Hydraulic control systems, operating machinery and power output control methods

Abstract

This invention relates to the field of hydraulic system technology, providing a hydraulic control system, a working machine, and a power output control method. In the hydraulic control system, a pressure regulating valve group is connected to an oil source to regulate the output pressure of the oil source. An auxiliary power actuator is connected to the rear drive axle. An auxiliary power control valve group is connected between the oil source and the auxiliary power actuator. A transmission ratio detection device is used to detect the transmission ratio. The control device adjusts the working state of the auxiliary power control valve group and the set pressure of the pressure regulating valve group based on the detection results of the transmission ratio detection device. The control device can not only control the starting state of the auxiliary power actuator through the auxiliary power control valve group, but also flexibly adjust the set pressure of the pressure regulating valve group based on the transmission ratio, thereby controlling the output pressure of the oil source. This not only improves the actual working efficiency of the hydraulic control system but also reduces energy waste during operation.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system technology, and in particular to a hydraulic control system, a working machine, and a power output control method. Background Technology

[0002] Cranes and other construction machinery are indispensable equipment in modern society. During use, the target working position or work site of the machinery is usually adjusted. The driving force required by the machinery varies under different working conditions. Currently, a hydraulic auxiliary power system is typically installed on the rear drive axle. This system is activated when the front drive axle lacks power to supplement the driving force of the machinery. In existing technology, when the front drive axle lacks power, the hydraulic auxiliary power system usually operates at maximum power output, resulting in low actual working efficiency and energy waste. Summary of the Invention

[0003] This invention provides a hydraulic control system, a working machine, and a power output control method to solve the problem that existing auxiliary power systems usually operate at maximum output power, resulting in low actual working efficiency and energy waste.

[0004] According to a first aspect of the present invention, a hydraulic control system is provided, comprising:

[0005] Oil source;

[0006] A pressure regulating valve assembly is connected to the oil source and is used to regulate the output pressure of the oil source;

[0007] Auxiliary power actuator, used to connect to the rear drive axle of the operating machinery;

[0008] An auxiliary power control valve assembly is connected between the oil source and the auxiliary power actuator and is used to control the connection state between the oil source and the auxiliary power actuator.

[0009] Transmission ratio detection device, used to detect the transmission ratio of the transmission structure of working machinery;

[0010] A control device is connected to the transmission ratio detection device, the auxiliary power control valve group, and the pressure regulating valve group, and is used to adjust the working state of the auxiliary power control valve group and the set pressure of the pressure regulating valve group based on the detection result of the transmission ratio detection device.

[0011] According to a hydraulic control system provided by the present invention, the pressure regulating valve group includes an electro-proportional relief valve and a relief logic valve. The oil source includes a hydraulic pump and an oil tank.

[0012] The inlet of the hydraulic pump is connected to the oil tank. The outlet of the hydraulic pump is connected to the inlet of the electro-proportional relief valve. The outlet of the electro-proportional relief valve is connected to the oil tank. The inlet of the relief logic valve is connected to the outlet of the hydraulic pump. The outlet of the relief logic valve is connected to the oil tank. The spring control port of the relief logic valve is connected to the inlet of the electro-proportional relief valve.

[0013] According to a hydraulic control system provided by the present invention, the hydraulic control system further includes a speed detection device. The speed detection device is used to detect the speed of the front drive axle of the working machinery. The control device is connected to the speed detection device and the hydraulic pump. The control device is used to control the flow rate of the hydraulic pump based on the detection result of the speed detection device.

[0014] According to a hydraulic control system provided by the present invention, the auxiliary power control valve group includes a flow logic valve and a status control valve.

[0015] The inlet of the flow logic valve is connected to the outlet of the hydraulic pump. The outlet of the flow logic valve is connected to the auxiliary power execution unit. The state control valve is connected to the outlet of the hydraulic pump, the oil tank, and the spring control port of the flow logic valve. The state control valve can control the communication state between the spring control port of the flow logic valve, the outlet of the hydraulic pump, and the oil tank.

