Carrying vehicle

Abstract

The embodiment of the invention provides a carrier. The carrier comprises a front frame, a rear frame, a first frame connecting rod, a second frame connecting rod and a lifting power device. The front frame serves as a first rack and is hinged to the first frame connecting rod and the second frame connecting rod, and the rear frame serves as a first connecting rod and is hinged to the first frame connecting rod and the second frame connecting rod, so that the first rack, the first frame connecting rod, the second frame connecting rod and the first connecting rod form a first parallelogram mechanism; the lifting power device is arranged on the front frame, and in the process of providing lifting power for the rear frame and lifting the rear frame from the low-position state to the high-position state, the first frame connecting rod and the second frame connecting rod rotate synchronously. Relative deflection of the front frame and the rear frame can be avoided, the synchronism of horizontal movement of the front frame and the rear frame in the lifting process of the rear frame is improved, and then the stability of goods carrying of the carrier is improved.

Description

Technical Field

[0001] The present application relates to the technical field of warehousing and logistics equipment, and in particular to a transport vehicle. Background Art

[0002] AGV (Automated Guided Vehicle) trucks are widely used in logistics and warehousing. They can fork and lift goods and transport them along preset routes.

[0003] like Figure 1 As shown, an existing AGV transporter mainly consists of a front frame 1, a rear frame 2, a rocker arm 3, and a hydraulic drive mechanism 4. A guide wheel 5 is mounted on the back of the rear frame 2. The guide wheel 5 forms a sliding connection with the front frame 1 that allows for a slight tilting motion, allowing the rear frame 2 and the front frame 1 to tilt forward and backward with the center N of the guide wheel 5 as the axis. The first hinge point O of the rocker arm 3 is connected to the front frame 1, while the second hinge point M is connected to the rear frame 2. The top of the push rod of the hydraulic drive mechanism 4 extends into the first groove on the back of the rear frame 2, while the bottom of its cylinder extends into the second groove of the front frame 1. Through the action of the hydraulic drive mechanism 4, the rear frame 2 can be driven to move upward.

[0004] However, combined Figure 1 and Figure 2 It can be observed that when the rear frame 2 is ascending, the bottom of the rear frame 2 drives the rocker arm 3 to rotate around the first hinge point O, thereby generating a vertical displacement component Y1 and a horizontal displacement component X1. This will cause a certain amount of relative deflection (forward and backward tilt) between the front frame 1 and the rear frame 2, thereby affecting the synchronization of the horizontal movement of the front frame 1 and the rear frame 2 during the process of the AGV transporter lifting the rear frame 2. For example, Figure 1 and Figure 2 As shown in FIG. 1 , when the front frame 1 remains in the same position, the center N of the top of the rear frame 2 only generates a vertical displacement component Y0, but no horizontal displacement component. However, the bottom of the rear frame 2 generates a horizontal displacement component X1, which means that a certain angle of deflection will occur between the rear frame 2 and the front frame 1. For example, the loading surface of the rear frame 2 is deflected from Figure 1 The P surface deflects to Figure 2 This deflection can easily cause the cargo on the loading surface of the rear frame 2 to become unstable during the lifting process. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a transport vehicle to solve the problem of poor synchronization of horizontal movement between the front and rear frames during the lifting and lowering of the rear frame. The specific technical solution is as follows:

[0006] A transport vehicle comprising:

[0007] front frame;

[0008] rear frame;

[0009] First connecting rod;

[0010] The second connecting rod; wherein the front frame serves as the first frame and is hinged to the first connecting rod and the second connecting rod respectively; the rear frame serves as the first connecting rod and is hinged to the first connecting rod and the second connecting rod respectively, and the first frame, the first connecting rod, the second connecting rod and the first connecting rod form a first parallelogram mechanism;

[0011] The lifting power device is arranged on the front frame and is used to provide lifting power for the rear frame, so that the first connecting rod and the second connecting rod rotate synchronously to lift the rear frame from a low position to a high position.

[0012] In some embodiments, it further includes:

[0013] The first load-bearing wheel assembly includes: a first wheel frame, a first wheel set and a first transmission connecting rod; wherein,

[0014] The first wheel frame is sequentially provided with a first connecting end, a second connecting end and a third connecting end;

[0015] The first wheel assembly is arranged at the first connecting end of the first wheel frame;

[0016] The rear frame serves as the second frame and is further hinged to the second connecting end of the first wheel frame, so that the first wheel frame and the first connecting rod both serve as connecting rods connecting the second frame, and the first transmission link is hinged to the third connecting end of the first wheel frame and the first connecting rod respectively, so that the second frame, the first wheel frame, the first connecting rod and the first transmission link form a hinged four-bar mechanism;

[0017] Among them, the positions where the first connecting rod is hinged to the rear frame and the first transmission link are different. Under the swing of the first connecting rod, the first connecting rod can push the first wheel frame to rotate through the first transmission link. When the rear frame is in a high position, the first wheel group is lowered relative to the rear frame to support the rear frame.

[0018] In some embodiments, the lifting power unit includes: a motor drive assembly, a swing arm, and a fork synchronization link;

[0019] The motor drive assembly is arranged on the front frame, the first end of the swing arm is connected to the drive shaft of the motor drive assembly, so that the drive shaft of the motor drive assembly can drive the swing arm to swing along the axis of the drive shaft, and the two ends of the fork synchronization link are respectively hinged to the second end of the swing arm and the rear frame, wherein the front frame serves as the first frame, the rear frame serves as the slider, and the first frame, the swing arm, the fork synchronization link and the slider form a crank slider mechanism;

[0020] When the swing arm rotates to a first angle, the rear frame is in a low position; when the swing arm rotates to a second angle, the swing arm drives the rear frame to a high position through the fork synchronous connecting rod.

[0021] In some embodiments, the lifting power device further comprises: a spherical bearing and a limiter;

[0022] The spherical plain bearing comprises an inner ring and an outer ring, wherein the outer surface of the inner ring is rotatably connected to the inner surface of the outer ring;

[0023] A bearing chamber is provided at one end of the fork synchronization link, the outer ring is provided in the bearing chamber, and the inner ring is provided at the second end of the swing arm, so that the one end of the fork synchronization link and the second end of the swing arm are hinged;

[0024] The limiting piece is used to limit the outer ring so that it remains in the bearing chamber.

[0025] In some embodiments, the motor drive assembly includes: a motor, a speed reducer, and a proximity sensor;

[0026] The first side of the reducer is in transmission connection with the motor, and the second side of the reducer is provided with an output shaft, which serves as the driving shaft of the motor drive assembly and is connected to the first end of the swing arm;

[0027] The proximity sensor is arranged at a position corresponding to the first angle on the second side of the reducer, so that when the swing arm rotates to the first angle, the proximity sensor senses the swing arm triggering a position sensing signal, and the motor stops rotating according to the position sensing signal.

[0028] In some embodiments, the motor includes: a motor body and an encoder;

[0029] The encoder is used to record the number of rotations of the motor body. The motor body stops rotating after the number of rotations reaches the command number of rotations. The command number of rotations is calculated based on the rear frame lifting height input by the user.

[0030] In some embodiments, the first position where the fork synchronization link is hinged to the rear frame is lower than the second position where the fork synchronization link is hinged to the second end of the swing arm, so that the fork synchronization link is a pull rod.

