KR20220158354A - Electric parking brake for electromotive forklift truc - Google Patents

Abstract

An electronic parking brake for an electric forklift is disclosed. According to one aspect of the present invention, the electronic parking brake for an electric forklift that is electronically operated to operate a parking lever provided on a front wheel, comprising: a brake module operating an operating cable by converting rotational force into linear motion to operate the parking lever; a power transmission part which is connected with a parking cable connected with the parking lever and the operating cable, respectively, and transmits a pulling force of the brake module to the parking cable; and an electronic control unit for controlling the brake module, thereby capable of realizing a parking braking force so that a large force is exerted with a small force.

Description

Electronic parking brake for electric forklift {ELECTRIC PARKING BRAKE FOR ELECTROMOTIVE FORKLIFT TRUC}

The present invention relates to an electronic parking brake for an electric forklift, and more particularly, to an electronic parking brake for an electric forklift that is operated electronically by a motor.

In general, forklifts are used to lift and lower heavy loads or transport them to a desired location within a limited space, and are largely divided into engine forklifts and electric forklifts according to power sources.

The electric forklift uses electricity from a battery as a power source, and a drive motor for driving the vehicle is provided on the front wheel, and is mainly used for indoor work because it has no exhaust gas and low noise compared to an engine forklift. The electric forklift is provided with a brake device to brake the wheels when stopping to load a load or when parking. This brake device is divided into a main brake used while driving and a parking brake used to maintain a parked state.

Conventionally, the driver has been used to operate the parking brake by manually manipulating the handbrake provided in the driver's seat and pulling the parking cable. There was a problem that it was inconvenient to use. Accordingly, an electronic parking brake operated electronically has recently been applied.

The electronic parking brake is configured to pull a parking cable using a motor to realize a parking braking force. Here, since the electric forklift has a heavy load and loads a heavy load, it must have excellent parking braking power. Therefore, it is necessary to generate a high braking force by pulling the parking cable with great force.

A driving motor is installed on the front wheels of the electric forklift, that is, a left front wheel and a right front wheel, respectively, and a parking brake is installed on each of the left front wheel and the right front wheel. That is, parking cables must be connected to the left and right front wheels, respectively, and required parking braking force must be realized by pulling two cables.

However, the existing electronic parking brake could not provide a load to realize the parking braking force required for medium-sized or larger electric forklift trucks, and electrical components such as batteries, hydraulic oil tanks, cables, and harnesses as well as driving motors installed on the front wheels are used for electric forklift trucks. There is a problem that it is difficult to install the electronic parking brake because it must be mounted on the body frame of the vehicle. Accordingly, it is more difficult to install a plurality of electronic parking brakes to implement parking braking force on the left and right front wheels, respectively. In order to solve this problem, the cost increases because the width of the forklift body needs to be increased.

On the other hand, when the parking cable is pulled by a certain distance to generate a large braking force, but when deformation such as stretching of the parking cable occurs, the parking braking force is not equally transmitted to the left and right front wheels, or the required parking braking force is not implemented.

An electronic parking brake for an electric forklift according to an embodiment of the present invention implements parking braking force so that a large force is exerted with a small force, or it is possible to implement sufficient parking braking force by increasing the moving distance compared to the transmitted load.

According to one aspect of the present invention, in an electronic parking brake for an electric forklift that is electronically operated to operate a parking lever provided on a front wheel, a brake module that converts rotational force into linear motion to operate an operating cable to operate the parking lever ; a power transmission unit to which a parking cable connected to the parking lever and the operation cable are connected, and which transmits a pulling force of the brake module to the parking cable; An electronic parking brake for an electric forklift including an electronic control unit controlling the brake module may be provided.

In addition, the power transmission unit has a predetermined length, and one end is coupled via a first rotation shaft to be rotatable from the body frame of the electric forklift; and an operating lever connected to the operating cable and coupled to the other end of the rotating lever via a second rotating shaft so as to rotate the rotating lever at a predetermined angle, wherein the parking cable is connected to the first rotating shaft and the parking cable. It may be positioned between the second pivot shaft and coupled to the pivot lever via the third pivot shaft.

