JP2016185554A - Manufacturing method of joined article by press-fit joining and joined article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a joined article by press-fit joining that prevents swelling of a joined article related to the press-fit joining and is excellent in precision, quality, and reliability, and provide the joined article.SOLUTION: A manufacturing method of a joined article comprises the steps of: heating and softening a junction of both members by primarily energizing both the members to press an insertion part into a hole of a first member with pressure applied by an upper electrode; performing press-fit joining by solid-phase diffusion by pressing the insertion part of a second member into the hole until pressure applied by a pressing part of the upper electrode when moving the upper electrode downward can be applied on the lower electrode via a color member and the first member; after stopping the primary energization, performing heat treatment by secondary energization such that both the members are secondarily energized with pressure applied by the upper electrode, and the secondary energization is stopped after heating the junction between both the members and its vicinity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a bonded product by press-fitting and a bonded product as a product obtained by the manufacturing method.

  Conventionally, as a method for preventing deformation of a metal member at the time of processing, for example, the method described in Patent Document 1, as shown in FIG. 7, suppresses variation in products after the metal members are joined together. The lower electrode 44 is held in contact with the outer peripheral surface of the arc-shaped wall by the holding member 42 so that the arc-shaped wall of the second metal member 48 does not spread outward, and the second metal member 48 is pressurized by the upper electrode 46. However, both electrodes are energized and the two metal members are joined to each other by electric resistance heat, and the holding member 42 prevents the side wall portion of the first metal member 40 from expanding outwardly and deforming during press-fitting. That's it.

  Further, in the method for joining metal members described in Patent Document 2, the position restricting ring is fixed to the inner peripheral side portion of the abutting surface of the lower end surface of the annular electrode portion, and the position restricting ring is fixed to the clutch cone. The clutch cone is centered and positioned so that the axial center B of the clutch cone is coaxial with the axial center of the gear.

  The present applicant previously disclosed a press-fit joining method in Patent Document 3. This presses the second member (cylinder) into the hole of the first member (plate), energizes (primary energization) between both members, and performs solid-phase bonding by press fitting. Heat treatment (tempering) by energization (secondary energization) is performed to ensure toughness and the like.

  Similarly, the present applicant previously disclosed a method for manufacturing a steel product in Patent Document 4. This is because when a second steel material is pressed into the hole of the first steel material by primary energization and solid phase diffusion bonding is performed, the secondary heat is rapidly heated above the A3 or A1 transformation point by resistance heat by the primary energization. Reheating by energization, and by this secondary energization, the temperature of the joint is raised or maintained at a temperature above the pearlite precipitation line in the continuous cooling transformation diagram, and then the cooling curve passes over the pearlite precipitation line, and further martensite It is cooled by passing through the transformation point. By this manufacturing method, the precipitates at the grain boundaries account for the majority of the ferrite compared to the carbides, and each of them forms a lump and precipitates at the grain boundaries in the form of a net, and the dough in the net has a martensite structure. A steel product having a structure and excellent in toughness and strength is obtained.

JP-A-2005-959 Japanese Patent No. 5234505 Japanese Patent No. 4440229 JP 2014-84504 A

  In Patent Document 1, the holding member prevents the side wall portion of the metal member from expanding outwardly, but this is affected by the degree of contact by the holding member, the strength, and the like. There is a problem of being. Further, the position restricting ring described in Patent Document 2 is fixed to the lower end surface of the annular electrode and fitted into the clutch cone, and restricts the movement in the horizontal direction, and is not suitable for the restriction in the vertical direction. .

On the other hand, the present applicant has previously filed an application (Patent Document 3) related to the press-fit joining method. In this press-fit joining method, the heat generated by the electrical resistance heat during the first energization is mainly a joint with a small contact area and a large electrical resistance, but during the secondary energization, heat is generated due to an increase in the contact area of the joint. Due to the expansion of the region, the second member itself generates heat. In other words, the electrical resistance of the second member itself is relatively large with respect to the joint portion, and the second member itself (near the joint portion) also generates heat due to resistance heat in the same manner as the joint portion.
Then, due to heat generation and softening of the second member, deformation (collapse) such as the outer diameter bulging due to the applied pressure is seen, and the second member is necessary due to softening of the joint during secondary energization, etc. There was also a problem of being pushed in. Also in the method of manufacturing a steel product according to Patent Document 4, since the heat treatment by secondary energization is performed, the same problem may occur even in the case of Patent Document 3.
The deformation of the second member has been part of the member and has not been a major problem in the past. However, in recent years, the overall length of the unit has been designed to be as short as possible by reducing the weight of the unit and components accompanying the weight reduction of the vehicle. In related parts, the shaft is designed to be short, so that the tolerance of the shaft diameter is required to the base of the shaft, and the achievement of the dimensional accuracy of the member is required.

  The present invention has been made in view of the above-mentioned problems and the like, and prevents the joining product related to press-fit joining from being crushed (bulged), and is a joined product by press-fit joining that is excellent in accuracy, quality, and reliability. An object of the present invention is to provide a manufacturing method and a bonded product.

  In order to solve the above technical problem, the present invention is a method for manufacturing a joined product in which a first member 6 in which a hole 4 is formed and a second member 8 having an insertion portion 9 are press-fitted. The first member and the second member are both made of metal, and a press-fitting allowance is provided in the insertion portion 9 of the second member 8 with respect to the hole 4 of the first member 6. The first member 6 is disposed on the upper surface portion of the lower electrode 12, while the second member 8 is held by the upper electrode 10, and the lower portion of the second member 8 is pressed below the upper electrode 10. Projecting further downward, a ring shape having an insertion hole portion at the center between the pressing portion 20 of the upper electrode 10 and the upper portion of the first member 6 or a shape in which a plurality of divided pieces are combined in a ring shape In addition, the collar member 16 that is insulative or has an insulating coating on the base material is provided, The insertion part 9 of the second member 8 inserted into the part is aligned with the hole 4 of the first member 6, and the primary electrode is energized between the two members together with the pressure applied by the upper electrode 10. The joint 9 is heated and softened, and the insertion portion 9 is press-fitted into the hole 4 of the first member 6, and applied by the pressing portion 20 of the upper electrode 10 as the upper electrode 10 is lowered. Until the pressure is applied to the lower electrode 12 through the collar member 16 and the first member 6, the insertion portion 9 of the second member 8 is press-fitted and joined to the hole 4 ( In this process, solid phase diffusion bonding is performed), and after the temporary energization is stopped, secondary energization is performed between the two members in a state accompanied by the pressure applied by the upper electrode 10, Stop secondary energization after heating nearby A structure characterized.

