Hydraulic wrench pump system with one-key learning function and control method

Abstract

The invention relates to a hydraulic wrench pump system with a one-key learning function and a control method, the wrench pump system can realize a parameter learning function through one-key operation, and after parameter learning is completed, a bolt can be automatically pre-tightened in place. The method comprises the following steps that S1, a piston shrinks and stretches out under the no-load condition, and system pressure and time are obtained; s2, calibrating the relationship between the piston stroke change, the system pressure and the time; s3, the characteristic pressure of piston contraction and extension and the whole-course contraction time are determined; s4, automatic work is carried out, and the actual minimum pressure and the system real-time pressure when the piston stretches out are obtained; s5, when the real-time pressure of the system meets the condition, the piston shrinks, and the actual whole-course shrinkage time is recorded; and S6, when the actual whole-course contraction time meets the condition, the bolt is pre-tightened in place, and the pre-tightening action is repeated for multiple times. Compared with the prior art, the invention has the advantages of reducing overflow heating and system temperature rise, improving the working requirement, prolonging the service life and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic tool automation, and in particular to a hydraulic wrench pump system with a one-key learning function and a control method thereof. Background Art

[0002] Hydraulic wrenches are widely used in the installation and maintenance of wind power, nuclear power, petroleum, marine engineering and many other fields. When splicing large structures, a large number of bolts are often used as fasteners. The pre-tightening of these bolts cannot be achieved manually, so tools such as hydraulic wrenches, electric wrenches, and bolt tensioners are required.

[0003] Hydraulic wrenches are widely used due to their compact structure, high output torque, and ease of operation. A wide variety of hydraulic wrenches are available on the market, both domestically and internationally. They primarily come in two structural styles: hollow and square. Hollow hydraulic wrenches can be directly fitted onto nuts, making them more compact and suitable for applications where bolt spacing is relatively close. Square-drive hydraulic wrenches have a drive output shaft that drives the sleeve, allowing for more flexible replacement.

[0004] Both types of hydraulic wrenches are powered by a high-pressure pump station, with the wrench's rotation controlled by a switch on the operating handle. Due to the limitations of portability and high pressure, the pump station is lightweight and compact, and the high-pressure pump's output flow is also very low. Consequently, the hydraulic wrench rotates slowly, and tightening bolts requires repeated operation. A short-stroke piston within the wrench delivers torque via a ratchet. When the piston bottoms out, the system pressure rises to the maximum pressure set by the pump station. This pressure energy is converted into heat, causing the oil temperature to rise. Simultaneously, the pressure from the piston acts on the cylinder, causing some extrusion deformation and raising the temperature of the hydraulic wrench. Therefore, hydraulic wrenches often face the risk of excessively high temperatures during actual use, shortening their service life and wasting significant energy. Excessive temperature rises also require shutdown and cooling, reducing work efficiency.

[0005] Analysis of actual operating conditions revealed that the rise in wrench and oil temperatures is primarily due to prolonged high-pressure overflow and deformation of the piston and cylinder barrel. The root cause is excessive system pressure. Consequently, numerous studies have explored methods such as adding displacement sensors and control devices to prevent continued pressure after the piston bottoms out, or using torque sensors to detect output torque.

[0006] For example, the invention with publication number CN102581804A discloses a high-precision intelligent hydraulic torque wrench special pump and a hydraulic torque wrench control method. By setting an electromagnetic reversing valve and a pressure sensor in the hydraulic pump and the oil cylinder, and using a processor to monitor and compare the pressure threshold and time, high-precision automatic control of the hydraulic wrench is achieved; the invention with publication number CN104972423A discloses a bolt tightening detection method, device, system and hydraulic wrench. By using a pressure recorder in the hydraulic wrench to obtain pressure data during the bolt tightening process, the problems of low detection accuracy of the hydraulic wrench and the need for supervision by quality inspectors are solved.

[0007] However, the control method of the aforementioned wrench pump is often not accepted by frontline operators during actual field use due to the complexity of the equipment, the need for a large number of parameter settings during operation, and a high failure rate. Furthermore, with each stroke of its automated operation, the system approaches the maximum system pressure, causing the system to be under high operating pressure for each bolt tightening. This causes the system to heat up too quickly and become too hot, thereby shortening the service life of the wrench and causing a large amount of energy waste. Therefore, there is an urgent need to propose an intelligent hydraulic wrench control system and method that operates in a suitable pressure environment and can achieve automatic intelligent operation through one-click learning. Summary of the Invention

[0008] The purpose of the present invention is to overcome the defect of the above-mentioned prior art that the system pressure formed by each tightening of the wrench is close to the maximum pressure, causing the system temperature to rise too quickly, the temperature to be too high, and shortening the service life of the wrench. The present invention provides a hydraulic wrench pump system that can learn the control parameters of the corresponding wrench through a simple one-button operation, automatically complete the subsequent tightening operation, and realize the intelligentization of the equipment, which is used to reduce the heat generation of the wrench and the pump station, improve work efficiency, and reduce labor intensity.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] This solution provides an automatic control method for a hydraulic wrench pump, comprising the following steps:

[0011] S1: Under no-load conditions, the wrench piston is retracted and extended, and the piston action time is recorded to collect the real-time changes in system pressure and mark the moment when the system pressure suddenly changes;

[0012] S2: Based on the acquired system pressure change and the recorded marked time, the calibration relationship between the wrench piston stroke change, system pressure and time is completed;

[0013] S3: The maximum pressure P_B_max and the minimum pressure P_B_min of the piston retraction, the minimum pressure P_F_min and the maximum pressure P_F_max of the piston no-load extension, and the no-load full retraction time of the piston are collected;

[0014] S4: Under automatic working conditions, the piston of the wrench is extended to obtain the actual minimum pressure and real-time pressure of the system during the piston extension process;

[0015] S5: When the system real-time pressure is greater than the average of the system's actual minimum pressure and the maximum extended pressure P_F_max, the wrench's piston retracts, and the actual full-stroke retraction time of the piston is recorded;

[0016] S6: When the double value of the actual full-stroke retraction time of the piston is less than the no-load full-stroke retraction time, the bolt is pre-tightened in place and S7 is executed; otherwise, the process returns to S4;

[0017] S7: After the bolt is pre-tightened, the hydraulic wrench repeats the pre-tightening action for more than 2 times to complete the automatic pre-tightening operation and wait for the next bolt pre-tightening work.

