JP2003285665A - Transfer shift actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the vibration resistance of a transfer shift actuator and make the actuator compact. <P>SOLUTION: The first step of a gear unit is composed of parallel shaft gears (1a, 2a), and worm gears (2b, 3a), which are small in size to enable large deceleration, are arranged at the second step to increase a reduction gear ratio of the gear unit to miniaturize a motor 1. The worm gears (2b, 3a) are arranged on the same side of the motor 1 against the parallel shaft gears (1a, 2a) to prevent the overhang of the motor 1. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a motor and a speed reduction mechanism that decelerates and outputs the output of the motor,
In particular, the present invention relates to an actuator suitable for use in switching between two-wheel drive and four-wheel drive for transfer of an automobile.

[0002]

2. Description of the Related Art As a conventional transfer shift actuator, for example, the one described in Japanese Patent Laid-Open No. 2000-71806 is known. The device described in this publication has a structure in which the rotation of the DC motor is reduced by the worm and the worm wheel and transmitted to the lever, and the rotation of the lever is transmitted to the rotating shaft via the spring and another lever. There is. Further, in this device, the rotation of the rotary shaft is converted into the axial movement of the shift fork shaft by the pinion and the rack of the shift fork shaft, and the shift fork moves from the position of 4WD (four-wheel drive) to the position of 2WD (two-wheel drive). Is configured to move to. When the DC motor is rotated in the reverse direction while the shift fork is located at the 2WD position, the shift fork moves from the 2WD position to the 4WD position. That is, in this apparatus, the output of the motor is decelerated by the worm gear, and the shift fork shaft inside the transfer case is reciprocated by the rack and pinion mechanism. In this device, a DC motor (motor) is mounted overhanging the transfer case.

[0003]

In the above-mentioned prior art, since a heavy motor is mounted over the housing (transfer case) so as to overhang, vibrations generated in each part as the vehicle runs and transmitted from the engine. There is a problem that it is necessary to increase the strength against vibration, and the external dimensions and weight increase. Again 1
Since the worm gear is used in the stage, it is necessary to generate a large torque in the motor, which causes a problem that the weight of the motor increases.

An object of the present invention is to provide a transfer shift actuator having high vibration resistance.

[0005]

In order to achieve the above object, in the present invention, the first stage of the gear device is a parallel shaft gear, and the second stage is a small worm gear capable of large reduction. The motor has been made smaller by increasing the reduction ratio. Further, by disposing the worm gear on the same side as the motor with respect to the parallel shaft gear, the motor is prevented from overhanging, whereby the vibration resistance can be improved. Further, in the present invention, it is preferable that the intermediate shaft is extended on the same side of the parallel shaft gear pair as the motor and between the motor and the output shaft, and a worm is formed on the extended shaft portion. It can be made compact. Further, in the present invention, it is preferable to dispose at least two mounting bolts between the intermediate shaft and the worm wheel, whereby a heavy motor can be firmly mounted to the transfer case and vibration resistance can be enhanced. . Further, in the present invention, it is preferable that the motor is built in the gear box so that the tail portion of the motor housing can be supported, whereby the vibration resistance can be further enhanced. Further, in the present invention, it is preferable to dispose the motor and the respective axes of the intermediate shafts in parallel to the mounting surface of the transfer case, whereby the motor can be mounted close to the transfer case, and a compact actuator can be obtained. . Further, if the gear that meshes with the worm in the final stage is a helical gear, the assembling property can be improved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

In FIG. 1, 1 is a motor, which is fixed to a gear box 4 by a bolt (not shown) on the output shaft side, and a motor pinion 1a is integrally attached to the output shaft. Reference numeral 2 denotes an intermediate shaft having a first-stage large gear 2a and a second-stage worm 2b. The worm 2b is formed integrally with the shaft, and the large gear 2a is press-fitted and fixed to the intermediate shaft 2. The intermediate shaft 2 is supported by a gear box 4 by a slide bearing 4a and a rolling bearing 4b so as to be rotatable only. Warm 2b
A worm wheel 3a fixed to the output shaft 3 is engaged with the shaft 3, and the output shaft 3 is driven by this.

A rotation sensor 5 which rotates integrally with the worm wheel 3a is attached to the worm wheel 3a so that the rotation angle of the output shaft can be detected.

When a mode selection switch (not shown) is turned on, the motor 1 is energized and starts rotating. When the transfer is rotated to the shift position in the selected mode, the electric current to the motor is cut off by the signal of the sensor 5, and the shift is completed. The operation of the signal of this sensor and the like is the same as that of the conventional technique, and therefore its explanation is omitted.

According to this embodiment, the first stage of the gear device is a parallel shaft gear (1a, 2a), and the second stage is a small worm gear (2b, 3a) capable of large deceleration and arranged for deceleration. The motor 1 can be downsized by increasing the ratio. Also,
The worm gears (2b, 3a) are arranged on the same side as the motor 1 with respect to the parallel shaft gears (1a, 2a) to prevent the motor 1 from overhanging. Can be increased.

Further, in this embodiment, the intermediate shaft 2 is extended on the same side as the motor 1 with respect to the parallel shaft gear pair (1a, 2a) and between the motor 1 and the output shaft 3, and the extension is performed. The worm 2b was formed on the shaft 3 portion. As a result, the device can be made compact.

