JP6873777B2 - How to join metal members - Google Patents

Description

The present invention relates to a bonding how the metal member to be joined with the first metallic member and a second metal member having a melting point lower than the first metal member.

For example, Patent Document 1 discloses a joining method for joining a first metal member and a second metal member without using a method such as press-fitting or shrink-fitting, which tends to limit the degree of freedom in shape design. There is. That is, in this joining method, the first metal member and the second metal member are brought into contact with each other via a brazing material, and energization is performed while pressurizing in a direction close to each other. Heat is transferred from the first metal member and the second metal member generated by this to the brazing material, and the brazing material is melted and discharged from between the first metal member and the second metal member. As a result, a bonded metal member in which the first metal member and the second metal member are liquid-phase diffusion bonded is obtained.

Japanese Unexamined Patent Publication No. 11-170034

In the above joining method, the relative joining positions of the first metal member and the second metal member are determined only by the pressurizing timing based on a predetermined time. Therefore, for example, when the shapes of the first metal member and the second metal member, the thickness of the brazing material, and the like vary, the first metal member and the second metal member have a desired positional relationship by pressurization. There is a concern that it will be difficult to bring them close to each other or to sufficiently melt and discharge the brazing material. Further, for example, when pressurization and energization are performed in a state where the positions and directions in which the first metal member and the second metal member are brought into contact with each other are deviated, the first metal member and the first metal member are deviated from each other. There is a concern that the second metal member will be joined and the quality of the obtained joined metal member will deteriorate.

The present invention has been made to solve the above-mentioned problems, and the first metal member and the second metal member are highly accurate regardless of the variation in shape, the contact position and orientation deviation at the time of joining, and the like. bonding to provide a bonded how the metal member capable of obtaining a bonding metal members with excellent quality.

In order to achieve the above object, the present invention has an outer peripheral portion of an annular first metal member and an opening peripheral edge portion which is a peripheral edge portion of an opening provided in the second metal member having a melting point lower than that of the first metal member. A method of joining metal members, in which a first positioning surface provided on the outer periphery of the first metal member and a second positioning surface provided on the opening peripheral edge of the second metal member are spaced apart from each other. The first metal member is in a state where the corners of the convex portions protruding from the second joint surface of the second metal member are in line contact with the first joint surface of the first metal member. By energizing the second metal member while applying a pressing force, the molten convex portion is discharged from between the first joint surface and the second joint surface, and the first metal member and the first metal member are discharged. The first step of bringing the two metal members close to each other, and at the same time when the first positioning surface and the second positioning surface come into contact with each other, the energization is stopped and the application of the pressing force is stopped, so that the first joint surface the second bonding surface becomes junction and, possess contact the first positioning surface and a second positioning surface has and a second step of obtaining a bonding metal members to be non-melting site, from each other, the first joint surface The outer diameter of the first metal member is expanded from one end side, which is the front side, to the other end side, which is the rear side, when the first metal member and the second metal member are brought close to each other in the first step. It has a tapered shape with a diameter, the second joint surface has a tapered shape along the first joint surface, and the first positioning surface is continuously provided on one end side of the first joint surface. The second positioning surface is continuously provided on one end side of the second joint surface, and the first positioning surface and the second positioning surface are tapered more than the first joint surface and the second joint surface. It has a tapered shape with a large angle, and the convex portion projects from the second joint surface toward the axial side of the opening. In the first step, the convex portion melts from the corner portion and the first By contacting the joint surface, as the first metal member and the second metal member come closer to each other, the contact area between the first joint surface and the convex portion becomes the opening along the first joint surface. will expand in the radial direction, the whole of the joint portion which is formed in the second step is characterized tapered der Rukoto along said first joint surface.

In this method of joining metal members, a first positioning surface and a first joining surface are provided on the first metal member, and a second positioning surface and a second joining surface are provided on a second metal member having a melting point lower than that of the first metal member. It is provided. The first positioning surface and the second positioning surface are formed so that the first metal member and the second metal member have a desired joint positional relationship when they come into contact with each other.

When the first metal member and the second metal member are joined to each other, a joint portion is formed between the first joint surface and the second joint surface. On the other hand, before the first metal member and the second metal member are joined, that is, in a state where the joining portion is not formed, a convex portion is formed on the second joining surface.

