JP2019042764A - Casting structure and casting method - Google Patents

Abstract

To provide a casting structure and a casting method in which the leakage-out of molten metal is prevented.SOLUTION: There is provided a casting structure 40 where a tube 32 is cast into a molded body 20, in which a projecting part 54A inserted into the tube 32 is formed at a mold 53 casting the molded body 20, and the outer periphery of the projecting part 54A is abutted against an inner peripheral face 32B of the tube 32 to seal a space between the mold 53 and the tube 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a casting structure and a casting method in which a pipe is cast into a molded body.

  Patent Document 1 discloses a casting heater in which an electric heating body and a metal tube are embedded in a casting portion.

  When casting the casting heater, an electric heating element, a metal tube, and the like are installed in the casting frame, the molten metal is filled into the casting frame, and the casting is formed by solidifying the molten metal.

JP 2002-31538 A

  However, when casting the casting heater, it is difficult to prevent a gap from being formed between the metal tube and the casting frame while the metal tube is installed on the casting frame. For this reason, when the molten metal pressurized by the die-casting method is filled in the casting frame, the molten metal may leak from the gap around the metal tube.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a casting structure and a casting method in which leakage of molten metal is prevented.

  According to an aspect of the present invention, a tube is cast into a molded body, and a convex portion to be inserted inside the tube is formed in a mold for casting the molded body, and an outer periphery of the convex portion. A casting structure is provided in which the space between the mold and the tube is sealed by contacting the inner peripheral surface of the tube.

  Further, according to an aspect of the present invention, there is provided a casting method for casting a tube into a molded body, wherein a convex portion to be inserted inside the tube is formed in a mold for casting the molded body, and the convex portion A casting method characterized by casting the molded body by filling a molten metal into the mold in a state where an outer periphery is brought into contact with an inner circumferential surface of the pipe and the mold and the pipe are sealed. Is provided.

  According to the above aspect, in the state where the convex portion of the mold is in contact with the inner peripheral surface of the tube and the space between the mold and the tube is sealed, the mold is filled with the molten metal and the molded body is cast. Since the molten metal thus filled is sealed inside the pipe, the molten metal is prevented from leaking outside the mold.

FIG. 1 is a cross-sectional view of a fluid heating apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the casting apparatus. FIG. 3 is a cross-sectional view of the casting structure. FIG. 4 is a cross-sectional view of a casting structure according to a comparative example.

  Hereinafter, a fluid heating apparatus 100 formed by a casting method according to an embodiment of the present invention will be described with reference to the drawings.

  First, the overall configuration of the fluid heating apparatus 100 will be described with reference to FIG. For simplification of description, the fluid heating device 100 is not illustrated in part.

  The fluid heating device 100 is applied to a vehicle air conditioner (not shown) mounted on a vehicle such as an EV (Electric Vehicle: electric vehicle) or an HEV (Hybrid Electric Vehicle: hybrid vehicle).

  The fluid heating device 100 includes a tank 10 through which a fluid flows and an electric heater unit 19 accommodated in the tank 10.

  The tank 10 includes an inner wall surface 14 that forms a fluid chamber 8, an opening 15 that opens upward and is assembled with a heater unit 19, a supply port 11 that is supplied with fluid, and a discharge port 12 that discharges fluid. Have.

  The heater unit 19 includes a spiral heater 30 that generates heat when energized, and a molded body 20 into which the heater 30 is cast.

  The heater 30 is a sheathed heater in which a nichrome wire (not shown) is wrapped with a pipe 32 through an insulating material 31. The heater 30 is not limited to this, and may be a PTC (Positive Temperature Coefficient) heater or another heater.

  The heater 30 has a pair of terminals 39 protruding from both ends of the tube 32. The heater 30 generates heat when the nichrome wire is energized through the terminal 39.

  The tube 32 of the heater 30 is made of a metal such as stainless steel. The formed body 20 is formed of, for example, an aluminum alloy as a metal having a lower melting point than that of the heater 30.

  The molded body 20 includes a heating part 22 in which the heater 30 is embedded, a top plate-like partition wall part 25 that closes the opening part 15 of the tank 10, and connection parts 24 and 28 that connect the heating part 22 to the partition part 25, Have

  The cylindrical heating unit 22 includes a plurality of inner peripheral fins 29 that protrude from the inner periphery to the fluid chamber 8 and a plurality of outer peripheral fins (not shown) that protrude from the outer periphery to the fluid chamber 8.

  When the fluid heating device 100 is manufactured, the heater unit 19 that is cast is assembled to the tank 10 as described later. Then, on the partition wall 25 of the heater unit 19, a cover (not shown) that forms the electrical chamber 9 is assembled after the electrical components and the circuit (not shown) are assembled. The fluid heating device 100 manufactured in this way is assembled into a vehicle air conditioner.

