STRUCTURE FOR ATTACHING A SWITCH BODY TO A STEERING COLUMN TUBE

Abstract

A structure for attaching a switch body to a steering column tube, includes a switch body attached to a steering column tube of a vehicle, an adaptor intervening between the switch body and the steering column tube of the vehicle and having a first engaging portion engaged with a locking portion of the steering column tube as well as a second engaging portion engaged with a locking portion of the switch body. The first engaging portion of the adaptor is engaged with the locking portion of the steering column tube, and at the same time, the second engaging portion of the adaptor is engaged with the locking portion of the switch body by pushing the switch body toward the steering column tube side of the vehicle.

Description

The present application is based on Japanese Patent Application No. 2007-261707 filed on Oct. 5, 2007, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structure for attaching a switch body to a steering column tube, in more particular, to a structure in which a switch body can be easily attached to a steering column tube.

2. Related Art

A switch body mounting a light switch, a wiper switch or the like is attached at an edge of a column tube which supports a steering shaft of a vehicle. As this type of attachment structure, for example, there is disclosed a configuration in which an attachment portion extending outwards from a rim of an open hole letting a steering column tube penetrate is extendingly formed on a lower surface of a switch body and a ring-shaped clamping band is fitted over the attachment portion. The clamping band is a member in which a spring force acts in a diameter-reducing direction and a diameter-expanded state is kept by locking both edges thereof to a holding portion on the lower surface of the switch body.

According to the above-mentioned structure, when attaching a switch body to a steering column tube, the switch body is temporarily fixed to the steering column tube by firstly letting the steering column tube through an insertion opening of the switch body. When pulling the holding portion toward the near side in this state, the diameter-expanded state of the clamping band by the holding portion is released since a temporarily locked state of the both edges of the clamping band with the holding portion is released. Therefore, since the clamping band reduces a diameter by a spring force thereof, the clamping band strongly presses an assembly portion of the switch body against the steering column tube from the periphery, as a result, the switch body is fixed to the steering column tube.

Patent document 1 JP-A-5-44609U

However, when pressing the switch body against the steering column tube by the clamping band during switch body attachment, an operation to pull the holding member toward the near side is required in order to release the temporarily locked state of the clamping band, thus, there was a problem that the amount of man-hours increases and an efficiency of switch body attachment is poor. Furthermore, the switch body may be attached to a position where is hard to see from a worker, therefore, there was a countermeasure requirement also from a viewpoint of workability and working efficiency.

THE SUMMARY OF THE INVENTION

Therefore, it is an object of the invention to provide a structure for attaching a switch body by which the switch body can be easily attached to a steering column tube with a single operation.

According to a feature of the present invention, a structure for attaching a switch body to a steering column tube comprises:

• • a switch body attached to a steering column tube of a vehicle;
  • an adaptor intervening between the switch body and the steering column tube of the vehicle and having a first engaging portion engaged with a locking portion of the steering column tube as well as a second engaging portion engaged with a locking portion of the switch body,
    • wherein the first engaging portion of the adaptor is engaged with the locking portion of the steering column tube, and at the same time, the second engaging portion of the adaptor is engaged with the locking portion of the switch body by pushing the switch body toward the steering column tube side of the vehicle.

The switch body may be attached by being temporarily assembled with the adaptor and being pushed into the steering column tube in this temporarily assembled state.

The first engaging portion of the adaptor may be a metal clip attached by fixing to a predetermined position of the adaptor.

According to present invention, it is possible to provide a structure for attaching a switch body by which the switch body can be attached easily to a steering column tube with a single operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Next, the present invention will be explained in more detail in conjunction with appended drawings, wherein:

FIG. 1 is a perspective view showing a structure for attaching a switch body to a steering column tube in a first preferred embodiment according to the present invention;

FIG. 2 is a revolved section showing the structure for attaching a switch body to a steering column tube shown in FIG. 1 when viewed from A-A direction in FIG. 1;

FIG. 3 is a cross sectional view showing a temporarily assembled state of a switch body 10, a spring 30 and an adaptor 20;

FIG. 4A and FIG. 4B are cross sectional views showing a state of attachment to a steering column tube 100, wherein FIG. 4A is a state before attaching and FIG. 4B is a state after attaching; and

FIG. 5A is a cross sectional view showing a structure for attaching a switch body to a steering column tube in a second preferred embodiment according to the present invention which corresponds to FIG. 2, FIG. 5B is a cross sectional view showing a structure for attaching a switch body to a steering column tube in a third preferred embodiment according to the present invention which corresponds to FIG. 2 and FIG. 5C is a cross sectional view showing a structure for attaching a switch body to a steering column tube in a fourth preferred embodiment according to the present invention which corresponds to FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

First Preferred Embodiment According to the Present Invention

FIG. 1 is a perspective view showing a structure for attaching a switch body to a steering column tube in a first preferred embodiment according to the present invention. FIG. 2 is a revolved section showing the structure for attaching a switch body to a steering column tube shown in FIG. 1 when viewed from A-A direction in FIG. 1. FIG. 3 is a cross sectional view showing a temporarily assembled state of a switch body 10, a spring 30 and an adaptor 20. FIG. 4A and FIG. 4B are cross sectional views showing a state of attachment to a steering column tube 100, wherein FIG. 4A is a state before attaching and FIG. 4B is a state after attaching.