[0016] According to a hydraulic control system provided by the present invention, the state control valve includes an auxiliary connection position and an auxiliary cut-off position. In the auxiliary connection position, the spring control port of the flow logic valve is connected to the oil tank, and the outlet of the hydraulic pump is connected to the auxiliary power execution unit through the flow logic valve. In the auxiliary cut-off position, the spring control port of the flow logic valve is connected to the outlet of the hydraulic pump, and the outlet of the hydraulic pump is cut off from the auxiliary power execution unit through the flow logic valve.

[0017] According to a hydraulic control system provided by the present invention, the auxiliary power execution unit includes a hydraulic motor and a directional control valve.

[0018] The directional control valve is connected to the outlet of the flow logic valve, the oil tank, and the first and second inlet / outlet ports of the hydraulic motor. The directional control valve controls the communication status between the first and second inlet / outlet ports of the hydraulic motor and the outlet of the flow logic valve and the oil tank.

[0019] According to a hydraulic control system provided by the present invention, the auxiliary power execution unit further includes a shuttle valve, a floating control valve, and a floating logic valve.

[0020] The first inlet of the shuttle valve is connected to the first inlet and return ports of the hydraulic motor, and the second inlet of the shuttle valve is connected to the second inlet and return ports of the hydraulic motor. The floating control valve is connected to the outlet of the shuttle valve, the spring control port of the floating logic valve, and the oil tank. The inlet of the floating logic valve is connected to the first inlet and return ports of the hydraulic motor, and the outlet of the floating logic valve is connected to the second inlet and return ports of the hydraulic motor.

[0021] The floating control valve can switch between a floating position and a floating stop position. In the floating position, the spring control port of the floating logic valve is connected to the oil tank. In the floating stop position, the spring control port of the floating logic valve is connected to the outlet of the shuttle valve.

[0022] According to a hydraulic control system provided by the present invention, a first overload relief valve is installed between the first inlet and return ports of the hydraulic motor and the oil tank, and a second overload relief valve is installed between the second inlet and return ports of the hydraulic motor and the oil tank.

[0023] A first replenishing check valve is installed between the first inlet and return port of the hydraulic motor and the oil tank, and a second replenishing check valve is installed between the second inlet and return port of the hydraulic motor and the oil tank.

[0024] According to a second aspect of the present invention, a working machine is provided, including a hydraulic control system as described above.

[0025] According to a third aspect of the present invention, a power output control method is provided, applied to the operating machinery described above, comprising the following steps:

[0026] Based on the transmission ratio of the operating machinery's transmission structure, adjust the set pressure of the pressure regulating control valve group;

[0027] The flow rate of the hydraulic pump is adjusted based on the rotational speed of the front drive axle.

[0028] The hydraulic control system provided by this invention includes an oil source, a pressure regulating valve group, an auxiliary power actuator, an auxiliary power control valve group, a transmission ratio detection device, and a control device. The oil source supplies oil to the auxiliary power actuator. The auxiliary power control valve group is connected between the oil source and the auxiliary power actuator and is used to control the connection state between them, enabling the auxiliary power actuator to operate in the forward, reverse, or stop operation. The pressure regulating valve group is connected to the oil source and is used to regulate the output pressure of the oil source, or in other words, to regulate the working pressure of the hydraulic control system. The transmission ratio detection device can detect the transmission ratio of the working machinery's transmission structure. For example, this transmission ratio is the ratio between the engine speed and the front axle speed in the front drive axle. The control device can receive the transmission ratio detected by the transmission ratio detection device and, based on this transmission ratio, can control the operating state of the auxiliary power control valve group and adjust the set pressure of the pressure regulating valve group.

[0029] For example, in actual operation, when the transmission ratio is within the normal threshold, the control device controls the operating state of the auxiliary power control valve group to stop the auxiliary power actuator from working, thus ceasing to provide auxiliary driving force to the working machinery. When the transmission ratio is outside the normal threshold, the control device controls the operating state of the auxiliary power control valve group to start the auxiliary power actuator, providing auxiliary driving force to the working machinery. The control device can also adjust the set pressure of the pressure regulating valve group based on the degree to which the transmission ratio exceeds the normal threshold, thereby adjusting the output pressure of the oil source. In other words, in this hydraulic control system, the output pressure of the oil source can be adjusted according to the actual working conditions.

