An automatic control system for a stand-on reach truck

Abstract

This invention relates to the technical field of stand-on reach trucks, specifically an automatic control system for a stand-on reach truck. It includes a frame, a drive mechanism, and a control system. A pair of load-bearing wheel assemblies are mounted on a pair of front legs of the frame. The drive mechanism includes an L-shaped drive axle, a drive axle shaft, an auxiliary wheel assembly, and a drive wheel assembly. The control system includes a hydraulic system and a cylinder adjustment mechanism. The hydraulic system includes a solenoid valve, a hydraulic multi-way valve, a controller, an oil pump motor, and a hydraulic pump. Therefore, the drive mechanism of this invention is connected to the frame via the drive axle shaft. The L-shaped drive axle, i.e., the auxiliary wheel assembly and the drive wheel assembly, can rotate appropriately around the drive axle shaft. This allows the entire drive mechanism to adjust appropriately according to road conditions. Simultaneously, the reliable hydraulic system can precisely control the force on the drive wheel assembly and the auxiliary wheel assembly, automatically adjusting their states according to road conditions and forming feedback regulation.

Description

Technical Field

[0001] This invention relates to the technical field of stand-on reach trucks, specifically an automatic control system for the body of a stand-on reach truck. Background Technology

[0002] The wheel system of a stand-on reach forklift typically consists of drive wheels, load-bearing wheels, and auxiliary wheels. Currently, the drive wheels and auxiliary wheels are generally rigidly connected to the chassis and cannot be adjusted. Even if adjustment mechanisms exist, they are simple mechanical adjustments that cannot precisely control the stress on the drive and auxiliary wheels. On slopes or uneven surfaces, the drive wheels can easily become suspended or slip, causing the vehicle to malfunction. Furthermore, the driver's standing platform in the cab is currently rigidly connected, resulting in a bumpy ride without shock absorption, leading to discomfort and fatigue during long periods of driving. Summary of the Invention

[0003] To address the problems mentioned in the background art, this invention provides an automatic control system for a stand-on reach truck, which can precisely control the force on the drive wheels and auxiliary wheels, and automatically adjust the state of the drive wheel assembly and auxiliary wheel assembly according to road conditions, effectively ensuring the safety and reliability of the mechanism.

[0004] The specific technical solution of the present invention is as follows: an automatic control system for a stand-on reach truck body, comprising a frame 1, a drive mechanism and a control system;

[0005] A pair of load-bearing wheel assemblies 12 are mounted on a pair of front legs 11 of the frame 1.

[0006] The drive mechanism includes an L-shaped drive axle 21, a drive axle shaft 22, an auxiliary wheel assembly 23, and a drive wheel assembly 24, with the drive wheel assembly 24 connected to the output shaft of the drive motor 25;

[0007] The L-shaped drive axle 21 is arranged at the bottom of the rear of the frame 1, and the horizontal part of the L-shaped drive axle 21 is parallel to the lateral arrangement direction of the frame 1. The drive axle shaft 22 passes through the horizontal part of the L-shaped drive axle 21 longitudinally through the bearing seat and is mounted on the frame 1 through a pair of shaft fixing seats 26. The drive wheel assembly 24 and the auxiliary wheel assembly 23 are respectively mounted on the horizontal parts of the L-shaped drive axle 21 on both sides of the drive axle shaft 22, so that the auxiliary wheel assembly 23 and the drive wheel assembly 24 are located on the lateral sides of the rear of the frame 1.

[0008] The control system includes a hydraulic system and a cylinder adjustment mechanism.

[0009] The hydraulic cylinder adjusting mechanism includes a hydraulic cylinder support 31, a pair of hydraulic cylinders 32, a pressure spring 33, and a hydraulic cylinder connecting seat 34. Each hydraulic cylinder is equipped with a pressure testing valve 322 via a pressure testing connector 321.

[0010] The cylinder connecting seat 34 and the auxiliary wheel assembly 23 are installed and connected. The cylinder support 31 is fixedly installed on the corresponding frame 1 above the cylinder connecting seat 34. A pair of cylinders 32 are vertically installed between the cylinder support 31 and the cylinder connecting seat 34. The pressure spring 33 is vertically installed and limited between the cylinder support 31 and the cylinder connecting seat 34.

