Winch variable speed control system

Abstract

The invention belongs to the field of hydraulic transmission and control, and relates to a winch variable speed control system which comprises a winch motor, a winch motor speed reducer brake connected with the winch motor, a winch motor balance valve, a right two-position three-way reversing valve, a two-position two-way reversing valve, a first main reversing valve, a second main reversing valve and a left two-position three-way reversing valve. Oil inlets of the first main reversing valve and the second main reversing valve are respectively connected with a first pressure oil source P1 and a second pressure oil source P2; working oil ports of the first main reversing valve and the second main reversing valve are connected in series and then are respectively connected with a port A and a port B of a winch motor speed reducer; an oil control cavity of the winch motor speed reducer brake is respectively connected with working oil ways of the first main reversing valve and the second main reversing valve through a shuttle valve, a right two-position three-way reversing valve and a left two-position three-way reversing valve; and an oil outlet of the left two-position three-way reversing valve is connected with an oil control cavity of a winch motor speed reducer brake. Safe locking is ensured, control logic is clear, reliability is high, and expansibility is high.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission and control technology, and more specifically, to a hoist speed change control system. Background Technology

[0002] In construction machinery, the winch mechanism is a key component for lifting and lowering heavy objects. The performance of its hydraulic control system directly affects the overall efficiency and safety of the machine. Traditional winch hydraulic systems typically use a single multi-way valve to control one winch motor. To ensure safety, when the multi-way valve is in the neutral position, the pressure oil in the winch motor's reducer brake must be able to be unloaded, allowing the brake to lock under spring action and preventing the heavy object from falling. Therefore, the neutral position function of the multi-way valve is often selected as a "Y" type to allow for pressure relief between the various ports.

[0003] However, when it is necessary to use two or more independent oil sources to control the same hoist motor to achieve speed change function, the traditional solution faces an irreconcilable contradiction: If all multi-way valves use the "Y" type neutral position function: when one valve is working and the other valve is in the neutral position, the pressure oil will be directly unloaded through the "Y" type passage of the neutral position valve, and the brake will lock the reducer. Even if there is pressure oil in the hydraulic system, the motor cannot run.

[0004] If all multi-way valves use the "O" type neutral position function: in the non-working state, the pressure oil in the brake chamber is sealed and cannot be unloaded, the brake is in a semi-open state, causing the winch to slowly slide down under the load ("hook slippage"), which poses a major safety hazard.

[0005] Therefore, there is an urgent need in this field for a new type of hydraulic control system that can achieve stepless or stepped speed change from multiple oil sources and ensure that the brake is absolutely locked when not in operation. Summary of the Invention

[0006] To address the aforementioned deficiencies in the prior art, this invention provides a hoist speed control system, comprising: a hoisting motor, a hoisting motor reducer brake connected to the hoisting motor, a hoisting motor balance valve, a right two-position three-way directional valve, a two-position two-way directional valve, a first main directional valve, a second main directional valve, and a left two-position three-way directional valve; the oil inlets of the first and second main directional valves are respectively connected to a first pressure oil source P1 and a second pressure oil source P2, and the working oil ports of the first and second main directional valves are connected in series to ports A and B of the hoisting motor reducer; the control chamber of the hoisting motor reducer brake is connected to the working oil ports of the first and second main directional valves via a shuttle valve, the right two-position three-way directional valve, and the left two-position three-way directional valve. The system is as follows: The oil outlet of the left two-position three-way directional valve is connected to the control chamber of the winch motor reducer brake, the inlet is connected to the A port of the reducer motor, and its return port is connected to the oil tank T; The oil outlet of the right two-position three-way directional valve is connected to the control chamber of the winch motor reducer brake, the inlet is connected to the B port of the reducer motor, and its return port is connected to the oil tank T; The oil outlet of the two-position two-way directional valve is connected to the right control chamber of the left two-position three-way directional valve and the left control chamber of the right two-position three-way directional valve, respectively, and the oil inlet of the two-position two-way directional valve is connected to the control oil circuit Ps, which is used to control the left two-position three-way directional valve and the right two-position three-way directional valve to cut off the unloading oil circuit and to connect the oil circuit between the first main directional valve and the second directional valve and the winch motor.