Specifically, in this method of joining metal members, first, the first positioning surface and the second positioning surface are made to face each other at intervals, and the convex portion protruding from the second joining surface is brought into contact with the first joining surface. In this state, the first metal member and the second metal member are energized while applying a pressing force. As a result, the first metal member and the second metal member can be brought close to each other while discharging the molten convex portion from between the first joint surface and the second joint surface.

In this way, when the first metal member and the second metal member are brought close to each other and the first positioning surface and the second positioning surface come into contact with each other, only the first joint surface and the convex portion up to that point are in contact with each other. Compared with the case, the contact area between the first metal member and the second metal member increases sharply. Therefore, the current value per unit area flowing between the first metal member and the second metal member becomes smaller (contact resistance becomes smaller). On the other hand, the heat capacity of the contact surfaces of the first metal member and the second metal member becomes large. As a result, the amount of heat required to melt the second metal member cannot be obtained, and the melting of the second metal member is temporarily stopped.

Therefore, by stopping the energization in response to the contact between the first positioning surface and the second positioning surface, the second positioning surface is prevented from melting and the first positioning surface and the second positioning surface are brought into contact with each other. Can be made to. That is, unlike the case where the relative joining positions of the first metal member and the second metal member are determined only by the pressurization timing based on a predetermined time, for example, the first metal member and the second metal member are second. The metal member can be joined in a state of being positioned with high accuracy so as to have a desired positional relationship.

From the above, according to this method of joining metal members, when the shapes of the first metal member and the second metal member are different, or the contact position and orientation of the first metal member and the second metal member are deviated. Even when pressurization and energization are performed in this state, the first metal member and the second metal member are joined with high precision so as to have a desired positional relationship to obtain a joined metal member having excellent quality. be able to.

In the method for joining metal members, the first metal member has the first positioning surface and the second positioning surface facing each other at intervals, and the convex portion is in contact with the first joining surface. It is preferable that the pressing force is applied to the second metal member in a state where the energization is stopped, and the energization is started when the pressing force reaches a predetermined magnitude. In this case, a contact resistance can be satisfactorily generated between the first joint surface and the convex portion to melt the convex portion. As a result, a joint portion can be satisfactorily formed between the first joint surface and the second joint surface, so that the quality of the metal member to be joined can be further improved.

In the method for joining metal members, it is preferable to stop energization immediately before or at the same time when the first positioning surface and the second positioning surface come into contact with each other. In this case, since it is possible to more effectively prevent the second positioning surface from melting, the positioning of the first metal member and the second metal member by the contact between the first positioning surface and the second positioning surface Can be performed with higher accuracy. As a result, the quality of the bonded metal member can be further improved.

In the method for joining metal members, it is preferable that the first metal member is made of an iron-based material and the second metal member is made of an aluminum-based material. As described above, in this metal member joining method, the first metal member and the second metal member are heated further by stopping the energization in response to the contact between the first positioning surface and the second positioning surface. It can be avoided. Therefore, the diffusion of iron and aluminum can be suppressed, and the formation of a brittle intermetallic compound between the first metal member and the second metal member can be suppressed. That is, even a first metal member made of an iron-based material and a second metal member made of an aluminum-based material can be joined with high strength and high accuracy.

In the method for joining metal members, the first metal member preferably contains a high electrical conductivity material having a higher electrical conductivity than iron. In this case, it is possible to generate heat more effectively at the contact surface between the first metal member and the second metal member than inside the first metal member when energized. Therefore, a joint portion can be satisfactorily formed between the first joint surface and the second joint surface, and the joint strength between the first metal member and the second metal member can be improved.

In the above-mentioned method for joining metal members, a copper-based material can be mentioned as a preferable example of a high electrical conductivity material. In this case, it is possible to easily obtain the above-mentioned effects without increasing the cost.

In the method for joining metal members, the first metal member is a valve seat, the second metal member is a cylinder head body, and the valve is located on the peripheral edge of a port opening provided in the cylinder head body. It is preferable to join the sheets to obtain the joined metal member.

