JP5412386B2 - Thin-walled bottomed cylindrical metal member and manufacturing method thereof - Google Patents

Description

  The present invention relates to a thin-walled cylindrical metal member such as a core pin (core pin) used for die casting, injection molding, and the like, and a method for manufacturing the same.

Generally, a core pin (core pin) fixed to a mold is used to form a hole such as a bolt hole in a die-cast product or the like. The core pin is a metal round bar, and there are a hollow one in which a cooling hole is formed along the central axis and a solid one in which no cooling hole is formed. The following Patent Document 1 discloses a core pin in which a cooling hole is formed.
The use of the core pin in which the cooling hole is formed is advantageous in that the shrinkage nest generated in the die-cast product can be moved away from the core pin position.

Japanese Patent Laid-Open No. 9-1313

  However, the cooling hole is generally drilled, and in that case, the inner peripheral surface of the core pin forming the cooling hole is scratched by the drill blade (small irregularities are created), and there is The cooling water may stay, the inner peripheral surface of the core pin may be oxidized, and rust may be generated on the inner peripheral surface of the core pin. Moreover, if this rust progresses remarkably, cracks and cracks will occur in the thickness direction of the core pin, and coolant such as water passing through the cooling holes may leak out.

  The present invention has been made in view of the above circumstances, and can prevent the inner peripheral surface of the core pin from being oxidized and rusting from occurring on the inner peripheral surface of the core pin, and in the thickness direction of the core pin. It is an object of the present invention to provide a thin-walled cylindrical metal member having a bottom and a method of manufacturing the same, which can prevent a coolant such as water passing through a cooling hole from leaking to the outside due to the occurrence of cracks and cracks.

The present invention employs the following means in order to solve the above problems.
A thin-walled cylindrical metal member according to the present invention includes an outer cylinder made of metal and a cooling hole that is housed in the outer cylinder and has a bottomed hole at the tip. An inner cylinder made of stainless steel , and a hole having an inner diameter such that the difference from the outer diameter of the inner cylinder is 0.01 mm to 0.09 mm is formed along the central axis of the outer cylinder A thin-walled cylindrical metal member that is formed, wherein the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder are applied to the entire outer peripheral surface of the inner cylinder, A solution in which water and a flux are mixed at a predetermined ratio is heated at a temperature higher than the melting temperature of the silver wax, and then cooled through water or oil. Bonded in close contact.

The manufacturing method of a thin-walled cylindrical metal member according to the present invention includes an outer tube made of metal, and cooling that is housed in the outer tube and has a bottomed hole that has a bottom at the tip. A method of manufacturing a thin-walled cylindrical metal member having an inner cylinder made of metal in which a hole is formed, wherein the inner diameter has a difference from the outer diameter of the inner cylinder of 0.01 mm to 0.09 mm. A hole having a hole is formed along the central axis of the outer cylinder, and a solution in which powdery brazing material, water, and flux are mixed at a predetermined ratio is applied to the entire outer peripheral surface of the inner cylinder. Then, the inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder, and the outer cylinder into which the inner cylinder is inserted is inserted into the brazing material. After heating at a temperature higher than the dissolution temperature, cooling was performed in water or oil.

The manufacturing method of a thin-walled cylindrical metal member according to the present invention includes an outer tube made of metal, and cooling that is housed in the outer tube and has a bottomed hole that has a bottom at the tip. A method of manufacturing a thin-walled cylindrical metal member having an inner cylinder made of stainless steel in which a hole is formed, wherein the inner diameter has a difference from the outer diameter of the inner cylinder of 0.01 mm to 0.09 mm. A hole having a hole is formed along the central axis of the outer cylinder, and a solution in which powdery silver solder, water, and flux are mixed at a predetermined ratio is applied to the entire outer peripheral surface of the inner cylinder. Then, the inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder, and the outer cylinder in which the inner cylinder is inserted is After heating at a temperature higher than the dissolution temperature, cooling was performed in water or oil.

