A safety control system for crane travel

Abstract

The present invention is directed to a traveling trolley of a cantilever crane. In the process of starting and stopping, there will be inertia. In order to avoid too much inertia and enable the trolley to start or stop smoothly, a safety control system applied to the traveling of the crane is designed, which is suitable for the traveling trolley of the cantilever crane, including: a proximity switch circuit of a limit group, a button box circuit, a contactor control circuit, and a dual-speed motor control circuit; a forward limit group and a backward limit group are arranged on the traveling trolley, and a limit block is arranged in the frame of the cantilever crane; the peripheral circuits of the forward limit group and the backward limit group are the proximity switch circuit of the limit group; the proximity switch circuit and the button box circuit of the limit group are connected to the contactor control circuit, and the dual-speed motor control circuit is controlled by the contactor control circuit, and the dual-speed motor control circuit is used to control the dual-speed motor to switch between high-speed gear, low-speed gear and stop.

Description

Technical Field

[0001] The utility model relates to the field of cranes, in particular to a safety control system used for traveling of cranes. Background Art

[0002] Cantilever cranes mainly use the side width (pitch) of the boom to rotate around the vertical axis to lift and lower goods. They are flexible to use and meet the requirements of loading and unloading. They are available in fixed, mobile and floating types. Fixed cantilever cranes are directly installed on the piers of docks or warehouses and can only work in situ. Some of them can only pitch but not rotate, and the walking trolley on the cantilever is used to move the lifted goods horizontally to meet the needs of moving goods.

[0003] Since the trolley usually carries heavy goods, it will generate inertia during the movement, especially during the start and stop process. In order to avoid too much inertia and make the trolley start or stop smoothly, a safety control system needs to be designed to make the trolley run smoothly. Summary of the invention

[0004] The utility model is for a traveling trolley of a cantilever crane. In the process of starting and stopping, it will carry inertia. In order to avoid too much inertia and enable the trolley to start or stop smoothly, a safety control system and control method for crane travel are designed. When the trolley reaches the travel boundary, it is first decelerated to low speed operation and then stops.

[0005] The entire trolley travel mechanism is mainly composed of the trolley (fixed mechanism), motor (driving mechanism), travel reducer, travel roller, guide wheel, limit block, mechanical block, and travel track. The rest of the lifting parts are not introduced. The travel reducer is driven by the motor, and the travel reducer drives the trolley forward or backward on the travel track. This is the conventional driving method of the trolley.

[0006] In addition to manual stopping, the existing trolley driving method uses a combination of limit blocks and mechanical blocks. When the trolley reaches the edge, the limit blocks are triggered to cut off the power of the trolley to avoid rushing out of the edge area, and the mechanical blocks are used to eliminate inertia. However, this method does not meet safety requirements. For this reason, the present invention proposes a safety control system for crane travel, which is suitable for the travel trolley of a cantilever crane, including: a proximity switch circuit of a limit group, a button box circuit, a contactor control circuit, and a dual-speed motor control circuit.

[0007] The trolley uses a dual-speed motor, and is provided with a forward limit group and a backward limit group. A limit block is provided in the frame of the cantilever crane to cooperate with the forward limit group and the backward limit group. The forward limit group and the backward limit group both include: a deceleration limit proximity switch and a travel limit proximity switch;

[0008] The peripheral circuits of the forward limit group and the backward limit group are the proximity switch circuits of the limit groups;

[0009] The proximity switch circuit and button box circuit of the limit group are connected to the contactor control circuit, and the dual-speed motor control circuit is controlled by the contactor control circuit.

[0010] The dual-speed motor control circuit is used to control the dual-speed motor to switch between high-speed gear, low-speed gear and stop.

