ELECTRIC BRAKE HAVING PARKING SWITCH MODULE

An electric brake of a caliper type according to an embodiment may include: a caliper device including a caliper body and a pair of brake pads installed in the caliper body; a driver including a housing forming a space therein, an electric motor configured to generate a driving force, and a transfer device configured to move the pair of brake pads with a driving force; and a parking switch module configured to limit an operation of the transfer device.

CROSS-REFERENCE TO RELATED APPLICATION(S)

BACKGROUND

The disclosure relates to an electric brake having a parking switch module.

2. Description of the Related Art

A brake system is an apparatus that decelerates and stops a vehicle in motion and maintains the vehicle in a stopped state. The brake system includes a parking brake that decelerates and stops a vehicle in motion and maintains the vehicle in a stopped state.

The parking brake maintains the stopped state of the wheels by pulling the parking cable by the control of a lever located to one side of the driver seat inside the vehicle to provide a braking force to the wheels connected to the parking cable, and removes the braking force provided to the wheels by releasing the lever to release the parking cable.

Because the parking brake operates only by a driver's intention, the driver should control the lever whenever parking or starting driving, which has caused the driver's great inconvenience in use. For this reason, an Electric Parking Brake (EPB) system for automatically operating the parking brake by the motor according to the operation state of the vehicle has been developed.

Brake systems are classified into a positive brake system and a negative brake system. The positive brake system is a brake system that causes a contact of the brake disc by supplying pressure to the brake disc ordinarily being in a non-contact state in order to stop the vehicle or reduce the speed of the vehicle. In contrast, the negative brake system is a brake system that separates the brake disc by supplying pressure to the brake disc ordinarily being in a contact state in order to move the vehicle.

The negative brake system operates the brake by releasing pressure through a driver's control in a normal state. However, in emergency situations, such as a situation in which the vehicle stalls during driving, a situation in which the engine stops abnormally, a situation in which a problem occurs in the electrical system, a situation in which a problem occurs in the hydraulic or pneumatic system, etc., the negative brake system applies a braking force by the parking brake by automatically releasing pressure supplied to the parking brake.

SUMMARY

It is an embodiment of the disclosure to provide a caliper type electric brake having a parking switch module

It is an embodiment of the disclosure to provide a drum type electric brake having a parking switch module.

In accordance with an aspect of the disclosure, an electric brake of a caliper type may include: a caliper device including a caliper body and a pair of brake pads installed in the caliper body: a driver including a housing forming a space therein, an electric motor configured to generate a driving force, and a transfer device configured to move the pair of brake pads with a driving force; and a parking switch module configured to limit an operation of the transfer device.

The transfer device may include: an input gear coupled to a rotating shaft of the electric motor; a transfer gear spaced from the input gear; a power transfer belt configured to interlock a rotation of the input gear with the transfer gear; and an outputter configured to move the pair of brake pads by receiving a driving force from the transfer gear.

The transfer gear may include: a cylindrical portion including an outer circumference on which a pinion gear is formed; and a flange portion including an edge in which a latch groove is formed at regular intervals.

The parking switch module may include: a pawl pin installed in the housing;

a pawl rotatably coupled to the pawl pin; a driving pin configured to rotate the pawl by pushing one end of the pawl; and a driving valve configured to move the driving pin.

The parking switch module may further include a unlock pin configured to rotate the pawl by pushing another end of the pawl.

A rear end of the unlock pin may be configured to be exposed to outside of the housing by penetrating the housing.

The parking switch module may further include a torsion spring positioned between the pawl and the pawl pin and configured to provide a restoring force to the pawl.

The parking switch module may further include a spring installed on a top end of the unlock pin.

One end of the pawl may be configured to be coupled to the latch groove according to a movement of the driving pin by the driving valve after the transfer gear rotates in a forward direction.

While one end of the pawl does not depart from the latch groove upon a parking release, the one end of the pawl may be configured to rotate by the unlock pin pushing another end of the pawl and depart from the latch groove.

According to an aspect of the disclosure, an electric brake of a drum type may include: a drum brake portion installed in a wheel of a vehicle; a driver including a housing forming a space therein, an electric motor configured to generate a driving force, and a gear set configured to rotate by a driving force; and a parking switch module accommodated inside the driver and configured to limit a rotation of the gear set.

The gear set may include: an input gear coupled to a rotating shaft of the electric motor; and a transfer gear configured to rotate by receiving a driving force from the input gear.

A pinion gear may be formed on an outer circumference of the transfer gear, and a latch groove may be formed at regular intervals in a front surface of the transfer gear along an edge of the front surface.

The parking switch module may include: a pawl pin installed in the housing; a pawl rotatably coupled to the pawl pin; a driving pin configured to rotate the pawl by pushing one end of the pawl; and a driving valve configured to move the driving pin.

The parking switch module may further include an unlock pin configured to rotate the pawl by pushing another end of the pawl.

The parking switch module may further include a torsion spring positioned between the pawl and the pawl pin and configured to provide a restoring force to the pawl.

