An electric forklift

Abstract

The present invention relates to the technical field of electric forklifts, and in particular provides an electric forklift. The electric forklift comprises a forklift body, a connection adjustment assembly and a fork assembly. The present invention can accurately adjust the length and angle of the fork assembly to achieve precise positioning and stable handling, reduce the risk of shaking and sliding of goods during handling, reduce the safety hazards caused by unstable goods through the cooperation of the hydraulic system and the cylinder, and can effectively and quickly adjust the length of the fork to adapt to goods of different sizes, thereby improving the flexibility and applicability of handling, improving the operating efficiency and safety of the forklift, and making the cargo handling process more efficient and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of electric forklifts, and in particular provides an electric forklift. Background Art

[0002] A battery forklift is a forklift that uses a battery as its source of power to drive the travel motor and the oil pressure system motor to achieve travel and loading and unloading operations. In many operating situations, the oil pressure system of existing battery forklifts still needs to keep the hydraulic pump in the oil pressure system running continuously to maintain system pressure, even when lifting and other operations are not required, resulting in additional power consumption, which in turn easily generates a large amount of parasitic power, causing the vehicle to generate additional energy consumption, resulting in reduced overall energy efficiency of the electric forklift. It will also cause delays or instability in operations that require quick response and precise control during the handling process, affecting the safe handling of goods and operational accuracy. Summary of the invention

[0003] Based on this, it is necessary to provide an electric forklift to solve at least one technical problem in the background technology.

[0004] An electric forklift comprises a forklift body, a connection adjustment component and a fork assembly. The connection adjustment component is installed on the outside of the forklift body, and the fork assembly is installed on the bottom of the connection adjustment component.

[0005] As a further improvement of the present invention, a hollow cavity is provided inside the forklift body, preset grooves are respectively provided at both ends of the outer bottom of the hollow cavity, and adjusting hydraulic cylinders are respectively provided on both sides of the bottom surface of the hollow cavity. The output shaft of the adjusting hydraulic cylinder passes through the preset groove and is convexly arranged outside the forklift body. A hydraulic adjustment shaft is rotatably provided at the bottom of the outer side of the forklift body, and adjustment connecting plates are respectively provided at both ends of the hydraulic adjustment shaft.

[0006] As a further improvement of the present invention, a connecting and adjusting assembly includes a connecting and adjusting frame, two vertical adjusting cylinders, a fork vertical mounting frame and a connecting and mounting frame, a connecting and mounting cross plate is convexly provided at the bottom inner side of the connecting and mounting cross plate, adjusting and mounting turntables are respectively convexly provided at both ends of the inner side of the connecting and mounting cross plate, the two adjusting and mounting turntables are respectively rotatably connected to the outer sides of the two adjusting connecting plates, a mounting cavity is concavely provided on the inner side of the connecting and adjusting frame, vertical mounting slide grooves are respectively concavely provided at both ends of the mounting cavity, connecting and mounting turntables are respectively convexly provided at the middle parts of the two ends of the connecting and adjusting frame, the two connecting and mounting turntables are respectively rotatably connected to the output shafts of the two adjusting hydraulic cylinders, the bottom ends of the two vertical adjusting cylinders are respectively mounted on the two ends of the inner top of the connecting and mounting cross plate, the two ends of the fork vertical mounting frame are respectively slidably mounted in the two vertical mounting slide grooves, and the two ends of the inner top of the fork vertical mounting frame are respectively connected to the bottom ends of the two vertical adjusting cylinders, and the connecting and mounting frame is mounted on the outer bottom of the fork vertical mounting frame.

[0007] As a further improvement of the present invention, the fork assembly includes two fork elements, a first drive motor, a second drive motor, a first synchronous transmission element and a second synchronous transmission element. The inner ends of the two fork elements are respectively installed at the two ends of the bottom outside of the connecting mounting frame, the first drive motor and the second drive motor are respectively installed at the bottom of the two fork elements, and the first drive motor and the second drive motor are staggered. The first synchronous transmission element is installed in the two fork elements, and the second synchronous transmission element is installed in the two fork elements.

