Electrically-driven crane load capacity limitation method

FIELD: transportation.

SUBSTANCE: in compliance with the proposed method, with electric key set up, loads are uplifted in turn, their weights making m0, ..., mi-1, mi where i=2, 3, ..., and the motor shaft respective rpm making n0, ..., ni-1, ni being recorded by means of the accelerometer arranged on the base plate or the crane motor bed are memorised. The accelerometer output signal is subjected to spectral analysis with the frequency whereat the motor bed vibration fundamental amplitude is determined corresponding to the motor shaft rpm. Now, proceeding from the data obtained, the dependence of the motor rpm upon the uplifted load n=f(m) is derived to be memorised along with the known tolerable uplifted load weight value. Now, uplifted the load, the motor shaft rpm value is continuously measured by accelerometer to define, proceeding from n=f(m), the load weight. If this weight exceeds the tolerable value, audio and visual warning signals are output and the crane if cut off.

EFFECT: higher reliability of the crane capacity limiter.

6 dwg

 

The invention relates to safety devices for cranes and is intended for overload protection of electric lifting mechanism of the crane.

There is a method of limiting the load on the boom of the crane (RF patent for the invention №2011632, IPC 5 VS 23/90, publ. 04.30.1994). A method of restricting the carrying capacity based on receiving the analog parameters of the crane, load independent, which is converted into digital form. This information, as well as discrete parameters and signals depending on the mode of operation of the crane, and pre-stored information is processed, and the work is coordinated from the unit of time. Processed information in the form of a loading crane and other values displayed visually, depending on the magnitude of the load warning alarm, and in case of exceeding the permissible load values generated command "Overload". In the case of multiple repeat commands "Overload" is the command "Off valve". The amount of time during which continuously should be developed team "Overload" in order to develop the command "Off valve", is determined by the dynamics of the crane.

A known method of controlling the lifting mechanisms with fixation of their performance and device for its implementation (PA is UNT of the Russian Federation for invention №2116240, IPC 6 VS 23/90, publ. 27.07.1998). The method of controlling the lifting mechanisms with the fixation of their performance on pressure, geometry of the crane and its mode of operation, based on the measurement signals proportional to these characteristics, primary processing of these signals are converted into digital form, in accordance with pre-stored signals, determining the processing order, coordinate the processing of the generated pulse sequence in real-time, their display and in case they exceed the allowable values, the formation of control signals and applying the latter to the control device, when this set time interval, and really having a place exceeded, signals proportional to the characteristics of lifting mechanisms, valid values trial in the case of the last primary processing signal exceeding the preset threshold level in the specified time interval, when this record in long-term non-volatile memory for storing unchanged last primary processing signals proportional to the above mentioned parameters to account for the life of the crane under load, the time of appearance of these signals exceeding the preset threshold level, and the generated control with gnali read if necessary.

The disadvantages of the known technical solutions is the use of hydraulic units building crane and the use of pressure sensors as sensors that produce a signal proportional to the load, so it is impossible to use such means to limit capacity in electric cranes.

A known method of limiting crane capacity (RF patent for useful model №32480, IPC 7 VS 23/88, publ. 20.09.2003), which measure the mass of the goods using the load item, equipped with a force sensor, and compares it with the maximum permissible value and when it is exceeded, turn off the faucet.

The disadvantage of the proposed technical solution is to use the built-in steel load sensor, which is a method of direct measurement of mechanical stresses arising from the action moved. Using the proposed method of measuring the mass of the cargo requires changes in the metal structure of the crane, which increases the cost of equipment.

A known method of limiting capacity electric crane (RF patent for useful model №41460, IPC 7 VS 23/90, publ. 27.10.2004), selected as a prototype, which consists in the fact that after the installation of electronic key record in digital saponin the store unit maximum allowable current value, phase voltage and weight lifted cargo, and also remove the dependence of the frequency of rotation of the motor shaft from the weight of the lifted load, which in turn raise a few loads with mass m0, ..., mi-1, miand remember the corresponding values of the rotation speed n0, ..., ni-1nithe motor shaft and saves the resulting dependence in the digital storage unit. Directly electrical tap the signals from the sensor current, phase voltage and frequency of rotation of the motor shaft is continuously output in the digital computing unit. This information, together with information extracted from the digital storage unit, process parameters, reflecting the work of the electric valve, and transmit block visual and audible indication, and in case of exceeding the allowed values of the mass lifted cargo and controlled parameters of the mains supply produce to shut off mechanism of a lift, which goes to the Executive block.

