontal plane as a dividing plane.

  The main body 21 is a rectangular parallelepiped box with an opening formed at the top, and a flange portion 21A extends horizontally outward on the entire periphery of the upper edge. On the bottom plate 21 </ b> B of the main body portion 21, a cylindrical portion 21 </ b> C having no lid and no bottom is erected so as to protrude into the main body portion 21. The cylindrical portion 21 </ b> C is erected as a pair along the longitudinal direction of the main body portion 21. A cylindrical member 24 having no lid and no bottom is inserted into each cylindrical portion 21C from above. The cylindrical member 24 includes a cylindrical portion 24A inserted into the cylindrical portion 21C and a flange portion 24B formed on the upper edge of the cylindrical portion 24A. The flange portion 24B is formed on the upper edge of the cylindrical portion 21C. By abutting, it is loosely fitted to the cylindrical portion 21C so as not to fall. The lower end of the cylindrical member 24 protrudes downward from the bottom plate 21 </ b> B of the main body 21, and is in a state of being positioned below through the through hole formed in the lifting table 23. As shown in FIG. 1, the base end portion of the gas vent pin 4 is located in the vicinity of the lower end of the cylindrical member 24. That is, in this embodiment, the cylinder member 24 constitutes the gas inlet 18 that communicates with the gas vent pin 4.

  2 and 3, an inner box 25 having an upper surface formed in an inclined shape is disposed inside the main body 21. The inner box 25 is a horizontally long box along the longitudinal direction of the main body 21 and is formed of a substantially rectangular parallelepiped box with an opening formed in the lower portion. The inner box 25 surrounds the pair of cylindrical members 24 and has a bottom plate 21B. Placed on. The upper surface of the inner box 25 is formed as an inclined upper surface 25 </ b> A that is inclined in the short side direction of the inner box 25. A long hole 25B is formed near one end (the side where the gas outlet 19 is formed) in the longitudinal direction of the inclined upper surface 25A. As described above, the intersecting surface (inclined upper surface 25A) intersecting the horizontal direction is located immediately above the cylindrical member 24 constituting the gas inlet 18, and the long hole 25B is shifted to one end in the longitudinal direction with respect to the cylindrical member 24. Located.

"Cooling means 17"
The lid portion 22 is formed of a flat rectangular box with a lower opening, and a flange portion 22 </ b> A extends horizontally outward on the entire periphery of the lower edge. Of the pair of side surfaces 22B and 22C along the short side of the lid portion 22, a hose joint 26 is attached to one side surface 22B, and a circular hole is drilled coaxially with the hose joint 26 on the other side surface 22C. Yes. An air tube 27 extending along the longitudinal direction of the lid portion 22 is attached to the inside of the lid portion 22 so that the base end communicates with the hose joint 26. Inside the other side surface 22C, a lidless and bottomless cylindrical body 28 having an inner diameter larger than the outer diameter of the air tube 27 is fitted into the circular hole and fixed by welding or the like. The open end of the cylinder 28 facing the outside constitutes a gas outlet 19. The tip of the air tube 27 is located inside the cylinder 28 at a predetermined distance from the side surface 22C, and a gap L is formed between the outer surface around the tip of the air tube 27 and the inner surface of the cylinder 28. An annular negative pressure space 29 that faces the inside of the lid portion 22 is formed.

As described above, when air is blown from the hose 30 connected to the hose joint 26, the air escapes from the tip of the air pipe 27 through the gas outlet 19 to the outside as indicated by an arrow Q in FIG. Then, a negative pressure is generated in the narrow negative pressure space 29 by the momentum of the air blown from the tip of the air pipe 27, and the gas in the spear recovery box 20 is sucked into the negative pressure space 29 as indicated by an arrow P, and the gas outlet 19 is discharged. In the present embodiment, the negative pressure generated in the negative pressure space 29 constitutes the cooling means 17. The magnitude of the negative pressure generated in the negative pressure space 29 can be obtained by appropriately setting the diameter of the air tube 27 and the dimension of the gap L.
Further, in the present invention, the spear recovery box 20 is provided at a position separated from the mold 2, and when the gas flows into the spear recovery box 20, it is cooled by touching the housing of the spear recovery box 20. . Therefore, the spear collection box 20 itself also constitutes the cooling means 17.

