JP2003004061A - Outer ring member for constant velocity joint and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To manufacture an outer ring member for a constant velocity joint efficiently at low cost. SOLUTION: After a workpiece 20 having a diameter substantially equal to a diameter of a cup portion 8 of an outer ring member 1 for a tripod constant velocity joint, which is a finished product, is subjected to annealing, shot blasting, and formation of a chemical conversion coating for lubrication, Cold forging is performed using the forging die apparatus 30. At this time, the punch 66 is lowered with the distal end surface of the shaft portion 6 formed in the shaft portion forming cavity 44 abutting on the distal end surface of the knockout pin 55, thereby facing the work 20 on the punch 66 side. One end face is crushed to form the cup portion 8, and the cup portion 8 is provided with roller grooves 9a to 9c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer ring member for a constant velocity joint and a method of manufacturing the same, and more specifically, an outer ring member for a constant velocity joint which is remarkably small in the number of steps and is efficiently manufactured for this reason, and the same. It relates to a manufacturing method.

[0002]

2. Description of the Related Art FIG. 9 shows a driving force transmission mechanism for transmitting a driving force from an internal combustion engine mounted on an automobile or the like to an axle. In this drive force transmission mechanism, the triport type constant velocity joint outer ring members 1, 1 and the barfield type constant velocity joint outer ring members 2, 2 are spline shafts 3,
3 are connected to each other. The differential device 4 is provided between the outer ring members 1 and 1 for the triport type constant velocity joint.
Is installed. The triport type constant velocity joint outer ring members 1 and 1 are both disposed on the differential device 4 side, while the Burfield type constant velocity joint outer ring members 2 and 2 apply rotational driving force to a wheel (not shown). Performs the function of transmitting. In FIG. 9, reference numeral 5 indicates a half shaft that bridges the outer ring member 1 for a tripod type constant velocity joint and the differential device 4.

Here, a partially cutaway sectional view of the outer ring member 1 for a tripod type constant velocity joint is shown in FIG. 10 and a schematic front view is shown in FIG. The outer ring member 1 for a tripod type constant velocity joint is made of carbon steel, and includes a shaft portion 6 and a cup portion 8 having a boss portion 7 formed in a protruding manner.

Of these, three roller grooves 9a to 9c are formed in the cup portion 8 at equal intervals along the circumferential direction (see FIG. 11). These roller grooves 9a to 9c are for rolling the rollers of a constant velocity joint (not shown), and extend along the axial direction of the outer ring member 1 for a tripod type constant velocity joint to the vicinity of the end portion of the cup portion 8. Are provided (see FIG. 10).

The outer ring member 1 for a tripod type constant velocity joint is manufactured by cold forging as follows. First, as shown in FIG. 12A, a pretreatment is performed on the work 10 that is a cylindrical body having a diameter slightly larger than that of the shaft portion 6. That is, this work 10 made of carbon steel is subjected to spheroidizing annealing in which the cementite is spherically precipitated in the metal structure, and subsequently, a lubricating conversion coating is formed on the surface thereof. In general cold forging, a zinc phosphate coating is often used as a lubricating conversion coating.

Next, a first forging die (not shown) is used to subject the work 10 on which the lubricating chemical conversion coating has been formed to a primary forging process (forward extrusion molding). That is,
The one end surface of the work 10 is pressed toward the cavity formed in the first forging die and having a diameter smaller than that of the work 10. Along with this, the other end surface side of the work 10 is press-fitted into the cavity, and as a result, as shown in FIG. 12B,
A primary molded product 12 in which a reduced diameter portion 11 having a tapered diameter and a shaft portion 6 are formed on the other end surface side is obtained.

Next, the secondary forging process (upsetting) is performed on the primary molded product 12. Specifically, using a second forging die (not shown), as shown in FIG. 12C,
By compressing only the large-diameter portion 13 of the primary molded product 12, the large-diameter portion 13 is expanded in diameter to form a secondary molded product 14.

