Pure electric stacking type forklift

Abstract

The invention relates to the technical field of forklifts, and particularly discloses a pure electric stacking type forklift which comprises a forklift body and fork heads, an electric driving unit is installed on the forklift body and comprises a motor and a speed reducer, the speed reducer is installed on the forklift body, and the motor is connected with the speed reducer. The electric driving unit is connected with the lifting unit so as to drive the fork head to ascend, electric driving is adopted to replace a hydraulic system, and the problems existing in the hydraulic system are avoided. The method has the advantages that firstly, no hydraulic system exists, no oil leakage risk exists, and the method is more environment-friendly; secondly, positioning control and speed control are more accurate, response is faster, and influence of environment temperature is avoided; hydraulic impact is avoided, noise is low, and operation is more stable; then, no hydraulic loop loss exists, the energy efficiency is high, and more energy is saved; and finally, hydraulic oil, sealing elements and the like do not need to be replaced regularly, using and maintaining are easy, and manufacturing and maintaining cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of forklifts, and in particular relates to a pure electric stacking forklift. Background Art

[0002] With the development of the logistics industry, forklifts have become more diversified, and various types of forklifts have emerged one after another. However, fundamentally, forklifts with high-position lifting still use hydraulic systems as lifting power systems and hydraulic cylinders as lifting actuators.

[0003] Specifically, the forklift is equipped with an oil tank, a pump motor, an oil pump, a single-acting oil cylinder and some hydraulic accessories. The pump motor drives the oil pump to rotate, converting the hydraulic oil in the hydraulic oil tank into pressure oil and transporting it to the single-acting oil cylinder. The oil cylinder lifts up the mast or the fork frame with forks installed. When descending, it falls by the deadweight of the mast and the fork frame with forks installed. There are many types of masts, such as single mast, two-stage mast, and three-stage mast.

[0004] Hydraulic system technology is mature, stable and reliable, but as industry requirements become increasingly sophisticated, its disadvantages are beginning to emerge in certain scenarios. For example, in food and pharmaceutical warehouses, which have very high requirements for cleanliness, hydraulic oil leakage can have a significant impact.

[0005] First, the positioning accuracy of the hydraulic system is insufficient. For example, the precise positioning of the lifting height needs to rely on the control of an external pull-wire encoder, but the response of the hydraulic system itself will cause insufficient positioning accuracy. The hydraulic drive is complex and costly; the energy conversion loss is large and the energy consumption is high.

[0006] In addition, the thermal stability of the hydraulic system is poor. Because the hydraulic medium - hydraulic oil is sensitive to temperature, the lifting and lowering performance of the forklift is greatly affected by the environment. When the temperature changes greatly, the lifting and lowering speed changes greatly. The thermal expansion and contraction effect of the hydraulic oil causes the hydraulic oil to cool after the hot car is stationary, and the fork will slide down to a certain extent, which has a greater impact on some automated vehicles. Therefore, this application proposes a pure electric stacking forklift. Summary of the invention

[0007] The object of the present invention is to provide a pure electric stacking forklift to solve the problems raised by the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a pure electric stacking forklift, comprising a body and a fork head, wherein an electric drive unit is mounted on the body, the electric drive unit comprises a motor and a reducer, the reducer is mounted on the body, and the motor is connected to the reducer;

[0009] The output shaft of the motor is connected to the brake, and the brake is turned on to lock the output shaft of the motor;

[0010] An encoder for measuring the number of rotations of the motor is arranged on the output shaft of the motor;

[0011] An outer mast is fixedly mounted on the vehicle body, and the inner mast can roll up and down through rollers and a first roller track in the outer mast, and the fork is connected to the inner mast;

[0012] The electric drive unit is connected to the lifting unit, and the electric drive unit drives the inner mast and the fork to lift and lower through the lifting unit.

[0013] Preferably, one end of the output shaft of the motor is spline-connected to the reducer, and the other end is spline-connected to the brake.

[0014] Preferably, the lifting unit includes a driving sprocket, and the two output shafts in the reducer are connected to the driving sprocket through a flat key, and the fork head can roll up and down through a roller and a second raceway in the inner door frame.

[0015] Preferably, an upper sprocket assembly is fixed above the outer door frame, and a lower sprocket assembly is fixed below the outer door frame. The roller chain passes around the drive sprocket, the upper sprocket assembly, and the lower sprocket assembly. The beginning and end of the roller chain are fixed on the upper and lower sides of the chain plate inside the inner door frame.

