JP6973222B2 - Intermediate shaft - Google Patents

Description

The present invention relates to an intermediate shaft for preventing the dust cover from coming off of vehicle steering.

As a conventional technique, in an intermediate shaft for vehicle steering that is arranged through the dash panel (arranged over the inside and outside of the vehicle interior), the intermediate shaft is used when assembling the dust cover, which is a component for closing the hole of the dash panel, to the vehicle. The dust cover can be slid in the axial direction to adjust the axial position.
Therefore, there is an intermediate shaft that prevents the intermediate shaft from coming off (falling off) from the tube side to the shaft side during assembly to the vehicle.

For example, Patent Document 1 describes a steering device in which a tubular dust seal cover attached to the outer periphery of an intermediate portion of an intermediate shaft is fitted to an annular seal portion of a column hole cover assembled to a vehicle. A locking portion is disclosed in which a part of the outer cylinder is projected outward.
Further, Patent Document 2 describes the axial movement of the dust cover outerly fitted to the inner shaft with the tip of a screw screwed into a screw hole existing at one position in the circumferential direction of the stopper ring and the screw of the stopper ring. A stopper ring for the inner shaft is disclosed by screwing in a manner in which the inner shaft is sandwiched between a portion located on the opposite side in the radial direction with respect to the hole.

Japanese Unexamined Patent Publication No. 08-156807 JP-A-2017-75649

However, in the above-mentioned intermediate shaft with a dust cover of the prior art, an auxiliary part such as a stopper ring for preventing the dust cover from falling off and a retaining portion for preventing the shaft from coming out of the tube are separately provided. Therefore, there is a problem that the parts cost, the assembly cost and the weight are also increased.
Therefore, in view of the above circumstances, the present invention does not increase the parts cost, assembly cost and weight, and has a configuration for preventing the dust cover from being pulled out from the tube and the shaft from being pulled out until the vehicle is assembled. It provides an intermediate shaft that has fewer elements and is simpler.

The first intermediate shaft of the present invention is an intermediate shaft with a dust cover arranged in a state of inserting a through hole provided in a dash panel of a vehicle, and the intermediate shaft is a circle having a male groove on the outer periphery. A cylindrical shaft having a columnar shaft portion and a female groove outerly fitted to the male groove of the shaft portion on the inner circumference, and an outer peripheral surface of the intermediate shaft and an inner peripheral surface of the through hole which are outerly fitted to the tube. It has an annular dust cover for closing the gap between the tube and the tube, and at one end in the axial direction of the tube, a first protrusion for preventing the dust cover from coming out of the tube and a shaft portion. It is provided with a second protrusion, which prevents the tube from coming out of the tube.
In the first invention, the intermediate shaft of the second invention is provided with at least one of the first protrusions integrally on a part of the outer diameter side of the tube, and the second protrusions of the tube. At least one is integrally provided on a part of the inner diameter side.
In the first invention or the second invention, the intermediate shaft of the third invention is integrally provided with the first protrusion and the second protrusion at the same position on one side end portion in the axial direction of the tube. There is.
In any one of the first to third inventions, the intermediate shaft of the fourth invention is a spline fitting between the shaft portion and the tube.
In any one of the first to third inventions, the intermediate shaft of the fifth invention is a serration fitting between the shaft portion and the tube.
In any one of the first to fifth inventions, the intermediate shaft of the sixth invention has a rolling element interposed between the inner peripheral surface of the cylindrical portion of the tube and the outer peripheral surface of the cylindrical portion of the shaft portion.

According to the intermediate shaft of the present invention, the parts cost, the assembly cost and the weight are not increased, and the number of components for preventing the dust cover from being pulled out from the tube and the shaft from being pulled out is reduced until the vehicle is assembled. It can provide an intermediate shaft that is simply realized.

