JPH0562741U - Constant velocity universal joint for steering - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a constant velocity universal joint for steering, which is capable of smooth power transmission without joint play. This steering constant velocity universal joint has an inner ring 1 in which a predetermined number of guide grooves 1a are axially formed on a spherical outer peripheral surface, and the same number of guide grooves 1a of the inner ring 1 are formed on a spherical inner peripheral surface. ,
Similarly, an outer ring 2 formed with a guide groove 2a extending in the axial direction, a plurality of balls 3 for transmitting torque by interposing between the guide grooves 1a, 2a of the inner and outer rings 1, 2 and an outer periphery of the inner ring 1. And a gauge 4 for holding the ball 3 between the surface and the inner peripheral surface of the outer ring 2, at least the outer ring 1 of the above-mentioned constituent members is molded from a fiber reinforced composite material, and the elasticity of this fiber reinforced composite material is utilized. The ball 3 is provided with a tightening margin so that the clearance between the inner and outer rings 1 and 2 becomes negative.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a constant velocity universal joint used for connecting a steering shaft to a steering gear in a steering device for a vehicle.

[0002]

[Prior Art]

 Generally, a vehicle is equipped with a steering device for controlling the traveling direction. This steering system consists of a steering wheel provided inside the driver's cab, a steering shaft connected to it, a steering gear, and a link mechanism leading to the front wheels. The direction of travel of the vehicle is controlled by turning the front wheels to the right or left via the.

Conventionally, in the above steering device, a cross joint that transmits rotational torque via a cross-shaped spider has been widely used as a joint that connects a steering shaft to a steering gear. This is because the cross joint does not have any joint play, and therefore power can be transmitted smoothly.

[0004]

[Problems to be solved by the device]

 However, in the above-described steering device in which the steering shaft is connected to the steering gear via the cross joint, the operating angle of the steering shaft with respect to the steering gear cannot be made very large because the operating angle of the cross joint is small. Therefore, the steering shaft is divided into a main shaft, one end of which is connected to the steering wheel, and an intermediate shaft, one end of which is connected to the steering gear through the cross joint, and these are separated from the cross joint different from the above cross joint. By connecting via a joint, the steering shaft is configured to have a large operating angle with respect to the steering gear.

However, in such a structure, the shape of the steering shaft is complicated, and since two joints are required, the number of parts is increased and the weight is increased.

[0006] Therefore, there is a means of using a constant velocity universal joint that transmits rotational torque via a plurality of balls, instead of the cross joint, instead of the joint connecting the steering shaft to the steering gear. That is, when a constant velocity universal joint is used to connect the steering shaft and the steering gear, the operating angle of the steering shaft with respect to the steering gear can be made large because the operating angle of the constant velocity universal joint is large. There is no need to divide the steering shaft into the main shaft and the intermediate shaft and connect them via a joint as in the above, and the shape of the steering shaft can be simplified and the weight can be reduced.

However, it is important for a joint used for a steering device of an automobile to have no joint play so that smooth power transmission can be performed, but there is no constant velocity universal joint satisfying such performance. Is the actual situation. That is, in the conventional constant velocity universal joint, the components such as the inner ring, the outer ring, the ball, and the gauge are made of a metal material, and a constant velocity universal joint in which the components are made of a metal material is Since the ball cannot be tightened, the clearance between the inner and outer rings and the ball causes joint play, which makes smooth power transmission impossible.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a constant velocity universal joint for steering that enables smooth power transmission. The challenge is to eliminate the joint play by making the gap between the inner and outer rings and the ball negative.

[0009]

[Means for Solving the Problems]

 The present invention has solved the problem by using a fiber-reinforced composite material as a material of at least the outer ring among the main constituent members.

That is, the constant velocity universal joint for steering according to the present invention has the same number of inner races formed on the spherical outer peripheral surface as the predetermined number of internal grooves in the axial direction, and the same number of guide grooves of the inner race formed on the spherical inner peripheral surface. The outer ring, which is also formed with a guide groove that also extends in the axial direction, a plurality of balls that transmit torque by interposing between the guide grooves of the inner and outer rings, the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. And a gauge that holds the ball between the ball and the ball, and at least the outer ring of the above-mentioned components is molded from a fiber-reinforced composite material, and the elasticity of this fiber-reinforced composite material is used to give a tightening margin to the ball. It is characterized by having done.

[0011]

[Action]

 According to the present invention, at least the outer ring is formed of a fiber-reinforced composite material, and the elasticity of the fiber-reinforced composite material is used to provide a tightening allowance to the ball, so that the gap between the inner / outer ring and the ball is negative. Therefore, there is no joint play.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of a constant velocity universal joint for steering according to the present invention. This constant velocity universal joint for steering is composed of an inner ring 1, an outer ring 2, a ball 3 and a gauge 4.

The inner ring 1 is spline-coupled to the end of the steering shaft 5, and a predetermined number of, for example, six guide grooves 1a are formed on the spherical outer peripheral surface in the axial direction at equal circumferential positions.

The outer ring 2 is formed of a fiber-reinforced composite member (for example, fiber-reinforced plastic) reinforced with carbon fiber or the like, and is spline-bonded to a steering gear (not shown). On the spherical inner peripheral surface of the outer ring 2, as many guide grooves 2a as the guide grooves 1a of the inner ring 1 and similarly extending in the axial direction are formed in a circumferentially equidistant arrangement.