Here, the provision of the collar member 16 between the pressing portion 20 of the upper electrode 10 and the upper portion of the first member 6 means that the collar member 16 is attached to the pressing portion 20 or the first member For example, the collar member 16 is disposed on the upper side of the member 6.
Further, the insulating coating of the collar member 16 means that an insulating paint is applied to a base material such as metal, or an insulating material coating such as ceramic spraying is applied to the base material, or an insulating material is applied to the base material. For example, covering.

In the method for manufacturing a joined product according to the present invention, instead of the collar member 16, a covering portion 36 provided with an insulating coating is provided below the pressing portion 20 of the upper electrode 10, and the pressing portion 20 of the upper electrode 10 is used. In this configuration, the applied pressure is applied to the lower electrode 12 through the covering portion 36 and the first member 6.
Here, also with respect to the insulating coating applied to the pressing portion 20, an insulating paint is applied to the pressing portion 20, or an insulating material coating such as ceramic spraying is applied to the substrate, or an insulating material coating is applied to the pressing portion. It means to do.

  The method for manufacturing a joined product according to the present invention has a configuration in which the first member 6 and the second member 8 are both made of steel.

  The method for manufacturing a joined product according to the present invention is that the side surface portion of the second member 8 is mechanically sandwiched by the upper electrode 10 having a plurality of electrode pieces 14.

  Further, in the method for manufacturing a joined product according to the present invention, when the collar member 16 is formed in a ring shape and the collar member 16 is attached to the pressing portion 20 of each electrode piece 14 of the upper electrode 10, the collar member 16. Screw holes are provided at a plurality of locations, screws having a diameter smaller than that of the screw holes are used, and a play is provided between the two screws.

  Further, in the method for manufacturing a joined product according to the present invention, the applied pressure during the secondary energization is ½ or more, preferably 2/3 or more of the applied pressure during the primary energization, and the applied pressure during the primary energization. It is as follows.

  Moreover, the bonded article according to the present invention is manufactured by any one of the above-described methods for manufacturing a bonded article.

  According to the method for manufacturing a bonded article according to the present invention, until the applied pressure applied by the pressing portion of the upper electrode is applied to the lower electrode via the collar member and the first member, Since the insertion portion is pressed into the hole portion, press-fitting by solid-phase diffusion is performed, and then heat treatment by secondary energization is performed with pressure applied by the upper electrode. The collar member has a function of preventing the press-fitting from proceeding further after press-fitting to a predetermined depth, so that the accuracy of the press-fitting depth of the second member is enhanced. Burning color (abnormal heat generation) of the member is also prevented, the quality of the joined product is improved, and the joined product having excellent reliability can be obtained.

  According to the method for manufacturing a bonded article according to the present invention, instead of the collar member, a covering portion provided with an insulating coating is provided below the pressing portion of the upper electrode, and the pressure applied by the pressing portion of the upper electrode is covered. Since it is configured to be applied to the lower electrode via the part and the first member, the second member can be prevented from being crushed (bulging) and the press-in depth accuracy can be improved and the member can be burnt in the same manner as above. As a result, it is possible to improve the quality, to obtain a bonded product with excellent reliability, and to produce an economical effect.

  According to the method for manufacturing a joined product according to the present invention, since the first member and the second member are both made of steel, the accuracy and quality of the joined product using steel are improved, and toughness is achieved. As a result, it is possible to obtain a bonded product having excellent reliability.

  According to the method for manufacturing a joined product according to the present invention, since the side surface portion of the second member is mechanically sandwiched by the upper electrode having a plurality of electrode pieces, the second member can be quickly held and added. There is an effect that pressure can be transmitted reliably.

  Further, according to the method for manufacturing a joined product according to the present invention, when the collar member is attached to the pressing portion of each electrode piece of the upper electrode, a screw having a diameter smaller than that of the screw hole of the collar member is used. Since it has a structure that is attached with a collar member, it is possible to save time and effort such as interposing a collar member each time, and each electrode piece can be expanded and sandwiched within the range of play, and the second member can be quickly moved to the upper electrode. There is an effect that it can be attached to.

  Further, according to the method for manufacturing a joined product according to the present invention, the applied pressure at the time of secondary energization is 1/2 or more, preferably 2/3 or more of the applied pressure at the time of primary energization, and below the applied pressure at the time of primary energization. Therefore, there is an effect that the applied pressure can be appropriately adjusted according to the shape, thickness, etc. of the first member and contribute to quality assurance.

  In addition, according to the joined product according to the present invention, since it is manufactured by any one of the above-described joined product manufacturing methods, the second member can be prevented from being crushed (swelled) as described above. As a result, the quality is improved and the bonded product with excellent reliability can be obtained.

It is a figure which concerns on embodiment and shows the manufacturing apparatus (part) used for the manufacturing method of a joined article. It is a figure which shows the color member which concerns on embodiment. It is a figure which shows the upper electrode (attaching a color member) which concerns on embodiment. It is a figure which shows the upper electrode (formation | coating part) which concerns on embodiment. It is a figure which shows the electrode vicinity immediately before the primary electricity supply which concerns on press-fit joining. It is a figure which shows the electrode vicinity in the secondary electricity supply which concerns on press-fit joining. It is a figure which shows the joining apparatus which concerns on a prior art example.

Hereinafter, embodiments of the present invention will be specifically described.
FIG. 1 shows a press-fitting device 2 (part) for manufacturing a joined product by press-fitting. The joined product in which the members are joined by the press-fitting device 2 is a metal element part. Here, the product is joined to the plate body 6 (first member) provided with the hole 4 and the hole 4. The shaft body 8 (second member) was used. The plate body 6 and the shaft body 8 are both made of steel. Further, a press-fitting allowance is required as a predetermined overlapping portion between the hole 4 of the plate body 6 and the insertion portion 9 of the shaft body 8.

  The press-fitting device 2 supports a control mechanism for controlling the whole, an upper electrode 10 and a lower electrode 12 as electrodes to be energized between the plate body 6 and the shaft body 8, an upper platen 11 for holding the upper electrode 10, and a lower electrode 12. A lower platen 13, a moving mechanism for positioning and moving the upper platen 11 to a predetermined position, and a press mechanism for applying pressure to the upper platen 11 (each mechanism is not shown). The electrode has a configuration in which the electrode body is fixed to the electrode holder with a bolt or the like.

The upper electrode 10 is configured to hold (clamp) the shaft body 8, and the lower electrode 12 is a thick plate with a flat surface on which the plate body 6 can be placed, both of which are electrodes (electrode bodies). The material is made of chromium copper or beryllium copper.
Here, the upper electrode 10 is divided into four electrode pieces 14 (a shape that is combined in a ring shape for holding the shaft body 8), and the so-called shaft body 8 is held by a holding portion below each electrode piece 14. A collet chuck type electrode was used. In addition, the upper electrode 10 may be divided into a plurality of electrode pieces, and these electrode pieces are combined in a ring shape.
The upper electrode 10 and the lower electrode 12 are energized through the upper platen 11 and the lower platen 13, respectively. As a power source used for energization, direct current, alternating current, or direct current using a large-capacity capacitor can be used.

