CN108975192B - A double-brake electric hoist fault emergency load safety release system and method - Google Patents

Abstract

The invention discloses a system and method for safely releasing a double-brake electric hoist fault emergency load. The invention is used to solve the controllable and safe release of the hoisting load of the double-brake electric hoist crane under the condition of electrical failure or power grid power failure. When the electric hoist crane with double brakes has an electrical failure or an emergency in the power grid, the emergency power box is used to satisfy the independent self-power supply of the device, first control the second brake to open, and then use the cone motor to brake the manual operating mechanism to slowly lower the heavy object ;The speed measuring device measures the descending speed of the heavy object; when the descending speed of the heavy object is close to the set value, it will give an audible and visual alarm through the overspeed control box, and control the conical motor to brake the manual operating mechanism in the opposite direction; once the descending speed of the heavy object exceeds the set value When the value is reached, the second brake is powered off by the overspeed control device, and the load stops descending to ensure the safety of the emergency descending process.

Description

A double-brake electric hoist fault emergency load safety release system and method

technical field

The invention belongs to the technical field of hoisting machinery, and in particular relates to a system and method for safely releasing a double-brake electric hoist fault emergency load, which is suitable for realizing the controllable and safe release of the hoisting load in the event of an electrical fault of a crane or a power outage of the power grid.

Background technique

The lifting mechanism of the electric hoist crane for hoisting special equipment is equipped with two sets of brakes. The first brake is a conical motor brake. Its operating principle is that the inner surface of the stator and the outer surface of the rotor are both conical. When the circuit is turned on, the motor In addition to rotating, the shaft also moves axially. The stator and rotor iron cores generate axial magnetic pulling force to move the rotor axially and compress the spring, so that the fan brake wheel is separated from the brake seat (rear cover or end cover). The axial magnetic pulling force compresses the brake spring, and makes the brake wheel produce axial displacement to separate from the brake seat to achieve normal operation; when the circuit is cut off, the axial magnetic pulling force is small, and under the action of the spring pressure, the rotor drives The fan brake wheel is reset together, so that the brake wheel presses the brake seat and generates friction braking torque, so that the motor stops rotating to achieve the purpose of braking. The second brake is an electro-magnetic disc brake, which is a protective brake, an electromagnetic multi-disc type normally closed brake, the working voltage of the electromagnet is a DC voltage, and the general braking action lags the motor cone braking by 0.3 seconds. When the motor brake fails, the safety brake can effectively brake the motor to ensure the safe and reliable use of the motor.

At present, for this type of hoist crane, in the event of an electrical failure or a power failure in the power grid, both sets of brakes are in the braking state, and they cannot be operated to release the heavy objects. The heavy objects can only be suspended in the air and must be loaded. Maintenance, there is a great safety hazard.

Chinese utility model patent CN201010479Y electric hoist front brake manual release device, Chinese utility model patent CN201010480Y electric hoist rear brake manual release device, respectively design and provide a manual release device for marine electric hoist that does not require electricity, is simple to operate, safe and reliable . However, the device only opens the brake of the cone motor, and the brake is opened by direct manual pulling or pressing operation. The opening process of the brake is not easy to control, and there is no safety protection, so there is a potential safety hazard.

Chinese utility model patent CN201220770Y double-brake electric hoist second brake automatic control device, provides a double-brake electric hoist second brake automatic control device with the function of the second brake can safely lower heavy objects after braking. However, the premise of the application of the device is that the first brake fails, and during the operation, the process of lowering the heavy object is controlled by human operation, and there is no safety protection, so there is a potential safety hazard.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the existing defects of the double-brake electric hoist crane, and to provide a double-brake electric hoist fault emergency load safety release system and method, which can quickly and safely release the electric hoist in the event of an electrical fault of the crane or a power outage of the power grid. Lift the load and lower it.

The present invention adopts following technical scheme to realize:

A double-brake electric hoist fault emergency load safety release system, comprising an emergency power supply box, a conical motor brake manual operating mechanism, a rotational speed measurement sensing device and an overspeed control device; wherein,

When working, the rotational speed measurement sensing device is installed on the reel, which supplies power through the emergency power box and controls the opening of the second brake, and then manually operates the conical motor brake. The rotational speed measurement sensor device installed on the reel measures the lowering speed of the heavy object; when the lowering speed of the heavy object is close to the set value, the sound and light alarm is given by the overspeed control device, and the conical motor is manually operated in the opposite direction to brake the manual operating mechanism. Slow down the lowering speed of heavy objects; once the emergency lowering speed exceeds the set value, the second brake will be powered off through the overspeed control device, and the heavy objects will stop falling to ensure the safety of the emergency lowering process.