Then, with respect to the secondary molded product 14,
Low temperature annealing for stress relief, shot blasting treatment for removing oxide scale and the like generated during the low temperature annealing,
Then, a lubricating chemical conversion coating made of zinc phosphate or the like is formed on the outer surface of the secondary molded product 14.

Next, after the above-mentioned treatments have been carried out, the expanded large diameter portion 13 is stretched with respect to the secondary molded product 14 placed in the cavity of the third forging die (not shown). Roller grooves 9a to 9c are formed in the large diameter portion 13 and a cup portion 8 is provided (reverse extrusion molding). That is, a punch (not shown) having a protruding portion for forming the roller grooves 9a to 9c is brought into contact with the central portion of one end surface of the cup portion 8,
Subsequently, the tip end of the shaft portion 6 is pressed to displace the secondary molded product 14 toward the punch. As a result, the large diameter portion 13
The secondary molded product 14 in the state of being surrounded by the inner wall of the cavity is crushed by the punch, and eventually the large diameter portion 13 is expanded and the large diameter portion 13 corresponds to the shape of the protruding portion of the punch. Roller grooves 9a to 9c having a shape to be formed are formed. At this time, the boss portion 7 is formed by the cavity for forming the boss portion 7, and the third molded product 15 shown in FIG. 12D is obtained.

After the third molded product 15 is annealed at a low temperature to soften the third molded product 15, the shot blast treatment and the formation of the lubricating chemical conversion coating are performed again. By performing such a treatment, it is possible to suppress the occurrence of cracks on the inner surface of the cup portion 8 when performing ironing, which is the next step.

Finally, an outer ring member 1 for a tripod type constant velocity joint as a finished product is obtained by performing an ironing process (final sizing molding) for finishing a final product shape with a fourth forging die (not shown). (See FIGS. 10 and 11) are obtained.

[0012]

As can be appreciated from the above, in the manufacturing method according to the prior art, forging is performed four times from the work 10 to the manufacturing of the outer ring member 1 for a tripod type constant velocity joint. Since various processing operations are performed before the workpiece 10, the secondary molded product 14, and the tertiary molded product 15 are forged, the outer ring member 1 for a tripod type constant velocity joint is obtained. Since there are many steps, it takes a long time to complete. In other words, there is a problem that the outer ring member 1 for a tripod type constant velocity joint cannot be efficiently manufactured.

In the four times of forging, first to fourth forging dies having different structures are used. As is well known, forging dies are expensive. Therefore, in the above-described manufacturing method using four forging dies, the manufacturing cost of the outer ring member 1 for a tripod type constant velocity joint increases. After all, in the manufacturing method according to the related art, the problem that the tripod type constant velocity joint outer ring member 1 and, by extension, the vehicle on which the outer ring member 1 is mounted cannot be supplied at low cost.

The present invention has been made to solve the above-mentioned problems, and an outer ring member for a constant velocity joint can be obtained from a work by a single forging process. Therefore, a plurality of forging dies are provided. It is an object of the present invention to provide an outer ring member for a constant velocity joint and a method for manufacturing the same, which can be manufactured at low cost because it is not necessary to prepare the outer ring member.

[0015]

In order to achieve the above-mentioned object, the present invention has a diameter which is approximately equal to the external dimensions of the outer ring member for a constant velocity joint, which is a finished product having a conversion coating film for lubrication formed on its surface. A workpiece having a cylindrical portion is placed in a cavity of a mold, and the workpiece is pressed by a punch so that the meat of the workpiece is plastic along a shaft forming portion having a shape corresponding to the shape of the shaft portion. A shaft portion formed by flowing, and a cup portion formed at substantially the same time as the shaft portion by extruding a plastically flowing meat to the rear side in the pressing direction of the punch,
The cup portion is provided between the molding land portion and a convex portion for improving product accuracy when pressure is applied by the molding land portion of the punch, and the bending of the punch is provided. It is characterized in that an inner wall surface having a product accuracy is formed by plastically flowing while the meat of the work is corrected in the concave portion which allows for the amount.