[0007] Preferably, the two-position two-way directional valve is a two-position two-way solenoid directional valve. When energized, control oil Ps acts through the valve on the pilot control ports of the left two-position three-way directional valve and the right two-position three-way directional valve.

[0008] Preferably, the left two-position three-way directional valve is a two-position three-way directional valve, which has an unloading position that connects the oil control chamber of the winch motor reducer brake to the oil tank T, and a non-unloading position that cuts off the unloading oil circuit.

[0009] Preferably, the right two-position three-way directional valve is a two-position three-way directional valve, which has an unloading position that connects the oil control chamber of the winch motor reducer brake to the oil tank T, and a non-unloading position that cuts off the unloading oil circuit.

[0010] Preferably, both the first and second main directional valves are three-position four-way directional valves, with three working positions: left, middle, and right, which can realize the forward and reverse oil supply of pressure oil to the winch motor.

[0011] Preferably, the neutral position function of the first main directional valve and the second main directional valve is type O.

[0012] Preferably, the system also includes a pressure sensor for detecting system pressure and a flow meter for detecting system flow, the signal output terminals of which are connected to a controller.

[0013] Preferably, the first main directional valve and / or the second main directional valve are electro-hydraulic proportional directional valves, and their control terminals are connected to the controller.

[0014] Preferably, it also includes an overflow valve connected in parallel to the oil lines of the first pressure oil source P1 and the second pressure oil source P2, and a buffer valve installed near the working oil port of the hoist motor.

[0015] Preferably, the system provides at least three different input flow rates to the hoisting motor by controlling the combination of the working states of the first main directional valve and the second main directional valve, thereby achieving at least three different hoisting speeds.

[0016] The hoist speed control system of the present invention has the following beneficial effects: (1) Realized true multi-path interference-free speed change: solved the problem of pressure oil unloading caused by multiple "Y" type center position functional valves, so that multiple oil sources can work independently or in combination without interfering with each other; (2) Ensures absolute safety locking: A controlled brake unloading path independent of the main control valve is established. As long as the pilot control unit loses power, the brake can be reliably depressurized and locked. (3) Clear control logic and high reliability: The system uses the power supply of the pilot control unit as the "enable" signal, which is simple in logic and the components are mature and reliable; (4) High scalability: It can be expanded to control three or more oil sources. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort. The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings: Figure 1 This is a schematic diagram of the hoist speed control system of the present invention; Figure 2 yes Figure 1 Enlarged schematic diagram of the Q1 region; Figure 3 yes Figure 1 A magnified schematic diagram of the Q2 region.