[0031] In some embodiments, it further includes:

[0032] A steering wheel, located at the bottom of the front frame;

[0033] The fork synchronization link includes a first rod segment and a second rod segment. The first end of the first rod segment is hinged to the rear frame, the first end of the second rod segment is hinged to the second end of the swing arm, and the second end of the first rod segment and the second end of the second rod segment are bent and connected in a direction away from the steering wheel to form a space to avoid the steering wheel.

[0034] In some embodiments, the third position where the fork synchronization link is hinged to the rear frame is higher than the fourth position where the fork synchronization link is hinged to the second end of the swing arm, so that the fork synchronization link is a push rod.

[0035] In some embodiments, the rear frame includes: a backrest, a first fork and a second fork, wherein the first fork and the second fork are spaced apart and respectively connected to the bottom of the backrest;

[0036] The second connecting end of the first wheel frame is rotatably provided on the first fork, and when the rear frame is in a high position, the first wheel assembly is lowered relative to the first fork to support the first fork;

[0037] a third connecting rod and a fourth connecting rod; wherein the front frame serves as the first frame and is hinged to the third connecting rod and the fourth connecting rod respectively; and the rear frame serves as the second connecting rod and is hinged to the third connecting rod and the fourth connecting rod respectively, so that the first frame, the third connecting rod, the fourth connecting rod and the second connecting rod form a second parallelogram mechanism; the lifting power device is also used to provide lifting power for the rear frame, so that the third connecting rod and the fourth connecting rod rotate synchronously, thereby lifting the rear frame from a low position to a high position;

[0038] The second load-bearing wheel assembly includes: a second wheel frame, a second wheel set and a second transmission connecting rod; wherein,

[0039] The second wheel frame is sequentially provided with a fourth connecting end, a fifth connecting end, and a sixth connecting end. The second wheel set is provided at the fourth connecting end of the second wheel frame. The fifth connecting end of the second wheel frame is rotatably provided on the second fork. The second transmission connecting rod is rotatably connected to the sixth connecting end of the second wheel frame and the third connecting rod respectively.

[0040] Among them, under the swing of the third connecting rod, the third connecting rod can push the second wheel frame to rotate through the second transmission connecting rod. When the rear frame is in a high position, the second wheel group is lowered relative to the second fork to support the second fork.

[0041] In some embodiments, at least one of the first transmission link and the second transmission link is adjustable in length.

[0042] In some embodiments, the front frame includes: a supporting cross plate, a first connecting portion, a second connecting portion, a third connecting portion, and a fourth connecting portion, the lifting power device is disposed on the supporting cross plate, the first connecting portion and the second connecting portion are sequentially disposed on the supporting cross plate along the height direction of the transport vehicle and are located on one side of the lifting power device, and the third connecting portion and the fourth connecting portion are sequentially disposed on the supporting cross plate along the height direction of the transport vehicle and are located on the other side of the lifting power device;

[0043] The rear frame includes: a fifth connecting portion, a sixth connecting portion, a seventh connecting portion and an eighth connecting portion, the fifth connecting portion and the sixth connecting portion are sequentially arranged on the backrest shelf along the height direction of the transport vehicle, and the seventh connecting portion and the eighth connecting portion are sequentially arranged on the backrest shelf along the height direction of the transport vehicle;

[0044] Two ends of the first connecting rod are hinged to the first connecting portion and the fifth connecting portion respectively, and two ends of the second connecting rod are hinged to the second connecting portion and the sixth connecting portion respectively;

[0045] Two ends of the third connecting rod are hinged to the third connecting portion and the seventh connecting portion respectively, and two ends of the fourth connecting rod are hinged to the fourth connecting portion and the eighth connecting portion respectively.

[0046] In some embodiments, the front frame further comprises: a fence riser;

[0047] The supporting transverse plate has an inner side close to the shelf and an outer side away from the shelf;

[0048] The first connecting portion, the second connecting portion, the third connecting portion and the fourth connecting portion are arranged on the inner side of the supporting transverse plate close to the shelf;

[0049] The vertical plate of the enclosure is wrapped around the outer side of the supporting horizontal plate away from the shelf.

[0050] Beneficial effects of the embodiments of the present application:

[0051] The transport vehicle provided in an embodiment of the present application includes a front frame, a rear frame, a first connecting rod, a second connecting rod, and a lifting power device. The front frame serves as a first frame and is hinged to the first connecting rod and the second connecting rod respectively. The rear frame serves as a first connecting rod and is hinged to the first connecting rod and the second connecting rod respectively, so that the first frame, the first connecting rod, the second connecting rod, and the first connecting rod form a first parallelogram mechanism. The lifting power device is provided on the front frame. When providing lifting power to the rear frame and lifting the rear frame from a low position to a high position, the first connecting rod and the second connecting rod rotate synchronously. Since the first frame, the first connecting rod, the second connecting rod, and the first connecting rod form the first parallelogram mechanism, the front frame and the rear frame can be prevented from relative deflection, thereby improving the synchronization of the horizontal movement of the front frame and the rear frame during the lifting process of the rear frame, thereby improving the stability of the transport vehicle in transporting goods.

[0052] Of course, implementing any product or method of the present application does not necessarily require achieving all of the above advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0054] Figure 1 This is a structural diagram of an AGV transport vehicle before lifting in the related art;

[0055] Figure 2 for Figure 1 The schematic diagram of the structure of the AGV transport vehicle after lifting is shown;

[0056] Figure 3 A schematic structural diagram of a transport vehicle provided in an embodiment of the present application with its rear frame in a low position;

[0057] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure of AA;

[0058] Figure 5 for Figure 4 Enlarged view of the middle M;

[0059] Figure 6 for Figure 3 The cross-sectional structural diagram of the transporter rear frame shown is in the high position AA;

[0060] Figure 7 for Figure 3 Schematic diagram of the cross-sectional structure of the middle BB;

[0061] Figure 8 for Figure 3 The cross-sectional structural diagram of the transporter rear frame shown is in the high position BB position;

[0062] Figure 9 for Figure 3 The diagram shows a partial structure of the power unit for lifting the front frame of the transporter;

[0063] Figure 10 for Figure 9 The exploded view of the lifting power unit shown;

[0064] Figure 11 for Figure 4 Enlarged view of N in the middle;

[0065] Figure 12 for Figure 3 The schematic diagram of the structure of the transporter showing a hidden portion of the rear frame;

[0066] Figure 13 for Figure 3The structure diagram of the rear frame of the transporter shown Figure 1 ;

[0067] Figure 14 for Figure 3 The structure diagram of the rear frame of the transporter shown Figure 2 ;

[0068] Figure 15 for Figure 3 The schematic structural diagram of the front frame of the transporter shown;

[0069] Figure 16 A schematic structural diagram of a transport vehicle provided in an embodiment of the present application using another type of fork synchronization connecting rod;

[0070] Figure 17 for Figure 16 A schematic cross-sectional view of the transport vehicle shown;

[0071] Figure 18 for Figure 16 The schematic diagram of the structure of the transporter with the rear frame partially hidden is shown.

