Servo valve upper cover structure capable of externally predicting fracture of bourdon tube

Abstract

The utility model belongs to the field of mechanical hydraulic pressure, and relates to a servo valve upper cover structure capable of externally predicting the fracture of a bourdon tube, which comprises a leakage pressure monitoring element and an upper cover shell, the upper cover shell is installed on a main valve body of the servo valve, the spring pipe is located in the upper cover shell, the leakage pressure monitoring element is arranged on the upper cover shell and used for monitoring the pressure of the upper cover shell, and when the spring pipe in the servo valve cracks and leaks oil liquid, the leakage pressure monitoring element can monitor the leakage pressure of the upper cover shell. The upper cover structure can effectively monitor internal pressure rise of the upper cover, marks are displayed on the outer side of the upper cover, and ground inspectors can observe the mechanical marks on the upper cover of the servo valve externally to predict fracture of an internal bourdon tube and replace the servo valve so as to avoid serious faults of abnormal work of the servo valve caused by continuous expansion of cracks of the bourdon tube.

Description

Technical Field

[0001] The utility model belongs to the field of mechanical hydraulics and relates to a servo valve upper cover structure capable of externally predicting the rupture of a spring tube. Background Art

[0002] The electro-hydraulic servo valve is an important control component of the electro-hydraulic servo system. It plays the role of electro-hydraulic conversion and power amplification in the system and is widely used in aviation, aerospace, ships and other fields.

[0003] The spring tube is a key component in servo valves, converting electrical signals into mechanical deflection. Fatigue and cracking of the spring tube, a resilient element, can cause product failure, uncontrolled output, and even malfunction.

[0004] The typical evolution of fatigue cracking in a spring tube begins with the appearance of initial microcracks on the tube surface, allowing oil inside the tube to seep into the upper cover. However, the servo valve maintains normal function and performance. The crack then gradually expands as the servo valve continues to operate, ultimately leading to a malfunction and being discovered. Therefore, it's crucial to be able to detect cracks on the outside of the servo valve before the initial microcracks significantly impact the valve's performance. Inspecting the servo valve's spring tube for cracks can effectively prevent serious aircraft failures caused by loss of servo valve performance. Utility Model Content

[0005] The technical problem solved by the utility model is as follows: The utility model proposes a servo valve upper cover structure that can externally predict the rupture of a spring tube. When cracks appear in the spring tube inside the servo valve and oil leaks out, the upper cover structure of the utility model can effectively monitor the pressure increase inside the upper cover and display a mark on the outside of the upper cover. Ground inspection personnel can predict the rupture of the internal spring tube by externally observing the mechanical mark on the servo valve upper cover and replace the servo valve to prevent the crack in the spring tube from continuing to expand and causing serious malfunction of the servo valve.

[0006] The technical solution of the utility model

[0007] A servo valve upper cover structure that can externally predict the rupture of a spring tube, the upper cover structure includes a leakage pressure monitoring element and an upper cover shell; the upper cover shell is installed on the servo valve main valve body, the spring tube is located inside the upper cover shell, and the leakage pressure monitoring element is arranged on the upper cover shell for monitoring the pressure of the upper cover shell.

[0008] Furthermore, the right end of the leakage pressure monitoring element is threaded and screwed into the threaded hole on the wall of the upper cover shell to form the upper cover structure.

[0009] Furthermore, the leakage pressure monitoring element includes an insert housing, a monitoring piston, a side spring, a lower spring, a wedge and a pressure-sensitive leather cup. The monitoring piston is slidably installed in the hole of the insert housing. The left side of the monitoring piston contacts the side spring, and the right side contacts the pressure-sensitive leather cup arranged inside the housing. The small rod at the left end of the monitoring piston can pass through the through hole on the left side of the insert housing. The surface of the small rod at the left end of the monitoring piston is provided with a red coating mark. When the monitoring piston compresses the side spring to the left and moves to the left limit position, the red coating mark on the surface of the small rod at the left end is exposed. When the monitoring piston is not in the left limit position, the red coating mark on the surface of the small rod at the left end is hidden in the insert housing.

[0010] Furthermore, the leakage pressure monitoring element further comprises a wedge block, which is installed in the insert housing groove, with the bottom of the wedge block in contact with the lower spring and the top of the wedge block cooperating with the monitoring piston.

[0011] Furthermore, the pressure-sensitive leather cup is installed in the right hole of the plug-in housing, and the left end of the pressure-sensitive leather cup is connected to the monitoring piston.

[0012] Furthermore, the wedge is made of magnetic conductive material, and the insert housing, monitoring piston and pressure-sensitive leather cup are all made of non-magnetic conductive materials.

