A quayside container crane emergency system and quayside container crane

Abstract

The utility model discloses a kind of emergency system and shore bridge trolley of shore bridge, it is related to port mechanical equipment technical field, comprising: emergency power supply circuit and brake mechanism control circuit;Wherein, emergency power supply circuit is set in the power input end of shore bridge trolley, brake mechanism control circuit is set in the control end of shore bridge trolley;Emergency power supply circuit includes phase sequence automatic switching control circuit and be used for controlling the on-off of phase sequence automatic switching control circuit emergency power supply switch;Brake mechanism control circuit includes emergency control switch, emergency control relay, wheel clamp ware control relay, brake control relay and cable reel control relay.The utility model alleviates the technical problem of time-consuming and laborious, low efficiency of manual operation in emergency in prior art.

Description

Technical Field

[0001] This utility model relates to the field of port machinery and equipment technology, specifically to an emergency system for quay cranes and a quay crane. Background Technology

[0002] Quay cranes (shore container cranes) are the core equipment for loading and unloading containers at ports. Their trolley mechanisms are responsible for moving along the quay tracks to change container positions. In actual operation, various emergencies may occur, such as main power failure, control system failure, motor failure, or natural disasters, which may prevent the trolley from moving normally, creating safety hazards for liner ships berthing and unberthing.

[0003] Existing quay crane trolley systems typically rely on main power and control systems. When a serious malfunction occurs and technicians cannot repair it quickly, the crane needs to be towed. Towing requires manually engaging the braking mechanisms, including hydraulic wheel clamps and electric brakes. Taking the CCT11-13# quay crane as an example, its trolley mechanism has 16 wheel clamps and 20 electric brakes. Manually engaging these mechanisms in such situations would be time-consuming, labor-intensive, and inefficient. Utility Model Content

[0004] The purpose of this utility model is to provide an emergency system for quay cranes and a quay crane to solve at least one of the above-mentioned technical problems.

[0005] In a first aspect, this utility model provides an emergency system for a quay crane, comprising: an emergency power supply circuit and a braking mechanism control circuit; wherein, the emergency power supply circuit is located at the power input terminal of the quay crane, and the braking mechanism control circuit is located at the control terminal of the quay crane; the emergency power supply circuit includes a phase sequence automatic switching control circuit and an emergency power supply switch for controlling the on / off state of the phase sequence automatic switching control circuit; the input terminal of the phase sequence automatic switching control circuit is connected to the power input terminal of an adjacent quay crane, and the output terminal of the phase sequence automatic switching control circuit is connected to the power input terminal of the quay crane; the braking mechanism... The control circuit includes an emergency control switch, an emergency control relay, a wheel clamp control relay, a brake control relay, and a cable reel control relay. The coils of the emergency control relay, the wheel clamp control relay, the brake control relay, and the cable reel control relay are connected in parallel and then in series with the emergency control switch. The emergency control relay, the wheel clamp control relay, the brake control relay, and the cable reel control relay are respectively connected to the main control circuit, the wheel clamp control circuit, the brake control circuit, and the cable reel control circuit of the quay crane.

[0006] Optionally, the main control circuit includes a PLC operating point, two reactor fuse detection points, a control closing point, a main control software interlock point, and multiple emergency stop switches connected in series; the normally open terminal of the emergency control relay is connected in parallel with the circuit formed by the PLC operating point, reactor fuse detection point, and main control software interlock point in the main control circuit of the quay crane.

[0007] Optionally, the coil of the wheel clamp control relay is also connected in series with the wheel clamp emergency control switch, the normally closed terminal of the wheel clamp control relay is connected to the PLC control circuit, and the normally open terminal of the wheel clamp control relay is connected to the wheel clamp control circuit.

[0008] Optionally, the coil of the brake control relay is also connected in series with the brake emergency control switch; the brake control circuit includes multiple converter preparation points, multiple frequency converter preparation points, and a gantry crane stop switch connected in series; the normally closed contact of the brake control relay is connected to the PLC control circuit, and the normally open contact of the brake control relay is connected in parallel with the circuit composed of multiple converter preparation points and multiple frequency converter preparation points.