  The main body portion 21 and the lid portion 22 having the above-described configuration are, for example, substantially fixed by being fastened with the bolts 31 and the nuts 32 while the flange portions 21A and 22A are applied so as to sandwich the flat partition plate 33. It is configured as a sealed spear collection box 20. The partition plate 33 is positioned above the inner box 25 so as to form a space with the inner box 25. A long hole 33A is formed in the vicinity of one end (the side where the hose joint 26 is attached) in the longitudinal direction of the partition plate 33. The long hole 33 </ b> A is shifted from the other end side in the longitudinal direction with respect to the cylindrical member 24.

  Further, the lid portion 22 is appropriately filled with a cotton-like spear adsorbent 34 for adsorbing spear components in the gas. In other words, the spear adsorbent 34 is packed so as to contact and surround the air pipe 27 extending along the longitudinal direction of the lid portion 22. The spear adsorbent 34 may be, for example, a cloth-like member, a felt member, a mesh metal member, or the like. The material is not particularly limited as long as it has predetermined air permeability. Further, the spear adsorbent 34 may be omitted.

"Action"
At the time of casting, the lifting table 23 is lowered and the lower end of the cylindrical member 24 is in contact with the lid plate 13. As a result, the gas inlet 18 communicates with the gas vent pin 4 in a sealed state. In addition, air is supplied to the air pipe 27 via the hose 30, and a negative pressure is generated in the negative pressure space 29.

  When molten metal flows from the gate 7 into the cavity 6 during casting, gas is generated from the core 3. The generated gas flows into the spear collection box 20 through the vent pin 4. Since the heater 15 is attached to the piping part 9 of the degassing pin 4, the gas is cooled and liquefied in the degassing pin 4, and the scum does not adhere to the degassing flow path 11.

  The gas flowing into the spear collection box 20 from the cylindrical member 24 is cooled by touching the housing of the spear collection box 20. For example, when the gas generated from the core 3 is cooled to about 200 ° C., it is liquefied and becomes crushed. Therefore, the gas is cooled by touching the varnish collection box 20 and the inner box 25 and adheres to the inner surfaces of these casings. . Specifically, the gas that has flowed upward into the spear collection box 20 from the cylindrical member 24 first strikes the inclined upper surface 25A of the inner box 25 and flows along the inclined upper surface 25A. As for the gas flow in the longitudinal direction of the spear collection box 20, as shown by the arrow R in FIG. 2B, the gas flows from the right side to the left side in the figure and exits upward from the long hole 25B.

  The gas that has passed through the long hole 25B then flows through the space between the inner box 25 and the partition plate 33 from the left side to the right side in the drawing as indicated by the arrow S, and then flows upward from the long hole 33A. The gas that has passed through the long hole 33A is removed from the spear adsorbent 34 by the spear adsorbent 34 and then flows from the right side to the left side in the drawing as indicated by the arrow P due to the negative pressure generated in the negative pressure space 29. 29 is sucked in and discharged from the gas outlet 19.

  As can be seen from the above, in the present embodiment, the maze structure is such that the gas flow path in the spear recovery box 20 is in the S direction opposite to the gas flow direction (P direction) at the gas outlet 19 at least once. It has become. With this structure, the length of the gas flow path in the spear recovery box 20 can be increased, so that the gas passage time becomes longer, and the spear is efficiently recovered in the limited inner space of the spear recovery box 20 accordingly. be able to.

