High-frequency hydraulic pulsation signal generating device and method based on volume cavity change

Abstract

The invention discloses a high-frequency hydraulic pulsation signal generating device and method based on volume cavity change, and relates to the technical field of aero-engine tests. According to the test system, pipeline pressure pulsation simulation is achieved in a hydraulic pulsation injection mode, the change of a single-acting cylinder containing cavity is controlled by adjusting the speed of a servo valve to achieve the change of output pressure, and high-frequency closed-loop control is conducted by feeding back a speed signal through a speed sensor at the single-acting cylinder. And meanwhile, in order to avoid cylinder collision of the hydraulic cylinder, a low-frequency position signal is input, and position closed loop is carried out by utilizing a feedback displacement signal of a displacement sensor at a single-acting cylinder. The test system has the advantage that controllable high-frequency hydraulic pulsation can be generated, and a high-frequency response characteristic test can be completed by injecting signals at an inlet of a fuel pump performance test bench.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine testing, and in particular relates to a device and method for generating a high-frequency hydraulic pulsation signal based on volume cavity changes. Background Art

[0002] In the process of conducting frequency characteristic research on mechanical hydraulic products of aircraft engines, it is necessary to study the frequency response characteristics of hydraulic sensing components (such as pressure sensors) or pressure control components (such as differential pressure valves). Dynamic test is an important part of the research process. Therefore, it is necessary to build a hydraulic pulsation signal generation system with a large frequency range and controllable to provide dynamic input signals for the test object. By measuring and analyzing the response data of the test object, its frequency response characteristics can be obtained. Among them, the hydraulic pulsation signal generation system is a key system, and there is currently no relevant technical solution in the industry. Summary of the invention

[0003] Based on the above background, it is proposed to provide a high-frequency hydraulic pulsation signal generating system and an implementation method thereof, which are used for frequency response characteristic testing of hydraulic components.

[0004] In view of this, according to one aspect of an embodiment of the present invention, a high-frequency hydraulic pulsation signal generating device based on volume cavity change is provided, comprising: a main system, a control system and a hydraulic pulsation generating system, wherein hydraulic pulsation regulation is achieved by dynamically adjusting the volume cavity of the main hydraulic system, wherein the main system further comprises a high-frequency response pressure transmitter 1, an oil tank 3 and a high-level oil tank 4, and the high-frequency response pressure transmitter 1 is used to measure the actual hydraulic pulsation value; the control system further comprises a speed sensor 5 and a displacement sensor 6, the speed sensor 5 is used to measure the extension and retraction speed of the hydraulic cylinder piston rod, and the displacement sensor 6 is used to monitor the position of the hydraulic cylinder piston rod; the hydraulic pulsation generating system further comprises a double-acting hydraulic cylinder 7, a single-acting hydraulic cylinder 8 and a high-frequency response electro-hydraulic servo valve 9, the cylinder rod of the double-acting hydraulic cylinder 7 is rigidly connected to the cylinder rod of the single-acting hydraulic cylinder 8, the rod cavity of the single-acting hydraulic cylinder 8 is connected to the high-level oil tank 4 of the main system, and the rodless cavity is connected to the main system; the high-frequency response electro-hydraulic servo valve 9 is used to control the movement direction and speed of the double-acting hydraulic cylinder 7.

[0005] Optionally, it also includes a constant current source and a constant pressure source, the constant current source provides a constant flow of hydraulic oil to the main system, and the constant pressure source provides a constant pressure of hydraulic oil to the hydraulic pulsation generating system, wherein the constant current source and the constant pressure source are both independent hydraulic sources.

[0006] Optionally, a hydraulic booster cylinder-acting element is used to replace the double-acting hydraulic cylinder 7 , the single-acting hydraulic cylinder 8 and the main system high-level oil tank 4 .

[0007] Optionally, the main system further comprises a fixed throttle hole 2, which is directly connected to the main system oil tank 3, and is used for separately setting the fixed throttle hole 2 when the main system lacks an oil unloading pipeline.

[0008] According to another aspect of an embodiment of the present invention, there is also provided a method for generating a high-frequency hydraulic pulsation signal based on volume chamber changes, using any of the above-mentioned devices, including: during the hydraulic pulsation test, the speed sensor 5 collects the speed signal of the hydraulic cylinder 7, discretizes the speed control curve and compares it with the speed signal, and converts it into a control signal of a high-frequency response electro-hydraulic servo valve 9 through the controller 2, so as to realize real-time control of the volume change speed, thereby realizing the pressure pulsation of the hydraulic pulsation generating system to be injected in a sinusoidal form, and finally realizing the injection of periodic pressure pulsation by the volume change of the rodless chamber of the single-acting hydraulic cylinder 8.