[0011] The dual-speed motor control circuit comprises:

[0012] Two-speed motor M3, motor forward contactor 2K1, motor reverse contactor 2K2, slow gear contactor 2K3, fast gear contactors 2K4 and 2k5; the contactors are all controlled by buttons;

[0013] Powered by AC380V power supply, it is connected in sequence to the circuit breaker FQ1, the motor forward contactor 2K1, the slow gear contactor 2K3, the thermal relay 2FR1, and the first input terminal of the dual-speed motor M3;

[0014] The reversing circuit is connected in sequence to the circuit breaker FQ1, the motor reversing contactor 2K2, the slow gear contactor 2K3, the thermal relay 2FR1, and the first input terminal of the dual-speed motor M3;

[0015] The fast gear contactor 2k5 and the fast gear contactor 2K4 are arranged according to the fast gear circuit of the dual-speed motor;

[0016] A thermal relay 2FR2 is provided between the contactor 2k4 and the dual-speed motor M3;

[0017] The built-in thermistor of the dual-speed motor M3 is connected to the control terminal of the thermal relay KT3.

[0018] The dual-speed motor control circuit also includes a step-down output circuit; the step-down output circuit includes: a transformer T1, the input end of the transformer T1 is powered by an AC380V power supply, the first output end outputs an AC26V power supply, and the second output end outputs an AC220V power supply; the AC220V power supply is also connected to a step-down module to output a 24V DC power supply;

[0019] The button box circuit is powered by an AC26V power supply; the button box circuit includes a slow forward button 3S1, a slow reverse button 4S1, a fast forward button 3S2, and a fast reverse button 4S2;

[0020] The slow forward button 3S1 is connected in series with the normally closed contactor KA3 and the control end of the contactor KA2;

[0021] The slow reverse button 4S1 is connected in series with the normally closed contactor KA2 and the control end of the contactor KA3; the normally closed contactor KA2 and the normally closed contactor KA3 are interlocked;

[0022] The fast forward button 3S2 is connected to the time relay 2K6 and the time relay 2K8, and the fast reverse button 4S2 is connected to the time relay 2K7 and the time relay 2K9; the time relay 2K6 and the time relay 2K8 are connected in parallel; the time relay 2K7 and the time relay 2K9 are connected in parallel.

[0023] The proximity switch circuit of the limit group includes:

[0024] Forward deceleration limit proximity switch SQ3, forward travel limit proximity switch SQ1, reverse deceleration limit proximity switch SQ4, reverse travel limit proximity switch SQ2;

[0025] Forward deceleration limit proximity switch SQ3, forward travel limit proximity switch SQ1, reverse deceleration limit proximity switch SQ4, reverse travel limit proximity switch SQ2; all powered by a low-voltage DC power supply;

[0026] The forward travel limit proximity switch SQ1 is connected in series with the control end of the contactor KA4;

[0027] The backward stroke limit proximity switch SQ2 is connected in series with the control end of the contactor KA5;

[0028] The forward deceleration limit proximity switch SQ3 is connected in series with the control end of the contactor KA6;

[0029] The reverse deceleration limit proximity switch SQ4 is connected in series with the contactor KA7 control end.

[0030] The contactor control circuit includes: an intermediate control circuit, a forward control circuit, a backward control circuit, a slow control circuit and a fast control circuit;

[0031] The forward control circuit is connected in series with contactor KA2, normally closed contactor KA4, normally closed contactor 2K2, contactor 2K1 control end, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0032] The forward control circuit includes: time relay 2K6, which is connected in parallel with contactor KA2;

[0033] The backward control circuit is connected in series with contactor KA3, normally closed contactor KA4, normally closed contactor 2K1, control end of contactor 2K2, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0034] The backward control circuit includes: time relay 2K7, which is connected in parallel with contactor KA2;

[0035] The slow control circuit is connected in series with contactor 2K1, normally closed contactor KA9, normally closed contactor 2K4, normally closed contactor 2K5, contactor 2K3 control terminal, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0036] The slow speed control circuit includes: contactor 2K2, which is connected in parallel with contactor 2K1;

[0037] The fast control circuit is connected in series with contactor 2K1, contactor KA9, normally closed contactor 2K3, control end of contactor 2K4, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0038] The fast control loop includes: contactor 2K2, contactor 2K5 control end; contactor 2K2 is connected in parallel with contactor 2K1, and contactor 2K5 control end is connected in parallel with contactor 2K4 control end;

[0039] The intermediate control circuit is connected in series with the time relay 2K8, the normally closed contactor KA6, the normally closed contactor KA7, and the control end of the contactor KA9;

[0040] The intermediate control loop includes: time relay 2K9, time relay 2K8 and time relay 2K9 are connected in parallel.