In this case, as described above, the first joint surface of the valve seat and the second joint surface of the cylinder head body can be joined by resistance welding. Therefore, unlike the case where the valve seat and the cylinder head main body are joined by press fitting or shrink fitting, sufficient joining strength can be obtained in a small fixed space. In other words, because the thickness of the valve seat can be reduced, the degree of freedom in the orientation of the port can be improved, and the distance between the valve contact surface of the valve seat and the cooling jacket can be shortened to improve the cooling efficiency of the valve, etc. It becomes possible to increase.

Further, according to this joining method, as described above, the valve seat and the cylinder head can be joined with high accuracy in a desired positional relationship, that is, without a gap, so that the thermal conductivity of the valve seat and the cylinder head body can be joined. Can be effectively enhanced. This also makes it possible to improve the cooling efficiency of the valve or the like via the valve seat.

Further, the present invention is a bonded metal member in which a valve seat is joined to the opening peripheral edge of a port provided in the cylinder head body so as to open toward the combustion chamber, and is on the valve contact surface side of the valve seat. The first joint surface provided on the outer periphery of the valve and the second joint surface provided on the combustion chamber side of the opening peripheral edge form a joint portion by welding, and the side opposite to the valve contact surface of the valve seat. A non-melted portion is formed in a state where the first positioning surface provided in the above and the second positioning surface provided on the side opposite to the combustion chamber of the opening peripheral edge are in contact with each other.

This bonded metal member can be obtained by applying the above-mentioned method for joining metal members. Therefore, even if the shapes of the valve seat and the cylinder head body are uneven, or even if the contact position and orientation before joining each other are different, the valve seat and the cylinder head body are positioned at a desired position. The relationship can be joined with high precision. That is, the quality of the bonded metal member can be easily improved.

Further, in this bonded metal member, since the valve seat and the cylinder head body are joined via a joining portion by welding, the degree of freedom in the orientation of the port and the like can be improved for the same reason as described above, and the valve and the like can be used. It becomes possible to increase the cooling efficiency of the.

According to the present invention, the first metal member and the second metal member are brought into a desired positional relationship by avoiding melting of the first positioning surface and the second positioning surface and bringing them into contact with each other. It is possible to join with high precision in the state of being positioned at. Therefore, the quality is excellent even when the shapes of the first metal member and the second metal member are uneven, or when pressurization and energization are performed in a state where the contact positions and directions of the first metal member are different from each other. It is possible to obtain a bonded metal member.

FIG. 1 is a schematic cross-sectional view of a main part of a metal joint member (cylinder head) according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the first metal member (valve seat) and the second metal member (cylinder head body) before joining. FIG. 3 is an explanatory diagram illustrating a state in which the first joint surface of the first metal member and the convex portion provided on the second joint surface of the second metal member are brought into contact with each other. FIG. 4 is an explanatory diagram illustrating a state in which the convex portion of FIG. 3 is melted and the first metal member and the second metal member are brought close to each other. FIG. 5 is an explanatory view illustrating a state in which the first metal member and the second metal member of FIG. 4 are brought closer to each other and the first positioning surface and the second positioning surface are brought into contact with each other. FIG. 6 is a timing chart showing a control method such as energization and pressurization.

A method for joining metal members and a suitable embodiment for joining metal members according to the present invention will be described in detail with reference to the accompanying drawings.

In the following, as shown in FIGS. 1 to 5, the metal member to be joined according to the present embodiment is the cylinder head 10, and the method of joining the metal member according to the present embodiment is different from that of the first metal member which is the valve seat 12. , An example applied in the case of obtaining the cylinder head 10 by joining the second metal member which is the cylinder head main body 14 will be described.

However, the bonded metal member is not limited to the cylinder head 10. Further, the first metal member and the second metal member to which the metal member joining method can be applied are not limited to the valve seat 12 and the cylinder head main body 14. The first metal member and the second metal member may be made of a material that can be joined by energization and pressurization, and the melting point of the second metal member may be lower than that of the first metal member. Further, the bonded metal member may be any one obtained by joining such a first metal member and a second metal member, and those having various shapes and uses can be adopted.

As shown in FIG. 1, the cylinder head 10 (joint metal member) includes, for example, an annular valve seat 12 (first metal member) made of a sintered body of an iron-based material such as a steel material, pure aluminum, or, for example. It mainly includes a cylinder head main body 14 (second metal member) made of an aluminum-based material such as an aluminum alloy. In this embodiment, the valve seat 12 further contains a high electrical conductivity material such as a copper-based material.

