JPH08257653A - Method for joining metallic parts - Google Patents

Abstract

PURPOSE: To eliminate the initial deviation of a joined parts, and to improve the fracture strength by forming a surface groove of approximately V-shaped section in a joining method of a metallic parts where the surface groove is formed in a shaft-shaped member, the shall-shaped member is inserted in a tubular member, and a recessed groove is formed in the end face of the tubular member by a press to achieve the joining. CONSTITUTION: Surface grooves 11, 12 are formed circumferentially in a shaft- shaped member 1, and annular recessed parts 22, 23 are formed by a press with a tubular member 2 inserted thereto. The wall of the tubular member 2 is filled the surface grooves 11, 12 by forming the annular recessed parts 22,23, and the shaft-shaped member is firmly joined with the tubular member 2. Because the section of the surface grooves 11, 12 is of V-shape having the opening angle of 90-100 deg., the stock of the tubular member 2 is easily pushed out into the surface groove to fill the space in an approximately complete manner, and the contact area in the surface grooves 11, 12 is greatly improved compared with the conventional one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining method for metal parts, and more particularly to a joining method suitable for joining one part to another metal part so that both parts can be joined together.

[0002]

2. Description of the Related Art Conventionally, when joining two parts, at least one of which is made of metal, there are a method of bonding with an adhesive and a method of welding such as spot welding. Is preferable in that it can be fixed as it is, but the bonding strength may change significantly depending on the filling state of the adhesive and the welding state, and it is difficult to obtain the reliability of the bonding. is there.

On the other hand, in the method of plastically deforming a metal part to fix it by caulking, the caulking part is formed in a specific shape in advance, and the part is deformed by a press or the like to be engaged with another part. It is a thing. Therefore, it is possible to obtain a highly reliable joined state while requiring a prior processing.

As one of the methods for fixing by caulking,
When joining a shaft-shaped member and a metal tubular member having a through hole through which the shaft-shaped member is inserted, first, as shown in FIG. 7, an annular surface groove is formed on the peripheral surface of the shaft-shaped member 3. 31, 32
Is formed into a rectangular cross section, and then the shaft-shaped member 3 is attached to the tubular member 4
The end surface 4 of the tubular member 4 while being inserted into the through hole 41 of
There is a method in which the tubular members 4 are plastically deformed by forming annular recesses 42 and 43 in a and 4b by press working, and the meat is moved into the surface grooves 31 and 32 of the shaft-shaped member 3. In this way, the meat of the tubular member 4 engages with the surface grooves 31, 32 of the shaft-shaped member 3, so that the shaft-shaped member 3 and the tubular member 4 can be relatively firmly joined.

[0005]

In the above-described conventional joining method by plastic deformation, a relatively large joining force can be obtained, and a trace due to the joining is not relatively left outside (end surfaces 4a and 4b of the tubular member 4). A recess 41 formed in
Except for 42, it does not appear on the appearance. Therefore, it is suitable when the shape of the joined component is restricted. However, in this joining method, since the meat of the tubular member 4 fits inside the surface grooves 31 and 32 having a rectangular cross section, the joining strength seems to be high. It is not sufficient, and when a relatively small stress is applied, an initial displacement occurs, and it is possible to withstand a certain amount of stress thereafter, but there is a problem that the fitting portion is eventually broken and damaged.

Therefore, the present invention solves the above-mentioned problems, and an object thereof is to prevent the initial displacement and improve the breaking limit strength as compared with the conventional case when joining the shaft-shaped member and the tubular member as described above. Is to let.

[0007]

Means for Solving the Problems The means taken by the present invention to solve the above-mentioned problems is a method for joining metal parts in which an insertion part and a metal part to be inserted which is inserted into the insertion part are joined together. A surface groove having a substantially V-shaped cross section is formed on an outer surface of the insertion component facing the insertion metal component, and in the vicinity of an edge portion of the insertion metal component, It is characterized in that stress is applied to the edge portion to cause plastic deformation, and the deformed portion of the inserted metal component is engaged with the surface groove to be joined.