[0030] With this structural design, the control device can not only control the activation state of the auxiliary power actuator through the auxiliary power control valve group, but also flexibly adjust the set pressure of the pressure regulating valve group based on the transmission speed ratio, thereby flexibly controlling the output pressure of the oil source. This not only improves the actual working efficiency of the hydraulic control system, but also reduces energy waste caused by the hydraulic control system during operation. Attached Figure Description

[0031] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a system schematic diagram of the hydraulic control system provided by the present invention;

[0033] Figure 2This is a flowchart of the power output control method provided by the present invention;

[0034] Figure label:

[0035] 110. Hydraulic pump; 120. Oil tank; 210. Electro-proportional relief valve; 220. Relief logic valve; 300. Auxiliary power actuator; 310. Hydraulic motor; 320. Directional control valve; 330. Shuttle valve; 340. Floating control valve; 350. Floating logic valve; 361. First overload relief valve; 362. Second overload relief valve; 371. First replenishing check valve; 372. Second replenishing check valve; 400. Auxiliary power control valve assembly; 410. Flow logic valve; 420. Status control valve. Detailed Implementation

[0036] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0037] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, 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 the embodiments of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0039] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] In the description of this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer. 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The following is combined with Figure 1 and Figure 2 This invention describes a hydraulic control system, a working machine, and a power output control method provided by embodiments of the present invention. It should be understood that the following description is merely an illustrative embodiment of the invention and does not constitute any particular limitation on the invention.

[0042] An embodiment of the first aspect of the present invention provides a hydraulic control system, such as Figure 1 As shown, the hydraulic control system includes:

[0043] Oil source;

[0044] The pressure regulating valve assembly is connected to the oil source and is used to regulate the output pressure of the oil source;

[0045] The auxiliary power actuator 300 is used to connect to the rear drive axle of the operating machinery;

[0046] The auxiliary power control valve assembly 400 is connected between the oil source and the auxiliary power actuator 300 and is used to control the connection status between the oil source and the auxiliary power actuator 300.

[0047] Transmission ratio detection device, used to detect the transmission ratio of the transmission structure of working machinery;

[0048] The control device is connected to the transmission ratio detection device, the auxiliary power control valve group 400, and the pressure regulating valve group, and is used to adjust the working state of the auxiliary power control valve group 400 and the set pressure of the pressure regulating valve group based on the detection results of the transmission ratio detection device.

[0049] The hydraulic control system provided by this invention includes an oil source, a pressure regulating valve assembly, an auxiliary power execution unit 300, an auxiliary power control valve assembly 400, a transmission ratio detection device, and a control device. The oil source supplies oil to the auxiliary power execution unit 300. The auxiliary power control valve assembly 400 is connected between the oil source and the auxiliary power execution unit 300 and is used to control the connection state between them, enabling the auxiliary power execution unit 300 to operate in the forward direction, reverse direction, or stop operating. The pressure regulating valve assembly is connected to the oil source and is used to regulate the output pressure of the oil source, or in other words, to regulate the working pressure of the hydraulic control system. The transmission ratio detection device can detect the transmission ratio of the working machinery's transmission structure. For example, this transmission ratio is the ratio between the engine speed and the front axle speed in the front drive axle. The control device can receive the transmission ratio detected by the transmission ratio detection device and, based on this transmission ratio, can control the operating state of the auxiliary power control valve assembly 400 and adjust the set pressure of the pressure regulating valve assembly.

[0050] For example, in actual operation, when the transmission ratio is within the normal threshold, the control device controls the operating state of the auxiliary power control valve group 400 to stop the auxiliary power actuator 300 from working, thus ceasing to provide auxiliary driving force to the working machinery. When the transmission ratio is outside the normal threshold, the control device controls the operating state of the auxiliary power control valve group 400 to start the auxiliary power actuator 300, providing auxiliary driving force to the working machinery. The control device can also adjust the set pressure of the pressure regulating valve group based on the degree to which the transmission ratio exceeds the normal threshold, thereby adjusting the output pressure of the oil source. In other words, in this hydraulic control system, the output pressure of the oil source can be adjusted according to actual working conditions.

