JP4500697B2 - Manufacturing apparatus and manufacturing method of tube in solenoid - Google Patents

Description

  The present invention relates to a tube manufacturing apparatus and method for a solenoid or solenoid valve.

  Conventionally, as shown in FIG. 7, a tube 73 comprising a magnetic part 71 and a non-magnetic part 72 is used as a component such as a solenoid or a solenoid valve. The solenoid using the tube 73 is used in such a manner that a plunger 74 (movable iron core) slidable along the inner peripheral surface of the tube 73 is disposed and a coil 75 is disposed on the outer peripheral portion of the tube 73.

  The operation of this solenoid will be described. By energizing the coil 75, a magnetic flux is generated around the coil 75, and the magnetic flux flows through a magnetic circuit composed of the magnetic part 71 of the tube 73 and the plunger 74. The plunger 74 moves the shaft 76 integral with the plunger 74 against the return spring 77 by a solenoid thrust generated in the coil 75.

  Here, if the entire tube 73 is made of a magnetic material, the generated magnetic flux flows through the tube 73 and hardly flows into the plunger 74, so that the solenoid thrust generated in the coil 75 is difficult to act on the plunger 74. For this reason, it is necessary to configure a part of the tube 73 with a nonmagnetic material so that the magnetic flux can easily flow through the plunger 74.

  As a method of manufacturing a tube composed of a magnetic part and a non-magnetic part, Patent Document 1 discloses that a core, a thin part, and a valve housing part are integrally formed of a magnetic material, and carburizing is performed on the thin part. Describes an invention in which the thin portion is modified to be non-magnetic. However, the method described in Patent Document 1 is limited to the case where the magnetic part and the nonmagnetic part are made of the same material.

  As a method for manufacturing a tube when the magnetic part and the nonmagnetic part are made of different materials, Patent Document 2 discloses an invention in which a core that is a magnetic part and an intermediate part that is a nonmagnetic part are joined by welding. ing. However, in the method using welding, it is necessary to select a material that is less likely to cause defects such as weld cracks. For this purpose, it is necessary to use a material such as special steel in which the content of impurity elements that impede weldability is limited, which is not suitable for mass production.

  Therefore, as another method, there is a method using welding that uses a difference in melting points of different materials. As shown in FIG. 8A, a tube body 81 made of a magnetic material and having a recess 84 in a part of the outer periphery and a nonmagnetic material 82 having a melting point lower than that of the magnetic material are accommodated in a mold 83. The mold 83 is heated in the heating furnace to the melting point of the nonmagnetic material 82 or higher. According to this method, the melted nonmagnetic material 82 flows into the concave portion 84 of the tube body 81, and as shown in FIG. 8B, a tube 87 composed of the tube body 81 and the welded nonmagnetic portion 85 is obtained. be able to.

JP 2003-278622 A Japanese Patent Application Laid-Open No. 11-200979

However, in the tube manufacturing method using the conventional welding described above, the solidification form after the nonmagnetic material 82 is melted is not controlled, so the melted nonmagnetic material 82 is in contact with the die 83 on the outer peripheral side. Coagulation starts from the inside, and the inner periphery side is the final coagulation position. Thus, since solidification starts from the outer peripheral side first, solidification shrinkage occurs on the outer peripheral side, and a shrinkage nest 86 is generated on the inner peripheral side.
As described above, in the conventional tube manufacturing method using welding, the occurrence of shrinkage cavities on the inner peripheral side of the nonmagnetic portion is inevitable. For this reason, in the tube complete product 88 after the tube 87 is taken out from the mold 83 and the outer peripheral portion is cut (see FIG. 8C), the shrinkage nest 86 remains in the nonmagnetic portion 85, and the tube complete product 88 remains. Led to a decrease in strength. In addition, when oil is used, it also causes oil leakage.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a tube manufacturing apparatus and a manufacturing method for a solenoid in which there is little shrinkage in the nonmagnetic portion.

