A system for controlling the extension of a crane's outrigger

Abstract

The application provides a support leg telescopic control system and a crane. The support leg telescopic control system comprises a controller, a hydraulic source module and an execution module. The hydraulic source module is connected with the controller and the execution module respectively, and is used for providing power hydraulic flow for the execution module according to the instruction of the controller. The execution module is used for executing the telescopic action of the support leg. The hydraulic source module comprises a servo motor, a high-pressure small-displacement pump, a large-displacement pump and a switching valve. The servo motor is connected with the high-pressure small-displacement pump and the large-displacement pump respectively, and is used for driving the high-pressure small-displacement pump and the large-displacement pump. The switching valve is connected with the high-pressure small-displacement pump and the large-displacement pump respectively, and is used for switching the working state of the high-pressure small-displacement pump or the large-displacement pump. The application improves the control precision of the horizontal support leg, reduces the noise, the pressure and the flow fluctuation in the hydraulic system during use, and improves the use reliability of the hydraulic system.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to a support leg telescopic control system and a crane. Background Art

[0002] The outrigger hydraulic system of a crane is an important component of the crane chassis.

[0003] The outrigger hydraulic system controls the extension of the outriggers in both horizontal and vertical directions, and is used to rigidly support the travel between the crane and the supporting surface, thereby improving the crane's working capacity and stability. By operating the outriggers, the crane can be switched between the driving state and the construction state.

[0004] In existing technical solutions, the engine directly powers the pump through the power take-off port. However, due to the instability of the engine speed, the uncertainty of manual throttle operation, and the influence of the engine's operating state, the pump speed is not constant (see patent CN 112855650 A). This mainly has the following problems:

[0005] 1. For example CN 115959586 A, Although a proportional valve and pump speed control device are used, the speed variation introduced by the engine cannot be eliminated. The adjustment lag of the variable pump displacement control mechanism can only improve the accuracy of flow control, but cannot completely solve the interference introduced by the engine.

[0006] 2. Loud noise during use;

[0007] 3. For example CN 114909350 A, The suspension hydraulic system introduces a load-sensing pump and a multi-way valve to form a load-sensing system. Since the load-sensing pump is regulated by a mechanical structure and its dynamic response is greatly affected by factors such as processing and assembly, it cannot accurately provide the required pressure for the suspension cylinder, and the pressure fluctuation is small.

[0008] 4. For example Patent CN 112855650 A, The movement of the horizontal cylinder or the vertical cylinder cannot be accurately controlled. If the horizontal outrigger is in a semi-extended working condition, it is inconvenient to align the outrigger pin control and the frame pin control. Summary of the Invention

[0009] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a support leg telescopic control system and a crane to improve the control accuracy of the horizontal support legs, reduce noise during use and pressure and flow fluctuations in the hydraulic system, and improve the reliability of the hydraulic system.

[0010] In order to achieve the above objectives / solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0011] In a first aspect, the present invention provides a leg extension and retraction control system, comprising: a controller, a hydraulic source module, and an execution module;

[0012] The hydraulic source module is connected to the controller and the execution module respectively, and is used to provide power hydraulic flow to the execution module according to the instructions of the controller;

[0013] The execution module is used to execute the leg extension and retraction action;

[0014] The hydraulic source module includes a servo motor, a high-pressure small-displacement pump, a large-displacement pump and a switching valve;

[0015] The servo motor is connected to the high-pressure small-displacement pump and the large-displacement pump respectively, and is used to drive the high-pressure small-displacement pump and the large-displacement pump;

[0016] The switching valve connects the execution module with the high-pressure small-displacement pump and the large-displacement pump respectively, and is used to switch the working state of the high-pressure small-displacement pump or the large-displacement pump, thereby providing power hydraulic flow for the execution module.

[0017] The effect of the above settings is: the hydraulic source module uses a servo motor to drive a high-pressure small-displacement pump and a large-displacement pump to replace the original engine direct adjustment solution, avoiding pump flow fluctuations caused by the engine torque, thereby improving control accuracy.

[0018] If fine flow regulation is required, it can be adjusted by adjusting the speed of the servo motor. If larger flow regulation is required, a switching valve is used.

[0019] Furthermore, the switching valve is a three-position four-way reversing valve, comprising two input ports, one output port and a control end;

[0020] The two input ports of the switching valve are connected to a high-pressure small-displacement pump and a large-displacement pump respectively;

[0021] The output port of the switching valve is connected to the execution module;

[0022] The control end of the switching valve is connected to the controller. According to the instruction of the controller, the switching valve only connects the high-pressure small-displacement pump to the execution module, or only connects the large-displacement pump to the execution module, or connects both the high-pressure small-displacement pump and the large-displacement pump to the execution module.

[0023] The effect of this setup is that the switching valve receives commands from the controller, which determines the system flow rate by determining the required speed of the operating mechanism. This determines the switching valve's position and connects the large and small displacement pumps. At low flow rates, the switching valve connects only the small displacement pump to the system. At higher flow rates, the small displacement pump is disconnected, and the large displacement pump is connected. At maximum flow demand, both pumps are connected simultaneously.

[0024] When the system requires less flow, the system is in a working condition where the pump outlet pressure needs to be maintained (when the pressure difference on both sides of servo valve 1 reaches the set value). At this time, the torque load of the motor is high and the speed is low. In order to improve the working efficiency of the system, reduce the oil film between the friction pairs of the hydraulic pump, and increase the stability of the system at low speed of the servo motor, the system only provides a small flow from the high-pressure small-displacement pump to make up for the system leakage, thereby maintaining this pressure. At the same time, the switching valve controls the large-displacement pump to switch to the unloading state.

[0025] When the system requires a larger flow rate and exceeds the flow threshold of the high-pressure, low-flow working mode, the switching valve controls the unloading of the high-pressure, low-flow pump, and gradually opens the large-displacement metering pump to supply fluid to the system. Closing the small-displacement pump can reduce the wear and tear of the high-pressure, small-displacement pump. Gradual switching can reduce system pressure and flow fluctuations.

[0026] As the system flow demand increases further, the switching valve can control the small-displacement pump to open, allowing the large and small-displacement pumps to work simultaneously, providing more flow for the system.

[0027] Furthermore, the system also includes a safety overflow valve, one end of which is connected to the switching valve, and the other end of which is connected to the oil tank.

[0028] The above settings produce the following effects: The safety relief valve acts as a safety protection in the system. When the system pressure exceeds the specified value, the safety valve opens, discharging a portion of the system flow into the oil tank, keeping the system pressure below the allowable value, thus preventing accidents caused by excessive pressure.

[0029] Furthermore, when the oil inlet pressure obtained by the pump outlet pressure sensor exceeds the set value of the safety relief valve, the controller controls the servo motor to reduce its speed.

[0030] The effect of the above settings is: the controller controls and reduces the servo motor speed when the pressure is too high, thereby reducing the overflow loss of the pump and improving the energy consumption performance of the system.

[0031] Furthermore, the execution module includes at least one group of leg units;

[0032] A group of the outrigger units includes a horizontal oil cylinder, a vertical oil cylinder, a servo valve 1 and a servo valve 2;

[0033] The horizontal oil cylinder is used to drive the horizontal legs to extend or retract; the vertical oil cylinder is used to drive the vertical legs to extend or retract;

[0034] The control end of the servo valve 1 is connected to the controller, one side of the servo valve 1 is connected to the hydraulic source module, and the other side is connected to the rod chamber and the rodless chamber of the vertical oil cylinder;

[0035] The control end of the servo valve 2 is connected to the controller. One side of the servo valve 2 is connected to the hydraulic source module, and the other side is connected to the rod chamber and the rodless chamber of the horizontal oil cylinder.