[0016] Preferably, the chain plate is fixed to the inner door frame by welding, two roller chains are provided, and the two roller chains are respectively connected to two driving sprockets.

[0017] Preferably, a fork lifting chain hole is provided on the fork, and an outer mast lifting chain hole is provided on the outer mast.

[0018] Preferably, an inner mast sprocket is installed on the inner mast, and a lifting plate chain is connected to the inner mast sprocket, one end of which is fixed at the lifting chain hole of the outer mast, and the other end is fixed at the lifting chain hole of the fork.

[0019] Preferably, the upper sprocket assembly comprises a sprocket body, an intermediate shaft is inserted into the sprocket body, and the intermediate shaft is connected to the sprocket body through a bearing.

[0020] Preferably, both ends of the intermediate shaft are respectively inserted into two brackets, and a bolt is inserted into each of the brackets.

[0021] Preferably, the lifting unit includes a drum with a steel wire rope wound around it, the two drums are respectively connected to the two output shafts of the reducer through a flat key, and the other end of the steel wire rope is connected to the inner door frame.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention connects the lifting unit through the electric drive unit to drive the fork head to rise, and adopts electric drive instead of hydraulic system to avoid the problems of hydraulic system. There are the following advantages: first, there is no hydraulic system, no risk of oil leakage, and more environmentally friendly; second, the positioning control and speed control are more accurate, the response is faster, and it is not affected by the ambient temperature; then, there is no hydraulic shock and the operation is smoother; then, there is no hydraulic circuit loss, high energy efficiency, and more energy saving; finally, there is no need to regularly replace hydraulic oil and seals, etc., and the use and maintenance are simple.

[0024] 2. The power assembly for controlling the rise and fall of the fork of the present invention adopts an electric drive unit, which is integrally arranged on the vehicle body, has a compact structure, and is easy to observe and maintain. The fork is driven to rise and fall by electric drive plus sprockets and chains. The daily wear and tear during use is very small, and the maintenance frequency is very low.

[0025] 3. The present invention realizes the rising and falling of the fork head through roller chains and lifting plate chains. When the chain transmission is in use, the elongation of the chain itself can be ignored, and the height control of the rising and falling is more precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of a pure electric stacking forklift in Embodiment 1 of the present invention.

[0027] Figure 2 This is a disassembled diagram of the pure electric stacking forklift in the first embodiment of the present invention.

[0028] Figure 3 Schematic diagram of the structure of the electric drive unit in the first embodiment of the present invention.

[0029] Figure 4 It is a schematic structural diagram of the upper sprocket assembly in the present invention.

[0030] Figure 5 It is a schematic structural diagram of a pure electric stacking forklift in the second embodiment of the present invention.

[0031] Figure 6 This is a disassembled diagram of the pure electric stacking forklift in the second embodiment of the present invention.

[0032] Figure 7 It is a schematic diagram of the structure of the electric drive unit in the second embodiment of the present invention.

[0033] In the figure: 1. body; 11. motor; 12. reducer; 13. drive sprocket; 14. brake; 15. encoder; 16. drum; 2. outer door frame; 21. lifting chain hole of outer door frame; 22. upper sprocket assembly; 221. sprocket body; 222. bearing; 223. intermediate shaft; 224. bracket; 225. bolt; 23. roller chain; 24. lower sprocket assembly; 25. wire rope; 26. guide pulley; 3. inner door frame; 31. chain plate; 32. inner door frame sprocket; 33. lifting plate chain; 4. fork; 41. fork lifting chain hole. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Embodiment 1:

[0036] Reference Figure 1-Figure 4 A pure electric stacking forklift, comprising a body 1 and a fork head 4. The body 1 is equipped with an electric drive unit, the electric drive unit comprising a motor 11 and a reducer 12. The reducer 12 is fixedly mounted on the body 1. The motor 11 is connected to the reducer 12. The output shafts on both sides of the reducer 12 are connected to a driving sprocket 13. Specifically, one end of the output shaft of the motor 11 is spline-connected to the reducer 12, and the other end is spline-connected to the brake 14.