[0018] In the diagram, 1-reducing mechanism brake, 2-hoisting motor balance valve, 3-right two-position three-way directional valve, 4-two-position two-way directional valve, 5-first main directional valve, 6-second main directional valve, 7-left two-position three-way directional valve. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] Figure 1 This is a schematic diagram of the hoist speed control system of the present invention; Figure 2 yes Figure 1 Enlarged schematic diagram of the Q1 region; Figure 3 yes Figure 1 A magnified view of the Q2 region. Please refer to [link / reference]. Figures 1-3In the hoisting speed control system provided in the first embodiment of the present invention, at least the following components are included: a hoisting motor, a hoisting motor reducer brake 1 connected to the hoisting motor, a hoisting motor balance valve 2, a right two-position three-way directional valve 3, a two-position two-way directional valve 4, a first main directional valve 5, a second main directional valve 6, and a left two-position three-way directional valve 7; the oil inlets of the first main directional valve 5 and the second main directional valve 6 are respectively connected to a first pressure oil source P1 and a second pressure oil source P2, and the working oil ports of the first main directional valve 5 and the second main directional valve 6 are connected in series to ports A and B of the hoisting motor reducer; the oil control chamber of the hoisting motor reducer brake 1 is connected to the first main directional valve 5 and the second main directional valve 6 respectively through a shuttle valve and the right two-position three-way directional valve 3 and the left two-position three-way directional valve 7. The working oil circuit is connected as follows: the oil outlet of the left two-position three-way directional valve 7 is connected to the control oil chamber of the winch motor reducer brake 1, the inlet is connected to the A port of the reducer winch motor, and its return oil port is connected to the oil tank T; the oil outlet of the right two-position three-way directional valve 3 is connected to the control oil chamber of the winch motor reducer brake 1, the inlet is connected to the B port of the reducer winch motor, and its return oil port is connected to the oil tank T; the oil outlet of the two-position two-way directional valve 4 is connected to the right position control chamber of the left two-position three-way directional valve 7 and the left position control chamber of the right two-position three-way directional valve 3 respectively, and the oil inlet of the two-position two-way directional valve 4 is connected to the control oil circuit Ps, which is used to control the left two-position three-way directional valve 7 and the right two-position three-way directional valve 3 to cut off the unloading oil circuit and to connect the oil circuit between the first main directional valve 5 and the second directional valve 6 and the winch motor.

[0023] The two-position two-way directional valve 4 is a two-position two-way solenoid directional valve. When it is energized, the control oil Ps acts through the valve on the pilot control ports of the left two-position three-way directional valve 7 and the right two-position three-way directional valve 3.

[0024] The left two-position three-way directional valve 7 is a two-position three-way directional valve, which has an unloading position that connects the oil control chamber of the winch motor reducer brake 1 to the oil tank T, and a non-unloading position that cuts off the unloading oil circuit.

[0025] The right two-position three-way directional valve 3 is a two-position three-way directional valve, which has an unloading position that connects the oil control chamber of the winch motor reducer brake 1 to the oil tank T, and a non-unloading position that cuts off the unloading oil circuit.

[0026] The first main directional valve 5 and the second main directional valve 6 are both three-position four-way directional valves, with three working positions: left, middle and right, which can realize the forward and reverse oil supply of pressure oil to the winch motor.

[0027] The neutral position function of the first main directional valve 5 and the second main directional valve 6 is type O.

[0028] The winch motor is the core actuator of the winch speed control system of this invention, which converts hydraulic energy into mechanical energy to drive the winch drum to rotate.

[0029] The winch motor reducer brake 1 is a normally closed brake, relying on spring force for braking and hydraulic oil pressure for release. Its function is to directly lock or release the winch motor's reduction mechanism, and it is a key component for safety assurance.

[0030] The hoist motor balance valve 2 is integrated into the motor or its port and includes an overload valve, a replenishing valve, and a balance valve. Its function is to prevent motor overspeed and load runaway, and to ensure smooth motor start-up and shutdown.

[0031] The first main directional valve 5 and the second main directional valve 6 are the operating input terminals of the hoist speed control system of the present invention, and can be, for example, three-position four-way manual directional valves. They control the on / off state and direction of the first pressure oil source P1 and the second pressure oil source P2, respectively. By operating the handle, the operator can select whether to supply oil to the system and the direction of oil supply.

[0032] The two-position two-way directional valve 4 is the main enable switch of the hoist speed control system of this invention, for example, a two-position two-way solenoid directional valve. Its energized / de-energized state determines whether the system enters the pre-operation state. When energized, control oil Ps is allowed to pass through to control subsequent valves.

[0033] Left 2-position 3-way directional valve 7: For example, a 2-position 3-way directional valve, controlled by pilot oil. Its core function is to control the unloading passage of the brake chamber. When it is in the initial position (left position), it provides a direct unloading path to the oil tank for the brake chamber; when pushed to the right position by the pilot oil, it cuts off this unloading path.