[0018] Furthermore, the specific operation process of collecting the piston pressure and the no-load full return time in S3 includes the following steps:

[0019] S201: Under no-load conditions, start the hydraulic wrench pump and perform initialization operations;

[0020] S202: Start the pump station system to increase pressure, adjust the electromagnetic reversing valve, and retract the piston in the wrench to the bottom. The system pressure at this time is recorded as the maximum pressure P_B_max of the piston retraction;

[0021] S203: Adjust the electromagnetic reversing valve to extend the piston in the wrench, and record the time t_F0 at this moment. Record the minimum system pressure during the piston extension process, which is the minimum pressure for piston extension P_F_min, and record the time t_F1 when the system pressure starts to rise;

[0022] S204: When the piston is fully extended, the system pressure rises. The system pressure after stabilization is recorded as the maximum extension pressure P_F_max, and the time t_F2 when the system pressure reaches the maximum is recorded.

[0023] S205: Regulate the electromagnetic reversing valve to retract the wrench piston, and record the time at this moment. The minimum pressure of the system during the piston retraction process is recorded as the minimum pressure of the piston retraction P_B_min, and the time when the system pressure starts to rise t_B1 is recorded.

[0024] S206: When the system pressure reaches the maximum pressure P_B_max for piston contraction, the time t_B2 at this moment is recorded, and the no-load full contraction time of the piston t_Back = / 2-t_B0.

[0025] Furthermore, in S7, when the process pre-tightening bolt reaches the maximum working pressure, the hydraulic wrench performs at least but not limited to three tightening actions at the maximum process pressure, and each tightening action is maintained for a preset time.

[0026] This solution also provides a hydraulic wrench pump system with a one-key learning function, which operates according to the above-mentioned automatic control method of the hydraulic wrench pump. The system includes a hydraulic unit and a control unit connected to each other, and the hydraulic unit includes an electromagnetic reversing valve, a wrench pump high-pressure relief valve, a hydraulic pump drive motor, a high-pressure pump and a pressure sensor;

[0027] The hydraulic pump drive motor is connected to the high-pressure pump, the input end of the high-pressure pump is connected to the pump station oil tank, and the output end is connected to the hydraulic wrench through an electromagnetic reversing valve. The pressure sensor is installed at the output end of the high-pressure pump to monitor the system pressure. The wrench pump high-pressure relief valve is connected to the output end of the high-pressure pump to set the maximum pressure of the system according to the pre-tightening force of the bolt.

[0028] Preferably, the hydraulic unit further comprises a wrench pump low-pressure relief valve, a low-pressure pump and a one-way valve;

[0029] The inlet side of the one-way valve is connected to the output end of the low-pressure pump, and the outlet side is connected to the output end of the high-pressure pump. The wrench pump low-pressure relief valve is connected to the output end of the low-pressure pump, and is used to limit the opening pressure of the one-way valve, and open the one-way valve when the wrench piston is unloaded.

[0030] Preferably, the hydraulic unit also includes a return oil pressure setting relief valve, which is used to set the maximum pressure of the return contraction of the piston in the hydraulic wrench. The pressure value set by the return oil pressure setting relief valve is higher than the setting value of the wrench pump low-pressure relief valve and lower than the setting value of the wrench pump high-pressure relief valve.

[0031] Preferably, the control unit includes a wrench pump controller and a wrench pump operating handle connected to each other, the wrench pump controller is electrically connected to the electromagnetic reversing valve, the pressure sensor and the hydraulic pump drive motor respectively, and the wrench pump operating handle is used to manually control and obtain the operating status of the wrench pump.

[0032] Preferably, the wrench pump controller includes a housing, a connector and a PCB circuit board. The PCB circuit board is installed in the housing, and the connector is installed on the housing for connecting the system wiring harness with the PCB circuit board. The PCB circuit board is used for data transmission and communication, and for detecting and storing data.

[0033] Preferably, the wrench pump operating handle includes a handle body and button 1, button 2, button 3 and an indicator light arranged on the handle body;

[0034] The button No. 1 is used to control the start and stop of the pump, the button No. 2 is used to adjust the circumferential action of the electromagnetic reversing valve and one-button learning, the button No. 3 is used to control the start and stop of the automatic operation of the hydraulic wrench pump, and the indicator light uses a variety of flashing frequencies to display the status of one-button learning and the operating status of the pump station.

[0035] Preferably, the solenoid reversing valve is a two-position four-way solenoid reversing valve, or it can be a three-position four-way solenoid reversing valve with an M-type center position or a combination of two two-position three-way solenoid reversing valves, which is used to control the switching of the forward and return strokes of the wrench. The stable working pressure of the solenoid reversing valve is higher than 60MPa, and the switching frequency is greater than 10Hz.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. This solution collects the calibration relationship between the system's pressure change, time, and piston stroke change under no-load conditions of the wrench pump system. The control module can then control the maximum pressure of the wrench's single stroke based on the system's real-time pressure and the set threshold. As the number of wrench tightenings increases, the maximum pressure is gradually increased to complete the tightening of the bolt. The piston's return time is used to determine whether the bolt is tightened. Compared to tightening multiple times with a specific pressure, incremental pressure tightening can effectively reduce system heat generation, the rate of temperature rise, and the system temperature, extending the service life of the wrench. The wrench is also simple to calibrate; it only needs to be run no-load once for the control module to complete automatic learning, realizing one-click learning and automated control of the system, reducing the system's operating difficulty, improving the system's work efficiency, and reducing labor intensity.