[0036] The effect of the above settings is: through servo valve 1 and servo valve 2, the controller can control the movement of the horizontal cylinder and the vertical cylinder respectively, and the control is convenient, fast, effective and direct.

[0037] Furthermore, a group of the leg units further includes a pressure sensor 1 and a pressure sensor 2;

[0038] The pressure sensor 1 is connected to the rod chamber of the horizontal oil cylinder and is connected to the controller for detecting the pressure of the rod chamber of the horizontal oil cylinder;

[0039] The second pressure sensor is connected to the rodless chamber of the horizontal oil cylinder and is connected to the controller, and is used to detect the pressure of the rodless chamber of the horizontal oil cylinder;

[0040] The controller compares the detected rod chamber pressure and rodless chamber pressure of the horizontal oil cylinder to determine the current state of the horizontal oil cylinder:

[0041] If the pressure in the rod chamber of the horizontal cylinder is greater than the pressure in the rodless chamber, the horizontal cylinder is in the retracted state;

[0042] If the pressure in the rod chamber of the horizontal cylinder is less than the pressure in the rodless chamber, the horizontal cylinder is in the extended state;

[0043] If the rod chamber pressure of the horizontal cylinder is equal to the rodless chamber pressure, the horizontal cylinder is in a stationary state;

[0044] The horizontal cylinder control instruction is compared with the current horizontal cylinder state. If they are different, the servo valve 2 is controlled to switch the oil circuit according to the horizontal cylinder control instruction.

[0045] The above setup produces the following benefits: The horizontal cylinder's rod and rodless chamber pressures are used to directly determine its current state, assisting the controller in providing feedback and adjustment, enabling precise control of the horizontal cylinder. The pressure sensor obtains pressure data within the system, ensuring proper operation of the hydraulic system and facilitating system fault diagnosis and outrigger maintenance.

[0046] Furthermore, a pump outlet pressure sensor connected to a controller is provided at the output port of the hydraulic source module for collecting the hydraulic output pressure of the hydraulic source module;

[0047] The controller compares the rod chamber pressure and rodless chamber pressure of the horizontal oil cylinder detected, selects the larger pressure, and obtains the larger pressure in the horizontal oil cylinder;

[0048] The controller calculates a real-time pressure difference based on the larger pressure in the horizontal cylinder and the hydraulic output pressure, wherein the value of the real-time pressure difference is the value of the hydraulic output pressure minus the value of the larger pressure in the horizontal cylinder;

[0049] The controller obtains the set pressure difference △p, and subtracts the real-time pressure difference from the set pressure difference △p to obtain the difference;

[0050] The horizontal cylinder pressure closed-loop control is performed based on the difference:

[0051] If the difference is negative, it means that the real-time pressure difference exceeds the set value. At this time, the controller controls to reduce the speed of the servo motor until the difference is 0;

[0052] If the difference is positive, it means that the real-time pressure difference has not reached the set value, and the controller needs to increase the speed of the servo motor until the difference is 0.

[0053] The above settings achieve this effect: By controlling the servo motor's speed based on the differential pressure, closed-loop pressure control is achieved, enabling precise control of the horizontal cylinder's movement. This closed-loop pressure control allows the pressure differential across the servo valve to be dynamically maintained within a certain range. Within this range, the servo valve's flow control accuracy is far greater than when pressure is uncontrolled.

[0054] Furthermore, a group of the leg units further includes a displacement sensor provided at the end of the horizontal cylinder for obtaining the extension length of the horizontal cylinder;

[0055] The controller obtains the set extension length of the horizontal oil cylinder and controls the valve opening of the servo valve 2 according to the difference between the extension length of the horizontal oil cylinder and the set extension length.

[0056] The effect of the above settings is: under the premise of a certain pressure difference, the valve opening of servo valve 2 is positively correlated with the displacement of the horizontal cylinder. Through the signal of the displacement sensor, the servo valve can control the displacement of the cylinder in a closed loop.

[0057] Furthermore, the system further comprises a level meter provided on the vehicle frame; the level meter is connected to the controller and is used to collect the levelness of the vehicle;

[0058] The controller controls the valve opening area of ​​the servo valve 1 according to the horizontality of the vehicle, thereby controlling the extension length of the vertical oil cylinder.

[0059] The effect of the above settings is: the valve opening of servo valve 1 is positively correlated with the displacement of the vertical cylinder. Through the signal of the level meter, the servo valve can control the displacement of the cylinder in a closed loop.

[0060] Furthermore, when the piston rod of the horizontal oil cylinder needs to be extended or retracted quickly, the controller controls the servo valve 2 to be fully opened, and the servo motor performs volume control on the flow rate of the horizontal oil cylinder;

[0061] When the piston rod of the vertical oil cylinder needs to be extended or retracted quickly, the controller controls the servo valve to fully open, and the servo motor controls the flow rate of the vertical oil cylinder by volume.

[0062] The effect of the above settings is that the servo motor controls the flow rate of the vertical cylinder to reduce the overflow loss of the system while ensuring the rapidity of the piston movement of the horizontal cylinder and the vertical cylinder.

[0063] Furthermore, the execution module includes four groups of leg units;

[0064] The horizontal cylinders include a left front horizontal cylinder, a left rear horizontal cylinder, a right front horizontal cylinder and a right rear horizontal cylinder, which are respectively distributed on the left front, left rear, right front and right rear of the frame;

[0065] The horizontal oil cylinders include a left front horizontal oil cylinder, a left rear horizontal oil cylinder, a right front horizontal oil cylinder and a right rear horizontal oil cylinder, which are respectively distributed at the left front, left rear, right front and right rear of the frame.

[0066] The effect of the above setting is: through the four groups of leg units arranged on the frame, the balance adjustment of the frame and the horizontal and vertical extension of the legs can be achieved more directly.

[0067] Furthermore, the system also includes an energy module, which is connected to the hydraulic source module and is used to supply energy to the hydraulic source module.

[0068] Furthermore, the energy module is a battery pack;

[0069] Alternatively, the energy module is a generator; a voltage stabilizer is provided between the servo motor and the generator.

[0070] The effect of the above settings: This system is essentially a pump control system. The interference factors that affect the speed in the original solution, such as the throttle and engine status, can be eliminated through the action of the voltage stabilizer and the control of the servo motor. The speed of the two fixed-displacement pumps is controlled by the servo motor, with high speed stability and fast response to the controller signal.

[0071] Furthermore, the horizontal support leg and the frame are respectively provided with corresponding pin holes, and pin shafts can be inserted into the pin holes to lock the horizontal support leg and the frame;

[0072] The horizontal legs are provided with pin holes at the fully extended position, the half extended position and the fully retracted position.

[0073] The above setup produces the following effect: The horizontal cylinder drives the horizontal outrigger to extend or retract. A first pin hole is provided on the outrigger, and a second pin hole is provided on the frame that corresponds to the first pin hole. Once the first and second pin holes are aligned, the outrigger reaches the designated position. At this point, a leg pin (shaft pin) is manually inserted between the first and second pin holes to prevent the outrigger from further horizontal movement, ensuring safety during operation. The pin insertion allows for a convenient and secure locking of the outrigger.