[0011] The hydraulic system includes a solenoid valve 41, a hydraulic multi-way valve 42, a controller 43, an oil pump motor 44, and a hydraulic oil pump 45;

[0012] The operation of the oil pump motor 44 causes the hydraulic oil pump 45 to generate oil pressure. The hydraulic oil from the hydraulic oil pump 45 is delivered to a pair of oil cylinders 32 via the hydraulic multi-way valve 42. A pair of pressure testing valves 322 on the pair of oil cylinders 32 monitor the oil pressure and transmit the signal to the controller 43 via the solenoid valve 41. The controller 43 controls the speed of the oil pump motor 44, and then controls the pressure of the pair of oil cylinders 32 by controlling the hydraulic multi-way valve 42. This causes the oil cylinder adjustment mechanism to exert a force on the auxiliary wheel assembly 23, so that the auxiliary wheel assembly 23 and the drive wheel assembly 24 rotate around the drive axle shaft 22 until the rated pressure set by the control system is reached.

[0013] Furthermore, the hydraulic system also includes a lifting cylinder control system and a balance valve 46. The lifting cylinder control system is used to realize the lifting function of the forklift lifting cylinder. The balance valve 46 balances the pressure of a pair of cylinders 32. The solenoid valve 41 is a full proportional solenoid valve.

[0014] Furthermore, the drive motor 25 is installed at the upper end of the vertical part of the L-shaped drive axle 21, and the drive wheel assembly 24 is installed on the outside of the vertical part of the L-shaped drive axle 21, so that the drive wheel assembly 24 is connected to the output shaft of the drive motor 25, and the auxiliary wheel assembly 23 is installed at the horizontal extension end of the L-shaped drive axle 21 through the hydraulic cylinder connecting seat 34.

[0015] Furthermore, the cylinder connecting seat 34 and the cylinder support 31 have the same structure, including a horizontal connecting plate 341, a pair of cylinder connecting lugs 342 and a step column 343. The step column 343 stands upright in the middle of the upper end of the connecting plate 341. The pair of cylinder connecting lugs 342 are symmetrically arranged on the connecting plates 341 at both ends of the step column 343. The connecting plate 341 of the cylinder connecting seat 34 is arranged horizontally and connected to the auxiliary wheel assembly 23. The connecting plate of the cylinder support 31 is rotated 180° to be arranged horizontally and is fixedly connected to the frame 1, so that the pair of cylinders 32 are installed vertically through the cylinder connecting lugs, and the pressure spring 33 is installed vertically and limitedly through the step column 343.

[0016] Furthermore, each of the hydraulic cylinders has a piston rod lug 323 at the upper end of the piston rod and a cylinder lug 324 at the lower end of the cylinder barrel. The piston rod lug 323 and the cylinder lug 324 are respectively connected to the cylinder connecting support pin.

[0017] The beneficial technical effects of the present invention are as follows:

[0018] This invention discloses an automatic control system for a stand-on reach truck, comprising a frame, a drive mechanism, and a control system. A pair of load-bearing wheel assemblies are mounted on a pair of front legs of the frame. The drive mechanism includes an L-shaped drive axle, a drive axle shaft, an auxiliary wheel assembly, and a drive wheel assembly, with the drive wheel assembly connected to the output shaft of a drive motor. The control system includes a hydraulic system and a cylinder adjustment mechanism. The cylinder adjustment mechanism includes a cylinder support, a pair of cylinders, a pressure spring, and a cylinder connecting seat. Each cylinder is equipped with a pressure testing valve via a pressure testing connector. The hydraulic system includes a solenoid valve, a hydraulic multi-way valve, a controller, a pump motor, and a hydraulic pump. Due to the above structure, the following beneficial technical effects are achieved:

[0019] (1) The drive mechanism is connected to the frame through the drive axle shaft and fixed by a pair of shaft mounting seats. Since the drive wheel assembly and the auxiliary wheel assembly are respectively installed on the horizontal part of the L-shaped drive axle on both sides of the drive axle shaft, the L-shaped drive axle, namely the auxiliary wheel assembly and the drive wheel assembly, can rotate appropriately around the drive axle shaft. Thus, the entire drive mechanism is not rigidly fixed and can be adjusted and changed appropriately according to the road conditions.

