JP4096393B2 - Steering column bearing and bearing device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steering column bearing for supporting a steering column shaft of an automobile and a bearing device using the same.
[0002]
[Problems to be solved by the invention]
As a steering column bearing for supporting a steering column shaft of an automobile, a rolling bearing made of steel balls or a sliding bearing made of synthetic resin is used. Generally, for bearings that support the steering column shaft of an automobile, the rotational conditions such as load and speed are not so severe, but vibration absorption and friction torque that absorbs the vibration acting on the steering column shaft during idling etc. Stability is required.
[0003]
Although the rolling bearing has a stable friction torque, it is inferior in vibration absorption, and it is necessary to finish the dimensional accuracy of the housing to which the rolling bearing is fixed and the steering column shaft supported by the rolling bearing with high accuracy. In addition to the expensive point of the bearing itself, there is a problem that the processing cost is increased.
[0004]
A plain bearing made of synthetic resin has the advantages of low cost and excellent vibration absorption compared to the above rolling bearing, but requires an appropriate clearance (bearing gap) between the slide bearing and the steering column shaft. Therefore, there is a problem that a collision sound is generated between the steering column shaft and the bearing due to vibration generated in the steering column shaft, and is transmitted as an unpleasant sound to the driver of the automobile. If the clearance is reduced in order to suppress the occurrence of the collision noise, a stick slip phenomenon occurs, which causes a problem that the stability of the friction torque is hindered.
[0005]
In view of the above, the present applicant firstly supports the load acting on the steering column shaft more smoothly during steering operation (when the steering wheel rotates), and in a state where no load is applied to the steering column shaft during idling or the like. Has proposed a steering column bearing that can absorb vibrations acting on the steering column shaft.
[0006]
A steering column bearing according to the proposal includes an outer bush made of synthetic resin having an outer ring and an inner ring integrally formed with the outer ring, and an inner bush fitted into the inner ring of the outer bush. With this bearing, the roundness of the inner bushing is maintained, and during steering operation (when the steering wheel is rotated), the load acting on the steering column shaft is smoothly supported, and the steering column during idling, etc. In a state where no load is applied to the shaft, vibrations acting on the steering column shaft are absorbed.
[0007]
However, when the bearing is firmly press-fitted into the housing for the purpose of preventing the bearing from being axially disengaged and prevented from rotating in the circumferential direction, the bearing is press-fitted on the outer peripheral surface of the outer ring. However, since the outer ring and the inner ring are connected by a plurality of supporting legs extending in the axial direction, the pressure input is different between the outer peripheral surface of the supporting leg part and the outer peripheral surface between the supporting legs. The pressure input is not evenly applied to the inner bush that is held by the inner peripheral surface and supports the steering column shaft, and there is a problem that the inner dimensional accuracy (roundness) of the inner bush is adversely affected.
[0008]
In addition, when a member (bracket) for fixing the housing to the vehicle body is attached to the outer peripheral surface of the housing by welding, the influence of welding distortion due to welding has an adverse effect on the inner diameter dimensional accuracy (roundness) of the housing. There is also a problem that the inner diameter dimensional accuracy (roundness) of the inner bush of the bearing fixed to the shaft is further deteriorated. When these problems are combined, the inner diameter dimensional accuracy (roundness) of the inner bush of the bearing is further deteriorated. The quality of the inner diameter dimension (roundness) of the inner bush of the bearing affects smooth sliding between the inner bush and the steering column shaft supported by the inner bush. This is a problem that must be avoided as much as possible because it prevents sliding.
[0009]
The present invention has been made in view of the above-described points, and an object of the present invention is to more smoothly support a load acting on the steering column shaft during steering operation (when the steering wheel is rotated), when idling, and the like. For a steering column that can absorb vibrations acting on the steering column shaft without load on the steering column shaft, and that does not adversely affect the dimensional accuracy (roundness) due to the support legs and heat. A bearing and a bearing device using the bearing are provided.
[0010]
[Means for Solving the Problems]
The steering column bearing of the present invention has an inner cylindrical portion in which at least three fastening margins are formed on the inner surface and grooves are formed on the outer surface corresponding to the fastening margin portions, and is concentric with the inner cylindrical portion. And an elastic cylindrical body integrally having an outer cylindrical portion arranged outside the inner cylindrical portion so as to form an annular recess with the inner cylindrical portion.
[0011]
The steering column bearing of the present invention is further provided with a rigid annular shape in which the inner surface is disposed on the outer surface of the inner cylindrical portion, the outer surface is in contact with the inner surface of the outer cylindrical portion, and is disposed in the annular recess so as to cover the groove. Has a body.
[0012]
In the steering column bearing according to the present invention, the inner surface of the inner cylindrical portion includes a pair of large-diameter inner surfaces and a small-diameter inner surface positioned between the pair of large-diameter inner surfaces. The part is formed.
[0013]
In the bearing device of the present invention using the above-described steering column bearing, the steering column bearing is formed in the housing by elastic deformation of a plurality of protruding ridges extending in the axial direction formed on the outer surface of the outer cylindrical portion. The steering column shaft is supported by being slidably brought into sliding contact with the inner surface of the inner cylindrical portion at least at the tightening margin.