[0074] Furthermore, the system further includes a manipulation module connected to the controller;

[0075] The control module includes a horizontal support leg control module and a vertical support leg control module.

[0076] The horizontal outrigger control module includes: the extension and retraction buttons of the horizontal oil cylinder and the one-touch button to reach the designated position (when the water outrigger is extended to the required length and the horizontal outrigger is retracted, the vehicle enters the driving state);

[0077] The vertical outrigger control module includes: an extend button and a retract button for the vertical oil cylinder and a corresponding one-touch button to reach the designated position (to level the vehicle chassis to enter the boarding operation state and to retract the vertical oil cylinder to prepare the chassis for entering the driving state).

[0078] The buttons are virtual buttons on the screen or physical buttons or levers.

[0079] The controller can respond to the input actions of the extension button and the retraction button of the horizontal cylinder and the key to reach the specified position, and control the speed of the servo motor, the valve position of the switching valve and the valve opening area of ​​the second servo valve, so that the horizontal cylinder performs the corresponding action;

[0080] The controller can respond to the input actions of the vertical cylinder's extension button and retraction button and the one-key-to-reach-awarded-position button, control the speed of the servo motor, the valve position of the switching valve, and the valve port opening area of ​​the servo valve, so that the vertical cylinder performs corresponding actions.

[0081] The effect of the above settings is that the controller is responsible for collecting pressure, position and other signals within the system, and combining them with control signals input by the user (such as extending or retracting horizontal legs, extending or retracting vertical cylinders, the speed of horizontal or vertical cylinder movement, etc.), to control each component within the system to enable the crane to complete the preset action and move the corresponding parts to the specified position.

[0082] The vertical cylinder extends and retracts, corresponding to the rise and fall of the vehicle.

[0083] After the vehicle chassis is raised together with the upper vehicle, the crane enters the upper vehicle operation mode;

[0084] After the vehicle is lowered, the crane chassis tires touch the ground and the crane is ready to enter driving mode.

[0085] In a second aspect, the present invention provides a crane comprising a frame and a support leg extension and retraction control system as described in the first aspect, which is mounted on the frame.

[0086] Compared with the prior art, the present invention has the following beneficial effects:

[0087] 1. The present invention can improve the control accuracy of the horizontal outriggers, facilitate the alignment of the outrigger pin holes and save operation time, while reducing noise during use and pressure and flow fluctuations in the hydraulic system, thereby improving the reliability of the hydraulic system.

[0088] 2. The pressure sensor obtains the pressure data in the system, which can ensure the normal operation of the hydraulic system and facilitate the system fault diagnosis and maintenance of the outriggers;

[0089] 3 、 The maximum pressure of the hydraulic system does not exceed the setting value of the safety relief valve, thereby protecting the safety of all hydraulic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 It is the hydraulic principle diagram of the present invention;

[0091] Figure 2 It is a control logic diagram of the present invention;

[0092] Figure 3 It is a schematic diagram of the positioning of the support leg pins of the present invention;

[0093] In the picture ： 1. Left front vertical cylinder; 2. Left front horizontal cylinder; 3. Displacement sensor; 4. First pressure sensor; 5. Second pressure sensor; 6. Servo valve 2; 7. Servo valve 1; 13. Right front horizontal cylinder; 14. Right front vertical cylinder; 15. Right rear vertical cylinder; 16. Right rear horizontal cylinder; 21. Safety relief valve; 23. Switching valve; 24. High-pressure small-displacement metering pump; 25. Large-displacement metering pump; 26. Servo motor; 27. Pump outlet pressure sensor; 28. Controller; 36. Left rear horizontal cylinder; 35. Left rear vertical cylinder.

[0094] 001, vertical cylinder; 002, horizontal leg fully extended pin hole; 003, horizontal leg half extended pin hole; 004, pin hole at any position; 005, frame pin hole; 006, frame, 007, horizontal cylinder.

[0095] △p-pressure difference setting value; up1-oil inlet pressure signal; up2-servo valve outlet pressure; lz-level gauge signal; lx-displacement sensor signal. DETAILED DESCRIPTION

[0096] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0097] In the description of this embodiment, it should be noted that when terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside" appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings. It is only for the convenience of describing this embodiment and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on this embodiment.

[0098] Definition of Abbreviations:

[0099] Hydraulic power: the product of pressure and flow in the system.

[0100] Pump control system: The flow rate output by the hydraulic pump is adjusted by changing the pump displacement or the speed of the prime mover. It is also called a volume control circuit. The pressure oil output by the hydraulic pump completely enters the actuator.

[0101] Variable speed control: By changing the speed of the prime mover, the pump speed is adjusted to control the flow rate in the system.

[0102] Load matching: Open-loop control is used to control the servo motor to match the pump speed to meet the flow rate required by the load, without the need to preset the pressure difference between the pump and the maximum load.

[0103] Maintaining pressure: The hydraulic system maintains a certain pressure.

[0104] One-click: After the operator inputs a single command to the system, the system can automatically execute the set program to achieve one or more set goals. Example 1

[0105] This embodiment provides a support leg extension and retraction control system. Figure 1 As shown, it includes: a controller 28, a hydraulic source module and an execution module;

[0106] A hydraulic source module is connected to the controller 28 and the execution module respectively, and is used to provide power hydraulic flow to the execution module according to the instructions of the controller 28;

[0107] The execution module is used to execute the leg extension and retraction action.

[0108] The hydraulic source module includes a servo motor 26, a high-pressure small-displacement pump, a large-displacement pump, and a switching valve 23;

[0109] The servo motor 26 is connected to the high-pressure small-displacement pump and the large-displacement pump respectively, and is used to drive the high-pressure small-displacement pump and the large-displacement pump;

[0110] The switching valve 23 connects the execution module with the high-pressure small-displacement pump and the large-displacement pump respectively, and is used to switch the working state of the high-pressure small-displacement pump or the large-displacement pump, thereby providing power hydraulic flow for the execution module.

[0111] The hydraulic source module uses a servo motor 26 to drive a high-pressure, small-displacement pump and a large-displacement pump, replacing the existing direct engine control scheme. This avoids pump flow fluctuations caused by engine torque, thereby improving control accuracy. For fine flow control, the speed of the servo motor 26 is adjusted. For larger flow adjustments, the switching valve 23 is used.

[0112] Specifically, the switching valve 23 is a three-position four-way reversing valve, including two input ports, one output port and a control end;

[0113] The two input ports of the switching valve 23 are connected to a high-pressure small-displacement pump and a large-displacement pump respectively;

[0114] The output port of the switching valve 23 is connected to the execution module;

[0115] The control end of the switching valve 23 is connected to the controller 28. According to the instruction of the controller 28, the switching valve 23 only connects the high-pressure small-displacement pump to the execution module, or only connects the large-displacement pump to the execution module, or connects both the high-pressure small-displacement pump and the large-displacement pump to the execution module.

[0116] Switching valve 23 receives commands from controller 28, which determines the system flow rate by assessing the required speed of the operating mechanism. This determines the position of switching valve 23 and connects the large and small displacement pumps. At low flow rates, switching valve 23 connects only the small displacement pump to the system. At higher flow rates, the small displacement pump is disconnected, and the large displacement pump is connected. When flow demand is highest, both pumps are connected simultaneously.