[0072] Figure 1 and Figure 2 The reference numerals are as follows:

[0073] Front frame 1, rear frame 2, swing arm 3, hydraulic drive mechanism 4, guide wheel 5;

[0074] Figures 3 to 18 The reference numerals are as follows:

[0075] Front frame 10, supporting cross plate 11, first connecting portion 12A, second connecting portion 13A, third connecting portion 12B, fourth connecting portion 13B, enclosure vertical plate 14;

[0076] Rear frame 20, cargo backrest 21, first cargo fork 22A, second cargo fork 22B, fifth connecting portion 23A, sixth connecting portion 24A, seventh connecting portion 23B, eighth connecting portion 24B;

[0077] First connecting rod 30A, second connecting rod 40A, third connecting rod 30B, fourth connecting rod 40B;

[0078] Lifting power device 50, motor drive assembly 51, motor 511, reducer 512, output shaft 5121, proximity sensor 513, swing arm 52, fork synchronization link 53, first rod segment 531, second rod segment 532, joint bearing 54, limiter 55;

[0079] First load-bearing wheel assembly 60A, first wheel frame 61A, first connecting end 611A, second connecting end 612A, third connecting end 613A, first wheel set 62A, first transmission link 63A, rod body 631A, stud 632A, self-locking nut 633A, rod mounting seat 634A, butterfly spring 635A, second load-bearing wheel assembly 60B, second wheel frame 61B, fourth connecting end 611B, fifth connecting end 612B, sixth connecting end 613B, second wheel set 62B, second transmission link 63B;

[0080] steering wheel 70;

[0081] Universal wheel 80;

[0082] The first position w1, the second position w2, the third position w3, and the fourth position w4. DETAILED DESCRIPTION

[0083] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field based on this application are within the scope of protection of this application.

[0084] like Figure 1 and Figure 2 The AGV shown uses a single rocker arm 3 to connect the front and rear frames 1 and 2. A guide wheel 5 on the rear of the rear frame 2 forms a sliding connection with the front frame 1, allowing for liftability. During the lifting of the rear frame 2, the swinging motion of the rocker arm 3 generates a horizontal displacement component X1 on the bottom of the rear frame 2. This displacement component X1 causes the rear frame 2 and the front frame 1 to tilt slightly forward and backward. This tilt causes the load surface of the rear frame 2 to change angle, directly affecting the horizontal stability of the cargo during the lifting process.

[0085] To address the above issues, the embodiments of this application explore a multi-link coordinated motion solution. This utilizes the parallelogram mechanism's characteristic of parallel opposite sides of equal length, with the front frame serving as the main frame and the rear frame as the movable links, connected via two connecting rods to form a parallelogram mechanism. This design prevents the rear frame from tilting forward or backward relative to the front frame during the lifting process, thereby resolving the issue of poor synchronization in the horizontal movement of the front and rear frames during the rear frame lifting process. This design avoids a certain amount of relative deflection between the front and rear frames, ensuring horizontal synchronization between the two.

[0086] Figure 3 This is a structural diagram of a transport vehicle rear frame 20 in a low position provided by an embodiment of the present application. Figure 4 for Figure 3Schematic diagram of the cross-sectional structure of AA. Figure 3 and Figure 4 As shown, a transport vehicle includes: a front frame 10 , a rear frame 20 , a first connecting rod 30A, a second connecting rod 40A and a lifting power device 50 .

[0087] Figure 5 for Figure 4 The enlarged view of M in the figure. Figure 5 As shown, the front frame 10 serves as the first frame and is hinged to the first and second connecting rods 30A, 40A, respectively. The rear frame 20 serves as the first connecting rod and is also hinged to the first and second connecting rods 30A, 40A, respectively. The front frame 10 and the first connecting rod 30A are hinged at hinge point 1 P1, the front frame 10 and the second connecting rod 40A are hinged at hinge point 2 P2, the rear frame 20 and the first connecting rod 30A are hinged at hinge point 3 P3, and the rear frame 20 and the second connecting rod 40A are hinged at hinge point 4 P4. In this embodiment, the length of the line connecting P1 and P2 is equal to the length of the line connecting P3 and P4, and the length of the line connecting P2 and P4 is also equal to the length of the line connecting P1 and P3. This allows the first frame, the first connecting rod 30A, the second connecting rod 40A, and the first connecting rod to form a first parallelogram mechanism.

[0088] Figure 6 for Figure 3 The cross-sectional view of the rear frame 20 of the transport vehicle is shown in the high position AA. Figure 5 and Figure 6 As shown, the lifting power device 50 is provided on the front frame 10 for providing lifting power for the rear frame 20 so as to rotate the first connecting rod 30A and the second connecting rod 40A synchronously, thereby lifting the rear frame 20 from a low position to a high position.

[0089] The operating process and principle of the embodiment of the present application are as follows: When the lifting power unit 50 is in operation, it drives the first connecting rod 30A and the second connecting rod 40A to rotate synchronously, lifting the rear frame 20 from a low position to a high position. Because the rear frame 20 is constrained by the first parallelogram mechanism, the lines connecting P1 and P2, and P3 and P4, remain parallel during the lifting process. This geometric constraint ensures that the front frame 10 and rear frame 20 remain parallel, preventing fore-and-aft tilting and relative deflection, and improving the synchronization of the horizontal movement of the front frame 10 and rear frame 20. Therefore, the rear frame 20 can maintain a horizontal position during the lifting process, thereby maintaining the stability of the cargo on the loading surface.

[0090] The front frame 10 and rear frame 20 can be constructed of metal structures to meet the support strength requirements of the transport truck, and are not limited to single-piece or assembled components. A steering wheel 70 and universal wheels 80 can be installed at the bottom of the front frame 10. The steering wheel 70 is used to drive the movement and steering of the transport truck. Two universal wheels 80 can be provided, one on each side of the steering wheel 70, to enhance the stability of the front frame 10. The first connecting rod 30A and the second connecting rod 40A can be hinged to the front frame 10 and the rear frame 20, respectively, via a rotating shaft.

[0091] In conventional technology, the lifting power device 50 uses a hydraulic drive mechanism, but there are problems such as oil leakage risk, high maintenance cost, high energy consumption, and large space occupation. Therefore, in order to improve the above problems, in the following embodiments of the present application, the lifting power device 50 adopts an electric drive method. Figure 7 for Figure 3 Schematic diagram of the cross-sectional structure of BB ( Figure 7 The steering wheel 70 is hidden in the Figure 8 for Figure 3 The cross-sectional structure diagram of the transport vehicle rear frame 20 in the high position BB position ( Figure 8 The steering wheel 70 is hidden in the Figure 9 for Figure 3 The front frame 10 of the transport truck is a partial structural diagram of the lifting power device 50. Figure 7 、 Figure 8 and Figure 9 As shown, the lifting power unit 50 includes a motor drive assembly 51, a swing arm 52, and a fork synchronization link 53. The motor drive assembly 51 is mounted on the front frame 10. The first end of the swing arm 52 is connected to the drive shaft of the motor drive assembly 51, so that the drive shaft of the motor drive assembly 51 can drive the swing arm 52 to swing about the axis of the drive shaft. The two ends of the fork synchronization link 53 are respectively hinged to the second end of the swing arm 52 and the rear frame 20. The front frame 10 serves as the first frame, and the rear frame 20 serves as the slider. The first frame, swing arm 52, fork synchronization link 53, and slider form a slider-crank mechanism. When the swing arm 52 rotates to a first angle, the rear frame 20 is in a low position. When the swing arm 52 rotates to a second angle, the swing arm 52 drives the rear frame 20 to a high position via the fork synchronization link 53.

