阅读说明：本技术 一种解决起重机回转启动冲击的控制系统及方法 (Control system and method for solving rotation starting impact of crane ) 是由 艾超 陈俊翔 祝瑞瀚 孟俊晓 张琳 吴璇 姜述辉 郭佳伟 于 2021-09-24 设计创作，主要内容包括：本发明涉及一种解决起重机回转启动冲击的控制系统及方法,包括先导电手柄、控制器、比例减压阀、齿轮泵、溢流阀、发动机、三位五通电液比例换向阀、单向阀、液压马达、安全阀、负载和液压油箱；在起重机回转平台启动阶段,启动前通过计算回转平台转动惯量,根据经验选取回转平台角加速度,从而可通过理论计算出启动阶段的启动压力,此最大压力对应启动阶段的阀口开度,当阀芯运动到对应压力的阀口开度时,对控制阀芯的控制信号进行定值延时,当回转平台开始转动时,定值延时时间结束,控制器输出原控制信号曲线,即阀口开度与负载进行匹配。本发明通过解决不同负载与阀口的匹配问题,可有效的解决负载不同时压力超调与流量上升曲线不一致的问题。(The invention relates to a control system and a method for solving the rotary starting impact of a crane, which comprises a conductive handle, a controller, a proportional pressure reducing valve, a gear pump, an overflow valve, an engine, a three-position five-way electro-hydraulic proportional reversing valve, a one-way valve, a hydraulic motor, a safety valve, a load and a hydraulic oil tank; in the starting stage of the rotary platform of the crane, before starting, the rotary platform rotational inertia is calculated, and the angular acceleration of the rotary platform is selected according to experience, so that the starting pressure in the starting stage can be calculated theoretically, the maximum pressure corresponds to the opening degree of a valve port in the starting stage, when a valve core moves to the opening degree of the valve port corresponding to the pressure, the control signal of the control valve core is delayed in a fixed value, when the rotary platform starts to rotate, the fixed value delay time is finished, and the controller outputs an original control signal curve, namely the opening degree of the valve port is matched with the load. The invention can effectively solve the problem that the pressure overshoot and the flow rising curve are inconsistent when the loads are different by solving the matching problem of different loads and valve ports.)

1. The utility model provides a solve control system that hoist gyration was started and is strikeed which characterized in that: the system comprises a hydraulic mechanism and a control mechanism;

the hydraulic mechanism comprises a first proportional pressure reducing valve, a second proportional pressure reducing valve, an overflow valve, a gear pump, an engine, a three-position five-way electro-hydraulic reversing valve, a first check valve, a second check valve, a first safety valve, a second safety valve, a hydraulic motor, a load and a hydraulic oil tank; the engine is connected with the gear pump; the gear pump is connected with the hydraulic oil tank; the gear pump is used for supplying oil to the hydraulic mechanism, the first proportional pressure reducing valve and the second proportional pressure reducing valve; the overflow valve is connected between the gear pump and the first proportional pressure reducing valve and the second proportional pressure reducing valve, and plays a role of a safety protection system; the first proportional pressure reducing valve and the second proportional pressure reducing valve are respectively connected with a pilot end of the three-position five-way electro-hydraulic reversing valve through a hydraulic pipeline; the first one-way valve and the second one-way valve are respectively connected with loops on the left side and the right side of the hydraulic motor, and are connected with a hydraulic oil tank; the first safety valve and the second safety valve are respectively connected with loops on the left side and the right side of the hydraulic motor, and are both connected with a hydraulic oil tank; the hydraulic motor is connected with a load;

the control mechanism comprises a conductive handle and a controller; the first conductive handle is connected with the controller through a signal wire; the controller is respectively connected with the first proportional pressure reducing valve and the second proportional pressure reducing valve and controls the first proportional pressure reducing valve and the second proportional pressure reducing valve through electric signals.