The disadvantage of limiting the capacity is its low reliability. The measurement of the frequency of rotation of the motor shaft is produced by using a Hall sensor mounted on the motor housing, and a magnet mounted on the motor shaft. However, node: Hall sensor - magnet is exposed to mehanicheskaya destruction in the process of exploitation and degradation in the aging process.

The objective of the invention is to increase the reliability of the method of restricting the capacity electric crane.

The problem is solved due to the fact that in the method of limiting capacity electric crane as well as in the prototype after the installation of electronic key alternately raise the cargo mass m0, ..., mi-1, miwhere i=2, 3, ... and remember the corresponding values of the rotation speed n0, ..., ni-1nithe motor shaft. Further, according to the data obtained to build the dependence of the frequency of rotation of the motor shaft from the weight of lifted cargo n=f(m), trying to remember together with the known maximum permissible weight of lifted load. Then, raising operating load, continuously measure the frequency of rotation of the motor shaft, using which the dependence n=f(m) determine the mass of the working load, and if this mass exceeded the maximum permissible value, an audible and visual signal and turn off the faucet.

According to the claimed method to determine the values of frequencies of rotation of the motor shaft in all the above cases the use of the accelerometer, or installed on the base plate, or on the frame of the crane motor, and the output signal from the accelerometer is subjected to spectral analysis (Fourier transform), and the frequency to the second determined value of the amplitude of the 1st harmonic vibrations of the frame of the engine, corresponds to the frequency of rotation of the motor shaft.

Installation of the accelerometer on the stationary part of the electric crane or support plate or bed of the crane motor to determine the frequency of rotation of the motor shaft on the fixed part of the crane motor unlike the prototype, where these measurements are made on a rotating shaft of the motor. Thus, it improves the reliability of operation of the method of restricting the capacity electric crane.

Figure 1 shows the functional diagram of the limiter-duty electric crane.

Figure 2 presents the timing diagram of the signal nTgTacho (a) and vibrogym signal Anaccelerometer (b) when operating crane with a mass of m=0 so

3 shows timing diagrams of the signal nTgTacho (a) and vibrogym signal Anaccelerometer (b) when operating crane with a mass of m=20 so

Figure 4 presents the dependence of the rotational speed n of the motor shaft from the mass m is lifted cargo.

The proposed method is implemented using the load limiting device shown in figure 1, where the digital computing unit 1 is connected with the corresponding outputs of the input block information 2 and the accelerometer 3 installed in or on the base plate, or on the frame of the crane motor. Qi is the global computing unit 1 is connected also with digital storage unit 4, with the Executive block 5, block visual and audible indication 6, a timer 7, and e 8 key.

As a digital computing unit 1 can be selected single-Board microcontroller type ATC with a clock frequency of 4 MHz. Block input information 2 is a set of control buttons to enter information and set the operation mode of the digital computing unit 1. Accelerometer 3 can be performed on the chip type ADXL, and digital storage unit 4 can be represented in the form of FLASH memory. Executive unit 5 made in the form of three-phase power relay control via composite transistor from the digital computing unit 1. Block visual and audible indication 6 represents the output register with indication of the decimal code on the seven-segment indicator, audible indication is carried out by the system. Timer 7 can be made in the form of the generator of the pulse sequence. Electronic key 8 is a persistent storage device that contains code access permissions to reprogramming digital computing unit 1, is made removable and is installed in the external connector digital computing unit 1.