Here, it is preferable that the bottom end of the substantially V-shaped cross section of the surface groove is formed into a curved or flat shape.

Further, it is preferable that a concave groove is provided at the end edge portion by applying the stress, and a side surface of the concave groove on the side of the inserting component is inclined with respect to the inserting direction.

In this case, it is desirable that the inclination angle of the side surface of the groove on the side of the insertion part with respect to the insertion direction of the insertion part is set large, and the inclination angle of the side surface on the opposite side is formed small.

[0011]

According to the present invention, since the surface groove has a substantially V-shaped cross section, the surface groove can be easily filled by the plastic deformation of the inserted metal component, so that the inserted component and the inserted metal component are separated from each other. Since the contact area on the inner surface of the surface groove increases, the initial displacement under low stress does not occur and the fracture strength can be greatly improved.

According to the second aspect, the bottom end of the surface groove is cut into a curved surface or a flat surface,
Since the contact area of the material of the inserted metal component to be filled is further increased and the non-contact portion can be almost eliminated, the breaking strength can be further improved.

According to the third aspect, when the concave groove is formed on the inserted metal component, the side surface of the concave groove on the insertion component side is formed so as to be inclined with respect to the insertion direction. Since the material of (3) can be directly pushed into the surface groove side, an engaged state with good adhesion with the surface groove can be realized reliably and with good reproducibility.

According to the fourth aspect of the present invention, by increasing the inclination angle of the side surface of the concave groove on the side of the insertion component and decreasing the inclination angle of the side surface on the opposite side, the portion of the inserted metal component facing the surface groove is made plastic. While being able to be reliably engaged with the surface groove by the deformation, it is possible to minimize the deformation of other inserted metal parts such as the outer diameter thereof.

[0015]

Embodiments of the method for joining metal parts according to the present invention will now be described with reference to the drawings. In this joining method, as shown in FIG. 1, surface grooves 11 and 12 are formed in advance on the peripheral surface of the shaft-shaped member 1. The surface grooves 11 and 12 have a substantially V-shaped cross section and have an opening angle of about 90 to 100 degrees. The surface grooves 11 and 12 respectively include two inclined side surface portions 11a and 11b and these side surface portions 11a and 11b.
A bottom portion 11c formed with a small width is provided between b.

On the other hand, the tubular member 2 is provided at its center with a through hole 21 through which the shaft-shaped member 1 is inserted almost exactly, and the initial inner surface of this through hole 21 is a cylindrical surface. When the shaft-shaped member 1 is inserted into the through hole 21, as shown in FIG.
The surface groove 1 is formed in the state as shown in (a).
The pipes 1 and 12 are attached to the die 5 of the press shown in FIG. 2B so that the pipes 1 and 12 come near the end faces 2a and 2b of the tubular member 2. Here, the formation positions of the surface grooves 11 and 12 are set in advance so as to be hidden inside the tubular member 2 near the end surfaces 2a and 2b of the tubular member 2.

Further, as shown in FIG. 2B, the die 5
The punch 6 of the press applies pressure to the two parts attached to the. An annular rib 6a is formed on the punch 6, and the rib 6a pressurizes the end surface 2a of the tubular member 2 to form an annular recess 22 shown in FIGS. 1 and 2A. Due to the formation of the annular recess 22, the tubular member 2
Is plastically deformed, and the meat of the tubular member 2 is extruded into the surface groove 11.

By the same process, a similar annular recess 23 is formed in the end surface 2b on the opposite side of the tubular member 2, and the meat of the annular member 2 is also pushed into the surface groove 12. Thus, in this embodiment, the shaft-shaped member 1
And the tubular member 2 are the surface grooves 11 and 12 of the shaft-shaped member 1,
It is firmly fixed by the engagement with the protruding portion of the tubular member 2 extruded into the surface grooves 11, 12. It is also possible to form the annular recesses 22 and 23 at the same time in one pressing process or forging process by providing the die 5 with ribs similar to the ribs 6a.