The cylinder head main body 14 is formed with an intake port 18 and an exhaust port 20 (hereinafter, collectively referred to as ports) whose one end side opens toward the combustion chamber 16, respectively. Valve seats 12 are joined to the opening peripheral edges 22 of these ports.

Specifically, as shown in FIGS. 1 and 2, the first joint surface 24 provided on the outer periphery of the valve seat 12 on the valve contact surface 12a side and the combustion chamber 16 side of the opening peripheral edge portion 22 are provided. The second joint surface 26 and the second joint surface 26 form a joint portion 28 by welding. Further, the first positioning surface 30 provided on the side opposite to the valve contact surface 12a of the valve seat 12 and the second positioning surface 32 provided on the side opposite to the combustion chamber 16 of the opening peripheral edge portion 22 are in contact with each other. The non-melted portion 34 is formed in this state. The details of the valve seat 12, the opening peripheral portion 22, and the like will be described later.

Each of the ports can be opened and closed by seating or separating the valve 36 from the valve contact surface 12a of the valve seat 12 joined to the opening peripheral edge portion 22 of the cylinder head main body 14. Further, a cooling jacket 38 for circulating cooling water is provided between the intake port 18 and the exhaust port 20 of the cylinder head main body 14, and the heat of the valve 36 is cooled through the valve seat 12 and the cylinder head main body 14. By transmitting to the jacket 38, it is possible to satisfactorily cool the valve 36 and the like.

The cylinder head 10 according to the present embodiment is basically configured as described above. Next, a step of obtaining the cylinder head 10 by the metal member joining method according to the present embodiment will be described with reference to FIGS. 2 to 6.

As shown in FIG. 2, the valve seat 12 is inserted into the opening peripheral edge portion 22 of the cylinder head main body 14 from one end side in the axial direction (X side in the arrow direction, hereinafter also simply referred to as one end side). The valve seat 12 is provided with a first positioning surface 30 on the outer circumference on one end side thereof, and is on the other end side in the axial direction from the first positioning surface 30 (Y side in the arrow direction, hereinafter also simply referred to as the other end side). A first joint surface 24 is provided on the outer periphery of the above.

The first positioning surface 30 and the first joint surface 24 have a tapered shape in which the diameter increases from one end side to the other end side at different taper angles, and the taper angle of the first positioning surface 30 is the first joint surface 24. It is set larger than the taper angle of.

The opening peripheral edge portion 22 of the cylinder head main body 14 before joining with the valve seat 12 is provided with a second positioning surface 32 on the inner circumference on one end side thereof, and is provided on the other end side of the second positioning surface 32. The convex portion 40 protrudes from the second joint surface 26.

The second positioning surface 32 has a tapered shape in which the diameter increases from one end side to the other end side so that the taper angle is substantially equal to that of the first positioning surface 30. The first positioning surface 30 and the second positioning surface 32 are set so that the valve seat 12 and the cylinder head main body 14 have a desired joint positional relationship when they come into contact with each other.

The convex portion 40 has a peripheral surface 40a extending from the other end of the second positioning surface 32 along the axial direction by a predetermined length, and the other end of the peripheral surface 40a opposite to the axial center of the opening peripheral edge portion 22. It has an end face 40b extending along the radial direction toward the side. Further, a corner portion 40c is formed by a peripheral surface 40a and an end surface 40b that are orthogonal to each other.

The second joint surface 26 extends along the first joint surface 24 when the valve seat 12 and the cylinder head main body 14 are joined. On the other hand, the second joint surface 26 is partially or wholly covered by the convex portion 40 before the valve seat 12 and the cylinder head main body 14 are joined.

In this method of joining metal members, first, as shown in FIG. 3, the first positioning surface 30 and the second positioning surface 32 are made to face each other at intervals, and the corner portion of the convex portion 40 is placed on the first joining surface 24. The valve seat 12 and the cylinder head main body 14 are set between one electrode 50 and the other electrode (not shown) of the set of electrodes with the 40c in contact with each other.