It is a schematic diagram of the steering device of this embodiment. It is a perspective view of the steering apparatus of this embodiment. It is a perspective view of the intermediate shaft of this embodiment. (A) is a cross-sectional view seen from the line AA of FIG. 3, and (b) is a cross-sectional view seen from the line BB. It is a partially enlarged sectional view of the main part of the intermediate shaft of this embodiment. It is a partial cross-sectional view which attached the dust cover of this embodiment to an intermediate shaft.

Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments for carrying out the following inventions (hereinafter referred to as embodiments). Further, the components in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that are in a so-called equal range. Further, the components disclosed in the following embodiments can be appropriately combined.

(Embodiment)
FIG. 1 is a schematic view of the steering device of the present embodiment. FIG. 2 is a perspective view of the steering device of the present embodiment. As shown in FIG. 1, the steering device 80 includes a steering wheel 81, a first steering shaft 82, a steering force assist mechanism 83, a first universal joint 84, a second steering shaft 85, and a second universal joint 86. And is joined to the third steering shaft 87. In the following description, the front in the vehicle equipped with the steering device 80 is simply described as front, and the rear in the vehicle is simply described as rear.

As shown in FIG. 1, the first steering shaft 82 includes an input shaft 82a and an output shaft 82b. One end of the input shaft 82a is connected to the steering wheel 81 and the other end of the input shaft 82a is connected to the output shaft 82b. Further, one end of the output shaft 82b is connected to the input shaft 82a, and the other end of the output shaft 82b is connected to the first universal joint 84.

As shown in FIG. 1, the second steering shaft 85 connects the first universal joint 84 and the second universal joint 86. One end of the second steering shaft 85 is connected to the first universal joint 84 and the other end is connected to the second universal joint 86. One end of the third steering shaft 87 is connected to the second universal joint 86, and the other end of the third steering shaft 87 is connected to the steering gear 88. As shown in FIG. 2, the second steering shaft 85 penetrates the dash panel 10. The dash panel 10 is a partition plate that separates the vehicle interior and the engine room.

As shown in FIG. 1, the steering gear 88 includes a pinion 88a and a rack 88b. The pinion 88a is connected to the third steering shaft 87. The rack 88b meshes with the pinion 88a. The steering gear 88 converts the rotational motion transmitted to the pinion 88a into a straight motion by the rack 88b. The rack 88b is connected to the tie rod 89. The angle of the wheel changes as the rack 88b moves.

As shown in FIG. 1, the steering force assist mechanism 83 includes a speed reducing device 92 and an electric motor 93. The speed reducer 92 is, for example, a worm speed reducer. The torque generated by the electric motor 93 is transmitted to the worm wheel via the worm inside the speed reducer 92 to rotate the worm wheel. The speed reducer 92 increases the torque generated by the electric motor 93 by the worm and the worm wheel. Then, the speed reducing device 92 applies an auxiliary steering torque to the output shaft 82b. That is, the steering device 80 is a column assist system.

As shown in FIG. 1, the steering device 80 includes an ECU (Electronic Control Unit) 90, a torque sensor 94, and a vehicle speed sensor 95. The electric motor 93, the torque sensor 94, and the vehicle speed sensor 95 are electrically connected to the ECU 90. The torque sensor 94 outputs the steering torque transmitted to the input shaft 82a to the ECU 90 by CAN (Control Area Network) communication. The vehicle speed sensor 95 detects the traveling speed (vehicle speed) of the vehicle body on which the steering device 80 is mounted. The vehicle speed sensor 95 is provided on the vehicle body and outputs the vehicle speed to the ECU 90 by CAN communication.

The ECU 90 controls the operation of the electric motor 93. The ECU 90 acquires signals from each of the torque sensor 94 and the vehicle speed sensor 95. Power is supplied to the ECU 90 from the power supply device 99 (for example, an in-vehicle battery) with the ignition switch 98 turned on. The ECU 90 calculates the auxiliary steering command value based on the steering torque and the vehicle speed. The ECU 90 adjusts the electric power value supplied to the electric motor 93 based on the auxiliary steering command value. The ECU 90 acquires information on the induced voltage from the electric motor 93 or information output from a resolver or the like provided in the electric motor 93. By controlling the electric motor 93 by the ECU 90, the force required to operate the steering wheel 81 is reduced.