[0034] Right 2-position 3-way directional valve 3: For example, a 2-position 3-way directional valve, controlled by pilot oil. Its core function is to control the unloading passage of the brake chamber. When it is in the initial position (left position), it provides a direct unloading path to the oil tank for the brake chamber; when pushed to the right position by the pilot oil, it cuts off this unloading path.

[0035] Shuttle valve: Logic selection element. Its function is to compare the pressures of P1 and P2, and automatically direct the higher pressure oil to brake 2, ensuring that the brake can be reliably opened as long as either pressure oil is working.

[0036] In some optional implementations of this embodiment, to make the system more intelligent, accurate, and safe, the hoist speed control system of the present invention further includes a pressure sensor for detecting system pressure and a flow meter for detecting system flow. The signal output terminals of the pressure sensor and the flow meter are connected to a controller. The pressure sensor is installed in the P1 and P2 pipelines and the brake oil control chamber; the flow meter is installed in the oil inlet lines of P1 and P2. Their signal output lines are connected to a programmable logic controller (PLC).

[0037] The functions of electronic pressure sensors and flow meters are: real-time monitoring and fault diagnosis; when abnormal pressure or flow is detected, the controller can immediately alarm and de-energize the two-position two-way directional valve 4 for emergency braking; and provide feedback for closed-loop control.

[0038] In some optional implementations of this embodiment, to make the system more intelligent, precise, and safe, the first main directional valve 5 and / or the second main directional valve 6 in the hoist speed control system of this invention can be electro-hydraulic proportional directional valves, whose control terminals are connected to the controller. The electromagnet of the proportional valve receives a proportional current signal from the controller. The function of the electro-hydraulic proportional directional valve is: to enable stepless speed regulation: by changing the input current, the valve opening is continuously adjusted to achieve stepless speed regulation of the hoist motor; and to enable smooth control: significantly improving the smoothness during start-up, stopping, and directional switching.

[0039] In some optional implementations of this embodiment, the hoist speed control system of the present invention further includes an overflow valve connected in parallel to the oil lines of the first pressure oil source P1 and the second pressure oil source P2, and a buffer valve installed near the working oil port of the hoist motor.

[0040] The functions of relief valves and buffer valves are: to provide overload protection, with relief valves setting the maximum working pressure of the system to prevent system overload; and to absorb shocks, with buffer valves effectively absorbing hydraulic shocks and protecting the system.

[0041] The system provides at least three different input flow rates to the hoisting motor by controlling the combination of the working states of the first main directional valve 5 and the second main directional valve 6, thereby achieving at least three different hoisting speeds.

[0042] The core working principle of this invention is centralized oil supply, independent control, and centralized unloading.

[0043] Firstly, in non-working state (safety locked): The condition is: the two-position two-way directional valve 4 is de-energized.

[0044] Valve position: Two-position two-way directional valve 4 cuts off control oil Ps. Left two-position three-way directional valve 7 and right two-position three-way directional valve 3 are reset by pilot pressure: left two-position three-way directional valve 7 is in the left position (unloaded position) or right two-position three-way directional valve 3 is in the right position (unloaded position).

[0045] Action: The residual pressure oil in brake chamber 2 is quickly unloaded and returned to the oil tank through the left position of the left two-position three-way directional valve 7 or the right position of the right two-position three-way directional valve 3. Under the action of the spring, the brake immediately engages the winch motor reducer.

[0046] At this point, no matter how the operator moves the first main directional valve 5 or the second main directional valve 6, the hoisting mechanism will absolutely not be able to operate, ensuring safety.

[0047] Secondly, working status (hoist lifting): Prerequisite: Two-position two-way directional valve 4 is energized.

[0048] Valve position: Control oil Ps passes through two-position two-way directional valve 4, pushing the left two-position three-way directional valve 7 to the right position (cutting off the brake unloading path), establishing a passage between the main oil circuit and motor port A.