[0009] Optionally, the coil of the cable reel control relay is also connected in series with the cable reel emergency control switch, the normally closed contact of the cable reel control relay is connected to the PLC control circuit, and the normally open contact of the cable reel control relay is connected to the cable reel control circuit.

[0010] Secondly, this utility model embodiment also provides a quay crane trolley, including the quay crane trolley emergency system provided in this utility model embodiment.

[0011] This utility model provides an emergency system for quay cranes and a quay crane itself, which can quickly open the braking mechanism of the quay crane in emergency situations, enabling the quay crane to move quickly and safely. This alleviates the technical problems of existing technologies where manual operation is required in emergency situations, which is time-consuming, labor-intensive, and inefficient. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 A circuit diagram of an emergency power supply circuit provided for an embodiment of this utility model; Figure 2A circuit diagram of a braking mechanism control circuit provided for an embodiment of the utility model; Figure 3 A circuit diagram of a clamping wheel control circuit provided for an embodiment of this utility model; Figure 4 A schematic diagram of the control principle of the solenoid valve circuit for a hydraulic clamping wheel is provided for an embodiment of this utility model; Figure 5 A schematic diagram of the main control circuit of a brake control circuit provided in an embodiment of this utility model; Figure 6 A schematic diagram of the power supply circuit breaker detection section of a brake control circuit provided for an embodiment of this utility model; Figure 7 A schematic diagram of the detection section of a cable reel control circuit provided for an embodiment of this utility model; Figure 8 This is a schematic diagram of the control section of a cable reel control circuit provided in an embodiment of the present invention.

[0014] In the diagram: 1. Automatic phase sequence switching control circuit; 2. Emergency power supply switch; 3. Power input terminal for adjacent quay crane trolleys; 4. Emergency control switch; 5. Coil of emergency control relay; 6. Coil of wheel clamp control relay; 7. Coil of brake control relay; 71. Coil of first brake control relay; 72. Coil of second brake control relay; 8. Coil of cable reel control relay; 81. Coil of first cable reel control relay; 82. Coil of second cable reel control relay; 83. Coil of third cable reel control relay; 84. Coil of fourth cable reel control relay; 9. Main control relay coil; 10. PLC operating point; 11. Two reactor fuse detection points; 12. Control connection point; 13. Main control software interlock point; 14. Normally open contact of emergency control relay. 15. Driver's cab emergency stop switch; 16. Engine room emergency stop switch; 17. Quay crane trolley seaside emergency stop switch; 18. Quay crane trolley landside emergency stop switch; 19. Front beam emergency stop switch; 20. Standby switch; 21. Elevation room emergency stop switch; 22. Quay crane trolley operator station emergency stop switch; 23. Rear beam emergency stop switch; 24. Electrical room emergency stop switch; 25. Wheel clamp emergency control switch; 26. Wheel clamp control relay composite contact; 27. Brake emergency control switch; 28. 29. Converter standby point; 30. Inverter standby point; 31. Quay crane trolley left stop switch; 32. Quay crane trolley right stop switch; 33. Brake control relay normally closed contact; 34. Brake control relay normally open contact; 35. First brake control relay coil composite contact. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] This utility model provides an emergency system for a quay crane, including an emergency power supply circuit and a braking mechanism control circuit; wherein, the emergency power supply circuit is located at the power input terminal of the quay crane, and the braking mechanism control circuit is located at the control terminal of the quay crane.

[0017] Specifically, when a quay crane's trolley mechanism malfunctions, preventing the crane from moving, a selector switch is used to switch to the quay crane's emergency system. If the power supply system fails, power is obtained from an adjacent quay crane. In cabinet #73.2 of the quay crane's electrical room, the auxiliary transformer circuit breaker 211MCB is pulled down, and the mechanical interlock lever is pushed to lock at the auxiliary transformer circuit breaker 211MCB to prevent accidents caused by human error. The shore power supply circuit then supplies power to the faulty quay crane, and the shore power circuit breaker 212MCB is closed. The designed emergency control system quickly opens the braking and other mechanisms, allowing the equipment to be moved by dragging it from an adjacent quay crane.