According to the manufacturing method of the thin-walled cylindrical metal member or the thin-walled cylindrical metal member according to the present invention, the inner peripheral surface of the outer cylinder is covered with the inner cylinder made of rust-resistant stainless steel, and the water flowing into the cooling hole The coolant does not contact the inner peripheral surface of the outer cylinder.
As a result, it is possible to prevent the inner peripheral surface of the thin-walled cylindrical metal member from being oxidized and rusting from occurring on the inner peripheral surface of the thin-walled cylindrical metal member. It is possible to prevent cracks and cracks from occurring in the thickness direction and leakage of coolant such as water passing through the cooling holes.
In addition, the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder are joined in close contact with each other via silver solder, and the outer cylinder is efficiently cooled by a coolant such as water. The seizure of the bottom cylindrical metal member can be prevented and the shrinkage nest generated in the die-cast product can be kept away from the thin-walled cylindrical metal member position.

  In the thin-walled cylindrical metal member with a bottom, it is more preferable that the inner cylinder has a thickness of 0.1 mm to 0.15 mm.

According to such a thin bottomed cylindrical metal member, the inner cylinder has a very thin wall thickness of 0.1 mm to 0.15 mm. Therefore, it is necessary to increase the inner diameter and the outer diameter of the outer cylinder by the thickness of the inner cylinder. However, it is possible to prevent the diameter from expanding outward in the radial direction.
Also, the inner cylinder is very thin, 0.1 mm to 0.15 mm, and the cooling effect by coolant such as water flowing into the cooling hole is almost the same as that of a conventional thin-walled cylindrical metal member having no inner cylinder. Since it will be maintained at the same level, it is possible to improve the conventional thin-walled cylindrical metal member by inserting the inner cylinder into the cooling hole of the conventional thin-walled cylindrical metal member without the inner cylinder. it can.

The manufacturing method of a thin-walled cylindrical metal member according to the present invention includes an outer tube made of metal, and cooling that is housed in the outer tube and has a bottomed hole that has a bottom at the tip. A method of manufacturing a thin-walled cylindrical metal member having an inner cylinder made of metal in which a hole is formed, wherein the inner diameter has a difference from the outer diameter of the inner cylinder of 0.01 mm to 0.09 mm. A hole having a hole formed along the central axis of the outer cylinder, and a solution in which powdered BAg8 and water are mixed in a predetermined ratio is applied to the entire outer peripheral surface of the inner cylinder; The inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder, and the outer cylinder in which the inner cylinder is inserted is inserted into the BAg8 in a vacuum heat treatment furnace. After heating at a temperature higher than the dissolution temperature, cooling was performed in water or oil.

The manufacturing method of a thin-walled cylindrical metal member according to the present invention includes an outer tube made of metal, and cooling that is housed in the outer tube and has a bottomed hole that has a bottom at the tip. A method of manufacturing a thin-walled cylindrical metal member having an inner cylinder made of stainless steel in which a hole is formed, wherein the inner diameter has a difference from the outer diameter of the inner cylinder of 0.01 mm to 0.09 mm. A hole having a hole formed along the central axis of the outer cylinder, and a solution in which powdered BAg8 and water are mixed in a predetermined ratio is applied to the entire outer peripheral surface of the inner cylinder; The inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder, and the outer cylinder in which the inner cylinder is inserted is inserted into the BAg8 in a vacuum heat treatment furnace. After heating at a temperature higher than the dissolution temperature, cooling was performed in water or oil.

According to the method for manufacturing a thin-walled cylindrical metal member according to the present invention, generation of gas during vacuum heat treatment is eliminated, so that the core pin can be manufactured using a vacuum heat treatment furnace.
Further, the inner peripheral surface of the outer cylinder is covered with an inner cylinder made of rust-resistant stainless steel so that coolant such as water flowing into the cooling hole does not contact the inner peripheral surface of the outer cylinder.
As a result, it is possible to prevent the inner peripheral surface of the thin-walled cylindrical metal member from being oxidized and rusting from occurring on the inner peripheral surface of the thin-walled cylindrical metal member. It is possible to prevent cracks and cracks from occurring in the thickness direction and leakage of coolant such as water passing through the cooling holes.
Furthermore, since the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder are joined in close contact with each other via BAg8, the outer cylinder is efficiently cooled by a coolant such as water. It is possible to prevent seizure of the cylindrical metal member and to keep the shrinkage nest generated in the die-cast product away from the position of the thin-walled cylindrical metal member.

  In the manufacturing method of the thin-walled cylindrical metal member or the thin-walled cylindrical metal member, it is more preferable that the thin-walled cylindrical metal member is a core pin used in a die casting die.

