JPH0378491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a universal joint, and more particularly to a universal joint using a yoke formed of a base portion and yoke portions rising from both sides of the base portion.

[Conventional technology]

Conventionally, this type of universal joint has been used as a part of a steering device of an automobile, as shown in FIGS. 9 and 10, for example. This example shows a case where the steering shaft 1 and the steering gear device 2 are connected by a lower joint 3, and the yokes 5 and 6 are attached to the upper and lower ends of the lower shaft 4, respectively, and the corresponding steering shaft 1 and yokes 8, 9 attached to the ends of the gear shaft 7, respectively, are swingably connected by trunnions 10a, 10b. Furthermore, the lower joint 3 is equipped with a vibration-proofing structure to prevent road vibrations from the tires and vibrations from the engine, suspension, etc. from being transmitted into the vehicle interior through the steering shaft 1. The vibration isolation structure is as shown in Figure 10.
A disk-shaped vibration isolating rubber 11 is fixed to the tip of the lower shaft 4 with bolts 12 and nuts 13, and a yoke 5 is connected to this vibration isolating rubber 11. For this reason, road vibrations from the tires are transmitted to the lower joint 3.
When the vibration is transmitted to the vibration isolating rubber 1
1, most of the noise is absorbed, and transmission of vibrations and abnormal noises into the vehicle interior through the steering shaft 1 is prevented.

By the way, in this type of lower joint 3, as the yoke 5 fixed to the vibration isolating rubber 11, those shown in FIGS. 10 to 12 are conventionally known. This is a metal plate consisting of a diamond shape,
It is bent at both sides in the longitudinal direction to form a substantially U-shaped cross section, with holes 14a for attaching vibration-proof rubber,
It consists of a base part 15 which is opened at the opposite end position of the trunnion 14b, and yoke parts 17a and 17b which are provided with bearing mounting holes 16a and 16b for supporting the trunnion 10a.
(Refer to Publication No. 172930). The yoke 5 formed in this way is attached to the lower shaft 4 as shown in FIG.
It is attached to the tip of the vibration isolating rubber 11,
In this case, the anti-vibration rubber 11 is attached to a mounting flange 18a extending in the left-right direction at the tip of the lower shaft 4,
18b with bolts 12 and nuts 13, and the yoke 5 is placed on the vibration isolating rubber 11 between the left and right vibration isolating rubber fixing bolts 12, 12 protruding from the upper surface of the vibration isolating rubber 11, The above bolt 12,
It was fixed to the anti-vibration rubber 11 with a bolt 19 at a position on a line substantially perpendicular to the straight line connecting the parts 12. Further, the yoke 5 fixed to the tip of the lower shaft 4 in this manner is connected to the steering shaft 1 via the trunnion 10a supported by the bearing device holes 16a, 16b of the yoke parts 17a, 17b.
A side yoke 8 is swingably connected.

[Problem to be solved by the invention]

However, in the conventional universal joint described above, the yoke 5 has a base portion 15 formed by bending both sides of a substantially diamond-shaped metal plate, and yoke portions 17a rising from both sides of the base portion 15.
17b, the anti-vibration rubber 11
When the yoke 5 is attached to the base portion 15, the top portions 15a and 15b of the diamond-shaped plates forming the base portion 15 are attached to the vibration isolating rubber 1.
In some cases, the yoke 1 protrudes outward, and the radius of rotation at the joint becomes larger due to the protrusion.In addition, in the conventional yoke 5 formed from a diamond-shaped plate material, the base part Since gentle slopes 20a and 20b are formed on both sides of the yoke parts 17a and 17b rising from the yoke parts 15,
The width dimensions of the yoke portions 17a and 17b become large, and the swing angle is restricted in relation to the mating yoke 8 connected to the yoke 5. As a result, there were problems in that the available space around the lower joint was reduced, such as the free seat available when laying out the steering system.

Furthermore, in the conventional universal joint, when the vibration isolating rubber 11 is fastened to the lower shaft 4, the bolt 12 must be located outside the yoke parts 17a and 17b, so the shape of the vibration isolating rubber 11 becomes larger. There was also the problem that the lower joint 3 itself became larger and heavier.