[0018] Figure 1 This is a circuit diagram of an emergency power supply circuit according to an embodiment of the present utility model. Figure 1 As shown, the emergency power supply circuit includes an automatic phase sequence switching control circuit 1 and an emergency power supply switch 2 for controlling the on / off state of the automatic phase sequence switching control circuit 1; the input terminal of the automatic phase sequence switching control circuit 1 is connected to the power supply input terminal 3 of the adjacent quay crane, and the output terminal of the automatic phase sequence switching control circuit 1 is connected to the power supply input terminal of the quay crane.

[0019] Specifically, to ensure that the phase sequence of the supplied power supply and the faulty shore crane motor are consistent, and to prevent motor reversal and equipment damage due to incorrect phase sequence, an automatic phase sequence switching control circuit 1 is added above the shore power socket, such as... Figure 1 As shown in the dashed box, the phase sequence can be automatically switched when an inconsistency is detected.

[0020] Specifically, if the power supply system of the quay crane fails, after the connecting cable is reconnected, close the emergency power supply switch 2 (i.e., Figure 1 When Q1 is activated, the initial phase sequence contactor KM1 is energized and its main contacts close, and the emergency power is transmitted to the bridge.

[0021] When the phase sequence protection relay detects that the phase sequence is normal, that is, consistent with the phase sequence on the bridge, its normally open contact 1X closes, the coil of intermediate relay KA1 is energized, its normally closed contact KA1 opens, the time relay KT1 and the phase commutation contactor KM2 are not energized, and the power supply maintains the current phase sequence.

[0022] When the phase sequence protection relay detects an abnormal phase sequence, its normally open contact 1X will not close, the intermediate relay KA1 coil will not be energized, and its normally closed contact KA1 will remain normally closed. This energizes the time relay KT1 coil, causing its normally closed contact to open and its normally open contact to close. This de-energizes the main contactor KM1 coil, causing its main contact KM1 to open. The normally closed auxiliary contact KM1 then returns to its closed state, energizing the main contactor KM2 coil and closing its main contact KM2, thus switching the power supply phase sequence. This achieves the automatic phase sequence switching function.

[0023] Figure 2 This is a circuit diagram of a braking mechanism control circuit according to an embodiment of the present invention. Figure 2 As shown, the braking mechanism control circuit includes an emergency control switch 4, an emergency control relay, a wheel clamp control relay, a brake control relay, and a cable reel control relay. The coils 5 of the emergency control relay, 6 of the wheel clamp control relay, 7 of the brake control relay, and 8 of the cable reel control relay are connected in parallel and then in series with the emergency control switch 4. The emergency control relay, wheel clamp control relay, brake control relay, and cable reel control relay are respectively connected to the main control circuit of the quay crane, the wheel clamp control circuit, the brake control circuit, and the cable reel control circuit.

[0024] Specifically, such as Figure 2 As shown, the main control circuit includes a PLC operating point 10, two reactor fuse detection points 11, a control closing point 12, a main control software interlock point 13, and multiple emergency stop switches connected in series. The normally open terminal 14 of the emergency control relay is connected in parallel with the circuit formed by the PLC operating point 10, reactor fuse detection point 11, and main control software interlock point 13 in the main control circuit of the quay crane. The emergency stop switches include: driver's cab emergency stop switch 15, engine room emergency stop switch 16, quay crane seaside emergency stop switch 17, quay crane landside emergency stop switch 18, front beam emergency stop switch 19, standby switch 20, elevation room emergency stop switch 21, quay crane operator station emergency stop switch 22, rear beam emergency stop switch 23, and electrical room emergency stop switch 24. Specifically, a main control relay coil 9 is also installed at the end of the main control circuit to control the activation and deactivation of the control closing point 12.

[0025] Specifically, when the gantry crane emergency system is needed, the emergency control switch 4 is turned to the open position. The coil 5 of the emergency control relay is energized and engages, causing the normally open contact 14 of the emergency control relay to short-circuit the PLC operating point 10, the reactor fuse detection point 11, and the main control software interlock point 13 in the main control system, while retaining all emergency stop switches. If the emergency stop switches are not disconnected, the hardware main control relay is energized and supplies control power.