[0041] Preferably, the length of the limit stopper is greater than or equal to 50 cm;

[0042] The distance x between the deceleration limit proximity switch and the travel limit proximity switch in the limit group satisfies: 35cm>=x, x>=25cm.

[0043] The beneficial effects of the utility model are as follows: the control of the logic circuit formed by the trigger is more reliable and stable, and the inertia of the trolley is cleverly eliminated by first slowing down and then stopping, thereby avoiding accidents caused by the inertia of the driving trolley. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The coordination diagram of the traveling trolley knot and the block;

[0045] Figure 2 Dual speed motor control circuit diagram;

[0046] Figure 3 Button box circuit diagram;

[0047] Figure 4 The proximity switch circuit diagram of the limit group;

[0048] Figure 5 Control circuit diagram;

[0049] Figure 6Thermistor wiring diagram;

[0050] Figure 7 Motor standby heating circuit diagram;

[0051] Figure 8 Rectification circuit diagram;

[0052] In the figure: 1. Reverse deceleration limit proximity switch, 2. Reverse travel limit proximity switch, 3. Dual-speed motor, 4. Forward travel limit proximity switch, 5. Forward deceleration limit proximity switch, 6. Mechanical stopper, 7. Travel trolley, 8. Travel reducer, 9. Travel roller, 10. Guide wheel, 11. Limit stopper, 12. Mechanical limit, 13. Travel track. DETAILED DESCRIPTION

[0053] The technical solution of the utility model is further described in detail below through specific embodiments and in conjunction with the accompanying drawings. Example

[0054] like Figure 1 As shown, the entire trolley travel mechanism is mainly composed of a travel trolley 7 (fixed mechanism), a dual-speed motor 3 (driving mechanism), a travel reducer 8, a travel roller 9, a guide wheel 10, a limit block 11, a mechanical block 6, a mechanical limit 12, and a travel track 13. The rest of the lifting parts are not introduced. The trigger mechanism of the mechanical limit 12 mechanism uses soft rubber (the mechanical block 6 is wrapped with soft rubber), which can buffer the impact force of the trolley. It is set after the electric limit and installed on the trolley. When the electric limit fails, the trolley can be stopped.

[0055] A safety control system for crane travel, suitable for the travel trolley of a cantilever crane, comprising: a proximity switch circuit of a limit group, a button box circuit, a contactor control circuit, and a dual-speed motor control circuit;

[0056] The trolley uses a dual-speed motor, and is provided with a forward limit group and a backward limit group. A limit block is provided in the frame of the cantilever crane to cooperate with the forward limit group and the backward limit group. The forward limit group and the backward limit group both include: a deceleration limit proximity switch and a travel limit proximity switch;

[0057] The peripheral circuits of the forward limit group and the backward limit group are the proximity switch circuits of the limit groups;

[0058] The proximity switch circuit and button box circuit of the limit group are connected to the contactor control circuit, and the dual-speed motor control circuit is controlled by the contactor control circuit.

[0059] The dual-speed motor control circuit is used to control the dual-speed motor to switch between high-speed gear, low-speed gear and stop.

[0060] like Figure 2The dual-speed motor control circuit shown is powered by AC380V power supply, including: dual-speed motor M3, motor forward contactor 2K1, motor reverse contactor 2K2, slow gear contactor 2K3, fast gear contactors 2K4 and 2k5; the contactors are all controlled by buttons to be attracted;

[0061] Powered by AC380V power supply, it is connected in sequence to the circuit breaker FQ1, the motor forward contactor 2K1, the slow gear contactor 2K3, the thermal relay 2FR1, and the first input terminal of the dual-speed motor M3;

[0062] The reversing circuit is connected in sequence to the circuit breaker FQ1, the motor reversing contactor 2K2, the slow gear contactor 2K3, the thermal relay 2FR1, and the first input terminal of the dual-speed motor M3;

[0063] The fast gear contactor 2k5 and the fast gear contactor 2K4 are arranged according to the fast gear circuit of the dual-speed motor;

[0064] A thermal relay 2FR2 is provided between the contactor 2k4 and the dual-speed motor M3;

[0065] like Figure 6 The built-in thermistor of the dual-speed motor M3 shown is connected to the control end of the thermal relay KT3 through ports TH31 and TH32.