  Further, in this embodiment, an insulating collar member 16 is provided between the upper electrode 10 that holds and pressurizes the shaft body 8 and the plate body 6, and the pressure applied to the shaft body 8 by the collar member 16 is reduced. Adopted a strategy to do. The collar member 16 insulates between the upper electrode 10 and the plate body 6 and receives pressure applied between them. As a form in which the collar member 16 is provided (intervened), there is a form in which the collar member 16 is disposed on the lower electrode 12 or fixed to the lower part of the upper electrode 10.

  Here, as the collar member 16, as shown in FIG. 2A, a ring-shaped (hollow disk-shaped) insulating material having an insertion hole 22 at the center is used. The size of the insertion hole portion 22 is appropriate such that the shaft body 8 (insertion portion 9) can be inserted slowly. The gap between the shaft body 8 and the insertion hole 22 is 0.5 mm or more and 3 mm or less (radial direction) with respect to the shaft body 8, more preferably 1 mm or more and 2 mm or less. The plate thickness of the collar member 16 is preferably set to a size necessary for securing a heat storage region 24 of the shaft body 8 to be described later. Besides, the strength of the collar member 16 and the electrical resistance of the shaft body 8 itself, etc. Is considered to be 0.5 mm or more and 5 mm or less, more preferably 1 mm or more and 3 mm or less.

  For example, when the collar member 16 is thin, as a method of securing a larger amount of the heat storage region 24, for example, there is a method of providing a concave portion (chamfering) around the inside (nipping portion side) of the tip portion of the upper electrode 10 itself. . According to the upper electrode 10, the exposed portion 23 that is not in contact with the upper electrode 10 is formed in the shaft body 8 by the concave portion, and this can be secured as the heat storage region 24.

Further, as the collar member 16, a plurality of divided pieces (insulating), for example, a shape in which a plurality of arc-shaped pieces are combined in a ring shape can be used.
FIG. 2 (b) shows an insulating member having two insulating arc-shaped segment pieces 17, 17 combined in a ring shape and having an insertion hole 22 at the center as the collar member 16.
As described above, the use of the collar member 16 divided into a plurality of divided pieces is particularly effective when the shaft body 8 has a shape in which an enlarged diameter portion is provided on the upper portion. That is, when the collar member 16 has a ring shape (integrated), the collar member may not be removed from the joined product after joining. When the collar member 16 is constituted by a plurality of divided pieces, it is preferable to arrange the divided pieces in combination so that the whole is ring-shaped. Also in the form in which the collar member 16 is arranged in a ring shape with a plurality of divided pieces, the gap between the shaft body 8 and the plate thickness of each divided piece are the same as in the case of the ring-shaped collar member 16. .

As the material of the color member 16, it is possible to use a heat-insulating ceramic, a synthetic resin such as a bakelite and a fluororesin.
In addition, as the color member 16, it is also possible to use a material in which a base material is coated with an insulating coating, such as coating a metal material as a base material with a heat-resistant insulating paint, or coating a metal material with a heat-resistant insulating material. Is possible. More specifically, as the color member 16, it is possible to adopt an insulating paint coated product obtained by applying a heat-resistant insulating paint to chrome copper or the like, a ceramic coated product obtained by applying an insulating ceramic spray to chrome copper or the like. In addition, it is possible to use a base material coated with a heat-resistant insulating material (synthetic resin or the like) and provided with an insulating coating.

In addition, it is also effective to use a spring washer (a disc spring, a coil spring, etc.) for the base material of the collar member 16. In this case as well, an insulating coating is applied to the surface of the spring washer, and this is used as the collar member 16.
In the case where the pressing portion 20 of the upper electrode 10 or the upper portion of the plate body 6 is not flat, etc., the contact portion between the collar member 16 and the pressing portion 20 or the like may cause contact, and a gap may be generated. In this case, by using the collar member 16 using a spring washer as a base material, the above-mentioned piece contact can be prevented.
Further, as the color member 16, it is possible to use the above-mentioned insulating coating applied to one side or both sides of the base material. Since the collar member 16 is located near the joint 18 between the plate body 6 and the shaft body and is exposed to a high temperature, heat resistance and pressure resistance are required, and durability associated with mass production is also required.

Here, a material (ceramic coated product) obtained by subjecting chromium copper to ceramic spraying was used as the collar member 16. This is a hollow disk material made of chrome copper having a thickness of 2 mm and subjected to a ceramic spraying treatment with a thickness of 0.6 mm on both sides for finishing (insulation coating). The collar member 16 has a ring shape (outer diameter φ = 25 mm, inner diameter φ = 18 mm, shaft diameter φ = 12 mm) with a plate thickness of 3 mm.
Ceramic sprayed material has high hardness, high adhesion between particles, high density and smooth insulation coating regardless of the material of the base material, and can withstand use at high temperatures without cracking. .

The plate body 6 has a predetermined thickness, and the hole 4 provided in the plate body 6 has a circular shape with a constant cross-sectional diameter, and the inner wall of the hole 4 is perpendicular to the plate surface of the plate body 6. A surface portion is formed.
As the plate body 6, a relatively flat metal element part such as a plate-shaped material, a disk-shaped material, a dish-shaped material, a gear, or a sprocket can be used. In addition, instead of the plate body 6, it is also possible to use members (various lump shapes such as a rectangular parallelepiped) in which the hole portions 4 are formed in the vertical direction.
In addition, here, a concave burr storage part (sink) is provided around the upper inner peripheral side of the hole 4 of the plate body 6 to store a burr (remaining wall) generated at the time of press-fitting.

The shaft body 8 is columnar (or cylindrical). The insertion portion 9 of the shaft body 8 is a portion formed in the lower portion of the shaft body 8 and having a uniform diameter, and is a portion that is press-fitted into the hole 4 of the plate body 6.
The outer diameter (diameter) of the insertion portion 9 of the shaft body 8 is slightly larger than the diameter of the hole 4 of the plate body 6, and the press-fitting allowance is the difference between them. Due to this press-fitting allowance, the outer peripheral portion of the insertion portion 9 of the shaft body 8 is rubbed in contact with the inner wall surface of the hole 4 of the plate body 6 to form a joining interface, and press-fit joining is performed over the entire circumference.
In addition, as the second member (shaft body 8), an insertion portion 9 having a solid material, a hollow material, a bar material, a pipe shape or the like is used.

Here, the hole 4 of the plate body 6 is circular and the cross section of the shaft body 8 is circular. However, the shape of the hole 4 and the shaft body 8 (insertion portion 9) is polygonal or semicircular. It can be applied to an oval shape or the like.
Further, the shaft body 8 (insertion portion 9) has a shape in which the entire circumference is joined when the cross section of the hole portion 4 is similar to the shape of the hole 4, but the shaft body 8 that does not have a similar shape is employed. Even the surrounding partial joining is possible. In any case, a press-fitting allowance is required between the hole 4 and the shaft body 8 (entire circumference or part).