[0092] The axis of the drive shaft of the motor drive assembly 51 can be parallel to the axis of the rotating shaft connecting the first connecting rod 30A and the second connecting rod 40A. The lifting and lowering motion of the rear frame 20 is restricted by the first parallelogram mechanism, and its motion trajectory is an arc (i.e., the sliding trajectory of the slider). The crank slider mechanism satisfies the sliding of the rear frame 20 along this arc. After the motor drive assembly 51 is activated, the drive shaft outputs rotational motion, driving the swing arm 52 to swing about its axis. When the swing arm 52 rotates from the first angle to the second angle, the motion trajectory of the second end of the swing arm 52 is a circular arc path. This is transmitted through the articulation of the fork synchronization link 53, converted into the sliding of the rear frame 20 along this arc, achieving lifting and lowering motion.

[0093] The above-mentioned electrically driven lifting power device 50 has the following advantages:

[0094] like Figure 1 and Figure 2 To accommodate small forward and backward tilting of the rear frame 20 and front frame 10, the illustrated AGV requires the top of the hydraulic drive mechanism's push rod to extend into a first groove on the back of the rear frame 20, while the bottom of the cylinder extends into a second groove on the front frame 10, resulting in a relatively complex structure. However, in the embodiment of the present application, through the organic combination of a crank slider mechanism and a first parallelogram mechanism, the ends of the fork synchronization link 53 of the lifting power unit 50 are articulated to the second end of the swing arm 52 and the rear frame 20, respectively. This simplifies the overall structure of the transporter and enhances operational stability.

[0095] In addition, the energy efficiency conversion rate of the hydraulic drive mechanism is generally 60% to 70%, while the energy efficiency conversion rate of the motor drive assembly 51 can reach over 85%. Therefore, the transport vehicle of the embodiment of the present application can effectively save energy consumption. The motor drive assembly 51 is maintenance-free and there is no risk of oil leakage, which can effectively reduce maintenance costs and make the transport vehicle suitable for industries with high cleanliness requirements such as food and medicine. In low-temperature environments, the hydraulic drive mechanism may cause sluggish movement due to the high viscosity of low-temperature oil, while the motor drive assembly 51 of the present application has a wide temperature adaptability range and is less affected by low temperatures. The operating noise of the motor drive assembly 51 is lower than that of the hydraulic drive mechanism, making it easy to reduce the operating noise of the transport vehicle. The motor drive assembly 51 has a high degree of integration, eliminating components such as hydraulic pumps, valve blocks, and oil tanks, which can effectively reduce the failure rate of the transport vehicle. At the same time, the motor drive assembly 51 takes up less space, making it easy to reduce the turning radius of the transport vehicle.

[0096] like Figure 7 、 Figure 8 and Figure 9As shown, the first position w1 at which the fork synchronization link 53 is hinged to the rear frame 20 is lower than the second position w2 at which the fork synchronization link 53 is hinged to the second end of the swing arm 52, making the fork synchronization link 53 a pull rod. When the swing arm 52 rotates from the first angle to the second angle, the fork synchronization link 53 pulls the rear frame 20 upward.

[0097] In some cases, the fork synchronization link 53 of the straight structure is easy to mate with the steering wheel 70 ( Figure 7 and Figure 8 Not shown, can be combined Figure 6 (as shown) spatial interference affects the stability of the mechanism. In the embodiment of the present application, the fork synchronization link 53 includes a first segment 531 and a second segment 532. The first end of the first segment 531 is hinged to the rear frame 20, and the first end of the second segment 532 is hinged to the second end of the swing arm 52. The second end of the first segment 531 and the second end of the second segment 532 are bent and connected away from the steering wheel 70, creating a space to avoid the steering wheel 70.

[0098] The first rod segment 531 is connected to the rear frame 20 via a rotating shaft to transmit tension, while the second rod segment 532 is hinged to the swing arm 52 to receive driving force. The first and second rod segments 531, 532 are integrally connected to the rear frame 20 and the swing arm 52 using an L-shaped bend. The bend angle can be set between 60° and 120° (e.g., 60°, 70°, 80°, 90°, 100°, 110°, or 120°), depending on the distance between the steering wheel 70 and the fork synchronization link 53, to ensure that the two maintain a sufficient safety distance.

[0099] This application effectively solves the problem of motion interference between the fork synchronization link 53 and the steering wheel 70. The fork synchronization link 53 uses a bent structure to form a space to avoid the steering wheel 70, allowing it to bypass the working area of ​​the steering wheel 70 during movement, avoiding mechanical collisions and friction losses, and ensuring the stability and operational reliability of the transport vehicle during cargo lifting.

[0100] The traditional hydraulic drive mechanism relies on mechanical limit or sensor feedback, and the height control error of the rear frame 20 is high, resulting in low height adjustment accuracy. In order to improve the position accuracy of the rear frame 20 when it descends to the low position, Figure 10 for Figure 9 The structure explosion diagram of the lifting power device 50 is shown. Figure 7 、 Figure 8 、 Figure 9 and Figure 10As shown, the motor drive assembly 51 includes a motor 511, a reducer 512, and a proximity sensor 513. The first side of the reducer 512 is in driving connection with the motor 511. An output shaft 5121 is provided on the second side of the reducer 512. The output shaft 5121 serves as the drive shaft of the motor drive assembly 51 and is connected to the first end of the swing arm 52. The proximity sensor 513 is provided on the second side of the reducer 512 at a position corresponding to the first angle. When the swing arm 52 rotates to the first angle, the proximity sensor 513 senses a position sensing signal triggered by the swing arm 52, and the motor 511 stops rotating in response to the position sensing signal.

[0101] Proximity sensor 513 may be an inductive or capacitive sensor, but is not limited thereto. It is installed at a distance from the physical position of swing arm 52 at the first angle. When swing arm 52 rotates to the first angle, its second end enters the detection area of ​​proximity sensor 513, triggering a position sensing signal. Upon receiving the position sensing signal, motor 511 stops rotating.

[0102] Since the proximity sensor 513 directly detects the physical position of the swing arm 52, the error problem that occurs when the lowering position of the rear frame 20 is controlled solely by the algorithm to control the number of rotations of the motor 511 can be avoided, thereby improving the position control accuracy of the rear frame 20 in the lowered state.

[0103] In some embodiments, the motor 511 may be a servo motor, and the reducer 512 may be a planetary reducer. Of course, the reducer 512 may also adopt other structural forms, such as a parallel axis reducer or an angular reducer.

[0104] In some embodiments, the bottom portion of the second side of the reducer 512 corresponds to the first angle, and the proximity sensor 513 is disposed at the bottom portion of the second side of the reducer 512. In some embodiments, the top portion of the second side of the reducer 512 corresponds to the second angle, but this is not limiting. Alternatively, a position other than the top and bottom portion of the second side of the reducer 512 may correspond to the second angle.