In addition, the first rotation shaft, the third rotation shaft, and the second rotation shaft disposed from one end to the other end of the rotation lever may be provided as a two-class lever structure that sequentially functions as a fulcrum point, an action point, and a load point.

The power transmission unit according to another embodiment of the present invention has a predetermined length, one end is coupled via a first rotational shaft so as to be rotatable from the body frame of the electric forklift, and the other end is connected to the parking cable via a third rotational shaft Rotation lever coupled to; and an operating lever connected to the operating cable and coupled to the rotating lever and a second rotating shaft to rotate the rotating lever at a predetermined angle, wherein the operating lever is connected to the first rotating shaft at a third rotation. It can be coupled to be positioned between the coax.

In addition, the first rotation shaft, the second rotation shaft, and the third rotation shaft disposed from one end to the other end of the rotation lever may be provided as a three-class lever structure that sequentially functions as a support point, a load point, and an action point.

In addition, the operating lever may include a first coupling portion connected to the operating cable; and a pair of second coupling portions branching off from the first coupling portion to be coupled at both sides of the rotation lever and extending.

In addition, a position sensor may be fixed to the body frame so as to be adjacent to the power transmission unit and detect an operation of the rotation lever.

In addition, a plurality of mounting parts for respectively supporting the operation cable, the parking cable, the rotation lever, and the position sensor may be provided, and the plurality of mounting parts may be fixed to the vehicle body frame.

In addition, the brake module, the housing; a motor provided in the housing and generating rotational force; a reducer connected to the rotation shaft of the motor to enable power transmission; and a spindle unit having a nut that rotates by receiving rotational force from the speed reducer and a screw that is screwed with the nut and converts rotational motion into linear motion, wherein the screw moves along with the linear motion of the screw. The operating cable may be connected to the end.

An electronic parking brake for an electric forklift according to an embodiment of the present invention improves the connection structure with a parking cable to realize parking braking force so that a large force is exerted with a small force, or to increase the moving distance compared to the load transmitted to provide sufficient parking braking force can be realized. Accordingly, it is possible to provide the required parking braking force, thereby reducing the number of modules generating the parking braking force, ensuring ease of installation and reducing cost.

In addition, it can be conveniently used by braking using a motor compared to the existing manually operated parking brake, and space utilization can be improved by reducing the space of the conventional parking lever provided in the driver's seat.

The present invention will be specifically described by the drawings below, but since these drawings show preferred embodiments of the present invention, the technical spirit of the present invention should not be construed as being limited to the drawings.
1 is a plan view schematically illustrating a state in which an electronic parking brake according to an embodiment of the present invention is installed on a body frame of an electric forklift.
2 is a perspective view illustrating a state in which an electronic parking brake according to an embodiment of the present invention is installed on a body frame of an electric forklift.
3 is a detailed view of a brake module provided in an electronic parking brake according to an embodiment of the present invention.
4 is a perspective view illustrating a state in which an operating cable and a parking cable are connected to a power transmission unit provided in an electronic parking brake according to an embodiment of the present invention.
5 is a side view illustrating a power transmission unit provided in an electronic parking brake according to an embodiment of the present invention.
6 is an operating state diagram of FIG. 5 .
7 is a view showing a state in which an operating cable and a parking cable are connected to a power transmission unit provided in an electronic parking brake according to another embodiment of the present invention.
8 is an operating state diagram of FIG. 7 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention may be embodied in other forms without being limited to only the embodiments presented herein. In the drawings, in order to clarify the present invention, illustration of parts irrelevant to the description may be omitted, and the size of components may be slightly exaggerated to aid understanding.