The upper electrode 10 has a shape having four electrode pieces 14 as shown in FIG. Each electrode piece 14 has a configuration in which four electrode bodies 15 are respectively fixed to the lower part of the electrode holder with bolts or the like.
The upper electrode 10 mechanically clamps the shaft body 8 from the four sides by the electrode pieces 14. The clamping force of the electrode piece 14 itself can be obtained by an air cylinder mechanism, a spring mechanism, a screw type, or the like. A sandwiching portion that sandwiches the side surface portion of the shaft body 8 is formed below the electrode piece 14.
Moreover, the lower surface of each electrode piece 14 is flat, and this part (electrode main body 15) functions as the pressing part 20.
In addition, although the shaft body 8 is clamped using the electrode piece 14 (electrode main body 15) which consists of 4 pieces here, this is a form which has several electrode pieces, such as 2 pieces, 3 pieces of electrode pieces, etc. It can be.
In addition, as the upper electrode 10, it is possible to use an electrode in a fitting form having a hole portion into which the upper portion of the shaft body 8 is fitted.

  The upper electrode 10 is mounted on the moving mechanism via the upper platen 11, and the shaft body 8 is mechanically held by the upper electrode 10 and is transported to a predetermined position and positioned by the moving mechanism. . When the shaft body 8 is press-fitted, the upper electrode 10 can be lowered by the vertical movement function of the moving mechanism, and the upper electrode 10 is pressed by the pressing force of the pressing mechanism, and the shaft body 8 is lowered with the pressing force. Let

In the case where the collar member 16 is interposed between the upper electrode 10 and the plate body 6, in consideration of the form arranged on the upper portion of the plate body 6, productivity, etc., the pressing portion 20 below the upper electrode 10 is colored. There are forms for attaching the member 16 (engagement, screwing, adhesion, etc.).
When the collar member 16 is attached, for example, a method of screwing the collar member 16 to the lower part of the upper electrode 10 using screws or the like, a method of attaching a bolt shaft to the upper part of the collar member 16 and screwing it to the lower part of the upper electrode 10, etc. There is. It is also possible to provide collars on both sides of the collar member 16 and engage the collars with locking grooves provided in the lower part of the upper electrode 10.

Here, a mode is shown in which screw holes 32 are provided at four locations (corresponding to each electrode piece) of the ring-shaped collar member 16, and the collar member 16 is attached to the lower pressing portion 20 of the upper electrode 10 using screws 34. It was. In this case, the diameter (outer diameter) of the screw 34 is made smaller than the diameter (inner diameter) of the screw hole 32 so that a gap (horizontal direction) is formed between the screw hole 32 and the screw 34. Then, a screw hole is provided in the pressing portion 20, and the collar member 16 is screwed using a screw 34. Thus, when the collar member 16 is attached to the lower part of the upper electrode 10, a play is provided between them.
Then, when the shaft body 8 is sandwiched between the electrode pieces 14 of the upper electrode 10, the shaft body 8 is inserted by slightly opening the inner diameter of the sandwiching hole portion surrounded by the four electrode pieces 14 (expansion) before clamping. Thereafter, the clamping hole is closed and the shaft body 8 is clamped. As described above, if a gap is provided between the screw 34 and the screw hole 32 and the gap is formed within a range in which the shaft body 8 can be inserted, the shaft body is opened and closed by opening and closing the electrode pieces corresponding to the gap. 8 can be freely attached and detached.

  When the upper electrode 10 has a plurality of electrode pieces, a collar member 16 made up of a plurality of arc-shaped pieces may be used. For example, when the upper electrode 10 has two electrode pieces 14, 14, a collar member 16 composed of two arc-shaped pieces (divided pieces 17, 17) is used for each of the arc-shaped pieces. , 14 is attached to the pressing portion 20 below.

Moreover, it can replace with the collar member 16 and the form which provides insulation coating to the press part 20 of the lower part of the upper electrode 10 is employable.
As shown in FIG. 4, a covering portion 36 provided with an insulating coating is provided on the lower portion of the pressing portion 20 of the upper electrode 10. In this case, the pressure applied by the pressing portion 20 of the upper electrode 10 is applied to the lower electrode 12 through the covering portion 36 and the plate body 6.
The insulating coating applied to the upper electrode 10 includes a form in which a heat-resistant insulating paint is applied to the pressing portion 20, a form in which, for example, ceramic spraying is applied as an insulating material coating, or a form in which a heat-resistant insulating synthetic resin is coated. In this case, since it is not necessary to separate the electrode and the collar member, it is simple and economical.

When the shaft body 8 is sandwiched by the upper electrode 10, the length of the shaft body 8 that protrudes downward from the pressing portion 20 of the upper electrode 10 that sandwiches the shaft body 8 is determined by the size of the press-fitting depth and the interposition collar member 16. It is necessary to make it equal to the length obtained by adding the thickness dimension. The dimension of the press-fit depth is a depth at which the insertion portion 9 is inserted from the surface of the plate body 6.
For example, when the press-fitting depth is 4 mm and the thickness of the collar member 16 is 3 mm, the lower portion (insertion portion 9) of the shaft body 8 is sandwiched with 7 mm (4 + 3 mm) protruding from the pressing portion 20 of the upper electrode 10.

  At this time, when press-fitting is completed with a press-fitting depth of 4 mm, the upper electrode 10 (pressing portion 20), the collar member 16, the plate body 6, and the lower electrode 12 (surface) are overlapped and in close contact with each other. Then, during the secondary energization, the applied pressure applied by the upper electrode 10 to the shaft body 8 is switched from the shaft body 8 to the collar member 16, and the applied pressure by the upper electrode 10 is received by the collar member 16. The applied pressure is not applied to the shaft body 8. This is the main function of the collar member 16.

Here, press-fit joining will be described. FIG. 5 shows the vicinity of the electrodes of the press-fitting device. The upper electrode 10 sandwiches the side surface portion 19 of the shaft body 8, and the plate body 6 is placed on the lower electrode 12. Here, the color member 16 is arranged on the upper side (surface) of the plate body 6.
The lower electrode 12 has a flat upper surface portion 26 on which the plate body 6 is placed and supported, and a hole portion 28 having a circular cross section is provided near the center of the upper surface portion 26. The plate body 6 has its hole portion 4 arranged at the upper portion of the hole portion 28 with its center substantially coincided.
The size of the hole 28 (D: inner diameter) is slightly larger than that of the shaft body 8. This hole portion 28 is used to form the clearance because the periphery of the hole 4 of the plate body 6 is deformed in the press-fitting direction when the shaft body 8 is press-fitted and joined to the plate body 6. The size (D) of the hole 28 is preferably slightly larger than the inner diameter (D1) of the hole 4 of the plate body 6.

