Electro-hydraulic composite power control structure for hydraulic pump

Abstract

The utility model provides an electro-hydraulic composite power control structure for a hydraulic pump, which comprises a valve body, a valve sleeve is arranged in the valve body, a slidable top core and a valve core are arranged in the valve sleeve, an oil cavity in the valve sleeve is divided into a left end oil cavity and a middle oil cavity by the top core and the valve core, and a right end oil cavity is arranged on the inner wall of the right end of the valve sleeve; the upper end of the valve body is provided with an oil channel for introducing electromagnetic valve pressure oil and an oil channel for pumping pressure oil, the oil channels are respectively connected with inlets of the electromagnetic valve pressure oil channel and an oil drainage channel, and outlets of the electromagnetic valve pressure oil channel and the oil drainage channel are connected with a control electromagnetic valve; an electromagnetic valve pressure oil channel and a pump pressure oil channel are introduced to enable pressure oil to act on the ejector core and the valve element respectively, the ejector core and the valve element are pushed to move, and a plug used for limiting the ejector core is arranged at a counter bore in the left end of the valve sleeve. Belongs to the technical field of hydraulic pump control structure optimization. According to the utility model, the pressure of the electromagnetic valve is added, so that the originally required pump output pressure is reduced, and the power reduction requirement of the hydraulic pump is met.

Description

Technical Field

[0001] The utility model relates to an electro-hydraulic composite power control structure for a hydraulic pump, belonging to the technical field of hydraulic pump control structure optimization. Background Art

[0002] The variable of the hydraulic pump is to adapt to different working conditions by adjusting the displacement. At present, well-known hydraulic component manufacturers at home and abroad generally use a closed variable system consisting of a constant power variable pump and a quantitative motor when designing hydraulic drive systems. It can make the hydraulic pump output a corresponding displacement as the load changes, so that the engine power can be fully utilized and energy loss can be reduced. However, the constant power setting value of the constant power variable pump currently on the market is usually a constant value, which is a fixed variable method (the pressure-flow hyperbola shape is fixed), that is, the product of the system pressure and the output flow of the plunger pump (the output power of the pump) is approximately a certain value. As the working environment becomes more and more complex, a single power setting value can no longer meet the user's needs in terms of efficiency and energy consumption.

[0003] Therefore, the art urgently needs to develop an optimized structure suitable for multiple working conditions that can realize power shear control of hydraulic pumps, which is of great significance to improving the control performance and diversification of hydraulic pumps. Summary of the invention

[0004] The utility model aims to solve the problem that the prior art lacks a structure for realizing power shear control of a hydraulic pump.

[0005] In order to achieve the purpose of solving the above-mentioned problems, the technical solution adopted by the utility model is to provide an electro-hydraulic composite power control structure for a hydraulic pump, including a valve body, a valve sleeve is arranged inside the valve body, the left and right ends of the valve sleeve are pressed in the valve body by springs, a slidable top core and a valve core are arranged inside the valve sleeve, the top core and the valve core divide the oil chamber inside the valve sleeve into a left end oil chamber and a middle oil chamber, and a right end oil chamber is arranged on the inner wall of the right end of the valve sleeve; a solenoid valve for controlling power is fixed on the lower end surface of the valve body, an oil passage for introducing solenoid valve pressure oil and pump pressure oil is arranged inside the lower end of the valve body, and the oil passage for introducing solenoid valve pressure oil and pump pressure oil is respectively connected to the solenoid valve pressure oil passage and the oil leakage passage outlet arranged on the solenoid valve, the oil passage for introducing solenoid valve pressure oil and pump pressure oil makes the pressure oil act on the top core and the valve core respectively, and pushes the top core and the valve core to move, and a plug for limiting the top core is arranged at the countersunk hole at the left end of the valve sleeve, and the solenoid valve controls the output of different solenoid valve pressure oils through electrical signals, and works together with the pump pressure oil output by the hydraulic pump to realize the hydraulic pump variable.

[0006] Preferably, the left end of the valve sleeve is always tangent to the feedback pin through the screw plug, the spring seat and the left end spring. When the spring stiffness is set to the minimum displacement, the rightward force generated by the spring is greater than the value obtained by the maximum solenoid valve pressure acting on the plug to generate a leftward force and the maximum pump pressure acting on the valve sleeve to generate a leftward force.

[0007] Preferably, the plug is pressed into the valve sleeve by a left end spring, and the plug diameter is larger than the top core diameter.

[0008] Preferably, the middle oil chamber in the valve sleeve is provided with a channel communicating with the valve sleeve oil drain channel.

[0009] Preferably, the left end of the top core is a spherical structure to prevent the top core from adhering to the plug and control the oil from entering so that the top core cannot be pushed to move, causing the top core to fail in function.