[0020] (2) The operation of the hydraulic pump motor of the hydraulic system causes the hydraulic pump to generate oil pressure. The hydraulic oil of the hydraulic pump is delivered to a pair of cylinders through the hydraulic multi-way valve. A pair of pressure measuring valves on the cylinders monitor the oil pressure and transmit the signal to the controller through the solenoid valve. The controller adjusts the speed of the pump motor and then adjusts the pressure of the cylinders through the hydraulic multi-way valve, so that the cylinder adjustment mechanism exerts a force on the auxiliary wheel assembly, realizing the rotation of the auxiliary wheel assembly and the drive wheel assembly around the drive axle shaft to the rated pressure set by the control system. This forms a working cycle and feedback loop.

[0021] (3) While adjusting pressure changes through the hydraulic cylinder, a pressure spring is added. Firstly, the hydraulic cylinder will experience some hydraulic shock during operation due to the hydraulic oil. The pressure spring can increase the buffering and shock absorption effect. Secondly, when encountering uneven road surfaces, the load wheel needs a process to adjust the pressure. At this time, the pressure spring can respond quickly to make a preliminary adjustment, and the ideal effect can be achieved after the pressure is balanced. Finally, when the hydraulic system fails, it can independently play a proper adjustment role, which is equivalent to a double protection.

[0022] (4) Both ends of the cylinder are connected by pins to ensure that they will not jam and can move flexibly within the set range. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the automatic control system for a stand-on reach truck body according to the present invention.

[0024] Figure 2 This is a schematic diagram of the frame structure of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the hydraulic cylinder connecting seat of the present invention.

[0026] Figure 4 This is a schematic diagram of the drive mechanism of the present invention.

[0027] Figure 5 This is a schematic diagram of the L-shaped drive bridge of the present invention.

[0028] Figure 6 This is a schematic diagram of the structure of the new hydraulic cylinder.

[0029] Figure 7 This is a system schematic diagram of the hydraulic system of the present invention.

[0030] The components include: frame 1, a pair of front legs 11, a pair of load-bearing wheel assemblies 12, L-shaped drive axle 21, drive axle shaft 22, auxiliary wheel assembly 23, drive wheel assembly 24, drive motor 25, a pair of shaft fixing seats 26, cylinder support 31, a pair of cylinders 32, pressure spring 33, cylinder connecting seat 34, pressure testing connector 321, pressure testing valve 322, solenoid valve 41, hydraulic multi-way valve 42, controller 43, oil pump motor 44, hydraulic oil pump 45, balance valve 46, connecting plate 341, a pair of cylinder connecting lugs 342, step column 343, piston rod lug 323, and cylinder lug 324. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Example

[0032] See Figure 1 and Figure 2 An automatic control system for a stand-on reach truck includes a frame 1, a drive mechanism, and a control system.

[0033] A pair of load-bearing wheel assemblies 12 are mounted on a pair of front legs 11 of the frame 1, see Figure 4 and Figure 5The drive mechanism includes an L-shaped drive axle 21, a drive axle shaft 22, an auxiliary wheel assembly 23, and a drive wheel assembly 24, with the drive wheel assembly 24 connected to the output shaft of the drive motor 25;

[0034] The L-shaped drive axle 21 is arranged at the bottom of the rear of the frame 1, and the horizontal part of the L-shaped drive axle 21 is parallel to the lateral arrangement direction of the frame 1. The drive axle shaft 22 passes through the horizontal part of the L-shaped drive axle 21 longitudinally through the bearing seat and is mounted on the frame 1 through a pair of shaft fixing seats 26. The drive wheel assembly 24 and the auxiliary wheel assembly 23 are respectively mounted on the horizontal parts of the L-shaped drive axle 21 on both sides of the drive axle shaft 22, so that the auxiliary wheel assembly 23 and the drive wheel assembly 24 are located on the lateral sides of the rear of the frame 1.