That is, the outer ring member for a constant velocity joint according to the present invention is manufactured by a single forging process. In other words, the manufacturing time from the work to obtaining the outer ring member for a constant velocity joint is significantly shortened.

Further, for reasons to be described later, it is preferable that a taper portion having an angle of 60 ° or more and less than 90 ° is provided between the shaft portion and the cup portion.

Further, the present invention is a method of manufacturing an outer ring member for a constant velocity joint in which a shaft portion and a cup portion are integrally formed, and a chemical conversion coating film for lubrication is formed on the surface, which is a completed product. Corresponding to the shape of the shaft portion by arranging a work having a cylindrical portion having a diameter substantially equal to the outer dimension of the outer joint member for a quick joint in the cavity of the mold, and pressing the work with a punch. Front extrusion molding in which the meat of the workpiece is plastically flowed to form the shaft along the shaft molding portion of the shape, and the plastically flowing meat is extruded to the rear side in the pressing direction of the punch to form the cup portion. And a step of performing rearward extrusion molding substantially at the same time, and is provided between the molding land portion and a convex portion for producing product accuracy when a pressing force is applied by the molding land portion of the punch. The punch By plastic flow in the recess in anticipation the amount of deflection while correcting the flesh of the workpiece, and forming an internal wall surface having the product accuracy to the cup portion.

That is, according to the present invention, the cup portion is formed by using the punch in which the concave portion is formed between the molding land portion and the convex portion for improving the product accuracy in consideration of the bending amount of the punch. By doing this, the shaft portion and the cup portion having the product accuracy are formed on the workpiece by one forging process,
An outer ring member for a constant velocity joint is manufactured. Therefore, the ironing process can be eliminated.

As forging dies, only those used for this forging process may be prepared, and it is not necessary to prepare a plurality of forging dies having mutually different shapes as in the conventional case. Therefore, the manufacturing cost of the outer race member for a constant velocity joint can be reduced.

Moreover, in this case, since it is not necessary to perform the forging process a plurality of times, the low temperature annealing, the shot blasting process and the lubricating chemical conversion coating, which are performed between the forging processes in the manufacturing method according to the prior art, are performed. Need not be formed. Therefore, the outer race member for a constant velocity joint can be efficiently manufactured, so that the manufacturing cost can be further reduced.

A preferable example of the lubricating chemical conversion coating is a zinc phosphate coating, but it is not particularly limited to this and any coating that imparts lubricity to the surface of the work may be used. .

Further, it is preferable to provide a taper portion between the shaft portion and the cup portion. This is because, in this case, when the work is formed into a shape corresponding to the cavity, the meat easily plastically flows, which facilitates the forging process. In addition, in order to facilitate the plastic flow, the angle formed by the tapered portion and the axial direction of the shaft portion is set to 60 ° or more and less than 90 °.

Furthermore, it is preferable to use, as the work, a work having a protrusion on the end surface of the cylindrical portion on the side where the shaft is formed, because a finished product having a long shaft can be obtained.

In the present invention, the cup portion and the shaft portion of the outer ring member for a constant velocity joint may be formed, for example, by forming the above-mentioned lubricating conversion coating on the work and then performing cold forging. However, the work may be formed by performing a so-called warm forging process in which the temperature of the work is 400 to 800 ° C., that is, an intermediate temperature between the cold forging process and the hot forging process.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the outer ring member for a constant velocity joint according to the present invention will be described below in detail with reference to the accompanying drawings, in connection with a preferred embodiment thereof. The same components as those shown in FIGS. 9 to 12D are designated by the same reference numerals, and detailed description thereof will be omitted.