An apparatus for manufacturing a tube in a solenoid according to the present invention includes: a mold having a tube body that is a magnetic material; a housing portion that houses a weld metal that is a nonmagnetic material; and a hole portion that penetrates the housing portion; A cooling jig to be inserted, and the tube main body is formed in the axial direction of the tube main body and communicated with the hole portion, and is formed on the outer periphery so as to face the hole portion, and the weld metal is welded. The welding metal has a melting point lower than the melting point of the material of the tube main body, the cooling jig is a rod-shaped member, and a heat absorbing part fitted into the hole of the tube main body, A heat radiating portion protruding from the mold, the heat absorbing portion of the rod-shaped member has a relief portion having a small outer diameter, and the heat absorbing portion is located away from the bottom portion of the recess. So that the front of the tube body Fitted into the hole portion, characterized in that removing heat of the weld metal was dissolved in the recess of the tube body from the inner circumferential side.

In addition, the method of manufacturing a tube in the solenoid according to the present invention includes a tube body that is a magnetic material and a weld metal that is a non-magnetic material in a housing portion in a mold, and a hole that is formed in the mold and penetrates the housing portion. Fitting a heat absorption part of a cooling jig to a hole part formed in the axial direction of the tube body and the hole part and communicating with the hole part, and installing the mold in a heating furnace and attaching the mold to the weld metal Heating above the melting point, allowing the weld metal to flow into a recess formed on the outer periphery of the tube body and facing the hole, and melting in the recess of the tube body by the heat absorbing part of the cooling jig the had ablative the weld metal of the heat from the inner circumferential side, and a step of radiating heat by contacting the cooling gas to the heat radiating portion of the cooling jig protruding from the mold, of the rod-shaped member The endothermic part is It has an outer diameter smaller relief portion, the heat absorbing unit is characterized in that said relief portion is fitted into the hole of the tube body so as to be positioned away from the bottom of the recess.

  The weld metal that has melted and flowed into the recess is deprived of heat from the inner peripheral side by the cooling jig fitted into the hole of the tube body, and the heat is released to the outside. As a result, the weld metal can be solidified from the inner peripheral side close to the cooling jig, and the final solidification position can be located on the outer peripheral side far from the cooling jig. Therefore, according to the present invention, even when a shrinkage nest is generated, the shrinkage nest can be scraped off by cutting, so that the non-magnetic portion in the finished tube product has a structure with a small shrinkage nest.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
With reference to FIGS. 1-3, the tube manufacturing apparatus 100 which is Embodiment 1 of this invention is demonstrated. FIG. 1 is a cross-sectional view showing the tube manufacturing apparatus 100 before the weld metal is melted, FIG. 2 is a cross-sectional view showing the tube manufacturing apparatus 100 after the weld metal is melted, and FIG. 3 is a completed tube. It is sectional drawing which shows goods.

  The tube manufacturing apparatus 100 is a tube manufacturing apparatus in a solenoid for welding a weld metal 2 that is a nonmagnetic material to a tube body 1 that is a magnetic material, and a mold 3 that houses the tube body 1 and the weld metal 2. The rod-like member 4 is provided as a cooling jig for removing heat of the weld metal 2 from the inner peripheral side and dissipating the heat to the outside.

  The tube body 1 has a substantially cylindrical shape, and includes an annular recess 1 a formed on the outer periphery and a stepped hole 1 b formed in the axial direction of the tube body 1. The concave portion 1a is a groove into which the weld metal 2 is melted and flows, and the groove cross section is formed in a tapered shape toward the hole portion 1b. The bottom 1c of the recess 1a has a structure facing the hole 1b via the thin portion 1d. The hole 1b is for fitting a cooling jig, and includes a small diameter part 1f that contacts a large diameter part 1e that does not contact the cooling jig. The hole 1b extends at least to a position deeper than the recess 1a, but may be a hole penetrating the tube body 1.

  The welding metal 2 has a melting point lower than the melting point of the material of the tube body 1, and is formed, for example, in a hollow cylindrical shape and disposed on the outer periphery of the tube body 1. The shape of the weld metal 2 is not particularly limited, and a plurality of cylindrical ones may be arranged on the outer periphery of the tube body 1 in an annular shape.

