WO2006137198A1

WO2006137198A1 - Method for producing outer ring member of constant velocity universal joint

Info

Publication number: WO2006137198A1
Application number: PCT/JP2006/305881
Authority: WO
Inventors: Yoshihisa Doi
Original assignee: Honda Motor Co., Ltd.
Priority date: 2005-06-21
Filing date: 2006-03-23
Publication date: 2006-12-28
Also published as: US20090133262A1; JP2007000873A

Abstract

A primary product (40) is formed by performing forward extrusion of a work (10) in the first step, and a secondary product (50) is formed by performing swaging in the second step. In the third step, preliminary pushing of the upper surface of the secondary product (50) is performed to obtain a tertiary product (60) where a recess (62) generally matching the longitudinal section in the axial direction of the bottom wall (32) of a cup portion (16) of the final product is formed in the upper surface. In the fourth step, a quaternary product (70) having a cup portion provided with a ball rolling groove (74) in the inner wall is formed by performing backward extrusion of the tertiary product (60) by using a punch having a tip shape generally matching the longitudinal section of the recess (62). Finally, in the fifth step, an outer ring member (12) is produced as a final product by performing ironing of the cup portion of the quaternary product (70).

Description

Specification

Manufacturing method of outer ring member for constant velocity joint

Technical field

The present invention relates to an outer ring member for a constant velocity joint that constitutes a constant velocity joint for transmitting rotational driving force, and more specifically, a cup portion and a shaft portion having a plurality of guide grooves on an inner peripheral surface. The present invention relates to a method for manufacturing an outer ring member for a constant velocity joint, in which an outer ring member for a constant velocity joint formed in a body is manufactured by forging.

Background art

Conventionally, a forging material is loaded into a cavity formed on an upper die and a lower die joined together, and pressure is applied to the forging material via a punch. The outer ring member (outer cup) of the constant velocity joint for driving the wheel is manufactured.

[0003] The outer ring member includes a cup portion and a shaft portion formed integrally with the cup portion. A plurality of ball rolling grooves extending along the axial direction are formed on the inner peripheral surface of the cup portion so as to be spaced apart at equal angles along the circumferential direction, and the balls are formed along the ball rolling grooves. Is provided to roll.

[0004] As a method for manufacturing an outer ring member of this type of constant velocity joint, Patent Document 1 discloses that a recess having a semicircular cross section is formed on the upper surface of a cup portion by performing upset molding on a preform. Is disclosed. In this case, in Patent Document 1, it is assumed that by forming a recess having a radial cross section on the upper surface of the cup portion, the plastic fluidity at the time of backward extrusion molding in the next process becomes smooth, and the product completion accuracy can be improved. Yes.

[0005] Further, Patent Document 2 discloses that a concave hole is formed in the upper surface of the head by subjecting the hot-treatment material having the head and the body to front and rear extrusion. ing.

[0006] Further, Patent Document 3 discloses forming a concave cave portion by pressing the center portion of the end surface of the large diameter portion.

However, in the technical ideas disclosed in Patent Documents 1 to 3, the following steps are used in the technical idea. For example, a force that forms a recess in the head of the intermediate molded body only to smooth the meat flow when performing the rear extrusion, and the ball rolling groove is formed on the inner wall surface of the cup portion by the rear extrusion. The amount of work (molding rate) increases compared to other processes where the amount of deformation (elongation of material) in the forming process is still large.

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-178090

Patent Document 2: JP-A-58-50149

Patent Document 3: Japanese Patent Application Laid-Open No. 55-5120

Disclosure of the invention

[0009] A general object of the present invention is to share a part of the work amount in the fourth step with the third step, which is the previous step, to reduce the molding rate in the fourth step of forming the ball rolling groove. Another object of the present invention is to provide a method of manufacturing an outer ring member for a constant velocity joint that can achieve optimum dispersion in each process.

The present invention performs the following first to fifth steps.

[0011] First, in the first step, a primary molded body having a shaft portion is formed by subjecting a cylindrical workpiece cut to a predetermined length to forward extrusion molding.

[0012] Subsequently, in the second step, upset molding is performed on the upper portion excluding the shaft portion, and a secondary molded body in which the upper portion of the primary molded body is compressed and expanded is formed. To do.

[0013] Subsequently, in the third step, the upper surface of the secondary molded body is subjected to pre-indentation molding so that the vertical cross-sectional shape in the axial direction of the bottom wall of the cup portion of the final product is substantially the same. A third molded body is formed in which matching concave portions are formed on the upper surface. Originally, the bottom wall of the cup portion is obtained by sharing the third step with the fourth step which is the next step.