As shown in FIG. 1, a structure for attaching a switch body to a steering column tube in the first preferred embodiment according to the present invention comprises a switch body 10 attached to a steering column tube 100 of a vehicle and an adaptor 20 intervening between the switch body 10 and the steering column tube 100 of the vehicle, in which the switch body 10 is attached by being pushed in a state that the adaptor 20 is intervening between the switch body 10 and the steering column tube 100 mounted on the vehicle side. After the switch body 10 is attached to the steering column tube 100, a non-illustrated roll connector for electrically connecting electrical components mounted on the switch body 10 such as various switches or the like with the vehicle side is mounted while allowing rotation of a non-illustrated steering wheel, furthermore, the steering wheel provided with a non-illustrated core bar is attached to a steering shaft 101.

(Switch Body 10)

The switch body 10 is provided with a turn lever 11 for a turn signal on a right surface in a state of being rotatable in an upward-downward direction and a forward/reverse direction about a proximal end as a fulcrum. When the turn lever 11 is operated to an upper side or a lower side from a neutral position, a connection state of a non-illustrated turn lever switch in the switch body 10 is shifted and a turn signal is emitted corresponding to a lever operation. Furthermore, a wiper operation lever 12 is provided on a left surface in a state of being rotatable in an upward-downward direction about a proximal end as a fulcrum. When the wiper operation lever 12 is pushed downwards from an initial position, the connection state of a non-illustrated wiper operation switch in the switch body 10 is shifted and a wiper is operated corresponding to a lever operation.

A cylindrical-shaped attachment portion 13 fitted with the adaptor 20 is provided in a protruding condition on a side where the switch body 10 is attached to the steering column tube 100. Three snap pressing portions 13a are formed on this attachment portion 13 in a circumferential direction, which is a portion to push down a below-described snap claw 21 formed on the adaptor 20 and is formed having a step 13d so as to push down the snap claw 21 easily as shown in FIG. 2, furthermore, the step 13d is formed in the circumferential direction with a predetermined width so that the snap claw 21 is fitted. The above-mentioned step 13d is not an essential shape, it is acceptable as long as it is a locking structure in which the snap claw 21 can be pushed down and a movement relative to the snap claw 21 in the circumferential direction is not allowed, for example, it may be a structure that a concave portion or a hole is formed on an inner circumference of the attachment portion 13 for engaging with the snap claw 21 or a portion thereof.

Three locking portions 13b are formed between respective intervals in the circumferential direction of the above mentioned attachment portion 13. In the locking portion 13b, as shown in FIG. 2, a slit 13c is formed along an axial direction of the cylindrical-shaped attachment portion 13, as a result, it is possible to deflect in a radial direction and a locking claw 13e as a locking portion locked by fitting into a hole 20a or a notch 20b of the adaptor 20 is formed on the inner circumference.

Furthermore, a snap ring groove 13f for fitting a spring 30 is formed in the cylindrical-shaped attachment portion 13 so as to facilitate a positioning of the spring 30 and temporary assembly with the adaptor 20.

In this embodiment, the switch body 10 is mainly formed of a resin (for example, an ABS resin or the like) and the cylindrical-shaped attachment portion 13 is formed by being integrally molded, however, it may be formed by assembling two or more parts. Furthermore, the cylindrical-shaped attachment portion 13 may be configured to be independent as a separate member, to be attached to the steering column tube 100 via the adaptor 20 and to attach the switch body 10 to the attachment portion 13 as this separate member with a screw or the like, for example.

(Adaptor 20)

The adaptor 20 is in a cylindrical shape with steps and the three snap claws 21 are formed as the first engaging portion thereon in the circumferential direction. This snap claw 21 is allowed to deflect in a radial direction, is formed so as to be located in a peripheral direction of the adaptor 20 in the initial state, as shown in FIG. 2 and has a wedge-shaped convex portion 21a fitting into a concave portion 100a formed on the below-described steering column tube 100.