[0066] like Figure 7 As shown, ports 31 and 32 of the dual-speed motor M3 are used to connect to the motor heating power supply. Ports 31 and 32 contain built-in heaters for the dual-speed motor M3.

[0067] like Figure 1 The proximity switch circuit of the limit group shown includes: a forward deceleration limit proximity switch 5, a forward travel limit proximity switch 4, a reverse deceleration limit proximity switch 1, and a reverse travel limit proximity switch 2.

[0068] The electrical symbols for these switches are as follows Figure 4 As shown: forward deceleration limit proximity switch SQ3, forward travel limit proximity switch SQ1, reverse deceleration limit proximity switch SQ4, reverse travel limit proximity switch SQ2;

[0069] Forward deceleration limit proximity switch SQ3, forward travel limit proximity switch SQ1, reverse deceleration limit proximity switch SQ4, reverse travel limit proximity switch SQ2; all powered by a low-voltage DC power supply;

[0070] The forward travel limit proximity switch SQ1 is connected in series with the control end of the contactor KA4;

[0071] The backward stroke limit proximity switch SQ2 is connected in series with the control end of the contactor KA5;

[0072] The forward deceleration limit proximity switch SQ3 is connected in series with the control end of the contactor KA6;

[0073] The reverse deceleration limit proximity switch SQ4 is connected in series with the control end of the contactor KA7.

[0074] like Figure 8 As shown, the dual-speed motor control circuit also includes a step-down output circuit; the step-down output circuit includes: a transformer T1, the input end of the transformer T1 is powered by an AC380V power supply, the first output end outputs an AC26V power supply, and the second output end outputs an AC220V power supply; the AC220V power supply is also connected to a step-down module to output a 24V DC power supply;

[0075] The button box circuit is powered by an AC26V power supply; the button box circuit includes a slow forward button 3S1, a slow reverse button 4S1, a fast forward button 3S2, and a fast reverse button 4S2;

[0076] The slow forward button 3S1 is connected in series with the normally closed contactor KA3 and the control end of the contactor KA2;

[0077] The slow reverse button 4S1 is connected in series with the normally closed contactor KA2 and the control end of the contactor KA3; the normally closed contactor KA2 and the normally closed contactor KA3 are interlocked;

[0078] The fast forward button 3S2 is connected to the time relay 2K6 and the time relay 2K8, and the fast reverse button 4S2 is connected to the time relay 2K7 and the time relay 2K9; the time relay 2K6 and the time relay 2K8 are connected in parallel; the time relay 2K7 and the time relay 2K9 are connected in parallel.

[0079] like Figure 3 and Figure 5 The contactor control circuit shown includes: an intermediate control circuit, a forward control circuit, a reverse control circuit, a slow control circuit and a fast control circuit;

[0080] The forward control circuit is connected in series with contactor KA2, normally closed contactor KA4, normally closed contactor 2K2, contactor 2K1 control end, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0081] The forward control circuit includes: time relay 2K6, which is connected in parallel with contactor KA2;

[0082] The backward control circuit is connected in series with contactor KA3, normally closed contactor KA4, normally closed contactor 2K1, control end of contactor 2K2, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0083] The backward control circuit includes: time relay 2K7, which is connected in parallel with contactor KA2;

[0084] The slow control circuit is connected in series with contactor 2K1, normally closed contactor KA9, normally closed contactor 2K4, normally closed contactor 2K5, contactor 2K3 control terminal, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0085] The slow speed control circuit includes: contactor 2K2, which is connected in parallel with contactor 2K1;

