A dual-wheel differential drive device and a leg-insertion type unmanned forklift

Abstract

The present invention relates to a dual-wheel differential drive device, comprising a mounting plate (31) and a differential drive unit in the mounting plate (31), wherein the mounting plate (31) is cylindrical and has a fixed plate (38) at the top, and the differential drive unit is provided with an angle sensor (5), an electromagnetic push rod (9), a side roller (34), and a top roller (35), wherein the side roller (34) and the top roller (35) are in rolling contact with the mounting plate (31) and the fixed plate (38) respectively, and the electromagnetic push rod (9) is arranged along the diameter direction of the mounting plate (31), and the inner side wall of the mounting plate (31) is provided with a plurality of locking jacks (311) matching the electromagnetic push rod (9) at intervals in the circumferential direction. Compared with the prior art, the present invention has the advantages of high control accuracy, strong flexibility, high reliability, etc.

Description

Technical Field

[0001] The present invention relates to the field of forklifts, and in particular to a dual-wheel differential drive device and a leg-insertion type unmanned forklift. Background Art

[0002] AGV (Automated Guided Vehicle, referred to as AGV), also commonly known as unmanned transport vehicle, is a transport vehicle equipped with electromagnetic or optical automatic guidance devices, which can travel along a specified guide path and has safety protection and various transfer functions. Due to its high degree of automation, safety, and flexibility, it is currently one of the best solutions for realizing automatic material handling in China.

[0003] At present, many production workshops or warehouses use AGVs to transport items to improve production or storage efficiency. The existing AGVs have two driving modes: steering wheel drive and differential drive. The steering wheel can achieve omnidirectional movement. The differential drive uses two motors to drive the two wheels separately, and the steering of the wheel system is achieved through the different speeds of the two wheels.

[0004] The steering wheel can achieve omnidirectional movement, but it is expensive and has low load-bearing capacity. Differential drive uses two motors to drive two wheels respectively, and realizes the steering of the wheel system through the different speeds of the two wheels. However, the existing differential drive device has the following two problems:

[0005] First, it is impossible to achieve on-site turning. The AGV equipment using this drive device cannot complete small angle adjustments in a limited space, resulting in poor lateral movement ability and low posture adjustment accuracy.

[0006] Second, each driving wheel of the AGV is driven individually, which requires relatively high control accuracy. Otherwise, there will be inconsistent steering angles, which will reduce the control accuracy and stability of the AGV's movement process. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a two-wheel differential drive device and a leg-type unmanned forklift with high control accuracy, strong flexibility and high reliability.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A dual-wheel differential drive device, comprising a mounting plate and a differential drive unit in the mounting plate, wherein the mounting plate is cylindrical and has a fixed plate at the top, and the differential drive unit is provided with an angle sensor, an electromagnetic push rod, a side roller and a top roller, wherein the side roller is in rolling contact with the mounting plate, and the top roller is in rolling contact with the fixed plate, the electromagnetic push rod is arranged along the diameter direction of the mounting plate, and a plurality of locking sockets matching the electromagnetic push rod are arranged at intervals in the circumferential direction on the inner side wall of the mounting plate;

[0010] The steering angle of the differential drive unit is detected by an angle sensor. When the differential drive unit rotates to a certain steering angle, the electromagnetic push rod extends the push rod and inserts into the locking socket, so that the two-wheel differential drive device is fixed at the current steering angle. The steering angle of the two-wheel differential drive device remains fixed and can accurately perform linear motion or stand still.

[0011] Furthermore, the device further comprises a proximity switch, a first mounting plate is provided on the outer side wall of the mounting plate, the proximity switch is fixed on the first mounting plate and passes through the side wall of the mounting plate along the diameter direction of the mounting plate, and an initial sensing block matching the proximity switch is provided on the differential drive unit;

[0012] The proximity switch can sense the initial sensing block, and the initial calibration of the steering angle of the dual-wheel differential drive device can be achieved by sensing the initial sensing block through the proximity switch.

[0013] Furthermore, a stopper is provided on the differential drive unit, a limit block is provided on the fixed plate, the height of the stopper matches the height of the limit block, and the distance between the stopper and the axis of the mounting plate matches the distance between the limit block and the axis of the mounting plate.

