Pallet truck up-down floating locking adjusting mechanism, height locking method and assembly system

Abstract

The invention relates to the technical field of logistics machinery assembly, in particular to an up-down floating locking adjusting mechanism of a pallet truck, a pallet fork height locking method using the mechanism and a pallet truck assembly system comprising the mechanism. The mechanism comprises an adjusting bolt, the side wall of which is provided with six crossed through holes; the top of the fixed sleeve is provided with four semicircular grooves which are uniformly distributed in the circumferential direction; and one end of a bolt spring of the bolt assembly is fixed in the dislocation hole, and a main body is bent to provide bidirectional anti-loosening torsion. Lifting is achieved by rotating the adjusting bolt, and the bolt assembly is inserted for locking after small-angle rotation is aligned with the hole groove. The rotating arm assembly and the adjusting bolt make contact all the time and move synchronously. The problems that vehicle bottom assembling operation is difficult and vibration loosening occurs are solved, and efficient anti-loosening locking is achieved.

Description

Technical Field

[0001] This invention relates to the field of logistics machinery assembly technology, and in particular to a pallet truck's up-and-down floating locking adjustment mechanism, a fork height locking method using the mechanism, and a pallet truck assembly system including the mechanism. Background Technology

[0002] like Figure 11 As shown, in the pallet truck assembly process, after the vehicle body assembly and fork assembly are assembled, the swing arm assembly to which the fork assembly belongs will continuously press against the fixed pad installed at the bottom of the vehicle body assembly. Due to the existence of component machining tolerances and cumulative assembly errors, the fixed pad needs to have a certain range of vertical floating adjustment capability to ensure that the contact surface between the swing arm assembly and the fixed pad reaches an ideal fit.

[0003] The current industry standard involves inserting multiple layers of metal or polymer shims into the assembly gap between the fixed shim and the vehicle body assembly. The actual support height of the fixed shim is adjusted manually by adding or removing shims. While this adjustment method is structurally simple, it has revealed several operational bottlenecks in actual production line applications: First, the adjustment process requires operators to enter a narrow space with a height of less than 500 mm at the bottom of the vehicle body to disassemble and assemble the pads in a confined environment. Operators often have to adopt unconventional postures such as lying on their back, curling up, or lying on their side, which is not only physically demanding but also prone to causing muscle strain. Secondly, the working environment under the vehicle is dimly lit, and the hydraulic lines, braking mechanism and other components obstruct the view, making it difficult to guarantee the positioning accuracy of the pad. Repeated trial installations and adjustments are often required, and a single adjustment can take more than 30 minutes. In addition, there is a risk of mechanical collision when vehicles move between assembly line stations, and operators face the safety hazard of being squeezed by moving equipment when working under the vehicle.

[0004] More importantly, this technology has a functional defect: the pad assembly only provides static support through friction and cannot achieve active locking. When the pallet truck is subjected to continuous vibration loads during transportation or lifting operations, the pad is prone to slight displacement or even loosening, resulting in an impact gap between the boom assembly and the fixed pad, causing abnormal metal-on-metal collision noises. Long-term operation will accelerate the wear of the boom hinge points and shorten the life of critical components.

[0005] In order to maintain assembly accuracy, the undercarriage adjustment work needs to be repeated frequently during later maintenance, which further increases maintenance costs.

[0006] Therefore, developing an integrated floating adjustment mechanism that can be operated from above the vehicle body and integrates height adjustment and mechanical locking functions has become an urgent need to solve the current technical pain points. Summary of the Invention

[0007] I. Technical problem 1. When the vehicle body assembly and the fork assembly are assembled, the gasket plate needs to be repeatedly disassembled and assembled in the narrow space under the vehicle, which is time-consuming and dangerous; 2. The gasket plate is only statically supported without locking function, and the vibration of the vehicle can easily cause loosening.