The hole portion 28 prevents sparks, explosions, and the like generated at the contact portion when the contact between the plate body 6 and the lower electrode 12 becomes unstable due to the load applied to the plate body 6.
In addition, as a utilization form of the hole portion 28, a positioning member that can be moved up and down by a coil spring can be disposed in the hole portion 28. This positioning member is formed so as to be able to be engaged and inserted into the hole 4 of the plate body 6, can be used for positioning the plate body 6 and the collar member 16, and elastically moves downward as the shaft body 8 is press-fitted.

The outer diameter (D2: diameter) of the insertion portion 9 of the shaft body 8 is slightly larger than the inner diameter of the hole 4 of the plate body 6, and the press-fitting allowance is the difference between these. Further, chamfering is performed on one or both of the upper edge of the hole 4 of the plate body 6 and the edge of the lower surface of the shaft body 8 to provide a chamfer 29.
As conditions for press-fitting joining, a press-fitting allowance (d) between the hole 4 of the plate body 6 and the shaft body 8 and a press-fitting depth (h) are set.

The press-fitting allowance (d) is relative to the diameter. Here, the press-fitting allowance (d) = the outer diameter (D2) of the shaft body 8−the inner diameter (D1) of the hole portion 4. The press-fitting allowance may be in a range where press-fitting is possible. The range of the press-fitting allowance is practically 0.1 mm to 0.7 mm, but if it is in the range of 0.1 mm to 0.5 mm, there are few burrs and it is good.
The press-fitting depth (or the plate thickness of the plate body 6) depends on the magnitude of the energization current, but a range of 1 mm to 10 mm, preferably 1 mm to 6 mm is practical and good. The press-fitting depth (h) is h = depth of press-fitting (insertion from the surface of the plate body 6) of the insertion portion 9 of the shaft body 8 (here, the same as the plate thickness of the plate body 6).

  The collar member 16 is interposed between the pressing portion 20 of the upper electrode 10 and the plate body 6. The collar member 16 insulates between the pressing portion 20 of the upper electrode 10 and the plate body 6, stops the lowering of the upper electrode 10, receives the applied pressure, and the applied pressure of the upper electrode 10 is applied to the shaft body 8. Do not. The collar member 16 is required to have a material, a shape, and the like that are insulated from the upper electrode 10 and the plate body 6 and can withstand the pressure applied between them.

Here, based on FIG.5 and FIG.6, the manufacturing method of a press-fit joining article is demonstrated. As a manufacturing process, first, the plate body 6 is placed on the upper surface portion 26 of the lower electrode 12. At this time, the positioning is performed so that the center of the hole 4 of the plate body 6 is positioned at the center of the hole 28 of the lower electrode 12.
On the other hand, the shaft 8 is held by the lower electrode 12. The shaft body 8 is mechanically held by the electrode pieces 14 and 14 of the lower electrode 12.
Further, in this embodiment, the collar member 16 is arranged on the upper portion of the plate body 6 so that the centers of both the hole portions coincide with each other.

Next, the shaft body 8 is moved to a predetermined positioning position together with the upper electrode 10 by the moving mechanism. Then, the upper electrode 10 is lowered together with the pressure applied by the press mechanism, and the tip of the insertion portion 9 of the shaft body 8 is aligned with the hole 4 of the plate body 6 (the matching accuracy is increased by the chamfered portion 29). At this time, the shaft body 8 is maintained in a state with a constant pressure against the hole 4 of the plate body 6 by the press mechanism.
Then, power is supplied according to an instruction from the control mechanism or the like, and energization by primary energization is started between the upper electrode 10 and the lower electrode 12. As a result, a large-capacity current flows between the shaft body 8 and the hole 4 of the plate body 6 (joint portion 18), and the joint portion 18 softens as the electric resistance heat is generated, and press-fitting of the shaft body 8 is started. The insertion portion 9 of the shaft body 8 moves down in the hole 4 of the plate body 6.

In this case, the shaft body 8 is press-fitted into the hole 4 of the plate body 6, and at this time, the ironing action occurs at the joint interface between the two members, and the press-fit joining is performed. As a result, the surface oxide layer and the like are scraped to clean the surface, and solid phase diffusion bonding (solid phase diffusion bonding) is performed on this clean tissue.
The press-fitting proceeds, and the pressing portion 20 of the upper electrode 10 comes into contact with the collar member 16 and the upper electrode 10 presses the collar member 16, the plate body 6 and the lower electrode 12. At this time, the lowering of the upper electrode 10 is prevented, the progress of press-fitting is stopped, and the solid phase diffusion bonding of the shaft body 8 to the plate body 6 is completed. Further, the pressure applied to the shaft body 8 by the upper electrode 10 is switched to the pressure applied to the lower electrode 12 through the collar member 16 and the plate body 6.

Then, primary energization is stopped by an instruction from the control mechanism or the like. The energization time from the start of primary energization to the stop of energization is set slightly longer than the time until the press-fitting of the shaft body 8 to the hole 4 of the plate body 6 is completed.
In the press-fitting method, the press-fitting by pressurization and energization described above is performed, the joint 18 is instantaneously heated, and the shaft body 8 is press-fitted into the hole 4 in a short time to complete the joining. Stop energization after heating and press-fitting by primary energization.
As a waiting time (cooling period) from the stop of primary energization to the start time of secondary energization, 0.1 second to 2 seconds is secured in consideration of heat treatment by secondary energization. If the waiting time is too short, the vicinity of the joint is excessively heated during secondary energization, which is not preferable.

Next, heat treatment is performed by secondary energization, and along with the description of the process of secondary energization, here, verification of pressurization and energization related to press-fit bonding, especially secondary energization, etc. was performed, and the present invention was found. Add a description of the background. The heat treatment by secondary energization here is mainly performed in order to obtain a structure rich in toughness and strength in the joint portion 18 between the plate body and the shaft body made of steel.
When press-fit joining is started under the above-described press-fit joining conditions, the shaft body 8 hits the hole 4 of the plate body 6 that is a joining member, and the movement stops, but pressure remains applied to the contact portion. The pressure applied by the upper electrode 10 as a press-fit joining condition at this time depends on the diameter of the shaft body 8 (the diameter of the hole 4 of the plate body 6). For example, when the diameter (φ) is 12 mm, 500 ~ 600kgf is required.