FIG. 3 is a perspective view of the second steering shaft (referred to as “intermediate shaft” in the following description) 85 of the present embodiment. The intermediate shaft 85 is an intermediate shaft 85 with a dust cover arranged in a state of inserting a through hole provided in the dash panel 10 of the vehicle, and is an outer peripheral surface 85a of the intermediate shaft 85 and an inner peripheral surface of the through hole. It is provided with an annular dust cover 3 for closing the gap between the two.

The intermediate shaft 85 is required to have a performance of absorbing the axial displacement generated when the automobile travels and not transmitting the displacement or vibration on the steering wheel.
Therefore, as shown in FIG. 4B, the intermediate shaft 85 in the present embodiment has a cylindrical shaft portion 2 having a male groove 24 on the outer periphery and a female that externally fits the male groove 24 of the shaft portion 2. It has a cylindrical tube 1 having a groove 12 on the inner circumference, and an annular dust cover 3 that is fitted onto the tube 1 and for closing the gap between the outer peripheral surface of the intermediate shaft 85 and the inner peripheral surface of the through hole. doing.
The female groove 12 and the male groove 24 are spline fitting or serration fitting. In the following description, the mode of spline fitting will be described.

The shaft portion 2 is a cylindrical member made of steel and has a cylindrical portion 21 which is a male spline portion forming a male groove 24 at the front end portion and a non-male spline portion which does not form a male groove 24 at the rear end portion. The portions 22 are integrally provided so as to be adjacent to each other in the axial direction. The outer diameter of the cylindrical portion 21 of the male spline portion (the diameter of the circumscribed circle of the convex portion) is slightly larger (for example, about 0.3 to 2 mm) than the outer diameter of the cylindrical portion 22 which is the non-male spline portion. ..

A tapered (inclined) portion 23 is formed at the rear end of the front cylindrical portion 21 of the shaft portion 2, and is formed at a predetermined chamfer angle α. It is locked with and prevents the shaft portion 2 from coming off.
As shown in FIG. 5, when the chamfer angle of the tapered (tilted) portion 23 is α and the tilt angle of the second projection portion 14 is β, α ≦ β is set.

Further, the tapered portion 23 is configured such that the coated resin, which was originally coated, is stripped off by machining or the like so that the bare metal is exposed, or the resin is formed. It is configured so that the bare metal is exposed during coating. Therefore, since the resin-coated portion does not engage with the second protrusion 14, it is possible to effectively prevent the resin-coated portion from being pressed against and fixed to the second protrusion 14.

Further, the male spline portion forming the male groove 24 in the cylindrical portion 21 of the shaft portion 2 is coated with a non-ferrous material coating material or resin (for example, nylon film) in order to make it slidable.

In the present embodiment, only the male spline portion is coated with resin, but it is sufficient that at least one of the grooves of the male spline portion and the female spline portion is coated.

Further, instead of coating the male spline portion with resin, a rolling element can be used to make the male spline slidable. For example, a ball or a roller, or a rolling element combining a ball and a roller is interposed between the inner peripheral surface of the cylindrical portion 11 of the tube 1 and the outer peripheral surface of the cylindrical portion 21 of the shaft portion 2, which will be described later. As a result, it is possible to reduce the wear of the contact portion between the inner peripheral surface of the cylindrical portion 11 of the tube 1 and the outer peripheral surface of the cylindrical portion 21 of the shaft portion 2, and reduce the frictional resistance.

The tube 1 is a cylindrical member made of steel, and a cylindrical portion 11 of a female spline portion having a female groove 12 slidably fitted with the male groove 24 of the shaft portion 2 on the inner peripheral surface thereof is provided. It has and cannot rotate relative to the shaft portion 2.

When the dust cover 3 is assembled to the vehicle, the dust cover 3 can slide in the axial direction along the cylindrical portion 11 in order to adjust the axial position of the dust cover 3 with respect to the cylindrical portion 11 of the tube 1.

