JP2016203223A - Friction pressure-welding method and conjugate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction pressure-welding method and a conjugate which enable an amount of a base material extruded from a junction to be secured to obtain a favorable joint face even when one junction member secures not many of shrinking margins.SOLUTION: A first junction member 1, having an annular junction end face and having a recess 3 annularly formed in the outer periphery in a vicinity of the junction end face, and a second junction member 2, having an annular junction end face and having an annular junction end face with a wall thickness t2 substantially equal to the wall thickness t1 of the junction end face of the first junction member 1, are prepared to bring the first junction member 1 into friction pressure-welding with the second junction member 2, and the outer periphery of a junction is cut by friction pressure-welding so that the wall thickness t5 of the junction by friction pressure-welding may become thinner than the wall thicknesses t1,t2 in the junction end face at the preparation stage of the first junction member 1 and that of the second junction member 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a friction welding (friction welding) method, and more particularly to a friction welding method for a tubular member and a joined body obtained thereby.

As a method of friction welding the tubular member, for example, there are methods described in Patent Document 1 and Patent Document 2.
In patent document 1, it has a joining surface with respect to the thin pipe formed in the relatively small thickness, and the thin pipe formed in the relatively large thickness, and formed in the thickness smaller than the thickness of the thin pipe. A pipe joining method has been proposed in which a thick pipe is prepared, and a thin pipe and a thick pipe are joined by a friction welding method, whereby excellent durability and reliability can be obtained at the joining portion.

  In Patent Document 2, a joined body in which end surfaces of two joining members are joined by friction welding is formed on at least one of the two joining members, and a hollow portion that opens to the joining surfaces of the two joining members, and a hollow A groove portion formed in an annular shape at an axially spaced position from the joint surface and reducing the durability of the joined body without removing the bead generated on the inner peripheral side of the joint surface. Suppressed.

JP 2010-158712 A JP 2014-193471 A

Conventionally, including Patent Documents 1 and 2, various countermeasures against burrs generated from the joint surface have been proposed in friction welding. That is, at the time of friction welding, the base material of the end surface portion of the joining member is discharged to the outer peripheral side and the inner peripheral side of the joining surface by plastic flow to form burrs.
In Patent Document 1, since the thick pipe has a joint surface formed with a thickness smaller than the thickness of the thin pipe, the force received from the thick pipe side by the burrs generated in the joining process can be kept small. Thus, it is possible to suppress the formation of burrs having a sharp edge shape toward the thin pipe side, and to obtain excellent durability reliability at the joint portion.
In Patent Document 2, it is possible to reduce the stress generated in the root portion of the burr by providing a groove portion formed in an annular shape at a position spaced in the axial direction from the joint surface on the inner peripheral surface of the hollow portion, It is said that a decrease in durability can be suppressed without removing burrs.

  By the way, in friction welding, the end portion of the joining member is deformed, and the allowance is further determined by the amount of the base material pushed out from the joining portion. In order to obtain a good joint surface, it is necessary to increase the amount of the base material pushed out from the joint (the amount of burrs) to some extent. The margin is a joining member that has been worn out during friction welding, and is also referred to as a shrinkage margin. Usually, the same amount of shrinkage occurs in both joining members. However, according to the study by the present inventors, there is a case where a lot of shrinkage allowance cannot be secured for one joining member. In the conventional friction welding, such a problem has not been considered.

  The object of the present invention is to secure the amount of the base material (the amount of burrs) pushed out from the joint portion in order to obtain a good joint surface without securing a large shrinkage allowance for one joint member. It is an object to provide a friction welding method and a joined body.

  The present invention is a friction welding method in which a first joining member having an annular joint end face and a second joining member having an annular joint end face are friction welded and formed annularly on the outer periphery in the vicinity of the joint end face Preparing a first joining member having a recessed portion and a second joining member having a joint end face having substantially the same thickness as the thickness of the joint end face of the first joining member, Friction welding the joining member and the second joining member so that the thickness of the joint by friction welding is thinner than the thickness at the joint end face in the preparation stage of the first joining member and the second joining member. The outer periphery of the joint is cut by pressure welding.

According to the present invention, it is possible to ensure the amount of base material (the amount of burrs) pushed out from the joined portion without securing a large amount of shrinkage in the second joining member, and a good joining surface can be obtained. Can be obtained.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is explanatory drawing which shows a part of process of the friction welding method of this invention. It is explanatory drawing which shows a part of process of the friction welding method of this invention. It is a joint part enlarged view which shows a part of process of the friction welding method of this invention. It is explanatory drawing which shows a part of process of the friction welding method of this invention. It is a schematic diagram of a junction expanded section. It is a figure explaining the case where the friction welding method of this invention is applied to joining of the metal diaphragm and pressure guide tube in a high-pressure sensor. It is a figure explaining the case where the friction welding method of this invention is applied to joining of the metal diaphragm and pressure guide tube in a high-pressure sensor. It is a figure explaining the case where the friction welding method of this invention is applied to joining of the metal diaphragm and pressure guide tube in a high-pressure sensor. It is a figure explaining the friction welding apparatus used when implementing the friction welding method of the Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