In the method for manufacturing the outer ring member for a constant velocity joint according to the present embodiment, the cold forging process is performed on the work 20 made of the carbon steel columnar body shown in FIG.
Finally, the outer ring member 1 for a tripod type constant velocity joint (see FIGS. 10 and 11) is manufactured. And the shaft portion 6
The cup portion 8 and the cup portion 8 are both formed by one cold forging process.

The diameter D of the work 20 (see FIG. 1) is set by the temperature at which cold forging is performed. That is, when the cold forging process is performed near room temperature, the work 20 hardly thermally expands. Therefore, in this case, the work 20
The diameter D may be equal to the outer diameter of the outer ring member 1 for a tripod type constant velocity joint which is a finished product. In the case of performing warm forging near the recrystallization temperature or lower, the work 2
The diameter of 0 may be set in consideration of the amount of thermal expansion. In other words, in this case, the diameter D of the work 20 is
It may be set to be slightly smaller than the outer ring member 1 for a tripod type constant velocity joint. That is, as the work 20 used in the present embodiment, a work having a larger diameter than that of the work 10 (see FIG. 12A) used in the manufacturing method according to the conventional art is selected.

Before performing cold forging on such a work 20, first, spheroidizing annealing is performed, and then a chemical conversion coating film for lubrication is formed. That is, for example, a lubricating chemical conversion coating made of zinc phosphate is formed on the surface of the work 20 to impart lubricity to the surface. Specifically, the conversion coating film for lubrication may be formed by immersing the work 20 in a solvent in which zinc phosphate is dissolved for a predetermined time.

Next, the work 20 on which the lubricating conversion coating has been formed is subjected to cold forging using the forging die device 30 shown in FIG.

Here, the structure of the forging die device 30 will be briefly described.

The forging die apparatus 30 has a first die plate 32 and a second die plate 34, and a press-fitting ring 36 formed thick on the first die plate 32.
Are fixed via a fixing member (not shown).

A cylindrical insert member 38 is fitted in the hole of the press-fitting ring 36. In addition,
The outer diameter of the insert member 38 is set to be slightly larger than the inner diameter of the press-fitting ring 36. That is, the insert member 38 is fitted into the hole portion of the press-fitting ring 36 by an interference fit.

Further, inside the insert member 38,
A lower die 40 having an axial dimension shorter than that of the insert member 38 is arranged, and the upper die 42 is disposed on the lower die 40 such that the upper end thereof is flush with the upper end of the insert member 38. Are joined. this house,
The lower die 40 is provided with a shaft forming cavity 44 for forming the shaft 6 on the work 20. Then, as shown in an enlarged manner in FIG. 3, the cavity for molding the shaft portion 4 is formed in a portion where the joint portion between the cup portion 8 and the shaft portion 6 is molded.
In order to facilitate the plastic deformation of the end surface of the work 20 press-fitted into the workpiece 4, the angle θ1 with respect to the vertical direction L is 60 ° or more 9
A tapered surface 46 that is less than 0 ° is provided.

Further, the work 20 in the lower die 40
A boss portion forming cavity 48 formed of an annular groove for forming the boss portion 7 is formed on the end surface facing the boss portion 7.
Therefore, in the lower die 40, the annular protrusion 5 is provided between the shaft forming cavity 44 and the boss forming cavity 48.
0 is provided.

A through hole 54 communicating with a hole 52 formed in the first die plate 32 is provided vertically below the shaft forming cavity 44 (see FIG. 2). In the through hole 54, a knockout pin 55 that can move up and down freely is arranged.

On the other hand, the upper die 42 has a cup portion 8
A cup portion molding cavity 56 (see FIGS. 2 and 3) for molding (see FIG. 10) is provided. The diameter of the cup portion molding cavity 56 is set to be larger than that of the shaft portion molding cavity 44.