A further improvement of the present invention is that the emergency power supply box includes a charging module, a battery pack, a DC-DC module and a power switch. During operation, the input voltage is 220V/50Hz for charging the battery pack, and the outputs U1+ and U1- are DC12V voltage to provide The speed measurement sensor device and the overspeed control device are powered, the output U2+ and U2- are DC168V voltage for opening the second brake, and the ports a1 and a2 are the control on-off ports of the DC168V voltage.

A further improvement of the present invention is that the overspeed control device includes a speed setting module, a single-chip microcomputer, a signal acquisition and processing module, a speed display module, a relay control module and a power supply module, and the speed setting module can set the maximum speed value according to the speed control requirements, and the single-chip microcomputer can Judging according to the set speed value, when overspeeding, a control signal is given to control the on-off of the relay control module circuit, that is, the on-off of the power supply circuit of the second brake is controlled to realize the overspeed control function of heavy objects.

A further improvement of the present invention lies in that the rotational speed measurement sensor device includes a Hall element, a magnetic steel and a clamp, wherein a clamp is fastened at the end of the lifted drum, and several Magnetic steel, and a Hall element is installed at the end of the drum near the clamp. During operation, when the clamp is driven to rotate by the drum, the Hall element is affected by the magnetic field generated by the magnetic steel, and outputs a pulse signal, signal Its frequency is proportional to the rotational speed, and this signal is input to the overspeed control device for detection.

A further improvement of the present invention is that the clamp includes two upper and lower semicircular structures, which are fastened and installed by bolts.

A further improvement of the present invention is that the number of magnetic steels is 16.

A method for safely releasing a fault emergency load of a double-brake electric hoist, the method is based on the above-mentioned system for safely releasing a fault emergency load of a double-brake electric hoist, and includes the following steps:

a) Correspondingly connect the DC output terminals U2+ and U2- of the emergency power box with the second brake control terminal;

b) Correspondingly connect the control terminals a1 and a2 of the emergency power box with the terminals a1 and a2 of the overspeed control device;

c) Install a rotational speed measuring device on the drum of the hoisting mechanism;

d) Connect the cable ends c1-c3 of the Hall element to the terminals c1-c3 of the overspeed control device;

e) Connect the power supply cable from the emergency power box to the overspeed control device;

f) Turn on the power switch of the emergency power box and the switch of the overspeed control device;

g) Operate the conical motor to brake the manual operating mechanism until the motor shaft rotates slowly and maintain the handle operating position, and lower the suspended counterweight to the bearing device;

h) Withdrawal of equipment.

The present invention has following beneficial technical effect:

The invention provides a double-brake electric hoist fault emergency load safety release system. For double-brake electric hoist cranes, the combination of manual control and speed measurement electric control is applied to the emergency load release, and the scheme of speed measurement and overspeed control is adopted. , to ensure that the speed of the emergency release process is safe and controllable.

Further, the emergency power supply box is used to realize that the power supply system of the original equipment is not used, and the second brake is released and the power supply is turned on in an emergency, including a charging module, a battery pack, a DC-DC module, and a power switch. Turn the AC220V voltage into the low voltage required for charging, and control the charging of the battery pack; when the charging amount meets the index requirements, stop the battery pack charging, and indicate a signal that can work normally, and the electric hoist-type second brake system can be realized through switch control. automatically release the control operation.

Further, the rotational speed measurement sensing device adopts a non-contact rotational speed measurement method-disc magnetic measurement, and a plurality of permanent magnets are fixed on the edge of the rotating body turntable. The turntable rotates with the measured body, and the magnetic steel will also follow. Synchronous rotation, install a Hall element near the turntable. When the turntable rotates with the measured object, the Hall element is affected by the magnetic field generated by the magnetic steel, and outputs a pulse signal. The overspeed control device can calculate the period or frequency of the pulse by measuring Rotating speed.

Further, the overspeed control device sets the maximum speed value according to the speed control requirements, and the single-chip microcomputer can judge according to the set speed value, and when overspeeding, a control signal is given to control the on-off of the relay circuit, so as to realize the overspeed control function.

The invention provides a method for safely releasing an emergency load of a double-brake electric hoist failure. Steps a to b are preparations in advance and do not affect the normal working state of the crane. Steps c to h are the operation of applying an emergency release device when the hoisting mechanism fails. The process; among them, in the event of an electrical failure of the double-brake electric hoist crane or a power outage of the power grid, the hoisting load can be quickly and safely lowered by using its own power supply device; the lowering speed of the hoisting load is monitored and controlled in real time during the lowering process, which ensures the emergency release process. The speed of the hoist is safe and controllable, avoiding the overspeed phenomenon during the emergency release of the load; making full use of the mechanical structure of the double-brake electric hoist crane, using the installation holes based on the conical motor fan cover, the outer clamp of the drum, and the existing fixing bolts to install The combined installation method ensures the ease of use of the emergency release device in actual installation, and facilitates the technical improvement of existing equipment or emergency disposal in case of failure.