The difference between the engaging portion in this embodiment and the conventional engaging portion having a rectangular cross section will be described below with reference to FIGS. 1 and 7. In the conventional surface grooves 31 and 32 having a rectangular cross section, since the side surface portions thereof are formed substantially perpendicular to the axis of the shaft-shaped member 3, the joint strength of the shaft-shaped member 3 and the tubular member 4 in the axial direction is formed. Tends to be high, but
Actually, it is difficult to completely fill the surface grooves 31, 32 with the meat of the tubular member 2. As shown in FIG. 7, the meat of the tubular member 4 is extruded in a chevron shape with respect to the rectangular cross section of the surface grooves 31, 32. Be done. Therefore, the opening edge portions of the surface grooves 31 and 32 and the chevron-shaped meat of the tubular member 4 are in point contact (actually line contact) as a sectional shape in an extreme case.

As a result, the shaft-shaped member 3 and the tubular member 4
If a stress is applied in the axial direction of the shaft-shaped member 3 between the shaft-shaped member 3 and the tubular member 4, the contact portions between the opening edge portions of the surface grooves 31 and 32 and the chevron portion of the tubular member 4 are broken. A phenomenon (initial deviation) occurs in which and move relatively slightly. Although this initial deviation is slight, it causes the dimensions of the joint parts to be distorted and causes a fatal defect in the construction mechanism.

On the other hand, in the case of the present embodiment, as shown in FIG. 1, since the substantially V-shaped surface grooves 11 and 12 are formed in the shaft-shaped member 1, the surface grooves 11 and 12 are formed inside. Tubular member 2
The material is easy to enter. It is preferable that the tubular member 2 is made of a forging metal material, but if the forging material is not a forging material, the tubular member 2 is almost completely inside the surface grooves 11 and 12 due to a predetermined ductility as long as it is a metal material. It is possible to fill two materials. In this way, in this embodiment, the contact area with the tubular member 2 in the surface grooves 11 and 12 is larger than that in the conventional case, so that the initial displacement does not occur and the final breaking strength is significantly increased.

In this case, the bottom surface portion 11 is formed in the surface grooves 11 and 12.
By providing c and 12c, the filling property of the material of the tubular member 2 can be further improved, and the bonding strength can be further improved. The width of the bottom surface portion of each of the bottom surface portions 11c and 12c may be considerably smaller than the opening width of the surface groove, and may not be flat but may be curved. In this embodiment, the bottom surface portions 11c and 12c are formed so that the surface groove 11
The mutual angles of the side surface and the bottom surface of 12 are all obtuse angles, and the filling property by the plastic deformation of the metal is improved.

The V-shapes of the surface grooves 11 and 12 need to be appropriately set depending on the material of the tubular member 2 and the position where the surface grooves are formed. Generally, the side surfaces of the surface grooves 11 and 12 are inclined. The angle is preferably 45 degrees or slightly larger, and the opening angle of the V-shape is preferably in the range of 90 to 100 degrees.

In the above-described embodiment, the annular recesses 22 and 23 formed by pressing or the like have a tubular member 2 shape.
Since it suffices to plastically deform and engage the inside of the surface grooves 11 and 12, any shape may be originally used. However, the deformation amount of the tubular member 2 with respect to the entire shape is reduced as much as possible,
Moreover, when it is attempted to secure a portion that moves inside the surface grooves 11 and 12, as shown in FIG. 1, a direction orthogonal to the axial direction of the shaft-shaped member 1, that is, in the case of the present embodiment, the tubular member 2 The outer side surface 22a has a steep angle with respect to the end surfaces 2a and 2b (the inclination angle with respect to the insertion direction or the axial direction is made small), and the inner side surface 22b has a gentle angle (the insertion direction or the axial direction). Increase the tilt angle with respect to
Thereby, the material of the tubular member 2 is pushed and deformed toward the surface grooves so as to be sufficiently engaged with the surface grooves 11 and 12, while being deformed in other directions of the tubular member 2, for example, the outer peripheral direction of the tubular member 2. However, the deformation amount is reduced as much as possible.