[0049] At this point, the system enters standby mode, and the specific speed is determined by operating the first main directional valve 5 and the second main directional valve 6. Speed ​​V1 (P1 oil supply only): Operate the second main directional valve 6 to the left position, while the first main directional valve 5 remains in the neutral position. P1 oil source is supplied separately at a flow rate of Q. P1 .

[0050] Speed ​​V2 (P2 oil supply only): Operate the first main directional valve 5 to the left position, and keep the second main directional valve 6 in the neutral position. P2 oil source is supplied separately, with a flow rate of Q. P2 .

[0051] Speed ​​V3 (P1 and P2 merge): Simultaneously operate the first main directional valve 5 and the second main directional valve 6 to the left position. The two oil sources merge for oil supply, with a total flow rate of Q. P1 + Q P2 This is the system's maximum speed.

[0052] Third, working status (hoist descending): The two-position two-way directional valve 4 also needs to be energized to release the brake.

[0053] Valve position: Control oil Ps passes through two-position two-way directional valve 4, pushing the right two-position three-way directional valve 3 to the left position (cutting off the brake unloading path), establishing a passage between the main oil circuit and motor port B.

[0054] Operate the first main directional valve 5 and / or the second main directional valve 6 to the right position. Pressurized oil enters the motor's B port, driving the motor to reverse. Oil returning from port A returns to the oil tank via the main directional valve in the right position. The right two-position three-way directional valve 3 and the winch motor balance valve 2 prevent stalling during this process.

[0055] In hydraulic system design and analysis, the formula for the relationship between the speed and flow rate of a hydraulic motor is: ,in, Output shaft speed (rpm) of the hydraulic motor. Input the actual flow rate (L / min) of the hydraulic motor. Volumetric efficiency (%) of hydraulic motors. Displacement of the hydraulic motor (mL / r).

[0056] This formula is the core of hydraulic transmission. It quantitatively describes the direct relationship between system flow rate and actuator speed.

[0057] This invention clearly explains the fundamental reasons for the generation of various speeds. By selecting oil sources with different flow rates or adjusting their output, the desired hoisting speed can be precisely set.

[0058] The formula for calculating hydraulic power is: ,in, Hydraulic power (kW) System operating pressure (MPa). Flow rate (L / min). This formula is used to calculate the power transmitted by a hydraulic system.

[0059] In this system design, this formula can be used for component selection (calculating the required power based on the maximum lifting force and speed) and energy consumption analysis.

[0060] Bernoulli's equation in fluid dynamics (simplified for pressure loss analysis) is as follows: ,in, Fluid pressure (Pa). Oil density (kg / m³) Fluid velocity (m / s) : Gravitational acceleration (m / s²) Height (m) Pressure loss (Pa).

[0061] Bernoulli's equation describes the conservation of energy in steady flow of an ideal fluid. In the pipeline design of this invention, this equation is used to predict the pressure loss of the system. .

[0062] The beneficial effects of the present invention, through the design of the above embodiments, are as follows: (1) Realized true multi-path interference-free speed change: solved the problem of pressure oil unloading caused by multiple "Y" type center position functional valves, so that multiple oil sources can work independently or in combination without interfering with each other; (2) Ensures absolute safety locking: A controlled brake unloading path independent of the main control valve is established. As long as the pilot control unit loses power, the brake can be reliably depressurized and locked. (3) Clear control logic and high reliability: The system uses the power supply of the pilot control unit as the "enable" signal, which is simple in logic and the components are mature and reliable; (4) High scalability: It can be expanded to control three or more oil sources.

[0063] This invention has been described with reference to specific embodiments, but those skilled in the art will understand that various changes and equivalent substitutions can be made without departing from the scope of the invention. Furthermore, numerous modifications can be made to this invention to suit specific applications without departing from its protection scope. Therefore, this invention is not limited to the specific embodiments disclosed herein, but includes all embodiments falling within the scope of the claims.

