A crane hoist control hydraulic valve

Abstract

This invention discloses a hydraulic control valve for crane winches, comprising a valve body. The valve body contains a valve stem for controlling the opening and closing of oil ports. The left and right ends of the valve stem are subjected to hydraulic pressure corresponding to the angle of the winch handle, used to adjust the operating conditions. The valve stem has a U-shaped throttling groove along its cylindrical surface at the fourth throttling orifice. The valve body also has an annular groove at the fourth throttling orifice. A relief valve is installed on the valve body. The annular groove and the relief valve inlet are connected through an oil passage on the valve body. The cavity T is connected to the relief valve outlet. The valve stem has an arc-shaped throttling groove at the third throttling orifice. When the valve stem is in the neutral position, the third throttling orifice is open. This invention proposes a hydraulic valve for crane winches that can improve the micro-vibration and tremors during winch lifting. When the winch motor rotates at low speed, the motor return oil first passes through the relief valve. The back pressure provided by the relief valve can stabilize the motor speed at low speeds, avoiding winch jerking and vibration.

Description

Technical Field

[0001] This invention belongs to the technical field of cranes, and in particular relates to a hydraulic valve for controlling crane winches. Background Technology

[0002] In a crane hoisting system, the multi-way valve's hoisting directional valve (hereinafter referred to as the hydraulic valve) controls the hoisting's lifting and lowering, and its structural principle directly affects the controllability of the hoisting operation. In the crane hoisting hydraulic system, the hydraulic pump provides high-pressure oil to the system; the hoisting motor converts hydraulic energy into mechanical energy, driving the hoisting reducer to rotate; the hydraulic valve controls the hoisting's lifting and lowering by controlling the direction of oil inlet and outlet to the motor.

[0003] Problems with existing winch control hydraulic valves: When a crane winch system is working, it not only needs high operating efficiency to complete the winch operation efficiently, but also excellent micro-motion performance to precisely control the load to reach the target position. When the winch motor runs at high speed, the speed is stable; however, when the winch motor runs at low speed, the speed is uneven, leading to winch vibration during micro-motion. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a crane winch control hydraulic valve with low return oil back pressure and low energy loss.

[0005] Technical Solution: The crane winch control hydraulic valve of the present invention includes a valve body, wherein a valve stem is provided in the valve body for controlling the opening and closing of the oil port. The left and right end faces of the valve stem are subjected to hydraulic pressure corresponding to the angle of the winch handle for adjusting the working conditions. The hydraulic valve stem has a U-shaped throttling groove along the cylindrical surface at the fourth throttling port, and the valve body has an annular groove at the fourth throttling port. An overflow valve is installed on the valve body. The annular groove and the oil inlet of the overflow valve are connected through an oil passage on the valve body. The cavity T is connected to the oil outlet of the overflow valve. The valve stem has an arc-shaped throttling groove at the third throttling port. When the valve stem is in the neutral position, the third throttling port is open.

[0006] The valve body is provided with a second throttling orifice, which connects cavity P and cavity P'. The output end of cavity P' is connected to a pressure compensator.

[0007] The pressure compensator is connected to the cavity A' through the fifth throttling orifice, and the output end of the cavity A' is connected to the cavity A through the first throttling orifice.

[0008] The pressure oil is input into the balance valve at the output end of the cavity A, and the balance valve drives the winch motor to rotate.

[0009] The return oil from the hoist motor enters the hydraulic valve cavity B through the hydraulic pipeline. The oil in cavity B passes through the U-shaped throttling groove and enters the annular groove on the valve body. The annular groove is connected to the oil inlet of the overflow valve.

[0010] When the hydraulic pressure of the return oil in the cavity B increases, the overflow valve is opened, and the return oil returns through the outlet oil passage of the overflow valve. At this time, the valve stem moves to the left by a displacement of X1.

[0011] The U-shaped throttling groove is provided in at least four sets.

[0012] When the valve stem displacement is less than X1, the hoisting is in the micro-motion range. At this time, the return oil of the hoisting motor passes through the overflow valve, and the overflow valve provides back pressure for the hoisting motor to rotate at low speed.

[0013] When the valve stem displacement is greater than X1, the fourth throttle port opens, the speed of the winch motor increases and stabilizes, and the winch motor returns oil through the throttle port. When the oil pressure loss through the throttle port is low, the back pressure of the winch motor's return oil is small. When the fourth throttle port is opened to its maximum, the return oil flow rate of the winch motor continues to increase.

[0014] The relief valve is a cartridge-type relief valve, which can be replaced by a cartridge-type check valve.