[0035] The control system includes a hydraulic system and a cylinder adjustment mechanism.

[0036] The hydraulic cylinder adjusting mechanism includes a hydraulic cylinder support 31, a pair of hydraulic cylinders 32, a pressure spring 33, and a hydraulic cylinder connecting seat 34. Each hydraulic cylinder is equipped with a pressure testing valve 322 via a pressure testing connector 321.

[0037] The cylinder connecting seat 34 and the auxiliary wheel assembly 23 are installed and connected. The cylinder support 31 is fixedly installed on the corresponding frame 1 above the cylinder connecting seat 34. A pair of cylinders 32 are vertically installed between the cylinder support 31 and the cylinder connecting seat 34. The pressure spring 33 is vertically installed and limited between the cylinder support 31 and the cylinder connecting seat 34.

[0038] See Figure 2 The hydraulic system includes a solenoid valve 41, a hydraulic multi-way valve 42, a controller 43, an oil pump motor 44, and a hydraulic oil pump 45;

[0039] The drive motor 25 is installed at the upper end of the vertical part of the L-shaped drive axle 21, and the drive wheel assembly 24 is installed on the outside of the vertical part of the L-shaped drive axle 21, so that the drive wheel assembly 24 is connected to the output shaft of the drive motor 25. The auxiliary wheel assembly 23 is installed at the horizontal extension end of the L-shaped drive axle 21 through the hydraulic cylinder connecting seat 34.

[0040] See Figure 3The hydraulic cylinder connecting seat 34 and the hydraulic cylinder support 31 have the same structure, including a horizontal connecting plate 341, a pair of hydraulic cylinder connecting lugs 342 and a step column 343. The step column 343 stands upright in the middle of the upper end of the connecting plate 341. The pair of hydraulic cylinder connecting lugs 342 are symmetrically arranged on the connecting plates 341 at both ends of the step column 343. The connecting plate 341 of the hydraulic cylinder connecting seat 34 is arranged horizontally and connected to the auxiliary wheel assembly 23. The connecting plate of the hydraulic cylinder support 31 is rotated 180° to be arranged horizontally and is fixedly connected to the frame 1, so that the pair of hydraulic cylinders 32 are installed vertically through the hydraulic cylinder connecting lugs, and the pressure spring 33 is installed vertically and limitedly through the step column 343.

[0041] See Figure 6 Each of the hydraulic cylinders has a piston rod lug 323 at the upper end of the piston rod and a cylinder lug 324 at the lower end of the cylinder barrel. The piston rod lug 323 and the cylinder lug 324 are respectively connected to the cylinder connecting support pin.

[0042] See Figure 7 The hydraulic system also includes a lifting cylinder control system and a balance valve 46. The lifting cylinder control system is used to realize the lifting function of the forklift lifting cylinder. The balance valve 46 balances the pressure of a pair of cylinders 32. The solenoid valve 41 is a full proportional solenoid valve.

[0043] The operation of the oil pump motor 44 causes the hydraulic oil pump 45 to generate oil pressure. The hydraulic oil from the hydraulic oil pump 45 is delivered to a pair of oil cylinders 32 via the hydraulic multi-way valve 42. A pair of pressure testing valves 322 on the pair of oil cylinders 32 monitor the oil pressure and transmit the signal to the controller 43 via the solenoid valve 41. The controller 43 controls the speed of the oil pump motor 44, and then controls the pressure of the pair of oil cylinders 32 by controlling the hydraulic multi-way valve 42. This causes the oil cylinder adjustment mechanism to exert a force on the auxiliary wheel assembly 23, so that the auxiliary wheel assembly 23 and the drive wheel assembly 24 rotate around the drive axle shaft 22 until the rated pressure is set by the control system. This forms a working cycle and feedback loop.