[0014]
In the bearing device according to the present invention, the housing includes at least one tongue piece, and the tongue piece at least partially bites into the convex portion on the outer surface of the outer cylindrical portion, and the steering column from the housing. Prevents the bearings from coming out.
[0015]
Examples of the material of the elastic cylindrical body include a rubber elastic body and a synthetic resin having elasticity, but the synthetic resin having elasticity is flexible and tough, and generally has a Shore hardness (D type). 40 to 60, rebound resilience value (JIS-K6301) having 50 to 80, and rubber-like elastic behavior remains, for example, a polyester-ether copolymer or polyurethane is cited as a preferred example. Can do.
[0016]
As a rigid toric body, a metal, especially steel, a copper alloy, an aluminum alloy, a fiber reinforced resin, a sintered metal, etc. can be mentioned as a preferable example.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail based on preferred embodiments shown in the drawings. The present invention is not limited to the following examples.
[0018]
【Example】
1 to 3, a steering column bearing device 1 of this example includes a steering column bearing 3 that supports a steering column shaft 2, and a pipe-like housing 4 into which the steering column bearing 3 is press-fitted and fixed. is doing.
[0019]
The steering column bearing 3 includes an elastic cylindrical body 11 formed of a rubber elastic body or an elastic synthetic resin.
[0020]
The elastic cylindrical body 11 is formed with at least three fastening margins 16, 17, 18 and 19 in the inner surface 15 in this example, and each of the clamping margins 16, 17, 18 and 19 on the outer surface 20. Corresponding to the inner cylindrical portion 25 formed with the axially extending grooves 21, 22, 23 and 24, and the inner cylindrical portion 25 concentric with the inner cylindrical portion 25. Are formed integrally with one end face of the outer cylindrical portion 27 and the outer cylindrical portion 27 disposed outside the inner cylindrical portion 25 and larger than the outer cylindrical portion 27. An annular connecting portion 28 having an outer diameter is integrally provided.
[0021]
Each of the four tightening margins 16 to 19 is arranged symmetrically with respect to the axis and formed flat. For example, when the diameter r of the steering column shaft 2 is 25.00 mm, the tightening margins 16 and 18 Preferably, the interval L and the interval L between the tightening margins 17 and 19 are each shorter than the diameter r by about 0.01 mm to 0.10 mm, that is, L = 24.99 mm to 24.90 mm. , L = 24.95 mm.
[0022]
Each of the grooves 21 to 24 is closed by the annular connecting portion 28 at one end side in the axial direction, and is open to the outside at the other end side.
[0023]
The inner cylindrical portion 25 has a pair of large-diameter inner surfaces 31 and 32 and a small-diameter inner surface 33 positioned between the pair of large-diameter inner surfaces 31 and 32 in the axial direction on the inner surface 15. Fastening margins 16 to 19 are formed. For example, when the diameter r of the steering column shaft 2 is 25.00 mm, the small-diameter inner surface 33 has a diameter R excluding the interference portions 16 to 19 larger than the diameter r by about 0.10 mm to 0.30 mm. In other words, it is formed so that R = 25.5 mm to 25.30 mm, and preferably R = 25.55 mm.
[0024]
The outer cylindrical portion 27 is formed with a plurality of sawtooth-shaped protruding strips 42 extending in the axial direction on the outer surface 41 thereof, and the steering column bearing 3 is press-fitted into the housing 4 by the elastic deflection of the protruding strips 42. Yes. In order to prevent the steering column bearing 3 from coming out of the housing 4, it is preferable that the protruding portion 42 is sufficiently bent and press-fitted into the housing 4. However, the protruding portion 42 is excessively bent. In addition, the roundness of the inner surface 15 of the inner cylindrical portion 25 may be affected. For this reason, in order to prevent the steering column bearing 3 from coming out of the housing 4 even if the ridge 42 is not sufficiently bent, the tongue piece 45 is formed in advance in the housing 4 by cutting or the like, and the steering column After the press-fit of the bearing 3 for the housing 3 into the housing 4, the tongue piece 45 may be partially bitten into the ridge 42. The tongue piece 45 may be bent in the central direction in advance before the steering column bearing 3 is press-fitted into the housing 4 and partially bite into the convex portion 42 together with the press-fitting. Further, it may be bent in the center direction so as to partially bite into the ridge 42. Moreover, although only one tongue piece 45 may be provided in the housing 4, a plurality of tongue pieces 45 may be provided in the circumferential direction.
[0025]
In the steering column bearing device 1 described above, when the steering column bearing 3 is press-fitted into the housing 4, the reduced diameter of the outer cylindrical portion 27 is not transmitted to the inner cylindrical portion 25 through the annular recess 26. As a result of reliably maintaining the inner diameter dimensional accuracy (roundness) of the inner surface 15 of the inner cylindrical portion 25, an appropriate clearance (sliding gap) is provided between the inner surface 15 of the inner cylindrical portion 25 and the steering column shaft 2. It is maintained and smooth sliding of the steering column shaft 2 can be obtained without causing problems such as one-side contact.