When primary energization is started in this state and electricity flows from the upper electrode 10 to the lower electrode 12, the portion having the smallest cross-sectional area in the current path, that is, the joint portion 18 having the highest electrical resistance generates the most heat.
Then, the press-fitting and energization start, the press-fitting proceeds, and the cross-sectional area of the joint 18 increases accordingly. As the cross-sectional area increases, the electrical resistance of the joint 18 decreases and the amount of heat generation also decreases.
At this point, a slight change (bulge) is seen in the upper part of the shaft body 8 near the joint 18. This is due to the pressure applied to the shaft body 8 from the upper electrode 10 and the heat generation around the shaft body 8, and the diameter of the shaft body 8 swells by about several μm.

Secondary energization is performed with the press-fit joining completed. In order to perform heat treatment satisfactorily by secondary energization, the applied pressure at the time of secondary energization is reduced from that at the time of primary energization. For example, at the time of secondary energization, the applied pressure by the upper electrode 10 is the same as that at the time of primary energization. About 2/3. If secondary energization is performed with the same pressure without reducing the pressure, the joint 18 is displaced or the shaft body 8 is crushed (swelled), and the shaft body 8 is unnecessarily large. Pushed in.
However, if the applied pressure is reduced too much during secondary energization, discharge and spark are generated at the contact portion between the electrode (particularly the lower electrode 12) and the plate body 6. This is because the contact degree between the back surface of the plate body 6 and the lower electrode 12 is weakened, so that the contact between the electrode and the plate body 6 becomes unstable (high electrical resistance), and the discharge phenomenon. This is because.

In short, the pressurization by the upper electrode 10 at the time of the secondary energization is not for (adding) to the joint portion 18 between the shaft body 8 and the plate body 6, but the contact portion between the plate body 6 and the lower electrode 12. This is performed in order to increase the degree of adhesion.
Further, the heat generation part during the secondary energization is different from the heat generation part in the press-fitting joining process concentrated on the joint 18, and the shaft body 8 is located above the joint 18 and in addition to the joint 18. A portion that protrudes downward from the electrode 10 and is exposed generates heat.

It is effective to heat the exposed portion of the shaft body 8 in the vicinity of the joint portion 18 in addition to the heat generation of the joint portion 18 by secondary energization. That is, the exposed portion is in the vicinity of the joint portion 18 of the joint portion 18 material, and the exposed portion 23 is used as a heat storage region 24 that generates heat and retains this heat. The cooling rate in the vicinity of the portion 18 can be made moderate. For this reason, the presence or absence of the exposed portion of the shaft body 8 affects the cooling rate, and also affects the effects of heat treatment (toughness, bonding strength, etc.).
Conventionally, the exposed portion 23 of the shaft body 8 may cause a defective phenomenon such as a slight deformation such as being crushed by an applied pressure and heat generation during secondary energization and an outer diameter expanding. In addition, at the time of primary energization and particularly at the time of secondary energization, the shaft 18 is pushed deeper due to the softening of the joint 18 and its vicinity due to heat generation, and the press-fit depth may increase beyond the specified level.

For this reason, as a result of testing the cause of the expansion of the outer diameter of the exposed portion 23 of the shaft body 8, the present inventors have come to include pressure and softening due to heat generation of the shaft body 8.
On the other hand, means such as lowering the current value at the time of secondary energization or lowering the pressurizing force can be considered, but taking such a means is not preferable for maintaining the quality of the product (joined product). . In particular, the reduced pressure with a significant applied pressure may cause discharge and spark between the plate body 6 and the lower electrode. Further, in order to maintain the accuracy of the press-fitting depth, there is a method of providing a step portion on the shaft body and causing it to function as a stopper.

Therefore, in view of the above matters, the present inventors have found a technique for releasing the applied pressure to the plate body 6 and the like so that the applied pressure by the electrodes is not applied to the shaft body 8.
In this technique, a collar member 16 is newly adopted, and is arranged so that the pressure applied by the upper electrode 10 is applied to the lower electrode 12 through the plate member 6 through the collar member 16 during press-fitting energization (secondary energization). The collar member 16 prevents the pressure applied when the secondary energization is applied directly to the shaft body 8 and prevents the outer diameter of the shaft body 8 that has been heated and softened by the energization from expanding.

As described above, the present inventors have devised interposing the collar member 16 between the upper electrode 10 and the plate body 6 relating to the joining member. The interposition of the collar member 16 is possible even immediately before the start of secondary energization, but it is effective in the manufacturing process that the primary energization or permanent installation is performed.
Then, during secondary energization, the pressing portion 20 provided at the lower end of the upper electrode 10 presses the plate body 6 through the collar member 16. Thereby, the pressure applied by the upper electrode 10 applied through the shaft body 8 is diverted from the pressing portion 20 of the upper electrode 10 to the plate body 6 and the lower electrode 12 via the collar member 16.
For this reason, the pressure applied to the shaft body 8 is theoretically zero, and the exposed portion 23 of the shaft body 8 is not crushed and the outer diameter of the shaft body 8 does not bulge. Further, the pressure applied by the upper electrode 10 is directly transmitted to the plate body 6 and the lower electrode 12 through the collar member 16, and effectively presses the contact portion between each other, particularly the contact portion between the plate body 6 and the lower electrode 12.

Furthermore, by interposing the collar member 16, the corresponding portion of the shaft body 8 is exposed by the plate thickness of the collar member 16. Heating with resistance heat is performed.
By heating the exposed portion 23 of the shaft body 8, this functions as the heat storage region 24, and the heat storage region in the vicinity of the joint portion 18 between the plate body 6 and the shaft body 8 is expanded. The speed of cooling of the joint 18 between the shaft body 8 and the shaft body 8 (including the cooling of the heat storage region 24) is reduced, and the speed can be controlled.

By the interposition of the collar member 16, the heat storage area 24 (the thickness of the collar member 16) can be effectively secured. Note that if the heat storage area 24 is small, the heat of the joint 18 easily escapes to the upper electrode 10.
When cooling a heated steel material, the structure of the corresponding part of the steel material transforms to martensite if it is rapidly cooled. As a result, a large amount of precipitates are deposited, thereby ensuring toughness and the like and increasing the strength.

  Further, the press-fitting depth during press-fitting is accurately controlled by the collar member 16 due to the interposition of the collar member 16. For this reason, inconvenience that the depth of press-fitting proceeds unscheduled at the time of joining by temporary energization and heat treatment by secondary energization is prevented, and the accuracy of the press-fitting depth is ensured, which is preferable. Conventionally, the control of the press-in depth has been performed mainly by controlling the joining conditions such as the energization time, current value, and applied pressure of the primary energization, and by product specifications such as providing a step in the member.

  After the press-fit joining by primary energization is completed, under the condition that the pressing portion 20 of the upper electrode 10 hits the collar member 16, the pressing force by the upper electrode 10 is applied to the plate body 6 and the lower electrode 12 through the collar member 16. As a result, the pressure applied by the upper electrode 10 is switched from the pressure applied through the shaft body 8 to the pressure applied via the collar member 16 (F), and the pressure applied by the upper electrode 10, the collar member 16, the plate body 6, and It is transmitted to the lower electrode 12. Therefore, at the time of secondary energization after press-fit joining, the pressure applied to the shaft body 8 is theoretically zero, and the exposed portion 23 (heat storage region 24) of the shaft body 8 is not crushed (bulged).