The basic concept of the friction welding method of the present invention will be described with reference to FIGS.
In the case of friction welding the tubular joining members, the same amount of shrinkage is usually generated in both joining members. This is because the thickness at the joint end face of both joint members is the same. However, there are cases where a large amount of shrinkage cannot be ensured for one joining member, as in the case of the high pressure sensor described later (in the case of a high pressure sensor, it is difficult to ensure a large amount of shrinkage for the constituent members of the diaphragm). . On the other hand, in friction welding, in order to obtain a good joint surface, a large amount of base metal is discharged in order to sufficiently remove the oxide film and dirt on the metal surface, unevenness on the end face of the joint member, etc. from the joint. It is desirable to do. Moreover, in order to sufficiently refine the crystal grains in the joint, it is necessary to apply high temperature and high pressure, but if the high temperature and high pressure are applied, a large amount of base metal is discharged from the joint. . In other words, in order to obtain a good joint surface, high temperature and high pressure are required. However, if a large amount of shrinkage cannot be secured for one joint member, high temperature and high pressure are required to obtain a good joint surface. It is difficult to press.

  Therefore, as shown in FIG. 1, when a joining member that cannot secure a large amount of shrinkage is assumed to be the joining member 2, an annular recess is formed on the outer periphery in the vicinity of the joining portion of the other joining member 1 to which the joining member 2 is joined. To do. The joining members 1 and 2 are formed so that the thickness t1 at the end face of the joining member 1 and the thickness t2 at the end face of the joining member 2 have substantially the same thickness. The wall thicknesses t1 and t2 are set to be larger than the final wall thickness t5 of the joint obtained in the post-processing process (cutting process) after the friction welding process.

  The joining member 1 and the joining member 2 formed as described above are friction-welded. In the embodiment of FIG. 1, the bonding member 1 side is the rotation / pressure side, but the bonding member 2 side may be rotated / pressurized. Moreover, one joining member side may be rotated and the other joining member side may be pressurized from the outside.

  As with normal friction welding, the joining member is frictionally contacted with P0 pressure (preheating pressure) (preheating process), and then the joining member is friction welded with P1 pressure (friction pressure) larger than P0 pressure to obtain a desired heating state. (Friction heat generation process). Then, when the desired heating state suitable for joining is reached, the main shaft of the holding portion that holds the joining member 1 in rotation is braked to suddenly stop the rotation, and the P2 pressure (upset pressure) higher than the P1 pressure. And pressurizing with friction welding (upset process). FIG. 2 shows a state where the upset process is started. As shown in FIG. 2, a burr 4 is formed by discharging a certain amount of base material from the joint portion even in the frictional heat generation process.

  When the upset process is completed, as shown in FIG. 3, many base materials are pushed out (discharged) from the joint portion to the inner peripheral side and the outer peripheral side.

  In the present embodiment, in the frictional heat generation step, the temperature of the bonding portion of the bonding member 1 is heated to a temperature higher than the temperature of the bonding portion of the bonding member 2. That is, since the concave portion 3 is formed in the vicinity of the joint portion of the joining member 1, the cross-sectional area of the heat transfer path generated by frictional heat generation is smaller than that of the joining member 2, and the joining portion on the joining member 1 side is reduced. The temperature is heated to a higher temperature. In addition, the inner peripheral side of the bonded portion of the bonding member 1 has a higher temperature than the outer peripheral side. That is, the joining member 1 side and the inner peripheral side thereof are more softened.

  For this reason, as shown in FIG. 3, in the upset process, the amount of the base metal discharged from the joining portion is larger in the joining member 1 and more in the inner peripheral side of the joining member 1. . Reference numeral 4-1 denotes a first joining member side burr, and 4-2 denotes a second joining member side burr. In this upset process, a large amount of the base metal discharged from the joint is discharged from the joint member 1, and even if there is a small amount of base metal from the joint member 2, there is a sufficient amount of base metal to obtain a good joint surface. Discharged. Further, the base metal (burr) discharged during the friction welding corresponds to a higher margin (shrinkage allowance), but in this embodiment, as can be seen from FIG. 3, the mother metal discharged from the joining member 2 side. The amount of material metal (burrs) is small. In other words, the shrinkage allowance in the friction welding of the joining member 2 can be reduced. This means that even if the shrinkage allowance of one joining member is small, friction welding can be performed at a high temperature and high pressure necessary to obtain a good joining surface.

  Moreover, since the joining part of the joining member 1 can be easily heated to a high temperature in the frictional heat generation step, it is suitable for obtaining a good joining surface.