[0010] Preferably, the solenoid valve is fixed to the lower end of the valve body by screws.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] 1. The purpose of the utility model is to solve the problem that the constant power setting value of the hydraulic pump is fixed and single, and cannot meet the diversified needs of users in terms of efficiency and energy consumption. By optimizing the control structure of the hydraulic pump, the control unit has the function of traditional hydraulic control, and is combined with a more sensitive electrical signal control. By loading the solenoid valve current, the solenoid valve outputs different pressure oils, and the solenoid valve pressure oil and the pump pressure oil work together to realize the hydraulic pump variable. Compared with the original single pump pressure oil to control the hydraulic pump variable, the utility model adds the solenoid valve pressure, which reduces the original required pump output pressure and realizes the power reduction demand of the hydraulic pump. The solenoid valve loading current is set according to the actual needs of the customer, and different constant power setting values ​​are switched to meet the comprehensive efficiency and energy consumption requirements of different users and multiple working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the existing hydraulic pump power control structure.

[0014] Figure 2 This is a schematic diagram of the electric-hydraulic composite power control structure of the hydraulic pump of the utility model.

[0015] Figure 3 This is a schematic diagram of the valve sleeve change structure of the utility model.

[0016] Figure 4 This is the schematic diagram of the electro-hydraulic composite power control structure of the hydraulic pump of the utility model.

[0017] Figure numerals: 1. valve body; 2. spring; 3. plug; 4. left end oil chamber; 5. top core; 6. middle oil chamber; 7. right end oil chamber; 8. valve core; 9. solenoid valve pressure oil channel; 10. oil drain channel; 11. solenoid valve; 12. valve sleeve. DETAILED DESCRIPTION

[0018] In order to make the present invention more clearly understood, a preferred embodiment is described in detail with reference to the accompanying drawings as follows:

[0019] like Figure 1 As shown in FIG. 3 , the technical solution adopted by the utility model is to provide an electro-hydraulic composite power control structure for a hydraulic pump, including a valve body 1, a valve sleeve 12, a top core 5, a plug 3, a solenoid valve 11 and a spring 2;

[0020] The lower end surface of the valve body 1 is connected to the solenoid valve 11, and the two oil passages at the lower end of the valve body are connected to the solenoid valve pressure oil passage 9 and the oil leakage passage 10 respectively; a valve sleeve 12 is arranged in the valve body 1, and the two ends of the valve sleeve 12 are pressed by springs; a slidable top core 5 and a valve core 8 are arranged in the valve sleeve; the valve sleeve is provided with oil passages for introducing the solenoid valve pressure oil and the pump pressure oil, so that the pressure oil acts on the top core 5 and the valve core 8 inside the valve sleeve respectively, and pushes the top core 5 and the valve core 8 to move to the right respectively; a plug 3 for limiting the top core is arranged at the countersunk hole at the left end of the valve sleeve, which is pressed in the valve sleeve by a spring. The left end of the valve sleeve 12 is always tangent to the feedback pin through the screw plug, spring seat and spring 2. To ensure that the valve sleeve and the feedback pin are always tangent, it is assumed that when the displacement is minimum (the feedback pin swings to the rightmost end), its compression spring can make the valve sleeve and the feedback pin tangent. Then, in the process of increasing displacement (the feedback pin moves to the left, the valve sleeve moves to the left, and the spring compression increases), the valve sleeve and the feedback pin can also be always tangent. Therefore, the spring stiffness setting value is that the rightward force (the product of compression and stiffness) generated by the spring at the minimum displacement is greater than the value obtained by the maximum solenoid valve pressure acting on the plug to generate the leftward force and the maximum pump pressure acting on the valve sleeve to generate the leftward force, so as to ensure that the middle left end face of the valve sleeve is always tangent to the feedback pin. The middle oil chamber 6 in the valve sleeve (the junction of the top core and the valve core) is provided with a channel connected to the valve sleeve oil drain channel to prevent the pump pressure oil of the right end oil chamber from leaking into the middle oil chamber, causing the middle oil chamber to be pressurized, causing structural function failure. The left end of the top core 5 is a spherical structure to prevent the top core 5 from adhering to the plug 3, and to control the oil from entering so that the top core cannot be pushed to move, causing the top core function to fail.

[0021] like Figure 1 As shown, the existing hydraulic pump power control structure, the maximum output power and power characteristic curve of the hydraulic pump have been set by the manufacturer on the hydraulic test bench before leaving the factory. Once the power value is set, its change is only affected by the system hydraulic pressure and the stiffness of the large and small springs.

