JP2000135569A - Manufacture of press molding roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a press molding roller which is effective to restrain excess upsizing of the roller by forming a hub of a roller core mainly with a costly effective press molding, and adopting a projection welding for the joint style of the hub. SOLUTION: A metallic hub 21 of a roller core comprises hub members 22 and 23 which are divided into two by press molding. A jointing convex part 22d protruded at the overlap portion of one hub member 22 abuts on an overlap portion (concave groove part) 23c of the other hub member, and both hub members 22 and 23 are sandwiched between cathode and anode 30 and 31 from the outside. Both electrodes 30 and 31 are relatively moved, and the current is conducted under the condition that the hub members 22 and 23 are pressure welded condition, so as to weld the overlap portions while the welding convex part 22d is melted. The electrodes 30 and 31 have the dimension approximately similar to the hub members 22 and 23, and the entire hub members are pressurized from the outside, whereby a special welding allowance for electrodes does not require to be provided to one part of the hub member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a press forming roller of a wheel member used for power transmission or running of general industrial equipment or apparatus by a projection welding method.

[0002]

2. Description of the Related Art Generally, most of various rollers for power transmission, traveling wheels, traveling guides and the like have a basic structure in which a buffer tire is provided as an outer peripheral wheel on the outer periphery of a hub of a roller cored bar. If you classify the hub by material and processing form,
In addition to cast products, press-formed products of metals and resins, there are also products made of cans made of metal, and products machined by cutting metal.

FIG. 5 is a sectional view showing a roller formed by a machined metal hub. In the case of this roller 1, the hub 2 is cut out from a round bar steel material as a processing material into a ring shape having a sectional shape as shown in the figure. The outer periphery of the hub 2 is an annular concave groove 3, and a buffer tire 4 of an outer peripheral wheel made of a rubber-like elastic material or an elastic plastic material is attached to the groove surface by appropriate means such as baking. Also,
A bearing 6 such as a ball bearing is mounted on the inner periphery 5 of the ring-shaped hub 2, and is rotatable on a roller shaft (not shown) via the bearing 6. Further, in order to prevent the bearing 6 from dropping in the direction of the rotation axis CC, a flange 7 and a locking claw 8 are provided on both sides of the inner periphery 4 of the hub 2 so as to rise.

In the case of the roller 1 shown in FIG. 5, the cost is considerably high because the hub 2 is mainly made of machining. In terms of suppressing the cost, the roller 10 having the hub 11 formed by the die press molding shown in FIG. 6 is more advantageous.

The roller 10 shown in FIG. 6 includes a pair of symmetric hub members 11A and 11A in which a hub 11 is formed in a ring shape.
B, which are joined back to back. The hub members 11A, 11B are provided with annular concave grooves 11a, 11
In a state where the groove bottoms 11c provided with b are overlapped with each other back to back, the groove bottoms 11c are spot welded (shown by a symbol w in the drawing) at equal intervals over an annular groove circumference to be integrated. I have. Thereby, one hub member 1
An annular groove 12 is formed by 1A and the other hub member 11B, and a buffer tire 13 of an outer peripheral wheel is mounted in this annular groove 12 in a concave shape in cross section by appropriate means such as baking or welding. A bearing 15 such as a ball bearing is mounted on the inner periphery 14 of such a combined hub 11 as in the case of the roller 1 in FIG. 5 to enable free rotation on the roller shaft.

However, the roller 10 shown in FIG. 6 also has the following problems to be solved.
To perform spot welding, electrodes 16 and 17 of the Yin and Yang counter electrodes are prepared. In order to obtain the required electrode pressing force for welding the groove bottoms 11c of the hub members 11A and 11B, the diameter of the negative and positive electrodes 16 and 17 needs to be at least about 3 mm. In order to prevent the electrodes 16 and 17 having the same diameter from coming into contact with both wall surfaces of the annular groove 11a in the hub members 11A and 11B, the groove width dimension b must be at least about 3 mm of the electrode diameter and about 7 mm. Therefore, the annular grooves 11a and 11b must be large.

[0007] In this type of roller, the bearing 15 is shared and the hub member 11 is adapted to the outer diameter d.
There are many cases where the dimensional specifications of A and 11B are determined. At this time, the hub member 11 is connected to the negative and positive electrodes 16 and 17.
When the groove width dimension b of the annular concave grooves 11a and 11b in A and 11B is increased, there is a disadvantage that the roller outer diameter D is unnecessarily increased.

As one type of resistance welding that replaces such disadvantageous spot welding, projection welding is known in which a projection, an intersection, or an overlap is provided in a weld portion and the weld is locally welded. For example, there is a method in which a projection is provided in a welded portion, a current is applied by applying pressure, and the current and pressure are concentrated to join the portion. In this case, as shown in the spot welding in FIG.
6 and 17, the groove bottom 11 of the hub member 11 which is a welded portion.
There is no need to directly pressurize c with each other. That is, since the diameters of the negative and positive electrodes 16 and 17 are not restricted, it is not necessary to unnecessarily increase the groove width dimension b of the annular concave grooves 11a and 11b.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hub made of a roller core mainly by press forming, which is advantageous in terms of cost, and by employing projection welding as a joining form of the hub, An object of the present invention is to provide a method for manufacturing a press-formed roller which is effective for suppressing unnecessary enlargement of the roller.