[0014] Furthermore, the number of the limit blocks is two, and the two limit blocks are arranged at intervals along the circumferential direction of the mounting plate;

[0015] When the stopper is blocked by the limiting block, the differential drive unit cannot continue to rotate, thereby limiting the maximum steering angle of the differential drive unit and preventing the wires connected to the differential drive unit from being entangled.

[0016] Further, the differential drive unit comprises a motor compartment, two stepper motors and two driving wheels, the two stepper motors are located in the motor compartment, the two driving wheels are symmetrically arranged on both sides of the motor compartment and are respectively connected to the two stepper motors in a transmission manner, and the side rollers and the top rollers are respectively arranged on the motor compartment;

[0017] The side rollers enable the differential drive unit to be coaxially steered in the mounting plate, and the top rollers play a supporting role.

[0018] Furthermore, a second mounting plate is horizontally provided on the motor compartment, and the angle sensor is provided on the second mounting plate.

[0019] Furthermore, the number of the electromagnetic push rods is two, and the two electromagnetic push rods are symmetrically arranged;

[0020] Two electromagnetic push rods work together to lock the steering angle of the dual-wheel differential drive device, which is highly reliable.

[0021] Furthermore, the device also includes a stop ring, and the stop ring is coaxially fixed to the bottom end of the mounting plate.

[0022] Furthermore, the inner diameter of the stop ring is smaller than the inner diameter of the mounting plate;

[0023] Because the side rollers are in contact with the inner wall of the mounting plate, the stop ring will limit the side rollers to prevent the differential drive unit from detaching from the mounting plate.

[0024] A leg-type unmanned forklift, comprising a forklift body, a fork shovel, a front leg and a two-wheel differential drive device, wherein the number of the two-wheel differential drive devices is four, two of which are symmetrically arranged on the front leg, and the other two are symmetrically arranged on the forklift body;

[0025] The steering and forward movement of each dual-wheel differential drive device are controlled separately. The unmanned forklift can adjust the forward direction of each dual-wheel differential drive device separately without moving, so as to achieve on-site steering, greatly improve the lateral movement and steering capabilities, and have strong flexibility. The forward direction and posture of the mobile equipment can be adjusted quickly and in a small range within a limited space.

[0026] At the same time, the dual-wheel differential drive device has the function of steering lock, which can not only improve the control accuracy of the unmanned forklift during driving, but also achieve on-the-spot parking.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The dual-wheel differential drive device of the present invention comprises a mounting plate and a differential drive unit in the mounting plate. The mounting plate is cylindrical and has a fixed plate at the top. The differential drive unit is provided with an angle sensor, an electromagnetic push rod, a side roller and a top roller. The side roller is in rolling contact with the mounting plate, the top roller is in rolling contact with the fixed plate, the side roller and the top roller are in rolling contact with the mounting plate and the fixed plate respectively. The electromagnetic push rod is arranged along the diameter direction of the mounting plate. A plurality of locking sockets matching the electromagnetic push rod are arranged at intervals in the circumferential direction on the inner side wall of the mounting plate. The steering angle of the differential drive unit is detected by the angle sensor. When the differential drive unit rotates to a certain steering angle, the electromagnetic push rod extends and is inserted into the locking socket, so that the dual-wheel differential drive device is fixed at the current steering angle. The steering angle of the dual-wheel differential drive device remains fixed, and the device can accurately perform linear motion or standstill, and has high reliability.

[0029] (2) The unmanned forklift of the present invention is provided with a two-wheel differential drive device, and the steering and forward processes of each two-wheel differential drive device are independently controlled. The unmanned forklift can independently adjust the forward direction of each two-wheel differential drive device without moving, thereby realizing on-site steering, greatly improving the lateral shift and steering capabilities, and having strong flexibility. The forward direction and posture of the mobile equipment can be adjusted quickly and in a small range within a limited space. At the same time, the two-wheel differential drive device has a steering lock function, thereby improving the control accuracy and stability of the unmanned forklift during driving. When the steering of at least two two-wheel differential drive devices is locked and the steering angles are inconsistent, the unmanned forklift cannot move, thereby realizing on-site parking, preventing the unmanned forklift from moving during loading and unloading, and having good safety.