Before you begin installed on electric crane load limiting device introduced in memory of cifrovoj the storage unit 4 the dependence of the frequency of rotation of the motor shaft from the weight of lifted cargo n=f(m). To build dependence n=f(m) with a minimum accuracy required to obtain two operating points: when operating crane with an empty hook suspension and cargo weight, close to the nominal. This was hooked up to a digital computing unit 1 electronic key 8, then the digital computing unit 1 is moved into the program "training". Then he lifted the empty hook suspension mass m0=0 t and determine the corresponding value of the rotation frequency n0motor shaft after spectral analysis in digital computing unit 1, the signal taken from the output of the accelerometer 3. Figure 2 (a) presents the obtained dependence of the values of the amplitudes Andnharmonic vibrations of the frame of the engine (normalized in the range 0...1) from the oscillation frequency of the motor f (Hz). The peak amplitude of the vibrations of the engine of Anfrom figure 2 (a) is 16 Hz, which corresponds to the rotational speed of the motor shaft n0=16 R/C. This value was confirmed by the testimony of the Tacho-generator, which is installed on the motor shaft at the time of the experiment. The dependence of the frequency of rotation of the motor shaft (signal Tacho) nTgfrom time t represented in figure 2 (b), which implies that nTg=16 R/C.

Then he lifted the load close to the rated capacity electric crane (m1=20 t), and determine the corresponding value is the frequency of rotation n 1the motor shaft. The output signal from the accelerometer 3 after spectral analysis in digital computing unit 1 is presented in figure 3 (a), which implies that the peak amplitude Anfluctuations of the engine is 12 Hz, which corresponds to the rotational speed of the motor shaft n1=12 R/C. This is also confirmed by the testimony of the Tacho signal is shown in figure 3 b) and is nTg=12 R/C.

Further, according to the obtained data, we constructed the dependence of the rotation frequency of the motor shaft from the weight of lifted cargo n=f(m), which is presented in figure 4. Then, in the digital storage unit 4 has retained constructed the dependence n=f(m) and the value of the maximum permissible load mass (mCR=22 t), which is introduced through the input block information 2.

Directly electric crane with a load limiting device in the digital computing unit 1 is continuous determination of the frequency of rotation of the motor shaft based on the signal produced by the accelerometer 3. The frequency of rotation of the motor shaft defining the weight lifted cargo on the basis of dependence n=f(m) (figure 4) and record the value of this mass with the help of block visual and audible indication 6. In case of exceeding the permissible weight of lifted load shaft speed of the engine will drop to predelnoj the values of n CR=11,6 rpm that will meet the limit value of the weight lifted cargo mCR=22 tons, and digital computing unit 1 generates a command to shut off mechanism of a lift, which goes to the Executive block 5, block 6 audible and visual signal, and the values of date and time received from the timer 7, recorded in the digital storage unit 4.

A method of restricting the capacity electric crane, which consists in the fact that after the installation of electronic key alternately raise the cargo mass m0, ..., mi-1, miwhere i=2, 3, ..., and remember the corresponding values of the rotation speed n0, ..., ni-1nimotor shaft, then the data and build the dependence of the frequency of rotation of the motor shaft from the weight of lifted cargo n=f(m), trying to remember together with the well-known maximum weight lifted cargo, and then, raising operating load, continuously measure the frequency of rotation of the motor shaft, using which the dependence n=f(m) determine the mass of the working load, and if this mass exceeded the maximum permissible value, an audible and visual signal and turn off the faucet, characterized in that for determining the values of frequency of rotation of the motor shaft in all of the above cases sportsouth accelerometer, installed or on the base plate or on the frame of the crane motor, and the output signal from the accelerometer is subjected to spectral analysis, and the frequency of which is determined by the value of the amplitude of the 1st harmonic vibrations of the frame of the engine corresponds to the frequency of rotation of the motor shaft.



 

Same patents:

FIELD: transportation.

SUBSTANCE: device contains the boom equipment load and spatial position pickups, the output device, the graphic display with the graphic memory unit and the processor connected with the said pickups, graphic display and output device connected to crane actuators. The processor generates a schematic image of the crane and its operating area on the screen of the graphic display. In the first version of the device, the processor produces a dynamic image on the display of the crane operating area proceeding from the necessity to prevent the crane overload and its collisions with obstacles. In other versions of the device, the operating area is generated on the display by the signals received from outside moving or stationary objects using the crane operating area locator signals, using boom equipment extreme coordinates in motion and/or signals generated by operator acting on the sensor display screen capable to output 3D images.

