JPS62104644A - Manufacture of yoke universal joint having shank - Google Patents

Abstract

PURPOSE:To obtain a yoke provided with a shank, which generates no burr and has a high strength, by constituting it so that a coarse arm part can be elongated and formed by crushing and pressing a coarse yoke part of a coarse forming member by a punch having an upper slanting forming surface, in an arm elongating process. CONSTITUTION:In a preforming process, a coarse forming member 15 consisting of a coarse shank 16 and a coarse yoke part 17 is brought to a cold extrusion forming. In an arm elongating process, the coarse yoke part 17 is crushed and pressed by a punch P having a wedge-shaped forming part A of a radius R, a receiving hole 26 for inserting through the coarse shank 16, a recessed part 27 for forming a coarse base part 20, and a die having a forming surface 28 of an angle alpha in the X direction of the right and left. A preforming member 19 by which a coarse arm part 21 has been elongated and formed in the X direction is subjected to crush-forming of the coarse base part 20, and bending and iron-forming of the coarse arm part 21, and becomes a yoke member 30 having an arm 7. In this way, a yoke provided with a shank, which generates no burr and has a high strength can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a yoke for a universal joint having a shaft portion.

(Prior art) Conventionally, there is a method for manufacturing this type of universal joint yoke, for example, as disclosed in Japanese Patent Publication No. 60-8128. U for universal joint
In a method for manufacturing a character-shaped yoke, a blank is used in which both ends of the side to be bent into a U-shape are formed in advance into an arc shape in the width direction, and both longitudinal ends are formed into predetermined inclined surfaces. Using a die formed into a shape corresponding to the outer peripheral surface of the yoke, the width is shorter than the length of the side to be bent into a U-shape of the blank, and the outer shape corresponds to the inner peripheral surface of the yoke. Using a punch having convex portions facing each other on the sides, the blank placed in the die is punched in the center of the yoke so as not to come into contact with the parts corresponding to both arms of the yoke. Pressing is performed while they are in contact with each other, so that the pair of inclined surfaces are arranged on the same plane and form the top surfaces of both arms of the yoke.
Further, a yoke having four joint introduction portions is formed on the inner wall surfaces of both arm portions.

(Problem to be Solved) Therefore, in the method for manufacturing a yoke for a universal joint by cold forging described above (because the stray arm part is formed by backward extrusion into an irregular shape, the cross section when forming the arm part The reduction rate is high at around 75%, and the external molding force during this molding is more than 80% of the crushing load of the mold, so the elastic deformation of the mold becomes large and cracks occur from the area where the die and punch meet. do.

■The life of the mold will be shortened.

In addition, the yoke according to this conventional method has problems such as that it is difficult to ensure stable strength because the shaft for transmitting rotational motion must be joined by welding means or the like.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned conventional problems, and by adopting a molding process in which the processing surface pressure of each molding process is reduced, ■ the generation of paris; It is possible to mold the yoke without any problems.

■Mold life can be significantly improved.

■Product strength can be improved through effective use of fiber flow and work hardening.

■It is possible to improve the strength of the connection between the yoke and the shaft by integrally molding the shaft for transmitting rotational motion with the yoke.