  According to such a thin bottomed cylindrical metal member or a manufacturing method of a thin bottomed cylindrical metal member, the bottomed hole formed in the core pin is used as a cooling hole for cooling by supplying a coolant such as water. Since leakage of coolant such as water passing through the cooling hole is prevented, the yield of the die-cast product can be improved.

  According to the manufacturing method of the thin-walled cylindrical metal member or the thin-walled cylindrical metal member according to the present invention, the inner peripheral surface of the thin-walled cylindrical metal member is oxidized, and the inner peripheral surface of the thin-walled cylindrical metal member is rusted. Can be prevented, and cracks and cracks are generated in the thickness direction of the thin-walled cylindrical metal member, preventing coolant and other coolant from passing through the cooling holes from leaking outside. There is an effect that can be done.

It is a sectional side view which shows the state which attached the core pin (thin walled cylindrical metal member) to the die-casting die. It is sectional drawing of a core pin. It is the figure which showed the manufacturing method of the core pin which concerns on one Embodiment of this invention.

Hereinafter, a thin-walled cylindrical metal member and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a core pin (core pin) used for a die casting mold is taken as an example of a thin-walled bottomed cylindrical metal member, and after describing the use form of the core pin and the shape of the core pin, a method for manufacturing the core pin will be described.
1 is a side cross-sectional view showing a state where the core pin is attached to a die casting die, FIG. 2 is a cross-sectional view of the core pin, and FIG. 3 is an enlarged view of a portion surrounded by an alternate long and short dash line in FIG. It is a figure which shows the manufacturing method of the core pin which concerns on this embodiment.

  FIG. 1 shows a core pin 1 fixed to a die casting die 3. The front end portion (right side in FIG. 1) 1 a side of the core pin 1 is disposed in the mold 3. A center hole is formed in the core pin 1 from the base end portion (left side in FIG. 1) along the center axis thereof, and the cooling hole 1c is a bottomed hole having a bottom portion at the tip end portion 1a. Is formed. A cooling water supply pipe (inner pipe) 5 is inserted into the cooling hole 1 c along the central axis of the core pin 1.

  Cooling water is jetted from the tip 5a of the cooling water supply pipe 5 toward the bottom of the cooling hole 1c (that is, the tip of the core pin 1) 1d (see FIG. 2). The other end of the cooling water supply pipe 5 is connected to the cooling water supply pipe 7. A cooling device main body (not shown) is provided on the upstream side of the cooling water supply pipe 7. The cooling water ejected from the tip 5a of the cooling water supply pipe 5 collides with the bottom of the cooling hole 1c, reverses the flow direction, and flows in the cooling hole 1c toward the base end 1b. When the cooling water flows in this way, the core pin 1 is cooled from the inside by receiving the heat transferred through the wall portion of the core pin 1. Cooling water that flows toward the base end 1b flows into a connecting pipe (outer pipe) 9 connected to the base end 1b of the core pin 1 and is not shown in the drawing through a cooling water return pipe 11 Led to.

  As described above, by performing the die casting manufacturing process while supplying cooling water into the core pin 1, seizure of the core pin 1 can be prevented and the shrinkage nest generated in the die cast product can be moved away from the position of the core pin 1.

FIG. 2 shows the shape of the core pin 1. Note that the shape of the core pin shown in the figure is merely an example, and the present invention is not limited to this shape.
The core pin 1 includes an outer cylinder 2 and an inner cylinder 4. The outer cylinder 2 is made of, for example, die steel (SKD61) most widely used as a die-cast metal material, and has a large-diameter portion 12 positioned on the base end portion 1b side and a tip end portion 1a side. A small-diameter tapered portion 14 having a smaller diameter than the large-diameter portion 12, and a small-diameter linear portion 16 that is located between the large-diameter portion 12 and the small-diameter tapered portion 14 and is continuously connected to the small-diameter tapered portion 14. have.

The diameter of the large diameter portion 12 is, for example, 13 mm, and the diameter of the small diameter linear portion 16 is, for example, 4.1 mm. The diameter of the small-diameter tapered portion 14 is 4.1 mm on the base end portion 1b side, and has a tapered shape that becomes tapered as it goes to the distal end. The taper angle is set to 1 °, for example. The tip of the small diameter tapered portion 14, that is, the tip 1a of the core pin 1 is processed to have a spherical shape.
The length of the outer cylinder 2 is 250 mm. The large diameter portion 12 has a length of 25 mm, the small diameter linear portion 16 has a length of 203 mm, and the small diameter tapered portion 14 has a length of 22 mm.