1 is a plan view schematically showing a state in which an electronic parking brake according to an embodiment of the present invention is installed on a body frame of an electric forklift, and FIG. 2 is a plan view showing an electronic parking brake according to an embodiment of the present invention installed on a body frame of an electric forklift. It is a perspective view showing a state installed in, Figure 3 is a detailed view of the brake module provided in the electronic parking brake according to an embodiment of the present invention, Figure 4 is a power provided in the electronic parking brake according to an embodiment of the present invention A perspective view showing a state in which an operating cable and a parking cable are connected to a transmission unit, FIG. 5 is a side view showing a power transmission unit provided in an electronic parking brake according to an embodiment of the present invention, and FIG. 6 is an operating state diagram of FIG. 5 .

1 to 6, the electronic brake 1 for an electric forklift according to an embodiment of the present invention includes a brake module 100 that generates a driving force to implement a parking braking force, and a parking cable 20 that transmits the driving force It may include an electronic control unit 400 that controls the power transmission unit 200 and the brake module 100 to be transmitted to. The electronic parking brake 1 may be installed on the body frame 10 of the electric forklift. That is, the brake module 100, the power transmission unit 200, and the electronic control unit 400 may be installed inside the body frame 10 forming the stem of the electric forklift so as not to be exposed from the outside of the electric forklift.

The body frame 10 includes a pair of side frames 11 provided on both sides, a front vertical frame 12 supporting the pair of side frames 11 at the front, and a pair of side frames at the rear end. It may include a rear vertical frame 13 supporting the (11) and an intermediate vertical frame 14 supporting a pair of side frames 11 between the front vertical frame 12 and the rear vertical frame 13. . Here, a front wheel and a mast assembly are provided at the front of the body frame 10, and a rear wheel and a counterweight are assembled at the rear. Since these mast assemblies, counterweights, etc. are well-known technologies installed in forklifts, they will be described in detail. On the other hand, although not shown, parking brakes are provided on the left and right front wheels, respectively, and the parking cables 20 are respectively connected to parking levers provided on each parking brake.

The brake module 100 may include a housing 110, a motor 120, a reducer 130 and a spindle unit 140, and an operating cable 150 connected to the screw 145 of the spindle unit 140. have.

The housing 110 is installed on the body frame 10 and is formed to have a predetermined storage space therein. As shown, the housing 110 is shown as being installed on the left side frame 11 of the pair of side frames 11, but is not limited thereto and may be installed on the right side frame 11.

The motor 120 may be provided as an electric motor capable of forward and reverse rotation, and may be driven by receiving power from the outside or by receiving power from a battery provided in the electric forklift. The operation of the motor 120 may be controlled by the electronic control unit 140. The rotational force generated by the motor 120 is transmitted to the reduction gear 130 through the rotational shaft 123.

The reducer 130 is provided so that a plurality of gears are meshed with each other and transmits the rotational force by amplifying the rotational torque through the finally output gear. Here, the reducer 130 is shown as having a structure of a spur gear assembly, but is not limited thereto, and various gear assembly structures may be applied as long as rotational force can be transmitted to the spindle unit 140.

The spindle unit 140 pulls or releases the operating cable 150 while operating in conjunction with the reducer 130. The spindle unit 140 includes a nut 143 that rotates by receiving rotational force from the reducer 130 and a screw 145 that is screwed with the nut 143 and converts rotational motion into linear motion.

The nut 143 has a hollow center in the longitudinal direction, and a thread is formed in the hollow for screwing with the screw 145.

The screw 145 has a predetermined length, and a screw thread is formed on the outer circumferential surface so as to be screwed into the hollow of the nut 143. When the nut 143 rotates, the screw 145 is provided in a state in which rotation is limited so as to linearly move in the hollow direction of the nut 143. Accordingly, the nut 143 advances and retreats according to the direction of rotation and makes a linear motion. For example, when the nut 143 rotates clockwise, the screw 145 moves inside the housing 110, and when the nut 143 rotates counterclockwise, the screw 145 rotates the housing 145. can be moved outward. An operating cable 150 is connected to the end of the screw 145 and provided to move along with the linear movement of the screw 145.

The operation cable 150 is connected to the power transmission unit 200 to be described later, and operates the power transmission unit 200 to pull or release the parking cable 20 so as to generate parking braking force or release the parking braking force.