[0026] Specifically, such as Figure 2 As shown, the coil 6 of the wheel clamp control relay is also connected in series with the wheel clamp emergency control switch 25.

[0027] Figure 3 This is a circuit diagram of a clamping wheel control circuit according to an embodiment of the present utility model. Figure 3 As shown, the composite contact 26 of the wheel clamp control relay includes a normally closed contact and a normally open contact. The normally closed contact of the wheel clamp control relay is connected to the PLC control circuit, and the normally open contact of the wheel clamp control relay is connected to the wheel clamp control circuit.

[0028] Specifically, to open the hydraulic wheel clamp, the hydraulic station needs to be pressurized first, and then the wheel clamp is opened by controlling the solenoid valve. The trolley mechanism has two wheel clamp hydraulic stations, one on the land and one on the sea.

[0029] like Figure 3 As shown, the wheel clamp control circuit provided in this embodiment of the utility model connects a relay circuit in parallel with the original low-voltage, high-voltage, high-temperature, circuit breaker, and thermal relay PLC input circuits for emergency control. Here, LP is the low-voltage point, HP is the high-voltage point, HT is the high-temperature point, and 561X and 562X are the corresponding circuit breaker and motor thermal relay detection points.

[0030] The operating conditions of the land and sea hydraulic stations are the same. When the wheel clamp selector switch is turned on, the coil 6 of the wheel clamp control relay is energized, the composite contact 26 of the wheel clamp control relay is activated, the normally closed contact opens, cutting off the original PLC control circuit, and the normally open contact closes, switching to the emergency control circuit.

[0031] If the hydraulic station system pressure does not reach the low pressure point, the low pressure point LP is in a closed state. The coil of the intermediate relay LP is energized and closed, and its normally closed contact LP is opened. The hydraulic pump contactors 561MC and 562MC will not be energized, and the hydraulic pump will not start to pressurize.

[0032] When the system pressure reaches the low-pressure point, the normally closed low-pressure contact LP opens, de-energizing the intermediate relay LP coil. Its normally closed contact LP then closes again, energizing the coils of hydraulic pump contactors 561MC and 562MC. Their auxiliary normally open contacts close, short-circuiting the low-pressure point and creating a self-locking mechanism. The hydraulic pump starts to replenish pressure. When the system pressure reaches the high-pressure point, the normally closed high-pressure contact HP opens, de-energizing the HP coil. Its normally open contact HP then opens, de-energizing the coils of 561MC and 562MC, releasing the self-locking mechanism, and the hydraulic pump stops operating. This cycle of pressure replenishment continues.

[0033] Figure 4 This is a circuit control schematic diagram of a hydraulic clamping wheel solenoid valve according to an embodiment of the present utility model. Figure 4 As shown, when the wheel clamp selector switch is open, the compound contact 26 of the wheel clamp control relay is activated. The normally closed contact opens to cut off the original PLC control circuit, and the normally open contact closes to energize the solenoid valve coil of the hydraulic wheel clamp on the land and sea sides, causing the wheel clamp to release.

[0034] Specifically, such as Figure 2 As shown, the coil 7 of the brake control relay is also connected in series with the brake emergency control switch 27. The coil 7 of the brake control relay includes a first brake control relay coil 71 and a second brake control relay coil 72.

[0035] Figure 5 This is a schematic diagram of the main control section of a brake control circuit according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the power supply circuit breaker detection section of a brake control circuit according to an embodiment of the present invention. Figure 5 and Figure 6 As shown, the brake control circuit includes multiple converter preparation points 29, multiple frequency converter preparation points 30, and a quay crane stop switch connected in series; wherein, the quay crane stop switch includes a left quay crane stop switch 31 and a right quay crane stop switch 32. The normally closed terminal 33 of the brake control relay is connected to the PLC control circuit, and the normally open terminal 34 of the brake control relay is connected in parallel with the circuit composed of multiple converter preparation points 29 and multiple frequency converter preparation points 30.

[0036] The normally closed terminal 33 and normally open terminal 34 of the brake control relay are controlled by the coil 72 of the second brake control relay.