A set of electrodes is connected to a power source via, for example, a capacitor, and can be driven in a direction close to or separated from each other by a drive mechanism such as a pressure cylinder (both not shown). Therefore, by driving this set of electrodes in the directions close to each other, it is possible to apply a pressing force to the valve seat 12 and the cylinder head main body 14 in the directions close to each other.

As shown by the solid line A in the time chart of FIG. 6, the pressing force starts to be applied at time T1 and gradually increases, and at time T2, the valve seat 12 and the cylinder head body 14 are resistance welded. It becomes P1 of a suitable predetermined size. As the pressing force increases, as shown by the broken line B in FIG. 6, the pushing amount of the valve seat 12 with respect to the opening peripheral edge portion 22 of the cylinder head main body 14 also gradually increases.

Then, the energization of the valve seat 12 and the cylinder head main body 14 is started from the time T3 immediately after the time T2 when the pressing force reaches P1. At this time, the magnitude of the pressing force is maintained at P1. Along with this, as shown by the alternate long and short dash line C in FIG. 6, the value of the current flowing between one electrode 50 and the other electrode (not shown) increases. Further, as shown by the broken line D in FIG. 6, the resistance value between one electrode 50 and the other electrode (not shown) increases.

By this energization, a current flows from the valve seat 12 to the cylinder head main body 14 through the contact portion between the first joint surface 24 and the convex portion 40. The contact portion between the valve seat 12 and the cylinder head body 14 generates heat due to the electrical resistance of the contact portion between the first joint surface 24 and the convex portion 40.

As described above, the contact between the first joint surface 24 and the convex portion 40 is started by starting to apply the pressing force in the state where the energization is stopped and starting the energizing from the time T3 after the pressing force reaches P1. It becomes possible to heat the part satisfactorily.

At this time, the valve seat 12 and the cylinder head main body 14 are in contact with each other in a small area of the first joint surface 24 and the corner portion 40c of the convex portion 40, and the valve seat 12 contains a high electrical conductivity material. As a result, heat can be generated more effectively at the contact portion between the first joint surface 24 and the convex portion 40 than inside the valve seat 12 or the cylinder head main body 14.

Further, the cylinder head main body 14 has a lower melting point than the valve seat 12. Therefore, the contact portion between the first joint surface 24 and the convex portion 40, which has been heated by the above heat, reaches the melting point of the cylinder head main body 14 (convex portion 40) at time T4, and the convex portion 40 begins to melt. .. As a result, as described above, the pushing amount of the valve seat 12 with respect to the opening peripheral edge portion 22 starts to increase again while the magnitude of the pressing force is maintained at P1.

That is, as shown in FIG. 4, the valve seat 12 and the opening peripheral edge portion 22 can be brought close to each other while discharging the molten convex portion 40 from between the first joint surface 24 and the second joint surface 26. .. Then, as shown in FIG. 5, when substantially the entire convex portion 40 is melted, a joint portion 28 is formed between the first joint surface 24 and the second joint surface 26, and the first positioning surface 30 and the first positioning surface 30 are formed. 2 The positioning surfaces 32 come into contact with each other.

When the first positioning surface 30 and the second positioning surface 32 come into contact with each other, the valve seat 12 and the opening peripheral edge portion 22 are in contact with each other as compared with the case where only the first joint surface 24 and the convex portion 40 are in contact with each other. The contact area increases rapidly. Therefore, the current value per unit area flowing between the valve seat 12 and the opening peripheral portion 22 becomes small (contact resistance becomes small). On the other hand, the heat capacity of the contact surface between the valve seat 12 and the opening peripheral edge portion 22 becomes large. As a result, it becomes impossible to obtain the amount of heat required to melt the cylinder head main body 14, and the melting of the cylinder head main body 14 is temporarily stopped.

Therefore, the cylinder head main body 14 is further melted by stopping the energization at the time T5 immediately before the contact between the first positioning surface 30 and the second positioning surface 32 or at the same timing as the contact, in other words. , It is possible to prevent the second positioning surface 32 from melting.

