Hoist brake control system

Abstract

The utility model discloses a hoist brake control system, including brake, brake control valve, the outside control mouth of brake control valve spool is connected through shuttle valve and hoist motor A, B mouth pipeline, the export of brake control valve is equipped with the solenoid valve for controlling brake oil circuit on -off. In the realization brakeer automatic opening and closing condition, increase solenoid valve, increase brake control valve independent control, can determine whether brakeer opens according to the working condition, exempts from system back pressure influence.

Description

Technical Field

[0001] This utility model relates to a winch control device, and more particularly to a winch braking control system. Background Technology

[0002] The crane winch braking control system consists of a winch motor, a winch balance valve, a brake control valve, a winch brake, a reversing valve, and pipelines. To prevent the load from sinking due to internal leakage in the winch motor when the hoisting mechanism is stationary, cranes are equipped with a winch brake control system. The control logic is as follows: when the winch is in motion, the winch brake is activated before the winch motor rotates; when the winch stops, the winch brake is activated after the winch motor stops, locking the winch mechanism and preventing the load from sinking due to winch motor leakage. To ensure the timing of the winch brake activation and deactivation and the winch motor activation and deactivation, the pilot end of the winch brake control valve is mostly taken from the A / B port of the winch motor. For example, in a winch brake control system disclosed in invention patent application CN 105217508A, high-pressure oil from the motor load oil port passes through a shuttle valve. The shuttle valve is used to select the load high pressure. The high-pressure oil pushes the hydraulic control directional valve to switch, and the stable oil enters through the oil inlet P. The hydraulic control directional valve directly controls the opening of the winch brake.

[0003] When the winch motor drives the lifting or lowering, under normal circumstances, the return oil T-port pressure is low and the brake control valve cannot be opened. However, when the load is large, such as in the case of boom retraction under load, the boom retraction speed increases due to the load, the return oil flow increases, and the system return oil T-port pressure increases significantly. When the system back pressure is higher than the reversing pressure of the winch brake control valve, the winch brake control valve reverses, and the winch brake will open erroneously, causing the load to slide down. Utility Model Content

[0004] Purpose of the utility model: The purpose of this utility model is to provide a winch brake control system to prevent winch brake lock-up failure.

[0005] Technical solution: The present invention provides a winch braking control system, including a brake and a brake control valve. The external control port of the brake control valve core is connected to the A and B ports of the winch motor via a shuttle valve. The outlet of the brake control valve is provided with a solenoid valve for controlling the on / off state of the brake oil circuit.

[0006] Preferably, the solenoid valve has a first position and a second position, the first position being used to activate the brake control valve and the brake, and the second position being used to activate the brake and the oil tank.

[0007] Preferably, the winch braking control system further includes a telescopic cylinder reversing valve, and the external control port of the telescopic cylinder reversing valve is connected to a first pressure relay for controlling the switching of the solenoid valve.

[0008] Preferably, the winch braking control system further includes a winch motor reversing valve, and the external control port of the winch motor reversing valve is connected to a second pressure relay for controlling the switching of the solenoid valve.

[0009] Preferably, the inlet end of the brake control valve is connected via a pressure reducing valve and a shuttle valve.

[0010] Preferably, the external control port inlet of the brake control valve core and the brake control valve inlet are equipped with filters.

[0011] Preferably, in order to reduce fluctuations, a damping is provided between the brake control valve and the pressure reducing valve.

[0012] Beneficial effects: Compared with the prior art, the present invention has the following advantages: 1. Preventing the locking failure of the winch brake: When the brake is automatically opened and closed, the addition of a solenoid valve can determine whether the brake is open according to the working conditions, eliminating the influence of system back pressure; 2. The reversing pressure setting value of the brake reversing valve can be lower than the starting pressure of the winch motor, avoiding pressure shock caused by poor component consistency, where the winch brake opens later than the winch motor starts. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the winch braking control system of this utility model. Detailed Implementation

[0014] The technical solution of this utility model will be further described below with reference to the accompanying drawings.

[0015] Example 1: As Figure 1 As shown, the winch braking control system mainly consists of a brake 7 and a brake control valve 1. The inlet of brake control valve 1 has a shuttle valve, which is connected to the A and B ports of the winch motor to select high-pressure hydraulic fluid. The external control port of the brake control valve 1 is connected to the outlet of the shuttle valve. The high-pressure hydraulic fluid selected by the shuttle valve pushes the valve core of brake control valve 1 to change direction. The outlet of brake control valve 1 is connected to a solenoid valve 6, which controls the opening and closing of the brake oil circuit. Specifically, solenoid valve 6 has a first position (left in the figure) and a second position (right in the figure). The first position is used to connect brake control valve 1 and brake 7, and the second position is used to connect brake 7 and the oil tank, locking the winch motor. The inlet of brake control valve 1 is connected to the shuttle valve through a pressure reducing valve, a damper, and a pressure reducing valve, converting the high-pressure hydraulic fluid from the shuttle valve into hydraulic fluid at a set pressure, stabilizing the pressure, and thus opening brake 7. The outlet of the shuttle valve has a filter, and the external control port inlet of brake control valve 1 and the inlet of brake control valve are both connected to the filter through this filter and the shuttle valve.