[0010]

According to the present invention, there is provided a press-forming roller according to the present invention, which comprises a pair of circular press-formed rollers each having a metal hub serving as a roller core divided into two in a thickness direction. When the overlapped portions of the two hub members are joined and integrated by projection welding, a joining projection formed by projecting from the overlapped portion of one hub member is overlapped with the other hub member. The two hub members are sandwiched and set between the cathode and anode electrodes from the outside in this state, and the two hub members are moved relative to each other to apply pressure to both hub members. It is carried out by applying a current after bringing the parts into pressure contact with each other, and melting and welding the joint projections.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a press forming roller according to the present invention will be described in detail with reference to the drawings. 1 and 2 are a partial perspective view and a side sectional view of a press forming roller 20 obtained by the present manufacturing method.

The press forming roller 20 has a metal hub 21 serving as a roller core, and the hub 21 includes a pair of symmetrical hub members 22 and 23 joined back to back. For example, if one hub member 22 is represented as a representative, the hub member 22 has an outer peripheral flange 22a and an inner peripheral flange 22b which are raised in an annular shape along the side surface, and an annular concave groove portion 22c is provided between the two flanges. . As the material of the hub member 22, for example, SPCC having a plate thickness of 0.6 to 3.2 mm is used.

As is clear from FIGS. 3 (a) and 3 (b), one of the hub members 22 has a
A joining projection 22d is formed by extruding a convex shape on the back surface by depressing the groove bottom of c. This joining projection 22d is
A plurality of places at appropriate intervals in the annular circle of the concave groove portion 22c,
For example, about 4 to 8 places are provided, and they face the back surface of the concave groove portion 23c of the other hub member 23. Groove 2
The dimension ratio h / w of the groove height h and the groove width w of 2c is 0.5 to
It is set to about 10.0. The hub members 22 and 23 formed by press molding in such a shape are shown in FIGS.
In the step shown in FIG.

As shown in FIG. 4A, the hub member 22,
23 is set up and down in the vertical direction. That is,
The hub 22 is positioned so that the joint projection 22d of the hub member 22 faces downward and abuts against the back surface of the groove 23c of the hub member 23.

Next, as shown in FIG. 4B, a pair of anodes 30 and cathodes 31 are set so as to sandwich the upper and lower hub members 22 and 23 and abut against them from outside.
These poles 30 and 31 are donut disk shapes having substantially the same outer diameter as the hub members 22 and 23, and are capable of moving up and down relatively in the vertical direction. For example, the upper anode 30
Is a vertical movement mechanism that approaches and separates from the lower cathode 31, the power supply 32 is turned on and electricity is supplied between the two electrodes 30, 31 to lower the upper anode 30. Then, the hub members 22 and 23 are pressed from above and below by the pressing force with the lower cathode 31. By this operation, the current and the pressure are concentrated on the joint protrusion 22d of the upper hub member 22.

As a result, as shown in FIG. 4 (c), the joining projection 22d is melted and the recessed groove 23 of the lower hub member 23 is melted.
Weld to the position substantially flush with the back surface of the groove bottom of c. This welded portion is indicated by reference numeral 22e in the figure. As a result, an integrated hub 21 is obtained by joining the upper and lower hub members 22 and 23 at the back surface. On the outer periphery of the hub 21 after the joining, outer peripheral flanges 22a and 23a stand up on both sides to form an annular concave groove, and a buffer tire 24 made of a rubbery elastic material or an elastic plastic material is burned on the surface of the concave groove by appropriate means such as baking. Mounted on. A bearing 25 of a ball bearing is mounted on the inner periphery of the hub 21 after the joining, and the raised inner peripheral flanges 22b and 23b prevent the bearing 25 from dropping in the direction of the rotation axis CC.

[0017]

The present invention relates to a method for manufacturing a press-formed roller which can reduce the cost considerably as compared with a roller formed by machining. In addition, adoption of projection welding, which allows simultaneous welding of many points at one time, eliminates the need for an extra welding margin (shiro) as in the case of conventional spot welding when setting the hub dimensions. It is effective for conversion.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view showing a part of a press forming roller obtained by a method of the present invention.

FIG. 2 is an assembled side sectional view of a press forming roller.

FIGS. 3A and 3B are a plan view and a side sectional view, respectively, showing a part of a hub which is a main member of the press-forming roller.

FIGS. 4A to 4C are side cross-sectional views sequentially showing steps (a) to (c) of joining and integrating the hub of the press-forming roller by projection welding.

FIG. 5 is an assembled side sectional view of a roller mainly formed by machining shown as a conventional example.

FIG. 6 is an assembled side sectional view of a press-formed roller formed by spot welding shown as a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 press forming roller 21 hub 22, 23 member constituting hub 22 c, 23 c hub member concave groove portion 22 d joining convex portion 22 e projection welding welded portion 24 buffer tire 25 bearing 30 anode 31 cathode 31

Claims (3)

[Claims] 1. A metal hub serving as a roller core comprises a pair of circularly press-formed hub members which are divided into two in a thickness direction. When joining and integrating by welding, the joining protrusion formed by projecting from the overlapping portion of one hub member is brought into contact with the overlapping portion of the other hub member and positioned, and both hubs are positioned in that state. Set the member by sandwiching it between the electrodes consisting of the cathode and the anode from the outside,
A method of manufacturing a press-forming roller, characterized in that the two electrodes are moved relative to each other to apply pressure to the two hub members so that they are brought into pressure contact with each other, and then energized to melt and weld the joint projections. 2. A joining projection is formed at a plurality of locations at intervals around the circumference of the overlapped portion of one hub member, and pressure and electric power are concentrated on the joining projection by both electrodes to simultaneously weld. The method for manufacturing a press forming roller according to claim 1. 3. A press-formed roller manufactured by the method according to claim 1.