[0008] II. Technical solution In order to solve the above problems, the top of the adjusting bolt is designed to replace the operation under the vehicle, and the pre-tightening torque of the latch spring is used to realize zero loosening under vibration conditions, which fundamentally solves the contradiction between safety and reliability. The specific technical solution is as follows: In a first aspect, the present application provides a floating locking and adjusting mechanism for a pallet car, comprising a vehicle body bottom plate and a fixed sleeve, further comprising: Adjusting bolt, coaxially sleeved in the fixed sleeve, the outer thread is engaged with the inner thread of the fixed sleeve, the top is provided with an internal hexagonal hole, and the side wall is provided with a plurality of through holes; The fixed sleeve is fixedly connected with the vehicle body bottom plate through a fastening nut and a fastening screw, and at least one semicircular groove is formed in the top; The latch assembly comprises a latch core rod and a latch spring sleeved thereon, and the latch core rod can be inserted into the through hole of the adjusting bolt and the aligned hole position of the semicircular groove of the fixed sleeve. Wherein, one end of the latch spring is fixed in the misaligned hole of the latch core rod, and the two-way torque is generated to make the latch core rod tightly adhere to the outer wall of the fixed sleeve.

[0009] Preferably, the side wall of the adjusting bolt is uniformly provided with 6 cross-through holes, and the bottoms of the two opposite through holes are through.

[0010] Preferably, the top of the fixed sleeve is provided with four semicircular grooves which are evenly distributed along the circumference.

[0011] Preferably, the end of the latch core rod is provided with two misaligned mounting holes on the upper and lower sides; the main body of the latch spring is bent to one side of the fixed sleeve, one end is inserted into the misaligned mounting hole, and the other end abuts against the outer surface of the fixed sleeve. When the latch core rod is rotated clockwise or counterclockwise to the critical angle, the latch spring generates a contraction and rebound force.

[0012] Preferably, it further comprises an internal hexagonal wrench which can be inserted into the internal hexagonal hole of the adjusting bolt and drive the adjusting bolt to rise and fall by rotating.

[0013] In a second aspect, the present application provides a fork height locking method of the adjusting mechanism as described in the first aspect, comprising the following steps: S1. Insert the internal hexagonal wrench into the internal hexagonal hole of the adjusting bolt, rotate the adjusting bolt clockwise or counterclockwise, and make it rise or fall to the target height in the fixed sleeve; S2. Small angle rotation adjustment bolt, so that any one of its through holes is aligned with any one of the semicircular grooves on the fixing sleeve grooves are aligned; S3. Insert the latch assembly into the aligned through hole and semicircular groove; S4. Release the latch core rod, and use the torsional force of the latch spring to make it tightly adhere to the outer wall of the fixing sleeve.

[0014] Preferably, in step S2, the small angle rotation lifting displacement is less than 1 / 3 of the diameter of the through hole.

[0015] In a third aspect, the present application also provides a pallet truck assembly system of the adjustment mechanism of the first aspect, comprising: a truck body assembly, the bottom of which is fixed to the truck body bottom plate; a fork assembly, the bottom of which abuts against the adjustment bolt through the swing arm assembly; wherein the swing arm assembly moves synchronously with the adjustment bolt when the adjustment bolt is lifted, and the two always maintain contact.

[0016] Preferably, the lifting operation of the adjustment bolt and the locking operation of the latch assembly are both completed above the truck body assembly.

[0017] Preferably, the fixing sleeve is vertically fixed to the truck body bottom plate through a fastening nut and a fastening screw.

[0018] III. Advantages Firstly, by shifting the adjustment operation position from the bottom of the truck body to above the truck body, the operator can directly stand and operate the hexagonal wrench to complete the height adjustment and locking, completely avoiding the safety risk of traditional crawling operation at the bottom of the truck. The single adjustment time is shortened from more than 30 minutes to 5 minutes, and the efficiency is improved by more than 80%.

[0019] Secondly, the innovative design of the latch assembly generates continuous bidirectional torsional force through the curved structure of the latch spring, so that the latch core rod is always tightly pressed against the outer wall of the fixing sleeve, and even in the case of continuous vibration, it still maintains zero looseness failure, fundamentally solving the problem of impact noise of the swing arm assembly caused by the displacement of the pad.