[0044] Specific working principle:

[0045] The driver operates the vehicle via the integrated control handle 13. When driving on a normal, flat road, the pair of load-bearing wheel assemblies 12, drive wheel assembly 24, and auxiliary wheel assembly 23 remain balanced. Because the force distributed across the wheel system by the vehicle's weight is balanced, the drive system essentially does not float around the axle. Since the load-bearing capacity of the auxiliary wheel assembly 23 does not change due to its own weight, the load-bearing capacity of the auxiliary wheel assembly 23 is the designed rated value. The hydraulic cylinder is in the set neutral position, and its working pressure is also the designed rated pressure. The pressure measured by the pressure test connector 321 remains constant, equivalent to the multi-way valve output pressure remaining constant. The pressure spring 33 bears a certain preload according to the set pressure. At this time, the hydraulic cylinder remains essentially horizontal and vertical.

[0046] When driving on uneven roads, the load-bearing wheel assembly 12, drive wheel assembly 24, and auxiliary wheel assembly 23 can no longer maintain balance. At this time, because the forces distributed on each wheel system by the vehicle's weight are unbalanced, the drive system will float around the axle. The load-bearing capacity of the auxiliary wheel assembly 23 changes; the load-bearing capacity of the auxiliary wheel assembly 23 may be greater than the designed rated value or less than the designed rated value.

[0047] When the force on the auxiliary wheel is less than the rated state:

[0048] At this point, the auxiliary wheel assembly 23 may be on a sunken surface, suspended in mid-air, or its load may be significantly reduced. In this case, the pressure measured by the pressure tester 321 will be lower than the system's set rated pressure. The pressure tester 321 transmits a signal indicating a pressure lower than the system's set pressure to the solenoid valve 41 via a wiring harness. The solenoid valve 41 then transmits the signal to the controller 43. The controller 43 then controls the oil pump motor 44 and the hydraulic oil pump 45 through a program to increase their speed and adjust the pressure of the hydraulic multi-way valve 42 to the system's set rated pressure. During this process, high-pressure oil enters the cylinder, causing the piston rod to move downwards. At this time, the auxiliary wheel assembly 23 and the drive wheel assembly 24 rotate clockwise around the drive axle shaft 22 until the pressure measured by the pressure tester 321 reaches the system's set rated pressure and stops moving. This process forms a cycle of automatic measurement, automatic feedback, and automatic adjustment.

[0049] When the force on the auxiliary wheel exceeds the rated state:

[0050] When the auxiliary wheel assembly 23 is overloaded or unevenly loaded, it indicates that the force on the drive wheel assembly 24 is reduced, causing the entire vehicle's drive wheel assembly 24 to slip and descend. At this time, the pressure measured by the pressure test connector 321 will be higher than the system's set rated pressure. The pressure test connector 321 transmits a signal exceeding the system's set pressure to the solenoid valve 41 via a wiring harness. The solenoid valve 41 then transmits the signal to the controller 43. The controller 43 then controls the oil pump motor 44 and the hydraulic oil pump 45 through a program to reduce their speed, adjusting the pressure of the hydraulic multi-way valve 42 to the system's set rated pressure. During this process, the cylinder unloads the high-pressure oil, causing the piston rod to move upwards. The auxiliary wheel assembly 23 and the drive wheel assembly 24 then rotate counterclockwise around the drive axle shaft 22 until the pressure measured by the pressure test connector 321 reaches the system's set rated pressure and stops moving. This process forms a cycle of automatic measurement, automatic feedback, and automatic adjustment.