As shown in FIG. 2, a first ring body 58 is joined to the upper end surface of the upper die 42. The first ring body 58 is provided on the upper end surface of the insert member 38.
The second ring body 60 that is fitted onto the second ring body 60 is joined to the annular recess provided in the press-fitting ring 36. .

In this case, by fastening the third ring body 62 to the press-fitting ring 36 so as to fit the second ring body 60 on the outside, the tapered surface 62a formed on the third ring body 62 becomes the second ring. Reverse taper surface 60 formed on body 60
Sliding contact with a. As a result, the first ring body 58 and the second ring body 58
A force that directs and presses the ring body 60 downward acts.

On the other hand, a hole 64 is formed in the first ring body 58, and a punch 66 is inserted in the hole 64. A guide sleeve 68 made of a metal cylindrical body is externally fitted to the side wall of the punch 66 in order to smoothly move the punch 66 up or down. Therefore, the guide sleeve 68 is interposed between the first ring body 58 and the punch 66.

Here, as shown in FIGS. 4 and 5, the tip of the punch 66 is equidistantly spaced from each other by 120 ° along the circumferential direction and along the axial direction of the punch 66. Three protrusions 70a to 70c extending with a predetermined length are provided. As will be described later, these ridges 70a
To 70c, roller grooves 9a to 9c of the cup portion 8 of the outer ring member 1 for a tripod type constant velocity joint (see FIG. 10).
Is formed. Incidentally, reference numeral 72 in FIG. 4 and FIG.
Indicates a chamfered portion formed over the entire circumference on one end side of the protruding portions 70a to 70c, that is, on the tip end surface of the punch 66.

Above the chamfered portion 72 in FIG. 5, a molding land portion 74 composed of a convex portion having a width W1 is continuously provided. The molding land portion 74 includes three ridge portions 70a ...
70c and a groove 76 between the adjacent ridges 70a to 70c
a to 76c are formed along the circumferential direction of the punch 66.

Further, a convex portion 78 having a width W2 larger than that of the molding land portion 74 is formed in an intermediate portion of the punch 66 adjacent to the guide sleeve 68. Like the molding land 74, the projection 78 also includes three protrusions 70.
It is formed along the circumferential direction of the punch 66 so as to include the a-70c and the groove portions 76a-76c.

A concave portion 80 is formed between the molding land portion 74 and the convex portion 78 for ensuring the product accuracy of the workpiece 20 when the workpiece 20 is forged by the molding land portion 74. . That is, the recess 80 is set to reduce the strain of the work 20. The recess 80 may be formed in a recessed shape of about 0.1 mm to 0.7 mm with respect to the molding land 74 and the protrusion 78, for example.

The punch 66 can be raised or lowered under the driving action of a mechanical press (not shown). That is, the ram (not shown) of this mechanical press is connected to the elevating member 82 which is displaced integrally with the ram in the vertical direction (see FIG. 2). The punch 66 is fixed to the elevating member 82 via a jig 84.

Forging die device 30 having the above-described structure
The cold forging process for the work 20 placed on the annular protrusion 50 of the lower die 40 is performed as follows.

First, the elevating member 82 connected to the ram of the mechanical press is lowered under the driving action of the mechanical press. Following this, the punch 66 descends and finally comes into contact with one end surface of the work 20.

When the punch 66 further descends, the work 2
One end surface of 0 is pressed by the punch 66. As a result, as shown in FIG.
Roller grooves 9a to 9c are formed in the axial direction of the work 20 by 0a to 70c. At the same time, the other end surface of the work 20 is press-fitted into the shaft portion molding cavity 44 and the boss portion molding cavity 48, whereby the shaft portion 6 and the boss portion 7 are formed on the other end surface. That is, at this point,
Front extrusion is performed.

During this forward extrusion molding, the shaft forming cavity 44 is provided with the tapered surface 46 forming an angle of 60 ° or more and less than 90 ° (see FIG. 3).
The other end surface of 0 easily plastically flows due to the tapered surface 46. That is, the work 20 is easily plastically deformed along the tapered surface 46, and finally reaches the limit of plastic flow to form the shaft portion 6.

