Electro-hydraulic composite brake pedal assembly of electric forklift

Abstract

The invention discloses an electro-hydraulic composite brake pedal assembly of an electric forklift, and relates to the technical field of forklifts, a first brake pedal and a second brake pedal are hinged and mounted on a fixed bracket, and the two pedals are respectively used for being treaded during braking and are reset through a first return spring; the angle sensor obtains the swing angle of the first brake pedal, the controller calculates the brake torque of the vehicle according to the angle signal of the first brake pedal and the vehicle state, the motor is preferentially adjusted for braking, and when the needed braking force exceeds the motor braking range, the proportional valve is controlled to superimpose hydraulic braking; hydraulic braking is additionally added on the basis of motor braking, and the braking efficiency is ensured; when the second brake pedal is treaded, the brake valve is triggered to achieve hydraulic braking, motor braking failure can be prevented, and dual braking guarantee is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of forklifts, and more particularly to an electro-hydraulic composite brake pedal assembly of an electric forklift. BACKGROUND

[0002] At present, most electric forklifts adopt a single-pedal control form, and the motor adopts a speed control mode, that is, the vehicle accelerates when the accelerator pedal is stepped on, and the vehicle decelerates and recovers kinetic energy when the accelerator pedal is released, and the braking intensity is determined by the speed of releasing the accelerator pedal, if the accelerator pedal is released gently, it is mild braking and less energy recovery, and if the accelerator pedal is released quickly, it is rapid braking and more energy recovery. However, the single-pedal control form has poor driving comfort, and is not suitable for large-tonnage electric forklifts.

[0003] For large-tonnage counterbalanced electric forklifts, if full-motor braking is adopted without the participation of hydraulic braking, on the one hand, the braking distance cannot meet the requirements, and on the other hand, once the electric braking fails, the vehicle braking safety cannot be guaranteed.

[0004] Therefore, most large-tonnage forklifts adopt the pedal form of independent accelerator and brake pedals, the brake pedal adopts hydraulic braking, and the motor potential energy recovery is realized by installing an angle sensor on the brake pedal. However, by using the above braking mode, the hydraulic braking intervenes too early, which makes it difficult for the motor and hydraulic composite braking to balance the energy recovery efficiency and the operation feeling and comfort of vehicle driving. SUMMARY

[0005] The core of the present application is to provide an electro-hydraulic composite brake pedal assembly of an electric forklift, the first brake pedal adopts electro-hydraulic composite braking, and the motor braking is preferentially adopted, so that the kinetic energy recovery is realized to a greater extent, and the second brake pedal adopts pure hydraulic braking to ensure the stability of braking, and the specific scheme is as follows:

[0006] An electro-hydraulic composite brake pedal assembly of an electric forklift, comprising:

[0007] A fixed support fixedly assembled to the forklift;

[0008] A first brake pedal hingedly connected to the fixed support for stepping on during braking and reset by a first return spring;

[0009] A second brake pedal hingedly connected to the fixed support for stepping on during braking and reset by a first return spring;

[0010] An angle sensor for acquiring the swing angle of the first brake pedal;

[0011] A brake valve is installed on the fixed support below the second brake pedal, which is used to trigger the brake valve to change the opening degree of the brake valve.

[0012] The first brake pedal adopts electro-hydraulic composite braking, the controller calculates the braking torque of the vehicle according to the first brake pedal angle signal and the vehicle state, preferentially mobilizes the motor to brake, and controls the proportional valve to superimpose hydraulic braking when the required braking force exceeds the motor braking range; the second brake pedal adopts hydraulic braking.

[0013] Optionally, one end of the swing rod is hingedly installed at the bottom of the first brake pedal, and the other end of the swing rod is installed with a first roller for rolling contact with the fixed support; the swing rod is reset by a second return spring;

[0014] The angle sensor is installed on the first brake pedal for detecting the angle of the swing rod.

[0015] Optionally, a first limit pin is installed at the bottom of the first brake pedal for blocking the swing limit angle of the swing rod.

[0016] Optionally, a limit plate is installed on the fixed support, and the first roller always contacts the limit plate.