When the first positioning surface 30 and the second positioning surface 32 come into contact with each other, the voltage between one electrode 50 and the other electrode (not shown) drops sharply. Therefore, for example, this voltage drop should be detected. Therefore, it is possible to detect that the first positioning surface 30 and the second positioning surface 32 are in contact with each other. Therefore, the energization stop may be controlled by detecting this voltage drop, or the energization stop may be controlled by detecting the timing of the voltage drop in advance.

That is, as shown in FIG. 6, when the energization is stopped at the time T5, the state where the first positioning surface 30 and the second positioning surface 32 are in contact with each other can be maintained, and the amount of pushing of the valve seat 12 with respect to the opening peripheral edge portion 22. Does not increase any further. The current value and the resistance value decrease as the energization is stopped. Further, in the present embodiment, the application of the pressing force is stopped at the same time as the energization is stopped.

As a result, the first positioning surface 30 and the second positioning surface 32 can be brought into good contact with each other, and the valve seat 12 and the opening peripheral edge portion 22 can be positioned so as to have a desired positional relationship. Then, in this state, the first joint surface 24 and the second joint surface 26 can be joined via the joint portion 28 formed between them.

In this way, after joining the valve seat 12 and the opening peripheral edge portion 22 of the cylinder head main body 14, the valve seat 12 is machined to form the valve contact surface 12a, whereby the cylinder head 10 is obtained. Be done. That is, in the cylinder head 10, a joint portion 28 is formed by welding between the first joint surface 24 and the second joint surface 26, and the first positioning surface 30 and the second positioning surface 32 are in contact with each other. It becomes a non-melted portion 34 that only contacts.

From the above, according to this metal member joining method, for example, the relative joining position of the valve seat 12 and the opening peripheral edge portion 22 is determined only by the pressurization timing based on a predetermined time. However, the valve seat 12 and the opening peripheral edge portion 22 can be joined in a positioned state. Therefore, when the shapes of the valve seat 12 and the opening peripheral edge 22 and the like are uneven, or when pressurization and energization are performed in a state where the contact position and direction of the first joint surface 24 and the convex portion 40 are deviated. Even so, the cylinder head 10 having excellent quality can be obtained by joining the valve seat 12 and the opening peripheral edge portion 22 with high accuracy so as to have a desired positional relationship.

As described above, in the cylinder head 10, the valve seat 12 is made of an iron-based material, and the cylinder head main body 14 is made of an aluminum-based material. Even in this case, as described above, the valve seat 12 and the cylinder head body 14 can be heated further by stopping the energization in response to the contact between the first positioning surface 30 and the second positioning surface 32. It can be avoided. As a result, the diffusion of iron and aluminum can be suppressed, so that the formation of a brittle intermetallic compound between the valve seat 12 and the cylinder head main body 14 can be suppressed. As a result, the valve seat 12 and the cylinder head main body 14 can be joined with high strength and high accuracy.

As described above, in the cylinder head 10, the first joint surface 24 of the valve seat 12 and the second joint surface 26 of the cylinder head main body 14 are joined by resistance welding. Therefore, unlike the case where the valve seat 12 and the cylinder head main body 14 are joined by press fitting, shrink fitting, or the like, sufficient joining strength can be obtained in a small fixed space. That is, since the thickness of the valve seat 12 can be reduced, the degree of freedom in the orientation of the port and the like can be improved, and the distance between the valve contact surface 12a of the valve seat 12 and the cooling jacket 38 can be shortened to reduce the valve. It is possible to increase the cooling efficiency of 36 or the like.

Further, as described above, since the valve seat 12 and the cylinder head main body 14 can be joined with high accuracy in a desired positional relationship, that is, without a gap, the thermal conductivity of the valve seat 12 and the cylinder head main body 14 is effective. Can be enhanced. This also makes it possible to improve the cooling efficiency of the valve 36 and the like via the valve seat 12.

The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof.

For example, in the above embodiment, the valve seat 12 includes a high electrical conductivity material, but the high electrical conductivity material is not an essential component. Further, the high electric conductivity material is not limited to the copper-based material, and may be any material having a higher electric conductivity than the material of the valve seat 12.

Further, in the method of joining metal members according to the above embodiment, pressurization and energization are performed based on the timing chart shown in FIG. 6, but the timing of pressurization and energization is particularly limited to this. is not it. For example, in the above embodiment, the valve seat 12 and the cylinder head body 14 are energized from the time T3 immediately after the time T2 when the pressing force reaches P1, but before the time T2 or at the time T2. Energization may be started at the same time.