When actually forming the annular recesses 22 and 23, since the joined parts are housed and processed in the die of the press,
For example, by performing press working using a die that matches the outer circumference of the tubular member 2, the working can be performed without changing the outer diameter of the tubular member 2. Similarly, the tubular member 2
With respect to the length in the axial direction of the, if the die is configured so as to be flat-pressed to a predetermined dimension during the press working, the deformation can be prevented and the working can be performed accurately.

FIG. 3 shows another embodiment having a shape different from that of the above embodiment. This embodiment shows a case where the tubular member 7 is joined while being inserted into the ring-shaped member 8. An annular surface groove 71 having a substantially V-shaped cross section is formed on the outer peripheral surface of the tubular member 7. The ring-shaped member 8 is formed with a through hole 81 through which the tubular member 7 is inserted, and the inner surface of the through hole 81 is a cylindrical surface.

When the annular recess 82 is formed on the end face 8a of the ring-shaped member 8 by pressing with the tubular member 7 inserted through the ring-shaped member 8, the ring-shaped member 8 is deformed and the surface thereof is changed as in the above-described embodiment. It engages in the groove 71. Here, since the ring-shaped member 8 is thin, unlike the embodiment shown in FIG. 1, one set of surface grooves and one annular recess are formed. Even with such a structure, sufficient bonding strength can be obtained.

In this embodiment, when the ring-shaped member 8 is formed by press working, the ring-shaped member 8 has a curved shape in the drilling direction of the through-hole 81 (that is, the axial direction of the member). In the step of joining with the member 7, when the ring-shaped member 8 is deformed by a press, the annular recess 82
The flatness of the ring-shaped member 8 can be obtained by simultaneously punching the end surface 8a other than the portion where the ring-shaped member 8 is formed. As a result, since it is possible to perform the joining process at the same time in the conventional flat stamping process, there is an advantage that the joining can be performed without increasing the manufacturing process.

In the above-mentioned two embodiments, the surface groove that circulates around the outer peripheral surface of the shaft-shaped member 1 or the tubular member 7 that is the insertion member is formed. It may be formed so as to extend in an arbitrary direction only in a part thereof. In addition, the shape of the insertion member is not particularly limited, and may have any shape such as a square shape and a plate shape in addition to the circular cross section as in the above embodiment. further,
Although the annular recess is formed in the tubular member 2 or the ring-shaped member 8 which is the inserted metal member, it is not formed in an annular shape but may be formed in any shape as long as it is formed in the vicinity of the surface groove. be able to. This shape may be formed in advance on the end surface of the inserted metal member instead of the concave portion and pressed by a press to flatten it.

FIG. 4 is a perspective view showing a joint member joined according to the above embodiment, in which a tubular member 2 or a ring-shaped member 8 which is a metal member to be inserted is fixed, and the axial member 1 or the tubular member 7 which is an insertion member is axially moved. It shows the relationship between the pressing force when a stress is applied and the amount of deformation in the axial direction. FIG. 4 (a) is measured with respect to a joint component engaged with a conventional surface groove having a rectangular cross section, and FIG. 4 (b) is engaged with a surface groove having a substantially V-shaped cross section in the embodiment. It is measured for the joined parts.

As shown in FIG. 4, in the case of the joined parts produced by the conventional joining method, the initial deviation A is generated at a relatively low pressure and the breaking strength B is also low, whereas the joining method of this embodiment is used. In the joined parts thus made, no initial deviation occurs, and the fracture strength C is considerably improved.

FIG. 5 shows the test apparatus used for the above test. This device is for measuring a pressing force of the pressing rod 92 and a jig 91 for supporting the inserted metal member E joined to the insertion member D, a pressure rod 92 for applying a stress to the insertion member D from above. The load cell 93 and a measuring device 94 that receives a detection signal from the load cell 93 and measures the applied pressure. Here, the pressure rod 92 is adapted to apply pressure downward by a pressure device (not shown) and slowly increase this pressure at a predetermined rate of change.