[0117] refer to Figure 2 , when the system requires less flow, the system is in a condition where the pump outlet pressure needs to be maintained (when the pressure difference on both sides of the servo valve 7 reaches the set value). At this time, the torque load of the motor is high and the speed is low. In order to improve the working efficiency of the system, reduce the oil film between the friction pairs of the hydraulic pump, and increase the stability of the system at low speed of the servo motor 26, the system only provides a smaller flow by the high-pressure small-displacement pump to make up for the system leakage, thereby maintaining this pressure. At the same time, the switching valve 23 controls the large-displacement pump to switch to the unloading state.

[0118] When the system requires a larger flow rate and exceeds the flow threshold of the high-pressure, low-flow working mode, the switching valve 23 controls the high-pressure, low-flow pump to unload, and gradually opens the large-displacement metering pump 25 to supply liquid to the system. Closing the small-displacement pump can reduce the wear and tear of the high-pressure, low-displacement pump, and gradual switching can reduce system pressure and flow fluctuations.

[0119] As the system flow demand increases further, the switching valve 23 can control the small displacement pump to open, so that the large and small displacement pumps work at the same time, providing more flow for the system.

[0120] Preferably, the system further includes a safety relief valve 21 , one end of the safety relief valve 21 is connected to the switching valve 23 , and the other end is connected to the oil tank.

[0121] The safety relief valve 21 plays a safety protection role in the system. When the system pressure exceeds the specified value, the safety valve opens and discharges part of the flow in the system into the oil tank, so that the system pressure does not exceed the allowable value, thereby ensuring that the system does not cause accidents due to excessive pressure.

[0122] Specifically, when the oil inlet pressure obtained by the pump outlet pressure sensor 27 exceeds the set value of the safety relief valve 21, the controller 28 controls the servo motor 26 to reduce its speed.

[0123] The controller 28 controls the speed of the servo motor 26 to reduce when the pressure is too high, thereby reducing the overflow loss of the pump and improving the energy consumption performance of the system.

[0124] Specifically, the execution module includes at least one group of leg units;

[0125] A set of outrigger units includes horizontal cylinder 007, vertical cylinder 001, servo valve 1 7 and servo valve 2 6;

[0126] The horizontal oil cylinder 007 is used to drive the horizontal legs to extend or retract; the vertical oil cylinder 001 is used to drive the vertical legs to extend or retract;

[0127] The control end of the servo valve 7 is connected to the controller 28. One side of the servo valve 7 is connected to the hydraulic source module, and the other side is connected to the rod chamber and the rodless chamber of the vertical cylinder 001.

[0128] The control end of the servo valve 2 6 is connected to the controller 28 , one side of the servo valve 2 6 is connected to the hydraulic source module, and the other side is connected to the rod chamber and the rodless chamber of the horizontal cylinder 007 .

[0129] Through servo valve 1 7 and servo valve 2 6, the controller 28 can control the movement of the horizontal cylinder 007 and the vertical cylinder 001 respectively, and the control is convenient, fast, effective and direct.

[0130] Specifically, a group of outrigger units further includes a pressure sensor 1 and a pressure sensor 2;

[0131] Pressure sensor 1 is connected to the rod chamber of the horizontal oil cylinder 007 and is connected to the controller 28 for detecting the pressure of the rod chamber of the horizontal oil cylinder 007;

[0132] The second pressure sensor is connected to the rodless cavity of the horizontal oil cylinder 007 and is connected to the controller 28 for detecting the pressure of the rodless cavity of the horizontal oil cylinder 007;

[0133] The controller 28 compares the detected rod chamber pressure and rodless chamber pressure of the horizontal oil cylinder 007 to determine the current state of the horizontal oil cylinder 007:

[0134] If the pressure in the rod chamber of the horizontal oil cylinder 007 is greater than the pressure in the rodless chamber, the horizontal oil cylinder 007 is in the retracted state;

[0135] If the pressure in the rod chamber of the horizontal oil cylinder 007 is less than the pressure in the rodless chamber, the horizontal oil cylinder 007 is in the extended state;

[0136] If the pressure in the rod chamber of the horizontal oil cylinder 007 is equal to the pressure in the rodless chamber, the horizontal oil cylinder 007 is in a stationary state;

[0137] The control instruction of the horizontal oil cylinder 007 is compared with the state of the horizontal oil cylinder 007 at this time. If they are different, the servo valve 2 6 is controlled to switch the oil circuit according to the control instruction of the horizontal oil cylinder 007.

[0138] The state of the horizontal cylinder 007 at this moment can be directly judged through the rod chamber pressure and the rodless chamber pressure of the horizontal cylinder 007 , and the auxiliary controller 28 performs feedback adjustment to precisely control the horizontal cylinder 007 .

[0139] Specifically, a pump outlet pressure sensor 27 connected to a controller 28 is provided at the output port of the hydraulic source module to collect the hydraulic output pressure of the hydraulic source module;

[0140] The controller 28 compares the rod chamber pressure and rodless chamber pressure of the horizontal oil cylinder 007 detected, selects the larger pressure, and obtains the larger pressure in the horizontal oil cylinder 007;

[0141] The controller 28 calculates the real-time pressure difference based on the larger pressure in the horizontal cylinder 007 and the hydraulic output pressure. The real-time pressure difference is the value of the hydraulic output pressure minus the larger pressure in the horizontal cylinder 007.

[0142] The controller 28 obtains the set pressure difference Δp and subtracts the real-time pressure difference from the set pressure difference Δp to obtain the difference;

[0143] Perform closed-loop pressure control of horizontal cylinder 007 based on the difference:

[0144] If the difference is negative, it means that the real-time pressure difference exceeds the set value. At this time, the controller 28 controls the speed of the servo motor 26 to decrease until the difference is 0;

[0145] If the difference is positive, it means that the real-time pressure difference has not reached the set value, and the controller 28 needs to control the increase of the speed of the servo motor 26 until the difference is zero.

[0146] By controlling the speed of the servo motor 26 based on the differential pressure, closed-loop pressure control is implemented, enabling precise control of the movement of the horizontal cylinder 007. Through closed-loop pressure control, the pressure differential across the servo valve can be dynamically maintained within a certain range. Within this range, the servo valve's flow control accuracy is far greater than when pressure is uncontrolled.

[0147] Specifically, a group of outrigger units further includes a displacement sensor 3 provided at the end of the horizontal cylinder 007, for obtaining the extension length of the horizontal cylinder 007;

[0148] The controller 28 obtains the set extension length of the horizontal cylinder 007 and controls the valve opening of the servo valve 2 6 according to the difference between the extension length of the horizontal cylinder 007 and the set extension length.

[0149] Under the premise of a certain pressure difference, the valve opening of the servo valve 2 6 is positively correlated with the displacement of the horizontal cylinder 007. Through the signal of the displacement sensor 3, the servo valve can control the displacement of the cylinder in a closed loop.

[0150] The servo motor 26 adjusts the speed and accurately controls the speed of the metering pump, so that the product of the speed n and the displacement V is the value required by the system - the flow rate Q, Q = n * V. This can accurately provide the required flow to the outrigger system, reducing flow and pressure fluctuations within the system. The speed of the servo motor 26 can be matched to the load, so that the pump outlet pressure does not exceed the set pressure of the safety relief valve 21. The high-pressure oil is fully supplied to the actuator, avoiding overflow losses in the system and reducing energy consumption of the crane chassis.