[Means to solve the problem]

In order to solve the above-mentioned conventional problems, the present invention provides a universal joint that can make effective use of the space around the lower joint and reduce the size and weight of the lower joint by downsizing the yoke attachment part. The means for this purpose is a flexible shaft consisting of a shaft, a vibration isolator fixed to the tip of the shaft, and a yoke placed on the upper surface of the vibration isolator and fixed to the vibration isolator. The joint has a mounting flange formed at the tip of the shaft for fixing a vibration isolator, and a fastener for fixing the shaft and yoke on the disc-shaped vibration isolator. A pair of holes are opened at orthogonal positions, and the yoke is
Each of the yoke parts of a plate material is provided with a circular base part having the same shape as the vibration isolating material, and yoke parts of approximately equal width that protrude from both sides of the base part with rounded corners, each of which is set as the base part. By folding the folded line as a reference, a base part with both sides removed and a yoke part of approximately equal width rising from this base part with a radius are formed. A hole is opened through which a fastener is inserted to fix the vibration isolator to the vibration isolating material.
The rising part of the yoke part including the center part of the above-mentioned folding line has a reinforcing rib and a recess formed by inwardly recessing the plate material of this part, and the shaft is inserted into the recess from the mounting flange side of the shaft. The tip of the fastener inserted into the hole in the vibration isolator was accommodated, and the base of the yoke and the vibration isolator were fixed by the fastener on the circumference of the vibration isolator that was offset by approximately 90 degrees from the fastener. It is made by means of a universal joint.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings.

1 to 4 show an embodiment of a yoke applied to the universal joint of the present invention, and this yoke 21 is made by pressing a metal plate material having a predetermined shape, as in the conventional example. As shown in FIG. The shape includes yoke portions 24a and 24b having approximately the same width W and protruding from each other.
Folding lines 26a and 26b intersecting the long axis 25 of the plate material 22 are set near the yoke parts 24a and 24b in the base portion 23 of the plate material 22, and for example, a lower mold as shown in FIG. It is molded by press working using a yoke molding device 27 consisting of a mold 27a and an upper mold 27b. In this press working, the yoke portions 24a and 24b on both sides are raised with reference to the folding lines 26a and 26b,
A circular base portion 28 with both sides cut out, and yoke portions 30a and 30b of approximately equal width rising from the base portion 28 with a radius 29 are formed.
Note that the attached radius 29 includes a convex radius 29a attached to the rising portion of the base portion 28 and a concave radius 29b following this convex radius 29a, as shown in FIGS. 1 and 4 due to molding. This concave radius 29b connects the yoke portions 30a, 3
It connects smoothly to the top of 0b.

In addition, in this embodiment, the yoke forming device 2
Protrusions 31a, 31b and recesses 32a, 32b are provided at the corners of the lower die 27a and on both sides of the tip of the corresponding upper die 27b, respectively.
Embossing is performed from the outside on the peripheral portions of the folding lines 26a and 26b, that is, on the cutout side of the base portion 28 including the center portions of the folding lines 26a and 26b, and on the rising portions of the yoke portions 30a and 30b. Therefore, by this embossing, the inside of the yoke 21 has a base part 28 and yoke parts 30a, 30.
Inward reinforcing ribs 33a, 33b spanning b.
is formed. And, these reinforcing ribs 33a, 3
3b reliably prevents spring back of the yoke parts 30a and 30b, and also
The trunnion support strength of 0a and 30b increases.
In addition, the reinforcing rib 33 is also
On the outer surface of the yoke 21 corresponding to a and 33b,
Recesses 34a, 34b having sizes corresponding to the reinforcing ribs 33a, 33b are formed. This recess 34
a, 34b, as shown in FIGS. 1 and 7,
Anti-vibration rubber mounting surface 28a which is the lower surface of the base part 28
The recesses 34a, 34b are formed to be located inward from the outer surfaces 52a, 52b of the trunnion attachment portions of the yoke portions 30a, 30b.
This will allow you to store the yoke mounting bolts, which will be described later.

Incidentally, bolt insertion holes 36a and 36b for attaching anti-vibration rubber 35, which will be described later, are provided in the flat part of the base part 28 at positions orthogonal to the yoke parts 30a and 30b, and the left and right yoke parts 30a ，
Bearing mounting holes 37a and 37b for supporting the trunnion are provided in the upper part of 30b, respectively.