Description of drawings

Figure 1 is the working principle diagram of the emergency release device of the double-brake electric hoist crane.

Figure 2 is a schematic block diagram of the emergency power box.

Fig. 3 is the principle block diagram of the overspeed control device.

Figure 4 is a schematic diagram of the rotational speed measurement sensor device and its installation.

Description of reference numerals: 1-emergency power box, 11-charging module, 12-battery pack, 13-DC-DC module, 14-power switch;

2-Conical motor brake manual operating mechanism;

3-speed measurement sensor device, 31-Hall element, 32-magnetic steel, 33-clamp;

4-overspeed control device, 41-speed setting module, 42-microcomputer, 43-signal acquisition and processing module, 44-speed display module, 45-relay control module, 46-power supply module, 47-switch;

5-Reel.

Detailed ways

Typical examples of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figure 1, the present invention provides a double-brake electric hoist fault emergency load safety release system, including an emergency power box 1, a conical motor brake manual operating mechanism 2, a rotational speed measurement sensing device 3 and an overspeed control device 4.

When working, firstly control the opening of the second brake through the emergency power supply box 1, and then manually operate the conical brake operating mechanism 2 to gradually open the first brake, so that the heavy object slowly descends, and the rotational speed measurement sensor device 3 installed on the reel is at the same time. Measure the lowering speed of the heavy object; when the lowering speed of the heavy object is close to the set value, the overspeed control device 4 will give a sound and light alarm, and manually operate the cone brake operating mechanism 2 in the opposite direction to slow down the lowering speed of the heavy object; once the emergency lowering speed When the set value is exceeded, the power-off control of the second brake is performed by the overspeed control device 4, and the heavy objects stop descending, ensuring the safety of the emergency lowering process.

As shown in Figure 2, the emergency power box 1 has a built-in charging module 11, a battery pack 12, a DC-DC module 13, and a power switch 14. The input voltage is 220V/50Hz for charging the battery pack 12, and the outputs U1+ and U1- are DC12V. The voltage supplies power to the rotational speed measurement sensor device 3 and the overspeed control device 4. The outputs U2+ and U2- are the DC168V voltage for opening the second brake, and the ports a1 and a2 are the DC168V voltage control on-off ports.

As shown in FIG. 3 , the overspeed control device 4 includes a speed setting module 41 , a single-chip microcomputer 42 , a signal acquisition and processing module 43 , a speed display module 44 , a relay control module 45 , and a power supply module 46 , and the speed setting module 41 can be controlled according to speed control requirements. Set the maximum speed value, the speed setting range is 0.1~9.9r/min, the single chip 42 can judge according to the set speed value, when the speed is over, it will give a control signal to control the circuit of the relay control module 45 to be on and off, that is, to control the power supply circuit of the second brake The on-off of the heavy object is realized, and the overspeed control function is realized.

As shown in Figure 4, the rotational speed measurement sensor device and installation schematic diagram, a fixing device with a clamp 33 structure is used at the end of the hoisting drum 5. The clamp is in the form of upper and lower halves, which are fastened and installed by bolts. 16 magnetic steels 32 are evenly arranged concentrically. As the reel 5 rotates, the magnetic steels 32 will also rotate synchronously. A Hall element 31 is installed near the clamp 33. When the clamp 33 rotates with the reel 5, the Hall The element 31 is affected by the magnetic field generated by the magnetic steel 32, and outputs a pulse signal whose frequency is proportional to the rotational speed. The signal is input to the overspeed control device 4 for detection.

The working principle of the present invention is as follows:

When the electrical failure of the crane or the power failure of the power grid occurs, the emergency power supply can be used to satisfy the independent self-supply of the emergency release device. First, the second brake is controlled to open, and then the conical brake is manually operated to slowly lower the weight; The rotational speed measurement principle realizes the emergency lowering speed measurement; when the emergency lowering speed is close to the set value, an audible and visual alarm is given through the emergency release control box, and the operation of the cone brake release device is stopped; once the emergency lowering speed exceeds the set value, the overspeed The protection control circuit controls the power off of the second brake, and the load stops descending to ensure the safety of the emergency descending process.