[0017] Optionally, a second roller is hingedly arranged at the bottom of the second brake pedal for pressing the brake valve.

[0018] Optionally, a second limit pin is installed on the fixed support, located at the back of the second brake pedal, for limiting the swing limit angle of the second brake pedal.

[0019] Optionally, an extension plate is fixedly connected to the second brake pedal, and a linkage is arranged at the back of the extension plate for linkage cooperation with the first brake pedal.

[0020] The first brake pedal swings by a preset angle and drives the second brake pedal to swing downward synchronously through the linkage.

[0021] Optionally, a hinged shaft is installed on the fixed support, and the first brake pedal and the second brake pedal are respectively hinged to the hinged shaft.

[0022] Optionally, the extension plate is hinged to the hinged shaft.

[0023] Optionally, the first brake pedal is arranged on the left side of the second brake pedal.

[0024] This invention provides an electro-hydraulic composite brake pedal assembly for an electric forklift. A first brake pedal and a second brake pedal are hinged to a fixed bracket. The two pedals are used for braking and are reset by a first return spring. An angle sensor obtains the swing angle of the first brake pedal. The controller calculates the vehicle's braking torque based on the first brake pedal angle signal and the vehicle's status, prioritizing motor braking. When the required braking force exceeds the motor braking range, a proportional valve is controlled to superimpose hydraulic braking, adding hydraulic braking on top of motor braking to ensure braking efficiency. When the second brake pedal is pressed, a brake valve is triggered to achieve hydraulic braking, preventing motor braking failure and providing dual braking protection. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 Axonometric schematic diagram of the electro-hydraulic composite brake pedal assembly for an electric forklift;

[0027] Figure 2 for Figure 1 Based on the existing structure, an isometric schematic diagram of the linkage component is added;

[0028] Figure 3A A front view of the electro-hydraulic composite brake pedal assembly for an electric forklift;

[0029] Figure 3B for Figure 3A Cross-sectional view;

[0030] Figure 4A This is an isometric view of the first brake pedal;

[0031] Figure 4B for Figure 4A Cross-sectional view of the structure.

[0032] The image includes:

[0033] Fixed bracket 10; limiting plate 110; hinge shaft 120; first return spring 130; second limiting pin 140;

[0034] First brake pedal 20; swing arm 210; first roller 220; second return spring 230; first limit pin 240;

[0035] Second brake pedal 30; second roller 310; extension plate 320; linkage 330;

[0036] Angle sensor 40;

[0037] Brake valve 50. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solution of the present invention, the electric forklift electro-hydraulic composite brake pedal assembly of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Combination Figure 1 As shown, the present invention provides an electro-hydraulic composite brake pedal assembly for electric forklifts, which is used in electric forklifts and is equipped with two sets of pedal structures, namely a first brake pedal and a second brake pedal. By stepping on different pedals, two different braking modes can be achieved.

[0040] The electric forklift electro-hydraulic composite brake pedal assembly of the present invention includes a fixed bracket 10, a first brake pedal 20, a second brake pedal 30, an angle sensor 40, a brake valve 50, and other structures.

[0041] The fixed bracket 10 is the basic structure of the entire electro-hydraulic composite brake pedal assembly of the electric forklift, and other components are mounted on the fixed bracket 10. The fixed bracket 10 is fixedly mounted to the forklift body, while other movable structures move relative to the fixed bracket 10.

[0042] The first brake pedal 20 is hinged to the fixed bracket 10 and can swing about a pivot relative to the fixed bracket 10. The first brake pedal 20 is used for braking. When the first brake pedal 20 is pressed and swings, it triggers a braking signal to achieve braking. The greater the downward swing of the first brake pedal 20, the greater the braking force. When the first brake pedal 20 is released, it returns to its original position through the first return spring 130. The first brake pedal 20 is an electro-hydraulic hybrid brake, which first uses motor kinetic energy recovery braking, and then adds hydraulic braking when the motor braking cannot meet the braking force requirements.

[0043] The controller calculates the vehicle's braking torque based on the 20° angle signal from the first brake pedal and the vehicle's status, prioritizing the use of the electric motor for braking. When the required braking force exceeds the electric motor's braking range, the controller controls the proportional valve to superimpose hydraulic braking; the larger the opening of the proportional valve, the greater the hydraulic braking force provided.

