Winch balance valve, winch hydraulic system and hoisting engineering machinery

Abstract

The present application relates to hydraulic balance valve, disclose a kind of hoist balance valve, hoist hydraulic system and hoisting engineering machinery, the hoist balance valve includes balance valve core, for controlling hoist brake hoist brake valve, first oil port and second oil port, the balance valve core is arranged on the oil circuit between the first oil port of the hoist balance valve and its second oil port, the hoist brake valve includes the oil inlet for being connected with system low pressure control oil circuit, the oil inlet of the hoist brake valve is provided with pressure maintaining oil circuit between the second oil port of the hoist balance valve, the pressure maintaining oil circuit is equipped with check valve, to enable hydraulic oil by the oil inlet of the hoist brake valve one-way output to the second oil port of the hoist balance valve.The present application can reduce the abnormal sound caused by the collision between gear teeth and the pressure fluctuation caused thereby during the process that hoist motor is from static to work.

Description

Technical Field

[0001] This invention relates to hydraulic balancing valves, and more specifically, to a winch balancing valve. It also relates to a winch hydraulic system and lifting machinery. Background Technology

[0002] Truck cranes, crawler cranes, and other lifting machinery typically use a hydraulic motor and reducer to control the winch's movement. During operation, the hydraulic system drives the hydraulic motor, which in turn rotates the winch reducer, ultimately causing the wire rope to directly lift the load or move it through a pulley system, enabling the load to be raised and lowered. Because lifting conditions vary in speed and load requirements, the winch mechanism starts and brakes relatively frequently, and operating conditions are often harsh. For operational performance, the winch mechanism must start, brake, and operate stably and reliably without impact. For safety, the winch mechanism must be able to maintain the load for extended periods, preventing accidents such as the load falling when suspended in the air. Therefore, the requirements for leakage in the winch system's balance valve and the flexibility of valve cores and other components are extremely high.

[0003] The hoisting system is also equipped with a hoist brake and a balance valve to maintain the safety of the hoisting system. Specifically, refer to... Figure 1 The first working port A1 of the main valve is connected to the first port A2 of the hoisting motor 9 through the balance valve 10. The first working port A1 of the main valve is connected to the pressure reducing valve 11 through the shuttle valve. The pressure reducing valve 11 is connected to the control port K1 of the hoisting brake. The second working port B1 of the main valve is connected to the second port B2 of the hoisting motor 9. At the same time, the second working port B1 of the main valve is connected to the pressure reducing valve 11 through the shuttle valve. When lifting a heavy object, a portion of the hydraulic oil output from the first working port A1 of the main valve reaches the first port A2 of the winch motor 9 via the balance valve 10, driving the winch motor. At the same time, another portion of the hydraulic oil output from the first working port A1 of the main valve is output to the control port K1 of the winch brake via the shuttle valve and the pressure reducing valve 11, opening the winch brake and realizing the winch lifting action. When lowering a heavy object, a portion of the hydraulic oil output from the second working port B1 of the main valve is output to the second port B2 of the winch motor 9, driving the winch motor. At the same time, another portion of the hydraulic oil output from the second working port B1 of the main valve is output to the control port K1 of the winch brake via the shuttle valve and the pressure reducing valve 11, opening the winch brake and realizing the winch lowering action.

[0004] However, due to uncontrollable internal leakage in the winch motor 9, some oil leaks from the high-pressure chamber of the winch motor 9 to the zero-pressure leakage oil circuit of the system. The oil pressure between the second port B of the winch balance valve and the first port A2 of the winch motor 9 decreases due to this internal leakage. Simultaneously, the unavoidable clearance between the motor spline and the winch reducer gears causes the transmission and driven parts to float. When the oil pressure between the second port B of the winch balance valve and the first port A2 of the winch motor 9 decreases, gaps appear between the originally tightly fitted gear teeth. When the winch system is restarted after a period of inactivity, the gaps between the gear teeth quickly disappear under the pressure of the oil, causing the teeth to collide rapidly, producing abnormal noise and pressure fluctuations. Summary of the Invention

[0005] The technical problem to be solved by the first aspect of the present invention is to provide a hoisting balance valve that can reduce the abnormal noise caused by the collision between the gear teeth and the resulting pressure fluctuation during the process of the hoisting motor from standstill to operation.