EFFECT: higher safety of the load-lifting crane operation.

20 cl, 2 dwg

FIELD: mechanical engineering; tower cranes.

SUBSTANCE: method includes periodical continuous polling during which signals are obtained, recorded and memorized which correspond to values of load characteristic of crane, crane geometry and operation conditions, obtained signals are compared with values of characteristics introduced into crane control system before its operation, and after comparing of signals received at polling with tolerable values of characteristics, if they exceed tolerable characteristics, commands of crane operator are cancelled. Introduced additionally into crane control system are parameters of crane operation conditions, speed of wind, ambient temperature and crane condition parameters, load, vibration, temperature of crane drive mechanism lubricants, and voltage in electrical devices. Maximum tolerable values of said parameters are introduced into control system to limit operation of crane drives at which operation of crane should be stopped or can be executed at introduction of definite limitations into operation of crane drive as to speed, accelerations, combined or successive travel motions of drives, obtained signals concerning operation and state of crane are compared with tolerable values, and possibility and conditions of execution of operator's commands are determined, command is left without changes or definite limitations are applied to operation of crane by introducing corresponding corrections to operator's command or execution of command is prohibited according to preset program.

EFFECT: improved safety of operation of tower crane.

1 dwg

FIELD: hoisting and transportation machinery, particularly to control and protect hoisting machines against overload.

SUBSTANCE: system comprises the first control means group installed on support structure or on equipment parts not to be separated from structure. The first control means group includes digital data processing unit 2 having output connected to executive and signaling device 4, 5 units, the first data input-output unit 3 linked to digital data processing unit with two-directional data exchange channel, crane 6 parameter sensors and power supply unit 1. Power supply unit 1 has one clamp connected to load-lifting machine body and another clamp secured to power supply system bus. The second control means group is supported by movable structure or equipment to be demounted and includes crane parameter sensors 10. The first and the second control means groups are linked one to another through two-directional radioline. The first control means group is provided with the first receiving/transmitting radio station, independent power source 15 and switchboard 16.

EFFECT: increased safety system reliability, simplified assemblage and installation thereof on load-lifting machine.

1 dwg

FIELD: mechanical engineering; lifting and transportation equipment.

SUBSTANCE: invention relates to protection devices for load-lifting machines used in construction engineering. According to proposed method, by successive polling of signals of first complex of pickups by data processing base unit and by transmitting of commands through drum with current carrying ring to controller of extendable part for connection of technical devices and receiving information from second complex of pickups, drives of load-lifting machine mechanisms are switched off when actual characteristics exceed tolerable values. Provision is made for connecting current-carrying ring of drum through marker light switch of one terminal of supply source whose second terminal is connected with metal structure of load-lifting machine.

EFFECT: enlarged functional capabilities of load-lifting machine, provision of convenient and reliable transmission of commands for selective connection of devices arranged on extendable part and reception of information from pickups arranged on said part.

7 cl, 2 dwg

FIELD: mechanical engineering.

SUBSTANCE: according to proposed method of supporting crane operator to provide safe operation of load-lifting crane, operating parameters of crane are measured and processed and information is shown on display for necessity of taking measures to eliminate emergency situation. Data base is created additionally concerning combination of operating parameters of crane at different loads and spatial positions of boom or load-gripping member giving rise to danger at crane operation and said data base is kept on crane. Forecasting of appearance of emergency situation is provided by means of computer with use of data base and, when necessary, by means of mathematical model of crane, and additional measures taken by crane operator to prevent trouble are shown on display.

EFFECT: improved safety of crane operation and operating conditions for crane operator.

22 cl, 1 dwg

FIELD: mechanical engineering; tower cranes.

SUBSTANCE: invention relates to materials handling facilities and it can be used particular to adjust overload safeguards of tower cranes. Suspended dynamometer with direct of remote control is used when accomplishing the method and implementing the device. Dynamometer is installed between load hook and point of fastening, and load moment is controlled after setting lifting mechanism in adjustment position. For this purpose preset value limiting load torque of electric motor which control operation in direction of lifting is supplied by sending order to said motor and reading values of stretching forces put out by suspended dynamometer.