[0038] 2. In this solution, the high-pressure pump and the low-pressure pump cooperate to control the movement of the wrench's piston. When the load pressure is lower than the set pressure of the low-pressure pump relief valve, the oil can push open the one-way valve and enter the main oil system. At this time, the hydraulic wrench has a light load and is in an idling state or the bolt has no torque load. The low-pressure, high-flow pump and the high-pressure, low-flow pump simultaneously supply oil to the system to achieve fast forward, shortening the working time of the hydraulic wrench and improving work efficiency. In addition, the reduction in system pressure can also effectively control the heating of the system.

[0039] 3. This solution uses the one-button learning function of the operating handle to obtain control parameter information for different types of hydraulic wrenches and bolts during the tightening process, thereby realizing automatic pre-tightening control of the wrench pump. Compared with conventional wrench pump controllers, this solution does not require additional sensor equipment, parameter settings, or model selection, thus simplifying the workload and operating difficulty of front-line operators and providing good human-computer interaction.

[0040] 4. This solution allows automatic operation after one-click learning. Manual and automatic re-pressurization can be switched midway. Once the bolts are tightened, the system automatically stops, shuts down the pump station motor, and enters standby mode. During the automatic repressurization process, the control system automatically adjusts the reversing time based on the relationship between the system pressure signal and time. This prevents idle stroke repressurization, reduces overflow heat, slows down the temperature rise of the pump station and wrench, improves work efficiency, and extends the operating time of the hydraulic wrench and pump station. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the composition of the intelligent wrench pump system in an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of the operating handle of the intelligent wrench pump in an embodiment of the present invention;

[0043] Figure 3 Schematic diagram of the working principle of the hydraulic system in an embodiment of the present invention;

[0044] Figure 4 This is a timing diagram of the one-key learning function in an embodiment of the present invention;

[0045] Figure 5 This is a logic block diagram of the working process control of the intelligent wrench pump in an embodiment of the present invention;

[0046] Figure 6 This is a flowchart for implementing the one-key learning function in an embodiment of the present invention;

[0047] Figure 7 is a three-dimensional schematic diagram of a wrench pump controller in an embodiment of the present invention;

[0048] Figure 8 1 is an interface diagram of a wrench pump controller in an embodiment of the present invention;

[0049] Figure 9 The pin definitions of the wrench pump controller in the embodiment of the present invention;

[0050] Figure 10 This is a functional diagram of the MCU interface in the controller in an embodiment of the present invention;

[0051] In the figure: 101, electrical junction box; 102, wrench pump controller; 103, operating handle; 104, AC motor; 105, hydraulic circuit valve block; 106, hydraulic wrench connecting oil pipe quick connector; 107, pump station oil tank; 1031, button 2; 1032, finger groove; 1033, anti-slip rubber shell; 1034, connecting cable; 1035, indicator light; 1036, button 1; 1037, button 3; 201, hydraulic wrench; 202, return oil pipe; 203, return oil pressure setting relief valve; 204, solenoid reversing valve; 205, wrench pump high-pressure relief valve; 206, hydraulic pump drive motor; 207, high-pressure pump; 208, oil inlet pipe; 209, pressure gauge; 210, pressure sensor; 211, wrench pump low-pressure relief valve; 212, low-pressure pump; 213, oil tank. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0053] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0054] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0055] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0056] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0057] Example 1

[0058] like Figure 4-6 As shown, this embodiment provides an automatic control method for a hydraulic wrench pump, comprising the following steps:

[0059] S1: Under no-load conditions, the wrench piston is retracted and extended, and the piston action time is recorded to collect the real-time changes in system pressure and mark the moment when the system pressure suddenly changes;

[0060] S2: Based on the acquired system pressure change and the recorded marked time, the calibration relationship between the wrench piston stroke change, system pressure and time is completed;

[0061] S3: The maximum pressure P_B_max and the minimum pressure P_B_min of the piston retraction, the minimum pressure P_F_min and the maximum pressure P_F_max of the piston no-load extension, and the no-load full retraction time of the piston are collected;

[0062] S4: Under automatic working conditions, the piston of the wrench is extended to obtain the actual minimum pressure and real-time pressure of the system during the piston extension process;

[0063] S5: When the system real-time pressure is greater than the average of the system's actual minimum pressure and the maximum extended pressure P_F_max, the wrench's piston retracts, and the actual full-stroke retraction time of the piston is recorded;

[0064] S6: When the double value of the actual full-stroke retraction time of the piston is less than the no-load full-stroke retraction time, the bolt is pre-tightened in place and S7 is executed; otherwise, the process returns to S4;

[0065] S7: After the bolt is pre-tightened, the hydraulic wrench repeats the pre-tightening action for more than 2 times to complete the automatic pre-tightening operation and wait for the next bolt pre-tightening work.

[0066] In this embodiment, the specific operation process of collecting the piston pressure and the no-load full return time in S3 includes the following steps:

[0067] S201: Under no-load conditions, start the hydraulic wrench pump and perform initialization operations;

[0068] S202: Start the pump station system to increase pressure, adjust the electromagnetic reversing valve, and retract the piston in the wrench to the bottom. The system pressure at this time is recorded as the maximum pressure P_B_max of the piston retraction;

[0069] S203: Adjust the electromagnetic reversing valve to extend the piston in the wrench, and record the time t_F0 at this moment. Record the minimum system pressure during the piston extension process, which is the minimum pressure for piston extension P_F_min, and record the time t_F1 when the system pressure starts to rise;

[0070] S204: When the piston is fully extended, the system pressure rises. The system pressure after stabilization is recorded as the maximum extension pressure P_F_max, and the time t_F2 when the system pressure reaches the maximum is recorded.