The guide groove 1a of the inner ring 1 and the guide groove 2a of the outer ring 2 form a pair, and one ball 3 is arranged in each pair of the guide grooves 1a 1 and 2a.

The ball 3 is interposed between the guide groove 1 a of the inner ring 1 and the guide groove 2 a of the outer ring 2 to transmit torque therebetween, and is held at a predetermined position by the gauge 4. The ball 3 is assembled between the guide grooves 1a and 2a of the inner and outer rings 1 and 2 by utilizing the elasticity of the outer ring 2 which is molded from the fiber reinforced composite material. The tightening allowance is added so that becomes negative.

The gauge 4 has a spherical inner peripheral surface in contact with the outer peripheral surface of the inner ring 1 and a spherical outer peripheral surface in contact with the inner peripheral surface of the outer ring 2, and has a pocket 6 for holding the ball 4. It is formed in the radial direction with equal circumferential arrangement.

Reference numeral 7 in the drawing denotes a flexible boot mounted between the opening of the outer ring 2 and the steering shaft 5, and prevents foreign matter such as dust from entering the inside.

As described above, the constant velocity universal joint for steering according to the present invention uses the elasticity of the outer ring 2 formed from the fiber reinforced composite member to mount the ball 3 between the inner and outer rings 1 and 2. Since the clearance between the inner and outer races 1 and 2 and the ball 3 becomes negative by providing the tightening margin to the ball 3, joint play is eliminated and power transmission is smoothly performed.

FIGS. 3 and 4 show another embodiment of the constant velocity universal joint for steering according to the present invention, in which metal (for example, quenched steel) or oil-impregnated sintered material is provided in the guide groove 2a of the outer ring 2. Alternatively, by embedding a liner 8 formed of a wear resistant material such as ceramics, the outer ring 2 has a function of resisting wear due to friction with the balls 3. The embedding of the liner 8 is performed by molding with the outer ring 2 or a strong adhesive, and after embedding, precision is obtained by machining if necessary. Further, since the liner 8 is partially embedded in the guide groove 2a of the outer ring 1, the elasticity of the outer ring 1 can be utilized in the same manner as in the embodiment of FIGS. It is possible to assemble the outer rings 1 and 2 in a state in which the interference is provided between the guide grooves 1a and 2a. Further, the liner 8 is embedded in the guide groove 2a of the outer ring 2 in a divided manner, but it can be embedded so as to be integrally connected as shown in FIG.

In the above embodiment, the case where the outer ring 2 is formed of the fiber reinforced composite material has been described, but the present invention is not limited to this. For example, the inner ring 1 can also be molded from a fiber-reinforced composite material. In this case, since the elasticity of the inner ring 1 can also be used, the elasticity at the time of assembling is further increased to facilitate the assembling, and the ball 3 can be provided with a larger interference. Further, when the inner ring 1 is formed from the fiber-reinforced composite material as described above, if the guide groove 1a of the inner ring 1 is filled with the liner formed from the wear resistant material, the inner ring 1 is also subject to friction with the balls 3. It can be given the function of withstanding wear. Furthermore, if the gauge 4 is also formed from a fiber-reinforced composite material, the sliding resistance between the inner and outer races 1 and 2 is reduced, and smoother power transmission is possible.

[0023]

[Effect of the device]

 As described above, according to the present invention, at least the outer ring of the constituent members is molded from the fiber-reinforced composite material, and the elasticity of this fiber-reinforced composite material is used to form the ball between the inner and outer rings with a gap between the inner and outer rings. Since it is assembled with the tightening margin added so as to be negative, there is no joint play and smooth power transmission is possible, and the weight is significantly reduced compared to the case where all conventional components are made of metal material. To do. Therefore, in a steering device for an automobile, it is possible to simplify the shape of the steering shaft and reduce the weight.

Further, since the liner made of wear-resistant material is embedded in the guide grooves of the inner and outer rings made of the fiber-reinforced composite material, the inner and outer rings made of the fiber-reinforced composite material form a ball. It is possible to prevent abrasion due to friction.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line BB (in FIG. 2) showing an embodiment of a constant velocity universal joint for steering according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view taken along line D-D (in FIG. 4) showing another embodiment of the constant velocity universal joint for steering according to the present invention.

FIG. 4 is a sectional view taken along the line CC in FIG.

FIG. 5 is a partial cross-sectional view showing a modified example of the liner.

[Explanation of symbols]

 1 Inner ring 1a Guide groove 2 Outer ring 2a Guide groove 3 Ball 4 Gauge 5 Steering shaft 6 Pocket 7 Boot 8 Liner

Claims (2)

[Scope of utility model registration request] 1. An inner ring for connecting a steering shaft of an automobile to a steering gear, the inner ring having a predetermined number of guide grooves axially formed on a spherical outer peripheral surface, and the inner ring on a spherical inner peripheral surface. The outer ring is formed with the same number of guide grooves as that of the guide grooves extending in the axial direction, a plurality of balls for transmitting torque by interposing the guide grooves of the inner and outer rings, and the outer peripheral surface of the inner ring and the outer ring. And a gauge that holds the ball between the inner peripheral surface of the ball, and at least the outer ring of the constituent members is molded from the fiber-reinforced composite material, and the elasticity of the fiber-reinforced composite material is used to tighten the ball. A constant velocity universal joint for steering characterized by being added. 2. The constant velocity universal joint for steering according to claim 1, wherein a liner made of a wear resistant material is embedded in the guide groove of the outer ring or the inner and outer rings.