  After the upset process is completed, a cutting process is performed as shown in FIG. In the cutting process, the outer periphery of the joint is cut to a thickness t5 that is approximately the thickness t3 of the recess 3 including the region where the recess 3 is formed, and the cutting portion 5 is obtained. Further, deburring is performed on the inner peripheral side of the joining members 1 and 2. FIG. 5 shows a schematic diagram of a cross section of the joint in the cut portion 5. 5A shows V- (a) in FIG. 4, and FIG. 5B shows V- (b) in FIG. According to the experiments by the present inventors, it has been confirmed that a good joint surface 6 can be obtained as shown in FIG.

  Since the portion to be finally removed by cutting is provided in the joint portion of the joining member, the friction welding is performed (the joining members having a thickness larger than the thickness of the final joining portion shown in FIG. Therefore, defects resulting from the insufficient pressure generated on the outer periphery of the joint portion are not left on the outer periphery of the final joint portion, and a good joint state is obtained over the entire joint surface 6.

  Moreover, as shown in FIG. 5, according to the friction welding method of a present Example, the joint surface 6 is formed diagonally. In general, the strength of the friction welded joint is higher than that of the base metal, but in this embodiment, the joining surface 6 is formed obliquely (the outer peripheral side is closer to the joining member 1 and the inner peripheral side is closer to the joining member 2). Since the area of the strong portion is increased by forming the slanted portion in such a manner, the strength of the joined body obtained by joining the joining members can be increased.

  Next, the case where the friction welding method of the present invention is applied to the manufacture of a high-pressure sensor will be described with reference to FIGS.

FIG. 9 shows an example of a friction welding apparatus used when the friction welding method of this embodiment is carried out. FIG. 9 is a diagram illustrating a schematic configuration of the friction welding apparatus.
The friction welding apparatus moves the joining member rotating motor 10, the joining member pressing motor (or air cylinder) 20, the joining member supporting arm 30, the joining member fixing jig 40, and the joining member fixing jig in the xy directions. The work table 50 and the joining member holding portion 60 are roughly configured. A control device (not shown) for driving and controlling these devices is provided. In this embodiment, the bonding member 1 is held by the bonding member holding portion 60, and the bonding member 2 is held by the bonding member fixing jig 40. In this embodiment, rotational force and pressure are applied to the joining member 1, but only the rotational force is applied to the joining member 1, and the device configuration is changed so that the joining member 2 applies pressure. May be.

  As shown in FIG. 6, the high-pressure sensor is formed by friction welding the joining member 1 serving as a pressure guiding tube and the joining member 2 serving as a diaphragm. In this embodiment, SUS630 is used as the pressure guiding tube and the diaphragm. The pressure guiding tube and the diaphragm are formed in a predetermined shape as a high pressure sensor, and a recess 3 is formed in the vicinity of the joint portion of the pressure guiding tube (joining member) 1. That is, in this embodiment, the contraction allowance (deformation amount) on the diaphragm (joining member) 2 side cannot be increased. Then, as in the above-described embodiment, friction welding is performed as shown in FIG. 7, and cutting is performed as shown in FIG. According to this embodiment, it is possible to reduce the amount of deformation on the diaphragm side and to realize full-surface bonding without any defects on the entire bonding surface of the friction welding portion.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... 1st joining member, 2 ... 2nd joining member, 3 ... Recessed part, 4 ... Burr, 4-1 ... 1st joining member side burr, 4-2, 2nd joining member side burrs, 5 ... cutting portion, 6 ... joining surface, 10 ... joining member rotating motor, 20 ... joining member pressing motor (or air cylinder), DESCRIPTION OF SYMBOLS 30 ... Arm for supporting a joining member, 40 ... Joining member fixing jig, 50 ... Work table, 60 ... Joining member holding | maintenance part.

Claims (4)

A friction welding method for friction welding a first joining member having an annular joint end face and a second joining member having an annular joint end face,
The first joint member having a concave portion formed annularly on the outer periphery in the vicinity of the joint end face, and the joint end face having a thickness substantially the same as the thickness of the joint end face of the first joint member Preparing a second joining member,
Friction welding the first joining member and the second joining member,
Cutting the outer periphery of the joint portion by friction welding so that the thickness of the joint portion by friction welding is thinner than the thickness at the joint end faces of the first and second joining members in the preparation stage. Friction welding method characterized by performing. The friction welding method according to claim 1,
A friction welding method, wherein rotation and pressure are applied to the first joining member to fix the second joining member. A joined body friction welded by the friction welding method according to claim 1,
The joining surfaces of the joining portions of the first joining member and the second joining member are formed obliquely so that the outer peripheral side is closer to the first joining member side and the inner peripheral side is closer to the second joining member side. A joined body characterized by being. In the joined body according to claim,
The joined body is a high-pressure sensor, the first joined body is a pressure guiding tube, and the second joined body is a diaphragm.

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