[0020] In addition, the mechanism realizes the integration of height adjustment and mechanical locking: the threaded engagement of the adjustment bolt and the fixing sleeve supports stepless precise lifting, and the cooperation of the six intersecting through holes and the four semicircular grooves provides step locking capability, so that the positioning accuracy reaches ±0.5mm, meeting the high-precision assembly requirement.

[0021] More importantly, the swing arm assembly and the adjustment bolt always maintain contact and synchronous floating, eliminating the movement gap while reducing the wear of the hinge point. The actual measurement shows that the service life of the key components is prolonged by more than 2 times.

[0022] Finally, the maintenance convenience obtains the qualitative leap - only needs to flick the latch spring when disassembling can release the locking, does not need the special tool, the maintenance time consumption reduces 50%, greatly reduces the equipment downtime loss. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the whole structure schematic diagram of the adjusting mechanism of the application; Figure 2 It is the section structure schematic diagram of the adjusting mechanism of the application (the final position); Figure 3 It is the section structure schematic diagram of the adjusting mechanism of the application (the intermediate position); Figure 4 It is the section structure schematic diagram of the adjusting mechanism of the application (the initial position); Figure 5 It is the whole structure schematic diagram of the adjusting bolt of the application; Figure 6 It is the whole structure schematic diagram of the fixed sleeve of the application; Figure 7 It is the whole structure schematic diagram of the latch assembly of the application; Figure 8 It is Figure 7 It is the local enlarged view of the misaligned hole of the middle I; Figure 9 It is the front view effect diagram of the adjusting structure of the application after being assembled to the pallet car; Figure 10 It is the bottom effect diagram of the adjusting structure of the application after being assembled to the pallet car; Figure 11 It is the structure schematic diagram of the traditional height adjustment structure of the fixed cushion block; In the figure: 1, adjusting bolt; 2, fixed sleeve; 3, car body bottom plate; 4, fastening screw; 5, latch assembly; 5-1, latch core rod; 5-2, latch spring; 6, fastening nut; 7, inner hexagonal wrench; 8, car body assembly; 9, rotating arm assembly; 10, fixed cushion block; 11, cushion plate; 12, fork assembly; A, B, C, D are all semicircular grooves; a, b, c, d, e, f are all through holes. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the application more clear, the technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0025] Embodiment one: The embodiment provides a floating locking adjusting mechanism on a tray car, which comprises a car body bottom plate 3 and a fixed sleeve 2, and further comprises: an adjusting bolt 1 coaxially sleeved in the fixed sleeve 2, the outer thread of the adjusting bolt 1 is engaged with the inner thread of the fixed sleeve 2, an inner hexagonal hole g is formed in the top of the adjusting bolt 1, and a plurality of through holes a-f are formed in the side wall; the fixed sleeve 2 is fixedly connected with the car body bottom plate 3 through a fastening nut 6 and a fastening screw 4, and at least one semicircular groove A-D is formed in the top of the fixed sleeve 2; a latch assembly 5 comprises a latch core rod 5-1 and a latch spring 5-2 sleeved on the latch core rod 5-1, and the latch core rod 5-1 can be inserted into the aligned hole position of the through holes a-f of the adjusting bolt 1 and the semicircular grooves A-D of the fixed sleeve 2; wherein one end of the latch spring 5-2 is fixed to the misaligned hole of the latch core rod 5-1, and the latch spring 5-2 generates bidirectional torsion force to make the latch core rod 5-1 tightly adhere to the outer wall of the fixed sleeve 2.

[0026] Specifically, referring to Figures 1-4 , the car body bottom plate 3 serves as a mounting base of the floating locking adjusting mechanism, and a load-bearing frame of a car body assembly 8 is welded above the car body bottom plate 3. The fixed sleeve 2 is vertically penetrated through a prefabricated hole of the car body bottom plate 3 through the fastening screw 4, and then the fastening nut 6 is tightened from below, so that the fixed sleeve 2 is rigidly connected with the car body bottom plate 3. The inner thread of the fixed sleeve 2 adopts a M20x1.5 fine tooth specification, and four semicircular grooves A, B, C and D with a depth of 5 mm are milled in the top of the fixed sleeve 2, as shown in Figure 6 , the four semicircular grooves A, B, C and D are evenly distributed at 90 degrees in the circumferential direction.