Furthermore, three holes 20a and three notches 20b are formed as the second engaging portion between respective intervals in the circumferential direction of the above-mentioned three snap claws 21. The locking claw 13e is fitted into the hole 20a in the temporarily assembled state and is fitted into the notch 20b in a state of being attached to the steering column tube 100.

The adaptor 20 is formed of a resin or a metal, however, it may be integrally formed with the snap claw 21 or the like formed of a separate member. The configuration in which he snap claw 21 is formed with a separate member will be shown in below-described third and fourth embodiments.

(Steering Column Tube 100)

In the steering column tube 100, the steering shaft 101 is rotatably supported at a center in a state of being attached to a vehicle side. Three concave portions 100a for fitting the snap claw 21 of the adaptor 20 are formed on the steering column tube 100. A steering wheel provided with a non-illustrated core bar is attached to a steering shaft 101 so as to penetrate an inner space of the adaptor 20.

(Temporary Assembly of Switch Body 10, Adaptor 20 and Spring 30)

The switch body 10, the adaptor 20 and the spring 30 are temporarily assembled before being attached to the steering column tube 100. As shown in FIG. 3, the switch body 10 is temporarily assembled with the adaptor 20 via the spring 30 between them. The three locking claws 13e on the switch body 10 side are fitted into the hole 20a on the adaptor 20 side. In this temporarily assembled state, since the spring 30 imparts a biasing force in a direction to separate the switch body 10 and the adaptor 20, there is no backlash between the switch body 10 and the adaptor 20 and it is possible to push down the adaptor 20 in a direction of the switch body 10.

Three of the above-mentioned snap pressing portions 13a, the locking portions 13b and the locking claws 13e formed on the attachment portion 13, the convex portions 21a and the notches 20b formed on the adaptor 20 and the concave portions 100a formed on the steering column tube 100 are provided respectively, however, it is not limited thereto, it is acceptable as long as the attachment portion 13, the adaptor 20 and the steering column tube 100 are fixed each other and a design change for the above-mentioned number of each parts is possible.

(Attachment to Steering Column Tube 100)

FIG. 4A shows an assay product in a state that the switch body 10, the adaptor 20 and the spring 30 are temporarily assembled, which is a preparatory state for being attached to the steering column tube 100. An attachment operation is carried out by pushing the assay product of the temporarily assembled state in a direction of the steering column tube 100 from this state.

FIG. 4B shows a state that the assay product in the temporarily assembled state of the switch body 10, the adaptor 20 and the spring 30 is attached by being pushed toward the steering column tube 100 side. When pushing the switch body 10 temporarily assembled with the adaptor 20 toward the steering column tube 100 side, the adaptor 20 is inserted toward the steering column tube 100 side and the snap claw 21 comes close to the concave portion 100a. At the same time, the distance between the switch body 10 and the adaptor 20 decreases and the snap claw 21 is pushed down in an inner peripheral direction by the snap pressing portion 13a. When further pushing the switch body 10 toward the steering column tube 100 side, the convex portion 21a of the adaptor 20 is fitted into the concave portion 100a, is further pushed strongly against the attachment portion 13 in the inner peripheral direction and is fixed due to a locked state of the adaptor 20 with the steering column tube 100.

Meanwhile, as for the switch body 10 side, the locking claw 13e fitted with the hole 20a of the adaptor 20 is locked by fitting into the notch 20b after sliding onto the outer periphery of the attachment portion 13 from the hole 20a. In this locked state, the switch body 10 is locked in an axial direction and a circumferential direction, and then, fixed.

The switch body 10 and the adaptor 20 are integrally attached to the steering column tube 100, locked in the axial direction and the circumferential direction and fixed by the above-mentioned attachment operation.

The structure for attaching a switch body to a steering column tube in the first preferred embodiment according to the present invention has following effects.

(1) An easy attachment with a single operation is possible by pushing the switch body 10 into the steering column tube 100.

(2) Since it is possible to carry out the attachment operation to the steering column tube 100 in a state that the switch body 10, the adaptor 20 and the spring 30 are temporarily assembled, a structure for attaching a switch body with excellent workability is realized.

(3) Since the switch body 10 is temporarily assembled with the adaptor 20 via the spring 30, there is no backlash between the switch body 10 and the adaptor 20, the attachment operation to the steering column tube 100 is facilitated and the workability is improved.

Second Preferred Embodiment According to the Present

FIG. 5A is a cross sectional view showing a structure for attaching a switch body to a steering column tube in a second preferred embodiment according to the present invention which corresponds to FIG. 2. In this second preferred embodiment, the switch body 10 is temporarily assembled with the adaptor 20 omitting the spring 30. Although certain backlashes are generated between the switch body 10 and the adaptor 20 in the temporarily assembled state, there is no significant obstacle for the attachment operation to the steering column tube 100 and there is an effect to reduce the cost.