[0030] (3) A first mounting plate is provided on the outer side wall of the mounting plate of the present invention, a proximity switch passes through the side wall of the mounting plate along the diameter direction of the mounting plate, an initial sensing block matching the proximity switch is provided on the differential drive unit, and the proximity switch can sense the initial sensing block to achieve initial calibration of the steering angle of the dual-wheel differential drive device;

[0031] (4) A stopper is provided on the differential drive unit of the present invention, and a limit block is provided on the fixed disk. The height of the stopper matches the height of the limit block. The distance between the stopper and the axis of the mounting disk matches the distance between the limit block and the axis of the mounting disk. There are two limit blocks, which are arranged at intervals along the circumferential direction of the mounting disk. When the stopper is blocked by the limit block, the differential drive unit cannot continue to rotate, thereby limiting the maximum steering angle of the differential drive unit and preventing the wires connected to the differential drive unit from being entangled.

[0032] (5) The number of electromagnetic push rods of the present invention is two, and the two electromagnetic push rods are symmetrically arranged. The two electromagnetic push rods jointly realize the locking of the steering angle of the dual-wheel differential drive device, and the reliability is strong;

[0033] (6) The stop ring of the present invention is coaxially fixed to the bottom end of the mounting plate, and the inner diameter of the stop ring is smaller than the inner diameter of the mounting plate. Because the side roller contacts the inner wall of the mounting plate, the stop ring will limit the side roller and prevent the differential drive unit from detaching from the mounting plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a side view of the unmanned forklift;

[0035] Figure 2 This is a bottom view of the unmanned forklift;

[0036] Figure 3 It is a schematic diagram of the assembly of the front legs and the differential drive wheels;

[0037] Figure 4 is a schematic diagram of the three-dimensional structure of the differential drive wheel;

[0038] Figure 5 It is a schematic diagram of the three-dimensional structure of a differential drive unit having one side of an initial induction block;

[0039] Figure 6 It is a schematic diagram of the three-dimensional structure of the differential drive unit on the side opposite to the initial sensing block;

[0040] Figure 7 is a side view of a differential drive unit;

[0041] Figure 8 is a bottom view of the differential drive unit;

[0042] Fig. 9 is a cross-sectional view of a differential drive unit;

[0043] Fig.10 It is a schematic diagram of the assembly of the mounting plate and the fixing plate;

[0044] Description of the numbers in the figure:

[0045] 1. Forklift body, 2. Fork shovel, 3. Two-wheel differential drive device, 4. Front leg, 5. Angle sensor, 6. Limit block, 7. Proximity switch, 8. Initial sensing block, 9. Electromagnetic push rod, 10. Stop ring, 31. Mounting plate, 32. Motor compartment, 33. Driving wheel, 34. Side roller, 35. Top roller, 36. Block, 37. Stepper motor, 38. Fixed plate, 39. First mounting plate, 40. Cover plate, 41. Wire trough shield, 311. Locking jack, 321. Second mounting plate. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0047] Example 1

[0048] A two-wheel differential drive device, such as Figure 4 and Fig. 9 , including a mounting plate 31 and a differential drive unit in the mounting plate 31, the mounting plate 31 is cylindrical, and a fixed plate 38 is provided at the top, the differential drive unit is provided with an angle sensor 5, an electromagnetic push rod 9, a side roller 34 and a top roller 35, the side roller 34 is in rolling contact with the mounting plate 31, the top roller 35 is in rolling contact with the fixed plate 38, and the electromagnetic push rod 9 is arranged along the diameter direction of the mounting plate 31, as shown in FIG. Fig.10 The inner side wall of the mounting plate 31 is provided with a plurality of locking holes 311 which match the electromagnetic push rod 9 at intervals in an annular direction;

[0049] The steering angle of the differential drive unit is detected by the angle sensor 5. When the differential drive unit rotates to a certain steering angle, the electromagnetic push rod 9 extends the push rod and inserts into the locking socket 311, so that the two-wheel differential drive device is fixed at the current steering angle. The steering angle of the two-wheel differential drive device remains fixed and can accurately perform linear motion or stand still.