[0105] To improve the positioning accuracy of the rear frame 20 when it reaches the raised position, the motor 511 includes a motor body and an encoder. The encoder is used to record the number of rotations of the motor body. When the number of rotations reaches the commanded number of rotations (calculated based on the rear frame 20 raised height input by the user), the motor body stops rotating.

[0106] For example, when the rear frame 20 is raised to the high position, by recording the number of revolutions of the motor body, it is possible to determine whether the angular position of the swing arm 52 has reached the second angle. If so, the motor body stops rotating.

[0107] In the embodiment of this solution, on the one hand, the lifting height of the rear frame 20 is controlled by an encoder, thereby improving the position accuracy of the frame when it is raised to a high position; on the other hand, the encoder is built into the motor 511, and relies on it to record the number of rotations of the motor body to control the lifting of the rear frame 20, eliminating the end sensor that records the number of rotations of the motor in the traditional solution, thereby improving the integration of the transport vehicle and increasing the reliability of the system.

[0108] In some embodiments, the motor 511 also includes a brake. When power is off, the brake locks the motor shaft to restrict its rotation; when power is on, the brake is released. Compared to traditional hydraulic drive mechanisms, this solution maintains the rear frame 20 in the high position through the locking action of the brake, resulting in lower energy consumption.

[0109] Figure 11 for Figure 3 The enlarged view of N in Figure 11 As shown, the lifting power device 50 also includes a joint bearing 54 and a limit member 55; the joint bearing 54 includes an inner ring and an outer ring, and the outer surface of the inner ring is rotatably connected to the inner surface of the outer ring; one end of the fork synchronization link 53 is provided with a bearing chamber, the outer ring is provided in the bearing chamber, and the inner ring is provided at the second end of the swing arm 52, so that one end of the fork synchronization link 53 and the second end of the swing arm 52 are hinged; the limit member 55 is used to limit the outer ring to keep it in the bearing chamber.

[0110] This embodiment utilizes a multi-link design that organically combines a slider-crank mechanism with a first parallelogram mechanism. This results in a high number of components and a wide tolerance chain. The fork synchronization link 53 is connected to the swing arm 52 via a spherical bearing 54, allowing for a high degree of freedom of movement to accommodate the wide tolerance chain, thereby improving the operational stability of the lifting power unit 50.

[0111] In addition, when the transport truck is lifting heavy objects or traveling on uneven roads, the rear frame 20 is subjected to a large impact force. In the embodiment of this solution, on the one hand, the fork synchronization link 53 is connected to the swing arm 52 via the joint bearing 54. The impact force of the rear frame 20 is first transmitted to the fork synchronization link 53. The fork synchronization link 53 rotates with the swing arm 52 via the joint bearing 54, thereby reducing the impact force of the rear frame 20 on the swing arm 52, and further reducing the impact force of the swing arm 52 on the motor drive assembly 51, which is beneficial for protecting the motor drive assembly 51 and improving the service life of the transport truck. On the other hand, each hinge point in the first parallelogram mechanism and the crank slider mechanism has a small gap (a gap caused by the manufacturing process). The impact force of the rear frame 20 can also be "absorbed" and partially reduced by the gap at these hinge points, thereby reducing the impact force of the swing arm 52 on the motor drive assembly 51, which is beneficial for protecting the motor drive assembly 51 and improving the service life of the transport truck.

[0112] The limiting member 55 may be a retaining spring to limit the spherical bearing 54 to the bearing chamber.

[0113] In order to provide effective support to the rear frame 20, Figure 12 for Figure 3 The schematic diagram of the structure of the hidden part of the rear frame 20 of the transport vehicle is shown in FIG. Figure 3 、 Figure 4 、 Figure 5 and Figure 12 As shown, the transport vehicle further includes a first load-bearing wheel assembly 60A, which includes a first wheel frame 61A, a first wheel group 62A and a first transmission link 63A; wherein the first wheel frame 61A is sequentially provided with a first connecting end 611A, a second connecting end 612A and a third connecting end 613A; the first wheel group 62A is provided at the first connecting end 611A of the first wheel frame 61A; the rear frame 20 serves as a second frame and is also connected to the second connecting end of the first wheel frame 61A 612A is hinged, and the first wheel frame 61A and the first connecting rod 30A are both used as connecting rods connected to the second frame. The first transmission link 63A is hinged to the third connecting end 613A of the first wheel frame 61A and the first connecting rod 30A respectively, so that the second frame, the first wheel frame 61A, the first connecting rod 30A and the first transmission link 63A form a hinged four-bar mechanism; wherein the positions at which the first connecting rod 30A is hinged to the rear frame 20 and the first transmission link 63A are different (see Figure 5The rear frame 20 and the first connecting rod 30A are hinged at hinge point three P3, and the first transmission link 63A and the first connecting rod 30A are hinged at hinge point five P5, and P3 and P5 are at different positions of the first connecting rod 30A. Under the swing of the first connecting rod 30A, the first connecting rod 30A can push the first wheel frame 61A to rotate around the second connecting end 612A as the center point through the first transmission link 63A. When the rear frame 20 is in a high position, the first wheel group 62A is lowered relative to the rear frame 20 to support the rear frame 20.

[0114] When the rear frame 20 is in the low position, the first wheel set 62A forms a support with the ground.

[0115] When the rear frame 20 is raised from the lowered position to the upper position, the swing arm 52 rotates from the first angle to the second angle. The first connecting link 30A swings in response to the lifting force of the rear frame 20. The swinging of the first connecting link 30A pushes the third connecting end 613A of the first wheel frame 61A via the first transmission link 63A. Because the second connecting end 612A is hinged to the rear frame 20, the first wheel frame 61A rotates about the second connecting end 612A. Simultaneously, because the first wheel assembly 62A is supported on the ground, it only moves horizontally. The first wheel assembly 62A reversely supports the upward movement of the second connecting end 612A, thereby providing support for the rear frame 20. This support is compatible with the lifting of the rear frame 20 by the first parallelogram mechanism, allowing the rear frame 20 to remain horizontal during the lift from the lowered position to the upper position. Through the linkage between the first transmission link 63A and the first connecting rod 30A, during the lifting process of the rear frame 20, the first wheel set 62A is gradually lowered compared to the rear frame 20 and maintains support on the ground, so that the first wheel set 62A supports the rear frame 20 in the high position.

[0116] In the specific implementation, Figure 13 for Figure 3 The structure of the rear frame 20 of the transport vehicle is shown Figure 1 , Figure 14 for Figure 3 The structure of the rear frame 20 of the transport vehicle is shown Figure 2 ,like Figure 13 and Figure 14 As shown, the rear frame 20 includes: a cargo stand 21 , a first cargo fork 22A and a second cargo fork 22B. The first cargo fork 22A and the second cargo fork 22B are arranged at intervals and are respectively connected to the bottom of the cargo stand 21 .

[0117] like Figure 3 、 Figure 12 、 Figure 13 and Figure 14As shown, the second connecting end 612A of the first wheel frame 61A is rotatably provided on the first fork 22A. When the rear frame 20 is in a high position, the first wheel assembly 62A is lowered relative to the first fork 22A to support the first fork 22A.