The electric motor may be accommodated in a motor housing protruding from one side of the housing, and the driving valve may be accommodated in a valve housing protruding from another side of the housing.

The driver may further include a driving shaft extending to inside of the drum brake portion, and the driving shaft may be positioned coaxially with the transfer gear by penetrating a center of the transfer gear, and configured to interlock with a rotation of the transfer gear.

In a parking mode, one end of the pawl may be coupled to the latch groove by rotating by the driving pin after the transfer gear rotates in the forward direction.

While one end of the pawl does not depart from the latch groove upon a parking release, the one end of the pawl may be configured to rotate by the unlock pin and depart from the latch groove, and then, the transfer gear may be configured to rotate in a backward direction.

DETAILED DESCRIPTION

Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings. The following embodiments are provided to transfer the concepts of the disclosure to one of ordinary skill in the technical art to which the disclosure belongs. However, the disclosure is not limited to these embodiments, and may be embodied in another form. In the drawings, parts that are irrelevant to the descriptions may be not shown in order to clarify the disclosure, and also, for easy understanding, the widths, lengths, thicknesses, etc. of components may be more or less exaggeratedly shown. Like reference numerals refer to like components throughout the specification.

FIG.1is a perspective view for describing a caliper type electric brake (Caliper EMB)1according to an embodiment of the disclosure.FIG.2is an enlarged perspective view of an area indicated by A inFIG.1.FIG.3is a view for describing an operation of a parking switch module100of the electronic brake1shown inFIG.1in a parking mode.FIG.4is a view for describing conversion from the parking mode to a release mode inFIG.3.

Referring toFIGS.1to4, the caliper type electric brake1will be described. The caliper type electric brake1may be an electromechanical brake installed on a brake disc, and correspond to a normal brake operating with electricity, not a parking brake.

The caliper type electric brake1may include: a caliper device10including a caliper body11and a pair of brake pads12installed in the caliper body11; a driver20including a housing21forming a space therein, an electric motor22for generating a driving force, and a transfer device30for moving the brake pads12with a driving force; and a parking switch module100configured to limit an operation of the transfer device30.

As the market share of electric vehicles and autonomous vehicles increases, needs for development of EMB (electromechanical brake) which operates with electricity without hydraulic pressure have increased, and the EMB may provide normal braking and parking brake functions.

When a motor for releasing parking fails to be driven for an unknown cause after parking, the braking force may not be released and it may be impossible to tow the vehicle. In these cases, it may be difficult to bring the vehicle back to its normal state, and against this, a mechanical backup plan for releasing parking under the concept of fail safe is required.

The electric brake1may provide, as the parking switch module100, a parking brake force release apparatus capable of releasing, when electronic equipment of EMB fails, a parking brake force by a mechanical method from outside.

The transfer device30may include an input gear31coupled to a rotating shaft of the electric motor22, a transfer gear40spaced from the input gear31, a power transfer belt32for interlocking a rotation of the input gear31with the transfer gear40, and an outputter50configured to move the brake pads12by receiving a driving force from the transfer gear40.

The outputter50may include an output gear51that rotates by engaging with the transfer gear40, and a pressing shaft52configured to push the brake pads12by moving by a rotation of the output gear51. The output gear51may rotate by engaging with a shaft gear46that rotates by interlocking with the transfer gear40.

The transfer gear40may include a cylindrical portion41having an outer circumference on which a pinion gear44is formed, and a flange portion42having an edge in which a latch groove43is formed at regular intervals. The latch groove43may be a rachet allowing a rotation only in one direction, wherein one side of the latch groove43may have a gentle slope and another side of the latch groove43may be in a shape of a projection.

The parking switch module100may include a pawl pin110installed in the housing21, a pawl120rotatably coupled to the pawl pin110, a driving pin130configured to rotate the pawl120by pushing one end of the pawl120, and a driving valve140configured to move the driving pin130. The pawl pin110may function as a rotating axis of the pawl120.

The driving pin130may be coupled to and integrated into the driving valve140to move forward or backward from the driving valve140. The driving valve140may be, for example, a solenoid valve.

The parking switch module100may further include a torsion spring160positioned between the pawl120and the pawl pin110to provide a restoring force to the pawl120. Accordingly, in a non-parking state, that is, in a state in which the driving pin130does not push one end of the pawl120, one end of the pawl120may not be inserted into the latch groove43.

The parking switch module100may further include a unlock pin150configured to rotate the pawl120by pushing another end of the pawl120. The unlock pin150may rotate the pawl120in an opposite direction of a direction in which the driving pin130rotates the pawl120. A rear end of the unlock pin150may penetrate the housing21and be exposed to outside of the housing21. Because a portion of the unlock pin150is exposed to the outside of the housing21, it may be easy to operate the unlock pin150upon occurrence of a failure.

The parking switch module100may further include a spring170installed on a top end of the unlock pin150. The spring170may be a compression spring, such as a coil spring, a wave spring, and the like.

An operating mechanism (upon application) of the parking switch module100will be described below. One end of the pawl120may be coupled to the latch groove43when the driving valve140moves the driving pin130after the transfer gear40rotates in a forward direction.