The measuring device 94 is configured to display the pressure applied to the insertion member D by the load cell 93 and finally obtain the maximum value of the pressure gradually increased by the pressurizing device. When the pressure of the pressurizing rod 92 increases and the joint portion of the joint component is destroyed in due time, the display of the maximum pressing force at the time of destruction can be held,
It is possible to obtain the breaking strength of the joint portion of the joint component.

Table 1 shows the results of the ten breaking test pieces shown in FIG. 6 (a) being made on a trial basis using the above test equipment, and the breaking strengths of these pieces being obtained. In this joint component, the insertion member D is a shaft-shaped member made of a sulfur composite free-cutting steel having a diameter of 12 mm, and the inserted metal member E is a ring-shaped member made of a rolled steel plate having a thickness of 2.0 mm. The position of the surface groove is determined so that the end of the opening of the groove comes to a position of 0.15 mm from the end surface of the inserted metal member, and the depth of the surface groove is 0.3 m.
m, the width of the bottom portion is 0.1 mm, and the opening angle of the V-shape is 95 degrees. In addition, the depth of the annular recess is 0.35
The inclination angle of the outer side surface is 0.45 mm, the inclination angle of the inner side surface is 40 to 55 degrees, and the width of the bottom surface portion sandwiched by both side surface portions is 0.3 mm. Meanwhile,
As a comparative example showing a conventional joining method, measurement was performed also in the case where the surface groove had a rectangular cross section and other conditions were the same as above.

[0035]

[Table 1] Fracture strength (kg) Part number [Example] [Comparative example] 1 1257 851 2 1251 839 3 1260 844 4 1255 852 5 1235 848 6 1280 846 7 1278 847 8 1280 844 9 1276 847 8 12 10

As can be seen from this data, the fracture strength is improved by about 50% in all the joined parts. Further, the initial deviation was observed in the joint parts using the comparative example, whereas no initial deviation was observed in all the joint parts using the examples. The volume ratio of the surface groove to the annular recess is preferably about 100% or slightly larger in the annular recess. If the volume of the surface groove is larger, the joint strength is reduced due to insufficient filling, and if the volume of the annular recess is larger, the inserted metal member is more deformed.

In the same manner as described above, a shaft member D made of sulfur composite free-cutting steel having a diameter of 6 mm shown in FIG.
m, a joint part with a ring-shaped member E made of a cold-rolled steel plate, a shaft-shaped member D made of stainless steel having a diameter of 3 mm and a hardness Hv = 1100 shown in FIG. 6C, and a sulfur composite free-cutting steel having a thickness of 20 mm. 6D, a shaft-shaped member D made of a sulfur composite free-cutting steel having a diameter of 25 mm and a thickness of 2.9.
mm, a joint part with a ring-shaped member E made of a cold rolled steel plate,
6 (e) shows a joint part of a shaft member D made of stainless steel having a diameter of 4 mm and a hardness Hv = 1100 and a cylindrical member E made of sulfur composite free-cutting steel having a thickness of 25 mm, and FIG. 6 (f). A test was performed on each of the joined parts of the shaft-shaped member D made of a sulfur composite free-cutting steel having a diameter of 8 mm and the ring-shaped member E made of a cold-rolled steel plate having a thickness of 3.2 mm. Here, these joined parts are joined by providing surface grooves and annular recesses that are substantially the same as those shown in FIG. 6 (a). The breaking strength of these joined parts is shown in Table 2 below.