[0071] S205: Regulate the electromagnetic reversing valve to retract the wrench piston, and record the time at this moment. The minimum pressure of the system during the piston retraction process is recorded as the minimum pressure of the piston retraction P_B_min, and the time when the system pressure starts to rise t_B1 is recorded.

[0072] S206: When the system pressure reaches the maximum pressure P_B_max of the piston contraction, the time t_B2 at this moment is recorded, and the no-load full contraction time of the piston t_Back = (t_B2-t_B1) / 2-t_B0.

[0073] In a preferred embodiment, in S7, after the process pre-tightening bolt reaches the maximum working pressure, the hydraulic wrench performs at least but not limited to three tightening actions at the maximum process pressure, and each tightening action is maintained for a preset time.

[0074] In combination with the above preferred implementation methods, this embodiment provides a more specific automatic control method for a hydraulic wrench pump, such as Figure 4-6 The following steps are involved:

[0075] S1, the pump station and wrench hydraulic pipelines are correctly connected, the pump station is powered on, the system manual relief valve is adjusted to the pressure corresponding to the bolt pre-tightening, the operating handle is in place, the system is started, the pump station completes initialization, and the indicator light flashes slowly;

[0076] S2: Start the pump station system to increase pressure. At this time, the electromagnetic reversing valve 204 is in the right position, and the piston in the wrench is retracted to the bottom. The system pressure at this time is the maximum pressure of reverse retraction P_B_max. After the pressure stabilizes, this pressure is automatically stored in the ECU;

[0077] S3, press button 2, the ECU records the pressing time t_F0, the electromagnetic reversing valve 204 is energized, the left position works, the wrench piston extends, and because the wrench is idling at this time, the system pressure decreases. At this time, the system pressure is the no-load extension pressure P_F_min, and the minimum value is stored in the ECU. At the same time, when the system pressure starts to rise, the time t_F1 is automatically recorded;

[0078] S4: The wrench piston extends to the bottom and the system starts to pressurize. When the system reaches the maximum pressure, the ECU records the time t_F2.

[0079] S5, after the system pressure stabilizes, the maximum pressure P_F_max is stored. This pressure is the maximum pressure at which the corresponding wrench is pre-tightened into place;

[0080] S6, release button 2, the ECU records the pressing time t_B0, the electromagnetic reversing valve 204 loses power, the right position works, the ratchet is pushed back, the nut does not move, the wrench piston retracts, and the minimum pressure P_B_min during the retraction process is automatically stored. When the system pressure starts to rise, the time t_B1 is automatically recorded;

[0081] S7, the wrench piston retracts to the bottom, the system begins to pressurize, and when the system reaches the maximum pressure, the ECU records the time t_B2. The full piston return time t_Back is stored as (t_B2-t_B1) / 2-t_B0. The intelligent wrench pump completes one-key learning, the indicator light stays on, and the hydraulic wrench can automatically pressurize and pre-tighten.

[0082] S8, the wrench piston retracts to the bottom, the system begins to pressurize, and when the system reaches the maximum pressure, the ECU records the time t_B2. The intelligent wrench pump completes one-click learning, the indicator light stays on, and the hydraulic wrench can automatically pressurize and pre-tighten;

[0083] S9, when the automatic operation button No. 3 is pressed, the system starts to work automatically, the electromagnetic reversing valve 204 is energized, works in the left position, and performs the i-th (i=1, 2, 3...i∈N) bolt pre-tightening. The wrench piston extends and the minimum pressure P_F_i_min during the piston extension process is recorded. When P_F_i_min<=1.2*P_F_min, the wrench stroke is idle rotation and the bolt is not stressed. When the system pressure is greater than (P_F_max+P_F_i_min) / 2, the electromagnetic reversing valve 204 is de-energized and the wrench piston retracts.

[0084] S10, the electromagnetic reversing valve 204 loses power, the wrench piston retracts, and the ECU timer starts timing. After the electromagnetic reversing valve loses power for t_Back, the electromagnetic reversing valve 204 is energized. At the same time, the return time t_Back_i when the piston returns to its original position when the system pressure is greater than P_B_min during this stroke is recorded.

[0085] The solenoid valve 204 is energized, the piston extends, and the i+1 stroke begins to be pressed. When P_F_(i+1)_min>1.2*P_F_min, the bolt begins to generate torque in this stroke, entering the bolt pre-tightening stage, and the bolt begins to be pre-tightened. When the system pressure exceeds (P_F_max+P_F_(i+1)_min) / 2, the solenoid valve 204 is de-energized, and the wrench piston retracts.

[0086] S11. Repeatedly execute the S8->S9 actions. When t_Back_i < t_Back / 2, it indicates that the piston return time is significantly less than the normal return time, and the wrench piston should not be fully extended. That is, in this stroke, the piston reaches the maximum preload force before fully extending to the bottom, indicating that the preloading is in place. After the preloading is in place, perform 3 more preloading actions continuously to release the stress between the structures. After the system automatically completes the pressure boosting, the electromagnetic directional valve loses power and the pump station stops, entering the standby mode and proceeding to the operation of the next bolt.

[0087] This control method acquires the calibration relationship between the pressure change of the wrench pump system under no-load conditions, the time, and the piston stroke change. Then, the control module can compare the real-time pressure of the system with the set threshold to control the maximum pressure of a single stroke of the wrench. And as the number of times the wrench tightens increases, the maximum pressure is gradually increased to complete the tightening of the bolt. It judges whether the bolt tightening is completed by the return time of the piston. Compared with tightening multiple times with a specific pressure and pressure increasing tightening, the pressure increasing tightening can effectively reduce the system heat generation, the temperature rising rate, and the system temperature, and extend the service life of the wrench. Moreover, the calibration of the wrench is simple. Only need to run it without load once, and the control module can complete the automatic learning, realizing the one-key learning automatic control of the system, reducing the operation difficulty of the system, improving the working efficiency of the system, and reducing the labor intensity.