[0015] Beneficial Effects: Compared with the prior art, this invention has the following significant advancements: This invention proposes a hydraulic valve for use in crane winches, which can improve the micro-vibration and shaking during winch lifting. When the winch motor rotates at low speed, the motor return oil first returns through the relief valve. The back pressure provided by the relief valve can stabilize the motor speed at low speeds, avoiding winch jerking and vibration. When the winch lifts at high speed, the winch motor return oil returns through the open throttle orifice, resulting in low back pressure and minimal energy loss. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the hoist control valve structure of the present invention;

[0017] Figure 2 This is a partial enlarged view of the hoist control valve;

[0018] Figure 3 This is a graph showing the change in back pressure of the hoisting return oil as a function of valve stem displacement. Detailed Implementation

[0019] like Figures 1-3As shown, the present invention includes a valve body 1, within which a valve stem 2 is provided for controlling the opening and closing of the oil port. The left and right end faces of the valve stem 2 are subjected to hydraulic pressure corresponding to the angle of the winch handle, used to adjust the working conditions. The hydraulic valve stem 2 has a U-shaped throttling groove along its cylindrical surface at the fourth throttling port 13. The valve body 1 has an annular groove 10 at the fourth throttling port 13. A relief valve 11 is installed on the valve body. The annular groove 10 and the oil inlet of the relief valve 11 are connected through an oil passage on the valve body 1. The cavity T112 is connected to the oil outlet of the relief valve 11. The valve stem 2 has an arc-shaped throttling groove at the third throttling port 9. When the valve stem 2 is in the neutral position, the third throttling port 9 is open. The valve body 1 has a second throttling port 6, which connects to cavities P5 and P'7. The output end of cavity P'7 is connected to a pressure compensator 16. Pressure compensator 16 is connected to cavity A'4 via fifth throttling port 15, and the output end of cavity A'4 is connected to cavity A17 via first throttling port 3. The output end of cavity A17 inputs pressure oil into balance valve 18, which drives winch motor 19 to rotate. The return oil from winch motor 19 enters hydraulic valve cavity B14 through hydraulic pipeline, and the oil in cavity B14 enters annular groove 10 on valve body 1 through U-shaped throttling groove. Annular groove 10 is connected to the oil inlet of relief valve 11.

[0020] Working principle: The hydraulic valve stem 2 has four "U"-shaped throttling grooves along its cylindrical surface at the fourth throttling orifice 13. The valve body 1 has an annular groove 10 at the fourth throttling orifice 13. An overflow valve 11 is installed on the valve body. The annular groove 10 and the oil inlet of the overflow valve 11 are connected through an oil passage on the valve body 1. The cavity T112 is connected to the oil outlet of the overflow valve 11. The valve stem 2 has an arc-shaped throttling groove at the third throttling orifice 9. When the valve stem 2 is in the neutral position, the third throttling orifice 9 is open. When the winch handle is operated for winch lifting and micro-movement lifting operations, the right end face of the valve stem 2 is subjected to hydraulic pressure corresponding to the handle tilt angle. The hydraulic pressure overcomes the spring force at the left end of the hydraulic valve, pushing the valve stem 2 to the left. The leftward movement of the valve stem 2 opens the second throttling orifice 6, and the high-pressure oil in the cavity P5 enters the cavity P'7 through the second throttling orifice 6. High-pressure oil in cavity P' pushes the valve core of pressure compensator 16 upward, opening the fifth throttle port 15. Oil then enters cavity A'4 through the fifth throttle port 15, and subsequently flows into cavity A17 through the first throttle port 3. Pressure oil at port A of hydraulic valve drives the winch motor 19 to rotate via the balance valve 18. Return oil from the motor enters hydraulic valve cavity B14 through the hydraulic pipeline. At this time, the displacement of valve stem 2 is less than X1, and the fourth throttle port 13 between valve stem 2 and cavity T112 is not yet open. Oil in cavity B enters the annular groove 10 on the valve body through the "U"-shaped throttling groove, which connects to the inlet of relief valve 11. The return hydraulic pressure increases, opening relief valve 11. Return oil returns through the outlet oil passage of relief valve 11, meaning the relief valve provides back pressure for the return oil from winch motor 19. As the winch handle tilt angle continues to increase, valve stem 2 continues to move to the left under greater hydraulic pressure, and the displacement of valve stem 2 exceeds X1. At this time, the fourth throttle port 13 gradually opens, and the return oil in cavity B enters cavity T1 through the fourth throttle port 13. The speed of the hoist motor 19 increases, and the motor returns oil at a large flow rate. The oil pressure in cavity B decreases, and the overflow valve closes.