[0006] To address the aforementioned technical problems, the first aspect of this invention provides a winch balance valve, comprising a balance valve core, a winch brake valve for controlling a winch brake, a first oil port, and a second oil port. The balance valve core is arranged in an oil passage between the first oil port and the second oil port of the winch balance valve. The winch brake valve includes an oil inlet for connecting to a low-pressure control oil passage of the system. A pressure-holding oil passage is provided between the oil inlet of the winch brake valve and the second oil port of the winch balance valve. A one-way valve is provided in the pressure-holding oil passage to allow hydraulic oil to be output unidirectionally from the oil inlet of the winch brake valve to the second oil port of the winch balance valve.

[0007] Optionally, a damper is also provided in the pressure-holding oil circuit.

[0008] Furthermore, it also includes a third oil port and a shuttle valve, the shuttle valve including a first oil inlet connected to the first oil port of the hoisting balance valve, a second oil inlet connected to the third oil port of the hoisting balance valve, and an oil outlet connected to the control port of the hoisting brake valve.

[0009] Optionally, the third oil port of the hoisting balance valve is connected to the pilot control port of the balance valve core.

[0010] Optionally, a filter is provided in the pilot oil line between the third oil port of the hoisting balance valve and the pilot control port of the balance valve core.

[0011] Optionally, the winch brake valve includes an oil outlet for connection to the control port of the winch brake.

[0012] The technical problem to be solved by the second aspect of the present invention is to provide a winch hydraulic system that can reduce the abnormal noise caused by the collision between the gear teeth and the resulting pressure fluctuation during the process of the winch motor from standstill to operation.

[0013] To solve the above-mentioned technical problems, a second aspect of the present invention provides a winch hydraulic system, including a winch motor, a main valve, and a winch balance valve as described in any of the above technical solutions. The first working port of the main valve is connected to the first port of the winch balance valve, the second working port of the main valve is connected to the third port of the winch balance valve and the second port of the winch motor, respectively, and the first port of the winch motor is connected to the second port of the winch balance valve.

[0014] Optionally, the winch motor is provided with an oil drain port.

[0015] Optionally, the oil drain port of the hoist motor is connected to the leakage oil circuit.

[0016] The technical problem to be solved by the third aspect of the present invention is to provide a lifting engineering machine with good stability of the hoisting system.

[0017] To solve the above-mentioned technical problems, a third aspect of the present invention provides a lifting engineering machinery, including the winch hydraulic system described in any one of the above technical solutions.

[0018] The beneficial effects of the present invention through the above technical solution are as follows:

[0019] This invention provides a pressure-holding oil circuit between the inlet of the winch brake valve and the second port of the winch balance valve. This pressure-holding oil circuit is connected to the system's low-pressure control oil circuit. The oil output from the system's low-pressure control oil circuit can be output to the second port of the winch balance valve via the pressure-holding oil circuit. Furthermore, when the winch balance valve of this invention is applied to a specific winch hydraulic circuit, the second port of the winch balance valve is connected to one end of the winch motor's inlet, allowing the splines and gears in the winch motor and winch reducer to engage tightly. Therefore, during the process of the winch motor moving from a stationary state to the winch lifting state, the gaps between the gear teeth can be eliminated in advance, reducing or even avoiding collisions and abnormal noises caused by the splines and gears moving from a floating state to a tightly engaged state, thus improving the stability of the winch hydraulic system and extending the lifespan of the winch reducer.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a hydraulic schematic diagram of an existing hoist hydraulic system;

[0023] Figure 2 This is a hydraulic schematic diagram of the hoisting hydraulic system according to a specific embodiment of the present invention;

[0024] Figure 3 This is one of the structural schematic diagrams of the interaction between the hoisting motor and the hoisting reducer in a specific embodiment of the present invention;

[0025] Figure 4 This is the second schematic diagram of the interaction between the hoisting motor and the hoisting reducer in a specific embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures

[0027] 1. Balance valve core 2. Winch brake

[0028] K1 hoist brake control port 3 hoist brake valve

[0029] P is the inlet of the winch brake valve, and T is the return port of the winch brake valve.