The purpose is to provide a method for manufacturing a yoke for a universal joint with the shaft part on the right, the first gist of which is to provide a yoke base perpendicular to the axis of the coaxial part at one end of the shaft part, and a yoke base that is perpendicular to the axis of the coaxial part, and a A method for manufacturing a yoke member integrally equipped with a pair of arms extending in a direction opposite to the yoke member, the method comprising: (a> a material taking step of taking a material having a volume substantially equal to the entire volume of the yoke member; (b) a T-preparation step in which the raw material is cold-formed to form a roughly formed member consisting of a rough shaft portion and a rough yoke portion; (c) a T-preparation step in which the rough yoke portion of the rough formed member is crushed and formed; (d) an arm extending step of forming a preformed member by extending the rough arm portions to the left and right of the rough base; and (d) bending the rough arm portions by crushing and forming the rough base portion of the preformed member; and a step of bending and ironing the preformed member to a predetermined width and thickness to form a rough base and a rough arm into an arm consisting of a yoke base and an arm. In the arm extension process, a receiving hole is provided into which the rough shaft portion of the rough-formed member is inserted, and the axis of the receiving hole is set in seven directions, and an upper peel-shaped piece is inserted at a predetermined angle in the X direction of the axis. A die with a molding surface facing to the right and forming four parts forming a rough base that will become the yaw 91 part at the end of the receiving hole, and a die having a substantially wedge-shaped cross section in the X direction with respect to the axis of the receiving hole and having a predetermined diameter at the tip. A rough yoke portion of the rough formed member is formed by a bunch having a forming portion and having an upwardly peeled forming surface at a predetermined angle in the X direction in correspondence with the forming surface of the die, continuous with the forming portion. A method for manufacturing a yoke for universal joins 1 to 1 having a shaft portion characterized in that the rough arm portion is extended and formed in the X direction by crushing and pressing, and the second gist is (a) (b) cold-forming the material to form a rough-formed member consisting of a rough shaft portion and a rough yoke portion; a pre-flG forming step, and (c) arm extension in which the rough yoke portion of the rough formed member is crushed and molded to form a rough base portion having an extra thickness portion, and a rough arm portion is extended to the left and right to form a preformed member. (d) an arm bending step of forming a yoke base by crushing the rough base having the excess thickness of the rough formed member and bending the rough arm; (e) bending the rough arm.・
It consists of an arm bending process of ironing and forming the preshaft part into a predetermined width and thickness, and in particular, in the arm bending process, a receiving hole is formed through the die into which the preshaft part of the preformed member is inserted. do,
A mold hole for molding the yoke base is formed at the end of the same hole (), a bunch is arranged on the axis of the mold hole, and the rough base is crushed and pressed to form the yoke base. Along with
The present invention provides a method for manufacturing a yoke for a universal joint having a shaft portion, characterized in that the rough arm portions are bent and formed into a nearly opposing shape by crushing the excess thickness by this crushing pressure.

(Example) Next, one embodiment of the present invention will be described with reference to the drawings.

1 and 2 show a specific example of a universal reel joint yoke 1 having a shaft portion according to the present invention (hereinafter referred to as a yoke with a shaft portion). 2 and a yoke portion 4° are integrally formed, and a serration portion 3 is formed on the outer periphery of the end side of the shaft portion 2 over a predetermined range to be connected to other parts and to transmit 1 to 1 torque. . Note that this shaft portion 2 has a predetermined length L and is formed to have an outer diameter d. Reference numeral 5 denotes a yoke base of the yoke portion 4, which has a predetermined wall thickness and is formed into a circular shape with a predetermined diameter. A circular reinforcing thick portion 6 having a wall thickness t2 is integrally formed. Further, in the diametrical direction of the yoke base 5, a pair of arms 7 which are parallel to the axis of the shaft 2 and have an equal length of 1'' are formed to extend in the opposite direction from the shaft 2 with a predetermined width S. It is formed to have a rotational diameter R. Further, a hole 9 for holding a bearing is formed in a corresponding hole E'-12 at a predetermined position neck on the distal end side of the arm 7. The yoke 1 with a shaft portion of this example formed in this manner is rotatably connected to a mating yoke 10 via a cross shaft 11 and a needle bearing 12, so that one yoke can be moved from one yoke to the other. It is said that torque can be transmitted with a moving angle. Note that 13 is a sealing member.

Next, a method for manufacturing the shaft-equipped yoke 1 configured as described above by cold forging will be described. The processing processes using this cold forging include (1) material removal process, (2)
) Preforming step of forming the rough formed member 15, (3) Arm extension step of forming the rough formed member 15 into the preformed member 19, (4) Arm bending step of forming the preformed member 3゛O into a yoke member. It depends on the process.

Reference numeral 14 is a material for cold forging, which is obtained by cutting a round steel bar with a predetermined diameter D1 into a predetermined length hl in the material removal process. The material is taken in a volume sufficient to integrally mold the yoke part 4. The material 14 thus obtained is cold forged into a roughly formed member 15 shown in FIG. 5 in a preforming step.