[0044] The second brake pedal 30 is hinged to the fixed bracket 10 and can swing about a pivot relative to the fixed bracket 10. The second brake pedal 30 is used for braking; when it is pressed and swings, it triggers a braking signal to achieve braking. The greater the downward swing of the second brake pedal 30, the greater the braking force. When the second brake pedal 30 is released, it returns to its original position via the first return spring 130. The second brake pedal 30 is a purely hydraulic brake, and no electric motor braking is involved in the braking process.

[0045] It should be noted that the first brake pedal 20 and the second brake pedal 30 are respectively provided with a first return spring 130, which is used to elastically reset the first brake pedal 20 or the second brake pedal 30.

[0046] Angle sensor 40 is used to acquire the swing angle of the first brake pedal 20. The detection signal from angle sensor 40 reflects the braking force generated when the first brake pedal 20 is depressed. The larger the angle change value detected by angle sensor 40, the greater the braking force control signal issued by the controller. First, the motor recovers kinetic energy for braking. When the motor braking cannot further meet the braking demand, hydraulic braking is superimposed.

[0047] In this process, the braking force is first provided by the kinetic energy recovery of the motor, and the braking force of the motor braking is directly proportional to the swing angle of the first brake pedal 20. When the required braking force exceeds the range of motor braking, hydraulic braking is gradually applied on the basis of motor braking, so that the braking force generated by the first brake pedal 20 forms a smooth transition. The hydraulic braking will not intervene too early. The motor and hydraulic combined braking can take into account both energy recovery efficiency and the driving feel and comfort of the vehicle.

[0048] The brake valve 50 is mounted on the fixed bracket 10 and located below the second brake pedal 30. When the second brake pedal 30 is pressed and swings downward, the second brake pedal 30 triggers the brake valve 50 to change the opening degree of the brake valve 50. The greater the swing angle of the second brake pedal 30, the greater the opening degree of the brake valve 50, and the greater the hydraulic braking force provided.

[0049] The electro-hydraulic hybrid brake pedal assembly for electric forklifts provided by this invention includes two braking pedals, a first brake pedal 20 and a second brake pedal 30, each employing a different braking mechanism. In use, the first brake pedal 20 is used first to brake, prioritizing motor braking to recover some kinetic energy, while hydraulic braking is superimposed to ensure braking capability. In emergency situations, such as motor brake failure, the second brake pedal 30 can be used to provide braking, ensuring safe and effective braking.

[0050] Combination Figure 1 , Figure 4A As shown, one end of a swing arm 210 is hinged to the bottom of the first brake pedal 20, and the other end of the swing arm 210 is fitted with a first roller 220. Specifically, a hinge seat is provided at the bottom of the first brake pedal 20 with the swing arm 210, and the swing arm 210 is hinged to the hinge seat via a pivot. The swing arm 210 can swing around the pivot at the top, thereby driving the first roller 220 at the bottom to swing synchronously. The first roller 220 is rotatably mounted on the bottom end of the swing arm 210 via a pivot, and the first roller 220 can rotate relative to the swing arm 210.

[0051] The first roller 220 is used to roll and contact the fixed bracket 10. The first roller 220 is always in contact with the fixed bracket 10, and the swing arm 210 is reset by the second return spring 230. When the first brake pedal 20 swings relative to the fixed bracket 10, the swing arm 210 swings relative to the first brake pedal 20 because the first roller 220 is in contact with the fixed bracket 10, and the first roller 220 rolls relative to the fixed bracket 10.

[0052] An angle sensor 40 is installed on the first brake pedal 20 to detect the angle of the swing arm 210. The angle of the first brake pedal 20 is reflected by detecting the angle of the swing arm 210. The larger the swing angle of the first brake pedal 20, the greater the angle of the swing arm 210.

[0053] Since the rear bottom of the first brake pedal 20 is hinged to the fixed bracket 10, it is difficult to set up an angle detection structure. However, the angle sensor 40 is installed at the bottom front end of the first brake pedal 20, and the distance between the bottom front end of the first brake pedal 20 and the fixed bracket 10 is larger, providing more installation space.