  The core pin 1 is formed with a central hole as a cooling hole 1c along the central axis line from the base end portion 1b to the front end portion 1a. The tip 1a side of the cooling hole 1c does not penetrate, and a bottom 1d is provided. Thus, the cooling hole 1c is a bottomed hole. Further, an outer peripheral surface (outer surface) of the inner cylinder 4, for example, a stainless steel having a thickness of 0.1 mm to 0.15 mm (more preferably 0.1 mm) is provided on the inner peripheral surface (inner surface) 2 a of the outer cylinder 2. An outer peripheral surface (outer surface) 4a of a pipe made of (for example, SUS304) is attached in close contact with a silver solder 18 (see FIG. 3B). That is, the inner peripheral surface of the outer cylinder 2 (more specifically, the inner peripheral surface of the large-diameter portion 12, the inner peripheral surface of the small-diameter tapered portion 14, and the inner peripheral surface of the small-diameter linear portion 16) 2 a is interposed via the silver solder 18. The entire inner tube 4 joined together or the whole of the connecting tube 9 excluding a female screw portion (not shown) to which the tip of the connecting tube 9 (right side in FIG. 1) is screwed is covered.

An internal thread portion (not shown) is formed on the base end portion 1 b side of the cooling hole 1 c, and the distal end of the connection pipe 9 shown in FIG. 1 is screwed to the core pin 1 by the internal thread portion. .
The wall thickness of the small-diameter linear portion 16 is 1.0 mm, and the wall thickness of the small-diameter tapered portion 14 is 0.5 mm at the thickest position on the base end portion 1b side. In addition, since the diameter is small at the tip of the small diameter taper portion 14 of the core pin 1, the thickness at this position is the thinnest.

Next, a method for manufacturing the core pin 1 will be described with reference to FIGS. 3 (a) and 3 (b).
First, a hole having an inner diameter where the difference (clearance) from the outer diameter of the stainless steel pipe serving as the inner cylinder 4 is 0.01 mm to 0.09 mm (more preferably 0.03 mm to 0.05 mm) is Drilling (machining) along the central axis of the cylinder 2.
Subsequently, a powder (particle diameter of 0.01 mm to 0.03 mm) is formed on the entire outer peripheral surface 4a of the inner cylinder 4 whose tip is drawn so that a spherical shape is formed at the tip (one end). A solution 20 (see FIG. 3A) in which silver wax, water, and flux are mixed at a ratio of 2: 2: 1 is applied, and the tip of the inner cylinder 4 is in contact with the bottom of the outer cylinder 2. The inner cylinder 4 is inserted into the hole of the outer cylinder 2 until it comes into contact. At this time, if the inner cylinder 4 is inserted into and removed from the outer cylinder 2 several times, the air layer formed between the outer peripheral surface 4a of the inner cylinder 4 and the inner peripheral surface 2a of the outer cylinder 2 is further removed. Is preferred. Further, when the tip of the inner cylinder 4 is drawn, if there is a small hole (not shown) at the tip, the outer peripheral surface 4a of the inner cylinder 4 and the outer cylinder via the hole and the cooling hole 1c. The air existing between the inner peripheral surface 2a and the inner peripheral surface 2a of the outer cylinder 2 flows out into the atmosphere, and the air layer formed between the outer peripheral surface 4a of the inner cylinder 4 and the inner peripheral surface 2a of the outer cylinder 2 is quickly And completely removed.
The melted silver wax flows into the hole formed at the tip of the inner cylinder 4, and the hole formed at the tip of the inner cylinder 4 is completely closed by this silver solder.

  Next, after putting the outer cylinder 2 in which the inner cylinder 4 is inserted into a furnace (not shown) and heating it at 1200 ° C., it is rapidly cooled in water or oil. When the outer cylinder 2 in which the inner cylinder 4 is inserted is heated at 1200 ° C., the silver wax is completely dissolved and flows evenly between the outer peripheral surface 4a of the inner cylinder 4 and the inner peripheral surface 2a of the outer cylinder 2, Or if it cools rapidly in oil, the whole outer peripheral surface 4a of the inner cylinder 4 and the whole inner peripheral surface 2a of the outer cylinder 2 will be joined in the state closely_contact | adhered by the silver solder 18 (refer FIG.3 (b)). . The melting temperature of silver wax is about 800 ° C.

