JP3788777B2 - Metal member joining device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a metal member joining apparatus for joining an annular valve seat member to a supply / exhaust port portion of a cylinder head in an automobile engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a technique has been proposed in which an annular valve seat member coated with a brazing material is embedded in a supply / exhaust port portion of a cylinder head in an automobile engine by using heat generated by electric resistance (for example, Patent Document 1). reference).
[0003]
Further, a configuration has been proposed in which the inner peripheral portion of the annular valve seat member is held by expanding the diameter of a collet chuck provided at the center of the electrode portion (see, for example, Patent Document 2).
[0004]
[Patent Document 1]
JP 2000-263243 A (FIG. 6)
[Patent Document 2]
JP 2002-153974 A (FIG. 2)
Further, as shown in FIG. 6, the central portion 29 ′ of the electrode portion 19 ′ is inserted into the inner peripheral portion 20 b of the annular valve seat member 20, and is urged by a spring in the outer diameter direction from the outer peripheral portion of the central portion 29 ′. A configuration may be conceived in which the steel ball 19a ′ is held in contact therewith.
[0005]
[Problems to be solved by the invention]
However, the valve seat member holding mechanism using the collet chuck or steel ball has the following problems. That is,
(1) Burrs generated during joining enter the movable part of the collet chuck or steel ball and cannot be held.
[0006]
(2) Durability sufficient to withstand the pressing force and heat generation at the time of joining cannot be ensured, resulting in a decrease in mass productivity.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a metal member joining apparatus that can realize the holding and positioning of a valve seat member with a simple configuration, and can improve durability and mass productivity. It is.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, the metal member joining apparatus according to the present invention converts the first metal member into a second metal member having a melting point lower than that of the first metal member by energization and pressing by the electrode portion. An apparatus for joining metal members to be joined, wherein the electrode portion includes an electrode holder and an electrode tip attached to a tip portion of the electrode holder, and the electrode tip has a thin portion that abuts on the first metal member; A positioning portion for positioning the first metal member with respect to the electrode portion is provided, and holding means for attracting and holding the first metal member by magnetic force is provided inside the electrode holder facing the thin portion.
[0009]
Preferably, in the above apparatus, the first metal member is an annular valve seat member, the thin portion is formed in an annular shape corresponding to the first metal member, and the positioning portion is an inner portion of the first metal member. It is formed so as to protrude through the peripheral portion.
[0010]
Preferably, in the above apparatus, a coolant supply means for circulating a coolant in the electrode holder and the electrode tip is provided.
[0011]
Preferably, in the above apparatus, the electrode tip is detachably provided on the electrode holder.
[0012]
Preferably, in the above apparatus, the coolant supply means has a through-hole penetrating the tip portion of the electrode tip.
[0013]
【The invention's effect】
As described above, according to the invention of claim 1, the electrode chip is provided with the thin portion that contacts the first metal member and the positioning portion that positions the first metal member with respect to the electrode portion, By providing a holding means for attracting and holding the first metal member by magnetic force inside the electrode holder facing the thin wall portion, the holding and positioning of the first metal member can be realized with a simple configuration, and durability and mass productivity can be achieved. Can also be increased.
[0014]
According to the invention of claim 2, the first metal member is an annular valve seat member, the thin portion is formed in an annular shape corresponding to the first metal member, and the positioning portion is formed on the inner peripheral portion of the first metal member. By projecting so as to be inserted, the valve seat member can be held and positioned with a simple configuration, and durability and mass productivity can be improved.
[0015]
According to the invention of claim 3, by providing the coolant supply means for circulating the coolant inside the electrode holder and the electrode tip, the cooling performance of the electrode tip is enhanced and the durability of the electrode portion is enhanced. Can do.
[0016]
According to the invention of claim 4, since the electrode tip is detachably provided on the electrode holder, it is not necessary to exchange the holding means when exchanging the electrode tip, and the mass production cost can be greatly reduced. it can.
[0017]
According to the fifth aspect of the present invention, the coolant supply means has the through-hole penetrating the tip of the electrode tip, so that the fluidity of the coolant is increased and the coolability of the electrode tip can be improved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0019]
The embodiment described below is an example as means for realizing the present invention, and the present invention can be applied to a modified or modified embodiment described below without departing from the spirit of the present invention.
[0020]
[Metal member joining device]
FIG. 1 is a diagram illustrating an overall configuration of a metal member bonding apparatus (hereinafter referred to as a bonding apparatus) according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a configuration of an electrode portion of the bonding apparatus of FIG. FIG. 3 is a cross-sectional view showing the positional relationship between the valve seat member and the cylinder head joined by the joining device of FIG.