That is, at the time of press-fitting by primary energization, the joint 18 between the plate body 6 and the shaft body 8 is heated and softened, and the insertion portion 9 is press-fitted into the hole 4. The insertion portion 9 of the shaft body 8 is press-fitted into the hole portion 4 until the pressure applied by the pressing portion 20 is applied to the lower electrode 12 via the collar member 16 and the plate body 6. Press-fitting by diffusion is performed. In this state, the applied pressure applied to the shaft body 8 by the upper electrode 10 bypasses the collar member 16 and the like, and the shaft body 8 is released from the applied pressure.
Then, after the press-fit joining, secondary energization is performed between the plate body 6 and the shaft body 8 in a state where a predetermined pressure is held by the upper electrode 10, and the joint portion 18 and the vicinity thereof (shaft body 8). In the heat storage region 24), heat is generated by generating electric resistance heat, and then the secondary energization is stopped, and the joint 18 and the like are cooled (slowly cooled) to perform heat treatment.
After the secondary energization is stopped, the joined product is removed from the electrode at the optimum timing for the joined product. Usually this timing is within 5 seconds.

Here, a test for verifying the amount of change in the diameter of the shaft body 8 (collapse due to bulging) was performed using a press-fitting device based on the above-described press-fitting process, and the results will be described.
For comparison, a test not using “color member 16” (“test (1)”) and a test using “color member 16” (“test (2)”) were performed for comparison.

Each test condition of test (1) and test (2) is as follows.
Plate body Thickness: 3.2mm Hole diameter: 11.6mm Material: SPHC + carburizing and quenching Shaft body Outer diameter: 12.0mm Material: Carbon steel (S35C) Press-fit allowance 0.4mm
Color material Thickness: 3mm (however, only test (2) is used)
Primary energization Current value: 20 kA Energization time: 0.25 seconds Applied pressure: 500 kgf
Secondary energization Current value: 15 kA, energization time: 0.17 seconds Applied pressure: 300 kgf
After the primary energization is stopped, there is a little waiting time between the start of secondary energization. Also, the joined product is removed from the electrode after the secondary energization is stopped.

The test was performed seven times (n = 1 to 7) using seven sets of materials (plate body 6 and shaft body 8), and the same test was performed to obtain an average value.
In the test (1), press-fitting by primary energization and secondary energization were performed along with pressurization.
In the test (2), the collar member 16 was disposed on the upper side of the plate body 6, and press-fitting and primary energization by primary energization were performed along with pressurization.

Result of test (1)

In Table 1, “Before joining” indicates the diameter (diameter) of the shaft body 8 before joining, “After joining (without secondary energization)” indicates the diameter of the shaft body 8 after joining by primary energization, and “Secondary energization”. “After” indicates the diameter of the shaft body 8 after heat treatment by secondary energization.
Here, the position at which the diameter of the shaft body 8 was measured was a portion slightly above (0.5 mm to 1.0 mm above) from the root of the shaft body 8 (after joining). This measurement location is a position for confirming the accuracy required for a product (joined product) (a position where a conventional bulge has been seen). The following table is the same.

From the results of the test (1) (Table 1), almost the same results are obtained for any of the tests. Here, these average values are compared and examined. When viewed as an average value (n = 7), the amount of change of the shaft body 8 after the primary energization related to joining (diameter after joining−diameter before joining) is about 3 μm (11.955-11.952 mm).
Furthermore, the amount of change after secondary energization for heat treatment (diameter after secondary energization−diameter before joining) is 170 μm (12.125-11.952 mm). Thus, after the secondary energization, the amount of change (the amount of bulging) in the vicinity of the root of the shaft body 8 is large and the variation is large.

Result of test (2)

From the results of the test (2) (Table 2), almost the same results are obtained for any of the tests, but these average values are compared and examined. When viewed with an average value (n = 7), the amount of change of the shaft body 8 after the primary energization for joining (diameter after joining-diameter before joining) is about 1 μm (11.954-11.953 mm). It can be said that there is almost no change. In addition, the effect of the “color member 16” appears even when compared with the result of test (1) (change amount 3 μm). Further, the change amount after secondary energization (diameter-joint after secondary energization) The previous diameter is 1 μm (11.954-11.953 mm). This result is the same as the amount of change after primary energization, and it can be said that there is no change in the amount of change due to secondary energization.
From these results, it was confirmed that by interposing the collar member 16 between the lower electrode 12 and the plate body 6, deformation of the shaft body 8 due to secondary energization (collapse due to bulging) can be reliably prevented.

Here, since the test (3) was performed in an attempt, the test conditions and test results will be described.
Test conditions for test (3) are all the same as for test (2) except that the applied pressure during secondary energization is 500 kgf (same as during primary energization). Conventionally, the pressure was reduced during secondary energization to prevent crushing, but here we applied the same pressure as the primary energization to perform secondary energization and see the results. did.

From the results of test (3), substantially the same results were obtained for any of the five tests. When viewed as an average value (n = 5), the average value of the diameter of the shaft body 8 after the secondary energization is φ = 11.955 mm, which is the same result as in the test (2). The amount of change of 8 (collapse due to bulging) is a value that can be said to be almost unchanged.
The only change that was observed was the color of burnt color (color unevenness generated on the surface of the steel material due to heating) at the contact portion with the lower electrode 12 on the back surface of the plate body 6.
The back surface of the plate body 6 according to the test (1) was changed to a burnt color and was seen to be eroded by heat, but the occurrence of a burnt color was observed on the back surface of the plate body 6 according to the test (3). It is not seen, and the surface is hardly eroded by heat.

  The phenomenon of the test (3) is that, as a result of increasing the applied pressure during secondary energization in the same manner as during temporary energization, the degree of adhesion between the back surface portion of the plate body 6 and the lower electrode 12 (upper surface portion) is improved. This is thought to be the result of a decrease in the area of abnormal heat generation. That is, the contact portion between the lower electrode 12 and the plate body 6 is an aggregate in a state where many points are contacted microscopically, and when a large current is passed in this state, the area around the contact point generates heat. On the other hand, a discharge phenomenon occurs in a non-contact portion. Due to the abnormal heat generation of the discharge phenomenon, the back surface portion of the plate body 6 (and the surface portion of the lower electrode 12) is eroded on each surface and a lot of burnt colors are generated. In this case, the lower electrode 12 is also eroded and worn and the life is shortened.