Further, in the above embodiment, the energization is stopped immediately before the contact between the first positioning surface 30 and the second positioning surface 32, or at the time T5 which is the timing at the same time as the contact. Is not particularly limited as long as the timing does not melt the second positioning surface 32.

Further, in the above embodiment, the timing of stopping the application of the pressing force is the same as the stop of energization, but the present invention is not particularly limited to this. For example, the application of the pressing force may be stopped immediately after the energization is stopped, or the application of the pressing force may be stopped after a predetermined time has elapsed since the energization was stopped.

10 ... Cylinder head 12 ... Valve seat 12a ... Valve contact surface 14 ... Cylinder head body 16 ... Combustion chamber 18 ... Intake port 20 ... Exhaust port 22 ... Opening peripheral edge 24 ... First joint surface 26 ... Second joint surface 28 ... Joining part 30 ... First positioning surface 32 ... Second positioning surface 34 ... Non-melting part 36 ... Valve 38 ... Cooling jacket 40 ... Convex part 40a ... Peripheral surface 40b ... End face 50 ... Electrode

Claims (6)

A method for joining a metal member, which joins an outer circumference of an annular first metal member and an opening peripheral edge portion which is a peripheral edge portion of an opening provided in the second metal member having a melting point lower than that of the first metal member.
The first positioning surface provided on the outer periphery of the first metal member and the second positioning surface provided on the peripheral edge of the opening of the second metal member are made to face each other at a distance, and the first metal member. While applying pressure to the first metal member and the second metal member in a state where the corners of the convex portions protruding from the second metal member of the second metal member are in line contact with the first metal member of the above. A first step of bringing the first metal member and the second metal member close to each other while discharging the molten convex portion from between the first joint surface and the second joint surface by energizing.
By stopping the energization and the application of the pressing force at the same time when the first positioning surface and the second positioning surface come into contact with each other, the first joint surface and the second joint surface become joint portions and become mutual. The second step of obtaining a bonded metal member in which the contacted first positioning surface and the second positioning surface are non-melting portions, and
Have a,
The first metal is formed on the first metal from one end side, which is the front side when the first metal member and the second metal member are brought close to each other in the first step, toward the other end side, which is the rear side. It has a tapered shape that expands the outer diameter of the member.
The second joint surface has a tapered shape along the first joint surface.
The first positioning surface is continuously provided on the one end side of the first joint surface.
The second positioning surface is continuously provided on the one end side of the second joint surface.
The first positioning surface and the second positioning surface have a tapered shape having a taper angle larger than that of the first joint surface and the second joint surface.
The convex portion protrudes from the second joint surface toward the axial side of the opening.
In the first step, the convex portion comes into contact with the first joint surface while melting from the corner portion, so that the first metal member and the second metal member come closer to each other, and the first joint surface becomes closer. The contact area between the metal and the convex portion expands in the radial direction of the opening along the first joint surface.
The whole of the joint portion which is formed in the second step, the bonding method of the metal member, wherein a tapered der Rukoto along said first joint surface. In the method for joining metal members according to claim 1,
With respect to the first metal member and the second metal member in a state where the first positioning surface and the second positioning surface face each other at a distance and the convex portion is in contact with the first joint surface. , A method for joining a metal member, characterized in that the pressing force is applied in a state where the energization is stopped, and the energization is started when the pressing force reaches a predetermined magnitude. In the method for joining metal members according to claim 1 or 2.
A method for joining metal members, wherein the first metal member is made of an iron-based material, and the second metal member is made of an aluminum-based material. In the method for joining metal members according to claim 3,
The first metal member is a method for joining a metal member, which comprises a high electrical conductivity material having a higher electrical conductivity than iron. In the method for joining metal members according to claim 4,
A method for joining metal members, wherein the high electrical conductivity material is a copper-based material. In the method for joining metal members according to any one of claims 1 to 5,
The first metal member is a valve seat.
The second metal member is a cylinder head body.
A method for joining a metal member, which comprises joining the valve seat to a peripheral portion of an opening of a port provided in the cylinder head main body to obtain the joined metal member.

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