When the fluid heating apparatus 100 is operated, a fluid (hot water) as a medium of the vehicle air conditioner circulates as follows.
The fluid sent by the pump (not shown) is supplied from the supply port 11 to the fluid chamber 8 in the tank 10 through the pipe (not shown) as shown by the arrow A in FIG. To do.
Subsequently, as indicated by an arrow B, the fluid flows inside the heating unit 22 in the right direction in FIG. 1 and is heated by heat exchange with the inner peripheral fins 29.
Subsequently, as shown by arrow C, the fluid strikes the inner wall surface 14 of the tank 10 and changes its direction.
Subsequently, as shown by the arrow D, the fluid flows in the fluid chamber 8 in the left direction in FIG. 1 and is heated by heat exchange with the outer peripheral fins.
Subsequently, as shown by an arrow E, the fluid is discharged from the tank 10 through the discharge port 12.
Subsequently, the fluid is sent to a heater core (not shown) through a pipe (not shown), and warms air for air conditioning through the heater core.
Subsequently, the fluid that has passed through the heater core is sucked into the pump through a pipe (not shown) and circulated.
Thus, the fluid heating device 100 heats the fluid, whereby the heating operation of the vehicle air conditioner is executed.

  Next, with reference to FIG. 2 and FIG. 3, the casting process which casts the heater 30 in the molded object 20 is demonstrated.

  The molded body 20 is cast using a casting apparatus 50 shown in FIG. For simplification of description, the casting apparatus 50 is not illustrated in part.

  The casting apparatus 50 by the die casting method includes molds 51 to 53 that are filled with a pressurized molten metal.

  In the casting process, first, the heater 30 is installed on the mold 53.

  The mold 53 includes a pair of support portions 54 that support both end portions of the heater 30.

  As shown in FIG. 3, the support portion 54 includes a concave portion 54B that opens on the molding surface 53A of the mold 53, a step portion 54C that extends to the bottom of the concave portion 54B, and a convex portion 54A that protrudes to the back of the step portion 54C. And a hole 54D opened at the tip of the convex portion 54A. The concave portion 54B, the step portion 54C, the convex portion 54A, and the hole 54D are formed side by side on the same axis with the center line O as the center.

  On the other hand, at both ends of the heater 30, the pipe 32 extends in a cylindrical shape centered on the center line O. The tube 32 has an open end 32A that opens at the tip thereof, and a tapered (conical surface) inner peripheral surface 32B that increases in diameter toward the open end 32A.

  An annular sleeve 35 is fitted and joined to the outer periphery of the tube 32. The sleeve 35 has a tapered (conical surface) outer peripheral surface 35 </ b> A whose diameter decreases toward the open end 32 </ b> A of the tube 32.

In a state where the heater 30 is installed on the mold 53, the tube 32 of the heater 30 is supported on the support portion 54 of the mold 53 as follows.
The terminal 39 of the heater 30 is inserted into the hole 54D, and the end surface of the sleeve 35 contacts the stepped portion 54C. Accordingly, the tube 32 is supported at a predetermined position with respect to the support portion 54 with respect to the center line O.
At this time, the inner peripheral surface 32B of the tube 32 abuts on the outer periphery of the convex portion 54A in a planar shape. Thereby, the space between the inner peripheral surface 32B and the convex portion 54A is sealed. The tube 32 is supported at a position centered on the center line O with respect to the support portion 54.
At this time, the outer peripheral surface 35A of the sleeve 35 abuts on the inner periphery of the recess 54B in a planar shape. Thereby, the space between the outer peripheral surface 35A and the recess 54B is sealed. The tube 32 is supported at a position centering on the center line O via the sleeve 35.

  In the casting process, after both ends of the heater 30 are thus supported by the support portion 54 of the mold 53, the molds 51 to 53 are assembled, and the shaft-shaped mold 55 is inserted inside the spiral heater 30.

  Subsequently, in the casting process, the pressurized spray-like molten metal is filled into the molds 51 to 53 as indicated by arrows in FIGS. The molded body 20 is formed by solidifying the molten metal thus filled. Then, the molds 51 to 53 and 55 are separated from the molded body 20, and the molded body 20 is removed from the molds 51 to 53.

  The fluid heating device 100 is manufactured by assembling the heater unit 19 thus cast to the tank 10.

  Next, the effect of this embodiment will be described.

  According to this embodiment, the casting structure 40 by which the pipe | tube 32 is cast in the molded object 20 is provided. In the casting structure 40, an inner peripheral surface 32B facing the inside of the tube 32 is formed, a convex portion 54A inserted into the tube 32 is formed in a mold 53 for casting the molded body 20, and the outer periphery of the convex portion 54A is formed. The space between the mold 53 and the tube 32 is sealed by contacting the inner peripheral surface 32B.

  Further, according to the present embodiment, the mold 53 is filled with molten metal in a state where the outer periphery of the convex portion 54A is brought into contact with the inner peripheral surface 32B and the space between the mold 53 and the tube 32 is sealed. A casting method for casting 20 is provided.