[0009] Optionally, in order to prevent the hydraulic cylinder piston rod from hitting the cylinder due to the zero deviation generated by the speed closed loop, the hydraulic cylinder piston rod needs to be kept moving near the middle position, and the controller 1 uses the position feedback signal of the displacement sensor 6 to form a position closed loop.

[0010] Optionally, the position closed-loop signal is a low-frequency signal.

[0011] Optionally, if the tested part is a blind hole, a fixed throttle hole 2 needs to be set for unloading oil from the main system. The beneficial effect of the present invention is that a potential gradient distribution type high temperature anti-corrosion coating and a preparation method thereof are proposed, which greatly improves the protection efficiency of the cathodic protection coating through the superposition and adaptation of different potential layers, achieves a longer service life of the coating while effectively reducing the thickness, and prolongs the maintenance and repair cycle.

[0012] The designed pressure regulating device can realize the control of the amplitude and signal frequency of high-frequency hydraulic pulsation, and provide a test method for the research needs of the frequency response characteristics of products such as hydraulic sensing components (such as pressure sensors) or pressure control components (such as differential pressure valves). This test system realizes the simulation of pipeline pressure pulsation by injecting hydraulic pulsation, controls the change of the single-acting cylinder volume by adjusting the speed of the servo valve to achieve the change of output pressure, and performs high-frequency closed-loop control by feedback of the speed signal by the speed sensor at the single-acting cylinder, so that the pressure fluctuation injected into the test piece is in the form of a sine wave. At the same time, in order to avoid the hydraulic cylinder from hitting the cylinder, the low-frequency position signal is input and the feedback displacement signal of the displacement sensor at the single-acting cylinder is used for position closed-loop. This test system has the advantage of generating controllable high-frequency hydraulic pulsation, and can complete the high-frequency frequency response characteristic test with the injection signal at the inlet of the fuel pump performance test bench. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The hydraulic principle diagram of the hydraulic pulsation signal generating system according to the present invention.

[0014] Figure 2 Graph showing a speed control signal of a hydraulic pulsation signal generating system according to the present invention.

[0015] Figure 3FIG. 4 is a block diagram of speed closed-loop control according to the present invention.

[0016] Description of reference numerals:

[0017] 1- high-frequency response pressure transmitter, 2- fixed throttle hole, 3- main system oil tank, 4- main system high-level oil tank, 5- speed sensor, 6- displacement sensor, 7- double-acting hydraulic cylinder, 8- single-acting hydraulic cylinder, 9- high-frequency response electro-hydraulic servo valve, 10- control oil tank. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] According to one aspect of an embodiment of the present invention, a high-frequency hydraulic pulsation signal generating device based on volume cavity change is provided, comprising: a main system, a control system and a hydraulic pulsation generating system, wherein hydraulic pulsation regulation is achieved by dynamically adjusting the volume cavity of the main hydraulic system, wherein the main system further comprises a high-frequency response pressure transmitter 1, an oil tank 3 and a high-level oil tank 4, wherein the high-frequency response pressure transmitter 1 is used to measure the actual hydraulic pulsation value; the control system further comprises a speed sensor 5 and a displacement sensor 6, wherein the speed sensor 5 is used to measure the extension and retraction speed of the hydraulic cylinder piston rod, and the displacement sensor 6 is used to monitor the position of the hydraulic cylinder piston rod; the hydraulic pulsation generating system further comprises a double-acting hydraulic cylinder 7, a single-acting hydraulic cylinder 8 and a high-frequency response electro-hydraulic servo valve 9, wherein the cylinder rod of the double-acting hydraulic cylinder 7 is rigidly connected to the cylinder rod of the single-acting hydraulic cylinder 8, the rod cavity of the single-acting hydraulic cylinder 8 is connected to the high-level oil tank 4 of the main system, and the rodless cavity is connected to the main system; the high-frequency response electro-hydraulic servo valve 9 is used to control the movement direction and speed of the double-acting hydraulic cylinder 7.

[0020] Furthermore, it also includes a constant current source and a constant pressure source. The constant current source provides a constant flow of hydraulic oil to the main system, and the constant pressure source provides a constant pressure of hydraulic oil to the hydraulic pulsation generating system, wherein the constant current source and the constant pressure source are both independent hydraulic sources.

[0021] Furthermore, a hydraulic booster cylinder is used to act as a component to replace the double-acting hydraulic cylinder 7 , the single-acting hydraulic cylinder 8 and the main system high-level oil tank 4 .