2. A control method using the system of claim 1, the method comprising the steps of: firstly, before a rotary pilot handle acts, a controller extracts load, angle and arm length parameters of a rotary platform to calculate the rotary inertia J of the rotary platform, the displacement V of a rotary quantitative motor is a fixed value, the angular acceleration alpha of the rotary platform is set to be a fixed value according to experience, the pressure required for overcoming the current load is calculated according to a formula Jg alpha Vg delta P, the flow Q output by a gear pump is a fixed value, and a flow coefficient C is a flow coefficient_dTaking a certain value, adopting bypass throttling speed regulation for the oil inlet according to a formulaThe valve port flow area A of the three-position five-way electro-hydraulic reversing valve can be calculated, and the valve core displacement X at the moment can be obtained according to a relation curve between the valve port flow area and the valve core displacement, wherein P is represented in the formula_SThe pressure of the outlet of the gear pump is the pressure P of the outlet of the gear pump when the pressure loss of the valve port of the three-position five-way electro-hydraulic reversing valve is ignored_SThe current signal I corresponding to the current valve core displacement X is obtained according to a relation curve between the valve core displacement X of the three-position five-way electro-hydraulic reversing valve and the given current I of the reducing valve; when the first conductive handle is quickly pushed to the maximum position, the controller records the current track converted by the voltage of the first conductive handle, and simultaneously outputs the current track operated by the operating hand, and when the current track is output to the current signal corresponding to the valve core displacement X calculated beforeAnd I, performing constant value delay on the current output by the controller at the time, and outputting the previously recorded current track to the pressure reducing valve by the controller when the delay time is over.

Technical Field

The invention relates to the technical field of engineering, in particular to a control system and a control method for solving the problem of rotation starting impact of a crane.

Background

With the rise of the infrastructure construction industry, engineering machinery is increasingly applied, wherein the automobile crane is widely used due to the advantages of convenience in movement, strong flexibility and the like.

The automobile crane mainly comprises a lifting arm, an amplitude variation arm, a rotation arm and an automobile chassis. The development of mobile cranes has been promoted by the development of hydraulic technology, the electronics industry, high strength steel and the automotive industry. Self-heavy, mechanically driven mobile cranes with long work preparation times have been replaced by hydraulic mobile cranes.

The hydraulic system of the hydraulic automobile crane adopts a hydraulic pump and a quantitative or variable motor to realize the independent or combined action of the lifting rotation, the amplitude variation, the boom extension and the landing leg extension of the crane. The rotary table and the underframe of the hydraulic automobile crane are connected by a slewing bearing which can bear vertical load, horizontal load and overturning moment. In order to prevent the rotating platform from sliding during running, a rotating platform locking device is arranged. The rotary mechanism is driven by a quantitative motor. The output gear of the slewing mechanism is meshed with the slewing bearing gear. The revolving platform of the crane can revolve 360 degrees along the revolving center.

Like other cranes, hydraulic truck cranes also require measures or devices to prevent the hydraulic motor from being driven by the hoist or boom over-speed. In the starting stage, due to the difference of the rotational inertia, the problem of pressure impact in the starting stage is easily caused, so that the stability in the rotation process is reduced, and meanwhile, due to the pressure impact in the starting stage, the angular acceleration in the starting stage of the crane is different under the condition that a signal is given by the same handle, namely the rotating speeds of the rotary platform in the starting stage are inconsistent. That is, if there is a forward stroke and a swing in the starting stage in the swing operation of the truck crane, the operation efficiency is lowered and a potential safety hazard is also caused, so that it is necessary to suppress the swing operation.

At present, relevant patents exist at home and abroad to carry out a series of researches on the technology for restraining the rotary forward rush and the swing of the automobile crane.

In japanese patent JP2001080879, hitachi electromechanical industrial co-company, japan proposes a crane suspension mechanism swing prevention control method. The swing position change of the crane is suppressed by limiting the area in which the swing prevention control is performed in the swing angle and swing angular velocity phase plane. A swing preventive control area in a swing angle theta and a swing angle speed theta'/omega phase plane is limited to suppress a position change of the crane without increasing a remaining swing. However, the method does not fundamentally regulate and control the pressure impact in the rotary system, meanwhile, the production cost is increased by arranging the angular velocity sensor, and the whole device is easily damaged by long-time energy loss.

In chinese patent CN107355437A, the anglo willow crane limited company has proposed a load-sensitive rotary buffer valve and a crane rotary hydraulic system. The middle way of the rotary reversing valve is sequentially connected with a pilot oil port of a three-way pressure compensation valve and an oil inlet of a constant flow valve through an LS feedback oil way, the oil inlet of the three-way pressure compensation valve is communicated with the oil inlet of a valve body, the oil outlet of the three-way pressure compensation valve is communicated with an oil return port of the valve body, the oil outlet of the constant flow valve is divided into two ways, one way is directly connected with the oil return port of the valve body, the other way is simultaneously communicated with the oil inlets of a first one-way valve and a second one-way valve, the three-way pressure compensation valve and the rotary reversing valve form a speed regulating valve, so that the flow regulation of two working oil ports A and B is realized, the flow is output in proportion and is not influenced by the load size, the whole operation process is stable in action, the speed can not be neglected, the stable opening is realized, the pressure impact is small when the crane stops, and the crane does not swing in a rotary mode. However, this method only redistributes the flow by means of pressure compensation and does not fundamentally solve the slewing motion.