Claims

1. A hoist speed control system, characterized in that, include: The winch motor, the winch motor reducer brake (1) connected to the winch motor, the winch motor balance valve (2), the right two-position three-way directional valve (3), the two-position two-way directional valve (4), the first main directional valve (5), the second main directional valve (6), and the left two-position three-way directional valve (7); the oil inlets of the first main directional valve (5) and the second main directional valve (6) are respectively connected to the first pressure oil source P1 and the second pressure oil source P2, and the working oil ports of the first main directional valve (5) and the second main directional valve (6) are connected in series to the A and B ports of the winch motor reducer; the oil control chamber of the winch motor reducer brake (1) is connected to the working oil circuit of the first main directional valve (5) and the second main directional valve (6) through a shuttle valve and the right two-position three-way directional valve (3) and the left two-position three-way directional valve (7); the left two-position three-way directional valve (7) The outlet of the reversing valve (7) is connected to the control chamber of the winch motor reducer brake (1), the inlet is connected to the A port of the reducer winch motor, and its return port is connected to the oil tank T; the outlet of the right two-position three-way reversing valve (3) is connected to the control chamber of the winch motor reducer brake (1), the inlet is connected to the B port of the reducer winch motor, and its return port is connected to the oil tank T; the outlet of the two-position two-way reversing valve (4) is connected to the right control chamber of the left two-position three-way reversing valve (7) and the left control chamber of the right two-position three-way reversing valve (3), respectively, and the inlet of the two-position two-way reversing valve (4) is connected to the control oil circuit Ps, which is used to control the left two-position three-way reversing valve (7) and the right two-position three-way reversing valve (3) to cut off the unloading oil circuit and to connect the oil circuit between the first main reversing valve (5) and the second reversing valve (6) and the winch motor.

2. The hoist speed control system according to claim 1, characterized in that, The two-position two-way directional valve (4) is a two-position two-way solenoid directional valve. When it is energized, the control oil Ps acts through the valve on the pilot control ports of the left two-position three-way directional valve (7) and the right two-position three-way directional valve (3).

3. The hoist speed control system according to claim 1, characterized in that, The left two-position three-way directional valve (7) is a two-position three-way directional valve, which has an unloading station that connects the oil control chamber of the winch motor reducer brake (1) to the oil tank T, and a non-unloading station that cuts off the unloading oil circuit.

4. The hoist speed control system according to claim 1, characterized in that, The right two-position three-way directional valve (3) is a two-position three-way directional valve, which has an unloading position that connects the oil control chamber of the winch motor reducer brake (1) to the oil tank T, and a non-unloading position that cuts off the unloading oil circuit.

5. The hoist speed control system according to claim 1, characterized in that, The first main directional valve (5) and the second main directional valve (6) are both three-position four-way directional valves with three working positions: left, middle and right, which can realize the forward and reverse oil supply of pressure oil to the winch motor.

6. The hoist speed control system according to claim 5, characterized in that, The neutral position function of the first main directional valve (5) and the second main directional valve (6) is type O.

7. The hoist speed control system according to claim 1, characterized in that, It also includes a pressure sensor for detecting system pressure and a flow meter for detecting system flow, the signal output terminals of which are connected to a controller.

8. The hoist speed control system according to claim 7, characterized in that, The first main directional valve (5) and / or the second main directional valve (6) are electro-hydraulic proportional directional valves, and their control terminals are connected to the controller.

9. The hoist speed control system according to claim 1, characterized in that, It also includes an overflow valve connected in parallel to the oil lines of the first pressure oil source P1 and the second pressure oil source P2, and a buffer valve installed near the working oil port of the hoist motor.

10. The hoist speed control system according to any one of claims 1-9, characterized in that, The system provides at least three different input flow rates to the hoisting motor by controlling the working state combination of the first main directional valve (5) and the second main directional valve (6), thereby achieving at least three different hoisting speeds.

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