FR2677629A1 - METHOD FOR CONTROLLING THE LOAD FOR A LIFTING MACHINE AND DEVICE FOR IMPLEMENTING IT. - Google Patents

Abstract

The invention relates to a method for controlling the load for a hydraulically controlled lifting device, completely independent of the geometric configuration of the device, and comprising a stepped progression of the prohibition of movements by the introduction of two thresholds d. separate and preset alarm. Application: in the construction of lifting structures.

Description

1 - The invention relates to a method of controlling the charge for a

  hydraulically operated lifting apparatus such as a mobile crane, nacelle or other lifting structure and on its implementation devices. There are already numerous overload signaling devices which act on the hydraulic control system of the hoist in order to prohibit and / or authorize certain movements.

  arms or arrows of the craft.

  For example, the French application 2,633,268 describes a torque or torque limiting system making it possible to calculate the torque or moment exerted at any moment by a load on the turret of a machine, to compare the binary result of the preceding calculation with a load chart and then automatically act on the hydraulic control for

  slow down or prohibit any movement of the crane.

  Movements approaching hazardous areas are thus carried out at low speed. However, the device does not include the possibility of prohibiting only one or certain types of

  movement and to authorize others.

  In the French application 2,592,368, the device automatically prohibits certain movements of the arm of a hydraulic crane and authorizes others, particularly those that cause a reduction in the moment of the load, when the load reaches a predetermined threshold. charging moment is achieved by controlling the pressure

  induced in the hydraulic cylinder actuating movements.

  The main drawbacks relating to the above devices and other devices of the state of the art are that: a single parameter is controlled both for example the cylinder pressure or the inclination of the arm the device is designed specifically for a device In particular, the measures or controls carried out depend on the characteristics of the

structure specific to the craft.

  The present invention aims to overcome at least the

aforementioned drawbacks.

  A first object of the invention is to control all the

  parameters that could lead to risks.

  A second object of the invention is to design a system 2 - completely independent of the hydraulic circuit and its adjustment as well as the geometric configuration of the arms and arrows, the system being

  adaptable to the type of device on which we want to install it.

  Another object of the invention is to achieve a staged progression of the ban on movements by introducing two

  separate alarm thresholds and preset.

  Another object of the invention is to design an automatic control and alarm method but which requires the voluntary intervention of an operator to either bring the crane back to safety, or continue the aggravating movement after the

  general alerting of the system triggered by the second threshold.

  The invention will be better understood from the description

  made below with reference to the single appended figure which is a view

  schematic implementation of a device according to the invention.

  The embodiment not limited to the single figure mainly comprises: an electronic card (1) microprocessor, a plurality of sensors (2), a solenoid valve (3) cutoff, two reset contacts (4) a power supply (5). )

  a plurality of indicator lights (6).

  The sensors (2) are of any known type, for example sensors for deformation, weight, inclination and are placed in

  various points of the structure to be controlled.

  The electronic card (1) receives the information from the sensors, controls them, stores them and controls the supply of the solenoid valve (3) for cutting off the hydraulic circuit or an element of

  equivalent control for example a relay.

  The two reset contacts (4) in parallel serve to bring the machine back into safety condition by installing the elements

  electronic or reset contacts on the board.

  The power supply (5) is a 12 V or 24 V DC power supply. The set of LEDs (6) is for example 11 LEDs labeled DLI at

  D Lll whose functions are detailed below.

  The operation of the device and its adjustment are described 3 -

in detail below.

  Two alarm thresholds, detected by two sensors, are provided: a first threshold, normally "on" or "off", adjustable on the maximum load i a second threshold, also adjustable, for example and not

  limitatively, up to 250% of the first threshold.

  The pre-alarm threshold is adjustable at the desired percentage on the first threshold, normally "on" or "off" with output

independent.

  Two resets contacts are provided, the first to exit an alarm condition when the first threshold is reached, the second reset or general rehabilitation of the system to be used when the

second threshold is reached.

