JP2018149565A - Support structure of core pin in metal mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress displacement of a core pin when ejecting a molten metal.SOLUTION: A support structure 1 of a core pin 2 in a metal mold 5, has: the core pin 2 in which an insertion part 22 on one side in a longer direction is located in an internal space S of the metal mold 5 into which a molten metal M is poured, and a stem 21 on the other end side is supported by the metal mold 5; and a core pin 8 of which a tip 8a side, which is located in the internal space S of the metal mold 5 into which the molten metal is poured, is so located as to traverse a center axis Y1 of the core pin 2. The core pin 8 is provided with a recess 83 in which a tip 221 side of the core pin 2 is freely fitted from the center axis Y1 direction to form the support structure.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a support structure for a core pin in a mold.

  Patent Document 1 discloses a support structure for a core pin in a die casting mold.

Japanese Utility Model Publication No. 62-101654

As shown in FIG. 5, an internal space S corresponding to the shape of the casting is formed inside this type of die casting mold 200, and by injecting molten metal into the internal space S and solidifying it, A casting is produced.
The core pin 400 is used to form an oil passage in a casting manufactured using the die casting mold 200. In the die casting die 200, the core pin 400 is a region involved in the formation of the oil passage. (Insert portion 401) is provided in the internal space S.

  As shown in FIG. 5, when the core pin 400 is cantilevered by the die casting mold 200, the distal end 401 a side of the insertion portion 401 is a free end that can be displaced in the radial direction of the axis Y. It has become.

  Therefore, when the molten metal injected into the internal space S collides with the core pin 400 vigorously, the tip 401a side of the core pin 400 is displaced in the radial direction of the axis Y by a collision force resulting from the collision with the molten metal. There is.

  Here, as the length of the oil passage formed in the casting becomes longer, the length L in the axis Y direction of the insertion portion 401 of the casting pin 400 becomes longer, and the tip of the casting pin 400 when the molten metal collides. The degree of displacement on the 401a side increases.

When the degree of displacement on the tip 401a side of the core pin 400 becomes large, the tip 401a side of the core pin 400 may be cast in the molten state in a state of being displaced from the intended position. Will be formed in a shape different from the shape of the oil passage formed in the cast product.
Therefore, it is required to suppress the displacement of the core pin when the molten metal is injected.

The present invention
A first core pin in which one end side in the longitudinal direction is disposed in a space in which molten metal in the mold is poured, and the other end side is supported by the mold;
A second core pin that is disposed across the central axis of the first core pin, the tip side inserted into the space in which the molten metal in the mold is injected,
A structure for supporting a core pin in a mold, wherein the second core pin is provided with a recess in which one end of the first core pin is loosely fitted from the central axis direction. It was.

According to the present invention, one end of the first core pin is loosely fitted in the concave portion provided in the second core pin from the direction of the center axis of the first core pin. The tip of the cast pin can be displaced in the radial direction of the central axis only within the range surrounded by the inner periphery of the recess.
As a result, the tip side of the first core pin is greatly displaced in the radial direction of the central axis, and the shape of the oil passage formed in the casting by the first core pin is the planned shape. Can be suitably prevented from being formed in different shapes.

It is a figure explaining the side cover produced using the metal mold | die which employ | adopted the support structure of a cast pin. It is a figure explaining arrangement | positioning of the casting pin in a metal mold | die. It is a principal part enlarged view of a metal mold | die. It is a figure explaining the casting process of a side cover. It is a figure explaining the core pin concerning a prior art example.

  Hereinafter, an embodiment of the present invention will be described by taking as an example a case where a side cover 10 of an automatic transmission for a vehicle is manufactured by casting.

  FIG. 1 is a diagram illustrating a side cover 10 that is manufactured using a mold 5 that employs a support structure 1 for a core pin 2 according to an embodiment, and (a) is a plan view. (b) is AA sectional drawing in (a).

[Side cover 10]
As shown in FIG. 1A, a plurality of bolt holes 15 are provided in the peripheral portion of the side cover 10 at intervals in the circumferential direction, and the side cover 10 is a bolt that penetrates the bolt hole 15. (Not shown) is fixed to a transmission case (not shown) of a belt type continuously variable transmission.