[0021]
In FIG. 1, a joining apparatus 1 includes a transformer 12 as a transformer provided on a base 11, and a stage 13 provided on a base 11 on the side of the transformer 12 so as to be movable in a two-dimensional direction. The cylinder head 15 is disposed inside the water tank 14 filled with the cooling liquid 33 held on the stage 13.
[0022]
Further, an electrical resistance welding unit 16 electrically connected to the transformer 12 is provided on the side of the transformer 12 and above the cylinder head 15. An electrode portion 19 is attached via the platen 18.
[0023]
As shown in FIG. 2, an annular valve seat member 20 is detachably held at the lower end portion of the electrode portion 19. The cylinder head 15 is made of, for example, an aluminum alloy that is a conductive material, and the valve seat member is a sintered material made of, for example, an iron-based material that is a conductive material.
[0024]
As shown in FIG. 3, the valve seat member 20 has an upper end surface 20a and an inner peripheral portion 20b that are non-joining end surfaces, and an outer peripheral portion on which two tapered portions 20c and 20d are formed as joining end surfaces. In the cooling liquid 33 in the water tank 14, the taper portion 20c is brought into contact with the opening edge portion 15b of the port portion 15a of the cylinder head 15 by being pressed by the electrode portion 19, and the heat generation is concentrated by energization to make the cylinder head The material is pushed in while plastically flowing.
[0025]
As shown in FIG. 2, the electrode portion 19 is detachably attached to the lower portion of the platen 18 by a bolt 21 a and the like, and the lower end portion of the electrode tip holder 21 is detachably attached by a convex screw. And the cylindrical curtain member 23 provided on the outer peripheral surface of the electrode tip holder 21.
[0026]
The electrode tip holder 21 is made of a conductive material such as chrome copper, and the electrode tip 22 is also made of a conductive material such as chrome. The curtain member 23 forms a curtain passage 23 a that opens downward between the outer periphery of the electrode tip holder 21.
[0027]
Inside the electrode tip holder 21, a coolant (plant water) introduced from the outside is circulated in the axial direction of the holder, and cooled from the outer peripheral surface of the electrode tip holder 21 to the coolant passage 24. An introduction passage 25 for introducing the liquid and a branch passage 26 branched from the coolant passage 24 and communicating with the curtain passage 23a between the outer peripheral surface of the electrode tip holder 21 and the curtain member 23 are formed. .
[0028]
In addition, an in-chip passage 27 that communicates with the coolant passage 24 while being attached to the electrode tip holder 21 is also formed inside the electrode tip 22. Further, the in-chip passage 27 forms a through hole 27 a that penetrates the tip of the protruding portion of the electrode tip 22. Thus, by providing the through hole 27a, the fluidity of the cooling liquid is increased, and the cooling performance of the electrode tip 22 can be enhanced.
[0029]
A coolant of about 5 atm is introduced into the coolant passage 24 and the in-chip passage 27 from the introduction passage 25 to cool the electrode tip 22. Further, the coolant flowing into the curtain passage 23 a from the branch passage 26 is discharged in the form of a curtain to the outer periphery of the electrode tip 22, and in the coolant 33 from the joint interface to the non-joint end face of the valve seat member 20 or the outer periphery of the electrode tip 22. It is possible to suppress the growth of the burr B1 made of the brazing material and the cylinder head material discharged to the portion, to suppress the burr B1 from adhering to the electrode tip 22, and to improve the electrode life.
[0030]
The electrode chip 22 has a thin portion 28 that comes into contact with an upper end surface 20 a that is a non-joint end surface of the valve seat member 20, and the thin portion 28 is in contact with the upper end surface 20 a of the valve seat member 20. And a positioning portion 29 that fits on the non-joining end face side of the inner peripheral portion 20b without a gap and is tapered toward the joining end face side to form a gap with the inner peripheral portion 20b. .
[0031]
The positioning portion 29 is formed so as to protrude downward from the joining end surface side (lower surface side) of the valve seat member 20, and is fitted to the non-joining end surface side of the inner peripheral portion 20b of the valve seat member 20 without a gap. The valve seat member 20 is positioned with respect to the electrode chip 22.
[0032]
In addition, a heat-resistant samarium cobalt magnet 31 (hereinafter referred to as a magnet 31) is provided at the tip of the electrode tip holder 21 facing the thin portion 28 via a seal member 30. The sheet member 20 is sucked and held on the lower surface of the thin portion 28. The seal member 30 is a rust-proof seal for joining in the coolant 33 and is fixed to the electrode chip holder 22 with an adhesive.
[0033]
Since the electrode chip 22 is detachable from the electrode chip holder 21, it is not necessary to replace the magnet 31 when replacing the electrode chip, and the mass production cost can be greatly reduced.