The power transmission unit 200 is provided so that the parking cable 20 connected to the parking lever and the operating cable 150 are connected to each other, and serves to transmit the pulling force of the brake module 100 to the parking cable 20. . The power transmission unit 200 may include a rotation lever 210 and an operating lever 220 .

The rotation lever 210 has a predetermined length, and one end may be rotatably coupled from the vehicle body frame 10 . At this time, the rotation lever 210 may be coupled to the mounting portion 503 fixed to the body frame 10 via the first rotation shaft P1, and the mounting portion 503 will be described again below.

The operation lever 220 may be connected to the operation cable 150 and coupled to the other end of the rotation lever 210 via the second rotation shaft P2 so as to rotate the rotation lever 210 at a predetermined angle. The operating lever 220 may include a first coupling portion 221 connected to the operating cable 150 and a pair of second coupling portions 222 extending and branching from the first coupling portion 221. can That is, in the operation lever 220, a first coupling part 221 formed at one end is connected to the operation cable 150, and a pair of second coupling parts 222 formed at the other end are connected to the rotation lever 210. can be combined Here, the pair of second coupling parts 222 are spaced apart from each other at a predetermined interval and coupled from both sides of the rotation lever 210 via the second rotation shaft P2.

When the rotation lever 210 of the power transmission unit 200 is operated by the operation lever 220, the rotation lever 210 and the parking cable 20 are connected so that power is transmitted to the parking cable 20. The parking cable 20 may be coupled to the rotation lever 210 via the third rotation shaft P3 so as to be located between the first rotation shaft P1 and the second rotation shaft P2. Accordingly, the first rotation axis P1, the third rotation axis P3, and the second rotation axis P2 are sequentially coupled from one end to the other end of the rotation lever 210 to function as a fulcrum point, an action point, and a load point done to do

Specifically, the first rotational shaft P1 supports the rotation of the rotational lever 210 and is provided as a fixed fulcrum, and the second rotational shaft P2 is a load to which force for rotating the rotational lever 210 is transmitted. It is provided as a point, and the third rotation axis (P3) is provided as an operating point operated according to the rotation of the rotation lever (210). That is, the power transmission unit 200 is connected to the operation cable 150 and the parking cable 20 to have a two-class lever structure.

As the power transmission unit 200 is provided in a two-class lever structure, it is possible to exert a large force with a small force. That is, the distance between the first rotational axis (P1, fulcrum) and the second rotational axis (P2, load point) compared to the distance between the first rotational axis (P1, fulcrum) and the third rotational axis (P3, action point) As it is provided to have a long distance, it is possible to exert a greater force than the force given when rotating the pivoting member 210. Therefore, when the actuating cable 150 is pulled by the brake module 100, the actuating lever 220 connected to the actuating cable 150 moves and rotates the pivoting lever 210 at a predetermined level relative to the first pivotal axis P1. rotate the angle. Accordingly, the parking cable 20 connected to the middle of the rotation lever 210 is pulled to generate parking braking force. This means that a large force is required to pull the two parking cables 20 connected to the parking levers of the left and right front wheels to generate the required parking braking force, and medium-sized or larger electric forklifts have higher braking power than small electric forklifts. because it is required Accordingly, as the power transmission unit 200 according to an embodiment of the present invention is provided to exert a large force with a small force, it can be operated to implement sufficient parking braking force through one brake module 100.

According to an embodiment of the present invention, when the parking braking force is implemented by the power transmission unit 200, a position sensor 300 for detecting whether the power transmission unit 200 is operated may be further included. The position sensor 300 is installed on the body frame 10 so as to be adjacent to the power transmission unit 200 . The position detection sensor 300 is positioned in a direction in which the rotation lever 210 is rotated toward generating a parking braking force, and detects the movement. For example, the position sensor 300 may be provided and used as various types of sensors such as an optical sensor, a position sensor, and a Hall IC. The position detection sensor 300 may be connected to the electronic control unit 400 to transmit a detected signal, and the electronic control unit 400 may control the brake module 100 according to the received signal or require parking braking force. If this does not occur, it may be arranged to perform follow-up actions such as warning the driver.