As shown in FIG. 1B, an oil passage 12 that extends linearly over the substantially entire length in the width direction is formed inside the side cover 10.
The oil passages 13, 14 extending in the direction orthogonal to the oil passage 12 through the inside of the side cover 10 communicate with one end 121 and the other end 122 in the longitudinal direction of the oil passage 12.

Here, the side cover 10 is produced by casting.
For casting the side cover 10, a mold 5 (see FIG. 2) having an internal space S (cavity) corresponding to the shape of the side cover 10 is used.

[Mold 5]
FIG. 2 is a view for explaining the arrangement of the core pins 2 in the mold 5, and is a view showing a section of the mold 5 corresponding to the AA section of FIG.
FIG. 3 is an enlarged view of the main part of the mold, (a) is a diagram schematically explaining the AA cross section of FIG. 2, and (b) is the AA cross section in (a). It is a figure explaining typically.

As shown in FIG. 2, the mold 5 includes a fixed mold 6 and a movable mold 7 that are provided so as to be relatively displaceable in the direction of the axis X, and are made of die steel (high alloy tool steel) or high speed tool steel. It is formed in a box shape from an alloyed steel material.
In the mold 5, when the movable mold 7 is displaced in the axis X direction and joined to the fixed mold 6, an internal space S corresponding to the shape of the side cover 10 is formed between the movable mold 7 and the fixed mold 6. .
The side cover 10 is produced by injecting and solidifying a molten material (for example, aluminum alloy) constituting the side cover 10 into the internal space S of the mold 5.

  In the mold 5, a fixed mold 6 disposed on the upper side in the figure and a movable mold 7 disposed on the lower side in the figure are disposed to face each other in the direction of the axis X, and the movable mold 7 is not shown in the drawing. Thus, the movable mold 7 comes into contact with and is separated from the fixed mold 6 by being displaced in the direction of the axis X.

  In the movable mold 7, a convex portion 710 corresponding to the shape of the side cover 10 is provided on the surface 70 facing the fixed mold 6. In the fixed mold 6, the side cover 10 is disposed on the facing surface 60 facing the movable mold 7. A recess 610 corresponding to the shape is formed.

  When the movable mold 7 and the fixed mold 6 are joined, the convex portion 710 of the movable mold 7 is inserted into the concave section 610 of the fixed mold 6, and the side cover 10 is interposed between the movable mold 7 and the fixed mold 6. An internal space S corresponding to the shape is formed.

A casting pin 2 for forming an oil passage 12 is set in the casting (side cover 10) in the fixed die 6, and an insertion hole 620 of the casting pin 2 connects the fixed die 6 to the axis Y. It is provided penetrating in the direction.
The insertion hole 620 opens to the inner periphery of the recess 610. When the core pin 2 is inserted into the insertion hole 620, the core pin 2 has a central axis Y1 along the longitudinal direction of the core pin 2, It is arranged in an orientation along an axis Y that is orthogonal to the axis X.

  The core pin 2 has an outer diameter base portion 21 that matches the inner diameter of the insertion hole 620, and the core pin 2 is fitted into the fixed die 6 by fitting the base portion 21 into the inner periphery of the insertion hole 620. It is set.

  In the core pin 2, an insertion portion 22 that is inserted into the internal space S is formed integrally with the base portion 21. The insertion portion 22 is a shaft-like member having a circular cross-sectional shape, and the insertion portion 22 has a tapered shape in which the outer diameter D1 decreases as the distance from the base portion 21 increases.

  The core pin 2 is cantilevered by a fixed die 6, and the distal end 221 side of the insertion portion 22 can be displaced in the radial direction of the central axis Y1 with the base portion 21 supported by the fixed die 6 as a fulcrum. ing.

  In the internal space S of the mold 5, the insertion portion 22 of the core pin 2 is provided over substantially the entire length in the width direction of the internal space S (the left-right direction in FIG. 2). The insertion portions 82 and 92 side of the core pins 8 and 9 set on the movable mold 7 are also inserted.

  In the internal space S, the insertion portions 82 and 92 of the core pins 8 and 9 are provided at intervals in the axis Y direction, and the insertion portion 22 of the core pin 2 extends from one core pin 9 protruding into the internal space S. It has a length L1 in the axis Y direction extending to the other core pin 8.

  The distal end 221 of the insertion portion 22 is a flat surface orthogonal to the central axis Y 1, and the distal end 221 side of the insertion portion 22 is loosely fitted in the recess 83 of the core pin 8 set in the movable die 7.