[0014] In this case, an R portion having a curved cross section is formed along the circumferential direction at the boundary portion between the upper surface of the head of the third molded body and the opening of the recess, so that the recess It is possible to prevent streaks from occurring around the opening.

Subsequently, in the fourth step, a ball having a tip formed on the inner wall is formed by subjecting the third molded body to a rear extrusion by using a punch having a tip shape that substantially matches the longitudinal sectional shape of the recess. A fourth molded body having a cup portion provided with rolling grooves is formed. [0016] Finally, in the fifth step, a bar field mold in which the shaft portion and the cup portion, which is the final product, is formed by ironing the cup portion of the fourth molded body, is formed as a whole. The outer ring member for constant velocity joint is manufactured.

[0017] According to the present invention, a part of the work of forming the bottom wall of the cup portion in the fourth step is shared with the third step, which is the previous step, to form the ball rolling groove. Process formation rate can be reduced.

As a result, in the present invention, by reducing the forming rate in the fourth step, the deformation amount (elongation of the material) of the forging material is reduced, and the occurrence of material cracking is avoided and good mold transferability is achieved. Can be achieved.

Brief Description of Drawings

FIG. 1 is a flowchart showing a manufacturing process of a constant velocity joint outer ring member according to the present embodiment.

[FIG. 2] FIGS. 2A to 2F are a side view and a partial longitudinal sectional view showing the shape of an outer ring member for a constant velocity joint, which is a finished product by forging a workpiece along the manufacturing process shown in FIG. FIG.

FIG. 3 is a longitudinal sectional view along the axial direction of a constant velocity joint outer ring member which is a finished product.

FIG. 4 is an arrow view seen from the direction of arrow Z in FIG.

FIG. 5 is a partially enlarged side view of the ball rolling groove shown in FIG.

FIG. 6 is a partially enlarged side view of an R portion formed at a boundary portion between the concave portion and the upper surface of the third molded body shown in FIG. 2D.

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] In the method for manufacturing an outer ring member for a constant velocity joint according to the present embodiment, as shown in the flow chart of Fig. 1, a workpiece 10 having a carbon steel cylindrical body (billet) force (see Fig. 2A) In total, forging is performed five times, and finally the finished Barfield type constant velocity joint outer ring member 12 (hereinafter simply referred to as the outer ring member 12) is manufactured.

As shown in FIGS. 3 and 4, the outer ring member 12 is connected to one end portion of a shaft (not shown) and has a bottomed cylindrical cup portion 16 having an opening portion 14, and the cup portion 16. It is basically composed of a shaft part 18 formed integrally. [0022] The outer surface of the cup portion 16 adjacent to the connection portion between the cup portion 16 and the shaft portion 18 has a longitudinal section along the axial direction extending from the side peripheral portion 20 substantially parallel to the axis to the shaft portion 18 side. A curved surface portion 22 that is reduced in diameter while being curved in an arcuate shape is formed, and is connected to the shaft portion 18 via an annular stepped portion 24 that continues to the curved surface portion 22 and extends in a direction perpendicular to the axis. It is configured as follows.

[0023] On the inner wall surface of the cup portion 16 of the outer ring member 12, an inner diameter surface 28 that also has a spherical force bulges toward the center side, and extends along the axial direction between adjacent inner diameter surfaces 28. A plurality of existing ball rolling grooves 30a to 30f are formed around the shaft center at intervals of 60 degrees (see FIGS. 3 and 4).

[0024] The ball rolling grooves 30a to 30f smoothly roll a ball (not shown), and extend along the inner wall surface of the outer ring member 12 to the vicinity of the end portion on the bottom side of the cup portion 16. Provided. Further, as shown in FIG. 5, each of the ball rolling grooves 30a to 30f has a cross-sectional arc shape having a single radius of curvature when viewed from the axial direction of the outer ring member 12 (the arrow Z direction in FIG. 3). It is formed.

Furthermore, a bottom wall 32 (see an imaginary line F1 in FIG. 3) formed at the innermost wall surface of the cup portion 16 of the outer ring member 12 and extending in a direction perpendicular to the axial direction is the cup portion. 16 is set at an intermediate position of the curved surface portion 22 formed on the outer surface, and is set so as to be separated by Δ P along the imaginary line F2 of the annular step portion 24 continuous with the curved surface portion 22 along the axial direction ( (See Figure 3).