The tip end surface of the shaft portion 6 thus formed abuts on the tip end surface of the knockout pin 55. In this state, as shown in FIG. 6B, when the punch 66 is further lowered, the work 2 crushed by the punch 66 is
One end surface of 0 is punched 66 while expanding by plastic flow.
Between the molding land portion 74 (see FIG. 5) and the cup portion molding cavity 56 (see FIG. 6B). That is, rearward extrusion molding is performed, whereby a thin and long cup portion 8 is formed.

At this time, the meat of the work 20 extruded by the molding land 74 flows along the recess 80 (see FIG. 5) of the punch 66, and further, the distortion of the die member with respect to the forging material. The transferred convex portion 78 corrects and holds the accuracy. That is, the shape of the work 20 is corrected, and the dimensional accuracy of the cup portion 8 including the shapes of the roller grooves 9a to 9c is ensured. That is, the work 20 is ironed.

In short, the punch 66 during the forging process
Even when the distortion of No. 1 is transferred to the work 20 by the molding land 74, the recess 80 that allows for the amount of deflection of the punch 66 corrects the accuracy of the product during molding, and finally, The convex portion 78 continuing to the concave portion 80 ensures the internal shape accuracy of the product (finished product) including the shapes of the guide grooves (roller grooves) 9a to 9c.

In other words, in the present embodiment, the work 2
By performing the front extrusion molding and the rear extrusion molding substantially simultaneously with respect to 0, the shaft portion 6 and the cup portion 8 are formed in the work 20, and the dimensional accuracy is ensured. In this process, it goes without saying that a load is applied to the knockout pin 55 from below so that the knockout pin 55 does not descend.

Finally, when the punch 66 is raised together with the ram and the elevating member 82 under the driving action of the mechanical press, the ridges 70a to 70c of the punch 66 finish the roller grooves 9a to 9c with high dimensional accuracy. Finally, when the punch 66 is removed from the first ring body 58 and then the knockout pin 55 is raised, the tripod type constant velocity joint outer ring member 1 as a finished product is exposed.

As shown in the enlarged view of FIG. 7, the cup portion 8 of the obtained outer ring member 1 for tripod type constant velocity joints.
A tapered portion 86 having a shape corresponding to the tapered surface 46 is formed between the and the shaft portion 6. That is, the angle θ2 of the taper portion 86 is 60 ° with respect to the axial direction M of the shaft portion 6.
It is not less than 90 °.

As described above, in the present embodiment, the shaft portion 6 and the cup portion 8 provided with the roller grooves 9a to 9c and having product accuracy are simultaneously formed by one forging process. Therefore, since ironing is not necessary, the outer ring member 1 for a tripod type constant velocity joint can be efficiently manufactured.

Further, since it is not necessary to perform the forging process a plurality of times, it is sufficient to prepare only the lower die 40, the upper die 42 and the punch 66 as the die for forging. That is, the number of forging dies to be prepared can be reduced as compared with the manufacturing method according to the related art. For this reason, the manufacturing cost is reduced, so that the tripod type constant velocity joint outer ring member 1 can be provided at low cost.

Further, since it is not necessary to carry out the forging process a plurality of times, the manufacturing method according to the present embodiment is such that the forging process and the tertiary molding product for producing the secondary molded product 14 in the manufacturing method according to the prior art. It is not necessary to perform low temperature annealing, shot blasting, and formation of a lubricating chemical conversion coating, which were performed during the forging process for producing 15. Therefore, the outer ring member 1 for a tripod type constant velocity joint can be efficiently manufactured. In other words, since the tripod type constant velocity joint outer ring member 1 can be mass-produced in a short time,
The manufacturing cost can be further reduced.