[0151] Specifically, the system further includes a level meter provided on the vehicle frame 006; the level meter is connected to the controller 28 and is used to collect the levelness of the vehicle;

[0152] The controller 28 controls the valve opening area of ​​the servo valve 7 according to the levelness of the vehicle, thereby controlling the extension length of the vertical cylinder 001.

[0153] The valve opening of servo valve 7 is positively correlated with the displacement of vertical cylinder 001. Through the signal of the level meter, the servo valve can control the displacement of the cylinder in a closed loop.

[0154] Specifically, when the piston rod of the horizontal oil cylinder 007 needs to be quickly extended or retracted, the controller 28 controls the servo valve 26 to be fully open, and the servo motor 26 performs volume control on the flow rate of the horizontal oil cylinder 007;

[0155] When the piston rod of the vertical oil cylinder 001 needs to be extended or retracted quickly, the controller 28 controls the servo valve 7 to be fully opened, and the servo motor 26 controls the flow rate of the vertical oil cylinder 001 by volume.

[0156] The servo motor 26 controls the flow rate of the vertical cylinder 001 by volume, which can reduce the overflow loss of the system while ensuring the rapidity of the piston movement of the horizontal cylinder 007 and the vertical cylinder 001.

[0157] Specifically, the execution module includes four groups of leg units;

[0158] The horizontal cylinder 007 includes the left front horizontal cylinder 2, the left rear horizontal cylinder 36, the right front horizontal cylinder 13 and the right rear horizontal cylinder 16, which are respectively distributed on the left front, left rear, right front and right rear of the frame 006;

[0159] The vertical cylinder 007 includes a left front vertical cylinder 1, a left rear horizontal cylinder 35, a right front horizontal cylinder 14 and a right rear horizontal cylinder 15, which are respectively distributed at the left front, left rear, right front and right rear of the frame 006.

[0160] Through the four groups of outrigger units provided on the vehicle frame 006, the balance adjustment of the vehicle frame 006 and the horizontal and vertical extension of the outriggers can be achieved relatively directly.

[0161] Specifically, the system further includes an energy module, which is connected to the hydraulic source module and is used to supply energy to the hydraulic source module.

[0162] Specifically, the energy module is a battery pack;

[0163] Alternatively, the energy module is a generator; a voltage stabilizer is provided between the servo motor 26 and the generator.

[0164] This system is essentially a pump control system. It can eliminate interference factors such as the throttle and engine status that affect the speed in the original solution through the action of the voltage stabilizer and the control of the servo motor 26. The speed of the two fixed-displacement pumps is controlled by the servo motor 26, with high speed stability and fast speed control response to the signal of the controller 28.

[0165] like Figure 3 As shown, corresponding pin holes are provided on the horizontal support legs and the frame 006, and pin shafts can be inserted into the pin holes to lock the horizontal support legs;

[0166] The horizontal legs are provided with pin holes in the fully extended position, the half extended position and the fully retracted position.

[0167] refer to Figure 3Schematic diagram of the outrigger pin positioning. When the horizontal outrigger is in the retracted state, the fully extended pin hole 002 of the horizontal outrigger is aligned with the pin hole 005 of the frame 006, and the outrigger pin is inserted; when the horizontal outrigger is in the 50% extended working condition, the half-extended pin hole 003 of the horizontal outrigger needs to be aligned with the pin hole 005 of the frame 006, and the outrigger pin is inserted; the pin hole 004 at any position is aligned with the pin hole 005 of the frame 006, which represents the working condition of the horizontal outrigger at any extension length, and the outrigger pin also needs to be inserted.

[0168] Horizontal cylinder 007 drives the horizontal outriggers, extending or retracting them. The outriggers and frame 006 have corresponding pin holes. Once the pin holes align, the outriggers reach the designated position. Manually insert a leg pin (shaft pin) between the two pin controls to prevent further horizontal movement, ensuring safety during operation. The pin insertion allows for a secure and convenient locking of the outriggers.

[0169] Preferably, the system further comprises a manipulation module connected to the controller 28;

[0170] The control module includes: a horizontal outrigger control module and a vertical outrigger control module.

[0171] The horizontal outrigger control module includes: the extension button and retraction button of the horizontal oil cylinder 007 and the one-touch button to reach the designated position (when the water outrigger is extended to the required length and the horizontal outrigger is retracted, the vehicle enters the driving state);

[0172] The vertical outrigger control module includes: the extension button and retraction button of the vertical oil cylinder 001 and the corresponding one-touch button to reach the designated position (leveling the vehicle chassis to enter the boarding operation state and retracting the vertical oil cylinder 001 to prepare the chassis to enter the driving state).

[0173] The buttons are virtual buttons on the screen or physical buttons or levers.

[0174] The controller 28 can respond to the input of the extend and retract buttons and the one-key reach designated position button of the horizontal cylinder 007, and control the speed of the servo motor 26, the valve position of the switching valve 23, and the valve opening area of ​​the servo valve 2 6, so that the horizontal cylinder 007 performs the corresponding action;

[0175] The controller 28 can respond to the input actions of the extension button and retraction button of the vertical cylinder 001 and the one-key reach to the specified position button, control the speed of the servo motor 26, the valve position of the switching valve 23 and the valve opening area of ​​the servo valve 7, so that the vertical cylinder 001 performs the corresponding action.

[0176] The controller 28 is responsible for collecting pressure, position and other signals within the system, and combining them with the control signals input by the user (such as: extending or retracting the horizontal cylinder 007, extending or retracting the vertical cylinder 001, the speed of the horizontal or vertical cylinder 001, etc.), to control the various components within the system to enable the crane to complete the preset action and move the corresponding components to the specified position.

[0177] The vertical cylinder 001 extends and retracts, corresponding to the rise and fall of the vehicle.

[0178] After the vehicle chassis is raised together with the upper vehicle, the crane enters the upper vehicle operation mode;

[0179] After the vehicle is lowered, the crane chassis tires touch the ground and the crane is ready to enter driving mode.

[0180] Press the corresponding button and the system will execute the corresponding program until the value read by the system determines that the program is completed.

[0181] like Figure 2 As shown, the controller 28 can execute the following instructions according to the following control logic:

[0182] 1. Horizontal cylinder 007 extends - one-click extension of the horizontal legs:

[0183] ① Read the set position; ② Subtract Up1-up2 from △p. The positive or negative value is used to increase or decrease the speed of servo motor 26, thereby controlling the flow rate provided by the pump to horizontal cylinder 007; ③ Subtract the actual position from displacement sensor 3 to control the flow rate required by horizontal cylinder 007. A larger difference requires more flow, while a smaller difference requires less flow. ④ Continue until the difference between the set position and the value read by displacement sensor 3 reaches 0, completing the extension and retraction of horizontal cylinder 007.

[0184] 2. Horizontal cylinder 007 extends - one-button retraction of horizontal legs:

[0185] ① Retract the horizontal cylinder 007 ② When the difference between the displacement sensor 3 and the set position (restored position) is 0, it is determined that the horizontal cylinder 007 is retracted into position.

[0186] 3. Vertical Cylinder 001 - One-key leveling

[0187] ① Extend the vertical cylinder 001; ② Read the level value; ③ Adjust the vertical cylinder 001 to the corresponding position; ④ The level degree displays the leveling, and one-touch leveling is completed.

[0188] The leveling method is to move the level gauge to a higher position and adjust the valve opening of the servo valve 2 6 at that position accordingly.