The movable mold 7 is provided with insertion holes 71 and 72 into which the core pins 8 and 9 are inserted. The insertion holes 71 and 72 respectively penetrate the movable mold 7 in the axis X direction, and are provided at intervals in the axis Y direction orthogonal to the axis X.
The insertion holes 71 and 72 are formed by connecting large-diameter portions 711 and 721 and small-diameter portions 712 and 722 in series in the directions of the central axes X1 and X2, respectively.

  The core pins 8 and 9 inserted into the insertion holes 71 and 72 have an outer diameter base portion 81 and 91 that matches the inner diameter of the large diameter portions 711 and 721 and an outer diameter insertion portion that matches the inner diameter of the small diameter portions 712 and 722. 82, 92.

The core pins 8 and 9 are set in the movable die 7 by inserting the tips 8a and 9a side of the core pins 8 and 9 into the insertion holes 71 and 72 from the axis X direction.
In this state, the core pins 8 and 9 are supported by the movable die 7 in such a direction that the central axes X1 and X2 of the core pins 8 and 9 are along the axis X that is the moving direction of the movable die 7.

  The core pins 8 and 9 are provided so that the distal ends 8 a and 9 a of the insertion portions 82 and 92 protrude into the internal space S of the mold 5. The insertion portions 82 and 92 are shaft-shaped members having a circular cross-sectional shape, and the regions protruding into the internal space S in the insertion portions 82 and 92 have a shape in which the outer diameter decreases toward the distal ends 8a and 9a. doing.

  The tip 9a of the core pin 9 is opposed to the outer periphery of the core pin 2 arranged in the direction perpendicular to the central axes X1 and X2 in the inner space S of the mold 5 with a gap.

  The tip 8a side of the core pin 8 reaches a position crossing the central axis Y1 of the core pin 2 in the internal space S of the mold 5, and the tip 221 of the core pin 2 and the tip 221 of the core pin 8 are reached. A concavity 83 for avoiding interference with the insertion portion 22 of the core pin 2 is provided in the facing portion.

  As shown in FIG. 2, in a cross-sectional view along the central axes X1 and Y1 orthogonal to each other, the recess 83 has the central axis Y1 on the base 81 side (lower side in FIG. 2) of the core pin 8 from the tip 8a of the core pin 8. It is provided over the span.

The recess 83 has a flat surface 831 facing the tip 221 of the core pin 2, and the flat surface 831 is provided along the central axis X 1 of the core pin 8.
The flat surface 831 is provided to avoid interference between the core pin 8 supported by the fixed die 6 and the core pin 8 supported by the movable die 7, and between the tip 221 of the core pin 2. A gap S1 is secured.

  As shown in FIGS. 3A and 3B, the recess 83 has an arc-shaped groove 832 that surrounds the outer periphery of the insertion portion 22 of the core pin 2 on the tip 221 side with a gap S2. In the core pin 8, the arc-shaped groove 832 is located on the base 81 side (lower side in FIG. 2) with respect to the central axis Y1.

As shown in FIG. 3A, the arc-shaped groove 832 is formed with a radius of curvature R larger than the radius of curvature r of the outer periphery 222 of the insertion portion 22 of the core pin 2 when viewed from the direction of the central axis Y1.
The opening width La of the arc-shaped groove 832 is larger than the outer diameter Da of the insertion portion 22 of the core pin 2.
Therefore, a clearance S <b> 2 is also secured between the outer periphery of the insertion portion 22 of the core pin 2 and the inner periphery of the arc-shaped groove 832.

  The arc-shaped groove 832 as viewed from the direction of the central axis Y1 is provided closer to the base 81 side of the core pin 8 than the axis Z orthogonal to the central axis Y1 and the central axis X1, and the arc-shaped groove 832 in the radial direction of the central axis X1. On both sides, flat portions 833 and 833 parallel to the tip 8a of the core pin 8 are provided.

The distal end 221 side of the insertion portion 22 of the core pin 2 is displaced toward the base 81 side (lower side in FIG. 3A) of the core pin 8 in the direction of the central axis X1, and in the axis Z direction (FIG. 3B). ) In the vertical direction) is restricted by the arc-shaped groove 832.
This arc-shaped groove 832 constitutes a regulating wall that regulates the displacement of the insertion portion 22 of the core pin 2 on the distal end 221 side.

