FI83205B - Device for protecting load lifting mechanisms from overloading and turning - Google Patents

Description

1 83205

Device for protecting lifting gear from overload and tipping

The invention relates to lifting and transfer machines and, more particularly, to devices for protecting lifting machines from overload and tipping, which device comprises electrically connected to each other a lifting machine overload determining unit, a lifting machine stopping unit and a lifting machine actual stability control unit.

The present invention can be used to protect hydraulic cranes with a swivel boom in which the wheels operate pneumatically from overload and torsion.

A device for protecting lifting devices from overload and torsion is known from the prior art (SU Patent Publication No. 1,101,402), which comprises a lifting machine overload determining unit and a lifting machine stopping unit which are electrically connected to each other.

However, the known device is adjusted according to the calculated contour of the supporting structure of the hoisting machine, e.g. a crane (preferably in terms of its configuration) and does not react in any way to unfavorable changes in this contour, for example when the soil subsides under one of its outriggers and the (calculated) (true) triangular, which reduces the accuracy of the device, which in turn reduces the reliability of the lifting gear safety system and may lead to a malfunction.

In addition, in the known device, the hoist overload determining unit programs the load characteristic corresponding to the minimum (calculated outline of the supporting structure) load capacity (allowing wind effect, bridge slope, individual unit strength conditions 2 83205, etc.), which in most cases results in hoist capacity.

U.S. Pat. No. 3,638,211 describes a crane safety device that protects a crane from a predetermined higher load estimated from the position of the boom (boom length and angle of inclination). The disadvantage of such a safety arrangement is its poor adaptability to various crane operating conditions, such as the effect of the soil, the effect of the wind, etc.

The main object of the present invention is to provide a device for protection against hoisting and overload and torsion, with additional units which enable the accuracy of the device to be increased and its operability to be extended, as well as to improve the safety system of the hoisting machine.

The object of the present invention is achieved by using an overload and torsion protection device of the hoisting mechanism, characterized in that it has a hoist safety diagram selection unit, one input of which is electrically connected to the hoisting machine overload determination unit and the other intake is electrically connected to the hoisting actual stability control unit. to the lifting unit stopping unit, whereby the actual stability of the lifting mechanism is monitored by determining the bearing area between the supports and monitoring the position of the total center of gravity in this area.

It is expedient to use the OR gate in the device to protect the hoist against overload and torsion as the selection unit for the hoist safety diagram.

It is recommended that the lifting gear overload and torsion protection device be equipped with a basic JA gate and an auxiliary AND gate, some inputs of which are connected to the lifting gear overload determination unit and the lifting gear actual stability control unit, respectively, when 3 83205 their outputs are connected to the OR gate. with an output connected to the second input of the AND auxiliary port and a transmitter which transmits data from the boom angle of the hoist and the output of which is connected to the input of the inverter and to the second input of the basic AND port.

The present invention takes into account the contour conditions of the supporting structure of the crane, which improves the accuracy of the device and the reliability of the safety system of the lifting mechanism.

In addition, the invention alternatively makes it possible to determine the overload of the hoisting machine or to monitor its actual severity, thus expanding the operating possibilities of the device.

The invention will become more apparent from the following detailed description of its exemplary embodiments with reference to the accompanying drawings, in which: Figure 1 is a block diagram of a device for protecting a hoisting machine from overload and torsion according to the invention; Fig. 2 is a block diagram of a lifting mechanism according to the invention, shown in Fig. 1, against overload and torsion protection, with AND gates; Fig. 3 is a schematic diagram of the operation of a device for cranes, shown in Figs. 1 and 2, which protects the lifting machinery from overload and torsion and has a rectangular outline of the supporting structure; Fig. 4 is a schematic diagram of the operation of a device for cranes, shown in Figs. 1 and 2, which protects the lifting machinery from overload and torsion and has a triangular contour of the supporting structure.

The lifting gear overload and torsion protection device comprises a lifting gear overload determining unit 1 (Fig. 1) and a lifting gear actual stability control unit 2, the inputs 3 and 4 of the lifting gear safety diagram selection unit 5 being connected to the outputs of both units 83 and 85, respectively. One input 7 of the lifting mechanism stopping unit 6 is connected to the output of the unit 5.