Third Preferred Embodiment According to the Present

FIG. 5B is a cross sectional view showing a structure for attaching a switch body to a steering column tube in a third preferred embodiment according to the present invention which corresponds to FIG. 2. In this third preferred embodiment, the switch body 10 is temporarily assembled with the adaptor 20 omitting the spring 30. Furthermore, in the adaptor 20, a metal clip 22 is formed of a separate member and is attached to the adaptor 20. The metal clip 22 can be made by an insert molding when molding the adaptor 20, and also can be attached to the adaptor 20 by press fitting or screw cramp after molding the adaptor 20. A lock function same as the first preferred embodiment is exerted by attaching the metal clip 22 to the adaptor 20 instead of the snap claw 21. According to the third preferred embodiment, the cost is reduced as the spring 30 is omitted and the attachment strength, improvement of design freedom or the like are sought by the metal clip 22.

Fourth Preferred Embodiment According to the Present

FIG. 5C is a cross sectional view showing a structure for attaching a switch body to a steering column tube in a fourth preferred embodiment according to the present invention which corresponds to FIG. 2. In this fourth preferred embodiment, a metal clip 22 is formed of a separate member and is attached to the adaptor 20. The metal clip 22 can be made by an insert molding when molding the adaptor 20, and also can be attached to the adaptor 20 by press fitting or screw cramp after molding the adaptor 20. A lock function same as the first preferred embodiment is exerted by attaching the metal clip 22 to the adaptor 20 instead of the snap claw 21. According to the fourth preferred embodiment, in the adaptor 20, since the switch body 10 is temporarily assembled with the adaptor 20 via the spring 30 between them, there is no backlash between the switch body 10 and the adaptor 20, the attachment operation to the steering column tube 100 is facilitated and the workability is improved. Furthermore, the attachment strength, improvement of design freedom or the like are sought by the metal clip 22.

Although the invention has been described with respect to the specific embodiments for complete and clear disclosure, the appended claims are not to be therefore limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.

Claims

1. A structure for attaching a switch body to a steering column tube, comprising: a switch body attached to a steering column tube of a vehicle;an adaptor intervening between the switch body and the steering column tube of the vehicle and having a first engaging portion engaged with a locking portion of the steering column tube as well as a second engaging portion engaged with a locking portion of the switch body,wherein the first engaging portion of the adaptor is engaged with the locking portion of the steering column tube, and at the same time, the second engaging portion of the adaptor is engaged with the locking portion of the switch body by pushing the switch body toward the steering column tube side of the vehicle.

2. The structure for attaching a switch body to a steering column tube according to claim 1, wherein the switch body is attached by being temporarily assembled with the adaptor and being pushed into the steering column tube in this temporarily assembled state.

3. The structure for attaching a switch body to a steering column tube according to claim 1, wherein the first engaging portion of the adaptor is a metal clip attached by fixing to a predetermined position of the adaptor.

4. The structure for attaching a switch body to a steering column tube according to claim 1, wherein the first engaging portion of the adaptor is a snap claw allowed to deflect in a radial direction, formed so as to be located in a peripheral direction of the adaptor in the initial state and formed in a circumferential direction as a wedge-shaped convex portion fitted into a concave portion formed on the steering column tube.

5. The structure for attaching a switch body to a steering column tube according to claim 4, wherein a cylindrical-shaped attachment portion fitted with the adaptor is provided in a protruding condition in the switch body and a snap pressing portion for pressing the snap claw of the adaptor is formed in the circumferential direction of the attachment portion.

6. The structure for attaching a switch body to a steering column tube according to claim 4, wherein the switch body is integrally formed of the attachment portion and a locking portion with a locking claw by resin molding.

7. The structure for attaching a switch body to a steering column tube according to claim 4, wherein the switch body has a slit formed along an axial direction of the attachment portion and the locking portion locked to the adaptor between respective intervals in a circumferential direction of the attachment portion.

8. The structure for attaching a switch body to a steering column tube according to claim 4, wherein a snap ring groove for fitting a spring into the attachment portion is formed on the switch body.

9. The structure for attaching a switch body to a steering column tube according to claim 4, wherein the second engaging portion of the adaptor comprises a hole to which the locking claw is fitted in a temporarily assembled state and a notch to which the locking claw is fitted in a state of being attached to the steering column tube between respective intervals in a circumferential direction of the snap claw.

10. The structure for attaching a switch body to a steering column tube according to claim 9, wherein the temporary assembly of the switch body with the adaptor means a temporarily assembled state in which the locking claw on the switch body side is fitted into the hole on the adaptor side via a spring between the switch body and the adaptor.