[0118] like Figure 3 、 Figure 12 、 Figure 13 and Figure 14 As shown, the transport vehicle further includes: a third connecting rod 30B, a fourth connecting rod 40B and a second load-bearing wheel assembly 60B; wherein, the front frame 10 serves as a first frame, which is hinged to the third connecting rod 30B and the fourth connecting rod 40B respectively; the rear frame 20 serves as a second connecting rod, which is hinged to the third connecting rod 30B and the fourth connecting rod 40B respectively, and the first frame, the third connecting rod 30B, the fourth connecting rod 40B and the second connecting rod form a second parallelogram mechanism; the lifting power device 50 is also used to provide lifting power for the rear frame 20, so that the third connecting rod 30B and the fourth connecting rod 40B rotate synchronously, and the rear frame 20 is lifted from a low position to a high position.

[0119] The second load-bearing wheel assembly 60B includes: a second wheel frame 61B, a second wheel group 62B and a second transmission link 63B; wherein, the second wheel frame 61B is sequentially provided with a fourth connection end 611B, a fifth connection end 612B and a sixth connection end 613B, the second wheel group 62B is provided at the fourth connection end 611B of the second wheel frame 61B, the fifth connection end 612B of the second wheel frame 61B is rotatably provided on the second fork 22B, and the second transmission link 63B is rotatably connected to the sixth connection end 613B of the second wheel frame 61B and the third connecting rod 30B respectively; wherein, under the swing of the third connecting rod 30B, the third connecting rod 30B can push the second wheel frame 61B to rotate via the second transmission link 63B, and when the rear frame 20 is in a high position, the second wheel group 62B is lowered relative to the second fork 22B to support the second fork 22B.

[0120] When the rear frame 20 is in the low position, the first wheel set 62A supports the first fork 22A, and the second wheel set 62B supports the second fork 22B.

[0121] When the rear frame 20 is raised from the lowered position to the upper position, the swing arm 52 rotates from the first angle to the second angle, and the first wheel assembly 62A provides stable support for the first fork 22A in the upper position. The third connecting rod 30B swings in response to the lifting force of the rear frame 20. This swinging motion of the third connecting rod 30B pushes the sixth connecting end 613B of the second wheel frame 61B via the second transmission link 63B. Because the fifth connecting end 612B is hinged to the rear frame 20, the second wheel frame 61B rotates about the fifth connecting end 612B. Simultaneously, because the second wheel assembly 62B is supported on the ground, it only moves horizontally. The second wheel assembly 62B reversely supports the upward movement of the fifth connecting end 612B, thereby providing support for the rear frame 20. This support is compatible with the lifting of the rear frame 20 by the second parallelogram mechanism, ensuring that the rear frame 20 remains level when raised from the lowered position to the upper position. Through the linkage relationship between the second transmission link 63B and the third connecting rod 30B, during the lifting process of the rear frame 20, the second wheel set 62B is gradually lowered compared to the rear frame 20 and maintained on the ground, so that the second wheel set 62B supports the second fork 22B in the high state.

[0122] The first wheel set 62A and the second wheel set 62B cooperate to form a stable support for the rear frame 20 in the low position and the high position.

[0123] The first wheel assembly 62A includes a first bracket and two first wheels, which are mounted at either end of the first bracket. The first wheels are hingedly connected to a first connecting end 611A of the first wheel frame 61A. As the first wheel frame 61A rotates, the first bracket rotates relative to the first wheel frame 61A, allowing the two first wheels to adapt to the ground and maintain contact with the ground.

[0124] The second wheel assembly 62B may include a second bracket and two second wheels, the two second wheels being disposed at both ends of the second bracket and being hingedly connected to a fourth connecting end 611B of the second wheel bracket 61B. As the second wheel bracket 61B rotates, the second bracket rotates relative to the second wheel bracket 61B, allowing the two second wheels to adapt to the ground and maintain contact with the ground.

[0125] The first wheel assembly 62A and the second wheel assembly 62B may have different heights. To address this issue, in an embodiment of this solution, at least one of the first transmission connecting rod 63A and the second transmission connecting rod 63B is adjustable in length. When the first wheel assembly 62A and the second wheel assembly 62B do not have the same height, the length of at least one of the first transmission connecting rod 63A and the second transmission connecting rod 63B can be adjusted to bring the first wheel assembly 62A and the second wheel assembly 62B into the same height.

[0126] Combine Figure 5As shown, taking the first transmission link 63A as an example, the first transmission link 63A includes: a rod body 631A, a stud 632A, a self-locking nut 633A and a rod mounting seat 634A, the first end of the rod body 631A and the third connecting end 613A of the first wheel frame 61A are hinged, and the second end of the rod body 631A and the first end of the stud 632A are fixed.

[0127] The first end of the rod mounting base 634A has a socket, and the second end of the stud 632A can be telescopically inserted into the socket of the rod mounting base 634A. The second end of the rod mounting base 634A is hinged to the hinge point 5 P5 where the first transmission link 63A is hinged to the first connecting rod 30A.

[0128] The self-locking nut 633A is threadedly connected to the stud 632A and is located between the rod body 631A and the rod mounting seat 634A. By adjusting the position of the self-locking nut 633A on the stud 632A, the length of the first transmission connecting rod 63A can be adjusted.

[0129] For example, by rotating the self-locking nut 633A toward the rod mounting seat 634A, the self-locking nut 633A can push the rod mounting seat 634A away from the rod body 631A, thereby increasing the length of the rod body 631A and lowering the first wheel assembly 62A.

[0130] For example, if the self-locking nut 633A is rotated away from the rod mounting seat 634A, the self-locking nut 633A approaches the rod body 631A, tending to create a gap between the self-locking nut 633A and the rod mounting seat 634A. Under the load of the rear frame 20, the first wheel assembly 62A pushes the first wheel frame 61A to rotate, thereby driving the rod body 631A and the stud 632A toward the rod mounting seat 634A, causing the second end of the stud 632A to retract into the socket of the rod mounting seat 634A, thereby reducing the length of the rod body 631A and raising the first wheel assembly 62A.

[0131] In some embodiments, the first transmission link 63A further includes: a butterfly spring piece 635A, which is disposed on the stud 632A and located between the self-locking nut 633A and the rod mounting seat 634A, and can further improve the position stability of the self-locking nut 633A on the stud 632A.

[0132] In the embodiment of the present application, the first load-bearing wheel assembly 60A and the second load-bearing wheel assembly 60B on both sides of the bottom of the rear frame 20 of the transporter, and the steering wheel 70 at the bottom of the front frame 10 constitute a three-point support for the transporter, which can form a stable support. The transporter can be suitable for logistics transportation in narrow channel application scenarios.

[0133] The universal wheels 80 can be floating universal wheels, which can be adjusted up and down by spring force at the bottom of the front frame 10. During travel, the first load-bearing wheel assembly 60A, the second load-bearing wheel assembly 60B, and the steering wheel 70 provide three-point support for the transporter. The two floating universal wheels are in contact with the ground, compressing the springs. When encountering uneven road conditions, the spring force allows the floating universal wheels to adjust to the uneven surface at the bottom of the front frame 10, reducing the possibility of slipping caused by the two universal wheels 80 lifting the steering wheel 70.

