WO2025108486A1

WO2025108486A1 - Holding mechanism for power door of vehicle

Info

Publication number: WO2025108486A1
Application number: PCT/CN2024/134275
Authority: WO
Inventors: Xun Sun; Yong Zhou; Fan Wang
Original assignee: Kiekert Automotive Changshu Co Ltd
Current assignee: Kiekert Automotive Changshu Co Ltd
Priority date: 2023-11-24
Filing date: 2024-11-25
Publication date: 2025-05-30
Anticipated expiration: 2026-05-24
Also published as: CN120042422A

Abstract

A holding mechanism for a power door of a vehicle, the holding mechanism comprising: a power unit; a transmission unit connected to the power unit; and a stop unit which can move under the action of the transmission unit so as to apply a braking force to the power transmission mechanism of the door drive assembly; characterized by further comprising an elastic piece arranged between the transmission unit and the stop unit to adjust the holding torque of the holding mechanism via the power unit. As can be seen from the above, the present invention proposes a holding mechanism for a door drive assembly, which enables adjustment of the holding torque applied to the door drive assembly by using an elastic piece, and can automatically adjust the holding torque according to different applications, thereby improving the safety and intelligence level of an electric door.

Description

HOLDING MECHANISM FOR POWER DOOR OF VEHICLE

Technical Field

The present invention relates to the technical field of vehicles, and in particular to a holding mechanism for a power door of a vehicle.

Background Art

A vehicle has multiple vehicle doors, such as a side door for a driver or a passenger to get on the vehicle and a tailgate for closing a trunk. Electric tailgates are first developed and have been widely used in vehicles because it is not convenient for users to open the tailgates by hand when holding things. With the further development of the vehicle's intelligence, electric methods are also gradually being used to open or close the side doors of vehicles. A known solution is that a motor is used to drive a worm, which drives a worm gear to rotate, and by means of a lead screw and nut mechanism, the worm gear then converts rotational movement of the motor into reciprocating movement of the lead screw and nut mechanism. When receiving a signal, the motor rotates, so as to open or close the vehicle door.

An electric side door faces such a problem that when the vehicle door is opened, if there is an external force, the vehicle door swings under the action of the external force, which in turn drives the motor to rotate in the reverse direction by means of a transmission mechanism. This movement of the vehicle door is obviously undesirable, which not only affects the user experience, but also poses potential risks. For example, the vehicle door will move in the door closing direction due to the external force, posing a risk of trapping the user.

To this end, a solution has been proposed in the prior art to provide a brake unit for holding the electric side door. For example, Chinese patent application CN 111386379 A discloses a power drive module for a vehicle door, the power drive module comprising an actuating assembly. A brake assembly cooperates with a part of the power drive module to prevent any rotational movement of the power drive module. This effectively holds the vehicle door in an open position or in a partially open position. A controller communicates with a motor and the brake assembly to coordinate operation during manual and/or automatic movement of the door. In this way, the vehicle door can be held in any open position on a certain slope or under a certain wind force. The brake assembly has a brake band which can be cooperated with a brake ring to prevent undesired rotation of a gearbox.

In addition, Chinese patent application CN 115961852 A also discloses a brake unit for an electric side door, the brake unit comprising a friction member, a spring and an adjusting member. The friction member is in frictional contact with a transmission shaft, the spring applies an elastic force to push the friction member toward the transmission shaft, and the adjusting member is used to adjust tension of the spring.

With the vigorous development and broad application prospects of electric door drive devices, it is necessary to develop other forms of door holding mechanisms. In addition, the above-mentioned friction braking method also suffers from some drawbacks, for example, its holding function may decay over time, resulting in a decrease in the performance of the holding function; and friction braking will produce noise, which is uncomfortable and may cause the user to think that there is a problem with the vehicle.

Summary of the Invention

An objective of the present invention is to solve at least one of the above problems and/or other problems in the prior art.

To achieve the above objective, the present invention provides a holding mechanism for a power door of a vehicle driven by a door drive assembly having a power transmission mechanism, the holding mechanism comprising:

a power unit;

a transmission unit connected to the power unit; and

a stop unit which can move under the action of the transmission unit so as to apply a braking force to the power transmission mechanism of the door drive assembly;

characterized by further comprising:

an elastic piece arranged between the transmission unit and the stop unit to adjust the holding torque of the holding mechanism via the power unit.