[0030] K hoist brake valve outlet Z hoist brake valve control port

[0031] 4. System low-pressure control oil circuit; 5. Check valve

[0032] 6-damped 7-shuttle valve

[0033] a) First oil inlet of shuttle valve b) Second oil inlet of shuttle valve

[0034] C shuttle valve outlet filter 8

[0035] A. First oil port of the hoisting balance valve; B. Second oil port of the hoisting balance valve

[0036] The third oil port of the X-type winch balance valve is 9, which is the winch motor.

[0037] The first oil port of the A2 hoist motor; the second oil port of the B2 hoist motor.

[0038] T1 hoist motor oil drain port 100 leak oil circuit

[0039] A1 is the first working port of the main valve; B1 is the second working port of the main valve.

[0040] 10 Balancing valve 11 Pressure reducing valve

[0041] 10a hoist motor key shaft 11a hoist reducer

[0042] 12a load-bearing weight Detailed Implementation

[0043] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," or "connection" should be interpreted broadly. For example, the term "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or more of the stated features.

[0046] First, it should be noted that the winch balance valve of this invention belongs to the field of hydraulics. For those skilled in the art, its essential technical concept lies in the hydraulic connection relationship. Related hydraulic components, such as pressure reducing valves, directional valves, hydraulic motors, and check valves, are well-known to those skilled in the art and are commonly used components in existing hydraulic systems. Therefore, these hydraulic components will only be briefly described below. After understanding the technical concept of this invention, those skilled in the art can also make simple substitutions to the oil circuits or valves to achieve the function of the winch balance valve of this invention, which also falls within the scope of protection of this invention.

[0047] In this invention, the directional terms used are based on the orientation or positional relationship shown in the accompanying drawings, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. The directional terms of this invention should be understood in conjunction with the actual installation state.

[0048] like Figure 2As shown, the winch balance valve of the basic embodiment of the present invention includes a balance valve core 1, a winch brake valve 3 for controlling the winch brake 2, a first oil port A, and a second oil port B. The balance valve core 1 is arranged in the oil line between the first oil port A and the second oil port B of the winch balance valve. The winch brake valve 3 includes an oil inlet P for connecting to the low-pressure control oil line 4 of the system. A pressure-holding oil line is provided between the oil inlet P of the winch brake valve 3 and the second oil port B of the winch balance valve. A one-way valve 5 is provided in the pressure-holding oil line so that hydraulic oil can be output unidirectionally from the oil inlet P of the winch brake valve 3 to the second oil port B of the winch balance valve.

[0049] To facilitate understanding of the technical solution of the winch balance valve of the present invention, the winch balance valve of the present invention is combined with a specific winch hydraulic system, and the first oil port A2 of the winch motor 9 is used as the lifting oil port and the second oil port B2 of the winch motor 9 is the lower oil port as an example for explanation.

[0050] Although the following embodiments are described with the first oil port A2 of the winch motor 9 used for lifting and the second oil port B2 of the winch motor 9 used for lowering as examples, it is understood that the first oil port A2 of the winch motor 9 can also be used for lowering and the second oil port B2 of the winch motor 9 can be used for lifting.

[0051] To address the problem in existing technologies where uncontrollable internal leakage in the winch motor 9 causes rapid collisions between gear teeth upon restarting of the winch hydraulic system after a shutdown, resulting in abnormal noise and pressure fluctuations, this invention specifically designs the winch balance valve. Specifically, a pressure-holding oil circuit is established between the inlet P of the winch brake valve 3 and the second oil port B of the winch balance valve. A one-way valve 5 is installed on this pressure-holding oil circuit, ensuring that the oil flows unidirectionally from the inlet P of the winch brake valve 3 to the second oil port B of the winch balance valve. After installing the winch balance valve in the winch hydraulic system, refer to... Figure 2 The inlet P of the winch brake valve 3 is connected to the low-pressure control oil circuit 4 of the system, and the second oil port B of the winch balance valve is connected to the first oil port A2 of the winch motor 9. Thus, although the winch motor 9 has uncontrollable internal leakage, with some oil leaking from the high-pressure chamber of the winch motor 9 through the drain port T1 to the zero-pressure leakage oil circuit 100 of the system, the present invention can continuously replenish oil to the winch motor 9 through the low-pressure control oil circuit 4 of the system, ensuring that the winch motor 9 always has a portion of back pressure. This eliminates the gap between the spline and the gear, preventing collisions that occur when the spline and gear change from a floating state to a tightly fitted state, or changing the gap position of the spline and gear connection, thus buffering the impact of collisions that occur when the spline and gear change from a floating state to a tightly fitted state. This effectively reduces the collisions and pressure fluctuations caused by the internal leakage of the motor when the connecting parts change from a floating state to a tightly fitted state, greatly improving the stability of the winch hydraulic system and extending the life of the winch reducer.