[0008] As a further improvement of the present invention, each fork element includes a fixed fork, a first-level movable fork and a second-level movable fork, the inner end of the fixed fork is installed at one end of the bottom of the outer side of the connecting mounting frame, the fixed fork is hollow inside to form a transmission cavity, the inner end of the transmission cavity is respectively recessed with first rotating holes on both sides, the outer end of the transmission cavity is respectively recessed with second rotating holes on both sides, a plurality of transmission shafts are arranged along the length direction in the middle of the transmission cavity, each transmission shaft is provided with a first rotating gear, and the plurality of first rotating gears are meshed and connected with each other, a first movable slide groove is recessed at the top of the transmission cavity, and the bottom of the first-level movable fork is slidably installed in the first movable slide groove A connecting groove is concavely provided on the bottom surface of the first-stage movable fork, a spur rack is convexly provided on the top surface of the connecting groove, the spur rack is meshed and connected with a plurality of first rotating gears, transmission mounting grooves are respectively concavely provided in the middle of both ends of the connecting groove, a secondary transmission shaft is rotatably provided in the transmission mounting groove, a secondary transmission wheel is provided in the middle of the secondary transmission shaft, a second movable slide groove is concavely provided on the top surface of the first-stage movable fork, lifting seats are respectively convexly provided on the two ends of the top surface of the second movable slide groove, a third transmission wheel is rotatably provided on the top of each lifting seat, the bottom of the second-stage movable fork is slidably installed in the second movable slide groove, a secondary preset groove is concavely provided on the bottom surface of the second-stage movable fork, and a clamping block is provided at the inner end of the secondary preset groove.

[0009] As a further improvement of the present invention, the first drive motor is installed at the inner end of the bottom surface of one of the fixed forks, and the second drive motor is installed at the outer end of the bottom surface of the other fixed fork. The first synchronous transmission element includes a first synchronous transmission shaft and two second rotating gears. One end of the first synchronous transmission shaft is rotatably installed in the first rotating hole of one of the fixed forks, and the other end of the first synchronous transmission shaft is rotatably installed in the first rotating hole of the other fixed fork. A first linkage wheel is provided at one end of the first synchronous transmission shaft, and a first transmission belt is sleeved between the first linkage wheel and the output shaft of the first drive motor to realize transmission connection. The two second rotating gears are respectively installed at both ends of the first synchronous transmission shaft, and the two second rotating gears are respectively meshed and connected with the first rotating gears located at the inner ends of the two fixed forks.

[0010] As a further improvement of the present invention, the second synchronous transmission element includes a second synchronous transmission shaft and two third transmission wheels, one end of the second synchronous transmission shaft is installed in the second rotating hole of one of the fixed forks, and the other end of the second synchronous transmission shaft is installed in the second rotating hole of the other fixed fork, and a second linkage wheel is provided at one end of the second synchronous transmission shaft, and a second transmission belt is sleeved between the second linkage wheel and the output shaft of the second drive motor to realize transmission connection, the two third transmission wheels are respectively installed at both ends of the second synchronous transmission shaft, and a third transmission belt is sleeved between the third transmission wheel, the two secondary transmission wheels and the two tertiary transmission wheels to realize transmission connection, and the clamping block is installed on the third transmission belt.

[0011] The present invention also relates to an electric drive system, comprising an electric wheel loader frame, a right front wheel drive axle structure assembly, a hydraulic valve group, a hydraulic pump motor, a hydraulic accumulator group, a right rear wheel drive axle structure assembly, a left rear wheel drive axle structure assembly, a hydraulic oil tank and a left front wheel drive axle structure assembly, wherein the right front wheel drive axle structure assembly, the hydraulic valve group, the hydraulic pump motor, the hydraulic accumulator group, the right rear wheel drive axle structure assembly, the left rear wheel drive axle structure assembly, the hydraulic oil tank and the left front wheel drive axle structure assembly are all installed in the electric wheel loader frame, and the right front wheel drive axle structure assembly, the hydraulic valve group, the hydraulic pump motor, the hydraulic accumulator group, the right rear wheel drive axle structure assembly, the left rear wheel drive axle structure assembly The structural assembly, the hydraulic oil tank and the left front wheel drive axle structural assembly are interconnected through hydraulic pipelines. The right front wheel drive axle structural assembly, the right rear wheel drive axle structural assembly, the left rear wheel drive axle structural assembly and the left front wheel drive axle structural assembly are connected to the electric wheel loader frame through a mechanical structure. The two adjusting hydraulic cylinders are connected to the hydraulic valve group through hydraulic pipelines respectively; the right front wheel drive axle structural assembly, the right rear wheel drive axle structural assembly, the left rear wheel drive axle structural assembly and the left front wheel drive axle structural assembly are all composed of a four-quadrant hydraulic pump motor and a drive axle. The four-quadrant hydraulic pump motor is used to provide driving power. The drive axle includes a main reducer, a wheel-side reducer, a clutch, a brake and an input shaft.

[0012] As a further improvement of the present invention, a steering brake mechanism is arranged in the frame of the electric wheel loader, and the steering brake mechanism includes a steering system, a driving mechanical brake system and a parking brake system.