[0037] Specifically, when the brake selector switch is turned on, the normally open node 34 of the brake control relay is used to short-circuit multiple converter preparation points 29 and multiple frequency converter preparation points 30 in front of the main control of the trolley, as well as the main control software interlock point 13 of the trolley main control behind it, thus preserving the stop limit points on the left and right sides of the trolley.

[0038] A 225X relay circuit is connected in parallel to the original brake power circuit breaker detection circuit of the heavy vehicle. The normally closed terminal 33 of the brake control relay is used to disconnect the trip coil of the brake power circuit breaker to prevent the circuit breaker from tripping due to a contactor failure in the PLC control circuit.

[0039] Specifically, the composite node 35 of the first brake control relay coil includes a normally open node and a normally closed node. When the brake switch is turned to the open position, the normally closed node of the first brake control relay coil opens and the normally open node closes, disconnecting the original PLC control circuit and switching to the emergency control circuit. The coils of brake contactors 21B and 22B and resistor bypass contactors 21BE and 22BE are energized, opening the brake. At the same time, the normally open contacts of 21B and 22B close, energizing the coil of the time relay BRKT. After 2 seconds, the normally closed contact of BRKT opens, de-energizing the coils of resistor bypass contactors 21BE and 22BE. Its main contact 21BE opens, and a current-limiting resistor is connected in series to keep the brake open.

[0040] After the gantry crane's motor brake is released, a resistor is connected in series in the circuit, mainly for the following key reasons: 1. Reduce the braking coil current to decrease heat loss. When the brake is fully engaged, only a small holding current is needed to maintain its open state. Adding a resistor in series limits the coil current, preventing overheating caused by prolonged high current and extending the coil's lifespan.

[0041] When initially powered on, a high current (for a short time) quickly generates enough magnetic force to engage the brake; after engagement, the voltage drop across the resistor reduces the current to a maintenance level, thus saving energy.

[0042] 2. Protection and control components (such as contactors and relays) Continuously supplying a large current will accelerate contact aging. Adding a series resistor reduces the current during the holding phase, lowering the load on the contactor or relay and improving reliability.

[0043] 3. Fail-safe design If the braking circuit is de-energized, the resistor can help quickly release the magnetic field energy, ensuring that the brakes close rapidly (emergency braking) and avoiding the risk of the vehicle rolling away.

[0044] In some designs, the resistor works in conjunction with the bypass contactor: when the contactor is engaged, it short-circuites the resistor (full voltage operation); when the contactor is held, it disconnects the contactor, and the current is maintained through the resistor.

[0045] 4. Adapt to power supply voltage fluctuations The resistor can stabilize the coil's operating voltage and prevent the brake from malfunctioning due to voltage fluctuations (such as excessive current burning out the coil when the voltage is too high, or failure to keep it open when the voltage is insufficient).

[0046] 5. Economy and Simplified Design Compared to complex electronic constant current control, series resistors are a low-cost and reliable solution suitable for the harsh environments of port machinery (high humidity, salt spray, vibration).

[0047] like Figure 2 As shown, the coil 8 of the cable reel control relay is also connected in series with the cable reel emergency control switch 28. The normally closed contact of the cable reel control relay is connected to the PLC control circuit, and the normally open contact of the cable reel control relay is connected to the cable reel control circuit.

[0048] Optionally, the coil 8 of the cable reel control relay includes a first cable reel control relay coil 81, a second cable reel control relay coil 82, a third cable reel control relay coil 83, and a fourth cable reel control relay coil 84.

[0049] Figure 7 This is a schematic diagram of the detection section of a cable reel control circuit according to an embodiment of the present invention. Figure 8 This is a schematic diagram of the control section of a cable reel control circuit according to an embodiment of the present utility model. Figure 7 and Figure 8 As shown, a relay circuit is connected in parallel with the original circuit breaker and thermal relay PLC detection circuit. 551X is for the cable pulling motor, 552-555X are for the cable reel motor, 556X is for the brake, and there are also newly added relay circuits for cable reel empty point (PIT) and guide frame overtight point (HIGHTENSION).