[0088] Embodiment 2

[0089] As Figure 1-3 shown, this embodiment provides a hydraulic wrench pump system with a one-key learning function, which operates according to the automatic control method of the hydraulic wrench pump in Embodiment 1. The system includes a hydraulic unit and a control unit connected to each other. It is characterized in that the hydraulic unit includes an electromagnetic directional valve 204, a wrench pump high-pressure relief valve 205, a hydraulic pump drive motor 206, a high-pressure pump 207, and a pressure sensor 210;

[0090] The hydraulic pump drive motor 206 is drivingly connected to the high-pressure pump 207. The input end of the high-pressure pump 207 is connected to the fuel tank 213, and the output end is connected to the hydraulic wrench 201 through the electromagnetic directional valve 204. The pressure sensor 210 is installed at the output end of the high-pressure pump 207 to monitor the system pressure. The wrench pump high-pressure relief valve 205 is connected to the output end of the high-pressure pump 207 to set the maximum pressure of the system according to the preload force of the bolt.

[0091] Preferred implementation mode, the hydraulic unit further includes a wrench pump low-pressure relief valve 211, a low-pressure pump 212, and a check valve;

[0092] The inlet side of the one-way valve is connected to the output end of the low-pressure pump 212, and the outlet side is connected to the output end of the high-pressure pump 207. The wrench pump low-pressure relief valve 211 is connected to the output end of the low-pressure pump 212, which is used to limit the opening pressure of the one-way valve and open the one-way valve when the wrench piston is unloaded.

[0093] The high-pressure pump and the low-pressure pump cooperate to control the movement of the wrench's piston. When the load pressure is lower than the set pressure of the low-pressure pump relief valve, the oil can push open the one-way valve and enter the main oil system. At this time, the hydraulic wrench has a light load and is in an idling state or the bolt has no torque load. The low-pressure, high-flow pump and the high-pressure, low-flow pump simultaneously supply oil to the system to achieve fast forward, shortening the working time of the hydraulic wrench and improving work efficiency. In addition, the reduction in system pressure can also effectively control the heating of the system.

[0094] Furthermore, the hydraulic unit also includes a return oil pressure setting relief valve 203, which is used to set the maximum pressure of the return contraction of the piston in the hydraulic wrench. The pressure value set by the return oil pressure setting relief valve 203 is higher than the setting value of the wrench pump low-pressure relief valve 211 and lower than the setting value of the wrench pump high-pressure relief valve 205.

[0095] In this embodiment, Figure 7-10 As shown, the control unit includes a wrench pump controller 102 and a wrench pump operating handle 103 that are interconnected. The wrench pump controller 102 is electrically connected to the electromagnetic reversing valve 204, the pressure sensor 210 and the hydraulic pump drive motor 206 respectively. The wrench pump operating handle 103 is used to manually control and obtain the operating status of the wrench pump.

[0096] The wrench pump controller 102 includes a housing, a connector and a PCB circuit board. The PCB circuit board is installed in the housing and the connector is installed on the housing for connecting the system wiring harness with the PCB circuit board. The PCB circuit board is used for data transmission and communication, and for detecting and storing data.

[0097] In this embodiment, the operating handle 103 includes a handle body and a No. 1 button 1036, a No. 2 button 1031, a No. 3 button 1037 and an indicator light 1035 provided on the handle body;

[0098] Button 1036 controls the pump's start and stop. Button 2 1031 adjusts the solenoid directional control valve 204's switching action and enables one-touch learning. Button 3 1037 controls the hydraulic wrench pump's automatic start and stop. Indicator light 1035 displays the one-touch learning status and the pump station's operational status through various flashing frequencies (slow flashing indicates the control parameters haven't been learned; constant on indicates the correct pressure and time parameters have been learned). The handle itself is equipped with a finger groove 1032 and a non-slip rubber cover 1033 for easy operation. The handle is connected to the wrench pump controller 102 via a connecting cable 1034.

[0099] Specifically, the electromagnetic reversing valve 204 is a two-position four-way electromagnetic reversing valve, which is used to control the switching between the forward stroke and the return stroke of the wrench. The stable working pressure of the electromagnetic reversing valve 204 is higher than 60 MPa, and the switching frequency is greater than 10 Hz.

[0100] In combination with the above preferred embodiments, this embodiment also provides a more specific structure of a hydraulic wrench pump system with a one-key learning function, which is composed of an electrical junction box 101, a wrench pump controller 102, an operating handle 103, an AC motor 104, a hydraulic circuit valve block 105, a hydraulic wrench connecting oil pipe quick connector 106, and a pump station oil tank 107. The high-pressure pump hydraulic system is equipped with a motor control unit, a hydraulic pump unit, a hydraulic valve control unit, a hydraulic measurement unit, and hydraulic auxiliary components, which are used to provide a power source for the hydraulic wrench and control the operation of the hydraulic wrench; the wrench pump controller 102 includes a waterproof housing, connectors, and a PCB circuit board, which are used to detect and collect sensor information of the wrench pump, analyze and process it, and control the operation of the wrench pump; the operating handle is used by the operator to control the pump station and understand the operating status of the wrench pump; the hydraulic wrench has a cylinder piston, a ratchet, and a pawl structure inside, which are used to tighten and loosen nuts and bolts.