The electronic control unit 400 controls the brake module 100 by receiving signals detected by the position sensor 300 . In addition, the electronic control unit 400 may be provided to control other electronic components provided in the electric forklift. This electronic control unit 400 is a well-known technology commonly used in vehicles as well as forklifts, and detailed description thereof will be omitted.

Meanwhile, the aforementioned components may be provided to be stably installed in the body frame 10 through the plurality of mounting parts 501 , 502 , 503 , and 504 . For example, the plurality of mounting parts 501, 502, 503, 504 support the operating cable 150 and simultaneously support the first mounting part 501 fixed to the side frame 10 and the two parking cables 20, A second mounting part 502 fixed to the side frame 10, a third mounting part 503 fixed to the side frame 10 while supporting one end of the rotation lever 210 of the power transmission part 200, and a position sensor It supports the 300 and may include a fourth mounting part 504 fixed to the side frame. These first to fourth mounting parts 501 to 504 may be positioned and installed close to each other so that a coupling structure state between supporting components can be stably maintained.

As described above, the electronic parking brake 1 of the present invention has been shown and described as performing a parking braking force by exerting a large force with a small force through the power transmission unit 200 having a two-class lever structure, but is limited to this However, the parking braking force may be realized by increasing the moving distance compared to the transmitted load. An example of this is shown in FIGS. 7 and 8 . Here, the same reference numerals as in the previously shown drawings indicate members that perform the same functions.

7 is a view showing a state in which an operating cable and a parking cable are connected to a power transmission unit provided in an electronic parking brake according to another embodiment of the present invention, and FIG. 8 is an operating state diagram of FIG. 7 .

7 and 8, the power transmission unit 200' according to another embodiment of the present invention is provided so that the parking cable 20 and the operating cable 150 connected to the parking lever are connected, respectively, and the brake module ( 100) serves to transmit the pulling force to the parking cable 20. The power transmission unit 200' may include a rotation lever 210 and an operating lever 220.

According to this embodiment, the rotation lever 210 has a predetermined length, one end is coupled via the first rotation shaft P1 so as to be able to rotate from the body frame 10, and the parking cable 20 is connected to the other end to the third It is coupled via the rotation axis (P3).

The operation lever 220 is connected to the operation cable 150 and coupled to the rotation lever 210 through the second rotation shaft P2 so as to rotate the rotation lever 210 at a predetermined angle. The operating lever 220 includes a first coupling portion 221 connected to the operating cable 150 and a pair of second coupling portions 222 extending and branching from the first coupling portion 221. . In addition, the operating lever 220 is disposed between the first rotational axis P1 and the third rotational axis P3 so that the second coupling part 222 is positioned on both sides of the rotational lever 210 to the second rotational axis ( P2) is coupled through the medium.

In this way, the first rotation axis P1, the second rotation axis P2, and the third rotation axis P3 are sequentially coupled from one end to the other end of the rotation lever 210 to perform the functions of the fulcrum point, load point, and action point. made to perform

Specifically, the first rotational shaft P1 supports the rotation of the rotational lever 210 and is provided as a fixed fulcrum, and the second rotational shaft P2 is a load to which force for rotating the rotational lever 210 is transmitted. It is provided as a point, and the third rotation axis (P3) is provided as an operating point operated according to the rotation of the rotation lever (210). That is, the power transmission unit 200' is connected to the operation cable 150 and the parking cable 20 to have a three-class lever structure.

As the power transmission unit 200' is provided in a three-class lever structure, it is possible to increase the movement distance compared to the transmitted load. That is, the distance between the first rotational axis (P1, fulcrum) and the third rotational axis (P3, action point) compared to the distance between the first rotational axis (P1, fulcrum) and the second rotational axis (P2, load point) As it is provided to have a long distance, it is possible to increase the movement distance of the action point when rotating the pivoting member 210. Therefore, when the actuating cable 150 is pulled by the brake module 100, the actuating lever 220 connected to the actuating cable 150 moves and rotates the pivoting lever 210 at a predetermined level relative to the first pivotal axis P1. rotate the angle. Accordingly, the parking cable 20 connected to the other end of the rotation lever 210 is pulled to generate parking braking force. This makes it possible to implement the required parking braking force by sufficiently pulling the parking cable 20 even if deformation such as stretching of the parking cable 20 connected to the parking levers of the left and right front wheels, respectively, occurs.