[0016] By setting up solenoid valve 6, which is independently controlled, the brake 7 and the outlet of brake control valve 1 can be disconnected according to the working conditions, so that the brake 7 is not affected by back pressure.

[0017] Example 2: Based on Example 1, this example can also be modified as follows: The winch braking control system is electrically connected to the telescopic cylinder reversing valve 4 and the winch motor reversing valve 3. The solenoid valve 6 is determined to be open based on the signals from the telescopic cylinder reversing valve and the winch motor reversing valve, thereby simplifying the control. Specifically:

[0018] The external control port Ya2 of the telescopic cylinder reversing valve 4 and the external control port Ya1 of the hoisting motor reversing valve 3 are equipped with pressure relay 9. Pressure relay 9 is connected to the main control system. Solenoid valve 6 is connected to the main control system. 1. When the hoisting is raised, solenoid valve 6 does not participate in the control.

[0019] 2. With the winch stationary and the telescopic cylinder retracting: Pushing the telescopic pilot handle increases the output pressure oil of Ya2 to the set pressure of the telescopic linkage pressure relay 9. The pressure relay 9 then sends an electrical signal to the solenoid valve 6, which switches to the right position. As the opening of the pilot handle increases, the output pressure oil of Ya1 increases to the switching pressure of the telescopic three-position four-way directional valve 4. The telescopic three-position four-way directional valve 4 switches to the left position. The pressure oil at port P1 pushes the telescopic balance valve 5 to the left position, connecting it to the small chamber of the telescopic cylinder, thus retracting the telescopic cylinder. The large chamber of the telescopic cylinder connects to T1 through the left position of the telescopic three-position four-way directional valve 4 for oil return and telescopic retraction. At this time, the rod chamber of the winch brake 7 connects to the oil tank through the right position of the solenoid valve 6. The magnitude of the oil return pressure T1 will not cause the winch brake 7 to open.

[0020] 3. Combined working condition of telescopic cylinder retraction + hoisting: The logic of telescopic retraction is the same as that in 2 above. When telescopic retraction is performed, the pressure relay 9 sends an electrical signal to the solenoid valve 6. The solenoid valve 6 is energized and reverses to the right position.

[0021] Hoisting operation: When the hoisting pilot handle is pushed, the output pressure oil of Ya1 increases to the set pressure of the hoisting linkage pressure relay 8. Pressure relay 8 sends an electrical signal to solenoid valve 6. When pressure relays 8 and 9 send electrical signals simultaneously, solenoid valve 6 is de-energized, meaning pressure relay 8 has higher priority than pressure relay 9. Solenoid valve 6 is de-energized and reverses to the left position. As the opening of the pilot handle increases, the output pressure oil of Ya1 increases to the reversing pressure of the hoisting three-position four-way directional valve 3. When the hoisting three-position four-way directional valve 3 is switched to the left position, the pressure oil at port P1 is connected to port B1 of the brake control valve 1 and to the hoisting motor B. Since the switching pressure of the HV directional valve is less than the starting pressure of the hoisting motor, the pressure oil at port B1 first pushes the HV directional valve to switch to the left position. After the HV directional valve switches, the pressure oil at port B1 is connected to the rod chamber of the hoisting brake 7, pushing the hoisting brake to open. After the hoisting brake 7 is opened, the pressure at port B1 continues to increase to the starting pressure of the hoisting motor, and the compound hoisting starts.

Claims

1. A hoist braking control system, characterized in that, Includes a brake (7) and a brake control valve (1). The outer control port of the brake control valve (1) is connected to the A and B ports of the hoisting motor via a shuttle valve. The outlet of the brake control valve (1) is equipped with a solenoid valve (6) for controlling the oil circuit of the brake.

2. The winch braking control system according to claim 1, characterized in that, The solenoid valve (6) has a first position and a second position. The first position is used to connect the brake control valve (1) and the brake (7), and the second position is used to connect the brake (7) and the oil tank.

3. The hoist braking control system according to claim 1, characterized in that, The winch braking control system also includes a telescopic cylinder reversing valve (4), and the external control port of the telescopic cylinder reversing valve (4) is connected to a first pressure relay (9) for controlling the switching of the solenoid valve.

4. The hoist braking control system according to claim 1, characterized in that, The winch braking control system also includes a winch motor reversing valve (3), and the external control port of the winch motor reversing valve (3) is connected to a second pressure relay (8) for controlling the switching of the solenoid valve.

5. The hoist braking control system according to claim 1, characterized in that, The inlet of the brake control valve (1) is connected to a pressure reducing valve and a shuttle valve.

6. The hoist braking control system according to claim 1, characterized in that, The brake control valve (1) has filters at the external control port inlet and the brake control valve inlet.

7. The winch braking control system according to claim 5, characterized in that, A damper is provided between the brake control valve (1) and the pressure reducing valve.

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