According to an aspect of the present invention, the stop unit is provided with:

a bearing part having a first bearing structure;

a stop part connected to the first bearing structure of the bearing part; and

a stop part connecting part, operatively connected to the stop part, and having a second bearing structure abutting against the elastic piece.

According to an aspect of the present invention, the stop part comprises a sector gear and a pinion which can rotate synchronously with the sector gear, wherein two sides of the pinion are respectively provided with a first rack and a second rack, and the first rack and the second rack abut against a part of the stop part connecting part at the same side.

According to an aspect of the present invention, the transmission unit comprises:

a worm connected to the power unit;

a first gear engaged with the worm;

an intermediate member coaxially arranged with the first gear and rotated synchronously therewith; and

a stop unit connecting part connected to the intermediate member and the stop unit.

According to an aspect of the present invention, the intermediate member is a second gear, and stop unit connecting part is provided with a rack portion meshed with the second gear.

According to an aspect of the present invention, the bearing part further has a cylindrical part, and the elastic piece is accommodated in the cylindrical part.

According to an aspect of the present invention, the stop unit connecting part is provided with a blocking part, and the cylindrical part of the bearing part of the stop unit is provided with a protruding part cooperated with the blocking part.

According to an aspect of the present invention, a detection device for detecting the deformation amount of the elastic piece is further comprised.

According to an aspect of the present invention, the detection device is a Hall sensor.

The present invention also proposes a method for operating the holding mechanism, comprising the following steps:

the power unit does not work when the vehicle door is closed;

the power unit does not work when the vehicle door is open and the vehicle is on the flat ground or the wind force is less than a first value;

the power unit works and the elastic piece provides a first force when the vehicle door is open and the vehicle is on a slope with an angle less than a first angle or the wind force is greater than the first value but less than a second value; and

the power unit works and the elastic piece provides a second force when the vehicle door is open and the angel of the slope is greater than the first angle but less than a second angle or the wind force is greater than the second value,

the first force being smaller than the second force.

As can be seen from the above, the present invention proposes a holding mechanism for a door drive assembly, which enables adjustment of the holding torque applied to the door drive assembly by using an elastic piece, and can automatically adjust the holding torque according to different applications, thereby improving the safety and intelligence level of an electric door.

Brief Description of the Drawings

Features and advantages of the present invention will be clearly understood from the detailed description provided below with reference to the accompanying drawings. It should be understood that the following accompanying drawings are only schematic and not necessarily drawn to scale, and therefore cannot be regarded as limiting the present invention. In the figures:

FIG. 1 (a) shows a front view of a holding mechanism according to an exemplary embodiment of the present invention, with the holding mechanism in a first state.

FIG. 1 (b) shows a view of FIG. 1 (a) with some members removed to illustrate a spring.

FIG. 2 shows the holding mechanism of FIG. 1 in a second state.

FIG. 3 shows the holding mechanism of FIG. 1 in a third state.

FIG. 4 shows a view of a double rack mechanism of the holding mechanism of the present invention.

FIG. 5 shows another view of the double rack mechanism of the holding mechanism of the present invention.

FIG. 6 shows a perspective view of a stop unit connecting part of the holding mechanism of the present invention.

FIG. 7 shows a perspective view of a bearing part of the holding mechanism of the present invention.

FIG. 8 (a) shows a perspective view of a stop part connecting part of the holding mechanism of the present invention from one perspective.

FIG. 8 (b) shows a perspective view of the stop part connecting part of the holding mechanism of the present invention from another perspective.

Detailed Description of Embodiments

The embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present invention. However, it will be obvious to those skilled in the art that the present invention may be implemented without some of these specific details. In addition, it should be understood that the present invention is not limited to the particular embodiments described. Instead, it is contemplated that the present invention can be implemented by any combination of the features and elements described below, regardless of whether they relate to different embodiments. Thus, the following aspects, features, embodiments and advantages are merely illustrative and should not be considered as elements or limitations of the claims, unless otherwise explicitly recited in the claims.