[0037] The power assembly for controlling the rise and fall of the fork 4 adopts an electric drive unit, which is integrally arranged on the vehicle body 1, has a compact structure, and is easy to observe and maintain. The electric drive plus a sprocket and a chain are used to drive the fork 4 to rise and fall. The daily wear and tear during use is very small, and the maintenance and repair frequency is very low;

[0038] The output shaft of the motor 11 is connected to the brake 14, and the brake 14 is turned on to lock the output shaft of the motor 11;

[0039] The output shaft of the motor 11 is provided with an encoder 15 for measuring the number of rotations of the motor 11 , and the rising and falling heights of the fork 4 are measured according to the number of rotations of the output shaft of the motor 11 .

[0040] An outer mast 2 is fixedly mounted on the vehicle body 1, an inner mast 3 can roll up and down through rollers and a first roller track in the outer mast 2, and a fork head 4 can roll up and down through rollers and a second roller track in the inner mast 3;

[0041] The electric drive unit is connected to the lifting unit, and the electric drive unit drives the inner mast 3 and the fork 4 to rise through the lifting unit. The falling of the inner mast 3 and the fork 4 is driven by their own gravity.

[0042] The lifting unit is connected to the electric drive unit to drive the fork 4 to rise. The electric drive eliminates the hydraulic system and avoids the problems of the hydraulic system. There are the following benefits. First, there is no hydraulic system, no oil leakage risk, and it is more environmentally friendly; second, the positioning control and speed control are more accurate, the response is faster, and it is not affected by the ambient temperature; then, there is no hydraulic shock and the operation is smoother; then, there is no hydraulic circuit loss, high energy efficiency, and more energy saving; finally, there is no need to regularly replace hydraulic oil and seals, etc., and the use and maintenance are simple.

[0043] The lifting unit includes a driving sprocket 13, and the two output shafts in the reducer 12 are connected to the driving sprocket 13 through a flat key;

[0044] An upper sprocket assembly 22 is fixed above the outer door frame 2, and a lower sprocket assembly 24 is fixed below the outer door frame 2. The roller chain 23 passes around the drive sprocket 13, the upper sprocket assembly 22, and the lower sprocket assembly 24. The front and rear ends of the roller chain 23 are fixed to the upper and lower sides of the chain plate 31 inside the inner door frame 3. The chain plate 31 is fixed to the inner door frame 3 by welding. It should be noted that two roller chains 23 are provided, and the two roller chains 23 are respectively connected to the two drive sprockets 13.

[0045] A fork lifting chain hole 41 is provided on the fork 4, an outer mast lifting chain hole 21 is provided on the outer mast 2, an inner mast sprocket 32 ​​is installed on the inner mast 3, and a lifting plate chain 33 is connected to the inner mast sprocket 32, one end of which is fixed at the outer mast lifting chain hole 21, and the other end is fixed at the fork lifting chain hole 41.

[0046] By adding a motor 11, a reducer 12 (since the fork head 4 does not need to consider the load of the inner door frame 3, the volume of the motor 11 and the reducer 12 can be made smaller and easier to arrange), a roller chain 23, etc. to the vehicle body 1 and the fork head 4, it can be expanded to a full-free door frame with a wider range of applications.

[0047] The motor 11 is powered and controlled by the vehicle body 1. The motor 11 rotates at high speed, and the speed is reduced and the torque is increased by the reducer 12. The torque is transmitted to the drive sprocket 13, and the drive sprocket 13 rotates at a set speed and provides a large torque. At this time, the roller chain 23 is driven by the drive sprocket 13 to pull the inner mast 3 to lift. The inner mast sprocket 32 ​​on the inner mast 3 acts as a movable pulley. Under the pull of the lifting plate chain 33, the fork head 4 is lifted at twice the speed of the inner mast 3.

[0048] The fork 4 is raised and lowered by the roller chain 23 and the lifting plate chain 33. When the chain transmission is in use, the elongation of the chain itself can be ignored, and the height control of the rise and fall is more precise.

[0049] Correspondingly, when the motor 11 rotates in the reverse direction according to the instruction, the inner mast 3 and the fork head 4 descend under the action of their own weight.

[0050] The fork head 4 can be a three-way fork head 4, which can change the direction of the fork head 4 as needed, and is suitable for the material handling work at narrow roads in factories and warehouses.

[0051] like Figure 4 As shown, the upper sprocket assembly 22 includes a sprocket body 221, an intermediate shaft 223 is inserted into the sprocket body 221, the intermediate shaft 223 is connected to the sprocket body 221 through a bearing 222, and both ends of the intermediate shaft 223 are respectively inserted into two brackets 224, and each of the brackets 224 is inserted with a bolt 225.