[0054] Combination Figure 4A As shown, a first limiting pin 240 is installed at the bottom of the first brake pedal 20. The first limiting pin 240 is used to block the swing limit angle of the swing rod 210. When the swing rod 210 reaches the maximum swing angle, it contacts the first limiting pin 240 and cannot continue to rotate. By setting two first limiting pins 240, the swing rod 210 can be made to swing within a certain angle range.

[0055] Install the limiting plate 110 on the fixed bracket 10, and combine it with Figure 1 , Figure 2 As shown, the limiting plate 110 is an L-shaped bent plate. The horizontal surface of the limiting plate 110 is assembled to the fixed bracket 10 by welding or other methods. The vertical surface of the limiting plate 110 protrudes upward from the fixed bracket 10, which can prevent the swing rod 210 from shifting laterally. The first roller 220 is always in contact with the horizontal surface of the limiting plate 110, providing a flat rolling surface for the first roller 220. Furthermore, the height of the first roller 220 can be adjusted by adjusting the thickness of the horizontal plate of the limiting plate 110, thereby adjusting the initial angle of the first brake pedal 20.

[0056] The bottom of the second brake pedal 30 is hinged to a second roller 310, which is combined with... Figure 1 , Figure 2As shown, a hinge seat is fixedly installed on the bottom surface of the second brake pedal 30, and a second roller 310 is rotatably mounted on the hinge seat. The second roller 310 can rotate relative to the second brake pedal 30. The second roller 310 is used to press the brake valve 50. When the second roller 310 contacts the brake valve 50, the second roller 310 rolls relative to the brake valve 50 to avoid wear on the brake valve 50 caused by the second brake pedal 30.

[0057] A second limiting pin 140 is installed on the fixed bracket 10. The second limiting pin 140 protrudes upward from the fixed bracket 10 and is located on the back of the second brake pedal 30. It is used to limit the swing limit angle of the second brake pedal 30. When the second brake pedal 30 swings downward and contacts the second limiting pin 140, it reaches the limit position.

[0058] It should be noted that both the second limit pin 140 and the first limit pin 240 can be bolted, and the limiting angle of the second limit pin 140 and the first limit pin 240 can be adjusted by turning the bolts.

[0059] Based on any of the above technical solutions and their combinations, the second brake pedal 30 is fixedly connected to the extension plate 320, combined with... Figure 3A As shown, the extension plate 320 is fixed on the second brake pedal 30, and the extension plate 320 extends toward the first brake pedal 20. The height of the extension plate 320 is less than the height of the second brake pedal 30.

[0060] Combination Figure 2 As shown, a linkage 330 is provided on the back of the extension plate 320. The linkage 330 is fixed to the extension plate 320 and extends to the bottom of the first brake pedal 20. When the first brake pedal 20 is in the initial position, there is a gap between it and the linkage 330.

[0061] The linkage 330 is used to work in conjunction with the first brake pedal 20. When the first brake pedal 20 swings to a preset angle, the linkage 330 drives the second brake pedal 30 to swing downward synchronously, thereby causing the second brake pedal 30 to press the brake valve 50, and hydraulic braking is achieved through the brake valve 50.

[0062] By setting the linkage 330, the brake valve 50 can be triggered by the action of the first brake pedal 20, ensuring that hydraulic braking can be triggered by the brake valve 50 in an emergency, or ensuring safe and reliable braking when no proportional valve is set or the proportional valve fails.

[0063] Combination Figure 3BAs shown, a hinge shaft 120 is mounted on the fixed bracket 10. The first brake pedal 20 and the second brake pedal 30 are respectively hinged to the hinge shaft 120. The first brake pedal 20 and the second brake pedal 30 are respectively hinged and assembled on the same hinge shaft 120, which improves the integration and simplifies the assembly process. Bearings are respectively provided between the first brake pedal 20 and the hinge shaft 120, and between the second brake pedal 30 and the hinge shaft 120, to improve compliance and reduce wear.