According to another embodiment, the device for protecting the hoisting gear from overload and torsion further comprises a main AND gate 8 (Fig. 2) and an auxiliary AND gate 9, the inputs 10 and 11 of which are connected to units 1 and 2, respectively. 16 are connected to the second inputs 12 and 13 of the AND gates 8 and 9, respectively. The input 17 of the inverter 16 is connected to the output 15 of the transmitter 14. The outputs of the AND gates 8 and 9 are connected to the inputs 3 and 4 of the unit 5, respectively.

Fig. 3 shows an operation diagram of a crane protection device for cranes when the contour of the supporting structure of the crane is rectangular, the load on the hook remaining unchanged, in which figure the rectangular contour 18 of the supporting structure is a predetermined load curve and contour 19.

Fig. 4 shows a flow chart of a device for protecting a crane lifting gear against overload and tipping when the outline of the supporting structure of the crane is triangular, the hooked load remaining unchanged, in which the triangular contour 20 of the supporting structure is 23 and 24.

The device for protecting the lifting gear against overload and torsion works as follows in the case of the protection of a pneumatically operated hydraulic crane with a swinging boom.

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The crane overload determination unit 1 (Fig. 1) is connected simultaneously with the crane actual stability monitoring unit 2. Unit 1 protects the crane from the distances defined by contour 18 (Fig. 3) or 20 (Fig. 4), while unit 2 in turn monitors the actual stability of the crane, i.e. performs pre-securing from the distances defined by contour 19 (Fig. 3 and 4).

The signals from units 1 and 2 go to the inputs 3 and 4 of the OR gate 5, respectively. The OR gate 5 sends a control signal which goes to the input 7 of the crane stop unit 6.

The device thus operates in accordance with the contour 19 (Fig. 3) and the contour defined by the curve 23 (Fig. 4) of the contour 19 and the straight line between the points 21 and 22 of the contour 20.

In some cases, it makes sense for the signals to come from units 1 and 2 alternately.

When the angle of the boom is large with respect to the horizontal, when the safe position of the crane is determined by its strength, the signal comes from unit 1 (Fig. 2). At the given small angles of the boom with respect to the horizontal, when the safe position of the crane is determined by its stability, the signal comes from unit 2.

The signals thus come alternately from units 1 and 2.

The signal from unit 1 goes to the input of the AND basic gate 8. From the output 15 of the crane boom angle data transmitter 14 the signal goes to the second input of the AND gate 8. The latter signal goes to the input of the OR gate 5. The OR gate sends the signal to the input of the unit 6 7 to start it. At the same time, the output 15 of the transmitter 14 enters the signal at the input 17 of the inverter 16 and goes from there to the input 13 of the AND gate 9 and "prevents" the signal from the unit 2 via the AND gate 9 to the input 4 of the OR gate 5.

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When the angle of the boom is small, the transmitter 14 does not transmit a signal, whereby the signal from the unit 1 through the AND gate 8 is blocked. At the same time, the inverter 16 sends an "accept signal" to the input 13 of the AND gate 9 so that the signal can pass from the unit 2 via the AND gate 9 to the input 4 of the OR gate 5. The OR gate 5 sends a signal to the input 6 of the unit 6 to start said unit.

The present invention makes it possible to monitor the stable position of a crane in order to make its safety system more reliable.

Claims (3)

7 83205 A device for protecting a hoisting machine from overload and tipping, the device comprising electrically interconnected a hoisting machine overload determining unit (1), a hoisting stop unit (6) and a hoisting actual stability control unit (2), characterized in that it has a hoisting safety scheme selection unit (5). the second input (3) is electrically connected to the hoist overload determination unit (1) and the second input (4) is electrically connected to the hoist actual stability control unit (2) and the output is connected to the hoist stop unit (6), whereby the actual hoist stability control is determined by determining the bearing area and monitoring the position of the total center of gravity in this area. Device according to Claim 1, characterized in that an OR gate (5) is used as the safety diagram selection unit for the hoisting machine. Device according to Claim 2, characterized in that it comprises a main AND gate (8) and an additional AND gate (9), the inputs (10, 11) of which are connected to the hoist overload determining unit (1) and the hoist actual stability monitoring unit (2), respectively. ) and outputs to the OR gate (5), an inverter (16) whose output is connected to the second input (13) of the AND auxiliary gate (9), and a boom angle data transmitter (14) whose output (15) is connected to the inverter (16) to the input (17) and to the second input (12) of the AND basic port (8). 8 83205