  The mold 3 includes a lower mold 3a and an upper mold 3b, and has an opening at the contact surface 9 of each other. The lower mold 3a is formed with a hole 5a that opens in the contact surface 9, and a step 5b on which the weld metal 2 is placed is formed in the hole 5a. The upper mold 3b is formed with a hole 6 that opens coaxially with the hole 5a in the contact surface 9, and on the opposite side of the contact surface 9 is a hole that is a through hole through which the rod-like member 4 is inserted. Part 7 is formed. In a state in which the lower mold 3a and the upper mold 3b are brought into contact with each other at the contact surface 9, a housing portion that houses the tube main body 1 and the weld metal 2 through the hole 5a in the lower mold 3a and the hole 6 in the upper mold 3b. 8 is configured, and the hole 7 passes through the accommodating portion 8.

  In a state where the tube body 1 is housed in the housing portion 8, the hole portion 7 of the upper mold 3 b and the hole portion 1 b of the tube body 1 are in coaxial communication. In this state, the rod-like member 4 is inserted through the hole 7 of the upper mold 3b and is fitted into the hole 1b of the tube main body 1 and arranged. As described above, the rod-shaped member 4 includes the heat absorbing portion 4 a that comes into contact with the small diameter portion 1 f on the distal end side of the hole portion 1 b of the tube main body 1 and the heat radiating portion 4 b that protrudes from the mold 3. Since the material of the rod-shaped member 4 is for cooling the weld metal 2, it is desirable to use a metal having a high thermal conductivity such as steel, stainless steel, or nickel alloy.

  The tube body 1 is made of a steel material. The weld metal 2 is suitably copper or a copper alloy having a melting point lower than that of steel, and specifically brass is used. However, the combination of the material of the tube main body 1 and the weld metal 2 is not particularly limited as long as the melting point of the weld metal 2 is lower than the melting point of the tube main body 1. The mold 3 is made of carbon.

Below, the procedure of the manufacturing method of the tube using the tube manufacturing apparatus 100 is demonstrated.
(1) As shown in FIG. 1, the tube body 1 is housed in the housing portion 8 of the mold 3, and the weld metal 2 is placed on the step portion 5 b in the housing portion 8 so as to surround the outer periphery of the tube body 1. .
(2) The rod-like member 4 is inserted into the hole 7 of the mold 3, and the heat absorbing part 4 a is fitted into the small diameter part 1 f on the distal end side of the hole 1 b of the tube body 1.
(3) The mold 3 is placed in the heating furnace with the surface opposite to the contact surface 9 of the lower mold 3a as the bottom surface. A reducing gas such as nitrogen gas for preventing oxidation circulates in the heating furnace, and the heat radiating portion 4b of the rod-like member 4 is exposed to the reducing gas.
(4) The mold 3 is heated to a temperature not lower than the melting point of the weld metal 2 and not higher than the melting point of the tube body 1 by radiant heat in the heating furnace. Thereby, as shown in FIG. 2, the welding metal 2 melt | dissolves and flows into the recessed part 1a of the tube main body 1. FIG. Further, the heat absorbing portion 4 a of the rod-like member 4 is thermally expanded and is in close contact with the tube body 1.
(5) The bottom 1c of the recess 1a has a structure facing the small-diameter portion 1f on the distal end side of the hole 1b through the thin portion 1d. Therefore, the rod-shaped member 4 exposed to the reducing gas flowing in the heating furnace takes the heat of the weld metal 2 flowing into the concave portion 1a from the inner peripheral side through the heat absorbing portion 4a in contact with the small diameter portion 1f of the tube body 1, The heat is dissipated by the heat dissipating part 4b. As a result, the melted weld metal 2 starts to solidify from the inner peripheral side, that is, the bottom 1c, and the outer peripheral side, that is, the portion close to the mold 3 becomes the final solidification position. As described above, the rod-like member 4 is configured to contact the hole 1 of the tube body 1 only with the small-diameter portion 1f opposed to the bottom portion 1c and not to contact the large-diameter portion 1e. The heat of the deposited metal 2 can be efficiently removed without taking away heat.
(Depending on the action of the rod-shaped member 4, if the melted weld metal 2 does not completely solidify, the temperature in the heating furnace is lowered to a temperature below the melting point of the weld metal 2 or the mold 3 is removed from the heat source of the heating furnace. You may make it reduce the temperature of the welding metal 2 to the temperature below melting | fusing point by keeping away with a belt conveyor etc. By doing so, solidification of the melted welding metal 2 is transmitted from an inner peripheral side to an outer peripheral side. It will be easier.)
(6) After the mold 3 is taken out of the heating furnace and cooled to room temperature, the outer periphery of the tube body 1 in which the shrinkage nest 10 is interposed is scraped off by cutting, so that no shrinkage nest is present as shown in FIG. A tube complete product 101 can be obtained.