[0021] After the crane hoist reaches the target position, the hoist control handle returns to the neutral position, and the hydraulic valve stem 2 returns to the neutral position. At this time, the oil in chamber B is discharged through the third throttle port with the main opening.

[0022] The curve showing the change in back pressure of the winch motor 19 with the displacement of the valve stem 2 during the process of the crane winch moving from a micro-motion to rapid lifting using this hydraulic valve can be used. Figure 3This indicates that when the valve stem 2 displacement is less than X1, the hoisting is in the micro-motion range, and the return oil from the hoisting motor 19 passes through the relief valve. The relief valve provides back pressure for the low-speed rotation of the hoisting motor 19, avoiding hoisting vibration caused by uneven speed during low-speed operation. When the valve stem 2 displacement is greater than X1, the fourth throttle port 13 opens, the speed of the hoisting motor 19 increases and stabilizes, and the motor returns oil through the throttle port. The oil pressure loss through the throttle port is low, and the return oil back pressure of the hoisting motor 19 is small. When the fourth throttle port 13 is opened to its maximum, as the return oil flow rate of the hoisting motor 19 continues to increase, the return oil back pressure gradually rises. In addition, this embodiment can also use a cartridge-type check valve to replace the relief valve to provide back pressure for the return oil of the hoisting motor.

Claims

1. A hydraulic control valve for a crane hoist, comprising a valve body (1), characterized in that, The valve body (1) is provided with a valve stem (2) for controlling the opening and closing of the oil port. The left and right end faces of the valve stem (2) are subjected to hydraulic pressure corresponding to the angle of the winch handle, which is used to adjust the working condition. The hydraulic valve stem (2) is provided with a U-shaped throttling groove along the cylindrical surface at the fourth throttling port (13). The valve body (1) is provided with an annular groove (10) at the fourth throttling port (13). An overflow valve (11) is installed on the valve body. The annular groove (10) and the oil inlet of the overflow valve (11) are connected through the oil passage on the valve body (1). The cavity T1 (12) is connected to the oil outlet of the overflow valve (11). The valve stem (2) is provided with an arc-shaped throttling groove at the third throttling port (9). When the valve stem (2) is in the middle position, the third throttling port (9) is open. The valve body (1) is provided with a second throttle port (6), which connects the cavity P (5) and the cavity P' (7). The output end of the cavity P' (7) is connected to the pressure compensator (16). The pressure compensator (16) is connected to the cavity A' (4) through the fifth throttle port (15), and the output end of the cavity A' (4) is connected to the cavity A (17) through the first throttle port (3). The output end of the cavity A (17) inputs the pressure oil into the balance valve (18), and the balance valve (18) drives the hoist motor (19) to rotate. The return oil from the hoist motor (19) enters the hydraulic valve cavity B (14) through the hydraulic pipeline. The oil in the cavity B (14) enters the annular groove (10) on the valve body (1) through the U-shaped throttling groove. The annular groove (10) is connected to the oil inlet of the overflow valve (11).

2. The crane hoist control hydraulic valve according to claim 1, characterized in that, The hydraulic pressure of the return oil in the cavity B (14) increases, and the overflow valve (11) is opened. The return oil returns through the outlet oil passage of the overflow valve (11). At this time, the hydraulic pressure of the return oil in the cavity B (14) causes the valve stem (2) to move by X1.

3. The crane hoist control hydraulic valve according to claim 1, characterized in that, The U-shaped throttling groove is provided in at least four sets.

4. A crane hoist control hydraulic valve according to claim 2, characterized in that, When the displacement of the valve stem (2) is less than X1, the hoisting is in the micro-motion range. At this time, the return oil of the hoisting motor passes through the overflow valve (11), and the overflow valve (11) provides back pressure for the hoisting motor (19) to rotate at low speed.

5. A crane hoist control hydraulic valve according to claim 1, characterized in that, When the displacement of the valve stem (2) is greater than X1, the fourth throttle port (13) opens, the speed of the winch motor (19) increases and stabilizes, and the winch motor (19) returns oil through the throttle port. When the oil pressure loss through the throttle port is low, the back pressure of the winch motor (19) returning oil is small. When the fourth throttle port (13) is opened to the maximum, the return oil flow rate of the winch motor (19) continues to increase.

6. A crane hoist control hydraulic valve according to claim 1, characterized in that, The overflow valve (11) is a cartridge-type check valve.

Images