Specifically, the dust cover 3 is fitted onto the cylindrical portion 11 which is the female spline portion of the tube 1, and the inner peripheral surface of the sealing member elastically contacts the cylindrical portion 11 over the entire circumference to form a cylinder. Axial movement along the portion 11 is possible. For this reason, the dust cover 3 moves in the axial direction toward the cylindrical portion 22 which is the non-male spline portion of the shaft portion 2 of the intermediate shaft 85 while the first protrusion 13 raised on the outside is provided and assembled to the vehicle. However, I try not to slip out (drop out).

As described above, at one end of the cylindrical portion 11 in the axial direction, a first protrusion 13 for preventing the dust cover 3 from coming out of the tube 1 and a first protrusion 13 for preventing the shaft portion 2 from coming out of the tube 1 are prevented. It is provided with a second protrusion 14. The shape of the first protrusion 13 is formed substantially the same as the second protrusion 14 with respect to the central axis of the cylindrical portion 11.

In the present embodiment, as shown in FIGS. 4A and 5, the first protrusion 13 forms a recess 13a at the end of the cylindrical portion 11 of the tube 1 by crimping, and this crimping is performed. It is formed at the end of the tube 1 by plastic working with. This crimping process is performed after the dust cover 3 is inserted into the tube 1.

As a result, the intermediate shaft with a dust cover, which is a combination of the intermediate shaft 85 and the dust cover 3, can be prevented from coming off the shaft of the intermediate shaft 85 before being assembled to the vehicle.

When such a dust cover 3 is assembled to a vehicle, as shown in FIG. 6, the dust cover 3 has a configuration for closing a gap between the outer peripheral surface of the intermediate shaft 85 and the inner peripheral surface of the through hole.
The dust cover 3 includes a bellows 31 as a flexible cover body, a bush 32, a seal lip 33 as a seal member, a seal lip 34, and a mounting member 35. The bellows 31, bush 32, seal lip 33, seal lip 34, and mounting member 35 are each formed in an annular shape. The bellows 31 is made of, for example, rubber.

The seal lip 33 is a sealing member that separates the gap between the intermediate shaft 85 and the bush 32 from the engine room, and can prevent foreign matter from entering the inside of the bush 32 from the engine room and the engine from the inside of the bush 32. It is possible to prevent the leakage of grease to the room. Further, the seal lip 33 can suppress the leakage of the sound generated in the engine room to the vehicle interior.

The seal lip 34 is a sealing member that separates the gap between the intermediate shaft 85 and the bush 32 from the vehicle interior, and can prevent grease from leaking from the inside of the bush 32 to the vehicle interior. be. The seal lips 33 and 34 are, for example, nitrile rubber (NBR), and are integrated with the bush 32 by vulcanization adhesion.

When the dust cover 3 is attached to the vehicle, the dash panel 10 includes a tubular member 101, as shown in FIG. The inner peripheral surface of the tubular member 101 faces the outer peripheral surface of the intermediate shaft. The intermediate shaft 85 may move due to adjustment of the position of the steering wheel 81, vibration during traveling, or the like. Therefore, an annular gap is provided between the inner peripheral surface of the tubular member 101 and the outer peripheral surface of the second steering shaft 85. Therefore, in order to close this gap, the steering device 80 includes a dust cover 3.

As shown in FIGS. 4A and 5, the second protrusion 14 has an outer diameter of the end of the tube 1 provided with the first protrusion 13 raised on the inside (shaft 2 side) of the tube 1. A recess 14a is formed by crimping at a position having the same inner diameter as the position of No. 1, and is formed by plastic working by this crimping.

Further, at least one of the first protrusions 13 is integrally provided on a part of the outer diameter side of the tube 1, and at least one of the second protrusions 14 is provided on a part of the inner diameter side of the tube 1. It is provided integrally. The first protrusion 13 and the second protrusion 14 are integrally provided at the same position on one end of the tube 1 in the axial direction. That is, the first protrusion 13 and the second protrusion 14 are used as one protrusion by crimping the dust cover 3 and the shaft portion 2 for both purposes.
Then, as shown in FIG. 4B, two protrusions including the first protrusion 13 and the second protrusion 14 are provided at the upper and lower facing positions of the end portion of the tube 1 (on the drawing). ing.