[0064] Combination Figure 2 As shown, the extension plate 320 is hinged to the hinge shaft 120. Since the extension plate 320 extends toward the first brake pedal 20, the extension plate 320 is hinged to the hinge shaft 120 through a bearing, which can prevent tilting when stepping on the extension plate 320 and ensure stability.

[0065] Combination Figure 3A As shown, the first brake pedal 20 is located to the left of the second brake pedal 30, and the accelerator pedal can be installed on the right side of the second brake pedal 30. Of course, the relative positions of the first brake pedal 20 and the second brake pedal 30 can be interchanged.

[0066] This invention relates to an electro-hydraulic hybrid brake pedal assembly for electric forklifts, applicable to heavy-duty electric forklifts. The left pedal is an electro-hydraulic hybrid brake, while the right pedal is a pure hydraulic brake. The braking force is controlled by detecting the swing angle of the left pedal using a swing lever and an angle sensor. The right pedal directly controls the opening of the brake valve to adjust the hydraulic braking force. This improves braking comfort and energy recovery efficiency for the driver. The invention retains the mechanical structure of the hydraulic brake, effectively preventing emergency braking in case of electro-hydraulic brake failure, thus enhancing driving safety.

[0067] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electro-hydraulic composite brake pedal assembly for an electric forklift, characterized in that, include: Fixed bracket (10) is fixedly mounted on the forklift; The first brake pedal (20) is hinged to the fixed bracket (10) for use when braking and is reset by the first return spring (130); The second brake pedal (30) is hinged to the fixed bracket (10) for use when braking and is reset by the first return spring (130). An angle sensor (40) is used to obtain the swing angle of the first brake pedal (20); A brake valve (50) is mounted on the fixed bracket (10) and located below the second brake pedal (30). The second brake pedal (30) is used to trigger the brake valve (50) to change the opening degree of the brake valve (50). The first brake pedal (20) adopts electro-hydraulic hybrid braking. The controller calculates the vehicle's braking torque based on the angle signal of the first brake pedal (20) and the vehicle's status, prioritizes the motor for braking, and controls the proportional valve to superimpose hydraulic braking when the required braking force exceeds the motor's braking range; the second brake pedal (30) adopts hydraulic braking.

2. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 1, characterized in that, One end of a swing arm (210) is hinged to the bottom of the first brake pedal (20), and the other end of the swing arm (210) is fitted with a first roller (220). The first roller (220) is used to roll in contact with the fixed bracket (10); the swing arm (210) is reset by a second return spring (230). The angle sensor (40) is installed on the first brake pedal (20) to detect the angle of the swing arm (210).

3. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 2, characterized in that, A first limiting pin (240) is installed at the bottom of the first brake pedal (20), and the first limiting pin (240) is used to block and limit the swing limit angle of the swing rod (210).

4. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 2, characterized in that, A limiting plate (110) is installed on the fixed bracket (10), and the first roller (220) is always in contact with the limiting plate (110).

5. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 1, characterized in that, The bottom of the second brake pedal (30) is hinged to a second roller (310), which is used to press the brake valve (50).

6. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 1, characterized in that, The second limiting pin (140) is installed on the fixed bracket (10). The second limiting pin (140) is located on the back of the second brake pedal (30) and is used to limit the swing limit angle of the second brake pedal (30).

7. The electric forklift electro-hydraulic composite brake pedal assembly according to any one of claims 1 to 6, characterized in that, The second brake pedal (30) is fixedly connected to the extension plate (320), and a linkage member (330) is provided on the back of the extension plate (320). The linkage member (330) is used to cooperate with the first brake pedal (20). After the first brake pedal (20) swings to a preset angle, it drives the second brake pedal (30) to swing downward synchronously through the linkage (330).

8. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 7, characterized in that, The hinge shaft (120) is installed on the fixed bracket (10), and the first brake pedal (20) and the second brake pedal (30) are respectively hinged to the hinge shaft (120).

9. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 8, characterized in that, The extension plate (320) is hinged to the hinge shaft (120).

10. The electric forklift electro-hydraulic composite brake pedal assembly according to claim 7, characterized in that, The first brake pedal (20) is located to the left of the second brake pedal (30).

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