The gear box 4 is provided with three bolt holes 4c for attaching to the transfer case 6. Two bolt holes 4c are arranged between the intermediate shaft 2 and the worm wheel 3a (on the intermediate shaft 2 side of the output shaft 3), and two mounting bolts are provided between the intermediate shaft 2 and the worm wheel 3a. I was able to fix it. This makes it possible to more strongly support the heavy motor 1.

The motor 1 is built in the gear box 4, and the tail portion of the motor in the gear box is supported by the bracket 4d. Thereby, the vibration resistance can be further enhanced.

FIG. 2 shows a front sectional view of this embodiment. The motor 1 and the respective axes of the intermediate shaft 2 are arranged parallel to the mounting surface of the transfer case 6. As a result, the transfer case 6 can be mounted close to the transfer case 6, so that the dimension in the height direction from the transfer case 6 can be reduced, and the actuator can be made compact.

FIG. 3 is a perspective view showing another embodiment. In this way, the gear that meshes with the worm 2b at the final stage, that is, the gear of the output shaft 3 is the helical gear 3b, so that the output shaft 3 can be meshed with the worm 2b in the lateral direction, so that the assemblability is improved. can do.

[0017]

According to the present invention, a parallel shaft gear is provided in the first stage as a reduction mechanism, a worm gear is provided in the second stage, and the worm gear is arranged on the same side as the motor with respect to the parallel shaft gear pair. Further, since the motor, the intermediate shaft, and the output shaft are arranged in this order, there is an effect that the vibration resistance strength of the transfer shift actuator can be increased and that the transfer shift actuator can be installed compactly. Furthermore, in the present invention, by disposing two or more bolts for attaching to the transfer case between the intermediate shaft and the worm wheel, the motor can be supported more firmly. Further, in the present invention, by incorporating the motor in the gear box and supporting the tail of the motor,
Vibration resistance can be further improved. Further, in the present invention, by disposing the motor and the intermediate shaft in parallel to the mounting surface of the transfer case, the mountability can be improved. Further, in the present invention, if the gear that meshes with the worm at the final stage is a helical gear, the assemblability can be improved.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a front sectional view of the embodiment of FIG.

FIG. 3 is a perspective view showing another embodiment.

[Explanation of symbols]

1 ... Motor, 1a ... Motor pinion, 2 ... Intermediate shaft, 2a ...
Large gear, 2b ... Worm, 3 ... Output shaft, 3a ... Worm wheel, 3b ... Helical gear, 4 ... Gear box, 4a ... Sliding bearing, 4b ... Rolling bearing, 4c ... Bolt hole, 4d ... Bracket, 5 ... Sensor, 6 ... Transfer case.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takehiko Owatari             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center (72) Inventor Hiroaki Saeki             Hitachinaka City, Ibaraki Prefecture 2520 Takaba             Ceremony Company Hitachi Ltd. Automotive equipment group (72) Inventor Mitsunobu Nishimura             Hitachinaka City, Ibaraki Prefecture 2520 Takaba             Ceremony Company Hitachi Ltd. Automotive equipment group F-term (reference) 3D036 GA11 GB05 GD02 GD09 GH01                       GH02 GH06 GJ17                 3D043 AA06 AA08 AB01 AB17 EB12                 3J009 EA06 EA11 EA12 EA19 EA25                       EA41 ED06 FA04

Claims (8)

[Claims] 1. A transfer shift actuator comprising a motor and a speed reducing mechanism for decelerating an output of the motor and transmitting the decelerated power to an output shaft provided in a direction traversing the shaft of the motor, the first stage of the speed reducing mechanism. Parallel shaft gears on
A transfer shift actuator, wherein a worm gear is provided in the second stage, and the worm gear is arranged on the same side as the motor with respect to the parallel shaft gear pair in the first stage. 2. The transfer shift actuator according to claim 1, wherein the parallel shaft gear pair includes a motor pinion provided on a shaft of the motor and a gear meshing with the motor pinion, and the gear meshing with the motor pinion. An intermediate shaft provided with is extended on the same side of the parallel shaft gear pair as the motor and between the motor and the output shaft, and a worm is formed on the extended shaft portion. Characteristic transfer shift actuator. 3. The transfer shift actuator according to claim 1, wherein a worm wheel meshing with the worm is provided on the output shaft, the shaft of the motor and the intermediate shaft are arranged in parallel, and the output shaft is the motor. The transfer shift actuator is arranged so as to be orthogonal to the axis of the vertical axis and the intermediate axis. 4. The transfer shift actuator according to claim 1, wherein a worm wheel that meshes with the worm is provided on the output shaft, and two gear boxes for mounting the worm and the worm wheel are attached to a transfer case. The transfer shift actuator, wherein the bolt is arranged on the side of the intermediate shaft with respect to the output shaft. 5. The transfer shift actuator according to claim 1, wherein the motor is built in an integrally formed gear box that houses the worm and the worm wheel. 6. The transfer shift actuator according to claim 1, wherein the motor is built in a gear box that houses the worm and the worm wheel, and a tail portion of the motor housing is supported by the gear box. Characteristic transfer shift actuator. 7. The transfer shift actuator according to claim 1, wherein the axes of the motor and the intermediate shaft are arranged in parallel with a mounting surface of a transfer case. 8. The transfer shift actuator according to claim 1, wherein the gear that meshes with the worm at the final stage is a helical gear.