[0051] With this structural design, the control device can not only control the activation state of the auxiliary power actuator 300 through the auxiliary power control valve group 400, but also flexibly adjust the set pressure of the pressure regulating valve group based on the transmission speed ratio, thereby flexibly controlling the output pressure of the oil source. This not only improves the actual working efficiency of the hydraulic control system but also reduces energy waste during operation.

[0052] In one embodiment of the present invention, the pressure regulating valve assembly includes an electro-proportional relief valve 210 and a relief logic valve 220. The oil source includes a hydraulic pump 110 and an oil tank 120.

[0053] The inlet of hydraulic pump 110 is connected to oil tank 120. The outlet of hydraulic pump 110 is connected to the inlet of electro-proportional relief valve 210. The outlet of electro-proportional relief valve 210 is connected to oil tank 120. The inlet of relief logic valve 220 is connected to the outlet of hydraulic pump 110. The outlet of relief logic valve 220 is connected to oil tank 120. The spring control port of relief logic valve 220 is connected to the inlet of electro-proportional relief valve 210.

[0054] For example, such as Figure 1 As shown, in this embodiment, the inlet of the overflow logic valve 220 is a conical cavity port, the outlet of the overflow logic valve 220 is an annular cavity port, and the spring control port of the overflow logic valve 220 is a spring cavity port. The inlet of the electro-proportional overflow valve 210 is connected to the outlet of the hydraulic pump 110 and the spring control port of the overflow logic valve 220. The inlet of the overflow logic valve 220 is connected to the outlet of the hydraulic pump 110, and the outlet of the overflow logic valve 220 is connected to the oil tank 120. Thus, the electro-proportional overflow valve 210 can control the opening pressure of the overflow logic valve 220. When the pressure output by the hydraulic pump 110 exceeds the set pressure of the electro-proportional overflow valve 210, the excess pressurized oil will overflow into the oil tank 120 through the inlet and outlet of the overflow logic valve 220.

[0055] The transmission ratio detection device may include a first speed sensor, a second speed sensor, and a corresponding calculation module. The first speed sensor detects the engine speed, the second speed sensor detects the front drive axle speed, and the calculation module calculates the transmission ratio based on the engine speed and the front drive axle speed. This calculation module can transmit the transmission ratio to the control device in real time. The control device is connected to the electro-proportional relief valve 210, and controls its set pressure by controlling the control current of the electro-proportional relief valve 210. For example, the control device may have a pre-set correspondence between the transmission ratio and the control current. Thus, the control device can flexibly control the control current of the electro-proportional relief valve 210 based on the real-time detection results of the transmission ratio detection device, thereby changing the output pressure of the hydraulic pump 110.

[0056] In one embodiment of the present invention, the hydraulic control system further includes a speed detection device. The speed detection device is used to detect the speed of the front drive axle of the working machinery. The control device is connected to the speed detection device and the hydraulic pump 110, and the control device is used to control the flow rate of the hydraulic pump 110 based on the detection result of the speed detection device.

[0057] For example, the speed detection device is a speed sensor. The hydraulic pump 110 is an electro-proportional variable pump. The control device changes the flow rate by adjusting the control current of the electro-proportional variable pump. The speed detection device is used to detect the speed of the front drive axle of the operating machinery. Based on the speed detection device, the control device can calculate the required speed of the rear drive axle. For example, the required speed of the rear drive axle is obtained by multiplying the speed of the front drive axle by a corresponding coefficient. This coefficient can be determined according to actual needs; for example, it can be set to 1.1. The control device has a preset correspondence between the rear drive axle speed and the electro-proportional variable pump control current. Therefore, the control device can determine the required speed of the rear drive axle based on the speed of the front drive axle of the operating machinery, and determine the required magnitude of the electro-proportional variable pump control current based on the required speed of the rear drive axle. This allows the speed of the rear drive axle to be precisely adjusted to the target state, preventing the front axle from dragging the rear axle or the front axle from slipping.