[0052] Furthermore, as a specific embodiment, the winch brake valve 3 can be controlled by hydraulic pilot operation. Preferably, the winch brake valve 3 can be a two-position three-way directional valve; see reference. Figure 2 A third oil port X is provided on the winch balance valve, and a shuttle valve 7 is provided inside the winch balance valve. The first oil inlet a of the shuttle valve 7 is connected to the first oil port A of the winch balance valve, the second oil inlet b of the shuttle valve 7 is connected to the third oil port X of the winch balance valve, and the oil outlet c of the shuttle valve 7 is connected to the control port Z of the winch brake valve 3. The second oil port B2 of the winch motor 9 is connected to the second working oil port B1 of the main valve, and the third oil port X of the winch balance valve is also connected to the second working oil port B1 of the main valve. The first oil port A2 of the winch motor 9 is connected to the winch brake valve 3. The second oil port B of the winch balance valve is connected, and the first oil port A of the winch balance valve is also connected to the first working oil port A1 of the main valve. The oil outlet K of the winch brake valve 3 is connected to the control port K1 of the winch brake 2. Because of the shuttle valve 7, the oil pressure between the first oil inlet a and the second oil inlet b of the shuttle valve 7 is compared. Oil is output to the control port Z of the winch brake valve 3 through the oil outlet c of the shuttle valve 7, driving the valve core of the winch brake valve 3 to switch direction, causing the winch brake 2 to open, and causing the winch motor 9 to rotate, thus lifting or lowering the load. Alternatively, the winch brake valve 3 can be controlled electrically; for example, the winch brake valve 3 can be a two-position three-way solenoid directional valve.

