A load-sensitive split-flow and merging control valve for dual quantitative pumps

Abstract

This invention discloses a dual fixed-displacement pump load-sensitive flow splitting and merging control valve, comprising a valve body. The valve body houses a three-way flow valve, an electromagnetic proportional unloading valve, and a merging check valve. The valve body has a first inlet, a second inlet, an outlet, and a return port. The first and second inlets are connected to the inlet of the merging check valve. The inlet of the three-way flow valve and the outlet of the valve body are connected to the outlet of the merging check valve. The return port of the three-way flow valve is connected to the return port of the valve body. The inlet of the electromagnetic proportional unloading valve is connected to the second inlet of the valve body, and the outlet of the electromagnetic proportional unloading valve is connected to the return port of the valve body. The electronic control terminal of the electromagnetic proportional unloading valve is connected to the vehicle controller. This invention is mounted on the vehicle chassis, meaning the three-way flow valve is integrated into the chassis, reducing noise. Furthermore, the electromagnetic proportional unloading valve achieves unloading of the fixed-displacement pump, thereby reducing energy output and fuel consumption.

Description

Technical Field

[0001] This invention relates to the field of dual quantitative pump load-sensitive multi-way valve technology, specifically a dual quantitative pump load-sensitive diversion and merging control valve connected to a dual quantitative pump load-sensitive multi-way valve. Background Technology

[0002] Currently, most hydraulic systems in truck cranes still use fixed displacement pumps (gear pumps) in conjunction with multi-way valves as the power source and control elements. These systems are characterized by low cost and high reliability. The performance of the multi-way valve directly determines the safety of the entire system or the entire machine operation. Currently, 25-ton truck cranes mainly use load-sensitive multi-way valves to ensure the combined actions of various actuators, with a relief valve to guarantee a certain on-demand flow diversion capacity. However, this inevitably leads to fixed energy losses and system heat generation. Because truck cranes are required to maintain continuous power during lifting, a large proportion of operations are in standby mode. This standby (no action, no overflow) state generates significant energy loss, and the overflow noise directly affects the health and safety of the operator.

[0003] In load-sensitive multi-way valves, all valve stems are in a closed-core system in the neutral position. In this state, when in standby mode, the oil output from the fixed displacement pump will not have a return path; it can only be supplied through overflow or by reducing the amount of oil entering the valve. See [link / reference]. Figure 1 In a dual fixed displacement pump load-sensitive multi-way valve, since the oil output of the fixed displacement pump is fixed, excess oil needs to overflow in the neutral position. However, the overflow valve 01 is opened under high pressure. Therefore, high pressure overflow in the neutral position will cause a large amount of energy loss and generate a large amount of heat, leading to system overheating. In order to reduce energy loss and adverse effects, a built-in three-way flow valve 02 is added to the dual fixed displacement pump load-sensitive multi-way valve. In the neutral position, a lower pressure is set, generally 3 MPa, so that a large amount of oil output by the fixed displacement pump overflows through the built-in three-way flow valve 02 under this pressure.

[0004] See Figure 2 In order to meet the requirements of compound actions and reduce some unnecessary flow, there are also load-sensitive multi-way valves with flow splitting and merging modes. That is, a merging link 03 is added to the load-sensitive multi-way valve to control the flow splitting and merging, so as to reduce flow loss when high-speed movement is not required.