[0101] In this embodiment, the intelligent hydraulic wrench pump system with a one-button learning function can be used together with the high-pressure pump station as part of the overall system, or it can be independent of the wrench pump as a control system external to the wrench pump. It can be applicable to the pump station of the hollow hydraulic wrench, and it can also be applicable to the pump station of the square drive hydraulic wrench. The motor of the motor control unit of the high-pressure hydraulic system of the intelligent wrench pump can be an AC motor, a DC motor, a stepper motor, or a servo motor. The electrical junction box of the motor control unit of the high-pressure hydraulic system of the intelligent wrench pump is equipped with an AC contactor for controlling the start and stop of the motor, or a frequency converter for controlling the operation of the motor, or a driver for controlling the stepper motor, or a servo controller for controlling the servo motor, and can receive signals from an external controller to control the start and stop of the motor.

[0102] In this embodiment, the hydraulic pump unit can be a two-stage pump consisting of a low-pressure, high-flow pump and a high-pressure, low-flow pump connected in series. Alternatively, the low-pressure pump and high-pressure pump can be independently driven by two motors, or there can be only one high-pressure pump. The low-pressure pump and high-pressure pump can be designed as a single unit or as two separate components. Their purpose is to provide pressure energy for the entire hydraulic system. The hydraulic pump of the hydraulic pump unit can be a gear pump or a plunger pump for the low-pressure pump, and a plunger pump for the high-pressure pump, enabling no-load fast forward and high-pressure working forward for the hydraulic wrench.

[0103] Furthermore, the one-way valve of the hydraulic valve control unit is installed between the outlet of the low-pressure pump 212 and the main oil circuit. When the load pressure is lower than the set pressure of the low-pressure pump relief valve, the oil can push open the one-way valve and enter the main oil system. At this time, the load of the hydraulic wrench is light, the hydraulic wrench is in an idling state or the bolt has no torque load. The low-pressure high-flow pump and the high-pressure low-flow pump simultaneously supply oil to the system to achieve fast forward, shortening the working time of the hydraulic wrench and improving work efficiency; when the load pressure is higher than the set pressure of the low-pressure pump relief valve, the oil of the low-pressure pump 212 cannot push open the one-way valve, and the oil of the low-pressure pump overflows directly through the low-pressure pump relief valve. At this time, the high-pressure pump 207 supplies oil to the system, the hydraulic wrench 201 outputs a large torque, or the oil cylinder piston of the hydraulic wrench has reached the bottom, and it is necessary to reverse to perform the second working cycle of the hydraulic wrench 201.

[0104] In this embodiment, the wrench pump low-pressure relief valve 211 of the hydraulic valve control unit is installed between the outlet of the low-pressure pump 212 and the one-way valve. The purpose is to set the pressure at the outlet of the low-pressure pump 212. The set pressure should be able to meet the working pressure of the wrench when it is unloaded. If the pressure value is set too high, it will cause system heating and energy loss. If it is set too low, the no-load fast forward action requirement cannot be achieved. The pressure of the relief valve is fixed after setting and is no longer adjusted frequently, or a fixed-value relief valve is directly used, and no adjustment is made after factory installation. The set pressure is usually less than 8MPa.

[0105] In this embodiment, the wrench pump high-pressure relief valve 205 of the hydraulic valve control unit is installed at the outlet of the high-pressure pump 207 and is used to set the outlet pressure of the high-pressure pump 207. This pressure is the maximum working pressure of the system and is also the pressure corresponding to the bolt pre-tightening. The pressure changes according to the model of the bolt and the working conditions. The installation of the relief valve should be easy to adjust. The pressure can be adjusted by rotating the handwheel, or the pressure can be set by using a proportional relief valve. The performance of the high-pressure pump relief valve determines the accuracy of the bolt pre-tightening force. A high-pressure relief valve with stable pressure, small fluctuation and high repeatability should be used.

[0106] In this embodiment, the electromagnetic reversing valve 204 of the hydraulic valve control unit is used to control the switching of the forward and return strokes of the wrench. It can be a two-position four-way electromagnetic reversing valve, or a three-position four-way electromagnetic reversing valve with an M-type middle position, or a combination of two two-position three-way electromagnetic reversing valves to realize the reversing function. The valve is used to switch the oil supply to the two chambers of the piston cylinder in the hydraulic wrench to realize the reciprocating motion of the piston. The working pressure level of the reversing valve is relatively high, and the pressure at which it can work stably must be higher than 60MPa, and the switching frequency must be greater than 10Hz.

[0107] In this embodiment, the return oil pressure of the hydraulic valve control unit sets the overflow valve 203, which is used to set the maximum pressure after the cylinder piston in the hydraulic wrench 201 returns to the bottom. The set pressure is higher than the pressure value set by the low-pressure overflow valve 211 of the low-pressure wrench pump, and lower than the pressure set by the high-pressure overflow valve 205 of the wrench pump. The setting of this pressure value depends on the pressure value required for the wrench return when oil enters the rod chamber. The set pressure is usually between 10 and 15 MPa. The hydraulic wrench return pressure is set separately. Its purpose is to reduce the overflow heat after the cylinder returns to the bottom, and to avoid damage to the structure of the hydraulic wrench due to long-term high pressure.

[0108] In this embodiment, the hydraulic pressure measurement unit includes at least one pressure sensor 210 installed in the main system oil circuit. This pressure sensor 210, located between the outlet of the high-pressure pump 207 and the solenoid reversing valve 204, measures the pressure of the hydraulic wrench 201 during its forward stroke, cylinder extension stroke, retraction stroke, and full retraction. To facilitate on-site observation and debugging, a pointer pressure gauge or digital pressure gauge 209 is installed in the oil circuit of the pressure sensor 210. The solenoid reversing valve 204 is connected to the hydraulic wrench 201 via a return oil pipe 202 and an inlet oil pipe 208.