[0053] During operation, when the main winch control handle is moved in the upward direction, the hydraulic oil output from the first working port A1 of the main valve flows mostly through the balance valve core 1 to the first port A2 of the winch motor 9. Simultaneously, a small portion of the hydraulic oil flows to the first inlet a of the shuttle valve 7. The pressure between the first inlet a and the second inlet b of the shuttle valve 7 is compared. The oil with the higher pressure is output through the outlet c of the shuttle valve 7 to the control port Z of the winch brake valve 3, driving the valve core of the winch brake valve 3 to reverse. This causes the low-pressure control oil circuit 4 to supply low-pressure control oil to the winch brake 2, opening the winch brake 2 and allowing the winch motor 9 to rotate, thus lifting the load. When the main winch control handle is moved in the downward direction, the second working port B1 of the main valve outputs hydraulic oil, with the majority of the hydraulic oil flowing to the second port A2 of the winch motor 9. Hydraulic oil is output from port B2. A small portion of the hydraulic oil flows to the third port X. This portion of hydraulic oil is divided into two parts. One part flows to the pilot control port of the balance valve core 1, driving the valve core 1 to switch direction, so that the hydraulic oil output from the first port A2 of the hoisting motor 9 can flow back to the oil tank through the balance valve core 1. Moreover, a throttling orifice is provided inside the channel of the balance valve core 1, which can allow the hydraulic oil to flow back slowly, ensuring the stability of the lowering action. The other part flows to the second inlet b of the shuttle valve 7. The pressure between the first inlet a and the second inlet b of the shuttle valve 7 is compared. The oil with the higher pressure is output to the control port Z of the hoisting brake valve 3 through the outlet c of the shuttle valve 7, driving the valve core of the hoisting brake valve 3 to switch direction, so that the low-pressure control oil circuit 4 of the system provides low-pressure control oil to the hoisting brake 2, so that the hoisting brake 2 opens, allowing the hoisting motor 9 to rotate and drive the heavy object to be lowered. In the above-mentioned method of supplying low-pressure control oil to the winch brake 2 through the winch brake valve 3 via the low-pressure control oil circuit 4, both the winch brake 2 and the winch brake valve 3 can use springs with low stiffness, so that both the winch brake valve 3 and the winch brake 2 have low opening pressure. Here, low pressure means that the oil pressure is 1-2 MPa. Opening the winch brake 2 and providing a certain pre-pressure to the winch motor 9 only requires 1-2 MPa. The pressure difference between the first oil inlet a and the second oil inlet b of the shuttle valve 7 is actually related to the pressure difference between the first working oil port A1 and the second working oil port B1 of the main valve. That is to say, when the main winch operating handle is operated in the hoisting upward direction or in the hoisting downward direction, there is a pressure difference between the first working oil port A1 and the second working oil port B1 of the main valve, so that control oil can be output to the control port Z of the winch brake valve 3 through the oil outlet c of the shuttle valve 7.When the load pressure is low, i.e., when the pressure at the first working port A1 and the second working port B1 of the main valve is very low, it can still act on the control port Z of the winch brake valve 3. This allows low-pressure control oil to be output through the outlet K of the winch brake valve 3 to the control port K1 of the winch brake 2, causing the winch brake 2 to open and the winch motor 9 to rotate. This enables the entire winch hydraulic system to operate normally even at very low system pressures, reducing energy waste caused by the need for higher system back pressure to ensure the winch brake 2 opens normally. Simultaneously, a separate low-pressure control oil circuit 4 provides low-pressure control oil to the winch brake 2, preventing the main winch oil circuit from directly controlling the opening and closing of the winch brake 2. This avoids the winch brake 2 from oscillating during opening and closing due to load fluctuations, improving the stability of the winch system. The main valve is a conventional hydraulic component in the hydraulic control system. Under the technical concept of this invention, those skilled in the art can specifically apply the main valve to the winch hydraulic system of this invention, which will not be elaborated further here. Furthermore, the winch motor 9 can be a bidirectional hydraulic motor.

[0054] In addition, the winch motor 9 is provided with an oil drain port T1, which can be connected to the leakage oil circuit 100, or directly connected to the oil tank. Furthermore, the return port T of the winch brake valve 3 can also be connected to the leakage oil circuit 100, or directly connected to the oil tank.

[0055] This invention establishes a pressure-holding oil circuit between the oil inlet P of the winch brake valve 3 and the second oil port B of the winch balance valve, providing pre-pressure to the winch motor 9. This effectively reduces collisions and pressure fluctuations caused by internal leakage in the winch motor 9, which leads to the transition of connecting parts from a floating state to a tightly fitted state. Furthermore, a damper 6 can be installed on the pressure-holding oil circuit to limit the flow of oil within it. The number of dampers 6 can be one or more. Installing a one-way valve 5 and a damper 6 connected in series with it on the pressure-holding oil circuit ensures that while providing pre-pressure to the winch motor 9, it does not affect the low-pressure control oil circuit 4's supply of low-pressure control oil for the opening and closing of the winch brake 2; it also prevents the high-pressure main oil circuit from affecting the control oil circuit when the main oil circuit pressure increases.

[0056] Generally, in order to filter impurities in the hydraulic oil, a filter 8 can be installed in the pilot oil line between the third oil port X and the pilot control port of the balance valve core 1; a first one-way throttle valve is installed between the pilot control port of the balance valve core 1 and the filter 8; a second one-way throttle valve is installed between the spring control chamber of the balance valve core 1 and the second oil port B of the winch balance valve, and the one-way throttle valve is composed of a one-way valve and a throttle valve connected in parallel; so that the switching of the balance valve core 1 can be carried out slowly, thereby enhancing the operating stability of the winch motor 9.

[0057] To better understand the technical solution of the present invention, the hoisting hydraulic system is described below in conjunction with a more comprehensive description of its technical features.