[0027] As shown in Figure 5 , the adjusting bolt 1 can be made of 40Cr alloy steel, the outer thread of the adjusting bolt 1 is matched with the inner thread of the fixed sleeve 2, a standard 8 mm inner hexagonal hole g is formed in the top center of the adjusting bolt 1, and six intersecting through holes a, b, c, d, e and f with a diameter of 6 mm are drilled in the side wall; wherein the through hole a is coaxially penetrated through the through hole d, the through hole b is coaxially penetrated through the through hole e, the through hole c is coaxially penetrated through the through hole f, and the three groups of through holes are evenly distributed in the circumferential direction. When assembled, the adjusting bolt 1 is screwed into the fixed sleeve 2 from the bottom until the upper end surface of the base of the adjusting bolt 1 is attached to the lower end surface of the fixed sleeve 2.

[0028] As shown in Figure 7 and Figure 8 , the latch assembly 5 is composed of the latch core rod 5-1 and the latch spring 5-2: the latch core rod 5-1 is a cylindrical pin with a diameter of 5.8 mm, and the upper and lower surfaces of the connecting seat are provided with one misaligned hole distributed at an angle and having an axial spacing of 3 mm; the latch spring 5-2 is a torsion spring made of 304 stainless steel wire with a diameter of 1.2 mm, the main body of the latch spring 5-2 is U-shaped, and the two end linear segments are respectively inserted into the misaligned holes of the latch core rod 5-1 for fixation. When the latch core rod 5-1 is not stressed, the U-shaped curved part of the latch spring 5-2 is naturally 0.5 mm away from the outer wall of the fixed sleeve 2, and at this time the latch spring 5-2 stores a pre-tightening torsion force.

[0029] Finally, the hexagonal wrench 7 is placed above the vehicle body assembly 8 for standby, and the size of the hexagonal head matches the hexagonal hole g.

[0030] When height adjustment is needed, the operator stands above the vehicle body and inserts the hexagonal wrench 7 into the hexagonal hole g of the adjusting bolt 1. When the hexagonal wrench 7 is rotated clockwise, the adjusting bolt 1 is driven to descend along the inner hole of the fixed sleeve 2, and vice versa.

[0031] For example, when the support height of the swing arm assembly 9 needs to be lowered, the hexagonal wrench 7 is continuously rotated clockwise until the adjusting bolt 1 is lowered by 15 mm. After reaching the target height, the locking operation needs to be performed: first, observe the relative position of the six through holes of the adjusting bolt 1 and the four semicircular grooves at the top of the fixed sleeve 2, select the hole and groove group with the closest horizontal distance, for example, through hole b and semicircular groove B. At this time, the hexagonal wrench 7 is slowly rotated counterclockwise by about 3 degrees, and the adjusting bolt 1 is raised by about 0.1 mm to align the center of the through hole b with the semicircular groove B. Then, the latch assembly 5 is inserted horizontally into the through hole b and the semicircular groove B, and after releasing the latch rod 5-1, the U-shaped bending part of the latch spring 5-2 is tightly attached to the outer wall of the fixed sleeve 2 due to the torsional recovery, forming a continuous radial compression force.

[0032] When disassembling, one hand pushes the closed end of the latch spring 5-2 outward, and the other hand simultaneously pulls the latch rod 5-1 outward, so that the latch assembly 5 can be quickly pulled out.

[0033] The embodiment transfers the adjustment position to the roof through the design of the adjusting bolt 1, and the roof operation mode reduces the adjustment time from the traditional 30 minutes to 5 minutes. The bending design of the latch spring 5-2 provides bidirectional anti-loose torsional force, and there is no loosening after 200 hours of continuous operation in the vibration test. In addition, the 6-hole 4-groove subgrade structure realizes a positioning accuracy of ±0.1 mm, which is much higher than the ±2 mm error of the pad 11 adjustment, effectively improving the assembly efficiency and safety.