[0086] The fast control circuit is connected in series with contactor 2K1, contactor KA9, normally closed contactor 2K3, control end of contactor 2K4, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3;

[0087] The fast control loop includes: contactor 2K2, contactor 2K5 control end; contactor 2K2 is connected in parallel with contactor 2K1, and contactor 2K5 control end is connected in parallel with contactor 2K4 control end;

[0088] The intermediate control circuit is connected in series with the time relay 2K8, the normally closed contactor KA6, the normally closed contactor KA7, and the control end of the contactor KA9;

[0089] The intermediate control loop includes: time relay 2K9, time relay 2K8 and time relay 2K9 are connected in parallel.

[0090] The length of the limit stop is 51 cm.

[0091] The distance between the deceleration limit proximity switch and the travel limit proximity switch in the limit group is 30cm.

[0092] The contactors (2K1 and 2K2) in the main circuit control the forward and reverse rotation of the motor, that is, the forward and backward rotation of the trolley. The contactor (2K3) is slow, and the contactors (2K4 and 2K5) are fast. Slow speed is direct start. After pressing the button, the contactors will be attracted in sequence: when rotating forward, contactor 2K1 will act first, then 2K3 will act; when reversing, contactor 2K2 will act, then 2K3 will act. Thereby ensuring the stability of slow speed; when starting quickly, press the fast button, and the contactors will be attracted in sequence: when rotating forward, contactors 2K1 and 2K3 will act first, then 2K3 will be disconnected, 2K4 and 2K5 will act, so that it can run quickly; when reversing, contactors 2K2 and 2K3 will act, then 2K3 will be disconnected, 2K4 and 2K5 will act, so that it can run quickly. The power-on delay relay and the power-off delay relay control the sequence of closure. First, the slow contactor is closed, and the power-on delay of 1S (adjustable time) is triggered, the fast contactors 2K4 and 2K5 are closed, and the slow contactor 2K3 is disconnected, so that it runs quickly. When it stops, release the fast button, the power-off delay is triggered, the fast contactors 2K4 and 2K5 are disconnected, and the slow contactor 2K3 is closed. After the trolley runs slowly for 1s (adjustable time), the 2K1 or 2k2 contactor is disconnected, and the 2K3 contactor is disconnected, and the trolley stops running, so that the impact of the trolley is minimized. The motor has thermal relay protection and thermistor protection to prevent overload or long operation time.

[0093] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A safety control system for crane travel, suitable for a traveling trolley of a cantilever crane, characterized in that: include: The proximity switch circuit, button box circuit, contactor control circuit, and dual-speed motor control circuit of the limit group; The trolley uses a dual-speed motor, and is provided with a forward limit group and a backward limit group. A limit block is provided in the frame of the cantilever crane to cooperate with the forward limit group and the backward limit group. The forward limit group and the backward limit group both include: a deceleration limit proximity switch and a travel limit proximity switch; The peripheral circuits of the forward limit group and the backward limit group are the proximity switch circuits of the limit groups; The proximity switch circuit and button box circuit of the limit group are connected to the contactor control circuit, and the dual-speed motor control circuit is controlled by the contactor control circuit. The dual-speed motor control circuit is used to control the dual-speed motor to switch between high-speed gear, low-speed gear and stop.

2. A safety control system for crane travel according to claim 1, characterized in that: The dual-speed motor control circuit comprises: Two-speed motor M3, motor forward contactor 2K1, motor reverse contactor 2K2, slow gear contactor 2K3, fast gear contactors 2K4 and 2k5; the contactors are all controlled by buttons; Powered by AC380V power supply, it is connected in sequence to the circuit breaker FQ1, the motor forward contactor 2K1, the slow gear contactor 2K3, the thermal relay 2FR1, and the first input terminal of the dual-speed motor M3; The reversing circuit is connected in sequence to the circuit breaker FQ1, the motor reversing contactor 2K2, the slow gear contactor 2K3, the thermal relay 2FR1, and the first input terminal of the dual-speed motor M3; The fast gear contactor 2k5 and the fast gear contactor 2K4 are arranged according to the fast gear circuit of the dual-speed motor; A thermal relay 2FR2 is provided between the contactor 2k4 and the dual-speed motor M3; The built-in thermistor of the dual-speed motor M3 is connected to the control terminal of the thermal relay KT3.