[0050] The cable reel of the trolley has a total of 5 motors: 1 cable pulling motor 551 (without brake) and 4 cable winding motors 552-555 (with brakes 556-559). The motors and their brakes are controlled separately. The cable winding motors are connected to the gearbox via a hysteresis coupling. The output shaft of the gearbox drives the cable reel to wind the cable. When the trolley needs to wind up the cable in the direction it is traveling, all 5 motors and all brakes are opened, and the motors start running to drive the reel to wind up the cable. When the trolley needs to unwind the cable in the direction it is traveling, all motors are not started, but the brake of one motor needs to be opened, and the cable pulls the reel to unwind the cable.

[0051] When the selector switch is set to the cable reel position, the normally closed contacts controlled by the coils 81, 82, and 83 of the first cable reel control relay open and the normally open contacts close, disconnecting the original PLC control circuit and switching to the emergency control circuit. The coils 551-555MC of the five motor contactors are energized, and their normally open contacts conduct the coils 556-559MC of the four motor brakes, causing the high-voltage cable reel to start rotating and reeling in the cable.

[0052] When the selector switch is set to the cable release position, the contacts controlled by the coil 84 of the fourth cable reel control relay are energized and closed, which energizes the brake coil 556MC, opens the brake, and the trolley will rely on the cable tension to pull the reel to release the cable when it moves.

[0053] This utility model also provides a quay crane trolley, including the quay crane trolley emergency system provided in the embodiments of this utility model.

[0054] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0055] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An emergency system for quay cranes, characterized in that, include: An emergency power supply circuit and a braking mechanism control circuit; wherein, the emergency power supply circuit is located at the power input terminal of the quay crane, and the braking mechanism control circuit is located at the control terminal of the quay crane; The emergency power supply circuit includes an automatic phase sequence switching control circuit and an emergency power supply switch for controlling the on / off state of the automatic phase sequence switching control circuit; the input terminal of the automatic phase sequence switching control circuit is connected to the power supply input terminal of the adjacent quay crane trolley, and the output terminal of the automatic phase sequence switching control circuit is connected to the power supply input terminal of the quay crane trolley. The braking mechanism control circuit includes an emergency control switch, an emergency control relay, a wheel clamp control relay, a brake control relay, and a cable reel control relay. The coils of the emergency control relay, the wheel clamp control relay, the brake control relay, and the cable reel control relay are connected in parallel and then in series with the emergency control switch. The emergency control relay, the wheel clamp control relay, the brake control relay, and the cable reel control relay are respectively connected to the main control circuit, the wheel clamp control circuit, the brake control circuit, and the cable reel control circuit of the quay crane trolley.

2. The emergency system for quay cranes according to claim 1, characterized in that: The main control circuit includes a PLC operating point, two reactor fuse detection points, a control closing point, a main control software interlock point, and multiple emergency stop switches connected in series. The normally open terminal of the emergency control relay is connected in parallel with the circuit formed by the PLC operating point, reactor fuse detection point, and main control software interlock point in the main control circuit of the quay crane.

3. The emergency system for quay cranes according to claim 1, characterized in that: The coil of the wheel clamp control relay is also connected in series with the wheel clamp emergency control switch. The normally closed terminal of the wheel clamp control relay is connected to the PLC control circuit, and the normally open terminal of the wheel clamp control relay is connected to the wheel clamp control circuit.

4. The emergency system for quay cranes according to claim 1, characterized in that: The coil of the brake control relay is also connected in series with the brake emergency control switch. The brake control circuit includes multiple converter preparation points, multiple frequency converter preparation points, and a gantry crane stop switch connected in series. The normally closed terminal of the brake control relay is connected to the PLC control circuit, and the normally open terminal of the brake control relay is connected in parallel with the circuit composed of multiple converter preparation points and multiple frequency converter preparation points.

5. The emergency system for quay cranes according to claim 1, characterized in that: The coil of the cable reel control relay is also connected in series with the cable reel emergency control switch. The normally closed terminal of the cable reel control relay is connected to the PLC control circuit, and the normally open terminal of the cable reel control relay is connected to the cable reel control circuit.

6. A quay crane trolley, characterized in that, Includes the emergency system for quay cranes as described in any one of claims 1-5.

Images