The crimping process of the first protrusion 13 and the second protrusion 14 is performed after inserting the shaft portion 2 and the dust cover 3 into the tube 1, but since they are in the same position, the first protrusion 13 and the second protrusion 13 and the second Both of the protrusions 14 can be performed at the same time.

As a result, the dust cover 3 and the shaft portion 2 are formed until the vehicle is assembled without increasing the parts cost, the assembly cost and the weight, because the conventional technology has a simpler retaining structure with few retaining components. It is possible to regulate the escape due to the axial movement of.
However, the number of protrusions including the first protrusion 13 and the second protrusion 14 is not limited to two, and may be one or three or more. Further, the position of the protrusion can be provided without being limited to vertically facing each other on the drawing.

As described above, even when the intermediate shaft with the dust cover is transported before being assembled to the vehicle, or in the middle with the dust cover, even if the auxiliary parts for preventing the dust cover from coming off as in the conventional technology are not provided. When the dust cover 3 moves forward along the cylindrical portion 11 of the tube 1 when the shaft is assembled to the vehicle, the front end surface of the dust cover 3 comes into contact with the first protrusion 13 and similarly. When the second protrusion 14 of the tube 1 comes into contact with the tapered portion 23 of the shaft portion 2, the dust cover 3 and the shaft portion 2 can be prevented from moving backward and coming out (falling off).

1 Tube 2 Shaft 3 Dust cover 10 Dash panel 11 Cylindrical part (tube female spline side)
12 Female groove 13 First protrusion 13a Recess 14 Second protrusion 14a Recess 21 Cylindrical part (shaft part male spline side)
22 Cylindrical part (shaft part non-male spline side)
23 Tapered part 24 Male groove 31 Bellows 32 Bush 33 Seal lip 34 Seal lip 35 Mounting member 80 Steering device 81 Steering wheel 82 Steering shaft 82a Input shaft 82b Output shaft 83 Steering force assist mechanism 84 1st universal joint 85 Intermediate shaft 86 2nd Universal Joint 87 Pinion Shaft 88 Steering Gear 88a Pinion 88b Rack 89 Tie Rod 90 ECU
92 Deceleration device 93 Electric motor 94 Torque sensor 95 Vehicle speed sensor 98 Ignition switch 99 Power supply device 101 Cylindrical member

Claims (6)

An intermediate shaft with a dust cover that is placed through a through hole provided in the dash panel of a vehicle.
The intermediate shaft
A columnar shaft with a male groove on the outer circumference,
A cylindrical tube having a female groove on the inner circumference that fits into the male groove of the shaft portion,
It has an annular dust cover that is externally fitted to the tube and for closing the gap between the outer peripheral surface of the intermediate shaft and the inner peripheral surface of the through hole.
At one end of the tube in the axial direction,
A first protrusion that prevents the dust cover from coming out of the tube,
An intermediate shaft comprising a second protrusion that prevents the shaft portion from coming out of the tube. At least one of the first protrusions is integrally provided on a part of the outer diameter side of the tube, and at least one of the second protrusions is integrally provided on a part of the inner diameter side of the tube. The intermediate shaft according to claim 1, wherein the intermediate shaft is provided. The intermediate shaft according to claim 1 or 2, wherein the first protrusion and the second protrusion are integrally provided at the same position on one end of the tube in the axial direction. The intermediate shaft according to any one of claims 1 to 3, wherein the shaft portion and the tube are spline-fitted. The intermediate shaft according to any one of claims 1 to 3, wherein the shaft portion and the tube are serrated fitting. The intermediate shaft according to any one of claims 1 to 5, wherein a rolling element is interposed between the inner peripheral surface of the cylindrical portion of the tube and the outer peripheral surface of the cylindrical portion of the shaft portion.

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