  In the spear recovery box 20, the flow rate increases due to the negative pressure generated in the negative pressure space 29, that is, the negative pressure generated on the gas outlet 19 side, and the gas is efficiently cooled accordingly. The inventor initially tried to increase the gas flow rate and pump it by positive pressure near the gas inlet 18, that is, by blowing air. However, in this structure, although the gas flow rate was increased and the cooling effect was confirmed, it was found that the gas liquefies around the base end of the degassing pin 4 to be sprinkled and adhered to the degassing pin 4. Therefore, when the present inventor adopts a structure in which a negative pressure is generated on the gas outlet 19 side as in the present embodiment instead of pumping the gas on the gas inlet 18 side of the spear recovery box 20, the gas vent pin 4 It has been found that the gas can be efficiently liquefied in the spear recovery box 20 without liquefying the gas inside.

  Further, since the upper surface of the inner box 25 is inclined, the scum adhering to the inclined upper surface 25A flows to the lower end of the inclined upper surface 25A along the inclined upper surface 25A, and then travels along the side plate of the inner box 25 to the main body. It collects on the bottom plate 21B of the part 21. If the upper surface of the inner box 25 is a horizontal surface, the dust adhering to the upper surface may drop and enter the cylindrical member 24 (gas vent pin 4). Can be prevented, and the inflow of spider into the gas vent pin 4 can be prevented.

  In addition, about the spear collect | recovered with the spear collection | recovery box 20, for example, the spear recovery box 20 is removed periodically from the raising / lowering table 23, and it disassembles, and the main-body part 21, the cover part 22, the inner box 25, and the partition plate 33 are cleaned. To remove. As for the spear adsorbent 34, for example, the spear is cleaned or replaced with a new one.

The preferred embodiment of the present invention has been described above. The shape and structure of the spear collection box 20 and the structure of other members are not limited to those described in the drawings, and various design changes are possible.
As an example, the structure of the main body portion 21 has been described in the embodiment of the box body having a rectangular parallelepiped shape and a constant plate thickness. For example, the thickness of the box body is aimed at the cooling effect of cooling the housing of the spear recovery box 20 in the atmosphere. It may be made thin, made of copper alloy or aluminum alloy having a high thermal conductivity, or formed with cooling fins or irregular shapes to increase the surface area exposed to the atmosphere.

DESCRIPTION OF SYMBOLS 1 Casting apparatus 2 Mold 3 Core 4 Degassing pin 6 Cavity 8 Lower pin part 9 Piping part 10 Upper pin part 11 Degassing flow path 15 Heater 16 Jani collection | recovery apparatus 17 Cooling means 18 Gas inlet 19 Gas outlet 20 Jani collection box 21 Main body part 22 Lid part 25 Inner box 25A Inclined upper surface 29 Negative pressure space

Claims (2)

In a casting apparatus for casting by disposing a collapsible core in the mold cavity,
A degassing pin whose tip is located in the cavity and allows the gas generated from the core to pass through;
A spear collecting device that communicates with a base end portion of the vent pin and has cooling means for cooling the gas flowing in from the vent pin, and collects a part of the cooled gas as liquefied spear;
Equipped with a,
The spear collecting device is fixed to a sealed spear-shaped spear recovery box having a gas outlet formed in a side plate portion, an air pipe that is disposed in the spear recovery box and ejects air, and a gas outlet of the spear recovery box. A cylinder disposed outside the tip of the air tube,
An annular negative pressure space having a gap L between the tip of the air tube and the cylindrical body is formed,
The cooling means is
A casting apparatus , wherein the gas is cooled by a negative pressure generated in the negative pressure space of the spear collecting apparatus. The gas inlet of the spear collecting device is formed at the bottom of the spear collecting device in the vertical direction and is located at the top of the vent pin.
An intersection surface intersecting the horizontal direction is formed at the upper part of the gas inlet,
The casting apparatus according to claim 1 , wherein the gas flowing in from the gas inlet is configured to flow downward along the intersecting surface.

Images