More specifically, upon turning-on of the electric motor22, the transfer gear40may rotate in the forward direction to generate a parking brake force. In contrast, upon turning-off of the electric motor22, the transfer gear40may rotate in the backward direction to release the parking brake force. Upon turning-on of the driving valve140, the driving pin130may move forward, and accordingly, the pawl120may rotate to be coupled to the latch groove43. Upon turning-off of the driving valve140, the driving pin130may move backward, and due to the coupling of the pawl120to the latch groove43, the transfer gear40may be prevented from rotating in the backward direction, thereby maintaining the parking brake force.

An operating mechanism (upon release) of the parking switch module100will be described below. By turning on the electric motor22, the transfer gear40may rotate by a preset distance in the forward direction. Accordingly, the pawl120may be decoupled from the latch groove43and rotate to an original position by the restoring force of the torsion spring160. Then, the transfer gear40may rotate in the backward direction to release the parking brake force.

When one end of the pawl120does not depart from the latch groove43while parking is released, the pawl120may rotate by the unlock pin150pushing the other end of the pawl120, and thereby, the one end of the pawl120may depart from the latch groove43. That is, when parking is not released for a cause, such as a failure of the electric motor22, a failure of the torsion spring160, etc., parking may be released by operating the unlock pin150outside the housing21.

The unlock pin150may correspond to fail safe for releasing a parking brake force by a mechanical method upon a failure of electronic equipment. The unlock pin150may be controllable from the outside and decouple the pawl120from the latch groove (Ratchet)43by pressing the pawl120to rotate the pawl120, and the torsion spring160may be compressed by an external force upon operation while fixing the unlock pin150to an original position.

When the unlock pin150is pressed from the outside of the housing21, the unlock pin150may compress the torsion spring160and move toward the other end of the pawl120to press the other end of the pawl120. In this case, the pawl120may rotate on the pawl pin110as the rotating axis to release a contact with the latch groove43, thereby releasing the parking brake force.

FIG.5is a perspective view for describing an operation state of a drum type electric brake2according to an embodiment of the disclosure.FIG.6is a front view of the electric brake2shown inFIG.5.FIG.7is a rear view of the electric brake2shown inFIG.5.FIG.8is a view for describing a driving shaft65of the electric brake2shown inFIG.5. Descriptions about the same content as that described in the above embodiments will be omitted.

The drum type electric brake (Drum EMB)2, which is an electromechanical brake installed in a drum, may be used commonly as a parking brake and operate with electricity.

The drum type electronic brake2may include: a drum brake portion80installed in a wheel of a vehicle; a driver60including a housing61forming a space therein, an electric motor62for generating a driving force, and a gear set70that rotates by a driving force; and a parking switch module200accommodated inside the driver60and configured to limit a rotation of the gear set70.

The gear set70may include an input gear71coupled to a rotating shaft of the electric motor62, and a transfer gear72that rotates by receiving a driving force from the input gear71.

On an outer circumference of the transfer gear72, a pinion gear74may be formed, and in a front surface of the transfer gear72, a latch groove73may be formed at regular intervals along an edge of the front surface.

The parking switch module200may include a pawl pin210installed in the housing61, a pawl220rotatably coupled to the pawl pin210, a driving pin230configured to rotate the pawl220by pushing one end of the pawl220, and a driving valve240configured to move the driving pin230. The pawl pin210may function as a rotating axis of the pawl220.

The electric motor62may be accommodated in a motor housing611protruding from one side of the housing61, and the driving valve240may be accommodated in a valve housing612protruding from another side of the housing61.

The parking switch module200may further include a unlock pin250configured to rotate the pawl220by pushing another end of the pawl220.

The parking switch module200may further include a torsion spring260positioned between the pawl220and the pawl pin210to provide a restoring force to the pawl220.

The driver60may further include a driving shaft65extending to inside of the drum brake portion80, and the driving shaft65may be positioned coaxially with the transfer gear72by penetrating a center of the transfer gear72, and configured to interlock with a rotation of the transfer gear72.

In a parking mode, one end of the pawl220may be coupled to the latch groove73by rotating by the driving pin230after the transfer gear72rotates in the forward direction.

When the one end of the pawl220does not depart from the latch groove73while parking is released, the one end of the pawl220may rotate by the unlock pin250pushing another end of the pawl220and depart from the latch groove73, and then, the transfer gear72may rotate in the backward direction.

According to an embodiment, fail safe against a malfunction of the parking function of the electric brake may be provided.

The electric brake according to an embodiment may release a braking force by causing the unlock pin included in the parking switch module to rotate the pawl caught by the parking gear.

The electric brake according to an embodiment may control the pawl more accurately by providing two pins capable of pressing both sides of the pawl.

So far, although the disclosure has been described by the limited embodiments and drawings, the disclosure is not limited to these, and various corrections and modifications can be made by one of ordinary skill in the technical art to which the disclosure belongs within the technical concepts of the disclosure and equivalents of the appended claims.