  As described above, the weld metal 2 that has melted and flowed into the recess 1 a of the tube body 1 starts to solidify from the inner peripheral side close to the rod-like member 4 by the action of the rod-like member 4. Final coagulation will occur. Therefore, according to the present invention, even when a shrinkage nest is generated, the shrinkage nest can be positioned on the outer periphery side of the tube, so that the portion can be scraped off by cutting. Thereby, the structure of the non-magnetic part in the tube finished product can be made healthy without shrinkage.

(Embodiment 2)
With reference to FIG. 4, the tube manufacturing apparatus 200 which is Embodiment 2 of this invention is demonstrated. 4A is a cross-sectional view showing the tube manufacturing apparatus 200, and FIG. 4B is a partially enlarged view. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1 mentioned above.

  The difference between the tube manufacturing apparatus 200 and the tube manufacturing apparatus 100 is that the heat absorbing portion 4a of the rod-shaped member 4 as a cooling jig has a relief portion 12. The outer diameter of the escape portion 12 is configured to be smaller than the outer diameter of the heat absorbing portion 4a. In addition, the escape portion 12 is configured to be located away from the bottom portion 1c of the recess 1a in a state where the heat absorption portion 4a is fitted to the small diameter portion 1f of the hole portion 1b of the tube body 1.

  Since the escape portion 12 is not in contact with the tube body 1 by providing the escape portion 12 in the heat absorption portion 4a, the heat absorption portion 4a in contact with the tube body 1 can efficiently take away the heat of the melted weld metal 2. . Thereby, solidification of the melted weld metal 2 can be surely started from the bottom 1c facing the heat absorbing part 4a, that is, the part closest to the heat absorbing part 4a. Thus, according to the tube manufacturing apparatus 200, the generation of the shrinkage nest can be positioned more on the tube outer peripheral side.

  In the second embodiment, an embodiment in which one escape portion 12 is provided in the heat absorbing portion 4a is shown, but as another configuration, two escape portions are provided in the heat absorbing portion 4a, and the bottom portion 1c of the recess 1a is released. You may comprise the rod-shaped member 4 so as to oppose the heat absorption part 4a between the parts 12. FIG. If comprised in this way, solidification of the melt | dissolved weld metal will start reliably from the bottom part 1c.

(Embodiment 3)
With reference to FIG. 5, the tube manufacturing apparatus 300 which is Embodiment 3 of this invention is demonstrated. FIG. 5 is a cross-sectional view showing the tube manufacturing apparatus 300. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1 mentioned above.

  The difference between the tube manufacturing apparatus 300 and the tube manufacturing apparatus 100 is that a heat retaining case 16 having a through hole 15 on the outside of the mold 3 is provided. The mold 3 is arranged in a state where the heat radiating portion 4 b in the rod-like member 4 protrudes from the through hole 15.

  The heat retaining case 16 is made of steel and, as shown in FIG. 5A, accommodates the mold 3 to prevent the reducing gas circulating in the heating furnace from directly contacting the mold 3. The outer peripheral temperature of the mold 3 can be kept high. That is, the heat retaining case 16 has a function of keeping the temperature inside the heat retaining case 16.

  Thereby, the outer peripheral side of the melted weld metal 2 becomes more difficult to be cooled as compared with the case where the heat retaining case 16 is not used. Therefore, solidification of the melted weld metal easily proceeds from the inner peripheral side to the outer peripheral side, and the final solidification position can be surely set to the outer peripheral side.