In this preforming step, the material 14 is cold extruded to form a rough formed member 15 consisting of a rough shaft portion 16 and a roughly cylindrical rough yoke portion 17, and the rough shaft portion 16 has a diameter d1. , length jl, and the rough yoke portion 17 has a diameter D
2 is formed to have a length h2, and at the junction between the in-phase shaft portion 16 and the coarse yoke portion 17, the oblique, substantially conical portion 18 is formed. Further, the volume of the rough yoke portion 17 is formed to a volume that forms part of the yoke portion 4 and the shaft portion 2. The rough molded member 15 formed in this way has the rough yoke portion 1
7 is cold crushed and formed by a bunch P to form a preformed member 1
It is molded into 9.

In this arm extension step, the roughly cylindrical rough yoke portion 17 of the rough formed member 15 is cold crushed and formed into a rough base portion 20.
While forming the rough arm part 21, a part of it is
The roughly cylindrical rough yoke portion 17 is generally formed into an irregular shape by cold punching and forming into the child shaft portion 22 with the rough shaft portion 16. As shown in the figure and FIG. 10, the bunch P has a substantially wedge-shaped molded part A with a radius R at the tip and a receiving hole 26 through which the coarse shaft part 16 is inserted into the medium heat, and the upper part of the receiving hole 26. It has a recess 27 for forming the rough base 20, and a receiving hole 26.
Bunch P
When the material is crushed and pressed along the axis of the coarse shaft portion 16, a forming force Px is generated in the coarse yoke portion 17 due to the wedge effect of the bunch P, which tends to cause the material to flow in the X direction shown in the figure.
The forming force Py in the Y direction is extremely small, so the crushing width W (width in the X direction) is formed larger than the width WO in the Y direction, and the rough arm portion 21 in this example is formed. Illustrated lower surface of portion 21 (convex curved surface 8)
The 23 side is molded at an angle α to the molding surface 28, and the illustrated upper surface 24 is formed by extending at an angle β to the molding surface 28 of the die 25 due to the material of the blank 14 and the radius R to the molding part of the bunch P. Ru. Therefore, in this arm extension process, the rough shaft portion 16 of the rough formed member 15 is inserted into the receiving hole 25 in the die 25.
The cone 18 is inserted into the recess 27, and the rough yoke 17 is erected concentrically with the center line of the receiving hole 26. Thus, the bunch P is pressed.

In addition, as shown in the figure, on both sides of the forming part A, the bunch P has an angle βO′c that is approximately parallel to the upper surface of the rough arm portion 21 that is extended and formed in correspondence with the forming surface 28 of the die 25. A surface 29 is formed. Further, in the Y direction centered on the receiving hole 26 of the molding part 28 formed in the X direction of the die 25, a wall surface that restricts molding of the width side surface of the rough arm part 21 to a predetermined width dimension S is continuous with the molding surface 28. It is installed vertically. Therefore, the roughly cylindrical rough yoke portion 17 is crushed by the pressing operation of the bunch P, and the rough arm portion 21 is formed to extend at an angle α in the left and right X directions, and the four portions 27 are thickened and A roughly circular convex rough base 20 is molded, and the Dowa base 20 has an extra thickness 2 shown by hatching.
0a is attached. Also, at the same time, a part of it is in the receiving hole 2.
6 is extruded to a length Δp, and the coarse shaft portion 16 has a length 1.
It is formed in the child shaft portion 22 of No. 2. Furthermore, the bunch P is operated by pressing the width side of the rough arm portion 21 along the wall surface that regulates forming, and the extension angle β of the upper surface 24 of the rough arm portion 21 is equal to the radius R of the forming portion Δ. Since it is determined by the material, the defining surface 2 formed by the angle βO of the bunch P
There is almost no contact with 9 and there is no occurrence of cracks or the like. Further, since the receiving hole 26 through which the coarse shaft portion 16 is inserted is inserted in stages in seven directions at the center of the die 25, the in-phase shaft portion 16 has a load relief from the bunch P. As a result of the above effects, the maximum machining surface pressure near the center of the die 25 by the punch P can be lowered to 50% or less of the crushing load of the mold, and the life of the mold can be significantly increased. Since elastic deformation is significantly reduced, there is no occurrence of cracks, etc. The preformed member 19 formed in this manner is formed into a yoke member 30 in an arm bending process.

