JP2013224469A - Structure and method for joining of dissimilar metal member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining structure and joining method that can secure the strength of a fixed part when a joint is fixed which is formed of different materials of, for example, an impeller shell and a front cover by means of cold spray.SOLUTION: A first base material is formed of metal. A second base material is formed of metal different from the first base metal, and a metal layer is formed in the vicinity of a joint between the first and second base materials by means of cold spray using the same kind of metal particles as the first base material. The first base material and the metal layer of the second base material are fixed by formation of a metal layer by means of the cold spray.

Description

  The present invention relates to a joining structure and joining method for dissimilar metal substrates.

  The following Patent Document 1 discloses a technique for forming a metal layer by a cold spray method.

JP 2010-234756 A

  For example, the impeller shell and the front cover can be integrally fixed by forming a metal layer by a cold spray method at a joint portion between the impeller shell and the front cover of the torque converter storage container. However, the impeller shell and the front cover may be made of different materials. If the impeller shell and the front cover are fixed with the same metal particle firing conditions, the adhesion of the metal layer cannot be ensured, and the impeller There was a risk that the strength of the joint between the shell and the front cover would be insufficient.

  The present invention has been made paying attention to the above-mentioned problem, and is formed of a different material by a cold spray method, for example, when fixing a joint portion between an impeller shell and a front cover, the strength of the fixing portion is ensured. It is an object of the present invention to provide a bonding structure and a bonding method that can be used.

  In order to achieve the above object, in the present invention, the first base material formed of metal and the first base material are formed of a metal different from the first base material, The second base material on which the metal layer was formed by the cold spray method using the same kind of metal particles, and the first base material and the metal layer of the second base material were fixed by forming the metal layer by the cold spray method.

  Therefore, the adhesiveness between each substrate and the metal layer can be enhanced, and the strength of the joint portion by the metal layer can be ensured.

It is a fragmentary sectional view of the torque converter of an example. It is an expanded sectional view of the joined part of the impeller shell and front cover of an Example. It is a figure which shows the fixing procedure of the junction part of the impeller shell and front cover of an Example. It is a figure which shows the fixing procedure of the junction part of the impeller shell and front cover of an Example.

In the following embodiments, an impeller shaft and a front cover in a torque converter will be described as examples of the joining structure and joining method of two different metal base materials.
〔Example〕
[Overall configuration of torque converter]
FIG. 1 is a partial cross-sectional view of the torque converter 1. As main elements constituting the torque converter 1, a pump impeller 2, a turbine runner 3, a stator 5 including a one-way clutch 4, and a lock-up clutch 7 are provided. Each of these elements is accommodated in the torque converter storage container 6.
The torque converter storage container 6 includes an impeller shell 60 (second base material) and a front cover 61 (first base material). The impeller shell 60 is made of aluminum metal, and the front cover 61 is made of iron metal. The opening 60a on the engine output shaft side of the impeller shell 60 and the opening 61a on the transmission input shaft side of the front cover 61 are fixed by a cold spray method. This fixing method will be described in detail later.
The pump impeller 2 includes a blade-like impeller blade 20 provided on the inner wall of the impeller shell 60.
The turbine runner 3 is arranged at a position facing the pump impeller 2 and includes a turbine shell 30 and a blade-like turbine blade 31 provided inside the turbine shell 30.
The stator 5 is provided between the pump impeller 2 and the turbine runner 3, and includes a base 50 and a blade-shaped stator blade 51 extending in the radial direction from the base 50. Base 50 is provided between transmission housing via one-way clutch 4. The one-way clutch 4 is axially constituted by a needle bearing 80 disposed between an impeller hub 62 fixed to the impeller shell 60 and a needle bearing 81 disposed between the turbine hub 32 fixed to the turbine shell 30. Is positioned.
The lock-up clutch 7 includes a lock-up piston 70 that is slidably held in the axial direction on the turbine hub 32, and a torsion damper 71 that is fixed to the turbine shell 30 with a rivet 82.
The torque converter storage container 6 is filled with oil, and a torque amplifying action is generated by the flow of oil by the blades of the pump impeller 2, the turbine runner 3, and the stator 5.

[Joint structure between impeller shell and front cover]
FIG. 2 is an enlarged cross-sectional view of the vicinity of the opening 60a of the impeller shell 60 on the engine output shaft side and the opening 61a of the front cover 61 on the transmission input shaft side. In order to make the drawing easier to understand, the components inside the torque converter storage container 6 are not shown.
The outer diameter of the opening 60a of the impeller shell 60 is smaller than the inner diameter of the opening 61a of the front cover 61, and constitutes a small diameter portion 60b. On the side opposite to the front cover 61 of the small diameter portion 60b, it is formed smaller than the outer diameter (outer diameter portion 61b) of the opening 61a of the front cover 61 and larger than the outer diameter of the small diameter portion 60b. Is configured. The outer periphery of the small diameter portion 60b of the impeller shell 60 and the inner periphery of the opening 61a of the front cover 61 are fitted. Therefore, a step portion is formed at the joint portion between the impeller shell 60 and the front cover 61. The metal layer 6b is formed and deposited by the cold spray method from the outer peripheral surface of the large diameter portion 60c of the impeller shell 60 to the outer diameter portion 61b of the front cover 61. The impeller shell 60 and the front cover 61 are integrally fixed by the metal layer 6b. Similar to the front cover 61, the metal layer 6b is formed of iron-based metal.
The cold spray method is a technique mainly used when forming a film on a substrate. The metal particles heated in the range below the melting point are placed on a high-speed flow of inert gas and collide with the base material, and physical bonds are obtained by the anchor effect. This makes it possible to form a film that suppresses oxidation. In the present embodiment, this is used as a fixing method between the opening 60a on the engine output shaft side of the impeller shell 60 and the opening 61a on the transmission input shaft side of the front cover 61.