  In safety condition, the solenoid valve (3) is energized and

  allows the normal work of the crane.

  The electronic card causes a general alarm of the device by cutting off the hydraulic circuit when at least one or more maximum tolerated levels has reached the first threshold

alarm.

  In order to avoid alarms caused by oscillations of

  the load can be provided a short delay.

  In alarm condition, all movements are in principle

  possible after activating the first reset contact.

  Those which cause a reduction of the moment make it possible to

  again a normal operation of the crane.

  On the other hand, aggravating maneuvers of the moment cause a new general alarm when the second threshold is reached (For example: set to 110% of the first threshold), even if the reset button is

pushed.

  In alarm condition, first threshold reached, a short adjustable delay is possibly provided from the moment the reset button is pushed, in order to give the system time to evaluate.

if the moment increases or decreases.

  If the second threshold is reached, a second reset contact is provided: it is an exclusion of the system, a voluntary action by which one can bring the crane

  security condition, or to continue an aggravating movement.

  The crane returns to normal working condition and intervention logic as soon as you leave the alarm level The electronic card memorizes if and how many times the second threshold has been reached. Note also that the second reset contact can not

be kept constantly pushed.

  This is possible thanks to a logic O 1 which forbids the

system operation.

  In addition, a maximum delay is provided to bring the machine back into safety condition as soon as the second threshold has been reached and the reset button has been pushed. It is agreed that the reset button can not be pushed more than three times. without the craft being

brought back into safety.

  Moreover, the principle of adjustment of the device always foresees the setting of a minimum and a maximum, with the aid of one or

  two sensors according to the embodiment.

  The setting of the device with a single sensor is as follows: connect all the components and supply the board push the button SW 1: the LEDs DL 3 (visualization of condition of adjustment) and DL 4 (visualization of condition of adjustment sensor NO 1) light up, place the machine in the rest position and push the SW 2 button to adjust the minimum, lift the maximum load and place it in the most critical condition where you want the device to work, push the SW 3 button for storing the alarm condition, push the SWI button to confirm, and exit the set condition; this output is possible only after setting the maximum. Once the SWI button has been entered into the general condition, the minimum (SW 2) or maximum (SW 3) debug operations can be repeated or corrected. Only the last values will be stored and confirmed. with the exit of the 4 -

  general condition of adjustment by the SWI button.

  In a two-sensor device, the setting is as follows: connect all the components and power the board: the GREEN LED DL 9 lights up, push SWI, DL 3 and DL 4 light up, put the machine in condition of rest and push SW 2 for setting the minimum sensor NO 1, push S Wl; the LED DL 5 comes on (display of sensor setting condition N O 2), push SW 2 to set the minimum sensor N O 2, push S Wl; the LED DL 4 comes on, lift the maximum load and place it in the most critical condition where you want the intervention of the sensor NO 1, push SW 3 to memorize the alarm condition of the sensor n O 1, push SWI; the LED DL 5 lights up to inform that we are now acting on the NO 2 sensor, put the maximum load in the most critical condition where we want the intervention of the sensor 2, push SW 3 for the setting in memory of sensor 2 alarm condition,

  push SW 1 to confirm and exit the setting condition.

  In addition, it is necessary to adjust internal parameters by the mini computer (PSION) of the electronic card the memorization of the alarm the storage of the pre-alarm the polarity of the output signal of the pre-alarm the delay of the alarm (of the order of tenths of seconds) the latency time of the device from the reset maneuver to exit the alarm condition first threshold the percentage of the pre-alarm sensors 1 and 2 the percentage of the second threshold, sensors 1 and 2 the number of use of the reset second threshold the parameter confirmation the elimination of all parameters possibly set -6Each command with the "PSION" must be followed by the

EXE command.