[0022] Furthermore, the main system also includes a fixed throttle hole 2, which is directly connected to the main system oil tank 3, and is used when the main system lacks an oil unloading pipeline and the fixed throttle hole 2 needs to be separately set.

[0023] According to another aspect of an embodiment of the present invention, there is also provided a method for generating a high-frequency hydraulic pulsation signal based on volume chamber changes, using any of the above-mentioned devices, including: during the hydraulic pulsation test, the speed sensor 5 collects the speed signal of the hydraulic cylinder 7, discretizes the speed control curve and compares it with the speed signal, and converts it into a control signal of a high-frequency response electro-hydraulic servo valve 9 through the controller 2, so as to realize real-time control of the volume change speed, thereby realizing the pressure pulsation of the hydraulic pulsation generating system to be injected in a sinusoidal form, and finally realizing the injection of periodic pressure pulsation by the volume change of the rodless chamber of the single-acting hydraulic cylinder 8.

[0024] Furthermore, in order to prevent the zero deviation generated by the speed closed loop from causing the hydraulic cylinder piston rod to hit the cylinder, the hydraulic cylinder piston rod needs to be kept moving near the middle position, and the controller 1 uses the position feedback signal of the displacement sensor 6 to form a position closed loop.

[0025] Furthermore, the position closed-loop signal is a low-frequency signal.

[0026] Furthermore, if the tested part is a blind hole, a fixed throttle hole 2 needs to be set for unloading oil from the main system. The beneficial effect of the present invention is that a potential gradient distribution type high temperature anti-corrosion coating and a preparation method thereof are proposed, which greatly improves the protection efficiency of the cathodic protection coating through the superposition and adaptation of different potential layers, achieves a higher service life of the coating while effectively reducing the thickness, and prolongs the maintenance and repair cycle.

[0027] Example

[0028] Hydraulic principle from hydraulic pulsation signal generation system Figure 1 It can be seen that this system is divided into three subsystems: the main system, the control system, and the hydraulic pulsation generation system. The hydraulic pulsation regulation is achieved by dynamically adjusting the main hydraulic system volume. The high-frequency response pressure transmitter 1 is used to measure the actual hydraulic pulsation value; the fixed throttle hole 2 is set on demand. When the main system lacks an oil unloading pipeline, a fixed throttle hole needs to be set separately and directly connected to the main system oil tank 3; the speed sensor 5 measures the extension and retraction speed of the hydraulic cylinder piston rod in real time; the displacement sensor 6 monitors the position of the hydraulic cylinder piston rod in real time; the cylinder rod of the double-acting hydraulic cylinder 7 is rigidly connected to the cylinder rod of the single-acting hydraulic cylinder 8; the rod cavity of the single-acting hydraulic cylinder 8 is connected to the main system high-level oil tank 4, and the rodless cavity is connected to the main system; the high-frequency response electro-hydraulic servo valve 9 controls the movement direction and speed of the double-acting hydraulic cylinder 7. Figure 1 In the embodiment, the constant current source provides a constant flow of hydraulic oil for the main system, and the constant pressure source provides a constant pressure of hydraulic oil for the hydraulic pulsation generating system, wherein the constant current source and the constant pressure source are both independent hydraulic sources. In addition, a component similar to a hydraulic booster cylinder can also be used to replace the double-acting hydraulic cylinder 7, the single-acting hydraulic cylinder 8 and the main system high-level oil tank 4.

[0029] The calculation process of the speed control signal of the hydraulic cylinder is as follows:

[0030] The instantaneous velocity of the single-acting hydraulic cylinder 8 is represented by v, the instantaneous velocity is a vector, and the area of ​​the rodless chamber piston is represented by S. Then the instantaneous flow change caused by the instantaneous change of the main hydraulic system volume chamber can be expressed as:

[0031] ΔQ=S·v (1)

[0032] Wherein, v is a vector, and ΔQ is set to be a positive value when the rodless chamber volume of the single-acting hydraulic cylinder 8 decreases, and ΔQ is set to be a negative value when the rod chamber volume increases.

[0033] According to the differential pressure flow formula:

[0034]

[0035] Wherein, Q represents the flow rate; A represents the sum of the oil unloading port areas of the main system;

[0036]

[0037] Among them, P 0 is the steady-state pressure of the main system; ΔP is the pressure pulsation value.

[0038] According to formula (1) and formula (3), we can get:

[0039]

[0040] In actual operation, the pressure pulsation is usually set as a sine wave, that is,

[0041] ΔP=Bsin(f·t) (5)

[0042] Where B is the pulsation amplitude, f is the pulsation frequency, and according to formula (4) and formula (5), the setting curve of the hydraulic cylinder's motion speed v can be obtained as follows: Figure 2 shown.