[0013] As a further improvement of the present invention, the hydraulic accumulator group includes a first hydraulic accumulator and a second hydraulic accumulator. The four-quadrant hydraulic pump motors of the first hydraulic accumulator, the right front wheel drive axle structure assembly, the right rear wheel drive axle structure assembly, the left rear wheel drive axle structure assembly and the left front wheel drive axle structure assembly are respectively connected to the hydraulic valve group through hydraulic pipelines, so that the hydraulic valve group can individually control the four four-quadrant hydraulic pump motors. A priority valve is arranged in the hydraulic valve group, and the priority valve is respectively connected to the steering brake mechanism and the second hydraulic accumulator through hydraulic pipelines.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. The present invention improves the transmission efficiency of the traditional electric drive system and reduces the energy loss caused by low efficiency by utilizing the cooperation of the hydraulic pump motor, hydraulic valve group, hydraulic accumulator group and four four-quadrant hydraulic pump motors. It also utilizes the characteristic that the four-quadrant hydraulic pump motors in parallel in the electric drive system can operate relatively independently. When applied to electric forklifts, the vehicle body layout is more flexible and reasonable, the environmental adaptability is enhanced, the control method is more flexible, and the utilization efficiency of ground adhesion conditions can be effectively enhanced, thereby improving the vehicle handling stability. In addition, by utilizing the characteristics of the four-quadrant operation of the four-quadrant hydraulic pump motor, the kinetic energy of the system during braking can be recovered and stored for reuse.

[0016] 2. The present invention can accurately adjust the length and angle of the fork assembly to achieve precise positioning and stable handling, reduce the risk of shaking and sliding of goods during handling, reduce the safety hazards caused by unstable goods through the cooperation of the hydraulic system and the cylinder, and can effectively and quickly adjust the length of the fork to adapt to goods of different sizes, thereby improving the flexibility and applicability of handling, improving the operating efficiency and safety of the forklift, and making the cargo handling process more efficient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a top view of the electric drive system in the present invention.

[0018] Figure 2 It is a bottom view of the electric drive system of the present invention.

[0019] Figure 3 The figure is a flow chart of the hydraulic pipeline of the electric drive system in the present invention.

[0020] Figure 4 It is a three-dimensional schematic diagram of the electric forklift in the present invention.

[0021] Figure 5 It is a schematic diagram of the interior of the electric forklift in the present invention.

[0022] Figure 6 It is a rear side view of a fork assembly in one embodiment of the present invention.

[0023] Figure 7 It is a front side view of a fork assembly in one embodiment of the present invention.

[0024] Figure 8 Schematic diagram of the interior of a fork assembly in one embodiment of the present invention.

[0025] Fig. 9FIG. 4 is an internal schematic diagram of a fork assembly in another embodiment of the present invention.

[0026] In the figure:

[0027] 10. Electric wheel loader frame; 11. Right front wheel drive axle structure assembly; 12. Hydraulic valve group; 13. Hydraulic pump motor; 14. Hydraulic accumulator group; 15. Right rear wheel drive axle structure assembly; 16. Left rear wheel drive axle structure assembly; 17. Hydraulic oil tank; 18. Left front wheel drive axle structure assembly; 20. Four-quadrant hydraulic pump motor; 21. Drive axle; 41. Steering system; 42. Driving mechanical brake system; 43. Parking brake system; 141, first hydraulic accumulator; 140, second hydraulic accumulator; 30, priority valve; 50, forklift body; 51, hollow cavity; 52, preset groove; 53, adjustment hydraulic cylinder; 54, hydraulic adjustment shaft; 55, adjustment connecting plate; 60, connection adjustment assembly; 61, connection adjustment frame; 62, vertical adjustment cylinder; 63, fork vertical mounting frame; 64, connection mounting frame; 611, connection mounting cross plate; 612, adjustment Install the turntable; 613, connect the installation turntable; 614, vertical installation slide; 70, fork assembly; 71, fork element; 72, first drive motor; 73, second drive motor; 74, first synchronous transmission element; 75, second synchronous transmission element; 711, fixed fork; 712, first mobile fork; 713, second mobile fork; 714, transmission cavity; 715, first rotating hole; 716, second rotating hole; 717, transmission shaft; 718, first rotating gear; 719, first mobile slide; 761, connecting groove; 762, transmission installation groove; 763, second transmission shaft; 764, second transmission wheel; 765, second mobile slide; 767, second preset groove; 741, first synchronous transmission shaft; 742, second rotating gear; 743, first linkage wheel; 751, second synchronous transmission shaft; 752, third transmission wheel; 753, second linkage wheel. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0029] In the description of the present invention, it should be noted that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0031] See also Figures 4 to 9 An electric forklift includes a forklift body 50, a connection adjustment component 60 and a fork assembly 70, wherein the connection adjustment component 60 is installed on the outside of the forklift body 50, and the fork assembly 70 is installed on the bottom of the connection adjustment component 60.