[0026]
Further, in the steering column bearing device 1, since the grooves 21 to 24 are provided corresponding to the tightening margins 16 to 19, the steering column shaft 2 inserted into the inner surface 15 of the elastic cylindrical body 11 serves as the tightening margin. It is rotatably supported by appropriate elastic clamping of the inner cylindrical portion 25 at 16-19. Therefore, in a state where no load is applied to the steering column shaft 2 at the time of idling or the like, the steering column shaft 2 is elastically supported by the inner cylindrical portion 25 in the tightening margins 16 to 19, so that the vibration acting on the steering column shaft 2 is not affected. Absorption of the collision noise between the steering column shaft 2 and the inner cylindrical portion 25 is prevented, and the load acting on the steering column shaft 2 during the steering operation is applied to the inner cylindrical portion 25 with the appropriate clearance (sliding). It will be supported smoothly with a moving gap).
[0027]
As shown in FIGS. 4 and 5, the steering column bearing 3 may further include an annular body 12 formed of a rigid material such as steel.
[0028]
The steel annular body 12 has an annular concave shape so that the inner surface 51 is in contact with the outer surface 20 of the inner cylindrical portion 25 and the outer surface 52 is in contact with the inner surface 53 of the outer cylindrical portion 27 and covers the upper surfaces of the grooves 21 to 24. The place 26 is arranged. The annular body 12 may be disposed in the annular recess 26 together with the integral molding of the elastic cylindrical body 11, but may be disposed by being press-fitted into the annular recess 26 after the integral molding of the elastic cylindrical body 11. Good.
[0029]
According to the steering column bearing 3 shown in FIGS. 4 and 5, when the steering column bearing 3 is press-fitted into the housing 4, the transmission of the outer cylindrical portion 27 to the inner cylindrical portion 25 with a reduced diameter is rigid. Since the inner diameter dimensional accuracy (roundness) of the inner surface 15 of the inner cylindrical portion 25 is more reliably maintained because it is more reliably prevented by the annular body 12, the inner surface 15 of the inner cylindrical portion 25 and the steering column shaft An appropriate clearance (sliding gap) is more stably and reliably maintained between the steering column shaft 2 and the steering column shaft 2 can be smoothly slid without causing problems such as a single contact.
[0030]
【The invention's effect】
According to the present invention, a load acting on the steering column shaft is more smoothly supported during steering operation (when the steering wheel is rotated), and the steering column shaft is in a state where no load is applied to the steering column shaft during idling or the like. Further, it is possible to provide a steering column bearing capable of absorbing the vibration acting on the bearing and eliminating the adverse effect on the accuracy of the inner diameter dimension (roundness) due to the support legs and heat, and a bearing device using this bearing. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along the line I-I shown in FIG. 2 of a preferred embodiment of the present invention.
2 is a sectional view taken along line II-II of the embodiment shown in FIG.
FIG. 3 is a plan view of the embodiment shown in FIG. 1;
4 is a cross-sectional view taken along the line IV-IV shown in FIG. 5 of another preferred embodiment of the present invention.
5 is a cross-sectional view taken along line VV of the embodiment shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steering column bearing apparatus 2 Steering column shaft 3 Steering column bearing 4 Housing 11 Elastic cylinder 15 Inner surface 16, 17, 18, 19 Tightening part 20 Outer surface 21, 22, 23, 24 Groove 25 Inner cylindrical part 26 Toroidal Recess 27 Outer cylindrical part

Claims (1)

  An inner cylindrical portion in which at least three flat fastening portions are formed on the inner surface and a groove is formed on the outer surface corresponding to the fastening margin portion. The inner cylindrical portion is disposed concentrically with the inner cylindrical portion. An outer cylindrical portion disposed outside the inner cylindrical portion so as to form an annular recess therebetween, and an annular coupling portion integrally formed on one end surface of each of the inner cylindrical portion and the outer cylindrical portion. An elastic cylinder made of polyester / ether copolymer or polyurethane, an inner surface is in contact with the outer surface of the inner cylindrical portion, and an outer surface is in contact with the inner surface of the outer cylindrical portion and covers the groove. A bearing device using a steering column bearing having a rigid annular body disposed in an annular recess, the inner surface of the inner cylindrical portion includes a pair of large-diameter inner surfaces and the pair of large-diameters With a small-diameter inner surface located between the inner surfaces In the axial direction, each of the grooves is closed at one end side by an annular connecting portion and open at the other end side to the outside. The annular body is made of steel, copper alloy, aluminum alloy, fiber reinforced resin, or sintered metal, and a plurality of ridges extending in the axial direction are formed on the outer surface of the outer cylindrical portion that is press-fitted into the housing. The steering column bearing is formed by being press-fitted into the housing by elastic deformation of the ridges and supported by sliding the steering column shaft on the inner surface of the inner cylindrical portion at least at the tightening margin. At least one tongue piece, and the tongue piece bites into the convex portion of the outer surface of the outer cylindrical portion at least partially. Bearing apparatus using a bearing for a steering column is prevented coming off.

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