[0005] but Figure 1 and Figure 2The two structures shown have the following disadvantages: 1. The built-in three-way flow valve 02 in the load-sensitive multi-way valve generates significant noise during operation due to the large flow rate. Furthermore, the load-sensitive multi-way valve is very close to the driver's cab, and since the truck crane is mostly in standby (no overflow) mode, the overflow noise is bothersome to the driver and passengers. 2. Because the built-in three-way flow valve 02 is integrated into the load-sensitive multi-way valve, subsequent debugging and maintenance are very difficult. 3. To achieve flow splitting and merging through the load-sensitive multi-way valve, a merging connector 03 needs to be configured within the load-sensitive multi-way valve, along with two independent built-in three-way flow valves 02 and overflow valves. The module consisting of valve 01 is designed to ensure load-sensitive control of each action in the diversion state. This results in the load-sensitive multi-way valve being too large, difficult to arrange, and significantly increasing the cost. At the same time, during the merging process, due to the presence of two independent modules consisting of built-in three-way flow valve 02 and overflow valve 01, pressure interference can occur when the pressure adjustment is inconsistent. 4. Neither of the two structures can achieve the problem of changing the total (displacement) flow of the dual fixed displacement pumps in standby (no overflow) and load operation, which inevitably leads to fixed ineffective energy loss. It is impossible to unload a single fixed displacement pump and reduce energy loss when operating without overflow. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a dual fixed displacement pump load-sensitive flow control valve, which is installed on the vehicle chassis and integrates a three-way flow valve and an electromagnetic proportional unloading valve. This allows the three-way flow valve to be connected to the dual fixed displacement pump load-sensitive multi-way valve independently, thereby reducing noise. Furthermore, the electromagnetic proportional unloading valve enables the fixed displacement pump output to be unloaded and returned to the fuel tank, thereby reducing energy output, energy consumption, and fuel consumption.

[0007] The technical solution of this invention is as follows:

[0008] A dual-quantitative pump load-sensitive flow splitting and merging control valve includes a valve body, which houses a three-way flow valve, an electromagnetic proportional unloading valve, and a merging check valve. The valve body has a first oil inlet, a second oil inlet, an oil outlet, and a return oil outlet. The first and second oil inlets on the valve body are both connected to the inlet of the merging check valve. The inlet of the three-way flow valve and the outlet on the valve body are both connected to the outlet of the merging check valve. The return oil outlet of the three-way flow valve is connected to the return oil outlet on the valve body. The inlet of the electromagnetic proportional unloading valve is connected to the second oil inlet on the valve body. The outlet of the electromagnetic proportional unloading valve is connected to the return oil outlet on the valve body. The electronic control terminal of the electromagnetic proportional unloading valve is connected to the vehicle controller.

[0009] The valve body is provided with a load feedback port, and the feedback input port of the three-way flow valve is connected to the load feedback port on the valve body.

[0010] The merging check valve includes a first check valve and a second check valve. The oil inlet of the first check valve is connected to the first oil inlet on the valve body, and the oil inlet of the second check valve is connected to the second oil inlet on the valve body. The oil outlets of the first check valve and the second check valve are connected to each other as the oil outlet of the merging check valve.

[0011] The electromagnetic proportional unloading valve includes an electromagnetic proportional valve and a hydraulic control valve. The energizing coil of the electromagnetic proportional valve is connected to the vehicle controller. The oil inlet of the electromagnetic proportional valve is connected to the oil outlet of the confluence check valve. The oil outlet of the electromagnetic proportional valve is connected to the control oil port of the hydraulic control valve. The oil inlet of the hydraulic control valve is connected to the second oil inlet on the valve body. The oil outlet of the hydraulic control valve is connected to the return oil port on the valve body.

[0012] Advantages of this invention:

[0013] (1) The present invention separates the three-way flow valve from the dual quantitative pump load-sensitive multi-way valve and sets the present invention at the bottom of the U-shaped frame of the car chassis, away from the driver’s cab. The noise generated by the three-way flow valve is masked by the noise generated by the engine and motor, and will not cause trouble to the driver and passengers.

[0014] (2) By adding a merging check valve, the present invention can output the combined oil flow from the first oil outlet and the second oil outlet connected to the dual quantitative pump on the valve body to the working mechanism.