[0032] A hollow cavity 51 is provided inside the forklift body 50, and preset grooves 52 are respectively recessed at both ends of the outer bottom of the hollow cavity 51, and adjusting hydraulic cylinders 53 are rotatably provided on both sides of the bottom surface of the hollow cavity 51. The output shaft of the adjusting hydraulic cylinder 53 passes through the preset groove 52 and protrudes outside the forklift body 50. A hydraulic adjustment shaft 54 ​​is rotatably provided at the outer bottom of the forklift body 50, and adjusting connecting plates 55 are respectively provided at both ends of the hydraulic adjustment shaft 54.

[0033] The connection adjustment assembly 60 includes a connection adjustment frame 61, two vertical adjustment cylinders 62, a fork vertical mounting frame 63 and a connection mounting frame 64. A connection mounting horizontal plate 611 is convexly provided at the bottom of the inner side of the connection adjustment frame 61. Adjustment mounting turntables 612 are convexly provided at both ends of the inner side of the connection mounting horizontal plate 611. The two adjustment mounting turntables 612 are respectively rotatably connected to the outer sides of the two adjustment connection plates 55. A mounting cavity is concavely provided at the inner side of the connection adjustment frame 61. Vertical mounting slide grooves 614 are concavely provided at both ends of the mounting cavity. A connecting and mounting turntable 613 is protruded from the middle of both ends, and the two connecting and mounting turntables 613 are respectively rotatably connected to the output shafts of the two adjusting hydraulic cylinders 53, and the bottom ends of the two vertical adjusting cylinders 62 are respectively mounted on the two ends of the inner top of the connecting and mounting horizontal plate 611, and the two ends of the fork vertical mounting frame 63 are respectively slidably mounted in the two vertical mounting slide grooves 614, and the two ends of the inner top of the fork vertical mounting frame 63 are respectively connected to the top ends of the two vertical adjusting cylinders 62, and the connecting and mounting frame 64 is mounted on the outer bottom of the fork vertical mounting frame 63.

[0034] The fork assembly 70 includes two fork elements 71, a first drive motor 72, a second drive motor 73, a first synchronous transmission element 74 and a second synchronous transmission element 75. The inner ends of the two fork elements 71 are respectively mounted on the two ends of the outer bottom of the connecting mounting frame 64, the first drive motor 72 and the second drive motor 73 are respectively mounted on the bottom of the two fork elements 71, and the first drive motor 72 and the second drive motor 73 are staggered. The first synchronous transmission element 74 is installed in the two fork elements 71, and the second synchronous transmission element 75 is installed in the two fork elements 71.

[0035] Each fork element 71 includes a fixed fork 711, a primary movable fork 712 and a secondary movable fork 713. The inner end of the fixed fork 711 is mounted on one end of the bottom of the outer side of the connecting mounting frame 64. The fixed fork 711 is hollow inside to form a transmission cavity 714. The inner ends of the transmission cavity 714 are respectively recessed with first rotating holes 715. The outer ends of the transmission cavity 714 are respectively recessed with second rotating holes 716. The middle part of the transmission cavity 714 is provided with a plurality of transmission shafts 717 along the length direction. Each transmission shaft 717 is provided with a first rotating gear 718, and the plurality of first rotating gears 718 are meshed and connected with each other. The top of the transmission cavity 714 is recessed with a first movable slide groove 719. The bottom of the primary movable fork 712 is slidably mounted in the first movable slide groove 719. A connecting groove 761 is recessed on the bottom surface of the first-stage movable fork 712, and a spur rack is protruding on the top surface of the connecting groove 761, which is meshed and connected with a plurality of first rotating gears 718. Transmission mounting grooves 762 are recessed in the middle of both ends of the connecting groove 761, and a secondary transmission shaft 763 is rotatably arranged in the transmission mounting groove 762, and a secondary transmission wheel 764 is arranged in the middle of the secondary transmission shaft 763. A second movable slide groove 765 is recessed on the top surface of the first-stage movable fork 712, and lifting seats are respectively protruding at both ends of the top surface of the second movable slide groove 765, and a third-stage transmission wheel is rotatably arranged on the top of each lifting seat, and the bottom of the second-stage movable fork 713 is slidably installed in the second movable slide groove 765, and a secondary preset groove 767 is recessed on the bottom surface of the second-stage movable fork 713, and a clamping block is arranged at the inner end of the secondary preset groove 767.

[0036] The first drive motor 72 is installed at the inner end of the bottom surface of one of the fixed forks 711, and the second drive motor 73 is installed at the outer end of the bottom surface of the other fixed fork 711. The first synchronous transmission element 74 includes a first synchronous transmission shaft 741 and two second rotating gears 742. One end of the first synchronous transmission shaft 741 is rotatably installed in the first rotating hole 715 of one of the fixed forks 711, and the other end of the first synchronous transmission shaft 741 is rotatably installed in the first rotating hole 715 of the other fixed fork 711. A first interlocking wheel 743 is provided at one end of the first synchronous transmission shaft 741. A first transmission belt is sleeved between the first interlocking wheel 743 and the output shaft of the first drive motor 72 to achieve transmission connection. The two second rotating gears 742 are respectively installed at both ends of the first synchronous transmission shaft 741, and the two second rotating gears 742 are respectively meshed and connected with the first rotating gears 718 located at the inner ends of the two fixed forks 711.