  The DC power supply (5) is protected against a polarity inversion by a fuse and the temporary overloads do not damage the circuit. At each switching of the electronic card, a self-test

  system functions is planned.

  Anomaly check is provided on the map

  electronics, sensors and battery pack.

  Any anomalies are visualized by all LEDs. Three of them tell us about the state of charge DL 9: GREEN, live card DL 7: YELLOW, pre-alarm DL 8: RED, alarm Six of them tell us the controls of the functions D Ll: the maximum value of the sensor (1) has been reached (not stored) DL 2: the maximum value of the sensor (2) has been reached (not stored) DL 3: two functions: each time the system is switched on, DL 3 ' turn on for one second to indicate a self-test for the functions indicated by the LEDS DL 4-DL 5-DL 6-DL 10-D Lll; if everything is correct, it goes out; if not

  it remains lit with the LED corresponding to the anomaly.

  it remains lit to indicate that you are in the tuning phase.

  DL 4: two functions: flashing light indicates sensor fault NO 1 continuous light signals sensor adjustment condition NO 1 DL 5: two functions similar to LED DL 4, for sensor no. 2 DL 6: overload, fuse to be changed, DL 10: anomaly of the electronic card D Lll: insufficient battery charge In pre-alarm and alarm state the card can directly supply a control element to 1.5 A maximum (solenoid valve,

relay).

  The output voltage is identical to the voltage 7 - supply. The originality of the operating methods according to the invention resides in particular in the fact that it is possible to modify the parameters: delay on alarm, on pre-alarm according to the particularities of each machine We also note that there is always a

  threshold beyond which one can go only by voluntary action.

  For example, it is possible to have two independent levels of adjustment with a single sensor, using the pre-alarm output as the first alarm level, which, together with the supermax threshold, gives us three levels of alarm so

three possible cuts.

  In addition, it is possible to program the change of

  card settings directly with the minicomputer.

8 2677629

Claims (8)

  A method for controlling the load for a lifting gear with a hydraulic control circuit of a lifting structure, characterized in that it comprises two distinct and preset alarm thresholds, on the other hand there is a threshold beyond which we can go only by voluntary action and secondly in that it causes a general alarm by cutting the hydraulic circuit when   at least one of the maximum tolerated levels has reached the first threshold.   2 Method according to the preceding claim, characterized in that the first threshold is adjustable on the maximum load and the second   threshold is adjustable to the level of the desired percentage on the first threshold.   3. Process according to the preceding claim, characterized in that   that the second threshold is adjustable up to 250% of the first threshold.   4 Method according to one of the preceding claims,   characterized in that, after activation of a first reset contact,   all the movements of the structure are possible.   Method according to one of the preceding claims,   characterized in that in alarm condition, first threshold reached, a short adjustable delay is provided to bring the structure back into security condition.   Method according to one of the preceding claims,   characterized in that the adjustment parameters are modifiable in   function of the peculiarities of the structure.   Method according to one of the preceding claims,   characterized in that the reset button can not be activated more than three   times without bringing the structure back to safety.   Method according to one of the preceding claims   characterized in that the setting parameters are modifiable by   actions on at least one reset button.   Process according to one of Claims 1 to 7, characterized in   the setting parameters are programmable.   Device for carrying out the method of claim 1 comprising a microprocessor electronic card a plurality of sensors a shut-off solenoid valve or other equivalent control element a DC power supply a plurality of anomaly indicator lights, characterized in that it comprises two reset contacts (4) in parallel which serve to bring the machine back into safety condition, in that it also comprises a fuse protecting the supply of a polarity inversion and in that the card supplies power directly the control element. Apparatus for carrying out the method of claim 1 comprising: a microprocessor-based electronic board a plurality of sensors a shut-off solenoid valve or other equivalent control element a DC power supply a plurality of anomaly indicator lights characterized in that it comprises a single reset contact (4), a fuse protecting the supply of a polarity inversion, the card   directly feeding the control element. 9 -