In chinese patent CN108116988A, the building profession and technology college of Jiangsu provides a control method for reducing impact of stopping rotation of an automobile crane, the method sets a discrete state set of a rotation mechanism motion state and a discrete action set of a control signal ramp change step length, divides the motion state of a rotation process into corresponding state sets, divides the ramp change step length of a proportional solenoid valve control signal into corresponding action sets, detects a pressure impact value by arranging a pressure sensor at an oil inlet and an oil outlet of a rotation hydraulic motor, rewards each step of action by a reward function, and reversely updates a total reward matrix of actions in each state, so as to realize automatic learning according to an actual effect, automatically identify a state in subsequent operations, select an action sequence with the maximum total reward in a current state, and construct a ramp curve in sections for output control. The method can effectively reduce the hydraulic impact in the process of the rotation stop of the automobile crane, has stronger environmental adaptability and improves the working performance of the system; however, the working condition of the crane is severe, the production cost is increased by adding the pressure sensor, and adverse effects can be caused when the pressure sensor breaks down.

In summary, most of the existing methods for controlling the pressure overshoot of the slewing system of the automobile crane form a closed-loop control algorithm to regulate and control the slewing oscillation on the premise of adding various pressure and angular velocity sensors. In order to overcome the technical defects, a novel method for controlling the pressure overshoot of the rotary system of the automobile crane is urgently needed.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a control system and a control method for solving the rotary starting impact of a crane, which can fundamentally solve the problems of pressure overshoot in the starting stage of a rotary system of the crane and inconsistent flow rising curves under different working conditions when the tracks of handles are the same on the basis of not changing the existing hydraulic system of the crane

The technical scheme adopted by the invention is as follows:

the invention provides a control system and a method for solving the rotation starting impact of a crane, wherein the system comprises a hydraulic mechanism and a control mechanism;

the hydraulic mechanism comprises a first proportional pressure reducing valve, a second proportional pressure reducing valve, an overflow valve, a gear pump, an engine, a three-position five-way electro-hydraulic reversing valve, a first check valve, a second check valve, a first safety valve, a second safety valve, a hydraulic motor, a load and a hydraulic oil tank; the engine is connected with the gear pump; the gear pump is connected with the hydraulic oil tank; the gear pump is used for supplying oil to the hydraulic mechanism, the first proportional pressure reducing valve and the second proportional pressure reducing valve; the overflow valve is connected between the gear pump and the first proportional pressure reducing valve and the second proportional pressure reducing valve, and plays a role of a safety protection system; the first proportional pressure reducing valve and the second proportional pressure reducing valve are respectively connected with a pilot end of the three-position five-way electro-hydraulic reversing valve through a hydraulic pipeline; the first one-way valve and the second one-way valve are respectively connected with loops on the left side and the right side of the hydraulic motor, and are connected with a hydraulic oil tank; the first safety valve and the second safety valve are respectively connected with loops on the left side and the right side of the hydraulic motor, and are both connected with a hydraulic oil tank; the hydraulic motor is connected with a load;

the control mechanism comprises a conductive handle and a controller; the first conductive handle is connected with the controller through a signal wire; the controller is respectively connected with the first proportional pressure reducing valve and the second proportional pressure reducing valve and controls the first proportional pressure reducing valve and the second proportional pressure reducing valve through electric signals.