[0026] The vertical cross-sectional shape along the axial direction of the bottom wall 32 formed in the cup portion 16 includes a circular flat surface 33 having a diameter D3 in plan view, and from the circular flat surface 33 to the opening. It is constituted by an annular inclined surface 35 having a continuous inclination angle with respect to the circular flat surface 33 of Θ3, and as will be described later, the concave portion 62 of the third molded body 60 and the bottom wall 76 of the fourth molded body 70. Is substantially the same as the vertical cross-sectional shape.

[0027] The outer ring member 12 is manufactured by the following process.

[0028] First, in the first preparation step, spheroidizing annealing is performed on the workpiece 10 (see FIG. 2A) cut into a cylindrical body (billet) having a predetermined length. As a result, the workpiece 10 is softened and the following first to fifth forging processes are facilitated. Then, in the second preparation step, a chemical conversion coating for lubrication is formed on the workpiece 10. In other words, for example, by forming a chemical conversion coating for lubrication having the same strength as zinc phosphate on the surface of the workpiece 10 by bonderite treatment, lubricity is imparted to the surface. Specifically, the chemical conversion coating for lubrication should be formed by immersing the workpiece 10 in a solvent in which zinc phosphate or the like is dissolved for a predetermined time.

[0030] Next, in the first forging step S1, forward extrusion molding is performed on one end surface of the workpiece 10 on which the chemical conversion coating for lubrication is formed, using a first forging die (not shown).

That is, the workpiece 10 is loaded into the cavity of a first forging die (not shown), and one end surface of the workpiece 10 is pressed by a punch (not shown). Along with this, the other end surface side of the workpiece 10 is press-fitted into the cavity, and as a result, as shown in FIG. 2B, a reduced diameter portion 40a and a shaft portion 40b that are reduced in taper shape on the other end surface side are formed. The formed primary molded body 40 is obtained (see FIG. 2B).

[0032] Next, upsetting is performed on the primary compact 40 in the secondary forging step S2. That is, the primary molded body 40 is loaded into the cavity of a second forging die (not shown). At this time, the shaft portion 40b is inserted into a shaft portion holding portion (not shown) provided in the second forging die.

Then, although not shown, the tip of the shaft portion 40b inserted into the shaft portion holding portion is not shown, and the upper portion of the primary molded body 40 is pressed with a punch while being supported by a pressing member. Crush. Along with this crushing, the upper part is compressed in the vertical direction and expanded in the horizontal direction, whereby a secondary molded body 50 (see FIG. 2C) is obtained.

[0034] Subsequently, in the third forging / casing step S3, preliminary pressing is performed on the upper surface of the head of the secondary molded body 50, and a recess 62 is formed at the center of the upper surface of the head. The obtained third molded body 60 is obtained (see FIG. 2D).

That is, by using a third forging die (not shown) and pressing the upper surface of the secondary molded body 50 loaded in the cavity with a punch (not shown), the head of the secondary molded body 50 is pressed. A recess 62 is formed in which the central portion of the upper surface is recessed by a predetermined depth in the axial direction.

[0036] As shown in FIG. 6, the recess 62 is a circle having a diameter D1 (see FIG. 2D) in plan view. The shape flat surface 64 and an annular inclined surface 66 that is continuous from the circular flat surface 64 to the opening and that has an inclination angle θ 1 with respect to the circular flat surface 64.

[0037] It should be noted that the predetermined depth T1 (see FIG. 2D) of the recess 62 is such that the circular flat surface 72 and the ball rolling groove formed at the back of the cup portion of the fourth molded body 70 in the next step. It should be set to be less than the separation distance T2 (see Fig. 2E) along the axial direction (vertical direction) with the rear end of 74 (側 1≤Τ2).

[0038] In the third molded body 60, the vertical cross-sectional shape of the concave portion 62 constituted by the circular flat surface 64 and the annular inclined surface 66 is a cut in the fourth molded body 70 of the next step. The bottom wall 76 formed in the inner part of the bottom portion is substantially the same as the vertical cross-sectional shape of the bottom wall 76, and the force is substantially the same as the vertical cross-sectional shape along the axial direction of the bottom wall 32 of the outer ring member 12 that is the final product. Configured.

[0039] Further, an R portion 68 having a non-angular shape and a curved cross section having a predetermined radius of curvature is provided around the boundary portion between the upper surface of the head of the third molded body 60 and the opening of the recess 62. It is formed along the direction (see Fig. 6).

[0040] By forming the R portion 68 in the entrance portion where the recess 62 is opened, it is possible to prevent the generation of streaks around the opening portion of the recess 62, and in the subsequent step, the third order When heat treatment is performed on the molded body 60, it is possible to avoid the occurrence of cracks due to the streaks.