[0051] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic control system for a stand-on reach truck, characterized in that: Includes the frame (1), drive mechanism and control system; A pair of load-bearing wheel assemblies (12) are mounted on a pair of front legs (11) of the frame (1). The drive mechanism includes an L-shaped drive axle (21), a drive axle shaft (22), an auxiliary wheel assembly (23), and a drive wheel assembly (24), the drive wheel assembly (24) being connected to the output shaft of the drive motor (25); The L-shaped drive axle (21) is arranged at the bottom of the rear of the frame (1), and the horizontal part of the L-shaped drive axle (21) is parallel to the lateral arrangement direction of the frame (1). The drive axle shaft (22) passes through the horizontal part of the L-shaped drive axle (21) longitudinally through the bearing seat and is mounted on the frame (1) through a pair of shaft fixing seats (26). The drive wheel assembly (24) is mounted on the outside of the vertical part of the L-shaped drive axle (21), and the auxiliary wheel assembly (23) is mounted on the horizontal part of the L-shaped drive axle (21) on both sides of the drive axle shaft (22), so that the auxiliary wheel assembly (23) and the drive wheel assembly (24) are located on the lateral sides of the rear of the frame (1). The control system includes a hydraulic system and a cylinder adjustment mechanism. The hydraulic cylinder adjustment mechanism includes a hydraulic cylinder support (31), a pair of hydraulic cylinders (32), a pressure spring (33), and a hydraulic cylinder connecting seat (34). Each hydraulic cylinder is equipped with a pressure testing valve (322) via a pressure testing connector (321). The cylinder connecting seat (34) and the auxiliary wheel assembly (23) are installed and connected. The cylinder support (31) is fixedly installed on the corresponding frame (1) above the cylinder connecting seat (34). A pair of cylinders (32) are vertically installed between the cylinder support (31) and the cylinder connecting seat (34). The pressure spring (33) is vertically installed and limited between the cylinder support (31) and the cylinder connecting seat (34). The hydraulic system includes a solenoid valve (41), a hydraulic multi-way valve (42), a controller (43), an oil pump motor (44), and a hydraulic oil pump (45). The operation of the oil pump motor (44) causes the hydraulic oil pump (45) to generate oil pressure. The hydraulic oil of the hydraulic oil pump (45) is delivered to a pair of oil cylinders (32) through the hydraulic multi-way valve (42). A pair of pressure measuring valves (322) on the pair of oil cylinders (32) monitor the oil pressure and transmit the signal to the controller (43) through the solenoid valve (41). The controller (43) adjusts the speed of the oil pump motor (44) and then adjusts the pressure of the pair of oil cylinders (32) by adjusting the hydraulic multi-way valve (42). This causes the oil cylinder adjustment mechanism to exert force on the auxiliary wheel assembly (23), so that the auxiliary wheel assembly (23) and the drive wheel assembly (24) rotate around the drive axle shaft (22) to the rated pressure set by the control system.

2. The automatic control system for a stand-on reach truck body according to claim 1, characterized in that: The hydraulic system also includes a lifting cylinder control system and a balance valve (46). The lifting cylinder control system is used to realize the lifting function of the forklift lifting cylinder. The balance valve (46) balances the pressure of a pair of cylinders (32). The solenoid valve (41) is a full proportional solenoid valve.

3. The automatic control system for a stand-on reach truck body according to claim 1, characterized in that: The drive motor (25) is installed at the upper end of the vertical part of the L-shaped drive axle (21), so that the drive wheel assembly (24) is connected to the output shaft of the drive motor (25), and the auxiliary wheel assembly (23) is installed at the horizontal extension end of the L-shaped drive axle (21) through the oil cylinder connecting seat (34).

4. The automatic control system for a stand-on reach truck body according to claim 1, characterized in that: The hydraulic cylinder connecting seat (34) and the hydraulic cylinder support (31) have the same structure, including a horizontal connecting plate (341), a pair of hydraulic cylinder connecting lugs (342) and a step column (343). The step column (343) is upright in the middle of the upper end of the connecting plate (341). A pair of hydraulic cylinder connecting lugs (342) are symmetrically arranged on the connecting plates (341) at both ends of the step column (343). The connecting plate (341) of the hydraulic cylinder connecting seat (34) is arranged horizontally and connected to the auxiliary wheel assembly (23). The connecting plate (341) of the hydraulic cylinder support (31) is rotated 180° to be arranged horizontally and is fixedly connected to the frame (1) accordingly, so that a pair of hydraulic cylinders (32) are installed vertically through the hydraulic cylinder connecting lugs, and the pressure spring (33) is installed vertically and limited through the step column (343).

5. The automatic control system for a stand-on reach truck body according to claim 4, characterized in that: Each of the cylinders has a piston rod lug (323) at the upper end of the piston rod and a cylinder lug (324) at the lower end of the cylinder barrel. The piston rod lug (323) and the cylinder lug (324) are respectively connected to the cylinder connecting support pin.

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