  Further, in the recess 83 of the core pin 8, the tip 221 side of the insertion portion 22 of the core pin 2 is loosely fitted, and interference between the core pin 8 and the core pin 8 in the mold 5 is prevented.

[Production of Side Cover 10]
Hereinafter, a method of creating the side cover 10 that is produced using the mold 5 that employs the support structure 1 of the core pin 2 according to the embodiment will be described with reference to FIG.
FIG. 4 is a diagram for explaining a process for manufacturing the side cover 10.
FIG. 4A is a schematic diagram showing a state in which the fixed mold 6 and the movable mold 7 are assembled and an internal space S corresponding to the shape of the side cover 10 is formed in the internal space S of the mold 5. .
FIG. 4B is a schematic diagram showing a state in which the molten metal M is injected into the internal space S of the mold 5.
FIG. 4C is a schematic diagram showing removal of the core pin 2 from the mold 5.
4 (d) shows a cast product (side cover intermediate) from the movable die 7 after the movable die 7 is displaced in a direction away from the fixed die 6 (lower side in FIG. 4 (d)). It is a schematic diagram which shows the process of taking out goods 10 ').
FIG. 4E is a diagram schematically showing the side cover 10 finally obtained.

  First, as shown in FIG. 4A, the fixed mold 6 and the movable mold 7 are assembled to form an internal space S corresponding to the side cover 10 inside the mold 5. In this state, core pins 8 and 9 for forming oil passages 13 and 14 of the side cover 10 are attached to the movable die 7, and an oil passage 12 of the side cover 10 is formed on the fixed die 6. The cast pin 2 is attached later.

In the state of FIG. 4A, for example, molten metal M of aluminum alloy is injected into the internal space S of the mold 5 from an injection port (not shown) of the molten metal M provided in the mold.
As a result, the molten metal M is vigorously injected into the internal space S of the mold 5 and filled with the molten metal M injected into the internal space S.
As a result, the insertion portions 82 and 92 of the core pins 8 and 9 and the insertion portion 22 of the core pin 2 are cast into the molten metal M (see FIG. 4B).

  As shown in (c) of FIG. 4, after the molten metal M injected into the internal space S is solidified, the core pin 2 is moved in the direction of the central axis Y <b> 1 to be detached from the insertion hole 620 of the fixed mold 6. As a result, the oil passage 12 'is formed in the cast product (side cover intermediate product 10').

Then, as shown in FIG. 4 (d), the movable mold 7 is moved in the direction away from the fixed mold 6 (downward in the figure) to open the mold, and then the movable cover 7 is moved to the side cover intermediate product. Leave 10 '.
Here, in the side cover intermediate product 10 ′, the oil passage 12 ′ does not communicate with the oil passages 13 ′ and 14 ′.

  Therefore, the side cover 10 is finally manufactured by performing drilling for communicating the oil passages 13 ′, 14 ′ with the oil passage 12 ′ (see FIG. 4E).

  Here, when the molten metal M is injected into the internal space S of the mold 5 and the injected molten metal M acts on a region where the concave portion 83 of the core pin 8 and the tip 221 of the core pin 2 are loosely fitted, the core pin 8 The stress caused by the collision with the molten metal M acts on the tip 8a side of the steel and the tip 221 side of the core pin 2.

As described above, the core pin 2 is cantilevered by the fixed die 6 of the die 5, and the front end 221 side serving as a free end is loosely fitted in the recess 83 of the core pin 8 from the direction of the central axis Y <b> 1. .
Therefore, the tip 221 side of the core pin 2 is disposed in the internal space S of the mold 5 in a state in which it can be displaced in the radial direction of the central axis Y1 of the core pin 2.

  Therefore, when a stress caused by the collision with the molten metal M acts on the tip 221 side of the core pin 2, this stress acts in a direction to displace the tip 221 side of the core pin 2 in the radial direction of the central axis Y1. To do.

Here, the recess 83 of the core pin 8 is provided with an arc-shaped groove 832 that surrounds the outer periphery 222 on the tip 221 side of the core pin 2 at a predetermined interval (see FIG. 3A).
For this reason, the distal end 221 side of the insertion portion 22 of the core pin 2 is displaced toward the base 81 side of the core pin 8 in the direction of the central axis X1 (downward in FIG. The displacement in the vertical direction (refer to the arrow in FIG. 3B) is regulated within the range of the gap S2 with the inner periphery of the arc-shaped groove 832.