A method for safely releasing a fault emergency load of a double-brake electric hoist provided by the present invention comprises the following steps:

a) Correspondingly connect the DC output terminals U2+ and U2- of the emergency power box 1 with the second brake control terminal;

b) Correspondingly connect the control terminals a1 and a2 of the emergency power box 1 to the terminals a1 and a2 of the overspeed control device 4;

c) Install the rotational speed measuring device 3 on the drum 5 of the hoisting mechanism;

d) Connect the cable ends c1-c3 of the Hall element 31 to the terminals c1-c3 of the overspeed control device 4;

e) Connect the power supply cable of the emergency power box 1 to the overspeed control device 4;

f) Turn on the power switch 14 of the emergency power box 1 and the switch 47 of the overspeed control device 4;

g) Operate the conical motor brake manual operating mechanism 2 until the motor shaft rotates slowly and maintain the handle operation position, and lower the suspended counterweight to the bearing device;

h) Withdrawal of equipment.

Wherein, steps a to b are preparations in advance, which do not affect the normal working state of the crane, and steps c to h are the operation procedures of applying the emergency release device when the hoisting mechanism fails.

Claims (4)

1. A double-brake electric hoist fault emergency load safety release system is characterized by comprising an emergency power box (1), a conical motor brake manual operation mechanism (2), a rotating speed measurement sensing device (3) and an overspeed control device (4); wherein,

the emergency power box (1) comprises a charging module (11), a battery pack (12), a DC-DC module (13) and a power switch (14), when the emergency power box works, 220V/50Hz voltage is input to charge the battery pack (12), U1+ and U1-DC 12V voltage is output to supply power to the rotating speed measuring sensing device (3) and the overspeed control device (4), U2+ and U2-DC 168V voltage are output to open a second brake, and ports a1 and a2 are control on-off ports of the DC168V voltage;

the overspeed control device (4) comprises a speed setting module (41), a single chip microcomputer (42), a signal acquisition and processing module (43), a speed display module (44), a relay control module (45) and a power supply module (46), wherein the speed setting module (41) can set a maximum speed value according to a speed control requirement, the single chip microcomputer (42) can judge according to the set speed value, a control signal is given out when overspeed occurs, the on-off of a circuit of the relay control module (45) is controlled, namely the on-off of a power supply circuit of a second brake is controlled, and the overspeed control function of weight lowering is realized;

the rotating speed measuring sensing device (3) comprises a Hall element (31), magnetic steel (32) and a clamp (33), wherein the clamp (33) is fastened at the end part of a lifted winding drum (5), a plurality of magnetic steel (32) are concentrically and uniformly arranged in the circumferential direction of the clamp (33), the Hall element (31) is installed at the end part of the winding drum (5) close to the clamp (33), when the clamp (33) rotates along with the driving of the winding drum (5) in work, the Hall element (31) is influenced by a magnetic field generated by the magnetic steel (32), a pulse signal is output, the frequency of the signal is in direct proportion to the rotating speed, and the signal is input into the overspeed control device (4) for detection;

the rotating speed measuring sensing device (3) is arranged on the winding drum (5), supplies power through the emergency power box (1) and controls the second brake to be opened, then the conical motor is manually operated to brake the manual operating mechanism (2), the first brake is gradually opened, the heavy object is slowly descended, and meanwhile the rotating speed measuring sensing device (3) arranged on the winding drum (5) measures the descending speed of the heavy object; when the weight lowering speed is close to a set value, audible and visual alarm is carried out through the overspeed control device (4), the conical motor is manually operated in the opposite direction to brake the manual operation mechanism (2), and the weight lowering speed is slowed down; once when emergent speed of transferring surpassed the setting value, carry out outage control to the second stopper through overspeed control device (4), the heavy object stops to descend, ensures emergent process safety of transferring.

2. The double-brake electric hoist fault emergency load safety release system as claimed in claim 1, wherein the clamp (33) comprises upper and lower semicircular structures and is fastened and installed by bolts.

3. The double-brake electric block fault emergency load safety release system according to claim 1, characterized in that the number of the magnetic steels (32) is 16.

4. A double-brake electric hoist fault emergency load safety release method, which is based on the double-brake electric hoist fault emergency load safety release system of claim 1, and comprises the following steps:

a) correspondingly connecting the direct-current output terminals U2+ and U2-of the emergency power box (1) with the control terminal of the second brake;

b) correspondingly connecting control terminals a1 and a2 of an emergency power box (1) with terminals a1 and a2 of an overspeed control device (4);

c) a rotating speed measuring device (3) is arranged on a winding drum (5) of the hoisting mechanism;

d) connecting the cable end c1-c3 of the Hall element (31) with the terminals c1-c3 of the overspeed control device (4);

e) a power supply cable for connecting the emergency power box (1) to the overspeed control device (4);

f) turning on a power switch (14) of the emergency power box (1) and a switch (47) of the overspeed control device (4);

g) operating the conical motor brake manual operating mechanism (2) until the motor shaft slowly rotates, keeping the handle operating position, and lowering the hung counterweight onto the bearing device;

h) and (5) withdrawing the equipment.

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