[0109] In this embodiment, the hydraulic auxiliary parts include oil pipes, quick connectors, oil filters, and radiators to ensure the normal operation of the hydraulic system. The oil block is installed on the oil cylinder cover of the pump station. The oil block is used to install hydraulic valves, pressure sensors, and connectors. Its internal pipes are connected to the hydraulic principle. Figure 1 The material can be aluminum alloy, stainless steel or 45 steel.

[0110] In this embodiment, the housing of the intelligent wrench pump controller is used to place the PCB circuit board, and the connector is used to connect the wiring harness to the PCB circuit board. After the installation and wiring are completed, the IP level is greater than IP56 and can be used outdoors without protection.

[0111] Preferably, the PCB circuit board of the intelligent wrench pump controller has at least a programmable microprocessor chip, a power step-down module, an analog amplification and filtering circuit, a P-MOSFET driven power output port, and a digital input port; it may also have a serial communication port, an IIC bus port, a CAN bus port, and a Bluetooth port for data transmission and communication, and detection and storage of work process data.

[0112] Preferably, the operating handle of the intelligent wrench pump controller has at least three buttons and an indicator light. Button 1 is used to control the start and stop of the pump, button 2 is used for the reversing operation of the wrench pump electromagnetic reversing valve and the first-key learning, and button 3 is used to turn automatic operation on and off. The indicator light displays the status of the one-key learning and the operating status of the pump station by flashing at different frequencies. The functions of the above buttons and indicator lights can also be integrated into the touch screen, but the functions realized and the information to be displayed are the same.

[0113] In this embodiment, the hydraulic wrench of the intelligent wrench pump can be any hydraulic wrench available on the market, but the internal structure of the hydraulic wrench needs to include a ratchet and a pawl, and the piston rod pushes the pawl to drive the ratchet to rotate.

[0114] In this embodiment, the one-touch learning function relies solely on a single pressure sensor to measure and learn the hydraulic wrench's operating parameters with a single button press. This one-touch learning method divides the wrench's automatic pretightening process into four stages based on the learned parameters: the first operation teaching parameter learning stage, the idle stroke tightening stage, the bolt force stage, and the bolt pretightening stage. The current bolt pretightening stage is determined based on system pressure and cylinder return time, resulting in different control signals being issued by the controller.

[0115] The specific process of implementing the one-key learning function includes: before working, adjust the maximum working pressure of the wrench pump according to the pre-tightening force required by the corresponding bolt. During the continuous operation of multiple bolts, the maximum working pressure does not need to be adjusted again for bolts with the same pre-tightening force, but the maximum working pressure of the system needs to be reset for bolts with different pre-tightening forces.

[0116] The time parameters and pressure parameters of the hydraulic wrench action are learned through the no-load dry tightening of the hydraulic wrench, and these parameter information is saved in the controller. When these parameter information are obtained, the logical relationship between the time and pressure of each action is automatically determined. When all aspects of verification are passed, the parameter learning is automatically determined to be successful. The change in the flashing frequency of the indicator light shows that the parameter information has been obtained, and the tightening operation of the wrench can be automatically performed.

[0117] The button action on the operating handle that controls the reversing of the electromagnetic reversing valve is used as a trigger signal. On the one hand, it controls the action of the electromagnetic reversing valve, and on the other hand, it starts updating the parameters, recording the system pressure when the button is pressed, the time when the button is pressed, the minimum pressure during the extension process of the cylinder, the time when the pressure starts to rise during the extension process, the maximum pressure during the piston process, the time when the pressure rises to the maximum value and remains unchanged, the time when the button is released, the minimum pressure during the return stroke of the piston, the time when the pressure starts to rise during the return stroke, the maximum pressure during the return stroke, and the time when the maximum pressure during the return stroke is reached.

[0118] The collected parameters are used to optimize the time during the automatic reversing process to avoid high-pressure overflow in the system caused by the cylinder bottoming out during the forward and return strokes when the wrench is tightening the bolts, thereby reducing system heat and power consumption. The time it takes for the system to start boosting pressure after each reversal is used to determine whether the cylinder piston has bottomed out. If the time it takes to start boosting pressure is less than the time it takes to dry tighten, it is determined that the bolt has begun to have preload force. When the cylinder piston's return stroke time begins to shorten, it is determined that the wrench is not dry in this working stroke. In the next process, the reversing control pressure is increased, and the cycle repeats until the process pressure reaches the maximum working pressure learned during the dry tightening process.

[0119] During the automatic tightening process, after the process pre-tightening bolt reaches the maximum working pressure, it is tightened at least but not limited to 3 times at the maximum process pressure. Each tightening is maintained for a certain time to eliminate the friction and stress between the bolts, nuts, gaskets and structures to achieve the best prestressing effect.

[0120] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for automatically controlling a hydraulic wrench pump, characterized in that: The following steps are involved: S1: Under no-load conditions, the wrench piston is retracted and extended, and the piston action time is recorded to collect the real-time changes in system pressure and mark the moment when the system pressure suddenly changes; S2: Based on the acquired system pressure change and the recorded marked time, the calibration relationship between the wrench piston stroke change, system pressure and time is completed; S3: The maximum pressure P_B_max and the minimum pressure P_B_min of the piston retraction, the minimum pressure P_F_min and the maximum pressure P_F_max of the piston no-load extension, and the no-load full retraction time of the piston are collected; S4: Under automatic working conditions, the piston of the wrench is extended to obtain the actual minimum pressure and real-time pressure of the system during the piston extension process; S5: When the system real-time pressure is greater than the average of the system's actual minimum pressure and the maximum extended pressure P_F_max, the wrench piston retracts, and the actual full-stroke retraction time of the piston is recorded; S6: When the double value of the actual full-stroke retraction time of the piston is less than the no-load full-stroke retraction time, the bolt is pre-tightened in place and S7 is executed; otherwise, the process returns to S4; S7: After the bolt is pre-tightened, the hydraulic wrench repeats the pre-tightening action for more than 2 times to complete the automatic pre-tightening operation and wait for the next bolt pre-tightening work.