[0037] The second synchronous transmission element 75 includes a second synchronous transmission shaft 751 and two third transmission wheels 752. One end of the second synchronous transmission shaft 751 is installed in the second rotating hole 716 of one of the fixed forks 711, and the other end of the second synchronous transmission shaft 751 is installed in the second rotating hole 716 of the other fixed fork 711. A second interlocking wheel 753 is provided at one end of the second synchronous transmission shaft 751. A second transmission belt is sleeved between the second interlocking wheel 753 and the output shaft of the second drive motor 73 to achieve transmission connection. The two third transmission wheels 752 are respectively installed at both ends of the second synchronous transmission shaft 751, and a third transmission belt is sleeved between the third transmission wheel 752, the two secondary transmission wheels 764 and the two tertiary transmission wheels to achieve transmission connection, and the clamping block is mounted on the third transmission belt.

[0038] See also Figures 1 to 3The present invention also relates to an electric drive system, comprising an electric wheel loader frame 10, a right front wheel drive axle structure assembly 11, a hydraulic valve group 12, a hydraulic pump motor 13, a hydraulic accumulator group 14, a right rear wheel drive axle structure assembly 15, a left rear wheel drive axle structure assembly 16, a hydraulic oil tank 17 and a left front wheel drive axle structure assembly 18, wherein the right front wheel drive axle structure assembly 11, the hydraulic valve group 12, the hydraulic pump motor 13, the hydraulic accumulator group 14, the right rear wheel drive axle structure assembly 15, the left rear wheel drive axle structure assembly 16, the hydraulic oil tank 17 and the left front wheel drive axle structure assembly 18 are all installed on the electric wheel loader. In the loader frame 10, the right front wheel drive axle structure assembly 11, the hydraulic valve group 12, the hydraulic pump motor 13, the hydraulic accumulator group 14, the right rear wheel drive axle structure assembly 15, the left rear wheel drive axle structure assembly 16, the hydraulic oil tank 17 and the left front wheel drive axle structure assembly 18 are connected to each other through hydraulic pipelines, the right front wheel drive axle structure assembly 11, the right rear wheel drive axle structure assembly 15, the left rear wheel drive axle structure assembly 16 and the left front wheel drive axle structure assembly 18 are connected to the electric wheel loader frame 10 through a mechanical structure, and the two adjusting hydraulic cylinders 53 are connected to the hydraulic valve group 12 through hydraulic pipelines respectively;

[0039] The right front wheel drive axle structure assembly 11, the right rear wheel drive axle structure assembly 15, the left rear wheel drive axle structure assembly 16 and the left front wheel drive axle structure assembly 18 are all composed of a four-quadrant hydraulic pump motor 20 and a drive axle 21. The four-quadrant hydraulic pump motor 20 is used to provide driving power, and the drive axle 21 includes a main reducer, a wheel-side reducer, a clutch, a brake and an input shaft.

[0040] A steering brake mechanism is provided in the electric wheel loader frame 10 , and the steering brake mechanism includes a steering system 41 , a driving mechanical brake system 42 and a parking brake system 43 .

[0041] The four-quadrant hydraulic pump-motor 20 of the right front wheel drive axle structure assembly 11, the right rear wheel drive axle structure assembly 15, the left rear wheel drive axle structure assembly 16 and the left front wheel drive axle structure assembly 18 are respectively connected to the hydraulic valve group 12 through hydraulic pipelines, so that the hydraulic valve group 12 can individually control the four four-quadrant hydraulic pump-motor 20. A priority valve 30 is arranged in the hydraulic valve group 12, and the priority valve 30 is connected to the steering brake mechanism through a hydraulic pipeline.

[0042] For example, in one embodiment: the four-quadrant hydraulic pump motor 20 has the function of four-quadrant operation, and can act as both a driving mechanism and an energy recovery mechanism to recover braking energy.

[0043] For example, in one embodiment: when the electric forklift is started to move forward or backward, the hydraulic pump motor 13 will be started, and the hydraulic valve group 12 will be used to distribute power to the four four-quadrant hydraulic pump motors 20, and then the drive axle 21 will transmit power to the tires to move forward or backward.

[0044] When the vehicle needs to brake to stop, the hydraulic pump motor 13 will stop outputting hydraulic power, so that the four four-quadrant hydraulic pump motors 20 will switch to the pump mode, and a part of the braking energy will be recovered to the first hydraulic accumulator 141. When energy output is required next time, the first hydraulic accumulator 141 can provide the hydraulic valve group 12 to release hydraulic power to drive the four four-quadrant hydraulic pump motors 20 to work.