Further, the method comprises the following steps: firstly, before the action of a rotary pilot handle, a controller extracts the load, the angle and the arm length parameters of the rotary platform to calculate the rotary inertia J of the rotary platform, and the rotary quantitative motor rotatesThe displacement V is a fixed value, the angular acceleration alpha of the rotary platform is set to be a fixed value according to experience, the pressure required for overcoming the current load is calculated according to the formula Jg alpha Vg delta P, the flow Q output by the gear pump is a fixed value, and the flow coefficient C is_dTaking a certain value, adopting bypass throttling speed regulation for the oil inlet according to a formulaThe valve port flow area A of the three-position five-way electro-hydraulic reversing valve can be calculated, and the valve core displacement X at the moment can be obtained according to a relation curve between the valve port flow area and the valve core displacement, wherein P is represented in the formula_SThe pressure of the outlet of the gear pump is the pressure P of the outlet of the gear pump when the pressure loss of the valve port of the three-position five-way electro-hydraulic reversing valve is ignored_SThe current signal I corresponding to the current valve core displacement X is obtained according to a relation curve between the valve core displacement X of the three-position five-way electro-hydraulic reversing valve and the given current I of the reducing valve; when the first conductive handle is quickly pushed to the maximum position, the controller records a current track converted by the voltage of the first conductive handle, outputs the current track operated by an operating hand, and when the current signal I corresponding to the valve core displacement X calculated before is output, the current output by the controller is delayed at the value by a fixed value, and when the delay time is over, the controller outputs the previously recorded current track to the pressure reducing valve.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, different valve port openings are calculated through the rotary inertia under different working conditions, and the corresponding controller output current value under the valve port opening is taken as a constant value delay current value, so that on one hand, the pressure overshoot at the starting stage of the rotary platform is reduced, on the other hand, the flow rising curves at the starting stage of the rotary mechanism are kept consistent under the same handle input signal under different loads, and meanwhile, the rapidity and the reliability in the control process are ensured;

2. the invention does not modify the hydraulic system, but only operates in the controller, thereby ensuring the integrity and reliability of the original system.

Drawings

FIG. 1 is a schematic diagram of a control system according to the present invention;

FIG. 2 is a schematic flow chart of a control method according to the present invention;

FIG. 3 is a schematic diagram of a current trace according to the present invention.

Wherein, the reference numbers: 1-conducting the handle first; 2-a controller; 3-a first proportional pressure relief valve; 4-a second proportional pressure reducing valve; 5-an overflow valve; 6-gear pump; 7-an engine; 8-three-position five-way electro-hydraulic reversing valve; 9-a first one-way valve; 10-a second one-way valve; 11-a first safety valve; 12-a second safety valve; 13-a hydraulic motor; 14-load; 15-hydraulic oil tank.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Referring to fig. 1 to 3, a specific solution of an embodiment of a control system and method for solving the slewing start shock of a crane according to the present invention is shown. As shown in figure 1, the system comprises a hydraulic mechanism and a control mechanism, and can solve the problems that the rotation starting pressure of the crane is large in overshoot and flow rising curves are inconsistent under different working conditions.

The hydraulic mechanism comprises a first proportional pressure reducing valve 3, a second proportional pressure reducing valve 4, an overflow valve 5, a gear pump 6, an engine 7, a three-position five-way electro-hydraulic reversing valve 8, a first check valve 9, a second check valve 10, a first safety valve 11, a second safety valve 12, a hydraulic motor 13, a load 14 and a hydraulic oil tank 15; the engine 7 is connected with the gear pump 6; the gear pump 6 is connected with a hydraulic oil tank 15; the gear pump 6 is used for supplying oil to the hydraulic mechanism and the first proportional pressure reducing valve 3 and the second proportional pressure reducing valve 4; the overflow valve 5 is connected between the gear pump 6 and the first proportional pressure reducing valve 3 and the second proportional pressure reducing valve 4, and plays a role of a safety protection system; the first proportional pressure reducing valve 3 and the second proportional pressure reducing valve 4 are respectively connected with a pilot end of a three-position five-way electro-hydraulic reversing valve 8 through hydraulic pipelines; the first one-way valve 9 and the second one-way valve 10 are respectively connected with loops at the left side and the right side of a hydraulic motor 13, and meanwhile, the first one-way valve 9 and the second one-way valve 10 are both connected with a hydraulic oil tank 15; the first safety valve 11 and the second safety valve 12 are respectively connected with loops at the left side and the right side of a hydraulic motor 13, and the first safety valve 11 and the second safety valve 12 are both connected with a hydraulic oil tank 15; the hydraulic motor 13 is connected to a load 14.

The control mechanism comprises a conductive handle 1 and a controller 2; the first conductive handle 1 is connected with the controller 2 through a signal wire; the controller 2 is connected to the first proportional pressure reducing valve 3 and the second proportional pressure reducing valve 4, respectively, and controls the first proportional pressure reducing valve 3 and the second proportional pressure reducing valve 4 by electric signals.