[0050] A cover plate 40 having a protective function is provided on the fixing plate 38 .

[0051] like Figure 5 , Figure 6 , Figure 7 and Figure 8 The differential drive unit includes a motor compartment 32, two stepper motors 37 and two driving wheels 33. The two stepper motors 37 are located in the motor compartment 32. The two driving wheels 33 are symmetrically arranged on both sides of the motor compartment 32 and are respectively connected to the two stepper motors 37. The side rollers 34 and the top rollers 35 are respectively arranged on the motor compartment 32.

[0052] The side rollers 34 enable the differential drive unit to be coaxially steered within the mounting plate 31 , and the top rollers 35 play a supporting role.

[0053] A second mounting plate 321 is horizontally disposed on the motor compartment 32 , and the angle sensor 5 is disposed on the second mounting plate 321 .

[0054] There are two electromagnetic push rods 9, which are symmetrically arranged. The two electromagnetic push rods 9 jointly realize the locking of the steering angle of the dual-wheel differential drive device, and have high reliability.

[0055] like Fig. 9 The device also includes a stop ring 10, which is coaxially fixed at the bottom end of the mounting plate 31. The inner diameter of the stop ring 10 is smaller than the inner diameter of the mounting plate 31. Because the side roller 34 contacts the inner wall of the mounting plate 31, the stop ring 10 will limit the side roller 34 and prevent the differential drive unit from detaching from the mounting plate 31.

[0056] Example 2

[0057] In this embodiment, a two-wheel differential drive device further includes a proximity switch 7, a first mounting plate 39 is provided on the outer side wall of the mounting plate 31, the proximity switch 7 is fixed on the first mounting plate 39, and passes through the side wall of the mounting plate 31 along the diameter direction of the mounting plate 31, and an initial sensing block 8 matching the proximity switch 7 is provided on the differential drive unit;

[0058] The proximity switch 7 can sense the initial sensing block 8 to achieve the initial calibration of the steering angle of the dual-wheel differential drive device.

[0059] Example 3

[0060] In this embodiment, a stopper 36 is provided on the differential drive unit, and a limit block 6 is provided on the fixed disk 38. The height of the stopper 36 matches the height of the limit block 6, and the distance between the stopper 36 and the axis of the mounting disk 31 matches the distance between the limit block 6 and the axis of the mounting disk 31. There are two limit blocks 6, and the two limit blocks 6 are arranged at an annular interval along the mounting disk 31. The angle between the two limit blocks 6 is 90°. When the stopper 36 is blocked by the limit block 6, the differential drive unit cannot continue to rotate, thereby limiting the maximum steering angle of the differential drive unit. The maximum steering angle is 270°, which avoids entanglement of the wires connected to the differential drive unit.

[0061] The rest is the same as Example 1.

[0062] Example 4

[0063] In this embodiment, a leg-type unmanned forklift, such as Figure 1 , Figure 2 and Figure 3 , comprising a forklift body 1, a fork shovel 2, a front leg 4 and the two-wheel differential drive devices 3 described in embodiments 1 to 3, the number of the two-wheel differential drive devices 3 is 4, two of which are symmetrically arranged on the front leg 4, and the other two are symmetrically arranged on the forklift body 1;

[0064] A wire slot shield 41 for wiring is provided on the front leg 4 .

[0065] The steering and forward movement of each dual-wheel differential drive device 3 are controlled separately. The unmanned forklift can adjust the forward direction of each dual-wheel differential drive device 3 separately without moving, so as to achieve on-site steering. The lateral movement and steering capabilities are greatly improved, and the flexibility is strong. The forward direction and posture of the mobile equipment can be adjusted quickly and in a small range in a limited space.

[0066] At the same time, the two-wheel differential drive device 3 has a steering lock function, which can improve the control accuracy of the unmanned forklift during driving. When at least two two-wheel differential drive devices 3 are locked and the steering angles are inconsistent, the unmanned forklift cannot move, thereby achieving on-site parking and preventing the unmanned forklift from moving during loading and unloading, which has good safety.