[0045] For example, in one embodiment: during the braking process of the vehicle, when each of the four-quadrant hydraulic pump motors 20 cannot meet the braking demand, the hydraulic pump motor 13 will provide hydraulic energy to the brake through the priority valve 30, so that the brake can provide a part of the walking mechanical braking to participate in the vehicle braking, ensuring the safety of the vehicle during driving. At the same time, the hydraulic pump motor 13 will provide hydraulic energy to the steering system 41 through the priority valve 30, allowing it to control the steering of the vehicle, and then use the priority valve 30 to ensure that the output power of the hydraulic pump motor 13 is preferentially supplied to the steering system 41 and the brake to avoid dangerous situations.

[0046] For example, in one embodiment: when the hydraulic energy provided by the hydraulic pump motor 13 is lost due to an emergency failure of the vehicle, the second hydraulic accumulator 140 will be started and the stored hydraulic power will be directly input into the steering and braking mechanism to ensure that there is sufficient hydraulic energy for vehicle steering and braking.

[0047] For example, in one embodiment: when the vehicle turns, the differential speed and torque between each wheel can be guaranteed by controlling the hydraulic valve group 12 to output different hydraulic energies and controlling the different displacements of each four-quadrant hydraulic pump motor 20, so as to ensure that the electric forklift does not slip during normal driving and operation, resulting in the generation of large parasitic power and energy loss.

[0048] In summary, the present invention improves the transmission efficiency of the electric drive system and reduces the energy loss caused by low efficiency by utilizing the cooperation of the hydraulic pump motor 13, the hydraulic valve group 12, the hydraulic accumulator group 14 and the four four-quadrant hydraulic pump motors 20, and utilizes the characteristic that the four-quadrant hydraulic pump motors 20 connected in parallel in the electric drive system can operate relatively independently. When applied to electric forklifts, the body layout is more flexible and reasonable, the environmental adaptability is enhanced, the control method is more flexible, and the utilization efficiency of the ground adhesion conditions can be effectively enhanced, and the vehicle handling stability is improved. In addition, by utilizing the characteristics of the four-quadrant operation of the four-quadrant hydraulic pump motor 20, the kinetic energy during the braking of the system can be recovered and stored for reuse.

[0049] For example, in one embodiment: when adjustment is required according to the length of the cargo, the first drive motor 72 is started first, and the power is transmitted to the first linkage wheel 743 by using the first transmission belt, so that the first synchronous transmission shaft 741 rotates, and the two second rotating gears 742 rotate accordingly, so that the multiple first rotating gears 718 in the two fixed forks 711 rotate accordingly, and because the spur rack is meshed and connected with the multiple first rotating gears 718, the primary movable fork 712 is moved along the first movable slide groove 719, thereby adjusting the length of the fork element 71.

[0050] When the length of the fork element 71 still needs to be increased, the second drive motor 73 will be started to rotate the second synchronous transmission shaft 751, so that the two third transmission wheels 752 rotate accordingly, and then the third transmission belt moves accordingly, and then the clamping block moves accordingly, and then the secondary movable fork 713 moves along the second movable slide groove 765, and then the length of the fork element 71 is further adjusted to ensure that it can adapt to various cargo lengths for handling operations.

[0051] When the goods need to be transported and moved, the two vertical adjustment cylinders 62 will be started, so that the fork vertical mounting frame 63 and the connecting mounting frame 64 will move up and down along the vertical mounting slide groove 614, and then the goods will be lifted. At the same time, the hydraulic valve group 12 will transmit hydraulic pressure to the two adjusting hydraulic cylinders 53 and the hydraulic adjusting shaft 54, so that the output shaft of the adjusting hydraulic cylinder 53 extends / retracts, and the hydraulic adjusting shaft 54 ​​rotates, so that the adjusting connecting plate 55 follows the movement. Since the two adjusting mounting turntables 612 at the bottom of the connecting adjustment frame 61 are respectively rotatably connected to the outer sides of the two adjusting connecting plates 55, the connecting adjustment frame 61 is tilted and moved, so that the fork assembly 70 follows the displacement and tilts, so that the goods tilt inward, thereby realizing precise control of the fork assembly 70 and ensuring the stability of the goods when the electric forklift moves.