When the first conductive handle 1 acts rapidly, the controller 2 converts the voltage signal of the first conductive handle 1 into a corresponding current signal and outputs the current signal to the first proportional pressure reducing valve 3 or the second proportional pressure reducing valve 4, the first proportional pressure reducing valve 3 or the second proportional pressure reducing valve 4 applies the pressure after pressure reduction to the left end pilot or the right end pilot of the three-position five-way electro-hydraulic reversing valve 8, at the moment, the valve core of the three-position five-way electro-hydraulic reversing valve 8 is gradually opened, the oil inlet path of the three-position five-way electro-hydraulic reversing valve 8 adopts a bypass throttling mode, namely, the throttling mode of the P-T valve port is adopted to regulate the load pressure, the flow does not gradually rise in the process of opening the valve core, i.e. the hydraulic motor 13 is not rotating, said hydraulic motor 13 needs to overcome the resistance torque of the load 14, at which time the flow required is small and negligible. In the process of overcoming the resistance moment of the load 14, the valve port of the three-position five-way electro-hydraulic reversing valve 8 is in the process of gradually opening, the opening degree of the P-T valve port at the moment is not matched with the current load, namely the load pressure generated by throttling through the P-T valve port at the moment is greater than the pressure required for overcoming the current load, and the pressure overshoot is caused in the starting stage of the crane slewing mechanism. On the other hand, the angular acceleration alpha at the starting stage is different due to mismatching of the pressure, so that the flow rising curves of the crane rotary platform under different working conditions are inconsistent under the same handle track.

In view of the above problems, the present invention further provides a control system and method for solving the slewing start impact of a crane, as shown in fig. 2, the method specifically includes the following steps:

firstly, after a crane determines a working condition, inputting a load parameter, an angle parameter between a telescopic arm and the ground and an arm length parameter into a controller 2, calculating the rotational inertia J of a rotary platform by the controller 2, setting the displacement V of a hydraulic quantitative motor to be a certain value, setting the angular acceleration alpha of the rotary platform to be a certain value according to experience, calculating the differential pressure delta P at the moment according to a formula Jg alpha Vg delta P, wherein the hydraulic motor 13 does not rotate until the hydraulic motor 13 completely overcomes the resistance moment of a load 14, and the differential pressure delta P at the moment is the pressure P at the high pressure side of the hydraulic motor 13_AThis P is_AI.e. the minimum pressure required by the hydraulic motor 13 to overcome the resistive torque of this load 14; when the pressure loss of the valve port from the port P to the high pressure port of the hydraulic motor is ignored, the pressure of the valve port P is reduced_AI.e. the pressure P at the outlet of the gear pump 6_SThe gear pump 6 is a fixed displacement pump, the output flow Q is a fixed value, the oil inlet of the three-position five-way electro-hydraulic reversing valve 8 is in a bypass throttling mode, the flow of the outlet of the pump is discharged by a P-T valve port, the pressure of the T port can be ignored, and the pump is controlled according to a formulaCalculating the valve port flow area A at the moment, obtaining the current valve core displacement X according to a relation curve between the valve port flow area and the valve core displacement, and obtaining a current signal I corresponding to the current valve core displacement X according to a relation curve between the valve core displacement of the three-position five-way electro-hydraulic directional valve 8 and the given current of the pressure reducing valve; when the first conductive handle 1 is quickly pushed to the maximum position, the controller 2 records the current track converted by the voltage of the first conductive handle 1, the controller 2 outputs the current track operated by an operating hand, when the current signal I corresponding to the valve core displacement X calculated before is output, the current output by the controller 2 is delayed at the value by a fixed value, and when the delay time is over, the controller records the current track recorded beforeThe output is sent to the first proportional pressure reducing valve 3 and the second proportional pressure reducing valve 4, so that the flow is controlled by the valve port, namely the opening degree of the valve port can be matched with the load at the moment, and the pressure overshoot in the starting stage is reduced.

As shown in fig. 3, the current trajectory diagram in the controller 2 is shown, the curve of the EAD section is a handle ascending trajectory, the controller 2 stores the handle ascending trajectory along with the action of the conductive handle 1, point a is a current value which needs to be delayed around the current value after being calculated by the controller 2, the handle trajectory output by the controller 2 is output according to the original trajectory before the point a is reached, when the point a is reached, the fixed value delay is performed, and after the delay is finished, the previously stored handle trajectory AD section is released, that is, the handle trajectory curve of the BC section.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.