[0058] In one embodiment of the present invention, the auxiliary power control valve group 400 includes a flow logic valve 410 and a status control valve 420.

[0059] The inlet of the flow logic valve 410 is connected to the outlet of the hydraulic pump 110. The outlet of the flow logic valve 410 is connected to the auxiliary power actuator 300. The status control valve 420 is connected to the outlet of the hydraulic pump 110, the oil tank 120, and the spring control port of the flow logic valve 410. The status control valve 420 can control the connection status between the spring control port of the flow logic valve 410, the outlet of the hydraulic pump 110, and the oil tank 120.

[0060] Furthermore, in one embodiment of the present invention, the state control valve 420 includes an auxiliary connection position and an auxiliary cut-off position. In the auxiliary connection position, the spring control port of the flow logic valve 410 is connected to the oil tank 120, and the oil outlet of the hydraulic pump 110 is connected to the auxiliary power execution unit 300 through the flow logic valve 410. In the auxiliary cut-off position, the spring control port of the flow logic valve 410 is connected to the oil outlet of the hydraulic pump 110, and the oil outlet of the hydraulic pump 110 is cut off from the auxiliary power execution unit 300 through the flow logic valve 410.

[0061] Specifically, such as Figure 1As shown, in this embodiment, the inlet of the flow logic valve 410 is the port of its annular cavity, the outlet of the flow logic valve 410 is the port of its conical cavity, and the spring control port of the flow logic valve 410 is the port of its spring cavity. For example, the state control valve 420 is a two-position three-way solenoid directional valve, which includes a first working port, a second working port, and a third working port, and can switch between an auxiliary connection position and an auxiliary cut-off position. The first working port is connected to the outlet of the hydraulic pump 110, the second working port is connected to the oil tank 120, and the third working port is connected to the spring control port of the flow logic valve 410. The inlet of the flow logic valve 410 is connected to the outlet of the hydraulic pump 110, and the outlet of the flow logic valve 410 is connected to the auxiliary power execution unit 300.

[0062] Therefore, when the state control valve 420 switches to the auxiliary connection position, the second working port connects to the third working port, that is, the spring control port of the flow logic valve 410 connects to the oil tank 120, and the spring chamber of the flow logic valve 410 connects to the oil tank 120, so that the flow logic valve 410 opens. At this time, the oil output by the hydraulic pump 110 can be delivered to the auxiliary power execution unit 300 through the inlet and outlet of the flow logic valve 410 to drive the auxiliary power execution unit 300 to start. When the state control valve 420 switches to the auxiliary stop position, the first working port connects to the third working port, that is, the spring control port of the flow logic valve 410 connects to the outlet of the hydraulic pump 110, and the oil output by the hydraulic pump 110 can be delivered to the spring chamber of the flow logic valve 410, so that the flow logic valve 410 locks. At this time, the oil output by the hydraulic pump 110 cannot be delivered to the auxiliary power execution unit 300, and the auxiliary power execution unit 300 stops working.

[0063] In one embodiment of the present invention, the auxiliary power execution unit 300 includes a hydraulic motor 310 and a directional control valve 320.

[0064] The directional control valve 320 is connected to the outlet of the flow logic valve 410, the oil tank 120, and the first and second inlet / outlet ports of the hydraulic motor 310. The directional control valve 320 is used to control the connection status between the first and second inlet / outlet ports of the hydraulic motor 310 and the outlet of the flow logic valve 410 and the oil tank 120.

[0065] For example, such as Figure 1As shown, the directional control valve 320 is a three-position four-way directional valve. The four working ports of the three-position four-way directional valve are connected to the outlet of the flow logic valve 410, the oil tank 120, and the first and second inlet / outlet ports of the hydraulic motor 310, respectively. When the outlet of the flow logic valve 410 is connected to the first inlet / outlet port of the hydraulic motor 310 through the directional control valve 320, and the second inlet / outlet port of the hydraulic motor 310 is connected to the oil tank 120 through the directional control valve 320, the hydraulic motor 310 rotates in the forward direction. When the outlet of the flow logic valve 410 is connected to the second inlet / outlet port of the hydraulic motor 310 through the directional control valve 320, and the first inlet / outlet port of the hydraulic motor 310 is connected to the oil tank 120, the hydraulic motor 310 rotates in the reverse direction.

