JPH03140628A - Yoke for universal coupling and manufacture thereof - Google Patents

Abstract

PURPOSE:To reduce weight and cost by bending a plate into an almost V-shaped form, while molding a shaft joint base solidly to a folk part which formed a curved almost V-shaped projection whose internal surface is engaged with a resin ball after bending it into a crown form, and installing a through hole in the center. CONSTITUTION:A plate is bent into an almost V-shaped form so as to have a pair of fork parts 6, while a curved V-shaped projection 8, where each internal surface of these fork parts 6 is engaged with a groove of a resin ball, is formed and then a rib 7 is projected outward the longitudinal direction of an outer surface. In addition, a base part 9 connecting a shaft solidly with the fork parts 6 is bent into a crown form while a through hole 10 is installed in the central part. Accordingly, since the plate is subjected to die forming, it can be manufactured without giving any adverse effect to a manufacturing work environment with no heating process besides lighter in weight and inexpensive in cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a yoke of a universal joint used in a steering device of an automobile and a method of manufacturing the same.

[Prior Art] In general, a steering system for an automobile connects an intermediate shaft with a universal joint to the lower end of a steering shaft on which a steering wheel is mounted, and connects the lower end of the intermediate shaft with a steering gear box using a universal joint. When the steering shaft is rotated, the left and right steering wheels are rotated about the ground plane via the steering gear box.

A common universal joint in the above-mentioned steering device is a so-called Cardan-type press yoke joint, which has a pair of yokes facing each other and connects the yokes with a cross-shaped trunnion to allow bending, bending, and rotation. It is configured to be able to transmit torque. The trunnion and the yoke are connected, for example, by drilling a through hole at the end of the yoke, fitting a bearing cup into the through hole, and interposing a needle bearing in the annular shape in the bearing cup to connect the end of the trunnion. When the spider is inserted, a seal ring is fitted between the base of the spider and the bearing cup, and a lubricant such as grease is sealed inside to prevent water droplets from entering.

However, recently, a resin ball joint in which a resin ball is engaged with a yoke in place of the trunnion has been provided (see Japanese Patent Laid-Open No. 131032/1982). this is,
This is a so-called Angusson joint, in which a yoke sandwiches a resin ball in its diametrical direction.
As shown in the figure, the fork portion 5 is curved with a predetermined curvature.
0, a block 5I obtained by dividing the spherical part of a resin sphere into four parts, a pair of pyramid-shaped blocks 52 interposed opposite to each other at their centers, and the pyramid-shaped blocks 52 arranged outwardly from each other. It has a pushing spring 53, and the fork 15
V formed between block 5I divided into four by 0
It is a configuration that engages with '711154.

The blocks 51 and 52 are in contact with the block 52 at the tapered surfaces 55 and 56, and the block 52 is always pushed outward by the spring 53, so that a force that causes the block 5I to come into sliding contact with the fork portion 50 is always applied. . The yoke 57 in this example is made of aluminum made by aluminum casting or iron made by so-called hot forging.

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional Anderson type joint, the yoke is produced by aluminum die casting or hot forging, which results in considerable weight and requires a large amount of material, resulting in high cost. In addition, the manufacturing method requires a step of heating the material, which has an adverse effect on the working environment.

Therefore, in view of the above circumstances, this invention is lightweight and
This was done for the purpose of obtaining a yoke that can be manufactured at low cost and is functionally equivalent to or better than the above-mentioned conventional example.

[Means for Solving the Problems] In order to solve the above problems, the present invention has a pair of fork portions formed by bending a plate material into a substantially V-shape, and the inner surface of the fork portions is curved so as to engage with the groove of the resin ball. In addition to forming a V-shaped protrusion, the outer surface protrudes outward in the shape of an elongated helical plate, and the base part, which is integral with the fork part and connects the shaft, bends the plate material into a crown shape. a step of forming a blank by punching out a blank from a plate material, which forms a yoke of a universal joint having a through hole in the center thereof, and has a disk portion and tongue portions of a predetermined length that face each other in the diametrical direction; A first drawing step in which the tongue portion of the blank is formed into a substantially V-shaped cross section, a second drawing step in which the disk portion of the blank is formed into a crown shape, and an irregularly shaped transparent hole is formed in the center of the disk portion. The fork part is curved to form a longitudinal rib on its outer surface, and a V-shaped protrusion having a predetermined curvature on its inner surface. The method for manufacturing a yoke for a universal joint includes a forming process for forming a V-shaped protrusion.