EFFECT: reduced duration and cost of adjustment of overload safeguards.

11 cl, 2 dwg

FIELD: mechanical engineering; load-lifting machinery; safeguards.

SUBSTANCE: strain-gauge transducers are installed on outriggers. Analog-digital converter is connected to outputs of strain-gauge transducers. On-board microprocessor is installed for processing data array formed by analog digital converter, control of hydraulic cylinders of support circuit by hydraulic distributor and putting out required information to operator's display. Moreover, on-board microprocessor is furnished with relay module, and mathematical model of load-lifting machine made with possibility of changing, depending on type of load-lifting machine used, is entered into its memory. Additionally hydraulic distributor is connected in parallel with said hydraulic distributor coupled through system of controllers with relay module of on-board microprocessor and designed for re-distribution of liquid from piston spaces of hydraulic cylinders in case of danger of turnover of load-lifting machine.

EFFECT: increased capacity of machine, improved safety at load-handling operations.

2 cl, 3 dwg

FIELD: materials handling facilities.

SUBSTANCE: group of inventions is designed for protection of boom cranes at operation in confined areas and near electric power lines. According to first methods, sensor in form of electric antenna is mounted on boom to detect voltage, amplify it, filter and convert the voltage into emergency signal or crane motion blocking signal, additional vibratory displacements of sensor of sensor mounted on boom are provided. Reception of acoustic signal created by vibrating sensor and reflected from objects surrounding the crane can be provided and amplitude and/or Doppler frequency shift can be revealed and, basing on their values, distance to objects surrounding the crane or speed of their approach to crane can be determined, and at decrease of distance or increase of speed above tolerable values, emergency signal or crane blocking signal can be formed additionally. Forming of ultrasonic signal can be done not by mechanical vibrations of antenna, but by means of separate acoustic converter. Additional forming of modulation signals and acting by this signal onto amplitude or vibration frequency of sensor and determination of distance to objects surrounding the crane can be provided by measuring delay of received signal relative to modulation signal. According to second method, movement of crane boom and sensor mounted on boom are determined additionally and, depending on parameters of movement, sensor voltage amplification factor or indicated threshold level are determined. Direction of movement can be revealed additionally and, depending on said direction, sensor output voltage amplification factor or said threshold level can be changed. Revealing of boom movement can be done not by revealing the direction, but by revealing the speed, and sensor output voltage amplification factor can be increased or set threshold level can be reduced proportionally to said speed. Protection of crane from dangerous approach of boom to electric power line in traveling is provided owing to the fact that at revealing of boom movement speed, translation of crane is additionally taken into account. Direction of location of obstacle is revealed additionally and, if said obstacle approaches the crane with boom motionless, boom drive of crane is switched on to move in opposite direction to automatically prevent collision of boom with said obstacle. Device for implementing proposed method contains sensor mounted on boom and electronic unit whose input is connected to sensor and output is connected with input of emergency signaling or crane movement blocking device, and electromechanical converter connected to electronic unit. Sensor is fastened on electromechanical converter, and electronic unit is made for generating excitation signal of electromechanical converter. Acoustic signals can be received by means of additional acoustic converters connected to additional outputs of electronic unit.

EFFECT: provision of reliable protection of crane from dangerous approach to ac and dc electric power lines.

15 cl, 1 dwg

FIELD: equipment for controlling and protection of load-lifting mechanisms from overloads and damage.

SUBSTANCE: method involves controlling load-lifting mechanism by measuring signals proportional to loading and/or geometry thereof; processing signals converted to digital form in accordance with preliminarily stored signals determining order of processing in real time and indicating resulting processing data; in case allowable values of signals are surpassed, generating control signals and delivering the latter to actuating device; providing additional processing of signals characterizing results of measurement of loading and/or geometry of load-lifting mechanism by filtering thereof, including leveling down of vibrations in dynamic modes of operation of load-lifting mechanism, or changing coefficients of amplification of these signals depending on preliminarily stored characteristics of measuring devices or values of said signals; processing resultant signals in digital form.