[0058] like Figure 2 As shown, in the preferred embodiment of the winch hydraulic system of the present invention, the first working port A1 of the main valve is connected to the first port A of the winch balance valve, the second port B2 of the winch motor 9 is connected to the second working port B1 of the main valve, and the third port X of the winch balance valve is also connected to the second working port B1 of the main valve; the first port A2 of the winch motor 9 is connected to the second port B of the winch balance valve; inside the winch balance valve, the balance valve core 1 is arranged in the oil circuit between the first port A and the second port B of the winch balance valve, and a pressure-holding oil circuit is provided between the inlet P of the winch brake valve 3 and the second port B of the winch balance valve. Meanwhile, the oil inlet P of the winch brake valve 3 is also connected to the system low-pressure control oil circuit 4, so that the system low-pressure control oil circuit 4 is connected to the first oil port A2 of the winch motor 9, and the oil outlet K of the winch brake valve 3 is connected to the control port K1 of the winch brake 2, for providing low-pressure control oil to the winch brake 2; the first oil inlet a of the shuttle valve 7 is connected to the first oil port A of the winch balance valve, the second oil inlet b of the shuttle valve 7 is connected to the third oil port X of the winch balance valve, and the oil outlet c of the shuttle valve 7 is connected to the control port Z of the winch brake valve 3; the oil return port T of the winch brake valve 3 and the oil drain port T1 of the winch motor 9 are both connected to the leakage oil circuit 100.

[0059] During the operation of the main winch control handle in the lifting or lowering direction, both the winch brake valve 3 and the winch brake 2 utilize springs with low stiffness, resulting in lower opening pressure. This allows the entire winch hydraulic system to operate normally even at low system pressures, reducing energy waste caused by the higher system back pressure required to ensure the winch brake 2 opens properly. Simultaneously, a separate low-pressure control oil circuit 4 provides low-pressure control oil to the winch brake 2, preventing the main winch oil circuit from directly controlling its opening and closing. This avoids oscillating opening and closing of the winch brake 2 due to load fluctuations, thus improving the stability of the winch system.

[0060] Meanwhile, due to the installation of a pressure-holding oil circuit, refer to Figure 3During the process of the winch hydraulic system moving from a standstill to hoisting, the gears of the winch motor key shaft 10a and the winch reducer 11a are in a tightly meshed state. Since the winch brake 2 is not activated, the winch motor 9 will not rotate under the action of the winch brake 2, keeping the system stationary. When moving from a standstill to the start of hoisting, due to the pre-pressure provided by the pressure-holding oil circuit, the spline and gear are always tightly engaged during the initial rotation of the winch motor 9, preventing collisions between the spline and gear. At the same time, due to the presence of the check valve 5 and the flow-limiting damper 6, the oil flowing from the pressure-holding oil circuit to the first oil port A2 of the winch motor 9 has a negligible impact compared to the main oil from the first working oil port A1 of the main valve, and will not affect the normal operation of the system's low-pressure control oil circuit 4 and the winch brake valve 3.

[0061] During the lowering process of the heavy load hoist, the load 12a has a large mass, meaning the hoist hydraulic system is under heavy load. The hoist motor key shaft 10a abuts against the upper side of the gear teeth of the hoist reducer 11a. At this time, the hoist motor 9 plays a supporting role during the lowering process, preventing the load from stalling during the fall. Due to the pre-pressure provided by the pressure-holding oil circuit, the spline and gear are always tightly engaged during the initial rotation of the hoist motor 9, thus preventing collision between the spline and gear. When the hoist motor 9 rotates normally, the oil output from the system's low-pressure control oil circuit 4 flows into the main oil circuit and enters the system return oil through the first working port A1 of the main valve in the main oil circuit.

[0062] During the lowering process of the lightly loaded winch, refer to Figure 4 At this time, the load 12a is relatively light, meaning the winch hydraulic system is lightly loaded. As the pressure gradually builds up at port B2 of the winch motor 9, the pre-pressure provided by the pressure-holding oil circuit at the first oil port A2 of the winch motor 9 gradually decreases as the balance valve core 1 opens. The pressure provided by the system's low-pressure control oil circuit 4 buffers the change in gear clearance position, causing the lower side of the gear teeth of the winch motor key shaft 10a to gradually contact the winch reducer 11a. Due to the light load, this reduces the abnormal noise caused by gear tooth collisions and the resulting pressure fluctuations. Because of the damping 6, the oil flow from the system's low-pressure control oil circuit 4 to the main oil circuit is very small, and the pressure in the system's low-pressure control oil circuit 4 will not decrease, thus not affecting the normal opening and closing of the winch brake.