[0066] In one embodiment of the present invention, the auxiliary power execution unit 300 further includes a shuttle valve 330, a floating control valve 340, and a floating logic valve 350.

[0067] The first inlet of the shuttle valve 330 is connected to the first inlet and return ports of the hydraulic motor 310, and the second inlet of the shuttle valve 330 is connected to the second inlet and return ports of the hydraulic motor 310. The floating control valve 340 is connected to the outlet of the shuttle valve 330, the spring control port of the floating logic valve 350, and the oil tank 120. The inlet of the floating logic valve 350 is connected to the first inlet and return ports of the hydraulic motor 310. The outlet of the floating logic valve 350 is connected to the second inlet and return ports of the hydraulic motor 310.

[0068] The floating control valve 340 can switch between a floating position and a floating off position. In the floating position, the spring control port of the floating logic valve 350 is connected to the oil tank 120; in the floating off position, the spring control port of the floating logic valve 350 is connected to the oil outlet of the shuttle valve 330.

[0069] Continue to combine Figure 1 In this embodiment, the inlet of the floating logic valve 350 is the port of its annular cavity, the outlet of the floating logic valve 350 is the port of its conical cavity, and the spring control port of the floating logic valve 350 is the port of its spring cavity. The first and second inlets of the shuttle valve 330 are connected to the first and second inlet / return ports of the hydraulic motor 310, respectively. Since the first and second inlet / return ports of the hydraulic motor 310 are connected to the two working ports of the directional control valve 320, the first and second inlets of the shuttle valve 330 can also be understood as being connected to the two working ports of the directional control valve 320. The floating control valve 340 is a two-position three-way solenoid directional valve. Its three working ports are connected to the outlet of the shuttle valve 330, the oil tank 120, and the spring control port of the floating logic valve 350, respectively.

[0070] When the floating control valve 340 is switched to the floating position, the spring control port of the floating logic valve 350 is connected to the oil tank 120. At this time, the floating logic valve 350 is in the open state, and the pressure at the first and second inlets of the shuttle valve 330 is equal. The pressure at the first and second inlet / return ports of the hydraulic motor 310 is also equal. The hydraulic motor 310 is in a floating state to achieve pressure relief operation. For example, when braking the working machinery, the floating control valve 340 can be switched to the floating position.

[0071] When the floating control valve 340 switches to the floating stop position, the spring control port of the floating logic valve 350 connects to the outlet port of the shuttle valve 330. At this time, the floating logic valve 350 is in the locked state. Because the pressures between the first and second inlets of the shuttle valve 330 are different, a pressure difference exists between the first and second inlet / return ports of the hydraulic motor 310, allowing the hydraulic motor 310 to operate normally.

[0072] In one embodiment of the present invention, such as Figure 1 As shown, a first overload relief valve 361 is installed between the first inlet and return ports of the hydraulic motor 310 and the oil tank 120. A second overload relief valve 362 is installed between the second inlet and return ports of the hydraulic motor 310 and the oil tank 120. Thus, the first overload relief valve 361 and the second overload relief valve 362 can provide overload protection for the forward and reverse rotation operations of the hydraulic motor 310.

[0073] A first replenishing check valve 371 is installed between the first inlet and outlet ports of the hydraulic motor 310 and the oil tank 120. A second replenishing check valve 372 is installed between the second inlet and outlet ports of the hydraulic motor 310 and the oil tank 120. This prevents the hydraulic motor 310 from sucking in cavitation, protecting the hydraulic motor 310 and avoiding the generation of cavitation noise.

[0074] A second aspect of the present invention provides a working machine including a hydraulic control system as described above.

[0075] For example, the aforementioned operating machinery includes cranes.

[0076] It should be noted that the above embodiments are merely illustrative examples of the present invention and do not constitute any limitation on the present invention. In other embodiments of the present invention, the above-mentioned operating machinery may also include excavators, loaders, etc.