EFFECT: increased efficiency and enhanced reliability in operation of load-lifting mechanism and interchangeability of loading sensor and crane geometry.

2 cl, 1 dwg

FIELD: mechanical engineering; materials handling equipment.

SUBSTANCE: in proposed case functions of overturning moment and nominal forces of supports are synthesized from signals of support pickups. Overturning moment is reduced to one "window" whose upper limit corresponds to maximum of overturning moment, and operation of protection and is defined by constant value of restoring moment which depends on size of support outline and mass of counterweight. Created no-program device is adaptive to overturning moment and distribution of forces in supports and contributes to correct mounting of crane on supports from traveling position. Horizontal arrangement of platform and nominal distribution of forces of supports are maintained. Mounting of crane on supports is provided even is deviation of actual forces in supports from nominal values is revealed.

EFFECT: provision of protection of higher reliability and accuracy, improved service and dynamic characteristics of crane.

6 cl, 4 dwg

FIELD: hoisting-and-transporting mechanical engineering.

SUBSTANCE: invention can used in the crane control and safety systems. Method consists in transfer of control signals from remote control board (RCB) located outside the crane using a two-way line of wireless communication, measuring the working parameters, converting measured sizes into digital signals, defining safe loads and limiting positions of the crane structural components and switching off its mechanisms on reaching limiting values, recording the crane operating and data signals and time of their arrival into long-term nonvolatile memory to be read out in case of need, and also their remote transfer to the dispatcher control located outside the crane. In addition, RCB outputs the instructions to transfer the crane data and control signals to be written down into RCB nonvolatile memory to be read out in case of need by transmitting the signals to the dispatcher control station, registration and storage of data on the crane operation. Here, note that two-way wireless communication lines are used to this end.

EFFECT: higher reliability of control and registration of crane working parameters.

1 dwg

FIELD: transportation.

SUBSTANCE: adjustment consists in regulation of signals in channels of measurement of boom load, overhang or inclination angles by adding and/or multiplying these signals with the signals corresponding to the adjusting parameters the values of which are preliminary defined and stored in power-independent memory of the safety device. Regulation is made without of reference cargoes proceeding from the conditions of independence of the results of measurement of the lifted and moved cargoes upon the boom length and inclination angle. Values of adjusting parameters are defined, allowing for the boom deflection, as the constants or functions of the boom overhand, length and inclination angle by commands of the operator/crane operator or automatically. The principle of definition of adjusting parameters is based, in particular, on their calculation as unknown factors in a set of the equations derived using the crane mathematical model. The said device contains transducers of the load-lifting crane operating parameters with digital or analog outputs and the digital computing device with power-independent memory.

EFFECT: opportunity of checking the accuracy of the safety device operation without check cargoes is ensured and efficiency of protection of the load-lifting crane is increased.

16 cl, 1 dwg

FIELD: construction.

SUBSTANCE: series of inventions refers to the sphere of tower crane operation security engineering. The method in question presupposes exchange of information on the cranes locations, movements and equipment loads between the control and protection devices of all the "n" jointly operating tower cranes. Additional features: identification of the position of each crane and/or its equipment against the construction site plan, conventional graphical visualisation of the position within the construction site territory of a specified crane and/or its equipment (as well as that of the "neighbouring" cranes and equipment related to them) on the crane display. When the crane operator initiates relocation of equipment related to crane Ki the following is carried out: the intended equipment motion path tracing, display graphical visualisation of the intended motion path(s) of the equipment related both to crane Ki and the "neighbouring" crane(s) whose equipment is currently in motion (by means of exchange of information between the control and protection devices), estimation of the minimum distance between the above paths, graphical visualisation of the point of intersection on the crane Ki display and generation of a signal disabling operation of this crane equipment and light and sound alarm signals in case the paths as having been traced happen to intersect. In order to enable further motion of the crane Ki equipment there is an additional line to be plotted by the crane operator which is intended to restrict motion of the crane equipment (the line becomes graphically visualised on the crane Ki, screen); in case the limiting line has been plotted erroneously operation of the crane Ki equipment and mechanisms is automatically disabled when at the paths intersection point.