[0015] (3) The present invention is equipped with an electromagnetic proportional unloading valve, which can realize the diversion function of the dual fixed displacement pump with small impact, that is, the oil output from the second oil outlet on the valve body is directly unloaded from the electromagnetic proportional unloading valve to the oil tank slowly. At this time, the first oil outlet on the valve body is always outputting a fixed amount of oil to the working mechanism, thereby reducing the displacement of the dual fixed displacement pump. At the same time, the impact during the switching of diversion and merging is reduced by the control of the electromagnetic proportional unloading valve. Meanwhile, the unloading of the electromagnetic proportional unloading valve also further reduces the return oil flow of the three-way flow valve, greatly reducing noise.

[0016] (4) The electromagnetic proportional unloading valve of the present invention is connected to the vehicle controller, so that the vehicle controller responds to the handle action in a timely manner and judges that the current working condition is that the flow demand is small when the boom is retracted, the luffing is lowered, and the auxiliary winding is micro-moved. It controls the electromagnetic proportional unloading valve to unload the oil from the second oil outlet on the valve body to the oil tank and controls the maximum speed of the engine. After the standby time exceeds the set time, the idle speed is automatically reduced to achieve the purpose of saving energy and fuel. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an existing dual fixed displacement pump load-sensitive multi-way valve.

[0018] Figure 2 This is a schematic diagram of the existing dual fixed displacement pump load-sensitive split / combination multi-way valve.

[0019] Figure 3 This is a schematic diagram of the structure of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the present invention connected to a dual quantitative pump load-sensitive multi-way valve.

[0021] Reference numerals: 01-Relief valve, 02-Built-in three-way flow valve, 03-Combined flow valve, 11-Three-way flow valve, 12-First check valve, 13-Second check valve, 14-Solenoid proportional valve, 15-Hydraulic control valve. Detailed Implementation

[0022] 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, and 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.

[0023] See Figure 3 A dual-quantitative pump load-sensitive flow splitting and merging control valve includes a valve body. The valve body houses a three-way flow valve 11, an electromagnetic proportional unloading valve, and a merging check valve. The merging check valve includes a first check valve 12 and a second check valve 13. The valve body is provided with a first inlet P1, a second inlet P2, an outlet P, a return port T, and a load feedback port LS. The inlet of the first check valve 12 is connected to the first inlet P1 on the valve body, and the inlet of the second check valve 13 is connected to the second inlet P2 on the valve body. The outlets of the first check valve 12 and the second check valve 13 are interconnected as the outlet of the merging check valve. The inlet of the three-way flow valve 11... The oil port and the oil outlet P on the valve body are both connected to the oil outlet of the merging check valve. The oil return port of the three-way flow valve 11 is connected to the oil return port T on the valve body. The feedback input port of the three-way flow valve 11 is connected to the load feedback port LS on the valve body. The electromagnetic proportional unloading valve includes an electromagnetic proportional valve 14 and a hydraulic control valve 15. The energizing coil of the electromagnetic proportional valve 14 is connected to the vehicle controller. The oil inlet of the electromagnetic proportional valve 14 is connected to the oil outlet of the merging check valve. The oil outlet of the electromagnetic proportional valve 14 is connected to the control oil port of the hydraulic control valve 15. The oil inlet of the hydraulic control valve 15 is connected to the second oil inlet P2 on the valve body. The oil outlet of the hydraulic control valve 15 is connected to the oil return port T on the valve body.

[0024] See Figure 4The dual fixed displacement pump load-sensitive multi-way valve is equipped with only an overflow valve 01, and the built-in three-way flow valve 02 is removed. The hydraulic power source is a double gear pump with a displacement of 63+50ml / r. The return port T on the valve body of the dual fixed displacement pump load-sensitive split and merge control valve is connected to the oil tank. The first inlet port P1 on the valve body is connected to the 50ml / r displacement fixed displacement pump. The second inlet port P2 on the valve body is connected to the 63ml / r displacement fixed displacement pump. The outlet port P on the valve body is connected to the inlet port of the dual fixed displacement pump load-sensitive multi-way valve. The load feedback output port of the dual fixed displacement pump load-sensitive multi-way valve is connected to the load feedback port LS on the valve body.