  Therefore, the tip 221 side of the core pin 2 is greatly displaced in the radial direction of the central axis Y1, and the shape of the oil passage 12 formed in the side cover 10 by the core pin 2 is different from the expected shape. It can prevent suitably forming in a shape.

Furthermore, since the positional relationship between the tip 221 side of the core pin 2 and the tip 8a side of the core pin 8 does not deviate greatly in the axis Z direction from the planned positional relationship, the side cover intermediate obtained by casting In the product 10 ′, it is possible to suitably prevent the oil passage 12 ′ from being positioned on the extension of the oil passage 13 ′.
If the oil passage 12 ′ is not positioned on the extension of the oil passage 13 ′, the oil passage 13 ′ and the oil passage 12 ′ cannot be communicated during drilling. Can be prevented.

  Further, when the movable die 7 is joined to the fixed die 6 and then the insertion portion 22 of the core pin 2 is inserted into the internal space S of the die 5, the core pin located on the central axis Y1 of the core pin 2 8, the distal end 221 side of the insertion portion 22 is loosely fitted from the direction of the central axis Y1.

Therefore, when the core pin 2 is inserted into the internal space S, it can be suitably prevented that the core pin 8 interferes with the core pin 8.
Thereby, due to the interference between the core pin 2 and the core pin 8, the tip 221 side of the core pin 2 is not greatly deformed.
Therefore, the shape of the oil passage 12 formed in the side cover 10 by the core pin 2 is formed in a shape different from the expected shape due to the interference between the core pin 2 and the core pin 8. Can be suitably prevented.

Further, on the tip 8a side of the core pin 8, a recess 83 is opened in a direction facing the insertion portion 22 of the core pin 2, and the recess 83 crosses the central axis Y1 from the tip 8a of the core pin 8 to the base 81 side. Formed in the range.
Therefore, even after the insertion portion 22 of the core pin 2 is arranged in the internal space S, the inserted core pin 8 interferes with the core pin 2 even if the tip 8a side of the core pin 8 is inserted into the internal space S. And it can prevent suitably that the core pin 2 and the core pin 8 are arrange | positioned in the position remove | deviated from the position which was planned.

As described above, in the embodiment,
(1) Casting in which the insertion portion 22 on one end side in the longitudinal direction is disposed in the internal space S into which the molten metal M in the mold 5 is poured, and the base portion 21 on the other end side is supported by the mold 5 Pin 2 (first core pin),
A core pin 8 (second cast pin) disposed so that the tip 8a side disposed in the internal space S into which the molten metal M in the mold 5 is poured crosses the central axis Y1 of the cast pin 2. Have
The core pin 8 is provided with a recess 83 in which the tip 221 side of the core pin 2 is loosely fitted from the direction of the central axis Y1.

If comprised in this way, the front-end | tip 221 side of the core pin 2 is loosely fitted in the recessed part 83 provided in the core pin 8 from the central axis Y1 direction along the longitudinal direction of the core pin 2, and the front-end | tip of the core pin 2 is carried out. The 221 side can be displaced in the radial direction of the central axis Y <b> 1 only within the range surrounded by the inner periphery of the recess 83.
As a result, the tip 221 side of the core pin 2 is greatly displaced in the radial direction of the central axis Y1, and the shape of the oil passage 12 formed in the side cover 10 (cast product) by the core pin 2 is planned. It can prevent suitably that it forms with the shape different from the shape which it had.

(2) The core pin 8 is arranged at a position where the tip 8a side of the core pin 8 intersects the central axis Y1 of the core pin 2,
On the outer periphery on the tip 8a side of the core pin 8, a recess 83 is provided with the opening directed in the direction of the central axis Y1 of the core pin 2,
The concave portion 83 as viewed from the direction of the center axis Y1 of the core pin 2 has a configuration in which the center axis Y1 of the core pin 8 extends from the tip 8a of the core pin 8 to the base 81 side of the core pin 8. .