[0052] Embodiment 2:

[0053] Reference Figure 4-Figure 7 A pure electric stacking forklift, comprising a body 1 and a fork head 4. The body 1 is provided with an electric drive unit, the electric drive unit comprising a motor 11 and a reducer 12. The reducer 12 is fixedly mounted on the body 1. The motor 11 is connected to the reducer 12. Specifically, one end of the output shaft of the motor 11 is spline-connected to the reducer 12, and the other end is spline-connected to the brake 14.

[0054] The output shaft of the motor 11 is connected to the brake 14, and the brake 14 is turned on to lock the output shaft of the motor 11;

[0055] The output shaft of the motor 11 is provided with an encoder 15 for measuring the number of rotations of the motor 11. The encoder 15 measures the rising and falling heights of the fork 4 according to the number of rotations of the output shaft of the motor 11.

[0056] An outer mast 2 is fixedly mounted on the vehicle body 1, an inner mast 3 can roll up and down through rollers and a first roller track in the outer mast 2, and a fork head 4 can roll up and down through rollers and a second roller track in the inner mast 3;

[0057] The electric drive unit is connected to the lifting unit, and the electric drive unit drives the inner mast 3 and the fork 4 to rise through the lifting unit. The falling of the inner mast 3 and the fork 4 is driven by their own gravity.

[0058] The lifting unit can also adopt the following structure, wherein the lifting unit includes a drum 16, which is connected to the output shaft of the reducer 12. Two drums 16 are provided, and the two drums 16 are respectively connected to the two output shafts of the reducer 12. A wire rope 25 is wound around the drum 16, and the other end of the wire rope 25 passes around the guide pulley 26 to connect to the inner door frame 3. Specifically, the other end of the wire rope 25 is connected to the chain plate 31 in the inner door frame 3. The electric drive unit drives the drum 16 to rotate, thereby winding the wire rope 25 around the outside of the drum 16 or loosening it. The wire rope 25 connected to the drum 16 is wound around it, and the wire rope 25 can pull the inner door frame 3 and the fork head 4 to move upward. When the wire rope 25 is loosened, the inner door frame 3 and the fork head 4 fall under the action of their own gravity.

[0059] A fork lifting chain hole 41 is provided on the fork 4, an outer mast lifting chain hole 21 is provided on the outer mast 2, an inner mast sprocket 32 ​​is installed on the inner mast 3, and a lifting plate chain 33 is connected to the inner mast sprocket 32, one end of which is fixed at the outer mast lifting chain hole 21, and the other end is fixed at the fork lifting chain hole 41.

[0060] When the fork head 4 needs to be moved upward, the motor 11 in the electric drive unit drives the drum 16 to rotate forward, winding the wire rope 25, and the wire rope 25 pulls the inner mast 3 and the fork head 4 upward. During the rising process, the inner mast sprocket 32, the lifting plate chain 33 and other components drive the fork head 4 to be lifted at twice the speed of the inner mast 3, and finally the fork head 4 is raised to a specified height.

[0061] When the motor 11 in the electric drive unit rotates in the opposite direction according to the instruction, the inner mast 3 and the fork head 4 descend under the action of their own weight.

[0062] The fork head 4 can be a three-way fork head 4, which can change the direction of the fork head 4 as needed, and is suitable for the material handling work at narrow roads in factories and warehouses.

[0063] like Figure 4 As shown, the upper sprocket assembly 22 includes a sprocket body 221, an intermediate shaft 223 is inserted into the sprocket body 221, the intermediate shaft 223 is connected to the sprocket body 221 through a bearing 222, and both ends of the intermediate shaft 223 are respectively inserted into two brackets 224, and each of the brackets 224 is inserted with a bolt 225.

[0064] Working principle:

[0065] The motor 11 is connected to the reducer 12 and fixed on the body 1 of the forklift. The output shafts on both sides of the reducer 12 are connected to the drive sprocket 13. The upper sprocket assembly 22 and the lower sprocket assembly 24 are arranged at the upper and lower cross beams of the outer mast 2. The roller chain 23 passes through three sets of sprockets (drive sprocket 13, upper sprocket assembly 22, and lower sprocket assembly 24), and its head and end are fixed on the inner mast 3. The lifting plate chain 33 crosses the inner mast sprocket 32 ​​on the inner mast 3, and its two ends are connected to the outer mast 2 and the fork 4 respectively.