[0077] A third aspect of the present invention provides a power output control method, applied to the operating machinery described above, such as... Figure 2 As shown, it includes the following steps:

[0078] Based on the transmission ratio of the operating machinery's transmission structure, adjust the set pressure of the pressure regulating control valve group;

[0079] The flow rate of hydraulic pump 110 is adjusted based on the rotational speed of the front drive axle.

[0080] Specifically, the pressure regulating control valve assembly includes an electro-proportional relief valve 210 and a relief logic valve 220. The inlet of the electro-proportional relief valve 210 is connected to the outlet of the hydraulic pump 110 and the spring control port of the relief logic valve 220. The inlet of the relief logic valve 220 is connected to the outlet of the hydraulic pump 110, and the outlet of the relief logic valve 220 is connected to the oil tank 120. Thus, the electro-proportional relief valve 210 can control the opening pressure of the relief logic valve 220. When the pressure output by the hydraulic pump 110 exceeds the set pressure of the electro-proportional relief valve 210, the excess pressurized oil overflows into the oil tank 120 through the inlet and outlet of the relief logic valve 220.

[0081] The transmission ratio detection device can detect the transmission ratio of the transmission structure of the working machinery. The control device is connected to the electro-proportional relief valve 210 and the transmission ratio detection device. The control device controls the set pressure of the electro-proportional relief valve 210 by controlling the magnitude of its control current. The control device has a pre-set correspondence between the transmission ratio and the control current. Therefore, during operation, the control device flexibly controls the magnitude of the control current of the electro-proportional relief valve 210 based on the real-time detection results of the transmission ratio detection device, thereby changing the output pressure of the hydraulic pump 110. This control method can improve the working efficiency of the hydraulic control system and reduce energy waste caused by the hydraulic control system during operation.

[0082] Hydraulic pump 110 is an electro-proportional variable pump. The control device adjusts the control current of the electro-proportional variable pump to change its flow rate. A speed detection device is used to detect the speed of the front drive axle of the machine. Based on the speed detection device, the control device can calculate the required speed of the rear drive axle. The control device has a preset correspondence between the rear drive axle speed and the control current of the electro-proportional variable pump. Therefore, the control device can determine the required speed of the rear drive axle based on the speed of the front drive axle, and determine the required magnitude of the control current of the electro-proportional variable pump based on the speed requirement of the rear drive axle. This allows the rear drive axle speed to be precisely adjusted to the target state, preventing the front axle from dragging the rear axle or the front axle from slipping.

[0083] Furthermore, since the machine includes the hydraulic control system described above, or uses the power control method described above for power output control, it also possesses the advantages described above.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic control system, characterized in that, include: Oil source; A pressure regulating valve assembly is connected to the oil source and is used to regulate the output pressure of the oil source; Auxiliary power actuator, used to connect to the rear drive axle of the operating machinery; An auxiliary power control valve assembly is connected between the oil source and the auxiliary power actuator and is used to control the connection state between the oil source and the auxiliary power actuator. A transmission ratio detection device is used to detect the transmission ratio of the transmission structure of a working machine. The transmission ratio is the ratio between the engine speed in the front drive axle and the front axle speed. A control device is connected to the transmission ratio detection device, the auxiliary power control valve group, and the pressure regulating valve group, and is used to adjust the working state of the auxiliary power control valve group and the set pressure of the pressure regulating valve group based on the detection result of the transmission ratio detection device. When the transmission ratio is within the normal threshold, the control device controls the working state of the auxiliary power control valve group to stop the auxiliary power actuator from working, thereby ceasing to provide auxiliary driving force to the working machinery; when the transmission ratio is outside the normal threshold, the control device controls the working state of the auxiliary power control valve group to start the auxiliary power actuator from working, thereby providing auxiliary driving force to the working machinery; the control device can also adjust the set pressure of the pressure regulating valve group based on the degree to which the transmission ratio exceeds the normal threshold, thereby adjusting the output pressure of the oil source.