If comprised in this way, when the insertion part 22 of the casting pin 2 is inserted in the interior space S of the metal mold | die 5, the front-end | tip 8a side of the core pin 8 arrange | positioned in the interior space S, and casting It can prevent suitably that the front-end | tip 221 side of the pin 2 interferes.
Thereby, due to the interference between the core pin 2 and the core pin 8, the tip 221 side of the core pin 2 is greatly deformed, and the shape of the oil passage 12 formed in the side cover 10 by the core pin 2 is changed. Further, it is possible to suitably prevent the formation of a shape different from the planned shape.

The insertion part 22 of the core pin 2 has a circular cross-sectional shape at least on the tip 221 side,
The recess 83 of the core pin 8 is configured to have an arc-shaped groove 832 (regulation wall having an arc-shaped inner periphery) along the outer periphery 222 on the tip 221 side of the core pin 8 on the base 81 side.

If comprised in this way, the front-end | tip 221 side of the insertion part 22 of the core pin 2 will be displaced to the base 81 side of the core pin 8 in the direction of the central axis X1 (lower side in FIG. 3A: see arrow), Displacement in the axis Z direction (vertical direction in FIG. 3B: see arrow) is restricted within the range of the gap S2 with the inner periphery of the arc-shaped groove 832.
Therefore, the tip 221 side of the core pin 2 is greatly displaced in the radial direction of the central axis Y1, and the shape of the oil passage 12 formed in the side cover 10 by the core pin 2 is different from the expected shape. It can prevent suitably forming in a shape.

The arc-shaped groove 832 viewed from the direction of the central axis Y1 of the core pin 2 is
It is provided closer to the base 81 side of the core pin 8 than the axis Z (virtual line) orthogonal to the central axis Y1 of the core pin 2 and the central axis X1 of the core pin 8;
The tip 8a side of the core pin 8 with respect to the axis Z is configured to be cut out along the central axis Y1 of the core pin 8.

  If comprised in this way, even if it inserts the front-end | tip 8a side of the core pin 8 in the internal space S after arrange | positioning the insertion part 22 of the core pin 2 in the internal space S, the inserted core pin 8 is cast. It is possible to suitably prevent the core pin 2 and the core pin 8 from being arranged at a position deviating from the planned position by interfering with the pin 2.

DESCRIPTION OF SYMBOLS 1 Support structure 2 Cast pin 21 Base part 22 Insertion part 221 Tip end 222 Outer circumference 5 Mold 6 Fixed mold 610 Concave part 620 Insertion hole 7 Movable mold 710 Convex part 8, 9 Core pin 8a, 9a Tip part 81, 91 Base part 82, 92 Insertion part 83 Concave portion 10 Side cover 10 'Side cover intermediate product 12, 13 Oil passage 71, 72 Insertion hole 711, 721 Large diameter portion 712, 722 Small diameter portion 831 Flat surface 832 Arc-shaped groove 833 Flat portion M Molten metal R, r Curvature radius S Internal Space S1 Clearance S2 Clearance X Axis X1 Central Axis Y Y Axis Y1 Central Axis Z Axis

Claims (4)

A first core pin in which one end side in the longitudinal direction is disposed in a space in which molten metal in the mold is poured, and the other end side is supported by the mold;
A front end side disposed in a space in which molten metal in the mold is poured, and a second core pin that is disposed across the central axis of the first core pin,
A cast pin in a mold, wherein the second cast pin is provided with a recess in which one end of the first cast pin is loosely fitted from the center axis direction of the first cast pin. Support structure. The second core pin is arranged at a position where the tip side of the second core pin intersects the central axis of the first core pin,
In the outer periphery on the tip side of the second core pin, the concave portion is provided with the opening directed in the central axis direction of the first core pin,
When viewed from the central axis direction of the first core pin, the concave portion extends from the tip end of the second core pin to the base axis side of the second core pin. The support structure for a core pin in a mold according to claim 1, wherein the support structure is provided in a straddling range. The one end side of the first core pin has a circular cross-sectional shape,
The concave portion of the second cast pin has a regulating wall having an arc-shaped inner periphery along the outer periphery on the one end side on the proximal end side of the second cast pin. Item 3. A cast pin support structure in the mold according to Item 2. The support wall as viewed from the direction of the central axis of the first core pin,
A base line side of the second punching pin is provided with respect to a virtual line perpendicular to the central axis line of the first core pin and the central axis of the second core pin;
4. The cast pin support structure in a mold according to claim 3, wherein a tip end side of the second punch pin is cut away from the virtual line.

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