[0041] After the third forging step S3 is completed, low temperature annealing to remove stress from the third compact 60, shot blasting to remove oxide scales, etc. generated during this low temperature annealing, bonderite A chemical conversion coating for lubrication having the same strength as zinc phosphate is formed on the outer surface of the tertiary compact 60 by the treatment. By performing these various treatments, the third molded body 60 can be easily plastically deformed.

[0042] Thereafter, a fourth forging step S4 is performed using a fourth forging die (not shown). For the third molded body 60 in which the shaft portion is inserted into the shaft insertion portion of the fourth forging die not shown, the tip shape is substantially the same as the longitudinal sectional shape of the recess 62 of the third molded body 60. A fourth forged body 70 is obtained by performing a fourth forging process using a punch not shown in the figure (see FIG. 2). [0043] In this case, the vertical cross-sectional shape of the bottom wall 76 formed in the inner part of the cup portion of the fourth molded body 70 includes a circular flat surface 72 having a diameter D2 in plan view, and the circular flat surface. An annular inclined surface 78 that is continuous from the surface 72 to the opening and has an inclination angle of Θ2 with respect to the circular flat surface 72 is substantially the same as the longitudinal sectional shape of the recess 62 of the third molded body 60 as described above. It is the same.

[0044] In the fourth forging step S4, the third formed body 60 is performed using a punch (not shown) whose tip shape is substantially the same as the longitudinal sectional shape of the recess 62 of the third formed body 60. Therefore, the circular flat surface 64 constituting the recess 62 becomes a non-plastic flow site, and only the annular inclined surface 66 becomes a plastic flow site and is pushed out rearward of the cup portion.

[0045] After the fourth forging step S4, the fifth cold forging step S5 is performed on the fourth compact 70. Before performing the fifth forging step S5, a liquid lubricant may be applied to at least one of the surface of the fourth compact 70 and the fifth forging die (not shown). Thereby, it is possible to avoid the seizure of the fourth compact 70 or the fifth forging die during the fifth forging / casing step S5. As the liquid lubricant, a known liquid lubricant that has been used in the past can be used.

[0046] In the fifth forging step S5, a fifth forging die (not shown) is used, and the force and tip shape are substantially the same as the longitudinal sectional shape of the recess 62 of the third molded body 60 (not shown). Using a punch, ironing (final sizing) is performed on the inner and outer surfaces of the fourth molded body 70 to finish the cup portion 16 into a final product shape.

[0047] That is, the thickness of the cup portion 16 and the width and depth of the ball rolling grooves 30a to 30f are processed so as to have a predetermined dimensional accuracy, thereby forming the shapes of the ball rolling grooves 30a to 30f and the like. As a result, an outer ring member 12 for a Barfield type constant velocity joint is obtained as a finished product with a dimensional accuracy of the cup portion 16 including (see FIG. 2F).

[0048] When the fifth forging step S5 is performed on the fourth compact 70, the circular flat surface 72 constituting the bottom wall 76 of the cup portion becomes a non-plastic flow portion, and the annular inclined surface 78 Only the plastic flow part becomes sizing.

[0049] The vertical cross-sectional shape of the bottom wall 32 formed in the inner part of the cup portion 16 of the outer ring member 12 has a circular flat surface 33 having a diameter D3 in plan view and an opening from the circular flat surface 33. To the department Continuing, it is constituted by an annular inclined surface 35 having an inclination angle of Θ3 with respect to the circular flat surface 33, and is substantially the same as the longitudinal sectional shape of the concave portion 62 of the third molded body 60 and the bottom wall of the fourth molded body 70. It is.

[0050] In other words, the diameters of the circular flat surfaces 64, 72, 33 from the third molded body to the fifth molded body (the outer ring member 12 as the final product) are D1 ^ D2 ^ D3, and The angle of inclination of the annular inclined surfaces 66, 78, 35 with respect to the circular flat surfaces 64, 72, 33 is Θ 1 = Θ 2 = Θ 3. It is preferable that the inclination angle of each annular inclined surface 66, 78, 35 is set to about 45 degrees.

[0051] In this case, as forging, the first forging process S1 to the third forging process S3 are performed by warm forging or hot forging! The fifth forging process S5 may be performed by cold forging. Alternatively, all the steps from the first forging caloing step S1 to the fifth forging step S5 can be performed by cold forging.