2. The hydraulic control system according to claim 1, characterized in that, The pressure regulating valve group includes an electro-proportional relief valve and a relief logic valve, and the oil source includes a hydraulic pump and an oil tank. The inlet of the hydraulic pump is connected to the oil tank, the outlet of the hydraulic pump is connected to the inlet of the electro-proportional relief valve, the outlet of the electro-proportional relief valve is connected to the oil tank, the inlet of the relief logic valve is connected to the outlet of the hydraulic pump, the outlet of the relief logic valve is connected to the oil tank, and the spring control port of the relief logic valve is connected to the inlet of the electro-proportional relief valve.

3. The hydraulic control system according to claim 2, characterized in that, The hydraulic control system further includes a speed detection device for detecting the speed of the front drive axle of the machine. The control device is connected to the speed detection device and the hydraulic pump, and the control device controls the flow rate of the hydraulic pump based on the detection result of the speed detection device.

4. The hydraulic control system according to claim 3, characterized in that, The auxiliary power control valve group includes a flow logic valve and a status control valve; The inlet of the flow logic valve is connected to the outlet of the hydraulic pump, the outlet of the flow logic valve is connected to the auxiliary power execution unit, the state control valve is connected to the outlet of the hydraulic pump, the oil tank, and the spring control port of the flow logic valve, and the state control valve can control the connection state between the spring control port of the flow logic valve, the outlet of the hydraulic pump, and the oil tank.

5. The hydraulic control system according to claim 4, characterized in that, The state control valve includes an auxiliary connection position and an auxiliary cut-off position. In the auxiliary connection position, the spring control port of the flow logic valve is connected to the oil tank, and the outlet of the hydraulic pump is connected to the auxiliary power execution unit through the flow logic valve. In the auxiliary cut-off position, the spring control port of the flow logic valve is connected to the outlet of the hydraulic pump, and the outlet of the hydraulic pump is cut off from the auxiliary power execution unit through the flow logic valve.

6. The hydraulic control system according to claim 4 or 5, characterized in that, The auxiliary power actuator includes a hydraulic motor and a directional control valve; The directional control valve is connected to the outlet of the flow logic valve, the oil tank, the first inlet and return oil port and the second inlet and return oil port of the hydraulic motor. The directional control valve is used to control the communication status between the first inlet and return oil port and the second inlet and return oil port of the hydraulic motor and the outlet of the flow logic valve and the oil tank.

7. The hydraulic control system according to claim 6, characterized in that, The auxiliary power actuator also includes a shuttle valve, a floating control valve, and a floating logic valve; The first oil inlet of the shuttle valve is connected to the first oil inlet and return port of the hydraulic motor, and the second oil inlet of the shuttle valve is connected to the second oil inlet and return port of the hydraulic motor. The floating control valve is connected to the oil outlet of the shuttle valve, the spring control port of the floating logic valve, and the oil tank. The oil inlet of the floating logic valve is connected to the first oil inlet and return port of the hydraulic motor, and the oil outlet of the floating logic valve is connected to the second oil inlet and return port of the hydraulic motor. The floating control valve can switch between a floating position and a floating stop position. In the floating position, the spring control port of the floating logic valve is connected to the oil tank; in the floating stop position, the spring control port of the floating logic valve is connected to the outlet of the shuttle valve.

8. The hydraulic control system according to claim 7, characterized in that, A first overload relief valve is installed between the first inlet and return port of the hydraulic motor and the oil tank, and a second overload relief valve is installed between the second inlet and return port of the hydraulic motor and the oil tank. A first replenishing check valve is installed between the first inlet and return port of the hydraulic motor and the oil tank, and a second replenishing check valve is installed between the second inlet and return port of the hydraulic motor and the oil tank.

9. A type of operating machinery, characterized in that, Includes a hydraulic control system according to any one of claims 1 to 8.

10. A power output control method, characterized in that, The application of the working machinery according to claim 9 includes the following steps: Based on the transmission ratio of the operating machinery's transmission structure, adjust the set pressure of the pressure regulating control valve group; The flow rate of the hydraulic pump is adjusted based on the rotational speed of the front drive axle.

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