[0189] 4. Vertical Cylinder 001 - One-button retraction

[0190] ① Retract all vertical cylinders 001 simultaneously, ② the pump outlet pressure detects that the retraction pressure reaches the set pressure of the safety relief valve 21, ③ hold for three seconds (the set time is subject to actual conditions) to ensure that all vertical cylinders 001 are retracted, ④ complete one-button retraction.

[0191] Specifically, the execution module includes horizontal legs, vertical legs and a controller 28.

[0192] The horizontal oil cylinder 007 drives the horizontal outrigger to move, which can extend or retract the horizontal outrigger. There are corresponding pin controls on the horizontal outrigger and the frame 006. After the pin controls are aligned, the horizontal outrigger reaches the specified position. At this time, a leg pin is manually inserted between the two pin controls to ensure that the horizontal outrigger will no longer move horizontally, ensuring safety during operation.

[0193] The vertical cylinder 001 extends and retracts, corresponding to the raising and lowering of the vehicle. After raising, the vehicle chassis and the upper vehicle are lifted, and the crane enters the upper vehicle operation mode; after the vehicle is lowered, the crane chassis tires touch the ground, and the crane is ready to enter the driving mode.

[0194] like Figure 2 As shown, controller 28 is responsible for collecting pressure, position, and other signals within the system. Combined with user-input control signals (such as extending or retracting the horizontal outriggers, extending or retracting the vertical cylinder 001, and the speed of the horizontal or vertical cylinder 001), it controls the various components within the system, enabling the crane to complete preset movements and move the corresponding components to designated positions. In the figure, Δp is the set pressure differential; up1 is the oil inlet pressure signal; up2 is the servo valve outlet pressure; lz is the level gauge signal; and lx is the displacement sensor signal. Example 2

[0195] This embodiment provides a support leg extension control system based on a hydraulic system. Figure 2 Control logic diagram, the entire hydraulic system is mainly divided into the following modules: energy source, hydraulic source module, execution module and controller 28 and operation module.

[0196] (1) Energy source module

[0197] Provides energy source for the hydraulic source module, acts as a prime mover, and provides the current required by the servo motor 26. And is provided with a voltage stabilizer (refer to Figure 2 ).

[0198] This system is essentially a pump control system. It can eliminate the interference factors that affect the speed in the original solution, such as the throttle and engine status, through the action of the voltage stabilizer and the control of the servo motor 26. The speed of the two quantitative pumps is controlled by the servo motor 26, with high speed stability and fast speed control response to the signal of the controller 28.

[0199] (2) Hydraulic source module:

[0200] It includes a servo motor 26 , a high-pressure small-displacement pump, a large-displacement pump and a switching valve 23 .

[0201] The rotation speed of the servo motor 26 is directly controlled by the controller 28 , thereby adjusting the rotation speeds of the two pumps.

[0202] When the system requires less flow, the system is in a working condition where the pump outlet pressure needs to be maintained (when the pressure difference on both sides of the servo valve 7 reaches the set value). At this time, the torque load of the motor is high and the speed is low. In order to improve the working efficiency of the system, reduce the oil film between the friction pairs of the hydraulic pump, and increase the stability of the system at low speed of the servo motor 26, the system only provides a smaller flow by the high-pressure small-displacement pump to make up for the system leakage, thereby maintaining this pressure. At the same time, the switching valve 23 controls the large-displacement pump to switch to the unloading state.

[0203] When the system requires a larger flow rate and exceeds the flow threshold of the high-pressure, low-flow working mode, the switching valve 23 controls the unloading of the high-pressure, low-flow pump, and gradually opens the large-displacement metering pump 25 to supply liquid to the system (closing the small-displacement pump can reduce the wear and tear of the high-pressure, small-displacement pump, and gradual switching can reduce system pressure and flow fluctuations).

[0204] As the system flow demand increases further, the switching valve 23 can control the small displacement pump to open, so that the large and small displacement pumps work at the same time, providing more flow for the system.

[0205] (3) Execution module

[0206] The execution module includes horizontal outriggers and vertical outriggers. The operator can issue control instructions to the crane chassis through the outrigger control module. The control instructions are further controlled by the controller 28 to control the operation of the components in the execution module.

[0207] refer to Figure 3 Schematic diagram of the outrigger pin positioning. When the horizontal outrigger is in the retracted state, the fully extended pin hole 002 of the horizontal outrigger is aligned with the pin hole 005 of the frame 006, and the outrigger pin is inserted; when the horizontal outrigger is in the 50% extended working condition, the half-extended pin hole 003 of the horizontal outrigger needs to be aligned with the pin hole 005 of the frame 006, and the outrigger pin is inserted; the pin hole 004 at any position is aligned with the pin hole 005 of the frame 006, which represents the working condition of the horizontal outrigger at any extension length, and the outrigger pin also needs to be inserted.

[0208] The execution module can ensure the accuracy of the displacement of the horizontal cylinder 007 when it is extended or retracted, so that the pin hole of the horizontal support is aligned with the pin hole 005 of the frame 006, which can ensure that the vertical support leg can be accurately and quickly extended or retracted to any length.

[0209] (IV) Controller 28 and Control Module

[0210] There are three closed-loop control systems in the controller 28: pressure closed-loop control, closed-loop control of the vertical cylinder 001 and the level, and closed-loop control of the horizontal cylinder 007 and the displacement sensor 3.

[0211] Pressure closed loop control: Controller 28 collects the pressure difference between the front and rear sides of the valve in real time, and the set △p is subtracted from the collected pressure difference.

[0212] ① If the difference is negative, it means that the existing pressure difference exceeds the set value. At this time, the speed of the servo motor 26 is reduced until the difference is 0;

[0213] ② If the difference is positive, it means that the existing pressure difference has not reached the set value, and the speed of the servo motor 26 needs to be increased until the difference is 0.

[0214] Through pressure closed-loop control, the pressure difference before and after the servo valve can be dynamically maintained within a certain range. Within this range, the servo valve's control accuracy over flow is much greater than the accuracy when the pressure is uncontrollable. Once the pump outlet pressure exceeds the set value of the safety relief valve 21, the speed of the servo motor 26 can be immediately reduced, thereby reducing the overflow loss of the pump and improving the energy consumption performance of the system.

[0215] Closed-loop control of vertical cylinder 001: The oil provided by the servo motor 26 and the quantitative pump system flows through the switching valve 2323 and the safety relief valve 21 to the servo valve 7 that controls the vertical cylinder 001.

[0216] (1) When the vertical cylinder 001 is required to level the vehicle body, the value of the level meter is transmitted to the controller 28, and the servo valve 7 accurately controls the valve opening area (the pressure difference on both sides of the valve is controlled by the pressure closed loop) to ensure that the flow through the servo valve controls the extension length of the vertical cylinder 001;

[0217] (2) When the piston rod of the vertical oil cylinder 001 needs to be extended or retracted quickly, the servo valve 7 is fully opened, and the servo motor 26 controls the flow rate in the volume system, thereby reducing the overflow loss of the system and ensuring the rapidity of the piston movement of the vertical oil cylinder 001.

[0218] Control of horizontal cylinder 007: When the pressure difference before and after the horizontal cylinder 007 control valve (servo valve 2 6) is constant (the pressure difference is controlled by the pressure closed loop), it forms a displacement closed-loop control system together with the displacement sensor 3 of the horizontal cylinder 007 to accurately control the displacement of the piston rod of the horizontal cylinder 007 and align any pin hole on the horizontal support leg with the pin hole on the frame 006.