[0066] After the motor 11 is powered on and started, the speed is reduced and the torque is amplified through the speed reducer 12, which drives the drive sprocket 13 to rotate. The drive sprocket 13 drives the roller chain 23 to move. When the roller chain 23 moves, it can pull the inner door frame 3 connected to it to lift. During the lifting process of the inner door frame 3, the inner door frame sprocket 32 ​​inside it acts as a movable pulley. Under the pulling of the lifting plate chain 33, the fork head 4 is lifted at twice the speed of the inner door frame 3. When it is lowered, it is achieved by reversing the motor 11. The lifting and lowering are all controlled by the motor 11, and the speed is stable and reliable and easy to adjust. At the same time, a brake 14 is arranged at the end of the motor 11, which can stop reliably at any lifting and lowering position. An encoder 15 is connected to the output shaft above the motor 11. The encoder 15 reads the speed of the motor 11 and the number of revolutions of the output shaft of the motor 11, and judges the height of the lifting and falling of the fork head 4 through the above values.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pure electric stacking forklift, comprising a body (1) and a fork head (4), characterized in that: The vehicle body (1) is equipped with an electric drive unit, the electric drive unit comprising a motor (11) and a reducer (12), the reducer (12) being installed on the vehicle body (1), and the motor (11) being connected to the reducer (12); The output shaft of the motor (11) is connected to the brake (14), and when the brake (14) is turned on, the output shaft of the motor (11) can be locked; An encoder (15) for measuring the number of rotations of the motor (11) is arranged on the output shaft of the motor (11); An outer door frame (2) is fixedly mounted on the vehicle body (1); an inner door frame (3) can roll up and down via rollers and a first roller track in the outer door frame (2); and a fork head (4) is connected to the inner door frame (3); The electric drive unit is connected to the lifting unit, and the electric drive unit drives the inner door frame (3) and the fork head (4) to rise and fall through the lifting unit.

2. A pure electric stacking forklift according to claim 1, characterized in that: One end of the output shaft of the motor (11) is spline-connected to the reducer (12), and the other end is spline-connected to the brake (14).

3. A pure electric stacking forklift according to claim 1, characterized in that: The lifting unit comprises a driving sprocket (13), two output shafts in the reducer (12) are connected to the driving sprocket (13) via a flat key, and the fork head (4) can roll up and down via a roller and a second raceway in the inner door frame (3).

4. A pure electric stacking forklift according to claim 3, characterized in that: An upper sprocket assembly (22) is fixed above the outer door frame (2), and a lower sprocket assembly (24) is fixed below the outer door frame (2); a roller chain (23) passes around the driving sprocket (13), the upper sprocket assembly (22), and the lower sprocket assembly (24); and the beginning and end ends of the roller chain (23) are fixed to the upper and lower sides of the inner chain plate (31) of the inner door frame (3).

5. A pure electric stacking forklift according to claim 4, characterized in that: The chain hanging plate (31) is fixed to the inner door frame (3) by welding, two roller chains (23) are provided, and the two roller chains (23) are respectively connected to two driving sprocket wheels (13).

6. A pure electric stacking forklift according to claim 5, characterized in that: The fork head (4) is provided with a fork head lifting chain hole (41), and the outer door frame (2) is provided with an outer door frame lifting chain hole (21).

7. A pure electric stacking forklift according to claim 6, characterized in that: An inner mast sprocket (32) is installed on the inner mast (3), and a lifting plate chain (33) is connected to the inner mast sprocket (32), one end of which is fixed at the outer mast lifting chain hole (21), and the other end is fixed at the fork lifting chain hole (41).

8. The pure electric stacking forklift according to claim 7, characterized in that: The upper sprocket assembly (22) comprises a sprocket body (221), an intermediate shaft (223) is inserted into the sprocket body (221), and the intermediate shaft (223) is connected to the sprocket body (221) via a bearing (222).

9. A pure electric stacking forklift according to claim 8, characterized in that: The two ends of the intermediate shaft (223) are respectively inserted into two brackets (224), and a bolt (225) is inserted into each bracket (224).

10. The pure electric stacking forklift according to claim 1, characterized in that: The lifting unit comprises a drum (16) on which a steel wire rope (25) is wound; the two drums (16) are respectively connected to the two output shafts of the reducer (12) via a flat key; and the other end of the steel wire rope is connected to the inner door frame (3).

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