EFFECT: improving the hoisting cranes operation standard of safety.

4 cl, 3 dwg

FIELD: mechanical engineering.

SUBSTANCE: invention relates to load-lifting and transportation equipment and it can be used in protection systems of load-lifting cranes. According to proposed method, tolerable loads are determined and memorized in form of function of spatial position of boom, measuring current value of load in process of operation of crane, comparing it with tolerable load and generating warning signal or signal to crane mechanisms aimed at limiting or preventing overload. In process of lifting and/or shifting of load, change of linear or angular position of crane part is revealed additionally whose change is not allowed in current stage of load lifting and/or shifting process. Depending on value of said change of position, additionally warning information signals or crane mechanism control signals are formed aimed either to prevent further increase in said change or to return said part of crane, for instance, boom, into initial position. Protection of crane from overload is implemented with due account both of absolute value and change of value of angle of tilting of crane component part from horizontal or vertical position in process of lifting and/or shifting of load.

EFFECT: improved safety of crane in operation.

21 cl, 1 dwg

FIELD: mechanical engineering; lifting and transportation machinery.

SUBSTANCE: invention can be used in automated protection and control systems of load-lifting cranes. Load-lifting machines drive is controlled by operator acting onto control member, transmission of shifting of said member to control member of drive made to shift any mechanism of load-lifting machine depending on movement of control member, and preliminary determination of tolerable value of at least one parameter characterizing load and/or spatial position of boom or load-gripping member of load-lifting machine, keeping the parameter value in memory, measuring said parameter by direct or indirect method in process of operating of load-lifting machine, comparing measured value with tolerable value and subsequently shaping drive control signal. Control signal is used to interlock shifting of drive control member and if, necessary, to reset member in neutral position. Interlocking of drive control member is done by mechanical blocking of transmission of control member shifting to drive control member or mechanical interlocking of displacement of said member.

EFFECT: increased reliability.

6 cl, 3 dwg

FIELD: mechanical engineering; tower cranes.

SUBSTANCE: method includes periodical continuous polling during which signals are obtained, recorded and memorized which correspond to values of load characteristic of crane, crane geometry and operation conditions, obtained signals are compared with values of characteristics introduced into crane control system before its operation, and after comparing of signals received at polling with tolerable values of characteristics, if they exceed tolerable characteristics, commands of crane operator are cancelled. Introduced additionally into crane control system are parameters of crane operation conditions, speed of wind, ambient temperature and crane condition parameters, load, vibration, temperature of crane drive mechanism lubricants, and voltage in electrical devices. Maximum tolerable values of said parameters are introduced into control system to limit operation of crane drives at which operation of crane should be stopped or can be executed at introduction of definite limitations into operation of crane drive as to speed, accelerations, combined or successive travel motions of drives, obtained signals concerning operation and state of crane are compared with tolerable values, and possibility and conditions of execution of operator's commands are determined, command is left without changes or definite limitations are applied to operation of crane by introducing corresponding corrections to operator's command or execution of command is prohibited according to preset program.

EFFECT: improved safety of operation of tower crane.

1 dwg

FIELD: mechanical engineering; lifting and transportation machine building.

SUBSTANCE: invention can be used in control and protection system of load-lifting cranes. Proposed system contains load pickups 1, boom tilting angle pickups 5, parameters indicator 6 and series-connected tolerable load setting unit 8, comparator 9 and actuating unit 10 whose output is connected to first input of parameters recorder 11, unit to record designed values of parameters 12, correction unit 3, load weight check unit 2, scaling unit 4, variable coefficients unit 14, change-over switch 15, boom deflection recording unit 13 and boom reach calculating unit 7.

EFFECT: improved safety of crane owing to increased accuracy of control of its parameters.

2 cl, 2 dwg

FIELD: lifting and transportation mechanical engineering, namely system for ensuring safety of operation of lifting equipment; possible use for preventing dangerous approach of jib type cranes with telescopic crane arms to power lines.