In this arm bending process, the yoke base 5 and the reinforcing thick part 6 are formed by crushing the rough base 20, and the rough arm 21 is also bent and roughly ironed. Generally, a thick rough base 20 having an extra wall portion 20a is formed into a bunch P-
When forming the yoke base 5 and the reinforcing thick part 6 by crushing, as shown in FIG. The elongation rate becomes greater than the elongation rate on the punch P' side, and as a result, the left and right rough arm portions 21 are bent as shown. Therefore, in this arm bending process, the rough arm part 21 is bent by utilizing the bending phenomenon caused by this compression process. A movable outer bunch 32 is provided opposite to the counter punch 31 , and a sleeve 33 is slidably fitted into the outer bunch 32 along the axis of the counter punch 31 . Child shaft part 22
A receiving hole 34 for inserting the sleeve 33 is provided therethrough, and a mold hole 35 for molding the yoke base 15 and the reinforcing thick portion 6 is formed on the opposing surface of the sleeve 33. Note that 36 is a knockout. In a device provided in this way,
As shown in FIG. 13, the child shaft portion 22 of the preformed member 19 is inserted into the receiving hole 34 of the sleeve 33 and set as shown. Thereafter, the sleeve 33 and the outer bunch 32 are simultaneously advanced to crush and form the rough parking portion 20. By this crushing, the excess wall portion 20a on the lower side of the rough arm portion 21 of the rough base portion 20 is crushed, and the elongation rate on the lower surface 23 side of the rough arm portion 21 is higher than that on the upper surface 24 side, and the left and right rough arm portions 21 can be compressed and bent at the same time as shown in the figure, and the thickness H of the lower part of the rough arm part 21 can be formed to be large. Then, only the outer punch 32 moves forward, and the rough arm portion 21 is ironed by the counter punch 31, and the outer surface (lower surface 23) is formed into a convex curved surface 8 with a length H2 and a width S, thereby forming the arm 7. The shape of the tip end of this arm 7 is such that a part of the diameter of the material does not touch the mold in each process, as shown by thick lines in Figure 8 (a), (b), and (c).
Furthermore, since the tip end shape can be formed into an arcuate shape without being significantly deformed, the conventional process of trimming the arm tip of the yoke formed by cold forging can be omitted.

When the yoke base 5 and the arm 7 are molded in this way, the outer bunch 32 and the sleeve 33 are retracted, and the knockout 36 is activated so that the yoke member 3
0 is paid out from the sleeve 33. The thus formed yoke member 3o is machined to form the bearing hole 9 and the serrations 3 (which may be plastically worked) in a machining process, thereby forming the yoke 1 with a shaft portion.

Normally, when assembling the cross shaft 11 to the yoke, a relief part 37 is cut at the tip of the arm 7 as shown in Figures 16 and 17 to avoid interference. In this example, in the second step, J3 and bunch P) current control surface 2
A convex portion (not shown) that forms the relief portion 37 at a predetermined position of 9.
By providing this, the relief portion 37 can be formed during molding of the rough arm portion 21, and the relief portion 37 remains in almost the same shape even after the arm bending and forming process, so the cutting process of the relief portion 37 is not necessary. It is important to omit .

The arm bending process is separated into an arm bending process in which the rough base 21 and the rough arm part 22 are crushed and bent, and an arm part forming process in which the rough arm part is bent and ironed, as shown in FIG. 3(B). In this case, punch
The structure of the die can be simplified and a general press can be used.

(Effects of the Invention) As described above, if the method for manufacturing a yoke with a shaft portion of the present invention is applied, the maximum machining surface pressure in the arm extension process and the arm bending process will be 50% or less of the crushing load of the mold. As a result, the elastic deformation of the mold is significantly reduced, and there is no occurrence of flaking due to the mating part of the punch and die, and the machining surface pressure is less than 50% of the crushing load of the mold, so the mold will not collapse due to fatigue. is significantly reduced, and the mold life can be greatly improved. In addition, in the arm bending process, crushing and bending are performed at the same time, and in particular, since an extra wall is provided on the base side of the rough arm, the thickness of the base of the arm can be increased. This makes it possible to increase the section modulus of the base where maximum stress occurs, and since the base of the arm is bent by compression, compressive stress can remain on the surface of the base of the arm. Additionally, static strength can be achieved by utilizing continuous fiber flow and work hardening due to cold forging.

A yoke with a shaft portion having excellent fatigue strength can be obtained.