[Function] According to the above structure of the present invention, the yoke is formed by bending the plate material, the base has a through hole for connecting the shaft, the fork part is curved with a predetermined curvature, and the outer surface is provided with ribs. and,
Since a V-shaped protrusion is formed on the inner surface, the resin ball is held in place with high rigidity, while the shaft is caulked and connected to the through hole to form a lightweight universal joint that does not impede torque transmission.

Furthermore, since no heating work is required in the process of manufacturing this yoke, adverse effects on the working environment are prevented.

[Embodiment] Next, an embodiment of the present invention will be described based on the drawings. 1st
The figure shows a state in which a pair of yokes 1.2 are connected as a universal joint with a resin ball 3 in between, and a shaft 4.5 is connected to each of the yokes 1.2. As shown in FIG. 2, the fork portion 6.6 of the yoke 1.2 has a substantially V-shaped cross section, and a rib 7.7 extending in the longitudinal direction is formed on its outer surface, and a V-shaped protrusion is formed on its inner surface. 8 is formed and is curved in an arc shape as a whole. Further, the base portion 9 integrally formed with the fork portion 6.6 has a so-called crown-shaped cross section.

To connect the yoke 1.2 and the shaft 4.5, an oval-shaped through hole 10 is bored in the center of the base 9, and an oval-shaped cross section that fits into the through hole 10 is connected, for example, to one end of the shaft 4. The base portion 9 is formed on the shaft 4 so that they fit together, and the base portion 9 is pressed against the shaft 4 to be caulked. That is, as shown in detail in FIG. 4, each yoke 1.2 has a pair of fork portions 6.6 formed by bending a plate material into a substantially V shape, and the inner surface of the fork portions 6.6 is a resin ball. Curved V that engages the groove of 3
a base 9 forming a letter-shaped protrusion 8.8, whose outer surface protrudes as a longitudinal outer helix 7, 7, and which connects the shafts 4, 5 integrally with the fork parts 6;
is formed by bending a plate material into a crown shape, and drilling an irregularly shaped through hole 10 in the center thereof.

As shown in Figures 2 and 3, the resin ball 3 is made by equally dividing the ball into four blocks! 1, square pyramidal blocks 12 and 12 are housed in their centers, and springs 13 are elastically mounted to push the blocks 12 and 12 outward from each other. Block 11.1
Block 12.2 has its slopes engaged with each other through dovetail grooves.
12 is moved outwards so that block 11.11 can move outward conically through its slope. 14 is a ring for connecting the blocks 11 through each other.

According to the above-mentioned universal joint, for example, when rotational torque is manually applied to the shaft 4, the force is transmitted to the yoke l, via the fork portion 6.6, the resin ball 3, and the fork portion 6.6 of the yoke 2. The signal is transmitted to the shaft 5. Since each fork portion 6.6 of the yoke 1.2 has the block 1.1 interposed therebetween, torque is transmitted while compressing the block 11. When wear occurs on the engagement surface between the fork portion 6.6 and the block 11, the block! 2゜12
are pushed outward from each other by the force of the spring 13, so the blocks 11 move outward via the slopes of each other,
Automatic adjustments are made to compensate for the amount of wear.

The yoke 1.2 is formed by the following manufacturing method. That is, as shown in FIG. 5(A), a suitable plate material is punched out using a press to integrally form a substantially circular disk portion 20 in the center and tongue portions 21, 21 projecting wing-like on the left and right sides of the disk portion 20. Then, as shown in FIG. 5(B), the tongue portions 21 and 21 of the blank 22 are formed into tongue portions 2! by the upper mold 23 and the lower mold 24. , 21 are press-molded so that they each have a basically V-shaped cross section (first drawing step). Upper mold 23
The mold surface 25 has an arcuate surface with a predetermined curvature, and the lower mold 24 has a V-shaped groove 26 formed therein. Through this first drawing step, as shown in FIG. 5(b), the flat disk portion 20
Fork forming portions 27 having a substantially V-shaped cross section are formed on both left and right sides of the fork forming portion 27 . Then, as shown in FIG. 5(C), the disk portion 20 is placed on a lower die 28 and press-molded using an upper die 29 so that the disk portion 20 has a so-called crown shape (second drawing step).