[0134] Specifically, Figure 15 for Figure 3 The schematic structural diagram of the front frame 10 of the transport vehicle is shown in FIG. Figure 12 and Figure 15 As shown, the front frame 10 includes: a supporting cross plate 11, a first connecting portion 12A, a second connecting portion 13A, a third connecting portion 12B, and a fourth connecting portion 13B. The lifting power device 50 is arranged on the supporting cross plate 11. The first connecting portion 12A and the second connecting portion 13A are sequentially arranged on the supporting cross plate 11 along the height direction of the transport vehicle and are located on one side of the lifting power device 50. The third connecting portion 12B and the fourth connecting portion 13B are sequentially arranged on the supporting cross plate 11 along the height direction of the transport vehicle and are located on the other side of the lifting power device 50.

[0135] like Figure 15 As shown, the front frame 10 further includes: a vertical enclosure plate 14; a supporting cross plate 11 having an inner side proximal to the shelf 21 and an outer side distal to the shelf 21; a first connecting portion 12A, a second connecting portion 13A, a third connecting portion 12B, and a fourth connecting portion 13B disposed on the inner side of the supporting cross plate 11; and the vertical enclosure plate 14 wrapping around the outer side of the supporting cross plate 11. The addition of the vertical enclosure plate 14 not only protects the structure and components inside the supporting cross plate 11 but also improves the overall strength of the front frame 10, making it less susceptible to bending and deformation.

[0136] like Figure 12 、 Figure 13 and Figure 14As shown, the rear frame 20 includes: a fifth connecting portion 23A, a sixth connecting portion 24A, a seventh connecting portion 23B and an eighth connecting portion 24B. The fifth connecting portion 23A and the sixth connecting portion 24A are sequentially arranged on the shelf 21 along the height direction of the transport vehicle, and the seventh connecting portion 23B and the eighth connecting portion 24B are sequentially arranged on the shelf 21 along the height direction of the transport vehicle; the two ends of the first connecting rod 30A are respectively hinged to the first connecting portion 12A and the fifth connecting portion 23A, and the two ends of the second connecting rod 40A are respectively hinged to the second connecting portion 13A and the sixth connecting portion 24A; the two ends of the third connecting rod 30B are respectively hinged to the third connecting portion 12B and the seventh connecting portion 23B, and the two ends of the fourth connecting rod 40B are respectively hinged to the fourth connecting portion 13B and the eighth connecting portion 24B.

[0137] In the above embodiment, the transport vehicle adopts the fork synchronization link 53 as a pull rod. The present embodiment is different from the above embodiment in that the fork synchronization link 53 is a push rod.

[0138] Figure 16 This is a structural diagram of a transport vehicle provided in an embodiment of the present application using another type of fork synchronization link 53. Figure 17 for Figure 16 The cross-sectional structural diagram of the transport vehicle shown in FIG. Figure 18 for Figure 16 The schematic diagram of the structure of the hidden part of the rear frame 20 of the transport vehicle is shown in FIG. Figure 16 、 Figure 17 and Figure 18 As shown, the third position w3 where the fork synchronization link 53 and the rear frame 20 are hinged is higher than the fourth position w4 where the fork synchronization link 53 and the second end of the swing arm 52 are hinged, so that the fork synchronization link 53 is a push rod.

[0139] When the motor drive assembly 51 drives the swing arm 52 to rotate, the fork synchronization link 53 applies thrust to the rear frame 20, thereby lifting the rear frame 20. Compared to a structure in which the fork synchronization link 53 is a pull rod and tilted downward (the first position w1 at which the fork synchronization link 53 is hinged to the rear frame 20 is lower than the second position w2 at which it is hinged to the second end of the swing arm 52), in this embodiment, the fork synchronization link 53 tilts upward (the third position w3 at which the fork synchronization link 53 is hinged to the rear frame 20 is higher than the fourth position w4 at which the fork synchronization link 53 is hinged to the second end of the swing arm 52), and is further away from the steering wheel 70. This push rod structure avoids potential conflict between the motion path and the steering wheel 70 caused by the pull rod layout, thereby ensuring that the steering wheel 70 does not affect the structural design of the fork synchronization link 53.

[0140] In practice, the fork synchronization link 53 can be a straight rod. Compared with a bent rod, the fork synchronization link 53 is less likely to bend and deform when the rear frame 20 is lifted, thereby improving the stability of the rear frame 20 when lifting.

[0141] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A transport vehicle, characterized in that: include: Front frame (10); rear frame (20); a first connecting rod (30A); A second connecting rod (40A); wherein the front frame (10) serves as a first frame and is hinged to the first connecting rod (30A) and the second connecting rod (40A) respectively; the rear frame (20) serves as a first connecting rod and is hinged to the first connecting rod (30A) and the second connecting rod (40A) respectively, and the first frame, the first connecting rod (30A), the second connecting rod (40A) and the first connecting rod form a first parallelogram mechanism; A lifting power device (50) is provided on the front frame (10) and is used to provide lifting power for the rear frame (20), so that the first connecting rod (30A) and the second connecting rod (40A) rotate synchronously, thereby lifting the rear frame (20) from a low position to a high position.

2. The transport vehicle according to claim 1, wherein: Also includes: The first load-bearing wheel assembly (60A) comprises: a first wheel frame (61A), a first wheel set (62A) and a first transmission connecting rod (63A); wherein, The first wheel frame (61A) is sequentially provided with a first connecting end (611A), a second connecting end (612A) and a third connecting end (613A); The first wheel set (62A) is arranged at the first connecting end (611A) of the first wheel frame (61A); The rear frame (20) serves as a second frame and is also hinged to the second connecting end (612A) of the first wheel frame (61A), and the first wheel frame (61A) and the first connecting rod (30A) are both used as connecting rods connected to the second frame. The first transmission connecting rod (63A) is respectively hinged to the third connecting end (613A) of the first wheel frame (61A) and the first connecting rod (30A), so that the second frame, the first wheel frame (61A), the first connecting rod (30A) and the first transmission connecting rod (63A) form a hinged four-bar mechanism; The hinged positions of the first connecting rod (30A), the rear frame (20) and the first transmission connecting rod (63A) are different. When the first connecting rod (30A) swings, the first connecting rod (30A) can push the first wheel frame (61A) to rotate via the first transmission connecting rod (63A). When the rear frame (20) is in a high position, the first wheel set (62A) is lowered relative to the rear frame (20) to support the rear frame (20).

3. The transport vehicle according to claim 1 or 2, characterized in that: The lifting power device (50) comprises: a motor drive assembly (51), a swing arm (52) and a fork synchronization connecting rod (53); The motor drive assembly (51) is arranged on the front frame (10), the first end of the swing arm (52) is connected to the drive shaft of the motor drive assembly (51), so that the drive shaft of the motor drive assembly (51) can drive the swing arm (52) to swing along the axis of the drive shaft, and the two ends of the fork synchronization link (53) are respectively hinged to the second end of the swing arm (52) and the rear frame (20), wherein the front frame (10) serves as the first frame, the rear frame (20) serves as a slider, and the first frame (10), the swing arm (52), the fork synchronization link (53) and the slider form a crank slider mechanism; When the swing arm (52) rotates to a first angle, the rear frame (20) is in the low position; when the swing arm (52) rotates to a second angle, the swing arm (52) drives the rear frame (20) to be lifted to the high position via the fork synchronization link (53).