[0219] When the piston rod of the horizontal oil cylinder 007 needs to be extended or retracted quickly, the servo valve 7 is fully opened, and the servo motor 26 controls the flow rate in the volume system, reducing the overflow loss of the system while ensuring the rapidity of the piston movement of the vertical oil cylinder 001.

[0220] The control module includes: a horizontal outrigger control module and a vertical outrigger control module.

[0221] The horizontal outrigger control module includes: the extension button and retraction button of the horizontal oil cylinder 007 and the corresponding one-button to reach the specified position (the water outrigger is extended to the required length and the horizontal outrigger is retracted, and the vehicle enters the driving state);

[0222] The vertical outrigger control module includes: the extension button and retraction button of the vertical cylinder 001 and the corresponding one-button to reach the specified position (leveling the vehicle chassis to enter the boarding operation state and retracting the vertical cylinder 001 to prepare the chassis to enter the driving state).

[0223] The buttons are virtual buttons on the screen or physical buttons or levers.

[0224] Press the corresponding button and the system will execute the corresponding program until the value read by the system determines that the program is completed.

[0225] 1. Horizontal cylinder 007 extends - one-click extension of the horizontal legs:

[0226] ① Read the set position; ② Subtract Up1-up2 from △p. The positive or negative value is used to increase or decrease the speed of servo motor 26, thereby controlling the flow rate provided by the pump to horizontal cylinder 007; ③ Subtract the actual position from displacement sensor 3 to control the flow rate required by horizontal cylinder 007. A larger difference requires more flow, while a smaller difference requires less flow. ④ Continue until the difference between the set position and the value read by displacement sensor 3 reaches 0, completing the extension and retraction of horizontal cylinder 007.

[0227] 2. Horizontal cylinder 007 extends - one-button retraction of horizontal legs:

[0228] ① Retract the horizontal cylinder 007 ② When the difference between the displacement sensor 3 and the set position (restored position) is 0, it is determined that the horizontal cylinder 007 is retracted into position.

[0229] 3. Vertical Cylinder 001 - One-key leveling

[0230] ① Extend the vertical cylinder 001; ② Read the level value; ③ Adjust the vertical cylinder 001 to the corresponding position; ④ The level degree displays the leveling, and one-touch leveling is completed.

[0231] 4. Vertical Cylinder 001 - One-button retraction

[0232] ① Retract all vertical cylinders 001 simultaneously, ② the pump outlet pressure detects that the retraction pressure reaches the set pressure of the safety relief valve 21, ③ hold for three seconds (the set time is subject to actual conditions) to ensure that all vertical cylinders 001 are retracted, ④ complete one-button retraction.

[0233] The closed-loop control of the oil cylinder displacement is an existing and mature technology and will not be elaborated on here.

[0234] This system is essentially a pump control system. It can eliminate interference factors such as the throttle and engine status that affect the speed in the original solution through the action of the voltage stabilizer and the control of the servo motor 26. The speed of the two fixed-displacement pumps is controlled by the servo motor 26, with high speed stability and fast speed control response to the signal of the controller 28.

[0235] This system can accurately control the flow rate and the displacement of the horizontal cylinder 007. Through program settings, the extension length of the horizontal cylinder 007 can be accurately controlled. The horizontal legs can be extended to the set position with one click, which can realize the function of quickly, accurately and automatically deploying the chassis. After pressing the one-touch retraction button, all the horizontal legs can be automatically retracted, allowing the vehicle to enter the driving state, greatly saving operation time.

[0236] This system can accurately control the flow and precisely control the displacement of the vertical cylinder 001. Through program settings, it can automatically extend the vertical cylinder 001 to support the vehicle and achieve the function of leveling the vehicle; it can automatically retract all vertical cylinders 001 to achieve a one-button retraction function, greatly reducing adjustment time;

[0237] The application of high-pressure and low-flow pumps can solve the problem of poor working stability and low motor efficiency at low speed when the servo motor 26 is in a hydraulic system with high pressure and low flow, reducing the oil film of the friction pair of the pump; the dual pumps in parallel can provide sufficient flow;

[0238] This system can accurately provide the required flow to the outrigger system, reducing flow and pressure fluctuations within the system. The speed of the servo motor 26 can be matched to the load, so that the pump outlet pressure will not exceed the set pressure of the safety relief valve 21. The high-pressure oil is fully supplied to the actuator, avoiding overflow losses within the system and reducing energy consumption of the crane chassis.

[0239] Some existing vehicle chassis use load-sensing pumps (or electro-hydraulic proportional pumps). With this system, they can be replaced with two large and small displacement fixed-displacement pumps, reducing the purchase cost of the pumps.

[0240] The pressure sensor obtains the pressure data in the system, which can ensure the normal operation of the hydraulic system and facilitate the system fault diagnosis and maintenance of the outriggers;

[0241] Traditional cranes rely solely on diesel engines, which are noisy. This invention combines the diesel engine with a generator, allowing the engine to operate in its most efficient and quiet operating range, thus reducing noise. This is similar to the working principle of a range-extended vehicle. This invention addresses the problem of high noise levels in traditional cranes using diesel engines as prime movers.

[0242] The maximum pressure of the hydraulic system does not exceed the setting value of the safety relief valve 21, thereby protecting the safety of all hydraulic components. Example 3

[0243] This embodiment provides a crane, including a frame 006 and a leg extension and retraction control system as described in the first embodiment, which is installed on the frame 006 .

[0244] In other embodiments, the present invention may also adopt the following alternatives:

[0245] 1) The metering pump can be a gear pump or a vane pump.

[0246] 2) The energy source may be a diesel engine, or it may be directly plugged in or a battery to provide current to the servo motor 26 .

[0247] 3) Due to the symmetry of the outrigger structure, the outrigger can be divided into two control groups, front and rear, and the four groups of pressure sensors at the 001A port of the horizontal and vertical cylinders can be reduced to two groups.

[0248] 4) The two metering pumps can be driven by two servo motors 26 respectively, which can eliminate the switching valve 23 and add controllable variables to the switching control strategy of the two pumps (the timing and speed of switching will affect the stability of pressure and flow in the system), bringing flexibility to the control of the system.

[0249] 5) The servo valve can be replaced with a proportional valve or a switch valve, and the pressure difference on both sides of the valve port (or damping port) can be adjusted by the original components in the hydraulic source module to ensure the flow of the actuator module in the input system.

[0250] 6) The fixed displacement pump can also be a variable displacement pump, providing the system with more controllable parameters and further improving the system's adaptability to complex working conditions.

[0251] 7) The control of the horizontal cylinder 007 can also be: ① The hydraulic source module makes the pressure difference before and after the control valve constant, and the valve performs open-loop control of the horizontal cylinder 007 (no displacement sensor 3 is required); ② The valve and the horizontal cylinder 007 displacement sensor 3 form a displacement closed-loop control system, and the hydraulic source module is not required to control the pressure difference (only flow is provided).

[0252] The crane outrigger control system of this embodiment can solve the following technical problems:

[0253] ① In order to allow the horizontal legs to be fully extended, half extended or any other extension length, the displacement can be accurately controlled to save adjustment time during operation.