Next, a means for assembling the lower joint 3 using the yoke 21 having the above-mentioned shape is shown in FIGS. 5 to 7.
This will be explained based on the diagram. In the lower joint 3,
A vibration isolating structure is provided using a disk-shaped vibration isolating rubber 35 as a vibration isolating material. having a disc shape,
The inside is reinforced with fibers, and there are four bolt insertion holes 3 on the same radius on the orthogonal line passing through the center of the circle.
8a, 38b, 38c, and 38d are open. Among these, a pair of bolt insertion holes 38a and 38c located at opposing positions are for inserting bolts 40a and 40c as fasteners for fixing the lower shaft 39, and inside the holes are bushes 41a and 40c that protrude downward. 41c is installed. Also,
A pair of bolt insertion holes 38b, 38 perpendicular to this
d is for inserting bolts 40b and 40d as fasteners for fixing the yoke 21, and inside thereof there are bushes 41b and 41 that protrude upward.
d is attached. In addition, each of the above-mentioned bushes 41a,
41c, 41b, 41d have plastic collars 42a, 42c, 42b, 42 on their protruding parts.
stopper plates 43a, 43b are interposed on the lower and upper surfaces of the vibration isolating rubber 35, respectively, so as to sandwich the plastic collars 42a, 42c, 42b, 42d. This stopper plate 43a,
Reference numeral 43b is a metal disc member commonly used by the bolt insertion hole 38a (3) of the vibration isolating rubber 35.
8b), 38c (38d), and bolt holes 44a, 44b are provided on both sides corresponding to 38c (38d).
Plastic collar 42a is placed 90 degrees off.
(42b), 42c (42d) are fitted into cutout recesses 45a and 45b. These stopper plates 43a, 43b prevent the vibration isolating rubber 35 from twisting when the joint portion rotates, and function as stoppers by touching the notched edges of the notched recesses 45a, 45b to the plastic collar. . In addition, the above notch edge is made of anti-vibration rubber 3.
It is formed so that it is curved on five sides,
This prevents the vibration isolating rubber 35 from digging in. Further, a mounting flange 46 projecting to the left and right is integrally provided at the tip of the lower shaft 39, and a serration 47 for attaching a yoke on the gear shaft side is provided at the rear end.

In order to assemble the yoke 21 to the upper part of the lower shaft 39 via the anti-vibration rubber 35, first the mounting flange 4 of the lower shaft 39 is assembled.
Bolt holes 48a, 48b opened at the left and right ends of 6
Anti-vibration rubber fixing bolts 40a, 40c are inserted into the bolts 40a, 40c through plastic collars 42a, 42c, and the bolts 40a, 40c are inserted into the bolt insertion holes 38a, 38c of the anti-vibration rubber 35 and placed on the upper surface of the anti-vibration rubber 35. Bolt hole 4 of stopper plate 43b
4a, 44c, and the stopper plate 4
The anti-vibration rubber 35 is attached to the mounting flange 46 of the lower shaft 39 by screwing nuts 49a, 49c onto the tips of the bolts 40a, 40c which protrude upwards.

Next, bolts 40a, 4 for fastening the vibration isolating rubber.
The recess 34a of the yoke 21 is located at the tip protruding portion of the yoke 0c.
Place the yoke 21 so that the yoke 34b is positioned, and insert the bolt insertion hole 36 from the top surface of the base portion 28.
Bolts 40b, 40 for fastening the yoke to a, 36b
Insert d. And this bolt 40b, 40
A stopper plate 4 is arranged on the bolt insertion holes 38b and 38d of the anti-vibration rubber 35 and the lower surface of the anti-vibration rubber 35 via plastic collars 42b and 42d.
The yoke 21 is attached to the vibration isolating rubber 35 by passing through the bolt holes 44a, 44b of the bolt 3a and screwing the nuts 49b, 49d onto the tips protruding from the stopper plate 43a. In addition, as shown in FIG. 8, a pin 50 is used instead of the bolt fastening means.
The yoke 21 and the vibration isolating rubber 35 can also be attached to the lower shaft 39 by the fixing means provided by a, 50b, 50c, and 50d.

In the lower joint 3 in which the yoke 21 is assembled in this way, since the base portion 23 of the yoke 21 has a basic circular shape with approximately the same diameter as the shape of the vibration isolating rubber 35, the inside of the vibration isolating rubber 35 is The entire base portion 23 can be housed in the yoke 21, and the yoke 21 can be rotated within the rotation radius of the vibration isolating rubber 35. As a result, the yoke 21 can be made smaller and lighter.