[0063] As can be seen, this invention introduces a portion of the oil from the low-pressure control oil circuit 4 into the first oil port A2 of the winch motor 9, ensuring a tight fit between the splines and gears in the winch motor and winch reducer. This eliminates gaps beforehand during the winch hydraulic system's transition from a stationary state to lifting and during heavy load lowering, preventing collisions between the splines and gears as they transition from a floating to a tightly fitted state. During light load lowering, it also buffers changes in the gap between the splines and gears. Therefore, it effectively reduces collisions and pressure fluctuations caused by internal leakage in the winch motor 9, leading to a transition from a floating to a tightly fitted state. This significantly improves the stability of the winch hydraulic system and extends the lifespan of the winch reducer.

[0064] The winch hydraulic system provided by this invention can be applied to lifting machinery such as truck cranes and crawler cranes, giving the lifting machinery better working stability, and reducing internal abnormal noises and pressure fluctuations.

[0065] It should be noted that lifting machinery such as truck cranes and crawler cranes usually have main and auxiliary winch systems. The main and auxiliary winch systems have two sets of winch hydraulic systems with the same design. Both the main and auxiliary winch systems can use the winch balance valve and winch hydraulic system of this invention.

[0066] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0067] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0068] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A hoisting balancing valve, characterized in that, The system includes a balance valve core (1), a winch brake valve (3) for controlling a winch brake (2), a first oil port (A), and a second oil port (B). The balance valve core (1) is arranged in the oil line between the first oil port (A) and the second oil port (B) of the winch balance valve. The winch brake valve (3) includes an oil inlet (P) for connecting to the low-pressure control oil line (4) of the system. A pressure-holding oil line is provided between the oil inlet (P) of the winch brake valve (3) and the second oil port (B) of the winch balance valve. A check valve (5) is provided in the pressure-holding oil line so that hydraulic oil can be output unidirectionally from the oil inlet (P) of the winch brake valve (3) to the second oil port (B) of the winch balance valve.

2. The hoisting balance valve according to claim 1, characterized in that, The pressure-holding oil circuit is also equipped with a damper (6).

3. The hoisting balance valve according to claim 1 or 2, characterized in that, It also includes a third oil port (X) and a shuttle valve (7), the shuttle valve (7) including a first oil inlet (a) connected to the first oil port (A) of the hoisting balance valve, a second oil inlet (b) connected to the third oil port (X) of the hoisting balance valve, and an oil outlet (c) connected to the control port (Z) of the hoisting brake valve (3).

4. The hoisting balance valve according to claim 3, characterized in that, The third oil port (X) of the hoisting balance valve is connected to the pilot control port of the balance valve core (1).

5. The hoisting balance valve according to claim 4, characterized in that, A filter (8) is provided on the pilot oil line between the third oil port (X) of the hoisting balance valve and the pilot control port of the balance valve core (1).

6. The hoisting balance valve according to claim 1 or 2, characterized in that, The winch brake valve (3) includes an oil outlet (K) for connection to the control port (K1) of the winch brake (2).

7. A hoisting hydraulic system, characterized in that, The system includes a winch motor (9), a main valve, and a winch balance valve according to any one of claims 1 to 6. The first working port (A1) of the main valve is connected to the first port (A) of the winch balance valve, the second working port (B1) of the main valve is connected to the third port (X) of the winch balance valve and the second port (B2) of the winch motor (9), and the first port (A2) of the winch motor (9) is connected to the second port (B) of the winch balance valve.

8. The hoisting hydraulic system according to claim 7, characterized in that, The winch motor (9) is provided with an oil drain port (T1).

9. The hoisting hydraulic system according to claim 8, characterized in that, The oil drain port (T1) of the hoist motor (9) is connected to the leakage oil passage (100).

10. A type of lifting machinery, characterized in that, Includes the winch hydraulic system according to any one of claims 7 to 9.

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