Additionally, the power transmission unit 200' having a three-class lever structure is preferably applied to a small electric forklift that requires a lower braking force than a medium or larger forklift. However, if the load generated from the brake module 100 meets the requirements for realizing parking braking force by rotating the rotation lever 210, it may be applied and used to a medium-sized or larger electric forklift.

As described above, although the present invention has been described by the limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the following by those skilled in the art to which the present invention belongs Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

1 : Electronic parking brake
10: body frame
20: parking cable
100: brake module
200: power transmission unit
300: position detection sensor
400: electronic control unit

Claims (9)

In the electronic parking brake for an electric forklift that is electronically operated to operate a parking lever provided on the front wheel,
a brake module operating an operating cable by converting rotational force into linear motion to operate the parking lever;
a power transmission unit to which a parking cable connected to the parking lever and the operation cable are connected, and which transmits a pulling force of the brake module to the parking cable; and
An electronic parking brake for an electric forklift including an electronic control unit controlling the brake module. According to claim 1,
The power transmission unit,
a rotational lever having a predetermined length and having one end coupled via a first rotational shaft so as to be rotatable from the body frame of the electric forklift; and
An operating lever connected to the operating cable and coupled to the other end of the rotating lever via a second pivot shaft so as to rotate the rotating lever at a predetermined angle,
The parking brake for an electric forklift is coupled to the rotation lever via a third rotation shaft so that the parking cable is positioned between the first rotation shaft and the second rotation shaft. According to claim 2,
The first rotation axis, the third rotation shaft, and the second rotation shaft disposed from one end of the rotation lever to the other end are provided with a two-class lever structure that sequentially performs the functions of a fulcrum point, an action point, and a load point. Electronic parking for electric forklifts brake. According to claim 1,
The power transmission unit,
a pivoting lever having a predetermined length, one end of which is rotatably coupled from the body frame of the electric forklift truck through a first pivotal axis, and the other end of which the parking cable is coupled via a third pivotal axis; and
An operating lever connected to the operating cable and coupled to the rotation lever and a second rotation shaft so as to rotate the rotation lever at a predetermined angle,
The operating lever is an electronic parking brake for an electric forklift coupled to be positioned between the first rotation axis and the third rotation axis. According to claim 4,
The first rotational axis, the second rotational shaft, and the third rotational shaft disposed from one end to the other end of the rotational lever are provided with a three-class lever structure that sequentially performs the functions of a fulcrum point, a load point, and an action point. Electronic parking for electric forklifts brake. According to claim 2 or 4,
The operating lever,
a first coupling part connected to the operating cable; and
An electronic parking brake for an electric forklift having a pair of second coupling portions extending and branching from the first coupling portion to be engaged at both sides of the rotation lever. According to claim 2 or 4,
The electronic parking brake for an electric forklift further comprising a position sensor fixed to the body frame to be adjacent to the power transmission unit and detecting an operation of the rotation lever. According to claim 7,
A plurality of mounting parts respectively supporting the operating cable, the parking cable, the rotation lever, and the position sensor,
An electronic parking brake for an electric forklift in which a plurality of mounting parts are fixed to the body frame. According to claim 1,
The brake module,
housing;
a motor provided in the housing and generating rotational force;
a reducer connected to the rotation shaft of the motor to enable power transmission; and
A spindle unit having a nut that rotates by receiving rotational force from the reducer and a screw that is screwed with the nut and converts rotational motion into linear motion,
An electronic parking brake for an electric forklift in which the operating cable is connected to the end of the screw so as to move together with the linear motion of the screw.

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