[0034] Embodiment Two: The embodiment provides a fork height locking method using the adjusting mechanism as described in Embodiment One.

[0035] Reference Figures 2-4 In the initial state, the upper end surface of the base of the adjusting bolt 1 is flush with the lower end surface of the fixed sleeve 2, and at this time, the contact position between the swing arm assembly 9 and the bottom of the adjusting bolt 1 is defined as the reference zero position. When the fork assembly 12 needs to be raised by 15 mm for maintenance, the following steps are performed: Step S1, the operator inserts the hexagonal wrench 7 into the hexagonal hole g of the adjusting bolt 1 and rotates it counterclockwise for 10 turns to drive the adjusting bolt 1 to rise by 15 mm to the target height.

[0036] Step S2, fine-tune the rotation angle by using the hex key 7: first rotate counterclockwise by 2 degrees to make the adjusting bolt 1 rise by 0.05 mm, and then observe the distance between the through hole c and the semicircular groove C; if they are not aligned, rotate clockwise by 1 degree until the center lines of the through hole c and the semicircular groove C are coincident, and the overall displacement is about 0.025 mm, which is less than 1 / 3 of the hole diameter.

[0037] Step S3, insert the latch assembly 5 into the aligned passage of the through hole c and the semicircular groove C along the horizontal direction until the latch core rod 5-1 penetrates both of them.

[0038] Step S4, loosen the latch core rod 5-1, and the U-shaped part of the latch spring 5-2 will spring outward under the torsion force to form a stable fitting force on the outer wall of the fixed sleeve 2. When disassembly is needed, push the closed end of the latch spring 5-2 outward by about 2 mm with one hand, and then horizontally pull out the latch assembly 5 with the other hand to release the locking.

[0039] In this embodiment, the control accuracy of small-angle rotation can reach 0.5 degrees, and the locking position error is not more than 0.05 mm with the help of the stepped hole groove; the bending and rebound design of the latch spring 5-2 ensures that the anti-loose force is always perpendicular to the surface of the fixed sleeve 2; the whole roof operation avoids climbing the bottom of the vehicle, and the single-person operation time is only 3-5 minutes. Compared with the traditional shim adjustment method, the efficiency is improved by 85% and the safety risk is eliminated.

[0040] Example Three: This embodiment provides a pallet truck assembly system comprising the adjusting mechanism of Example One.

[0041] Reference Figure 9 and Figure 10 The bottom longitudinal beam of the vehicle body assembly 8 is welded to the vehicle body floor 3, and the fixed sleeve 2 is vertically installed at the center position of the vehicle body floor 3 through the fastening screw 4 and the fastening nut 6, and the verticality error is ≤0.1 degrees. The rotating arm assembly 9 of the fork assembly 12 is connected to the vehicle body assembly 8 in a hinged manner, and the free end is processed into a circular arc surface with a radius of 15 mm, which is always pressed against the bottom plane of the adjusting bolt 1.

[0042] When the adjusting bolt 1 is raised and lowered, the rotating arm assembly 9 floats synchronously in the gapless state of the contact surface, for example, when the adjusting bolt 1 is raised by 10 mm, the rotating arm assembly 9 is raised by 10 mm synchronously.

[0043] All operations are completed above the vehicle body assembly 8: when adjusting the height, the operator stands on the vehicle body platform and rotates the hex key 7 inserted into the hexagonal hole g; when locking, the latch assembly 5 is inserted horizontally from the side of the vehicle body to the aligned hole groove.

[0044] During the lifting of the 500 kg pallet by the fork assembly 12, the rotating arm assembly 9 applies a maximum pressure of 5000 N to the adjusting bolt 1, and at this time the anti-loose structure of the latch assembly 5 still maintains zero displacement.

[0045] This embodiment translates the height variation of the adjustment bolt 1 directly into a precise displacement of the boom assembly 9 and the vertical fixation of the adjustment bolt 1 allows the transmission of the vibration energy of the boom assembly 9 along the thread axis, avoiding lateral impacts. The measured data show that this system reduces the assembly failure rate by 90% and extends the life of the boom assembly 9 from 1 year to 3 years.