The terms such as "first" and "second" are used below to describe elements in the present application, and these terms are only used to distinguish the individual elements and are not intended to limit the nature, order or number of these elements. The terms "including" and "having" are used to denote an open-ended inclusion and mean that there may be additional elements/components in addition to the listed elements/components.

FIG. 1 (a) shows a front view of a holding mechanism according to an exemplary embodiment of the present invention, with the holding mechanism in a first state. The holding mechanism of the present invention is particularly suitable for an electric side door of a vehicle. The electric side door is a vehicle door provided with a door drive assembly. The vehicle door is typically rotationally connected, via a hinge, to a vehicle body, for example, at a door frame, and the vehicle door is driven by the door drive assembly to change an opening angle to open or close. As one exemplary implementation, the door drive assembly comprises a drive motor M, a worm connected to an output end of the drive motor, a worm gear meshed with the worm, a lead screw which passes through the worm gear and can rotate synchronously with the worm gear, a slider which is in threaded connection with the lead screw, and a rotating arm which has one end rotationally connected to the slider and the other end connected to the vehicle door. The axial directions of the worm gear and the worm shaft are arranged perpendicular to each other to change the power output direction of the drive motor. The axial direction of the rotating arm is parallel to the direction of the lead screw when the vehicle door is closed. The worm drives the worm gear and therefore the lead screw to rotate, such that the slider can move in the axial direction of the lead screw, so as to drive the rotating arm to extend or retract, thus enabling the vehicle door to be opened or closed. Of course, the transmission mechanisms used in the door drive assembly can be varied. For example, a planetary gear device or a multi-stage fixed-shaft gear transmission mechanism may be used. The present invention is not intended to define the specific structure of the door drive assembly, but rather to propose a mechanism for limiting the movement of the door drive assembly so as to hold the position of the vehicle door.

In FIG. 1 (a) , the drive motor M is a power source of the door drive assembly, which generates power according to a control signal, to drive a transmission device to operate and thus the door to be opened or closed. However, when the vehicle door is opened, if there is an external force, the vehicle door swings under the action of the external force, which in turn drives the motor to rotate in the reverse direction by means of a transmission mechanism. This movement of the vehicle door is obviously undesirable, which not only affects the user experience, but also poses potential risks. For example, the vehicle door will move in the door closing direction by the external force such that the user is trapped.

To this end, the present invention proposes a holding mechanism comprising a motor 1 as a power unit. Power of the motor 1 is transmitted to a transmission unit 2, the transmission unit 2 drives a stop unit 3, the stop unit 3 is engaged with an engagement unit G provided on a power transmission path of the door drive assembly, and the engagement unit G is fixedly connected to a power transmission mechanism of the door drive assembly, so that the stop of the door drive assembly can be realized by the stop unit 3, thereby enabling the position of the vehicle door to be held.

Specifically, the transmission unit 2 comprises a worm 21, a first gear 22 meshed with the worm 21, a second gear 23 which can rotate at the same angular speed as the first gear 22, and a stop unit connecting part 24 which moves in cooperation with the second gear 23. The stop unit connecting part 24 has a rack portion which cooperates with the second gear 23, so that when the second gear 23 rotates, the stop unit connecting part 24 can perform a linear movement. Moreover, the stop unit connecting part 24 has a portion which can be engaged with the stop unit 3, for driving the stop unit 3 to move.

The first gear 22 may be in the form of a worm gear. Preferably, to reduce noise, the first gear 22 is preferably in the form of a helical gear.

For this purpose, the stop unit 3 has a bearing part 31 and a stop part 32. The bearing part 31 is connected to the stop unit connecting part 24, and is provided with a first bearing structure 312 for bearing the stop part 32. For example, the bearing part 31 may be fixedly connected directly to the stop unit connecting part 24, whereby when the stop unit connecting part 24 moves, the bearing part 31 is moved accordingly, and moves the stop part 32 located thereon.