[0034]
The magnet 31 is attached to the inside of the electrode tip holder 22 at least three places (for example, at intervals of 120 °), and the valve seat member 20 is prevented from falling off from the electrode tip 22 before joining, and can be securely held.
[0035]
Further, by using the heat-resistant magnet 31, it is possible to maintain a magnetic force sufficient to hold the sheet member 20 against heat generation and a strong magnetic field that are repeatedly generated at the time of joining.
[0036]
FIG. 4 shows the relationship between the number of bonding sheets (number of times of bonding) using the electrode portion of this embodiment and the magnetic force, and it can be confirmed that there is no deterioration of the magnetic force even when the number of times of bonding is about 2800 times. It turns out that it is suitable for. In addition, the magnetic force shown in FIG. 4 is represented by the average value of three places.
[0037]
The thin portion 28 is formed in an annular shape corresponding to the annular valve seat member 20, and is set to a thickness of about 2 mm so that the magnetic force of the magnet 31 acts on the valve seat member 20. The magnetic force sufficient to hold the valve seat member 20 can be maintained without being deformed by the pressure (about 3.0 tons).
[0038]
FIG. 5 is a diagram illustrating a joining process between the cylinder head and the valve seat member.
[0039]
The joining conditions in this joining process are, for example, a pressing force of 3.0 tons, a current of 90 kA, and an energization time of 0.3 to 0.5 seconds. In the joining process, first, the electrode tip 22 of the electrode portion 19 is held. The valve seat member 20 is moved to the port opening edge 15b of the cylinder head 15, and the valve seat 20 previously coated with the brazing material is brought into contact as shown in FIG.
[0040]
Next, as shown in FIG. 5B, the valve seat member 20 is pressed against the port opening edge 15b by the contact portion 28 of the electrode tip 22 and energized at the same time. Since there is an electrical resistance at the joint surface between the port opening edge 15b of the cylinder head 15 and the tapered portion 20c of the valve seat member 20, the joint surface is heated by pressing and (pulse) energization by the electrode tip 22. The And by continuing this pressurization and heating, the material of the port opening edge 15b of the cylinder head 15 plastically flows, so that the valve seat member 20 passes through the state of FIG. ) And is buried in the port portion 15a of the cylinder head 15 and melt diffusion bonded.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a metal member joining apparatus according to an embodiment of the present invention.
2 is a cross-sectional view showing a configuration of an electrode portion of the bonding apparatus of FIG.
3 is a cross-sectional view showing a positional relationship between a valve seat member and a cylinder head that are joined by the joining device of FIG. 1;
FIG. 4 is a diagram showing the relationship between the number of bonding sheets (number of bondings) using the electrode portion of the present embodiment and the magnetic force.
FIG. 5 is a diagram illustrating a joining process between a cylinder head and a valve seat member.
FIG. 6 is a diagram showing a configuration of an electrode portion that holds a conventional valve seat member.
[Explanation of symbols]
12 Transformer 15 Cylinder head 18 Platen 19 Electrode portion 20 Valve seat member 21 Electrode tip holder 22 Electrode tip 23 Curtain member 23a Curtain passage 24 Cooling fluid passage 25 Introduction passage 26 Branch passage 27a Through hole 28 Thin portion 29 Positioning portion 30 Sealing member 31 Magnet B1 burr

Claims (5)

A metal member joining apparatus for joining a first metal member to a second metal member having a melting point lower than that of the first metal member by energization and pressing by an electrode part,
The electrode part comprises an electrode holder and an electrode tip attached to the tip of the electrode holder,
The electrode tip is provided with a thin portion that contacts the first metal member, and a positioning portion that positions the first metal member with respect to the electrode portion,
An apparatus for joining metal members, wherein a holding means for attracting and holding the first metal member by magnetic force is provided inside the electrode holder facing the thin-walled portion.   The first metal member is an annular valve seat member, the thin portion is formed in an annular shape corresponding to the first metal member, and the positioning portion is inserted through an inner peripheral portion of the first metal member. The metal member bonding apparatus according to claim 1, wherein the metal member bonding apparatus is formed so as to protrude. The metal member joining apparatus according to claim 1, wherein a cooling liquid supply means for circulating a cooling liquid is provided inside the electrode holder and the electrode tip.   The said electrode tip is provided in the said electrode holder so that attachment or detachment is possible, The joining apparatus of the metal member of any one of Claim 1 thru | or 3 characterized by the above-mentioned. The metal member joining apparatus according to claim 3 , wherein the cooling liquid supply means has a through-hole penetrating a tip portion of the electrode tip.

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