[0022] like Figure 2As shown, it is a schematic diagram of an electro-hydraulic composite control power structure for a hydraulic pump provided by the utility model. The right end of the valve sleeve 12 is pressed against the large and small springs through the spring seat to close the opening of the valve core 8 and the valve sleeve 12. The other end is pressed against the spring 2 through the screw plug to make the middle left end face of the valve sleeve 12 always tangent to the feedback pin; the solenoid valve is energized, and the solenoid valve pressure oil enters the left end oil chamber 4, and the pressure generated acts on the ball head end of the top core 5 to make the top core 5 have a tendency to move to the right. When the right end of the top core 5 coincides with the left end of the valve core 8, the force on the left end of the valve core 8 and the pump pressure oil in the right end oil chamber 7 (such as Figure 4 As shown, at this time, the pressure is the pressure after the pump oil outlet passes through a fixed throttle port) and the resultant force (direction of the resultant force is to the right) acting on the valve core overcomes the resistance of the large and small springs and pushes the steel ball to the right, the valve core 8 and the valve sleeve 12 are opened, and the pressure oil in the right end oil chamber 7 leaks from the opening. The pump oil outlet pressure overcomes the flow control valve pressure (the control valve spring force and the right end oil chamber pressure) to push the flow valve core, the flow valve opening is opened, the pump oil outlet pressure acts on the servo plunger rodless chamber, pushes the servo plunger, the swash plate swing angle decreases, the pump displacement decreases (the pump displacement is the largest in the initial state), and the feedback pin moves to the right (such as Figure 2 ), the spring 2 pushes the valve sleeve 12 to the right and is always tangent to the feedback pin while closing the opening of the valve core 8 and the valve sleeve 12. At this time, the curve of the system pressure and the output flow of the hydraulic pump is inversely proportional, and the hydraulic pump enters constant power control. Compared with the original single hydraulic control, the newly added solenoid valve control pressure of this composite control structure reduces the pressure required by the right-end oil chamber 7, and the constant power shear starting point of the hydraulic pump moves forward, thereby achieving the purpose of reducing the constant power value. The left-end oil chamber 4 controls the pressure oil by a more sensitive electrical signal control, which can be customized according to the actual needs of customers, set different loading current values, and change the constant power shear starting point of the hydraulic pump to meet the comprehensive efficiency and energy consumption requirements of different users and multiple working conditions.

[0023] The above is only a preferred embodiment of the utility model, and is not any formal or substantial limitation of the utility model. It should be pointed out that ordinary technicians in this technical field can make some improvements and supplements without departing from the utility model, and these improvements and supplements should also be regarded as the protection scope of the utility model. Any technician familiar with this profession can make some changes, modifications and equivalent changes made by using the technical content disclosed above without departing from the spirit and scope of the utility model, which are all equivalent embodiments of the utility model; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the utility model are still within the scope of the technical solution of the utility model.

Claims

1. An electro-hydraulic composite power control structure for a hydraulic pump, characterized in that: It includes a valve body, a valve sleeve is arranged inside the valve body, the left and right ends of the valve sleeve are pressed in the valve body by springs, a slidable top core and valve core are arranged inside the valve sleeve, the top core and the valve core divide the oil chamber inside the valve sleeve into a left end oil chamber and a middle oil chamber, and a right end oil chamber is arranged on the inner wall of the right end of the valve sleeve; an electromagnetic valve for controlling power is fixed on the lower end surface of the valve body, an oil channel for introducing electromagnetic valve pressure oil and pump pressure oil is arranged inside the lower end of the valve body, which are respectively connected with the electromagnetic valve pressure oil channel and the oil leakage channel outlet arranged on the electromagnetic valve, and a plug for limiting the top core is arranged at the countersunk hole at the left end of the valve sleeve.

2. The electro-hydraulic composite power control structure for a hydraulic pump according to claim 1, characterized in that: The left end of the valve sleeve is always tangent to the feedback pin through the screw plug, the spring seat and the left end spring. When the spring stiffness is set to the minimum displacement, the rightward force generated by the spring is greater than the value obtained by the maximum solenoid valve pressure acting on the plug to generate a leftward force and the maximum pump pressure acting on the valve sleeve to generate a leftward force.

3. The electro-hydraulic composite power control structure for a hydraulic pump according to claim 1, characterized in that: The plug is pressed tightly into the valve sleeve by a left end spring, and the plug diameter is larger than the top core diameter.

4. The electro-hydraulic composite power control structure for a hydraulic pump according to claim 1, characterized in that: The middle oil chamber in the valve sleeve is provided with a passage communicating with the oil drain passage of the valve sleeve.

5. The electro-hydraulic composite power control structure for a hydraulic pump according to claim 1, characterized in that: The left end of the top core is a spherical structure.

6. The electro-hydraulic composite power control structure for a hydraulic pump according to claim 1, characterized in that: The solenoid valve is fixed to the lower end of the valve body by screws.

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