[Fixing method 1 with cold spray]
FIG. 3 is a diagram showing a procedure for fixing the impeller shell 60 and the front cover 61 by cold spray.
As shown in FIG. 3A, first, the impeller shell 60 and the front cover 61 are assembled. Next, as shown in FIG. 3B, the metal layer 6a is formed only on the impeller shell 60 by cold spray. As shown in FIG. 3C, the metal layer 6a is laminated to the extent that it substantially coincides with the outer diameter portion 61b of the front cover 61. At this time, the conditions (such as the pressure and temperature of the inert gas) of the metal particles fired from the spray gun are set to appropriate conditions for bringing the iron-based metal particles into close contact with the aluminum-based metal. Next, as shown in FIG. 3D, the metal layer 6 b is formed by cold spraying from the metal layer 6 a formed on the impeller shell 60 to the front cover 61. At this time, the conditions (such as the pressure and temperature of the inert gas) of the metal particles fired from the spray gun are set to appropriate conditions for bringing the iron-based metal particles into close contact with the iron-based metal.

[Fixing method 2 by cold spray]
A method different from the above fixing method will be described. FIG. 4 is a diagram showing a procedure of a method for fixing the impeller shell 60 and the front cover 61 by cold spray.
As shown in FIG. 4A, first, before assembling the impeller shell 60 and the front cover 61, the metal layer 6 a is formed only on the impeller shell 60. At this time, the conditions (such as the pressure and temperature of the inert gas) of the metal particles fired from the spray gun are set to appropriate conditions for bringing the iron-based metal particles into close contact with the aluminum-based metal. Next, as shown in FIG. 4B, the metal layer 6a attached to the small diameter portion 60b of the impeller shell 60 is removed by machining or the like. Next, as shown in FIG. 4C, the front cover 61 is assembled to the impeller shell 60. Next, as shown in FIG. 4D, the metal layer 6 b is formed by cold spraying from the metal layer 6 a formed on the impeller shell 60 to the front cover 61. At this time, the conditions (such as the pressure and temperature of the inert gas) of the metal particles fired from the spray gun are set to appropriate conditions for bringing the iron-based metal particles into close contact with the iron-based metal.

[Action]
A method of forming a metal film by a cold spray method is well known. By forming the metal layer between the two members in the same manner as forming the metal film, welding can be substituted for the fixing method between the two members.
In the cold spray method, in order to ensure the adhesion between the metal layer and the base material, it is necessary to change the conditions of the metal particles emitted from the spray gun depending on the material of the base material. However, when the impeller shell 60 is made of an aluminum-based metal and the front cover 61 is made of an iron-based metal, like the torque converter storage container 6 of the present embodiment, the metal layer 6b is formed under conditions that match one of the materials. The adhesion between the other metal and the metal layer 6b could not be ensured, and the strength at the joint between the impeller shell 60 and the front cover 61 might be insufficient.
Therefore, in this embodiment, the metal layer 6b is formed on the outer periphery of the joint portion between the impeller shell 60 and the front cover 61 by a cold spray method using metal particles of the same type (iron-based metal) as the front cover 61, and the impeller shell is thus formed. 60 and the front cover 61 were fixed. More specifically, the metal layer 6a is formed on the impeller shell 60 formed of a different kind of metal (aluminum metal) from the metal particles that are iron-based metal, and then the metal layer 6a formed on the impeller shell 60 and The metal layer 6b is formed on the front cover 61.

[effect]
In the torque converter storage container 6 of the present embodiment, when the metal layer 6a is formed on the impeller shell 60, the metal layer 6a is set to an appropriate condition for closely attaching the iron-based metal particles to the aluminum-based metal, and is formed on the impeller shell 60. When the metal layer 6b is formed on the metal layer 6a and the front cover 61, it is possible to fire the metal particles from the spray gun by setting the conditions appropriate for bringing the iron-based metal particles into close contact with the iron-based metal. . Therefore, the adhesion between the impeller shell 60 and the metal layer 60a can be enhanced, the adhesion between the front cover 61 and the metal layer 60b can be enhanced, and the strength of the joined portion by the metal layer 6b can be ensured.
As mentioned above, although this invention has been demonstrated based on the Example, the concrete structure of each invention is not limited to a present Example, Even if there is a design change etc. of the range which does not deviate from the summary of invention, It is included in the present invention.
For example, in this embodiment, the same kind of iron-based metal as that of the front cover 61 is used as the metal particles. However, the same kind of aluminum-based metal as that of the impeller shell 60 may be used. In that case, a metal layer may be formed on the front cover 61 side first, and then a metal layer may be formed between the metal layer formed on the front cover 61 and the impeller shell 60.

1 Torque converter
2 Pump impeller
3 Turbine runner
6 Torque converter containment
6a Joining groove
6b metal layer
60 Impeller shell
61 Front cover

Claims (2)

A first base formed of metal and a cold formed of a metal different from the first base and using metal particles of the same type as the first base in the vicinity of the joint with the first base A second substrate on which a metal layer is formed by a spray method;
A joining structure of dissimilar metal substrates, wherein the first substrate and the metal layer of the second substrate are fixed by forming a metal layer by the cold spray method. In the joining method of dissimilar metal substrates comprising a first substrate formed of metal and a second substrate formed of a metal different from the first substrate,
Forming a metal layer on the second base material under a first setting condition by a cold spray method using the same kind of metal particles as the first base material; and the first base material and the second base material Forming a metal layer under the second setting condition by the cold spray method, and bonding the metal layer,
A method for joining dissimilar metal substrates comprising:

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