According to the core pin 1 or the manufacturing method of the core pin 1 according to the present embodiment, the inner peripheral surface 2a of the outer cylinder 2 is covered with the inner cylinder 4 made of rust-resistant stainless steel, and the cooling water flowing into the cooling hole 1c is It does not come into contact with the inner peripheral surface 2 a of the cylinder 2.
Thereby, the inner peripheral surface of the core pin 1 (more specifically, the inner peripheral surface 2a of the outer cylinder 2 and the inner peripheral surface 4b of the inner cylinder 4) is oxidized, and rust is generated on the inner peripheral surface of the core pin 1. It is possible to prevent cracks and cracks from occurring in the thickness direction of the core pin 1 and to prevent the cooling water passing through the cooling hole 1c from leaking outside.
Moreover, since the inner peripheral surface 2a of the outer cylinder 2 and the outer peripheral surface 4a of the inner cylinder 4 are joined in close contact with each other through the silver solder 18, the outer cylinder 2 is efficiently cooled by the cooling water. The seizure of the core pin 1 can be prevented, and the shrinkage nest generated in the die-cast product can be moved away from the core pin 1 position.

According to the core pin 1 according to the present embodiment, the inner cylinder 4 has a very thin wall thickness of 0.1 mm to 0.15 mm. Therefore, it is necessary to increase the inner diameter and the outer diameter of the outer cylinder 2 by the thickness of the inner cylinder 4. Therefore, it is possible to prevent the diameter from expanding radially outward.
Further, the inner cylinder 4 has a very thin wall thickness of 0.1 mm to 0.15 mm, and the cooling effect by the cooling water flowing into the cooling hole 1c is substantially the same as that of a conventional thin-walled cylindrical metal member having no inner cylinder 4. Since the same level is maintained, the inner cylinder 4 is inserted into the cooling hole of the conventional thin-walled cylindrical metal member without the inner cylinder 4 to improve the conventional thin-walled cylindrical metal member. be able to.

  According to the manufacturing method of the thin-walled cylindrical metal member or the thin-walled cylindrical metal member according to the present embodiment, the bottomed hole formed in the core pin 1 serves as a cooling hole 1c for cooling by supplying cooling water. Since leakage of the cooling water that is used and passes through the cooling hole 1c is prevented, the yield of the die-cast product can be improved.

A core pin and a manufacturing method thereof according to another embodiment of the present invention will be described.
The core pin according to this embodiment is different from that of the above-described embodiment in that BAg8 (72% Ag28% Cu) is adopted as the brazing material. Other components are the same as those in the above-described embodiment.

Below, the manufacturing method of the core pin which concerns on this embodiment is demonstrated.
First, the inner diameter is such that the difference (clearance) from the outer diameter of the stainless steel pipe that becomes the inner cylinder 4 (see FIG. 2) is 0.01 mm to 0.09 mm (more preferably 0.03 mm to 0.05 mm). A hole is drilled (machined) along the central axis of the outer cylinder 2 (see FIG. 2).
Subsequently, a powder (particle diameter of 0.01 mm to 0.03 mm) is formed on the entire outer peripheral surface 4a of the inner cylinder 4 whose tip is drawn so that a spherical shape is formed at the tip (one end). Apply a solution in which BAg 8 and water are mixed at a ratio of 1: 1, and insert the inner cylinder 4 into the hole of the outer cylinder 2 until the tip of the inner cylinder 4 contacts the bottom of the outer cylinder 2. Go. At this time, if the inner cylinder 4 is inserted into and removed from the outer cylinder 2 several times, the air layer formed between the outer peripheral surface 4a of the inner cylinder 4 and the inner peripheral surface 2a of the outer cylinder 2 is further removed. Is preferred. Further, when the tip of the inner cylinder 4 is drawn, if there is a small hole (not shown) at the tip, the outer periphery of the inner cylinder 4 is passed through this hole and the cooling hole 1c (see FIG. 2). The air existing between the surface 4 a and the inner peripheral surface 2 a of the outer cylinder 2 flows out into the atmosphere, and is formed between the outer peripheral surface 4 a of the inner cylinder 4 and the inner peripheral surface 2 a of the outer cylinder 2. The air layer will be removed quickly and completely.
The melted BAg 8 flows into the hole formed at the tip of the inner cylinder 4, and the hole formed at the tip of the inner cylinder 4 is completely closed by the BAg 8.