Further, in the test (2) using the collar member 16, the back surface portion of the plate body 6 is the same as in the test (3), although the pressing force at the time of secondary energization is as low as 300 kgf as compared with the test (3). No burnt color is seen.
In the test (1), since the shaft body 8 held by the upper electrode 10 is intensively pressed only in the vicinity of the hole 4 of the plate body 6, warping occurs around the periphery of the plate body, This warpage hinders the adhesion with the lower electrode 12, and as a result, discharge or the like occurs, and a burnt color is generated on the back surface of the plate body 6 and the like.
On the other hand, in the test (2), the pressure force of the upper electrode 10 is directly applied to the collar member 16, and the plate body 6 is pressed by the entire collar member 16, that is, the wide surface. Therefore, the adhesiveness between the plate body 6 and the lower electrode 12 is maintained, and therefore the burnt color does not occur on the back surface of the plate body 6 and the like.

In other words, the use of the collar member 16 makes it possible to increase the applied pressure during secondary energization, thereby suppressing abnormal heat generation at the contact portion between the plate body 6 and the lower electrode 12 and eliminating the burnt color. Thus, an unexpected effect was obtained that the product quality of the joined product was improved, the wear of the lower electrode 12 was prevented, and the life was prolonged.
Further, by adopting the collar member 16, the plate member 6 is pressed by the collar member 16 on a wide surface, so that the plate member 6 is not warped, and the contact portion between the plate member 6 and the lower electrode 12 is not affected. Abnormal heat generation such as electric discharge was suppressed, and the product quality of the joined product was improved.

From this, the applied pressure at the time of secondary energization may be the same as at the time of primary energization, and the applied pressure at the time of secondary energization is a pressure at which the back surface of the plate body 6 is not eroded between the plate body 6 and the lower electrode. It is thought that it should be added. In addition, it is considered that the applied pressure at the time of secondary energization should be a pressure proportional to the magnitude of the energization current. Furthermore, the pressurizing force at the time of the secondary energization is related to the strength of the joined product, particularly the plate body itself, and thus an appropriate pressurizing force is desired.
Based on the above (including the test results), the applied pressure during secondary energization should be 1/2 or more, preferably 2/3 or more of the applied pressure during primary energization, and less than or equal to the applied pressure during primary energization. Is preferred.

Carbon steel (low carbon steel and high carbon steel), carbon alloy steel, carbon steel for machine structure, alloy steel for machine structure, steel for general processing, as materials of members (metals) related to press-fitting according to the above-described embodiment SUS (stainless steel), a combination of SUS and carbon steel, heat-resistant steel, tool steel, spring steel, cast iron, free-cutting steel, bearing steel, steel for pressure vessels, other metal materials, etc. Is possible. Moreover, in this press-fit joining, any combination of the above materials such as low carbon steels, low carbon steels and high carbon steels, high carbon steels, the same material steel, different material steels, and the like can be used.
In addition, similar effects can be expected for alloys of steel and other metals, light metals such as aluminum, and metal materials such as magnesium, nickel, and copper. For example, aluminum is expected to prevent bulging and the like and to promote solid phase diffusion by secondary energization.

  The manufacturing method and manufacturing apparatus according to the above-described embodiment can be used for manufacturing element parts such as automobiles, motorcycles, and industrial machines. For example, transmission control lever components, shift lever components, sprockets, gears, etc. It is suitable for the manufacture of products such as parts in the form of joining the second member (shaft body) to the first member (plate body) or engine parts.

  Therefore, according to the manufacturing method and the manufacturing apparatus of the product by press-fitting according to this embodiment, the shaft body can be prevented from being crushed (expanded), and the control of the press-fitting depth of the shaft body can be accurately performed. As a result, the accuracy of the joined product is improved, and the abnormal heat generation at the contact part such as the plate body is suppressed to prevent the occurrence of burnt color, so the product quality is improved, and the manufacturing method is simple and economical. There is an effect that it is excellent. In addition, press-fit welding with primary energization and secondary energization with applied pressure contribute to improving the quality and uniformity of the quality of the product as a bonded product, and toughness, strength, etc. are effectively secured and excellent products are obtained. can get.

4 hole 6 first member (plate body)
8 Second member (shaft)
9 Insertion part 10 Upper electrode 12 Lower electrode 14 Electrode piece 16 Color member 20 Pressing part 36 Covering part

Claims (7)

A method of manufacturing a joined product obtained by press-fitting a first member in which a hole is formed and a second member having an insertion portion,
The first member and the second member are both made of metal,
A press-fitting allowance is provided in the insertion portion of the second member with respect to the hole of the first member,
While the first member is disposed on the upper surface of the lower electrode, the second member is held by the upper electrode, and the lower portion of the second member is protruded downward from the lower pressing portion of the upper electrode,
Between the pressing portion of the upper electrode and the upper portion of the first member, a ring shape having an insertion hole portion in the center or a shape in which a plurality of divided pieces are combined in a ring shape, and an insulating or base material A collar member with insulating coating is provided on the
The insertion part of the second member inserted into the insertion hole is aligned with the hole of the first member, and the primary electrode is energized between the two members together with the pressure applied by the upper electrode to join the two members. The part is heated and softened, and the insertion part is press-fitted into the hole of the first member,
As the upper electrode is lowered, the pressing force applied by the pressing portion of the upper electrode is applied to the lower electrode through the collar member and the first member until the second member is pressed. Press-insert the insertion part into the hole and perform press-fit joining by solid phase diffusion,
After the temporary energization is stopped, secondary energization is performed between the two members in a state accompanied by the pressure applied by the upper electrode, and the secondary energization is stopped after heating the joint portion and the vicinity thereof. A method for manufacturing a joined product, characterized by performing heat treatment by subsequent energization.   Instead of the collar member, a covering portion provided with an insulating coating is provided below the pressing portion of the upper electrode, and the pressure applied by the pressing portion of the upper electrode is passed through the covering portion and the first member. 2. The method for manufacturing a joined product according to claim 1, wherein the state is applied to the lower electrode.   3. The method for manufacturing a joined product according to claim 1, wherein both the first member and the second member are members made of steel.   The method for manufacturing a joined product according to any one of claims 1 to 3, wherein the side surface portion of the second member is mechanically sandwiched by an upper electrode having a plurality of electrode pieces.   The collar member is formed in a ring shape, and when the collar member is attached to the pressing portion of each electrode piece of the upper electrode, screw holes are provided at a plurality of positions of the collar member, and screws having a diameter smaller than the screw holes are provided. 5. The method for manufacturing a joined product according to claim 4, wherein a play is provided between the two and screwed.   The pressurizing force at the time of secondary energization is set to 1/2 or more, preferably 2/3 or more of the pressurizing force at the time of primary energization, and below the pressurizing force at the time of primary energization. Item 6. A method for producing a bonded article according to any one of Items 5 to 9.   A bonded article manufactured by the method for manufacturing a bonded article according to any one of claims 1 to 6.

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