[0067] Embodiment 1, embodiment 2, embodiment 3 and embodiment 4 propose a two-wheel differential drive device and a leg-type unmanned forklift. The two-wheel differential drive device 3 can achieve steering lock and can accurately perform linear motion or standstill. The leg-type unmanned forklift equipped with a plurality of two-wheel differential drive devices 3 can not only adjust the forward direction and position of the mobile equipment in a small and fast manner within a limited space, but also can achieve on-the-spot parking and has high reliability.

[0068] The steering angle of the differential drive unit is detected by the angle sensor 5. When the differential drive unit rotates to a certain steering angle, the electromagnetic push rod 9 extends the push rod and inserts into the locking socket 311, so that the two-wheel differential drive device is fixed at the current steering angle. The steering angle of the two-wheel differential drive device remains fixed and can accurately perform linear motion or stand still.

[0069] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A two-wheel differential drive device, characterized in that: The invention comprises a mounting plate (31) and a differential drive unit in the mounting plate (31), wherein the mounting plate (31) is cylindrical and has a fixed plate (38) at the top, and the differential drive unit is provided with an angle sensor (5), an electromagnetic push rod (9), a side roller (34) and a top roller (35), wherein the side roller (34) is in rolling contact with the mounting plate (31), and the top roller (35) is in rolling contact with the fixed plate (38), the electromagnetic push rod (9) is arranged along the diameter direction of the mounting plate (31), and a plurality of locking sockets (311) matching the electromagnetic push rod (9) are arranged at intervals in the circumferential direction on the inner side wall of the mounting plate (31); The device further comprises a proximity switch (7), a first mounting plate (39) is provided on the outer side wall of the mounting plate (31), the proximity switch (7) is fixed on the first mounting plate (39) and passes through the side wall of the mounting plate (31) along the diameter direction of the mounting plate (31), and an initial sensing block (8) matching the proximity switch (7) is provided on the differential drive unit; The differential drive unit comprises a motor compartment (32), two stepper motors (37) and two driving wheels (33); the two stepper motors (37) are located in the motor compartment (32); the two driving wheels (33) are symmetrically arranged on both sides of the motor compartment (32) and are respectively connected to the two stepper motors (37); and the side rollers (34) and the top roller (35) are respectively arranged on the motor compartment (32).

2. A two-wheel differential drive device according to claim 1, characterized in that: The differential drive unit is provided with a stopper (36), the fixed plate (38) is provided with a limit block (6), the height of the stopper (36) matches the height of the limit block (6), and the distance between the stopper (36) and the axis of the mounting plate (31) matches the distance between the limit block (6) and the axis of the mounting plate (31).

3. A two-wheel differential drive device according to claim 2, characterized in that: The number of the limit blocks (6) is two, and the two limit blocks (6) are arranged at intervals along the circumferential direction of the mounting plate (31).

4. A two-wheel differential drive device according to claim 1, characterized in that: A second mounting plate (321) is horizontally disposed on the motor compartment (32), and the angle sensor (5) is disposed on the second mounting plate (321).

5. A two-wheel differential drive device according to claim 1, characterized in that: The number of the electromagnetic push rods (9) is two, and the two electromagnetic push rods (9) are symmetrically arranged.

6. A two-wheel differential drive device according to claim 1, characterized in that: The device further comprises a stop ring (10), wherein the stop ring (10) is coaxially fixed to the bottom end of the mounting plate (31).

7. A two-wheel differential drive device according to claim 6, characterized in that: The inner diameter of the stop ring (10) is smaller than the inner diameter of the mounting plate (31).

8. A leg-type unmanned forklift, characterized in that: The forklift comprises a forklift body (1), a fork shovel (2), a front leg (4), and a two-wheel differential drive device (3) as claimed in any one of claims 1 to 7, wherein the number of the two-wheel differential drive devices (3) is four, two of which are symmetrically arranged on the front leg (4), and the other two are symmetrically arranged on the forklift body (1).

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