In the above-described embodiment, the work 20 is cold forged to form the outer ring member 1 for a tripod type constant velocity joint, but the work 20 is about 400-80.
You may make it warm to forge processing by heating at 0 degreeC.

In this embodiment, the case where the outer ring member 1 for a tripod type constant velocity joint is manufactured has been described as an example, but the present invention is not particularly limited to this, and FIG.
A ball rolling groove 90 in the cup portion 8 as shown in FIG.
It is also possible to manufacture the outer ring member 2 for a Barfield type constant velocity joint in which a and 90b are formed. The Burfield type constant velocity joint outer ring member 2 is disposed, for example, on the axle side and transmits the rotational driving force to a wheel (not shown) (see FIG. 9).

Further, the work is not particularly limited to the cylindrical body, and may have a small-diameter projection formed on the end face on the side where the shaft 6 is formed. When such a work is used, there is an advantage that a finished product having a shaft longer than the shaft 6 can be obtained.

[0062]

As described above, the outer ring member for a constant velocity joint according to the present invention has the shaft portion and the cup portion formed by one forging process. In addition, since the cup portion is a punch in which a concave portion is formed between the molding land portion and the convex portion for improving the product accuracy at the time of the forging process, the concave portion that allows the deflection amount of the punch is used, the product accuracy is improved. Therefore, ironing is not performed. Therefore, the manufacturing time from the work to obtaining the outer race member for a constant velocity joint can be remarkably shortened, and eventually the outer race member for a constant velocity joint can be efficiently manufactured.

Further, according to the method for manufacturing an outer ring member for a constant velocity joint of the present invention, a concave portion is provided between the molding land portion and the convex portion for improving the product accuracy, in consideration of the amount of bending of the punch. By molding the cup portion using the punch, the cup portion having the shaft portion and the product accuracy is formed on the work by one forging process, and the outer ring member for constant velocity joint is manufactured. That is, since the cup portion having the product accuracy is provided without performing the ironing forming, the manufacturing time until the outer ring member for a constant velocity joint is obtained is significantly shortened. In other words, the effect that the outer ring member for a constant velocity joint can be efficiently manufactured is achieved.

Further, in this case, since the work is forged only once, it is not necessary to prepare a plurality of forging dies having different shapes. Therefore, the manufacturing cost of the outer race member for a constant velocity joint can be reduced.

Further, when the work is cold forged by this manufacturing method, the annealing, the shot blasting, and the formation of the lubricating chemical conversion coating may be performed once before the forging. That is, according to the method for manufacturing an outer ring member for a constant velocity joint according to the present invention, the number of times of forging processing itself can be reduced,
Moreover, it is possible to reduce the number of times of various types of processing performed on the work. Therefore, the outer ring member for a constant velocity joint can be manufactured more efficiently, and the manufacturing cost of the outer ring member for a constant velocity joint can be further reduced.

[Brief description of drawings]

FIG. 1 is a schematic overall perspective view of a work used as a raw material for an outer ring member for a tripod type constant velocity joint in the present embodiment.

FIG. 2 is a schematic vertical cross-sectional view of a forging die device that performs a method for manufacturing an outer ring member for a constant velocity joint according to an embodiment of the present invention.

FIG. 3 is an enlarged vertical sectional view of essential parts of a lower die and an upper die that constitute the forging die device of FIG.

4 is a schematic overall perspective view of a punch constituting the forging die device of FIG. 2. FIG.

5 is a schematic front view of the punch of FIG.

6A and 6B are schematic vertical cross-sectional views of a main part showing a process in which a punch descends and a shaft portion and a cup portion are molded.

FIG. 7 is an enlarged vertical cross-sectional view of a main part of the obtained outer ring member for a tripod type constant velocity joint.

FIG. 8 is a partially cutaway sectional view of an outer ring member for a Burfield type constant velocity joint.

FIG. 9 is a schematic configuration diagram of a driving force transmission mechanism configured by connecting four outer ring members for constant velocity joints to a spline shaft.