2. The automatic control method of a hydraulic wrench pump according to claim 1, characterized in that: The specific operation process of collecting the piston pressure and the no-load full return time in S3 includes the following steps: S201: Under no-load conditions, start the hydraulic wrench pump and perform initialization operations; S202: Start the pump station system to increase pressure, adjust the electromagnetic reversing valve, and retract the piston in the wrench to the bottom. The system pressure at this time is recorded as the maximum pressure P_B_max of the piston retraction; S203: Adjust the electromagnetic reversing valve to extend the piston in the wrench, and record the time t_F0 at this moment. Record the minimum system pressure during the piston extension process, which is the minimum pressure for piston extension P_F_min, and record the time t_F1 when the system pressure starts to rise; S204: When the piston is fully extended, the system pressure rises. The system pressure after stabilization is recorded as the maximum extension pressure P_F_max, and the time t_F2 when the system pressure reaches the maximum is recorded. S205: Regulate the electromagnetic reversing valve to retract the wrench piston, and record the time at this moment. The minimum pressure of the system during the piston retraction process is recorded as the minimum pressure of the piston retraction P_B_min, and the time when the system pressure starts to rise t_B1 is recorded. S206: When the system pressure reaches the maximum pressure P_B_max of the piston contraction, the time t_B2 at this moment is recorded, and the no-load full contraction time of the piston t_Back = (t_B2-t_B1) / 2-t_B0.

3. The automatic control method of a hydraulic wrench pump according to claim 1, characterized in that: In S7, when the process pre-tightening bolt reaches the maximum working pressure, the hydraulic wrench performs at least but not limited to three tightening actions at the maximum process pressure, and each tightening action is maintained for a preset time.

4. A hydraulic wrench pump system with a one-key learning function, operating according to the automatic control method of the hydraulic wrench pump according to any one of claims 1 to 3, wherein the system comprises a hydraulic unit and a control unit connected to each other, characterized in that: The hydraulic unit comprises an electromagnetic reversing valve (204), a wrench pump high-pressure relief valve (205), a hydraulic pump drive motor (206), a high-pressure pump (207) and a pressure sensor (210); The hydraulic pump drive motor (206) drives and connects to a high-pressure pump (207); the input end of the high-pressure pump (207) is connected to an oil tank (213); the output end is connected to a hydraulic wrench (201) via an electromagnetic reversing valve (204); the pressure sensor (210) is installed at the output end of the high-pressure pump (207) for monitoring the system pressure; the wrench pump high-pressure relief valve (205) is connected to the output end of the high-pressure pump (207) for setting the maximum pressure of the system according to the pre-tightening force of the bolt.

5. The hydraulic wrench pump system with one-key learning function according to claim 4, characterized in that: The hydraulic unit further comprises a wrench pump low-pressure relief valve (211), a low-pressure pump (212) and a one-way valve; the inlet side of the one-way valve is connected to the output end of the low-pressure pump (212), and the outlet side is connected to the output end of the high-pressure pump (207); the wrench pump low-pressure relief valve (211) is connected to the output end of the low-pressure pump (212) and is used to limit the opening pressure of the one-way valve, so that the one-way valve is opened when the wrench piston is unloaded.

6. The automatic control method of a hydraulic wrench pump according to claim 5, characterized in that: The hydraulic unit further comprises a return oil pressure setting relief valve (203) for setting the maximum pressure of the return stroke contraction of the piston in the hydraulic wrench. The pressure value set by the return oil pressure setting relief valve (203) is higher than the setting value of the wrench pump low-pressure relief valve (211) and lower than the setting value of the wrench pump high-pressure relief valve (205).

7. The automatic control method of a hydraulic wrench pump according to claim 4, characterized in that: The control unit comprises a wrench pump controller (102) and a wrench pump operating handle (103) which are connected to each other. The wrench pump controller (102) is electrically connected to an electromagnetic reversing valve (204), a pressure sensor (210) and a hydraulic pump drive motor (206), respectively. The wrench pump operating handle (103) is used to manually control and obtain the operating status of the wrench pump.

8. The automatic control method of a hydraulic wrench pump according to claim 7, characterized in that: The wrench pump controller (102) comprises a housing, a connector and a PCB circuit board. The PCB circuit board is installed in the housing. The connector is installed on the housing and is used to connect the system wiring harness with the PCB circuit board. The PCB circuit board is used for data transmission and communication, and detects and stores data.

9. The automatic control method of a hydraulic wrench pump according to claim 7, characterized in that: The wrench pump operating handle (103) comprises a handle body and a No. 1 button (1036), a No. 2 button (1031), a No. 3 button (1037) and an indicator light (1035) arranged on the handle body; The button No. 1 (1036) is used to control the start and stop of the pump, the button No. 2 (1031) is used to adjust the circumferential movement of the electromagnetic reversing valve (204) and one-key learning, the button No. 3 (1037) is used to control the start and stop of the automatic operation of the hydraulic wrench pump, and the indicator light (1035) is used to display the status of the one-key learning and the operating status of the pump station through multiple flashing frequencies.

10. The automatic control method of a hydraulic wrench pump according to claim 4, characterized in that: The electromagnetic reversing valve (204) is a two-position four-way electromagnetic reversing valve, a three-position four-way electromagnetic reversing valve with an M-type middle position, or a combination of two two-position three-way electromagnetic reversing valves, and is used to control the switching of the forward stroke and the return stroke of the wrench. The stable working pressure of the electromagnetic reversing valve (204) is higher than 60 MPa, and the switching frequency is greater than 10 Hz.

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