4. The transport vehicle according to claim 3, characterized in that: The lifting power device (50) further includes: a joint bearing (54) and a limiting member (55); The spherical bearing (54) comprises an inner ring and an outer ring, wherein the outer surface of the inner ring and the inner surface of the outer ring are rotatably connected; A bearing chamber is provided at one end of the fork synchronization link (53), the outer ring is provided in the bearing chamber, and the inner ring is provided at the second end of the swing arm (52), so that one end of the fork synchronization link (53) and the second end of the swing arm (52) are hinged; The limiting member (55) is used to limit the outer ring so that it is retained in the bearing chamber.

5. The transport vehicle according to claim 3, wherein: The motor drive assembly (51) includes: a motor (511), a reducer (512) and a proximity sensor (513); A first side of the reducer (512) is in transmission connection with the motor (511), and an output shaft (5121) is provided on a second side of the reducer (512). The output shaft (5121) serves as a drive shaft of the motor drive assembly (51) and is connected to a first end of the swing arm (52); The proximity sensor (513) is arranged at a position corresponding to the first angle on the second side of the reducer (512), so that when the swing arm (52) rotates to the first angle, the proximity sensor (513) senses the swing arm (52) triggering a position sensing signal, and the motor (511) stops rotating according to the position sensing signal.

6. The transport vehicle according to claim 5, characterized in that: The motor (511) comprises: a motor body and an encoder; The encoder is used to record the number of rotations of the motor body, and the motor body stops rotating after the number of rotations reaches a command number of rotations, and the command number of rotations is calculated based on the rising height of the rear frame (20) input by the user.

7. The transport vehicle according to claim 3, characterized in that: A first position (w1) where the fork synchronization link (53) and the rear frame (20) are hinged is lower than a second position (w2) where the fork synchronization link (53) and the second end of the swing arm (52) are hinged, so that the fork synchronization link (53) is a pull rod.

8. The transport vehicle according to claim 7, wherein: Also includes: A steering wheel (70) is provided at the bottom of the front frame (10); The fork synchronous connecting rod (53) includes a first rod segment (531) and a second rod segment (532), wherein the first end of the first rod segment (531) is hinged to the rear frame (20), the first end of the second rod segment (532) is hinged to the second end of the swing arm (52), and the second end of the first rod segment (531) and the second end of the second rod segment (532) are bent and connected in a direction away from the steering wheel (70), thereby forming a space to avoid the steering wheel (70).

9. The transport vehicle according to claim 3, characterized in that: The third position (w3) at which the fork synchronization link (53) and the rear frame (20) are hinged is higher than the fourth position (w4) at which the fork synchronization link (53) and the second end of the swing arm (52) are hinged, so that the fork synchronization link (53) is a push rod.

10. The transport vehicle according to claim 2, wherein: The rear frame (20) comprises: a cargo shelf (21), a first cargo fork (22A) and a second cargo fork (22B), wherein the first cargo fork (22A) and the second cargo fork (22B) are arranged at intervals and are respectively connected to the bottom of the cargo shelf (21); The second connecting end (612A) of the first wheel frame (61A) is rotatably arranged on the first fork (22A), and when the rear frame (20) is in a high position, the first wheel set (62A) is lowered relative to the first fork (22A) to support the first fork (22A); a third connecting rod (30B) and a fourth connecting rod (40B); wherein the front frame (10) serves as a first frame and is respectively hinged to the third connecting rod (30B) and the fourth connecting rod (40B); the rear frame (20) serves as a second connecting rod and is respectively hinged to the third connecting rod (30B) and the fourth connecting rod (40B), and the first frame, the third connecting rod (30B), the fourth connecting rod (40B) and the second connecting rod form a second parallelogram mechanism; the lifting power device (50) is also used to provide lifting power for the rear frame (20), so that the third connecting rod (30B) and the fourth connecting rod (40B) rotate synchronously, and the rear frame (20) is lifted from a low position to a high position; The second load-bearing wheel assembly (60B) comprises: a second wheel frame (61B), a second wheel set (62B) and a second transmission connecting rod (63B); wherein, The second wheel frame (61B) is provided with a fourth connecting end (611B), a fifth connecting end (612B) and a sixth connecting end (613B) in sequence; the second wheel set (62B) is provided at the fourth connecting end (611B) of the second wheel frame (61B); the fifth connecting end (612B) of the second wheel frame (61B) is rotatably provided at the second fork (22B); and the second transmission connecting rod (63B) is rotatably connected to the sixth connecting end (613B) of the second wheel frame (61B) and the third connecting rod (30B) respectively; Wherein, under the swing of the third connecting rod (30B), the third connecting rod (30B) can push the second wheel frame (61B) to rotate via the second transmission connecting rod (63B), and when the rear frame (20) is in a high position, the second wheel set (62B) is lowered relative to the second fork (22B) to support the second fork (22B).

11. The transport vehicle according to claim 10, wherein: At least one of the first transmission link (63A) and the second transmission link (63B) is adjustable in length.

12. The transport vehicle according to claim 10, wherein: The front frame (10) comprises: a supporting transverse plate (11), a first connecting portion (12A), a second connecting portion (13A), a third connecting portion (12B), and a fourth connecting portion (13B); the lifting power device (50) is arranged on the supporting transverse plate (11); the first connecting portion (12A) and the second connecting portion (13A) are sequentially arranged on the supporting transverse plate (11) along the height direction of the transport vehicle and are located on one side of the lifting power device (50); the third connecting portion (12B) and the fourth connecting portion (13B) are sequentially arranged on the supporting transverse plate (11) along the height direction of the transport vehicle and are located on the other side of the lifting power device (50); The rear frame (20) comprises: a fifth connecting portion (23A), a sixth connecting portion (24A), a seventh connecting portion (23B) and an eighth connecting portion (24B); the fifth connecting portion (23A) and the sixth connecting portion (24A) are sequentially arranged on the backstop (21) along the height direction of the transport vehicle; the seventh connecting portion (23B) and the eighth connecting portion (24B) are sequentially arranged on the backstop (21) along the height direction of the transport vehicle; The two ends of the first connecting rod (30A) are respectively hinged to the first connecting portion (12A) and the fifth connecting portion (23A), and the two ends of the second connecting rod (40A) are respectively hinged to the second connecting portion (13A) and the sixth connecting portion (24A); The two ends of the third connecting rod (30B) are respectively hinged to the third connecting portion (12B) and the seventh connecting portion (23B), and the two ends of the fourth connecting rod (40B) are respectively hinged to the fourth connecting portion (13B) and the eighth connecting portion (24B).

13. The transport vehicle according to claim 12, wherein: The front frame (10) further includes: a vertical enclosure plate (14); The supporting transverse plate (11) has an inner side close to the shelf backstop (21) and an outer side away from the shelf backstop (21); The first connecting portion (12A), the second connecting portion (13A), the third connecting portion (12B) and the fourth connecting portion (13B) are arranged on the inner side of the supporting transverse plate (11) close to the shelf (21); The enclosure vertical plate (14) is wrapped around the outer side of the supporting horizontal plate (11) away from the shelf (21).

Images