3. A safety control system for crane travel according to claim 2, characterized in that: The proximity switch circuit of the limit group includes: Forward deceleration limit proximity switch SQ3, forward travel limit proximity switch SQ1, reverse deceleration limit proximity switch SQ4, reverse travel limit proximity switch SQ2; all powered by a low-voltage DC power supply; The forward travel limit proximity switch SQ1 is connected in series with the control end of the contactor KA4; The backward stroke limit proximity switch SQ2 is connected in series with the control end of the contactor KA5; The forward deceleration limit proximity switch SQ3 is connected in series with the control end of the contactor KA6; The reverse deceleration limit proximity switch SQ4 is connected in series with the contactor KA7 control end.

4. A safety control system for crane travel according to claim 3, characterized in that: The dual-speed motor control circuit also includes a step-down output circuit; the step-down output circuit includes: a transformer T1, the input end of the transformer T1 is powered by an AC380V power supply, the first output end outputs an AC26V power supply, and the second output end outputs an AC220V power supply; the AC220V power supply is also connected to a step-down module to output a 24V DC power supply; The button box circuit is powered by an AC26V power supply; the button box circuit includes a slow forward button 3S1, a slow reverse button 4S1, a fast forward button 3S2, and a fast reverse button 4S2; The slow forward button 3S1 is connected in series with the normally closed contactor KA3 and the control end of the contactor KA2; The slow reverse button 4S1 is connected in series with the normally closed contactor KA2 and the control end of the contactor KA3; the normally closed contactor KA2 and the normally closed contactor KA3 are interlocked; The fast forward button 3S2 is connected to the time relay 2K6 and the time relay 2K8, and the fast reverse button 4S2 is connected to the time relay 2K7 and the time relay 2K9; the time relay 2K6 and the time relay 2K8 are connected in parallel; the time relay 2K7 and the time relay 2K9 are connected in parallel.

5. A safety control system for crane travel according to claim 4, characterized in that: The contactor control circuit includes: an intermediate control circuit, a forward control circuit, a backward control circuit, a slow control circuit and a fast control circuit; The forward control circuit is connected in series with contactor KA2, normally closed contactor KA4, normally closed contactor 2K2, contactor 2K1 control end, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3; The forward control circuit includes: time relay 2K6, which is connected in parallel with contactor KA2; The reverse control circuit is connected in series with contactor KA3, normally closed contactor KA4, normally closed contactor 2K1, control end of contactor 2K2, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3; The backward control circuit includes: time relay 2K7, which is connected in parallel with contactor KA2; The slow control circuit is connected in series with contactor 2K1, normally closed contactor KA9, normally closed contactor 2K4, normally closed contactor 2K5, contactor 2K3 control terminal, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3; The slow speed control circuit includes: contactor 2K2, which is connected in parallel with contactor 2K1; The fast control circuit is connected in series with contactor 2K1, contactor KA9, normally closed contactor 2K3, control end of contactor 2K4, thermal relay 2FR1, thermal relay 2FR2, and thermal contactor KT3; The fast control loop includes: contactor 2K2, contactor 2K5 control end; contactor 2K2 is connected in parallel with contactor 2K1, and contactor 2K5 control end is connected in parallel with contactor 2K4 control end; The intermediate control circuit is connected in series with the time relay 2K8, the normally closed contactor KA6, the normally closed contactor KA7, and the control end of the contactor KA9; The intermediate control loop includes: time relay 2K9, time relay 2K8 and time relay 2K9 are connected in parallel.

6. The safety control system for crane travel according to claim 1, characterized in that: The length of the limit stopper is >= 50cm; The distance x between the deceleration limit proximity switch and the travel limit proximity switch in the limit group satisfies: 35cm>=x, x>=25cm.

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