A preferred implementation of the stop part 32 is in the form of a sector gear, and the engagement unit G is correspondingly in the form of a gear, whereby the two can be engaged with each other by means of tooth engagement. The stop unit 3 may be engaged with the engagement unit G by means of the stop unit connecting part 24. When the stop part 32 is engaged with the engagement unit G, resistance can be provided to the engagement unit G and thus to the transmission mechanism of the door drive assembly, thereby preventing the vehicle door from swinging.

In FIG. 1, the motor 1 of the holding mechanism does not rotate, so that the stop unit 3 is not engaged with the engagement unit G. In this case, the holding mechanism is in the first state, i. e. in a non-working state. The first state is applicable to a state where the vehicle door is completely closed, or to a state where the vehicle door is open but the vehicle is on the flat ground and the wind force is less than a certain level, in which case the holding of the vehicle door can be achieved by short-circuiting the drive motor G. For this purpose, a slope sensor, a wind speed sensor, etc. on the vehicle may be used to detect the slope of the vehicle or the wind speed near the vehicle door.

FIG. 2 shows the holding mechanism of FIG. 1 in a second state. In the state shown in FIG. 2, the motor 1 is rotated by an angle, to drive the worm to rotate, and thus the first gear 22 to rotate, whereby the stop unit connecting part 24 drives the stop unit 3 to move downwardly, so that the stop part 32 is engaged with the engagement unit G to stop the door drive assembly and thus hold the vehicle door.

As a preferred implementation of the present invention, a holding torque adjustment function is also provided. The holding torque adjustment function is described further below with reference to FIGS. 6-8 (b) , based on the embodiment shown in FIG. 1 (a) . FIG. 6 shows a perspective view of a stop unit connecting part of the holding mechanism of the present invention. FIG. 7 shows a perspective view of a bearing part of the holding mechanism of the present invention. FIG. 8 (a) shows a perspective view of a stop part connecting part of the holding mechanism of the present invention from one perspective. FIG. 8 (b) shows a perspective view of the stop part connecting part of the holding mechanism of the present invention from another perspective.

As can be seen with reference to FIGS. 1 (a) , 1 (b) and 6, the stop unit connecting part 24 has a plate-like body extending linearly. The rack portion 243 is located at one end of the body, and an elastic piece abutment portion 241 is located at the other end of the body for abutment with one end of an elastic piece 25.

Referring to FIG. 7, the bearing part 31 has a cylindrical part 314 for accommodating the elastic piece 25. In addition, since the stop unit connecting part 24 compresses a spring when it moves downwardly, in order to prevent the stop unit connecting part 24 from colliding and interfering with the cylindrical part 314, an opening portion 313 is also provided on the cylindrical part 314. The bearing part 31 is further provided with a first bearing structure 312 fixedly connected to the cylindrical part 314 for mounting the stop part 32 and the stop part connecting part 33.

As shown in FIGS. 1 (a) , 8 (a) and 8 (b) , the stop unit 3 comprises the stop part connecting part 33. The stop part connecting part 33 is provided with a device for connecting to the stop part 32, the specific structure of which will be described in detail below with reference to FIGS. 4 and 5. The stop part connecting part 33 is provided with a second bearing structure 334 for bearing the elastic piece 25. That is, two ends of the elastic piece 25 abut between the elastic piece abutment portion 241 and the second bearing structure 334 of the stop part connecting part 33. The elastic piece 25 is in a slightly compressed state in this case. Specifically, the second bearing structure 334 may comprise a circular base 3342 to bear the elastic piece 25, and comprise a columnar portion 3341 to position the elastic piece 25.

In addition, the stop part connecting part 33 further comprises a main body portion 333, and the second bearing structure 334 is provided on one side of the main body portion 333. The main body portion 333 is provided with a transverse extension 3331 for abutment with the first bearing structure 312 and two racks to be described below. Perpendicular to the transverse extension 3331, a longitudinal extension 3332 is provided for guiding and limiting the two racks to be described below.

It can be seen therefrom that, in FIG. 1 (b) , when the racks are moved downwardly, the elastic piece is compressed, and the elastic piece presses the stop part connecting part 33 downwardly and thus presses the bearing part 31. The bearing part 31 drives the stop part 32 to move downwardly to engage with the engagement unit G.