[0052] Installation process: an electric drive system is installed in the forklift body 50, two adjustment mounting turntables 612 are respectively rotatably connected to the outer sides of the two adjustment connecting plates 55, two connecting mounting turntables 613 are respectively rotatably connected to the output shafts of the two adjusting hydraulic cylinders 53, the bottom ends of the two vertical adjustment cylinders 62 are respectively installed at the two ends of the inner top of the connecting mounting cross plate 611, the two ends of the fork vertical mounting frame 63 are respectively slidably installed in the two vertical mounting slide grooves 614, and the two ends of the inner top of the fork vertical mounting frame 63 are respectively connected to the tops of the two vertical adjustment cylinders 62, the connecting mounting frame 64 is installed at the outer bottom of the fork vertical mounting frame 63, the inner end of the fixed fork 711 is installed at one end of the outer bottom of the connecting mounting frame 64, the bottom of the first-level moving fork 712 is slidably installed in the first moving slide groove 719, the bottom of the second-level moving fork 713 is slidably installed in the second moving slide groove 765, and the first drive motor 72 is installed in one of the fixed The inner end of the bottom surface of the fixed fork 711, the second drive motor 73 is installed at the outer end of the bottom surface of the other fixed fork 711, one end of the first synchronous transmission shaft 741 is rotatably installed in the first rotating hole 715 of one of the fixed forks 711, and the other end of the first synchronous transmission shaft 741 is rotatably installed in the first rotating hole 715 of the other fixed fork 711, two second rotating gears 742 are respectively installed at both ends of the first synchronous transmission shaft 741, and the two second rotating gears 742 are respectively meshed and connected with the first rotating gears 718 located at the inner ends of the two fixed forks 711, one end of the second synchronous transmission shaft 751 is installed in the second rotating hole 716 of one of the fixed forks 711, and the other end of the second synchronous transmission shaft 751 is installed in the second rotating hole 716 of the other fixed fork 711, two third transmission wheels 752 are respectively installed at both ends of the second synchronous transmission shaft 751, and the clamping block is installed on the third transmission belt.

[0053] The present invention can achieve:

[0054] 1. The present invention improves the transmission efficiency of the traditional electric drive system and reduces the energy loss caused by low efficiency by utilizing the cooperation of the hydraulic pump motor 13, the hydraulic valve group 12, the hydraulic accumulator group 14 and the four four-quadrant hydraulic pump motors 20. The present invention also utilizes the characteristics of the four-quadrant hydraulic pump motors 20 in parallel in the electric drive system being able to operate relatively independently. When applied to electric forklifts, the vehicle body layout is more flexible and reasonable, the environmental adaptability is enhanced, the control method is more flexible, and the utilization efficiency of the ground adhesion conditions is effectively enhanced, thereby improving the vehicle handling stability. In addition, by utilizing the characteristics of the four-quadrant operation of the four-quadrant hydraulic pump motor 20, the kinetic energy of the system during braking can be recovered and stored for reuse.

[0055] 2. The present invention can accurately adjust the length and angle of the fork assembly 70 to achieve precise positioning and stable transportation, reduce the risk of shaking and sliding of goods during transportation, and reduce the safety hazards caused by unstable goods through the cooperation of the hydraulic system and the cylinder. It can also effectively and quickly adjust the length of the fork to adapt to goods of different sizes, thereby improving the flexibility and applicability of transportation, improving the operating efficiency and safety of the forklift, and making the cargo handling process more efficient and reliable.

