The present invention relates to an automobile door-lock drive device housing within a case a worm gear provided on an output shaft of an electric motor and a wheel gear engaging with this worm gear and performing a switching operation of a lock mechanism using a torque of this wheel gear.
Conventionally, automobile door-lock drive devices have been as specified in patent document 1. In this patent document 1, a worm-gear type drive gear driven by a motor (electric motor) is engaged with a reduction gear in the form of a wheel gear, a torque from this reduction gear is further engaged with a sector gear, and a torque of this sector gear is transmitted to an output gear.
In devices provided with a reducing mechanism transmitting a torque of an electric motor from a worm gear to a wheel gear such as specified in patent document 1, an output shaft of the electric motor and the worm gear are often fixed by connection.
To give one such example, as shown in
To explain in more detail, freely transmitting torque is made possible by, for example, D-cutting the output shaft 02 or forming a spline fitting section on the output shaft 02 and forming the fitting hole 011C of the worm gear 011 so as to have a shape corresponding thereto. For example, this output shaft 02 is fixed by driving into the worm gear 011, or the output shaft 02 and the worm gear 011 are each completely fixed using a pin, etc. passing through both thereof. Many configurations reliably transmitting a torque of the output shaft 02 to the worm gear 011 in this way have been used.
Furthermore, in configurations wherein the output shaft 02 and the worm gear 011 are fixed by connection in this way, the relative positioning of the worm gear 011 and the wheel gear 012 must be properly maintained. For this reason, configurations wherein, as shown in the same figure, an end section 04 of the electric motor 01 at a side opposite to that of the worm gear 011 and an end section of a shaft section 011A of the worm gear 011 at a side opposite to that of the electric motor 01 are supported so as to come into contact with a case 020 are also used.
In this type of automobile door-lock drive device, locking is carried out and locking is released using an operation of the electric motor. However, when this operation of the electric motor has been stopped, a dynamic inertial force of the wheel gear acts powerfully on the worm gear in a direction of thrust immediately after this stopping. For this reason, the electric motor connected to the worm gear makes powerful contact with the case, and in some cases, an impact sound has been transmitted to a door.
A cushioning member may be used in order to curb this impact sound. However, when rubber-type material is used in the support system for the motor and worm gear, the number of parts increases and cost rises. Furthermore, it becomes impossible to maintain a high degree of accuracy of the relative positions of the worm gear and the wheel gear, and practical usage is difficult.
The object of the present invention is to provide a reasonable configuration of a device capable of reducing the impact sound generated upon stopping of the electric motor while maintaining high relative positioning of the worm gear and the wheel gear.
The characteristic feature of the present invention is that, in an automobile door-lock drive device housing a worm gear provided on an output shaft of an electric motor and a wheel gear engaging with this worm gear in a case and performing a switching operation of a lock mechanism using a torque of this wheel gear, a support member making contact while interposed between the worm gear and the electric motor is provided, a transmission section including the output shaft of the electric motor and the worm gear pivotally supported on the output shaft is provided, and the transmission section allows relative motion of the output shaft and the worm gear.
When the electric motor stops and a force resulting from dynamic inertia of the wheel gear acts on the worm gear in a direction of thrust, this configuration makes it possible for the support member to bear the force in the direction of thrust of the worm gear. Furthermore, this force in the direction of thrust is not transmitted to the output shaft. In addition, provision of a support member makes it possible for a position of the worm gear in a direction of an axis of the output shaft to be maintained. As a result, the relative positioning of the worm gear and the wheel gear can be maintained high. Furthermore, despite the fact that no cushioning member is used, a reasonable configuration of a device capable of reducing impact sound generated when the electric motor stops is realized.
In accordance with the present invention, the transmission section may be configured such that the output shaft is fitted into a fitting hole formed in the worm gear so as to be capable of freely transmitting torque and of freely moving relatively in a direction of an axis, and a tip of the output shaft and an inner end of the fitting hole may be separated in a direction of the axis.
As a result of this configuration, for example, a gap is formed by D-cutting the output shaft, forming the fitting hole of the worm gear with a shape fitting the D-cut, and separating a tip of the output shaft and an inner end of the fitting hole in a direction of the axis. When using a relatively-simple configuration of this kind, there is no need to use a complicated configuration and costs can be reduced.