[0052] According to the present embodiment, a part of the work of originally forming the bottom wall of the cup part in the fourth forging step S4 is transferred to the third forging step S3, which is the previous step. By forming the concave portion 62 on the upper surface of the third molded body 60 by sharing it, the molding rate in the fourth forging step S4 for forming the ball rolling grooves 30a to 30f can be reduced.

As a result, in the present embodiment, by reducing the forming rate in the fourth forging step S4, the deformation amount (elongation of material) of the forging material is reduced, and the occurrence of material cracking is avoided. And good mold transferability can be achieved.

[0054] Further, in the present embodiment, the circular flat surface of the recess 62 formed in the third molded body 60 becomes a non-plastic flow site, and the plastic flow site force is removed, so that the fourth forging process is performed. In the process and the fifth forging process, the plastic flow (meat flow) when forming the ball rolling grooves 74 and 30a to 30f becomes smoother, and the ball rolling grooves 74 and 30a to 30f are formed with high accuracy. can do.

[0055] Furthermore, in this embodiment, the ball rolling groove 74 is formed by sharing a part of the work amount in the fourth forging process to the third forging process, which is the previous process. Reduce the forming rate of the fourth forging process to achieve optimal dispersion of each process Can do. As a result, the yield can be improved by suppressing the occurrence of defective products such as material cracks.

Claims

The scope of the claims

[1] A method of manufacturing an outer ring member (12) for a bar-field constant velocity joint in which a shaft portion (18) and a cup portion (16) are integrally formed by forging,

A first step of forming a primary molded body (40) having a shaft portion (40b) by forward-extrusion molding a cylindrical workpiece (10) cut to a predetermined length; and

By performing upset molding on the upper part excluding the shaft part (40b), the upper part of the primary molded body (40) is compressed and expanded in diameter to form the secondary molded body (50). The second step to be formed and the top surface of the secondary molded body (50) are subjected to preliminary indentation, whereby the longitudinal section in the axial direction of the bottom wall (32) of the cup portion (16) of the final product is formed. A third step of forming a third molded body (60) in which a concave portion (62) substantially matching the surface shape is formed on the upper surface; and a tip portion shape substantially matching the vertical sectional shape of the concave portion (62) A fourth molded body (70) having a cup portion provided with a ball rolling groove (74) on the inner wall by subjecting the third molded body (60) to rear extrusion by using a punch having And a fifth step of performing ironing forming on the cup portion of the fourth molded body (70). Manufacturing method for outer ring member.

[2] In the manufacturing method according to claim 1,

An R portion (68) having a curved cross section is formed along the circumferential direction at a boundary portion between the upper surface of the head of the third molded body (60) and the opening of the recess (62). A method of manufacturing a characteristic outer ring member for constant velocity joint.

[3] In the manufacturing method according to claim 1,

The concave portion (62) of the third molded body (60) has a circular flat surface (64) having a diameter D1 in plan view and the circular flat surface (64) force continuous to the opening. A method of manufacturing an outer ring member for constant velocity joint, comprising: an annular inclined surface (66) having an inclination angle of θ 1 with respect to the flat surface (64).

[4] In the manufacturing method according to claim 3,

The vertical cross-sectional shape of the bottom wall (76) formed at the back of the cup portion of the fourth molded body (70) is a circular flat surface (72) having a diameter D2 in plan view, and the circular shape Open from flat surface (72) An annular inclined surface (78) that continues to the mouth and has an inclination angle of Θ 2 with respect to the circular flat surface (72), and a longitudinal sectional shape of the recess (62) of the tertiary molded body (60) Method for producing an outer ring member for a constant velocity joint, characterized in that the outer ring member is provided substantially at the same position (Dl ^ D2, Θ 1 = Θ 2)

[5] In the manufacturing method according to claim 4,

The vertical cross-sectional shape of the bottom wall (32) formed at the back of the cup portion (16) of the outer ring member (12) is a circular flat surface (33) having a diameter D3 in plan view, and the circular shape An annular inclined surface (35) that is continuous from the flat surface (33) to the opening and has an inclination angle of Θ3 with respect to the circular flat surface (33), and a recess ( 62) and the constant-velocity characterized by being provided with substantially the same vertical cross-sectional shape (D1 D2 D3, Θ 1 = Θ 2 = Θ 3) of the bottom wall (76) of the fourth compact (70). Manufacturing method of outer ring member for joint.

[6] In the manufacturing method according to claim 1,

The depth T1 along the axial direction of the recess (62) of the third molded body (60) is a circular flat surface (72) formed at the back of the cup portion of the fourth molded body (70). ) And the rear end portion of the ball rolling groove (74) is set to a separation distance T2 or less (T1≤T2) along the axial direction.