[0046] Although the present application has been described in detail with general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of the present application claimed.

Claims

1. A pallet truck vertical floating locking adjustment mechanism, comprising a vehicle body base plate (3) and a fixing sleeve (2), characterized in that, it further comprises... include: Adjusting bolt (1) is coaxially sleeved inside the fixed sleeve (2), and its external thread engages with the internal thread of the fixed sleeve (2). It has an internal hexagonal hole (g) at the top and multiple through holes (a~f) on the side wall. The fixed sleeve (2) is fixedly connected to the vehicle body floor plate (3) by fastening nut (6) and fastening screw (4), and at least one semi-circular groove (A~D) is opened on the top. The pin assembly (5) includes a pin core (5-1) and a pin spring (5-2) sleeved thereon. The pin core (5-1) can be inserted into the alignment hole of the through hole (a~f) of the adjusting bolt (1) and the semi-circular groove (A~D) of the fixing sleeve (2). One end of the pin spring (5-2) is fixed to the misaligned hole of the pin core (5-1), generating bidirectional torque to make the pin core (5-1) tightly adhere to the outer wall of the fixing sleeve (2).

2. The pallet cart vertical floating locking adjustment mechanism according to claim 1, characterized in that: The adjusting bolt (1) has 6 intersecting holes (a to f) evenly opened on its side wall, and the bottoms of the two holes (a to f) that are directly opposite each other are connected.

3. The pallet cart vertical floating locking adjustment mechanism according to claim 1, characterized in that: The top of the fixed sleeve (2) has four semi-circular grooves (A to D) that are evenly distributed along the circumference.

4. The pallet cart vertical floating locking adjustment mechanism according to claim 1, characterized in that: The pin core rod (5-1) has two staggered mounting holes on the upper and lower sides of its end; the main body of the pin spring (5-2) is bent toward the fixed sleeve (2), with one end inserted into the staggered mounting hole and the other end abutting against the outer surface of the fixed sleeve (2); When the pin core (5-1) rotates clockwise or counterclockwise to the critical angle, the pin spring (5-2) generates a contraction and rebound force.

5. The pallet cart vertical floating locking adjustment mechanism according to claim 1, characterized in that: It also includes an internal hex wrench (7) that can be inserted into the internal hex hole (g) of the adjusting bolt (1) and the adjusting bolt (1) is raised or lowered by rotation.

6. A fork height locking method using the adjusting mechanism as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Insert the hex wrench (7) into the hex socket (g) of the adjusting bolt (1) and rotate the adjusting bolt (1) clockwise or counterclockwise to raise or lower it to the target height within the fixed sleeve (2); S2. Rotate the adjusting bolt (1) at a small angle so that any of its through holes (a~f) aligns with any half-circular groove (A~D) on the fixed sleeve (2); S3. Insert the pin assembly (5) into the aligned through holes (a~f) and semi-circular grooves (A~D); S4. Release the pin core (5-1) and use the torque of the pin spring (5-2) to make it stick tightly to the outer wall of the fixed sleeve (2).

7. The fork height locking method according to claim 6, characterized in that: In step S2, the lifting displacement of the small-angle rotation is less than 1 / 3 of the diameter of the through hole (a~f).

8. A pallet truck assembly system comprising the adjusting mechanism according to any one of claims 1-5, comprising: The vehicle body assembly (8) has a fixed bottom plate (3) for the vehicle body; The fork assembly (12) abuts against the bottom of the adjusting bolt (1) via the swing arm assembly (9); wherein the swing arm assembly (9) moves synchronously with the adjustment bolt (1) as it rises and falls, and the two always remain in contact.

9. The pallet truck assembly system according to claim 8, characterized in that: The lifting and lowering operation of the adjusting bolt (1) and the locking operation of the pin assembly (5) are both completed above the vehicle body assembly (8).

10. The pallet truck assembly system according to claim 8, characterized in that: The fixing sleeve (2) is vertically fixed to the vehicle body floor plate (3) by fastening nuts (6) and fastening screws (4).

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