Next, the outer cylinder 2 into which the inner cylinder 4 is inserted is put into a vacuum heat treatment furnace (not shown), heated at a pressure (degree of vacuum) of 100 Pa and 1030 ° C. for 90 minutes, and then rapidly cooled in water or oil. In the outer tube 2 to the inner tube 4 is inserted a pressure 100 Pa, 1030 ° C., is heated in 90 minutes, BAg8 is completely dissolved, the inner tube 4 an outer circumferential surface 4a and the outer cylinder 2 and the inner peripheral surface 2a When evenly flowing in between and rapidly cooling in water or oil, the entire outer peripheral surface 4a of the inner cylinder 4 and the entire inner peripheral surface 2a of the outer cylinder 2 are joined in a state of being in close contact with the BAg 8. The dissolution temperature of BAg8 at a pressure (degree of vacuum) of 100 Pa is about 1030 ° C.

  According to the core pin manufacturing method of the present embodiment, the generation of gas during vacuum heat treatment is eliminated, so that the core pin can be manufactured using a vacuum heat treatment furnace.

Further, according to the core pin or the core pin manufacturing method according to the present embodiment, the inner peripheral surface 2a of the outer cylinder 2 is covered with the inner cylinder 4 made of rust-resistant stainless steel, and the cooling water flowing into the cooling hole 1c is It does not come into contact with the inner peripheral surface 2 a of the cylinder 2.
Thereby, the inner peripheral surface of the core pin 1 (more specifically, the inner peripheral surface 2a of the outer cylinder 2 and the inner peripheral surface 4b of the inner cylinder 4) is oxidized, and rust is generated on the inner peripheral surface of the core pin 1. It is possible to prevent cracks and cracks from occurring in the thickness direction of the core pin 1 and to prevent the cooling water passing through the cooling hole 1c from leaking outside.
Further, the inner peripheral surface 2a of the outer cylinder 2 and the outer peripheral surface 4a of the inner cylinder 4 are joined in close contact with each other via the BAg 8, and the outer cylinder 2 is efficiently cooled by the cooling water. Can be prevented, and the shrinkage nest generated in the die-cast product can be kept away from the core pin position.

Furthermore, according to the core pin according to the present embodiment, the inner cylinder 4 has a very thin wall thickness of 0.1 mm to 0.15 mm, so that the inner diameter and the outer diameter of the outer cylinder 2 are increased by the thickness of the inner cylinder 4. There is no need to prevent the diameter from expanding radially outward.
Further, the inner cylinder 4 has a very thin wall thickness of 0.1 mm to 0.15 mm, and the cooling effect by the cooling water flowing into the cooling hole 1c is substantially the same as that of a conventional thin-walled cylindrical metal member having no inner cylinder 4. Since the same level is maintained, the inner cylinder 4 is inserted into the cooling hole of the conventional thin-walled cylindrical metal member without the inner cylinder 4 to improve the conventional thin-walled cylindrical metal member. be able to.

  Furthermore, according to the manufacturing method of the thin bottomed cylindrical metal member or the thin bottomed cylindrical metal member according to the present embodiment, the bottomed hole formed in the core pin is a cooling hole for cooling by supplying cooling water. Since leakage of the cooling water used as 1c and passing through the cooling hole 1c is prevented, the yield of the die-cast product can be improved.

In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably.
In the above-described embodiment, the inner cylinder 4 made of stainless steel has been described as a specific example. However, the present invention is not limited to this, and the inner cylinder 4 is made of other metal. (Copper, brass, die steel (SKD61) etc.) may be used.
Further, in the above-described embodiment, silver brazing is adopted as the brazing material, but the present invention is not limited to this, and nickel brazing or the like can also be adopted as the brazing material.