[0056] The above-mentioned embodiments only express several embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An electric forklift, characterized in that: It comprises a forklift body (50), a connection adjustment assembly (60) and a fork assembly (70), wherein the connection adjustment assembly (60) is mounted on the outside of the forklift body (50), and the fork assembly (70) is mounted on the bottom of the connection adjustment assembly (60); A hollow cavity (51) is provided inside the forklift body (50), and preset grooves (52) are respectively provided at both ends of the outer bottom of the hollow cavity (51), and adjustable hydraulic cylinders (53) are rotatably provided on both sides of the bottom of the hollow cavity (51), and the output shaft of the adjustable hydraulic cylinder (53) passes through the preset groove (52) and is convexly provided outside the forklift body (50), and a hydraulic adjustment shaft (54) is rotatably provided at the outer bottom of the forklift body (50), and adjustable connecting plates (55) are respectively provided at both ends of the hydraulic adjustment shaft (54); The connection adjustment assembly (60) comprises a connection adjustment frame (61), two vertical adjustment cylinders (62), a fork vertical mounting frame (63) and a connection mounting frame (64). A connection mounting horizontal plate (611) is convexly provided at the bottom of the inner side of the connection adjustment frame (61). Adjustment mounting turntables (612) are convexly provided at both ends of the inner side of the connection mounting horizontal plate (611). The two adjustment mounting turntables (612) are respectively rotatably connected to the outer sides of the two adjustment connection plates (55). A mounting cavity is concavely provided at the inner side of the connection adjustment frame (61). Vertical mounting slide grooves (614) are concavely provided at both ends of the mounting cavity. A connecting and mounting turntable (613) is protruded at the middle of both ends of the fork (61), and the two connecting and mounting turntables (613) are respectively rotatably connected to the output shafts of the two adjusting hydraulic cylinders (53). The bottom ends of the two vertical adjusting cylinders (62) are respectively mounted on the two ends of the inner top of the connecting and mounting cross plate (611). The two ends of the fork vertical mounting frame (63) are respectively slidably mounted in the two vertical mounting slide grooves (614), and the two ends of the inner top of the fork vertical mounting frame (63) are respectively connected to the top ends of the two vertical adjusting cylinders (62). The connecting and mounting frame (64) is mounted on the outer bottom of the fork vertical mounting frame (63); The fork assembly (70) comprises two fork elements (71), a first drive motor (72), a second drive motor (73), a first synchronous transmission element (74) and a second synchronous transmission element (75); the inner ends of the two fork elements (71) are respectively mounted on the two ends of the outer bottom of the connecting mounting frame (64); the first drive motor (72) and the second drive motor (73) are respectively mounted on the bottom of the two fork elements (71); the first drive motor (72) and the second drive motor (73) are arranged in an alternating manner; the first synchronous transmission element (74) is mounted in the two fork elements (71); and the second synchronous transmission element (75) is mounted in the two fork elements (71); Each fork element (71) comprises a fixed fork (711), a first-stage movable fork (712) and a second-stage movable fork (713). The inner end of the fixed fork (711) is mounted on one end of the outer bottom of the connecting mounting frame (64). The fixed fork (711) is hollow inside to form a transmission cavity (714). First rotation holes (715) are respectively recessed on both sides of the inner end of the transmission cavity (714). Second rotation holes (716) are respectively recessed on both sides of the outer end of the transmission cavity (714). A plurality of transmission shafts (717) are arranged in the middle of the transmission cavity (714) along the length direction. Each transmission shaft (717) is provided with a first rotating gear (718), and the plurality of first rotating gears (718) are meshed and connected with each other. A first movable slide groove (719) is recessed on the top of the transmission cavity (714). The bottom of the first-stage movable fork (712) is slidably mounted on the first movable slide groove (719). ), a connecting groove (761) is concavely provided on the bottom surface of the first movable fork (712), a spur rack is convexly provided on the top surface of the connecting groove (761), the spur rack is meshingly connected with a plurality of first rotating gears (718), transmission installation grooves (762) are respectively concavely provided in the middle of both ends of the connecting groove (761), a secondary transmission shaft (763) is rotatably provided in the transmission installation groove (762), a secondary transmission wheel (764) is provided in the middle of the secondary transmission shaft (763), a second movable slide groove (765) is concavely provided on the top surface of the first movable fork (712), lifting seats are respectively convexly provided on the top ends of the second movable slide groove (765), a third-stage transmission wheel is rotatably provided on the top of each lifting seat, the bottom of the second movable fork (713) is slidably installed in the second movable slide groove (765), a secondary preset groove (767) is concavely provided on the bottom surface of the second movable fork (713), and a clamping block is provided at the inner end of the secondary preset groove (767); The first drive motor (72) is mounted on the inner end of the bottom surface of one of the fixed forks (711), the second drive motor (73) is mounted on the outer end of the bottom surface of the other fixed fork (711), the first synchronous transmission element (74) comprises a first synchronous transmission shaft (741) and two second rotating gears (742), one end of the first synchronous transmission shaft (741) is rotatably mounted in a first rotating hole (715) of one of the fixed forks (711), and the other end of the first synchronous transmission shaft (741) is rotatably mounted on the other fixed fork (711), and a first linkage wheel (743) is arranged at one end of the first synchronous transmission shaft (741), a first transmission belt is sleeved between the first linkage wheel (743) and the output shaft of the first drive motor (72) to achieve transmission connection, two second rotating gears (742) are respectively installed at both ends of the first synchronous transmission shaft (741), and the two second rotating gears (742) are respectively meshed and connected with the first rotating gears (718) located at the inner ends of the two fixed forks (711); The second synchronous transmission element (75) comprises a second synchronous transmission shaft (751) and two third transmission wheels (752); one end of the second synchronous transmission shaft (751) is mounted in a second rotating hole (716) of one of the fixed forks (711); the other end of the second synchronous transmission shaft (751) is mounted in a second rotating hole (716) of the other fixed fork (711); a second linkage wheel (753) is arranged at one end of the second synchronous transmission shaft (751); a second transmission belt is sleeved between the second linkage wheel (753) and an output shaft of the second drive motor (73) to achieve transmission connection; the two third transmission wheels (752) are respectively mounted at two ends of the second synchronous transmission shaft (751); a third transmission belt is sleeved between the third transmission wheel (752), the two secondary transmission wheels (764) and the two tertiary transmission wheels to achieve transmission connection; and the clamping block is mounted on the third transmission belt.

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