[0025] When the fixed displacement pump with a displacement of 50 ml / r is working, the 50 ml / r fixed displacement pump is unloaded and the flow is regulated by the three-way flow valve 11. When the double gear pump with a displacement of 63+50 ml / r is working, the double gear pump with a displacement of 63+50 ml / r is merged by the flow-merging check valve and then unloaded and the flow is regulated by the three-way flow valve 11. Under this condition, the idle power demand is low, avoiding the problem of engine stalling at low speeds. At the same time, the noise value of the flow of the three-way flow valve 11 is reduced. Even when the two fixed displacement pumps are working at the same time, the overflow noise generated is completely masked by the engine and cannot be detected.

[0026] Standby energy-saving mode: When idling and the driver does not operate the lever, after the lever returns to the neutral position and remains there for a certain period of time (10 seconds), the default working state is no longer activated. The vehicle controller will output a PWM signal to the solenoid proportional valve 14, which will close. The oil flowing out of the confluence check valve outlet enters the control port of the hydraulic control valve 15 through the solenoid proportional valve 14, causing the hydraulic control valve 15 to close. The load output by the 63ml / r displacement fixed pump through the second oil inlet P2 is unloaded back to the oil tank through the hydraulic control valve 15, reducing energy consumption. At the same time, the engine idle speed is reduced by 100-200n / min, reducing fuel consumption.

[0027] Automatic unloading mode: When the driver performs one or more actuator operations, the vehicle controller learns that the vehicle is in a low-flow-demand condition such as standby, boom retraction, or luffing. The vehicle controller outputs a PWM signal to the solenoid proportional valve 14, which is energized and closes, causing the hydraulic control valve 15 to close. The 63ml / r displacement fixed pump completes the unloading operation, thereby reducing the flow output. At the same time, the torque acting on the engine also decreases. Thus, the engine speed can be reduced without the vehicle stalling. Ultimately, the dual variable flow speed regulation function of engine speed and fixed pump displacement is realized, and the maximum energy-saving control of the vehicle is achieved.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-displacement pump load-sensitive flow splitting and merging control valve, characterized in that: It includes a valve body, which houses a three-way flow valve, an electromagnetic proportional unloading valve, and a merging check valve. The valve body is equipped with a first oil inlet, a second oil inlet, an oil outlet, and a return oil outlet. The first and second oil inlets on the valve body are connected to the oil inlet of the merging check valve. The oil inlet of the three-way flow valve and the oil outlet on the valve body are connected to the oil outlet of the merging check valve. The return oil outlet of the three-way flow valve is connected to the return oil outlet on the valve body. The oil inlet of the electromagnetic proportional unloading valve is connected to the second oil inlet on the valve body. The oil outlet of the electromagnetic proportional unloading valve is connected to the return oil outlet on the valve body. The electronic control terminal of the electromagnetic proportional unloading valve is connected to the vehicle controller. The valve body is provided with a load feedback port, and the feedback input port of the three-way flow valve is connected to the load feedback port on the valve body. The electromagnetic proportional unloading valve includes an electromagnetic proportional valve and a hydraulic control valve. The energizing coil of the electromagnetic proportional valve is connected to the vehicle controller. The oil inlet of the electromagnetic proportional valve is connected to the oil outlet of the confluence check valve. The oil outlet of the electromagnetic proportional valve is connected to the control oil port of the hydraulic control valve. The oil inlet of the hydraulic control valve is connected to the second oil inlet on the valve body. The oil outlet of the hydraulic control valve is connected to the return oil port on the valve body.

2. The dual quantitative pump load-sensitive flow splitting and merging control valve according to claim 1, characterized in that: The merging check valve includes a first check valve and a second check valve. The oil inlet of the first check valve is connected to the first oil inlet on the valve body, and the oil inlet of the second check valve is connected to the second oil inlet on the valve body. The oil outlets of the first check valve and the second check valve are connected to each other as the oil outlet of the merging check valve.

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