In accordance with the present invention, the support member may include a two-pronged section forming a recess wherein the output shaft is inserted.
This configuration makes it possible for deflection of the output shaft in a radial direction to be reduced since the output shaft is inserted into the recess of the two-pronged section.
In accordance with the present invention, the support member may include a fitting section wherein an end section of the electric motor on the output-shaft side thereof is fitted and a receiving section receiving an end section of the worm gear on the electric-motor side thereof so as to be capable of rotating freely, formed as one with the two-pronged section.
This configuration makes it possible for a degree of accuracy of the relative positions of the electric motor and the worm gear to be increased since an end section of the electric motor is fitted into one of the fitting sections formed in the support section and the worm gear is supported so as to be capable of rotating freely by the receiving section formed in the support section.
In accordance with the present invention, a support member configured as a separate member to the case may be mounted on an inner section of the case.
For example, when the case is manufactured using a resin or metal mold, this configuration eliminates the need for a complicated configuration to be employed in order to integrally form the support member. Even changes of the specification of the electric motor or the worm gear can be supported simply by changing the configuration of the support member.
In accordance with the present invention, the support member may be formed inside the case as one with the case.
For example, when the case is manufactured using a resin or metal mold, this configuration makes it possible for only integral forming of the support member to be required.
In accordance with the present invention, a gear support section receiving an end section of the worm gear on a side opposite to that of the electric motor so as to be capable of rotating freely may be provided in the case, and a cushioning member making contact with the end section of the worm gear supported by this gear support section from a direction parallel to the axis may be provided in the gear support section.
This configuration makes it possible not only for the accuracy of support of this worm gear to be increased by supporting the worm gear in the support section, but even in cases where the worm gear moves in a direction of approach to the gear support section due to an action of a force from the wheel gear upon stopping of the electric motor, for this motion to be reduced and stopped by the cushioning member and the occurrence of impact sound to be curbed.
In accordance with the present invention, a cushioning member making contact with the end section of the worm gear supported by the receiving section from a direction parallel to the axis may be provided in this receiving section.
Even in cases where the worm gear moves in a direction of approach to the electric motor upon stopping of the electric motor, this configuration makes it possible for this motion to be reduced and stopped by the cushioning member and the occurrence of impact sound to be curbed.
In accordance with the present invention, a cushioning member may be provided between a tip of the output shaft and an inner end of the fitting hole.
Even in cases where the output shaft and the worm gear move in a direction so as to approach relatively due to an external force acting on the worm gear, this configuration makes it possible for this motion to be reduced and stopped by the cushioning member and the occurrence of impact to be curbed.
In accordance with the present invention, a bearing section may be formed as a protrusion on the electric motor at an end thereof opposite to that of the output shaft, a motor support section wherein this bearing section is supported by fitting may be provided in the case, and a cushioning member making contact with the bearing section supported by this motor support section from a direction parallel to the axis may be provided in this motor support section.
Even in cases where the electric motor moves so as to become separated from the worm gear, this configuration makes it possible for this motion to be reduced and stopped by the cushioning member and the occurrence of impact to be curbed.
The following is a description of the preferred embodiments of the present invention, with reference to the drawings.
Overall Configuration
As shown in
This door-lock drive device is provided inside the door of a vehicle such as an automobile, and operations switching the lock mechanism between a locked condition and an unlocked condition can be achieved through reduction of a torque of the electric motor 1 and transmission thereof to the operation shaft 16.
The electric motor 1 is provided with bearing sections 3, 4 at a front-end side and a rear-end side of the motor body as a bearing means for the output shaft 2 rotating as one with an internal rotor (not shown). This output shaft 2 passes through the bearing section 3 of the front-end side. A protrusion section of this output shaft 2 is formed by D-cut machining so as to have a D-shaped cross section.
The output shaft 2 and the worm gear 11 are disposed on the same axis X. This worm gear 11 includes a shaft section 11A and a gear section 11B formed at a central position in the direction of the axis X on this shaft section 11A. A fitting hole 11C wherein the output shaft 2 is fitted so as to be capable of freely transmitting torque is formed at one end-section side.