SUBSTANCE: device for detection of electric field of power line contains an antenna and antenna amplifier, where at least a part of antenna is made in form of flat capacitor mounted on rotary device of crane, and current-conductive plates of flat capacitor are connected to input of antenna amplifier. Positioning of antenna in form of flat capacitor not on the head of crane arm, but on rotary device, ensures safety of crane operation during installation of fly jib, and also results in increased comfort of operation, particularly, low length of communication line and exclusion of drum for winding cable, removing causes for cable tearing under conditions of real applications.

EFFECT: increased efficiency.

2 cl, 4 dwg

FIELD: hoisting and transportation machinery, particularly to control and protect hoisting machines against overload.

SUBSTANCE: system comprises the first control means group installed on support structure or on equipment parts not to be separated from structure. The first control means group includes digital data processing unit 2 having output connected to executive and signaling device 4, 5 units, the first data input-output unit 3 linked to digital data processing unit with two-directional data exchange channel, crane 6 parameter sensors and power supply unit 1. Power supply unit 1 has one clamp connected to load-lifting machine body and another clamp secured to power supply system bus. The second control means group is supported by movable structure or equipment to be demounted and includes crane parameter sensors 10. The first and the second control means groups are linked one to another through two-directional radioline. The first control means group is provided with the first receiving/transmitting radio station, independent power source 15 and switchboard 16.

EFFECT: increased safety system reliability, simplified assemblage and installation thereof on load-lifting machine.

1 dwg

FIELD: mechanical engineering.

SUBSTANCE: invention relates to safety and control systems of load lifting cranes. Proposed method of supply of measuring and control component part of safety and control system arranged on boom or tackle block of load-lifting crane comes to use of self-contained supply source with automatic charging the source from generator - converter of mechanical energy of moving load or boom wire rope of load-lifting crane or block directing or supporting the wire, rope, into electric energy. According to invention, said component part of safety and control system of crane provides measuring of at least one operating parameter and control of loads, particularly, marker light and/or headlight. To charge self-contained supply source, in additional of wire rope motion energy, use can be made of energy of external mechanical actions, solar energy or heat energy of surrounding medium. Transmission of data between component parts of system can be provided by wireless data exchange channel.

EFFECT: facilitated maintenance, increased reliability, provision of serviceability of safety and control system of crane.

16 cl, 2 dwg

FIELD: mechanical engineering; material handling machinery.

SUBSTANCE: proposed method includes measuring or crane loads, traveling of crane with load and time of operation of crane mechanisms, recording of data and comparing them with normal characteristics of crane. In process o measurement, crane operating cycle is found. Beginning of cycle is determined by switching on any other mechanism after switching on load lifting mechanism at G>Gnl and L>Lnl where G is actual load from load on crane hook, Gnl is load at no load on crane hook, ZL is displacement of center of gravity of hook casing relative to center of gravity of load, Lnl is maximum tolerable displacement of center of gravity of hook casing relative to center of gravity of load. End of cycle is found by beginning of following cycle after execution of load lifting in case of no load on crane hook at G>Gnl and operation of any mechanism of horizontal displacement of load at L>Lnl. Simultaneously with determination of beginning and end of cycle, load G is measured at beginning of load lifting in period from moment of exceeding of load Gnl to moment of switching on any other load horizontal displacement mechanism. Current mean value of load is calculated within time interval Δt. Maximum value of current mean load is determined also within said period. Basing on maximum value of current mean load, mass of load is determined, and crane cycle with obtained mass of load is recorded. Then cycles with corresponding load masses are summed up. According to obtained data crane is classified to group of class, data obtained in each group of class are compared with normal characteristics of crane according to specifications and , basing of results on comparing, crane is placed in operation, or crane operator is warned or operation of crane is prohibited. Proposed device contains sensors of load and horizontal displacements, processing unit and comparing unit. Device includes also crane operation cycle revealing unit, cycle recording unit, load mass metering unit, AND and OR units and crane state evaluation unit.

EFFECT: provision of reliable data on conditions of crane, improved safety.

3 cl, 1 dwg

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