As a preferred implementation, a blocking part 242 is further provided on the body of the stop unit connecting part 24 to limit the movement of the bearing part 31. For this purpose, the bearing part 31 is provided with a protruding part 311 for abutment with the blocking part 242 on the stop unit connecting part 24. A groove 244 may be further provided in the body of the stop unit connecting part 24 for movement of the protruding part 311 therein. In the first state, the elastic piece 25 is compressed to a certain extent, so that the elastic piece abutment portion 241 and the stop part connecting part 33 tend to move away from each other, and the blocking part 242 and the protruding part 311 abut against each other due to the elastic force of the elastic piece 25.

In the second state shown in FIG. 2, the degree of compression of the elastic piece 25 is substantially the same as that in the first state.

FIG. 3 shows the holding mechanism of FIG. 1 in a third state. As mentioned before, thanks to the provision of the holding torque adjustment function, different degrees of holding can be achieved by applying different forces to the elastic piece 25. Specifically, in the second state shown in FIG. 2, the degree of compression of the elastic piece 25 is relatively low, in which case the holding torque applied by the holding mechanism to the engagement unit G is at a relatively low degree. In the third state shown in FIG. 3, the degree of compression of the elastic piece 25 is relatively high, and the holding torque applied by the holding mechanism to the engagement unit G is at a relatively high degree.

Further, the holding mechanism is further provided with a double rack structure. Referring to FIGS. 4 and 5, the stop part 32 comprises, in addition to the sector gear 321, a pinion 322 which is coaxially disposed with the sector gear 321 and which can rotate synchronously with the sector gear. Two sides of the pinion 322 are respectively provided with a first rack 331 and a second rack 332. The first rack 331 and the second rack 332 are both meshed with the pinion 322.

In a stop state, the sector gear 321 is engaged with the engagement unit G. When the vehicle door is in a certain open position, if an undesired external force is applied, such as wind force, gravity component along a slope, etc., the vehicle door reversely transmits the received external force through the transmission mechanism of the door drive assembly, which is then transmitted to the sector gear 321 through the engagement unit G. The sector gear 321 is fixedly connected to the pinion 322, so that the external force can be further transmitted to the pinion 322. When the pinion 322 tends to rotate under the action of the external force, the pinion further transmits the external force to the first rack 331 and the second rack 332. Since the first rack 331 and the second rack 332 are located on the two sides of the pinion 322, the first rack 331 and the second rack 332 will move in opposite directions when the pinion 322 rotates.

Referring to FIGS. 4 and 5, the first rack 331 and the second rack 332 abut against a part of the stop part connecting part 33 at the same side. In this way, regardless of the undesired external force that is applied to open or close the vehicle door, when the external force is transmitted to the sector gear 321, a rack always applies a force to a part of the stop part connecting part 33, thereby transmitting this force to the elastic piece 25.

In this way, the holding torque of the holding mechanism can be adjusted by adjusting the degree of compression of the elastic piece 25. In FIG. 2, the degree of compression of the elastic piece 25 is less than the degree of compression in FIG. 3, whereby the holding torque in FIG. 2 is less than the holding torque in FIG. 3. By adjusting the torque, it is possible to have different holding torques in different states, ultimately resulting in a relatively low force required for manual operation, without significant impediment to manual operation by a user, providing a good operating feel. If the torque cannot be adjusted, it is necessary to set the torque to a large value, and the force required when manual operation is required will be large although it may meet the requirements for holding in all conditions. Furthermore, when the force used by the user to move the vehicle door exceeds a certain limit, the continuous rotation of the engagement unit G causes the engagement and rotation of the engagement unit G with the sector gear 321 to reach a limit, such that the two are disengaged from each other. Since the sector gear 321 is continuously subjected to a restoring force, the outermost teeth of the sector gear 321 continuously strike the engagement unit G, so that a force feedback for manual operation can be created.

Although the above description has been made on the basis of the example of the elastic piece 25 using compression elasticity, it is also conceivable that the elastic piece 25 may take other forms. For example, the elastic piece 25 may be in the form of a tension spring, and only the positions and structures of the components connected to two ends thereof need to be adaptively modified accordingly.