The output shaft 2 having been D-cut in this way and the fitting hole 11C form a transmission section wherein a torque of the output shaft 2 is transmitted to the worm gear 11, and in addition, the output shaft 2 and the worm gear 11 are capable of freely moving relatively in the direction of the axis X. Furthermore, with the electric motor 1 and the worm gear 11 supported by the case 20, as shown in
This transmission section may be configured by, for example, forming a spline section on an outer surface of the output shaft 2 and a structure fitting with the spline section in the fitting hole 11C, or by embedding a key in a channel formed parallel to a direction of an axis of the output shaft 2 and forming a channel into which this key enters in a hole section of the worm gear 11.
Support Structure
A motor support section 21 into which the bearing section 4 at the rear-end side of the electric motor 1 is fitted and a gear support section 22 into which the shaft section 11A of the worm gear 11 at an end thereof opposite to that of the electric motor is fitted are formed on an inner surface of the case 20. Furthermore, a support member 30 touching (making contact with) the shaft section 11A of the worm gear 11 at an end section thereof on the side of the electric motor is mounted on an inner surface of the case 20.
The support member 30 has a two-pronged member 31 including a recess 31A wherein the output shaft 2 is fitted, and a receiving section 32 supporting the shaft section 11A of the worm gear 11 so as to be capable of freely rotating and a fitting section 33 into which the bearing section 3 at the front-end side of the electric motor 1 (example of an end section at the output-shaft side of the electric motor 1) has been fitted, formed as one.
As shown in
In particular, the support member 30 may, upon formation of the case 20, be formed as one with the case 20 using the same material. By forming as one with the case 20 in this way, the strength of this supporting member 30 can be raised.
Function of Support Structure
As the electric motor 1 and the worm gear 11 are supported by the case 20 in this way, upon driving of the electric motor 1, the torque from the output shaft 2 is transmitted from the worm gear 11 to the wheel gear 12, and the pin 14 of this wheel gear 12 drives the arm 15 via the recess 15A. In this way, the lock mechanism can be locked and unlocked using the rotation of the arm 15. After operation of this electric motor 1, the dynamic inertia of the wheel gear 12 acts on the worm gear 11 in a direction of thrust when the electric motor 1 has been stopped. However, as force from the worm gear 11 is borne by the support member 30, the phenomenon of the electric motor 1 making powerful contact with the case 20 is prevented and impact sound is not generated.
In particular, by supporting an end section of the shaft section 11A of the worm gear 11 in the receiving section 32 formed in the support member 30 so as to be capable of rotating freely and supporting the bearing section 3 at the front-end side of the electric motor 1 in a fitting condition in the fitting section 33 formed in this support member 30, a high degree of accuracy of the relative positions of the worm gear 11 and the electric motor 1 can be maintained.
In addition to the above-explained embodiment, the present invention may be configured as follows.
(a) A configuration wherein an end section of the output shaft 2 has a member of a large diameter, a fitting hole is formed parallel to the direction of the axis X on this, and the worm gear 11 has a shaft-shaped member inserted into this fitting hole so as to be capable of freely transmitting torque may be provided as a transmission section transmitting torque from the output shaft 2 of the electric motor 1 to the worm gear 11.
(b) A mechanism assembling a simple gear and crank mechanism to a transmission system transmitting torque from the worm gear 11 to the operation shaft 16 may be used, or a non-circular gear may be used to convert rotation motion from the electric motor 1 into intermittent motion.
(c) As shown in
(d) As shown in
(e) As shown in
(f) As shown in
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2005/023959 | 12/27/2005 | WO | 00 | 6/18/2008 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2007/074527 | 7/5/2007 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5216929 | Ochiai et al. | Jun 1993 | A |
5564308 | Hoshikawa et al. | Oct 1996 | A |
Number | Date | Country |
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4-134946 | Dec 1992 | JP |
5-33541 | Feb 1993 | JP |
8-13881 | Jan 1996 | JP |
9-201003 | Jul 1997 | JP |
11-196552 | Jul 1999 | JP |
11210295 | Aug 1999 | JP |
2002-129789 | May 2002 | JP |
2002-171720 | Jun 2002 | JP |
Number | Date | Country | |
---|---|---|---|
20090031838 A1 | Feb 2009 | US |