1 Core pin (thin bottomed cylindrical metal member)
DESCRIPTION OF SYMBOLS 1a Tip part 1c Cooling hole 1d Bottom part 2 Outer cylinder 2a Inner peripheral surface 4 Inner cylinder 4a Outer peripheral surface 18 Silver brazing (brazing material)
20 solutions

Claims (8)

It has an outer cylinder made of metal, and an inner cylinder made of stainless steel in which a cooling hole formed as a bottomed hole having a bottom portion at the tip is housed inside the outer cylinder . And the hole which has an internal diameter from which the difference with the outer diameter of the said inner cylinder is set to 0.01 mm-0.09 mm is a thin-walled cylindrical metal member by which it drills along the center axis line of the said outer cylinder, ,
The inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder are applied to the entire outer peripheral surface of the inner cylinder, and powdery silver wax, water, and flux are mixed at a predetermined ratio. The solution is heated at a temperature higher than the melting temperature of the silver wax and then bonded in a close contact state through the silver wax obtained by cooling in water or oil. Thin-walled cylindrical metal member with a bottom. The thin-walled cylindrical metal member according to claim 1, wherein the inner cylinder has a thickness of 0.1 mm to 0.15 mm. The thin-walled cylindrical metal member according to claim 1 or 2 , wherein the thin-walled cylindrical metal member is a core pin used in a die casting die. An outer cylinder made of metal, and an inner cylinder made of metal, which is housed in the outer cylinder and has a bottomed hole having a bottom portion at the tip, and a cooling hole formed therein. A method for producing a thin-walled cylindrical metal member comprising:
Drilling a hole having an inner diameter such that the difference from the outer diameter of the inner cylinder is 0.01 mm to 0.09 mm along the central axis of the outer cylinder,
Applying a solution in which a powdery brazing material, water, and flux are mixed at a predetermined ratio to the entire outer peripheral surface of the inner cylinder,
The inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder,
The outer cylinder in which the inner cylinder is inserted is heated at a temperature higher than the melting temperature of the brazing material, and then cooled in water or oil. Method. An outer cylinder made of metal, and an inner cylinder made of stainless steel that is housed in the outer cylinder and has a bottomed hole having a bottom portion at the tip, and a cooling hole formed therein. A method for producing a thin-walled cylindrical metal member comprising:
Drilling a hole having an inner diameter such that the difference from the outer diameter of the inner cylinder is 0.01 mm to 0.09 mm along the central axis of the outer cylinder,
Applying a solution in which powdered silver wax, water, and flux are mixed at a predetermined ratio to the entire outer peripheral surface of the inner cylinder,
The inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder,
The outer cylinder in which the inner cylinder is inserted is heated at a temperature higher than the melting temperature of the silver wax, and then cooled in water or oil. Method. An outer cylinder made of metal, and an inner cylinder made of metal, which is housed in the outer cylinder and has a bottomed hole having a bottom portion at the tip, and a cooling hole formed therein. A method for producing a thin-walled cylindrical metal member comprising:
Drilling a hole having an inner diameter such that the difference from the outer diameter of the inner cylinder is 0.01 mm to 0.09 mm along the central axis of the outer cylinder,
Applying a solution in which powdered BAg8 and water are mixed at a predetermined ratio to the entire outer peripheral surface of the inner cylinder,
The inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder,
A thin-walled bottomed cylinder characterized in that the outer cylinder into which the inner cylinder is inserted is heated in a vacuum heat treatment furnace at a temperature higher than the melting temperature of the BAg8 and then cooled in water or oil. A method for producing a metal member. An outer cylinder made of metal, and an inner cylinder made of stainless steel that is housed in the outer cylinder and has a bottomed hole having a bottom portion at the tip, and a cooling hole formed therein. A method for producing a thin-walled cylindrical metal member comprising:
Drilling a hole having an inner diameter such that the difference from the outer diameter of the inner cylinder is 0.01 mm to 0.09 mm along the central axis of the outer cylinder,
Applying a solution in which powdered BAg8 and water are mixed at a predetermined ratio to the entire outer peripheral surface of the inner cylinder,
The inner cylinder is inserted into the hole of the outer cylinder until the tip of the inner cylinder contacts the bottom of the outer cylinder,
A thin-walled bottomed cylinder characterized in that the outer cylinder into which the inner cylinder is inserted is heated in a vacuum heat treatment furnace at a temperature higher than the melting temperature of the BAg8 and then cooled in water or oil. A method for producing a metal member. The method for producing a thin-walled cylindrical metal member according to any one of claims 4 to 7 , wherein the thin-walled cylindrical metal member is a core pin used in a die casting die.

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