Breaking strength (kg) Part number FIG. 6 (b) FIG. 6 (c) FIG. 6 (d) FIG. 6 (e) FIG. 6 (f) 1 311 618 1870 810 510 510 2 307 617 1802 810 521 3 318 613 1886 815 520 4 312 512 616 1854 818 521

With regard to the joint parts shown in the above data, the joint strength between the inserted part and the inserted part is significantly improved as compared with the conventional joint part, regardless of the structure of the joint part. ing. In addition, no initial deviation was observed in any of the joined parts. As described above, according to each of the above-described embodiments, by forming the cross-sectional shape of the surface groove into a substantially V shape, the breaking strength can be remarkably improved as compared with the conventional joining method, and it is a drawback of the conventional method. Also, there is an extremely remarkable effect that the initial deviation does not occur and the dimensional accuracy does not fluctuate when the stress is reduced.

[0040]

As described above, the present invention has the following effects.

According to the first aspect, since the surface groove has a substantially V-shaped cross-section, the surface groove can be easily filled by the plastic deformation of the inserted metal component, and the inserted component and the inserted metal component are separated from each other. Since the contact area on the inner surface of the surface groove increases, the initial displacement under low stress does not occur and the fracture strength can be greatly improved.

According to the second aspect, the bottom end of the surface groove is cut into a curved surface or a flat surface,
Since the contact area of the material of the inserted metal component to be filled is further increased and the non-contact portion can be almost eliminated, the breaking strength can be further improved.

According to the third aspect, when the concave groove is formed in the inserted metal component, the side surface of the concave groove on the insertion component side is formed so as to be inclined with respect to the insertion direction. Since the material of (3) can be directly pushed into the surface groove side, an engaged state with good adhesion with the surface groove can be realized reliably and with good reproducibility.

According to the fourth aspect of the present invention, by increasing the inclination angle of the side surface of the concave groove on the side of the insertion component and decreasing the inclination angle of the side surface on the opposite side, the portion of the inserted metal component facing the surface groove can be made plastic. While being able to be reliably engaged with the surface groove by the deformation, it is possible to minimize the deformation of other inserted metal parts such as the outer diameter thereof.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing a structure of a joint part to which an embodiment of a method for joining metal parts according to the present invention is applied.

FIG. 2 is a perspective view (a) showing an external shape of a joined component joined by the embodiment and a schematic sectional view (b) showing a state at the time of joining.

FIG. 3 is a perspective view (a) and a cross-sectional view (b) of a joining component showing a case where the embodiment is applied to components having different shapes.

FIG. 4 is a graph showing a relationship between a pressing force and a deformation amount (positional deviation between joined parts) when a pressure is applied to the joined parts, which is for a joined part joined using a conventional joining method ( (a) and (b) for the joined parts joined according to the examples.

FIG. 5 is an explanatory view showing a test device for measuring the breaking strength of a bonded component.

6A to 6F are cross-sectional views (a) to (f) showing the shapes of the joined parts tested.

FIG. 7 is an enlarged cross-sectional view showing a joint portion using a conventional joining method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft-shaped member 2 Tubular member 5 Die 6 Punch 7 Tubular member 8 Ring-shaped member 11, 12, 71 Surface groove 22, 23, 82 Annular recess

Claims (4)

[Claims] 1. A method of joining a metal component for joining an insertion component and an insertion metal component that is inserted into the insertion component, the method comprising: an outer surface of the insertion component that faces the insertion metal component; A surface groove having a substantially V-shaped cross section is formed in the vicinity of the end edge portion of the inserted metal component, and stress is applied to the end edge portion of the inserted metal component to plastically deform the deformed portion of the inserted metal component. A method for joining metal parts, comprising: engaging with the surface groove to join. 2. The method for joining metal parts according to claim 1, wherein the bottom end portion of the substantially V-shaped cross section of the surface groove is formed into a shape cut into a curved surface or a flat surface. 3. The groove according to claim 1, wherein the end edge portion is provided with a concave groove by applying the stress, and a side surface of the concave groove on the side of the insertion component is formed to be inclined with respect to the insertion direction. A method for joining metal parts, comprising: 4. The method according to claim 3, wherein the inclination angle of the side surface of the recess on the side of the insertion part with respect to the insertion direction of the insertion part is set large, and the inclination angle of the side surface on the opposite side is formed small. And method of joining metal parts.