  Further, as shown in FIG. 5B, since the heat insulating gas layer 17 is formed between the heat insulating cases 16a and 16b by providing two or more heat insulating cases 16, the heat insulating effect of the heat insulating case 16 is achieved. Is more effective.

(Embodiment 4)
With reference to FIG. 6, the tube manufacturing apparatus 400 which is Embodiment 4 of this invention is demonstrated. FIG. 6 is a cross-sectional view showing the tube manufacturing apparatus 400. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1 mentioned above.

  The difference between the tube manufacturing apparatus 400 and the tube manufacturing apparatus 100 is that the cooling jig is a funnel 21 for introducing the cooling reducing gas into the hole 1b.

  The funnel 21 is made of steel and includes a head portion 22 and a pipe portion 23 as shown in FIG. 6, and an opening portion 24 that is an inlet for reducing gas is formed in the head portion 22. A nozzle 25 is formed as an outlet for reducing gas. On the opposite side of the head 22 from the surface having the opening 24, there is a contact surface 26 that contacts the surface of the mold 3 having the hole 7. Further, the tube portion 23 is inserted into the hole portion 1 b of the tube body 1, and the tip of the nozzle 25 of the funnel 21 is configured to be positioned in the hole portion 1 b of the tube body 1.

A method for manufacturing a tube when the tube manufacturing apparatus 400 is used will be described.
In the tube manufacturing apparatus 400, the funnel 21 for introducing the reducing gas for cooling into the hole 1b of the tube main body 1 is used instead of the rod-like member 4 in the first embodiment. The procedure until the weld metal 2 is dissolved is the same as the procedure shown in the first embodiment, and the method for solidifying the weld metal 2 flowing into the concave portion 1a of the tube body 1 is as follows.
By introducing the reducing gas into the hole 1b of the tube body 1 by forcibly injecting the reducing gas into the opening 24 of the funnel 21 with the weld metal 2 flowing into the recess 1a of the tube body 1, the recess The heat of the weld metal 2 flowing into 1a is taken away. As a result, the melted weld metal 2 starts to solidify from the inner peripheral side close to the hole 1b. That is, the tube manufacturing apparatus 400 forcibly gas-cools the weld metal 2 using the funnel 21.

  As described above, the melted weld metal 2 starts to solidify from the inner peripheral side close to the hole 1b by the reducing gas introduced from the funnel 21, and thus finally solidifies on the outer peripheral side far from the hole 1b. . Therefore, according to the present invention, even when a shrinkage nest is generated, the shrinkage nest can be positioned on the outer periphery side of the tube, so that the portion can be scraped off by cutting. As a result, the structure of the non-magnetic part in the tube finished product can be sound without shrinkage.

  Further, as another configuration of the funnel 21, the tube portion 23 is formed so that a gap exists between the tube portion 23 and the inner peripheral surface of the hole portion 1b even when the tube portion 23 is thermally expanded. A plurality of reducing gas discharge grooves 27 may be provided radially on the contact surface 26 of 21.

  By configuring the funnel 21 in this manner, the reducing gas introduced into the hole 1b of the tube body 1 passes through the gap between the tube 23 and the inner peripheral surface of the hole 1b and is provided on the contact surface 26. It is discharged from the groove 27. Thus, since the reducing gas introduced into the hole 1b flows without staying, the inner peripheral surface of the hole 1b in the tube main body 1 can be efficiently cooled. The solidification easily proceeds from the inner peripheral side to the outer peripheral side, and the final solidification position can be surely set to the outer peripheral side. In addition, the shape of the groove | channel 27 provided in the contact surface 26 should just discharge | emit the reducing gas introduced into the hole 1b outside.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The tube manufacturing apparatus and manufacturing method of the present invention can be used for manufacturing a tube used for a solenoid or a solenoid valve.