[0043] During the hydraulic pulsation test, first, the main system provides a stable constant current source. At this time, if the tested part is a blind hole, a fixed throttle hole 2 needs to be set to help the main system unload oil. If the tested part is a throttle hole, the throttle hole 2 may not be set; then a constant pressure source is provided for the hydraulic pulsation generating system, and the speed sensor 5 collects the speed signal of the hydraulic cylinder 7, discretizes the speed control curve and compares it with it, and converts it into a control signal of the high-frequency response electro-hydraulic servo valve 9 through the controller 2, so as to realize the real-time control of the volume change speed, and then realize the pressure pulsation of the hydraulic pulsation generating system in the form of a sine wave; in addition, in order to avoid the zero deviation generated by the speed closed loop causing the hydraulic cylinder piston rod to hit the cylinder, the hydraulic cylinder piston rod needs to be kept moving near the middle position, and the controller 1 is used to form a position closed loop with the position feedback signal of the displacement sensor 6, wherein the position closed loop signal is a low-frequency signal, which does not interfere with the high-frequency speed signal. The control principle block diagram is as follows Figure 3As shown, finally, the injection of periodic pressure pulsation is achieved by the change of the rodless chamber volume of the single-acting hydraulic cylinder 8.

[0044] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A high-frequency hydraulic pulsation signal generating device based on volume chamber change, characterized in that: include: The main system, the control system and the hydraulic pulsation generating system realize hydraulic pulsation regulation by dynamically adjusting the main hydraulic system volume chamber, wherein the main system also includes a high-frequency response pressure transmitter (1), an oil tank (3) and a high-level oil tank (4), wherein the high-frequency response pressure transmitter (1) is used to measure the actual hydraulic pulsation value; the control system also includes a speed sensor (5) and a displacement sensor (6), wherein the speed sensor (5) is used to measure the extension and retraction speed of the hydraulic cylinder piston rod, and the displacement sensor (6) is used to monitor the position of the hydraulic cylinder piston rod; the hydraulic pulsation generating system also includes a double-acting hydraulic cylinder (7), a single-acting hydraulic cylinder (8) and a high-frequency response electro-hydraulic servo valve (9), wherein the cylinder rod of the double-acting hydraulic cylinder (7) is rigidly connected to the cylinder rod of the single-acting hydraulic cylinder (8), the rod chamber of the single-acting hydraulic cylinder (8) is connected to the high-level oil tank (4) of the main system, and the rodless chamber is connected to the main system; the high-frequency response electro-hydraulic servo valve (9) is used to control the movement direction and speed of the double-acting hydraulic cylinder (7).

2. The device according to claim 1, characterized in that It also includes a constant current source and a constant pressure source. The constant current source provides a constant flow of hydraulic oil to the main system, and the constant pressure source provides a constant pressure of hydraulic oil to the hydraulic pulsation generating system. Both the constant current source and the constant pressure source are independent hydraulic sources.

3. The device according to claim 1, characterized in that The components acting as a hydraulic booster cylinder are used to replace the double-acting hydraulic cylinder (7), the single-acting hydraulic cylinder (8) and the main system high-level oil tank (4).

4. The device according to claim 1, characterized in that The main system also includes a fixed throttle hole (2) which is directly connected to the main system oil tank (3) and is used to separately set the fixed throttle hole (2) when the main system lacks an oil unloading pipeline.

5. A method for generating a high-frequency hydraulic pulsation signal based on volume chamber changes, characterized in that: The device as described in any one of claims 1 to 4 is used, comprising: during the hydraulic pulsation test, the speed sensor (5) collects the speed signal of the hydraulic cylinder (7), discretizes the speed control curve and compares it with the speed signal, and converts it into a control signal of a high-frequency response electro-hydraulic servo valve (9) through a controller (2), thereby realizing real-time control of the volume change speed, thereby realizing the injection of the pressure pulsation of the hydraulic pulsation generating system in a sinusoidal form, and finally realizing the injection of periodic pressure pulsation by the volume change of the rodless chamber of the single-acting hydraulic cylinder (8).

6. The method according to claim 5, characterized in that The piston rod of the hydraulic cylinder is kept moving near the middle position, and a position closed loop is formed by using the controller (1) and the position feedback signal of the displacement sensor (6).

7. The method according to claim 6, characterized in that The position closed-loop signal is a low-frequency signal.

8. The method according to claim 5, characterized in that At this time, if the tested part is a blind hole, a fixed throttle hole (2) needs to be set for unloading oil from the main system.

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