In addition, since the torque transmitting shaft portion 2 is integrally formed, there is no risk of breakage at the joint unlike in yokes joined by welding, etc., so reliability can be improved and machining can be improved. Since the cost can be reduced, the manufacturing method of a yoke for a universal joint having a shaft portion is extremely useful in industry.

[Brief explanation of drawings]

The drawings show an example of the present invention, and FIG. 1 (A) is a partially cutaway front view of a yoke for a universal joint having a completed shaft portion according to the present invention, and FIG. ) is a side view, FIG. 2 is a partially cutaway view showing an example of the use of the yoke of the present invention, FIGS. 3 (A) and (B) are cold forging process diagrams,
Figure 4 is a front view of the material, Figure 5 is a front view of the roughly formed part,
Figure 6 is a front view of the preformed member, Figure 7 is a front view of the yoke member, Figures 8 (a) and (b) are plan views of the roughly formed member and the preformed member, and Figure 8 (c) is A side view of the yoke member, FIGS. 9 and 10 are explanatory diagrams of the properties of the crushing of the rough yoke part in the arm extension process, and FIGS.
The figure is an explanatory diagram of the properties of the crushing and bending of the rough part d3 and the rough arm part in the arm extension process.
The figure is an explanatory diagram of the assembly number of the cross shaft, and FIG. 17 is a perspective view of the rough arm part with a relief part formed therein. 1...Yoke for universal joint with right shaft

Claims (2)

[Claims] (1) A method for manufacturing a yoke member, which integrally includes a yoke base perpendicular to the axis of a coaxial portion at one end of a shaft portion, and a pair of arms extending from the yoke base in a direction opposite to the shaft portion. (a) a material taking step of taking a material having a volume substantially equal to the overall volume of the yoke member, and (b) a rough forming member consisting of a rough shaft portion and a rough yoke portion by cold forming the material. (c) an arm extension step of forming a preformed member by crushing and molding the rough yoke portion of the roughly formed member and extending the rough base portion and the rough arm portions on the left and right sides; (d) includes the step of crushing and forming the rough base of the preformed member, bending the rough arm portion, and ironing the rough arm portion to a predetermined width and thickness; bending and ironing the preformed member to form the rough base; , an arm bending and forming step in which the rough arm portion is made up of a yoke base and an arm portion; in particular, in the arm extension step, the step includes a receiving hole into which the rough shaft portion of the rough forming member is inserted; The axis of the hole is set in the Z direction, the forming surface is inclined upward at a predetermined angle in the X direction of the axis, and a recess is formed at the end of the receiving hole to form a rough base that will become the yoke base. The cross section in the X direction is approximately wedge-shaped with respect to the axis of the die and the receiving hole, and has a molded part of a predetermined diameter at the tip, and continues to this molded part in the X direction in correspondence with the molded surface of the die. It has a shaft portion configured to crush and press the rough yoke portion of the rough molded member with a punch having a forming surface that is upwardly inclined at a predetermined angle to extend and mold the rough arm portion in the X direction. How to manufacture a yoke for universal joints. (2) A method for manufacturing a yoke member, which integrally includes a yoke base perpendicular to the axis of the coaxial portion at one end of the shaft portion, and a pair of arms extending from the yoke base in a direction opposite to the shaft portion. (a) a material taking step of taking a material having a volume substantially equal to the overall volume of the yoke member, and (b) a rough forming member consisting of a rough shaft portion and a rough yoke portion by cold forming the material. (c) a preforming step in which the rough yoke portion of the rough formed member is crushed and molded to form a rough base portion having an excess thickness portion, and a rough arm portion is formed to extend on the left and right sides to form a preformed member; (d) an arm bending step of forming a yoke base by crushing the rough base portion having the excess thickness of the rough formed member, and bending the rough arm portion; (e) the rough arm portion The arm part bending process consists of bending and ironing the preformed member to form it into a predetermined width and thickness. In particular, in the arm bending process, a receiving hole into which the preshaft part of the preformed member is inserted is formed using a die. penetrated into the
A mold hole for molding the yoke base is formed at the end of the receiving hole, and a punch is arranged on the axis of the mold hole to crush and press the rough base to mold the yoke base. A method for manufacturing a yoke for a universal joint having a shaft portion, characterized in that the rough arm portions are bent and formed into a substantially opposite shape by crushing the excess thickness by crushing and pressing.