It is sectional drawing which shows the tube manufacturing apparatus 100 before the welding metal in Embodiment 1 of this invention melt | dissolves. It is sectional drawing which shows the tube manufacturing apparatus 100 after the welding metal in Embodiment 1 of this invention melt | dissolved. It is sectional drawing which shows the tube finished product in Embodiment 1 of this invention. It is sectional drawing which shows the tube manufacturing apparatus 200 in Embodiment 2 of this invention. It is sectional drawing which shows the tube manufacturing apparatus 300 in Embodiment 3 of this invention. It is sectional drawing which shows the tube manufacturing apparatus 400 in Embodiment 4 of this invention. It is sectional drawing which shows a general solenoid. (A) It is sectional drawing which shows the tube by which the nonmagnetic part was welded to the magnetic part. (B) It is sectional drawing which shows a tube finished product.

Explanation of symbols

100, 200, 300, 400 Tube manufacturing apparatus 101, 88 Tube finished product 1, 81 Tube body 1a, 84 Recess 1b Hole 1c Bottom 1d Thin portion 1e Large diameter portion 1f Small diameter portion 2 Weld metal 3, 83 Type 4 Rod-shaped member 4a Heat absorbing portion 4b Heat radiating portion 7 Hole portion 8 Receiving portion 9 Contact surface 10, 86 Shrinkage 12 Relief portion 15 Through hole 16 Thermal insulation case 17 Heat insulating gas layer 21 Funnel 22 Head portion 23 Pipe portion 24 Opening portion 25 Nozzle 26 Contact surface 27 Groove 82 Nonmagnetic material 85 Nonmagnetic part

Claims (6)

A mold having a tube body that is a magnetic material and a housing portion that houses a weld metal that is a non-magnetic material, and a hole that penetrates the housing portion;
A cooling jig for inserting the hole,
The tube body has a hole portion formed in the axial direction of the tube body and communicating with the hole portion, and a recess portion formed on the outer periphery so as to face the hole portion and welded with the weld metal.
The welding metal has a melting point lower than the melting point of the tube body material,
The cooling jig is a rod-shaped member, and has a heat absorption part that fits into the hole of the tube body, and a heat dissipation part that protrudes from the mold,
The heat absorbing part of the rod-shaped member has a relief part with a small outer diameter,
The heat absorbing portion is fitted into the hole portion of the tube main body so that the escape portion is located away from the bottom of the concave portion, and the heat of the weld metal melted in the concave portion of the tube main body is on the inner peripheral side. An apparatus for manufacturing a tube in a solenoid, characterized in that it is deprived of. The bottom part of the said recessed part faces the two said escape parts formed in the said heat absorption part in the state which the said heat absorption part fitted in the said hole part of the said tube main body, The Claim 1 characterized by the above-mentioned. Manufacturing equipment for tubes in solenoids.   The said hole part consists of a small diameter part which contacts the large diameter part which does not contact the said jig | tool for cooling, The manufacturing apparatus of the tube in the solenoid of Claim 1 or 2 characterized by the above-mentioned. Comprising a heat insulating case having a through hole, the mold is housed inside the insulation casing, to any one of claims 1 3, wherein the heat radiating portion of the rod-shaped member is characterized in that projecting from the through hole An apparatus for manufacturing a tube in the solenoid described above. Apparatus for producing a tube in the solenoid according to claim 4, characterized by providing a heat insulating gas layer between insulation casing by providing overlapping said insulation case two or more. A tube body that is a magnetic material and a weld metal that is a non-magnetic material are accommodated in a housing portion in a mold, and a hole portion that is formed in the mold and passes through the housing portion, and is formed in the axial direction of the tube body. Fitting the heat absorption part of the cooling jig into the hole communicating with
Placing the mold in a heating furnace, heating the mold to a melting point of the weld metal or higher, and allowing the weld metal to flow into a recess formed on the outer periphery of the tube body and facing the hole;
There deprive the weld metal of the heat dissolved in the recess of the tube body by the heat absorption part of the cooling jig from the inner peripheral side, the cooling gas to the heat radiating portion of the cooling jig protruding from the mold and a step of radiating heat by contacting,
The heat absorbing part of the rod-shaped member has a relief part with a small outer diameter,
The method of manufacturing a tube in a solenoid , wherein the heat absorbing portion is fitted into the hole portion of the tube main body so that the escape portion is located away from a bottom portion of the concave portion .

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