Further, in this embodiment, reinforcing ribs 33a, 33 extend from the base portion 28 to the yoke portions 30a, 30b.
By forming the yoke portions 30a and 30b and increasing the rigidity of the yoke portions 30a and 30b, the yoke portions 30a and 30b are raised from the base portion 28 with approximately the same width. The width of the yoke portions 30a and 30b can be made narrower than that of the yoke portions 30a and 30b, and as shown in FIG. , the degree of freedom increases when laying out the steering device of an automobile.

In addition, in this embodiment, the tip protrusions of the bolts 40a and 40c for fastening the vibration isolating rubber 35 are connected to the yoke 21.
Since the bolts 40a and 40c can be stored in the recesses 34a and 34b of
That is, it can be provided within the circular base portion 23 that forms the base portion 28 of the yoke 21, and as a result, the shape of the vibration isolating rubber 35 itself can be reduced.

In addition, if the vibration isolation structure of the lower joint is provided on the gear shaft side, the above-mentioned yoke 2 can be used as a universal joint between the gear shaft and the lower shaft.
1 can be applied, and can also be widely used in universal joints other than those described in the above embodiments.

〔Effect of the invention〕

As explained above, since the universal joint according to the present invention is configured as described above, the rotation radius of the yoke itself can be reduced, and the swing angle can be increased in relation to the mating yoke. . In addition, the reinforcing ribs protruding from the inside of the yoke ensure sufficient strength as a yoke, making it possible to form a yoke part that rises from the base part with approximately the same width, and the back side of this reinforcing rib Since a recess is formed in which a portion of the bolt for fastening the anti-vibration rubber can be accommodated, the fastening position of the bolt can be provided within the base portion of the circular yoke. Therefore, it is possible to reduce the size of the yoke attachment part by reducing the shape of the vibration-proof rubber itself, thereby making it possible to reduce the weight of the entire joint part and make effective use of the space around the joint part.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a yoke applied to the universal joint of the present invention, Fig. 2 is a plan view of the yoke, Fig. 3 is a sectional view showing an embodiment of a yoke forming device, and Fig. 4 is a side view of the yoke. Fig. 5 is an exploded perspective view of the members constituting the universal joint, Fig. 6 is an assembly diagram of the universal joint, Fig. 7 is a partial sectional view taken along the line - - in Fig. 6, and Fig. 8 shows the fastening means. A cross-sectional view similar to FIG. 7 in a different case,
FIG. 9 is a perspective view schematically showing the steering device;
Figure 10 is an assembly diagram showing an example of a conventional universal joint;
FIG. 11 is a plan view showing an example of a conventional yoke, and FIG. 12 is a side view of the yoke. 21...Yoke, 22...Metal plate material, 23...
...base part, 24a, 24b...yoke part,
26a, 26b... bending line, 28... base part,
28a...Vibration isolation material mounting surface, 29...R, 30
a, 30b... Yoke portion, 34a, 34b... Recess, 35... Vibration isolating rubber (vibration isolating material), 39... Shaft (lower shaft), 40a, 40b... Bolt (fastener), 52a, 52b ...The outer surface of the trunnion attachment part of the yoke.

Claims (1)

[Scope of Claims] 1. A universal joint consisting of a shaft, a vibration isolator fixed to the tip thereof, and a yoke placed on the upper surface of the vibration isolator and fixed to the vibration isolator, A mounting flange for fixing a vibration isolator is formed at the tip of the shaft, and a hole is formed in the disk-shaped vibration isolator through which a fastener is inserted to fix the shaft and yoke. A pair of yokes are provided at orthogonal positions, and each yoke has a circular base portion that has the same shape as the vibration isolating material, and yoke portions of approximately equal width that protrude from both sides of this base portion with rounded corners. By folding each yoke part of the plate material based on the folding line set at the base part, a base part with both sides removed and a yoke part of approximately equal width that is rounded and rises from this base part. The base part is formed with a hole through which a fastener for fixing the yoke to the vibration isolating material is inserted, while the rising part of the yoke part including the center part of the folded line is provided with a hole corresponding to the hole. It has a reinforcing rib and a recess formed by inwardly recessing the plate material of the part, and the tip of the fastener inserted into the hole in the vibration isolator from the shaft mounting flange side is stored in this recess. Also, a universal joint characterized in that the base portion of the yoke and the vibration isolator are fixed by a fastener on the circumference of the vibration isolator that is offset by approximately 90 degrees from the fastener.