As shown in FIG. 5(D), the lower die 28 is of a so-called weight shape having concave portions 30, 30 which are curved in a substantially V shape with the short axis side of the substantially elliptical shape facing the axis center. A convex portion 31.31 having an external shape similar to that of the convex portion 31 is formed on the upper die 29. Through this second drawing process, the base forming part 32 is formed integrally with the fork forming part 27, as shown in FIG. 5(d). Next, as shown in FIG. 5(E), a so-called oval-shaped cutting die 33 is pressed into the center of the base forming part 32 with a press or the like to punch it out (piercing step). Through this piercing process, as shown in FIG. 5(e), the base forming part 32
A through hole 34 (corresponding to the reference numeral IO in FIG. 4) for connecting the shaft is bored in the shaft. Then, as shown in FIG. 5(F), facing molds 35.35 and 36.36 are placed on the inside and outside of the fork forming portion 27.27, respectively, and these facing molds 35.36 are placed in the center, respectively. The fork forming portions 27 and 27 are pressed against each other to give a predetermined curvature (forming step). The opposed mold 35 has a wave-shaped mold surface 37 on the outer surface of the tongue portion 21, and the opposed mold 36 has a V-shaped protrusion 38 curved at a predetermined curvature on the inner surface of the fork forming portion 27 (reference numeral 8 in FIG. 2). ), it has a truncated conical shape. Through this forming process, as shown in FIG. 5(f), the fork forming portion 27 is curved with a predetermined curvature, and has a V-shaped protrusion 3B on its inner surface and a longitudinal direction on its outer surface. The fork is substantially completed with ribs 39, 39 (corresponding to the ribs 8, 8 in FIG. 1) projecting outward.

Finally, as shown in FIG. 5(G), a rotatable roller 40.
40, and the facing mold 35.35 is applied facing the outside,
Projection 3 formed on the inner surface of the fork forming portion 27.27
8.38 are formed by cutting or plastic processing using rollers by rotating opposing rollers 40 and 40 (forming step). The roller 40 has a truncated conical shape similar to the opposed type 36 described above. In addition, this forming process is carried out after the completion of the above forming process by using the opposing mold 36.
6 or the opposed type 36.36 to the roller 4.
All you have to do is replace it with 0.40 and rotate it.

[Effects of the Invention] According to the invention described above, since the yoke in the so-called Anderson type joint is formed by molding a plate material, it is possible to obtain a lightweight and inexpensive universal joint, and
Since no heating process is required, there are no adverse effects on the manufacturing work environment.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view showing a universal joint using a yoke according to the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. Figure 4 is a front view (Δ) showing the yoke according to the present invention, a process outline diagram of the manufacturing method,
6 to 8 are a perspective view, a partial perspective view, and a sectional view taken along the line XX in FIG. 6, showing a conventional example. 1.2... Yoke, 3... Resin ball, 6... Fork part, 7... Rib, 8... Projection, 9... Base,
DESCRIPTION OF SYMBOLS 10... Through hole, 20... Disk part, 21... Tongue piece part, 22... Blank, 27... Fork forming part, 3
2...Base forming part Fig. 4 (B) (C) 203- Fig. 5

Claims (2)

[Claims] (1) A pair of fork parts bend the plate material into a substantially V-shape, and the inner surface of the fork part forms a curved V-shaped protrusion that engages with the groove of the resin ball, and the outer surface has a longitudinal direction. The base part which protrudes outward in a rib shape and is integral with the fork part and connects the shaft is formed by bending a plate material into a crown shape, and has a through hole bored in the center part. universal joint yoke. (2) A blank forming process in which a blank is punched out of a plate material, having a disk portion and a tongue portion of a predetermined length that faces each other in the diametrical direction, and the tongue portion of the blank is formed to have a substantially V-shaped cross section. A first drawing step, a second drawing step of forming the disk portion of the blank into a crown shape, a piercing step of drilling a through hole in the center of the disk portion, and a step of curving the fork portion and extending the outer surface thereof. It is characterized by comprising a forming process in which ribs in the transverse direction are formed and a V-shaped protrusion having a predetermined curvature on the inner surface thereof, and a finishing process in which the V-shaped protrusion is made smooth. Method of manufacturing a yoke for a universal joint.