[0254] ②The vertical legs can be extended or retracted to any length quickly and accurately, greatly reducing the operator's operating time;

[0255] ③Dual pump system can provide more sufficient flow;

[0256] ④ The servo motor 26 is used to control the speed. When the system pressure reaches the set value, the motor speed is reduced, which indirectly reduces the overflow loss in the hydraulic system and solves the problem of energy consumption of the crane chassis.

[0257] ⑤ When the motor of a single fixed displacement pump is running at low speed, but the system needs to maintain a certain pump outlet pressure, the system pressure is relatively high and the load on the motor is also relatively large. This causes the motor to operate at low speed and high torque, resulting in low efficiency and increased wear of the hydraulic pump. Therefore, a high-pressure, small-displacement pump is required to maintain the system pressure.

[0258] ⑥Solve the problem of loud noise during use;

[0259] ⑦ Solve the problem of flow and pressure fluctuations caused by various factors such as throttle, temperature and engine status

[0260] ⑧The fixed displacement pump can reduce the purchase cost of the variable displacement pump (load sensing pump, pump with solenoid valve control, etc.) in the traditional outrigger control hydraulic system.

[0261] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0262] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0263] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0264] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. Throughout this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0265] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A leg extension and retraction control system, characterized in that: include: Controller, hydraulic source module and execution module; The hydraulic source module is connected to the controller and the execution module respectively, and is used to provide power hydraulic flow to the execution module according to the instructions of the controller; The execution module is used to execute the leg extension and retraction action; The hydraulic source module includes a servo motor, a high-pressure small-displacement pump, a large-displacement pump and a switching valve; The servo motor is connected to the high-pressure small-displacement pump and the large-displacement pump respectively, and is used to drive the high-pressure small-displacement pump and the large-displacement pump; The switching valve connects the execution module with the high-pressure small-displacement pump and the large-displacement pump, respectively, and is used to switch the working state of the high-pressure small-displacement pump or the large-displacement pump, thereby providing power hydraulic flow to the execution module; The switching valve is a three-position four-way directional valve, comprising two input ports, one output port and a control end; The two input ports of the switching valve are connected to a high-pressure small-displacement pump and a large-displacement pump respectively; The output port of the switching valve is connected to the execution module; The control end of the switching valve is connected to the controller, and the switching valve connects only the high-pressure small-displacement pump to the execution module, only the large-displacement pump to the execution module, or both the high-pressure small-displacement pump and the large-displacement pump to the execution module according to the instruction of the controller; The execution module includes at least one group of leg units; One set of said leg units includes a horizontal cylinder; A pump outlet pressure sensor connected to a controller is provided at the output port of the hydraulic source module for collecting the hydraulic output pressure of the hydraulic source module; The controller compares the rod chamber pressure and rodless chamber pressure of the horizontal oil cylinder detected, selects the larger pressure, and obtains the larger pressure in the horizontal oil cylinder; The controller calculates a real-time pressure difference based on the larger pressure in the horizontal cylinder and the hydraulic output pressure, wherein the value of the real-time pressure difference is the value of the hydraulic output pressure minus the value of the larger pressure in the horizontal cylinder; The controller obtains the set pressure difference △p, and subtracts the real-time pressure difference from the set pressure difference △p to obtain the difference; The horizontal cylinder pressure closed-loop control is performed based on the difference: If the difference is negative, it means that the real-time pressure difference exceeds the set value. At this time, the controller controls to reduce the speed of the servo motor until the difference is 0; If the difference is positive, it means that the real-time pressure difference has not reached the set value, and the controller needs to increase the speed of the servo motor until the difference is 0.

2. The outrigger extension and retraction control system according to claim 1, characterized in that: The system further comprises a safety relief valve, one end of which is connected to the switching valve and the other end is connected to the oil tank; When the oil inlet pressure obtained by the pump outlet pressure sensor exceeds the set value of the safety relief valve, the controller controls the servo motor to reduce the speed.

3. The outrigger extension and retraction control system according to claim 1, characterized in that: A group of the outrigger units further includes a vertical oil cylinder, a servo valve 1 and a servo valve 2; The horizontal oil cylinder is used to drive the horizontal legs to extend or retract; the vertical oil cylinder is used to drive the vertical legs to extend or retract; The control end of the servo valve 1 is connected to the controller, one side of the servo valve 1 is connected to the hydraulic source module, and the other side is connected to the rod chamber and the rodless chamber of the vertical oil cylinder; The control end of the servo valve 2 is connected to the controller. One side of the servo valve 2 is connected to the hydraulic source module, and the other side is connected to the rod chamber and the rodless chamber of the horizontal oil cylinder.

4. The outrigger extension and retraction control system according to claim 3, characterized in that: A group of the leg units further includes a pressure sensor 1 and a pressure sensor 2; The pressure sensor 1 is connected to the rod chamber of the horizontal oil cylinder and is connected to the controller for detecting the pressure of the rod chamber of the horizontal oil cylinder; The second pressure sensor is connected to the rodless chamber of the horizontal oil cylinder and is connected to the controller, and is used to detect the pressure of the rodless chamber of the horizontal oil cylinder; The controller compares the detected rod chamber pressure and rodless chamber pressure of the horizontal oil cylinder to determine the current state of the horizontal oil cylinder: If the pressure in the rod chamber of the horizontal cylinder is greater than the pressure in the rodless chamber, the horizontal cylinder is in the retracted state; If the pressure in the rod chamber of the horizontal cylinder is less than the pressure in the rodless chamber, the horizontal cylinder is in the extended state; If the rod chamber pressure of the horizontal cylinder is equal to the rodless chamber pressure, the horizontal cylinder is in a stationary state; The horizontal cylinder control instruction is compared with the current horizontal cylinder state. If they are different, the servo valve 2 is controlled to switch the oil circuit according to the horizontal cylinder control instruction.

5. The outrigger extension and retraction control system according to claim 3, characterized in that: A group of the leg units further includes a displacement sensor provided at the end of the horizontal cylinder for obtaining the extension length of the horizontal cylinder; The controller obtains the set extension length of the horizontal cylinder and controls the valve opening of the servo valve 2 according to the difference between the extension length of the horizontal cylinder and the set extension length; and / or, The system also includes a level meter arranged on the vehicle frame; the level meter is connected to the controller and is used to collect the levelness of the vehicle; the controller controls the valve port opening area of ​​the servo valve 1 according to the levelness of the vehicle, thereby controlling the extension length of the vertical cylinder.

6. The outrigger extension and retraction control system according to claim 3, characterized in that: When the piston rod of the horizontal oil cylinder needs to be extended or retracted quickly, the controller controls the servo valve 2 to fully open, and the servo motor controls the flow rate of the horizontal oil cylinder; When the piston rod of the vertical oil cylinder needs to be extended or retracted quickly, the controller controls the servo valve to fully open, and the servo motor controls the flow rate of the vertical oil cylinder by volume.

7. The outrigger extension and retraction control system according to claim 3, characterized in that: The execution module includes four groups of leg units; The horizontal cylinders include a left front horizontal cylinder, a left rear horizontal cylinder, a right front horizontal cylinder and a right rear horizontal cylinder, which are respectively distributed on the left front, left rear, right front and right rear of the frame; The vertical oil cylinders include a left front vertical oil cylinder, a left rear vertical oil cylinder, a right front vertical oil cylinder and a right rear vertical oil cylinder, which are respectively distributed on the left front, left rear, right front and right rear of the frame.

8. A crane comprising a frame and the outrigger telescopic control system according to any one of claims 1 to 7 mounted on the frame.

Images