  With this configuration, the mold 53 is filled with the molten metal in a state where the convex portion 54A of the mold 53 is in contact with the inner peripheral surface 32B of the tube 32 and the space between the mold 53 and the tube 32 is sealed. Thus, the molded body 20 is cast. Thus, since the molten metal to be filled is sealed inside the pipe 32, the molten metal is prevented from leaking outside the mold 53. Thereby, in the casting apparatus 50, since the leaked molten metal is prevented from adhering to each part outside the mold 53, maintenance is facilitated.

  Here, the casting structure 60 according to the comparative example shown in FIG. 4 will be described. In the casting structure 60, a straight cylindrical sleeve 37 is coupled to the outer periphery of the pipe 32, and the sleeve 37 is inserted into and supported by the recess 63 </ b> B of the mold 63. In this case, since the sealing portion between the tube 32 and the mold 63 is provided outside the sleeve 37, a gap is generated around the sleeve 37 and the tube 32, and the molten metal may leak out as indicated by the solid line arrow. .

  On the other hand, according to the present embodiment, a labyrinth-like sealing portion is provided between the outer periphery of the convex portion 54A of the mold 53 and the inner peripheral surface 32B of the tube 32, so that the molten metal is disposed inside the tube 32. Leaking out of the mold 53 through the mold 53 is effectively prevented.

  Further, according to the present embodiment, the casting structure 40 is provided in which the inner peripheral surface 32B is formed in a tapered shape whose diameter increases toward the opening end 32A.

  With this configuration, when the tube 32 moves in the axial direction (centerline O direction) and is installed on the mold 53, the tapered inner peripheral surface 32B is pressed against the outer periphery of the convex portion 54A of the mold 53. Be in close contact. Thereby, it is suppressed that a clearance gap arises between the internal peripheral surface 32B and the convex part 54A, and it is prevented that a molten metal leaks out.

  The inner peripheral surface 32B is not limited to the tapered shape, and may be formed in a right cylindrical shape.

  According to the present embodiment, the concave portion 54B into which the tube 32 is inserted is formed in the mold 53, the tapered outer peripheral surface 35A having a diameter reduced toward the concave portion 54B is formed in the tube 32, and the inner periphery of the concave portion 54B is the outer periphery. A cast-in structure 40 is provided in which the space between the mold 53 and the pipe 32 is sealed against the surface 35A.

  With this configuration, when the tube 32 moves in the axial direction and is installed in the mold 53, the tapered outer peripheral surface 35A is pressed against and closely contacts the inner periphery of the recess 54B of the mold 53. Thereby, it is suppressed that a clearance gap arises between the recessed part 54B and 35 A of outer peripheral surfaces, and it can prevent effectively that a molten metal leaks.

  The heater 21 is provided with a sleeve 35 that fits outside the tube 32, and an outer peripheral surface 35 </ b> A is formed on the sleeve 35. Not limited to this, the heater 21 may be configured such that the sleeve 35 is eliminated and the outer peripheral surface is integrally formed with the pipe 32.

  According to the present embodiment, the tube 32 is provided in the heater 30 that generates heat, and the molded body 20 is provided with the heater unit 19 that transmits the heat of the heater 30 to the fluid.

  By comprising in this way, the casting process which casts the heater 30 in the molded object 20 is performed efficiently.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  The present invention is suitable as a fluid heating device mounted on a vehicle, but can also be applied to a fluid heating device used other than a vehicle.

DESCRIPTION OF SYMBOLS 19 Heater unit 20 Molded body 30 Heater 32 Pipe 32A Open end 32B Inner peripheral surface 35A Outer peripheral surface 40 Casting structure 53 Mold 54A Convex part 54B Concave part

Claims (5)

A casting structure in which the tube is cast into the molded body,
A convex part to be inserted into the inside of the tube is formed in a mold for casting the molded body,
The casting structure is characterized in that an outer periphery of the convex portion abuts against an inner peripheral surface of the tube and a space between the mold and the tube is sealed. The cast structure according to claim 1,
The casting structure is characterized in that the inner peripheral surface is formed in a tapered shape whose diameter is increased toward the opening end of the pipe. The cast structure according to claim 1 or 2,
A recess is formed in the mold for inserting the tube,
A tapered outer peripheral surface that is reduced in diameter toward the recess is formed in the tube,
The casting structure is characterized in that an inner periphery of the concave portion abuts on the outer peripheral surface to seal between the mold and the tube. The casting structure according to any one of claims 1 to 3,
The tube is provided in a heater that generates heat,
The casting structure is provided in a heater unit that transmits heat of the heater to a fluid. A casting method for casting a tube into a molded body,
Forming a convex portion to be inserted inside the tube into a mold for casting the molded body;
The molded body is cast by filling the mold with molten metal in a state where the outer periphery of the convex portion is in contact with the inner peripheral surface of the tube and the space between the mold and the tube is sealed. Casting method.

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