FIG. 10 is a partially cutaway sectional view of an outer ring member for a tripod type constant velocity joint.

11 is a schematic front view of the outer ring member for the tripod type constant velocity joint of FIG.

FIG. 12A to FIG. 12D are explanatory views showing the steps of the forging process on the work.

[Explanation of symbols]

1, 2 ... Outer ring member for constant velocity joint 6 ... Shaft portion 8 ... Cup portion 9a-9
c ... Roller groove 10, 20 ... Work piece 30 ... Forging die device 40, 42 ... Die 44 ... Shaft part forming cavity 46 ... Tapered surface 55 ... Knockout pin 56 ... Cup part forming cavity 66 ... Punches 70a-70c. Ridge portion 74 ... Molded land portions 76a to 76c ... Groove portion 78 ... Convex portion 80 ... Recessed portion 82 ... Elevating member 86 ... Tapered portion 90a,
90b ... Ball rolling groove

Claims (6)

[Claims] 1. A work having a conversion coating film for lubrication formed on its surface and having a cylindrical portion having a diameter substantially equal to the outer dimension of the outer ring member for a constant velocity joint which is a finished product is placed in a cavity of a mold, Is pressed by a punch, the shaft portion formed by plastically flowing the meat of the work along the shaft forming portion having a shape corresponding to the shape of the shaft portion, and the plastically flowing meat And a cup portion that is formed substantially at the same time as the shaft portion by being pushed out to the rear side in the pressurizing direction, and when a pressing force is applied to the cup portion by the molding land portion of the punch, An inner wall surface having product accuracy by plastically flowing while the meat of the workpiece is corrected by a recessed portion provided between the molding land portion and a convex portion for producing product accuracy and allowing for the deflection amount of the punch. Is formed A constant velocity joint outer ring member, wherein. 2. The outer ring member for a constant velocity joint according to claim 1, wherein a taper portion is provided between the shaft portion and the cup portion, and an angle formed by the taper portion and an axial direction of the shaft portion. Is 60 ° or more and less than 90 °, an outer ring member for a constant velocity joint. 3. A method for manufacturing an outer race member for a constant velocity joint, wherein a shaft portion and a cup portion are integrally formed, wherein a chemical conversion coating for lubrication is formed on the surface of the outer race member for a constant velocity joint. A step of arranging a work having a cylindrical portion having a diameter substantially equal to the outer dimension of the member in the cavity of the mold; and a shaft portion having a shape corresponding to the shape of the shaft portion by pressing the work with a punch. Front extrusion forming the shaft portion by plastically flowing the meat of the work along the forming portion, and rear extrusion forming the cup portion by extruding the plastically flowing meat rearward in the pressing direction of the punch. And the step of performing substantially the same at the same time, and when the pressurizing force is applied by the molding land portion of the punch, the punching portion is provided between the molding land portion and the convex portion for improving product accuracy. See the amount of deflection A method for manufacturing an outer ring member for a constant velocity joint, characterized in that an inner wall surface having product accuracy is formed in the cup portion by causing plastic flow while correcting the meat of the work in the recessed portion. 4. The manufacturing method according to claim 3, wherein a taper portion is provided between the shaft portion and the cup portion, and an angle formed by the taper portion and the axial direction of the shaft portion is 60 ° or more and 90 or more. A method for manufacturing an outer ring member for a constant velocity joint, which is characterized in that it is less than °. 5. The manufacturing method according to claim 3 or 4, wherein as the work, a work having a projection on an end surface of the cylindrical portion where the shaft is formed is used. Manufacturing method of outer ring member for joint. 6. The manufacturing method according to claim 3, wherein the temperature of the work on which the conversion coating for lubrication is formed is set to 400 to 800 ° C., and the front extrusion and the rear extrusion are performed. A method for manufacturing an outer ring member for a constant velocity joint, which is characterized in that