The holding mechanism is further provided with a detection device for detecting the deformation amount of the elastic piece 25. As an example implementation, a Hall sensor may be used as the detection device. In this way, the detected deformation amount of the elastic piece 25 can be transmitted to a control unit.

In actual operation, the holding mechanism of the present invention can work in the following states:

the power unit does not work when the vehicle door is closed;

the power unit works and the elastic piece provides a first force when the vehicle door is open and the vehicle is on a slope with an angle less than a first angle or the wind force is greater than a first value but less than or equal to a second value; and

the first force being smaller than the second force.

In fact, it is also possible to store in advance multiple settings of holding force corresponding to the slope and the wind force in a storage device, without being limited to the above-mentioned settings, so that the holding mechanism always provides a holding force that is slightly larger than the holding force required for the corresponding slope and wind force, so as to achieve a better holding effect.

Therefore, the holding mechanism of the present invention can provide different holding torques for different applications, thereby better holding the vehicle door.

Various modifications and variations of the embodiments disclosed above may be made to those skilled in the art without departing from the scope or spirit of the present invention. Other embodiments of the present invention are apparent to those skilled in the art from the practice of the present invention disclosed in this description. This description and the examples disclosed therein are to be regarded as exemplary only, and the true scope of the present invention is specified by the appended claims and their equivalents.

Claims

A holding mechanism for a power door of a vehicle driven by a door drive assembly having a power transmission mechanism, comprising:

a power unit (1) ;

a transmission unit (2) connected to the power unit (1) ; and

a stop unit (3) which can move under the action of the transmission unit (2) so as to apply a braking force to the power transmission mechanism of the door drive assembly;

characterized by

an elastic piece (25) arranged between the transmission unit (2) and the stop unit (3) to adjust the holding torque of the holding mechanism via the power unit (1) .
The holding mechanism according to claim 1, characterized in that,

the stop unit (3) is provided with:

a bearing part (31) having a first bearing structure (312) ;

a stop part (32) connected to the first bearing structure of the bearing part; and

a stop part connecting part (33) , operatively connected to the stop part, and having a second bearing structure (334) abutting against the elastic piece.
The holding mechanism according to claim 2, characterized in that,

the stop part (32) comprises a sector gear (321) and a pinion (322) which can rotate synchronously with the sector gear, wherein two sides of the pinion are respectively provided with a first rack (331) and a second rack (332) , and the first rack and the second rack abut against a part of the stop part connecting part at the same side.
The holding mechanism according to claim 1, characterized in that,

the transmission unit (2) comprises:

a worm (21) connected to the power unit;

a first gear (22) engaged with the worm;

an intermediate member coaxially arranged with the first gear and rotated synchronously therewith; and

a stop unit connecting part (24) connected to the intermediate member and the stop unit (3) .
The holding mechanism according to claim 4, characterized in that,

the intermediate member is a second gear (23) , and stop unit connecting part (24) is provided with a rack portion meshed with the second gear (23) .
The holding mechanism according to claim 2, characterized in that,

the bearing part (31) further has a cylindrical part (314) , and the elastic piece (25) is accommodated in the cylindrical part (314) .
The holding mechanism according to claim 4, characterized in that,

the stop unit connecting part (24) is provided with a blocking part (242) , and the cylindrical part (314) of the bearing part (31) of the stop unit (3) is provided with a protruding part (311) cooperated with the blocking part (242) .
The holding mechanism according to claim 1, characterized by

a detection device for detecting the deformation amount of the elastic piece (25) .
The holding mechanism according to claim 8, characterized in that,

the detection device is a Hall sensor.
A method for operating the holding mechanism according to any of claims 1 to 9, comprising the following steps:

the power unit does not work when the vehicle door is closed;

the power unit does not work when the vehicle door is open and the vehicle is on the flat ground or the wind force is less than a first value;

the power unit works and the elastic piece provides a first force when the vehicle door is open and the vehicle is on a slope with an angle less than a first angle or the wind force is greater than the first value but less than or equal to a second value; and

the power unit works and the elastic piece provides a second force when the vehicle door is open and the angel of the slope is greater than the first angle but less than a second angle or the wind force is greater than the second value,

the first force being smaller than the second force.