[0013] Beneficial effects

[0014] This utility model proposes a servo valve cover structure that can externally predict spring tube rupture. The utility model can monitor the internal pressure increase of the servo valve cover and mark the pressure increase on the outside of the cover through a mechanical structure. Even after the internal pressure of the servo valve cover increases and then decreases, the utility model still displays the warning mark. By monitoring the internal pressure of the servo valve cover, the utility model predicts the state of spring tube rupture. In the event that the spring tube has microcracks but has little impact on the performance of the servo valve, the risk of rupture of the servo valve spring tube can be detected through routine ground inspections. This can effectively prevent the cracks from continuing to expand after the rupture of the spring tube and the resulting uncontrolled operation of the servo valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the servo valve installed in the utility model;

[0016] Figure 1 In the figure, 1 is the main valve body of the servo valve, 2 is the spring tube, 3 is the upper cover shell, and 4 is the leakage pressure monitoring element;

[0017] Figure 2 It is a structural diagram of the leakage pressure monitoring element;

[0018] Among them, 5 is the plug-in housing, 6 is the monitoring piston, 7 is the side spring, 8 is the lower spring, 9 is the wedge, and 10 is the pressure-sensitive leather cup;

[0019] P: Pressure inside the upper cover. DETAILED DESCRIPTION

[0020] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is in no way limited to any specific arrangement and method set forth below, but rather covers any improvements, replacements, and modifications of structures, methods, and devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, well-known structures and techniques are not shown to avoid unnecessary ambiguity in the present invention.

[0021] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] like Figure 1 、 Figure 2 As shown,

[0023] When assembling the upper cover structure of the present invention, the leakage pressure monitoring element 4 can be screwed into the threaded hole of the upper cover shell 3 to complete the assembly.

[0024] When assembling the leakage pressure monitoring element 4, the lower spring 8, wedge 9 and side spring 7 can be installed in the plug-in housing 5 in sequence. After the monitoring piston 6 and the pressure-sensing leather cup 10 are connected, they are inserted into the plug-in housing 5. After insertion, the shape of the pressure-sensing leather cup 10 is restored. After the monitoring piston 6 is inserted, the wedge 9 moves downward to the bottom of the groove and squeezes the lower spring 8.

[0025] In the initial state, the internal and external air pressures of the upper cover shell 3 are basically the same. Under the elastic force of the side spring 7, the monitoring piston 6 and the pressure-sensing leather cup 10 connected thereto are in the rightmost position, the wedge block 9 is at the bottom of the groove, the top surface contacts the outer ring surface of the monitoring piston 6, and the lower spring 8 is in a pre-compressed state.

[0026] When the internal spring tube 2 ruptures, the oil enters the upper cover from the spring tube 2, and the internal pressure P of the upper cover increases. The pressure-sensing leather cup 10 pushes the monitoring piston 6 to squeeze the side spring 7 to the left to the left limit position under the action of the internal and external pressure difference. The outer ring surface of the monitoring piston 6 no longer squeezes the top surface of the wedge 9. The wedge 9 moves upward under the elastic force of the lower spring 8, and jams the monitoring piston 6. In the absence of other external forces, the wedge 9 is in the upper position under the elastic force of the lower spring 8, which hinders the monitoring piston 6 from moving to the right, and the red coating on the surface of the small rod on the left side of the monitoring piston 6 is exposed.

[0027] As the aircraft oil source system stopped working, the pressure P inside the upper cover gradually dropped. Because the wedge block 9 always blocked the rightward movement of the monitoring piston 6, the red coating on the surface of the small rod on the left side of the monitoring piston 6 remained exposed for observation by ground inspection personnel, who determined that the servo valve spring tube was broken.

[0028] Except for wedge 9, which is made of magnetically conductive material, all other parts of the leakage pressure monitoring element 4 are made of non-magnetic materials. To restore the element to its working position, a strong magnet can be used to attract wedge 9 from the outside, forcing it to overcome the elastic force of lower spring 8 and move to the bottom of the groove. This simultaneously pushes the monitoring piston 6 to the right, returning the leakage pressure monitoring element 4 to its initial position.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present invention, and these modifications or replacements should all be included in the protection scope of the present invention.

Claims

1. A servo valve cover structure capable of externally predicting spring tube rupture, characterized in that: The upper cover structure includes a leakage pressure monitoring element and an upper cover shell; the upper cover shell is installed on the servo valve main valve body, the spring tube is inside the upper cover shell, and the leakage pressure monitoring element is arranged on the upper cover shell to monitor the pressure of the upper cover shell.

2. The servo valve cover structure capable of externally predicting spring tube rupture according to claim 1, characterized in that: The right end of the leakage pressure monitoring element is provided with a thread, which is screwed into the threaded hole on the wall of the upper cover shell to form the upper cover structure.

3. The servo valve cover structure capable of externally predicting spring tube rupture according to claim 1, characterized in that: The leakage pressure monitoring element includes a plug-in shell, a monitoring piston, a side spring, a lower spring, a wedge and a pressure-sensitive leather cup. The monitoring piston is slidably installed in the plug-in shell hole. The left side of the monitoring piston contacts the side spring, and the right side contacts the pressure-sensitive leather cup arranged inside the shell. The small rod at the left end of the monitoring piston can pass through the through hole on the left side of the plug-in shell. The surface of the small rod at the left end of the monitoring piston is provided with a red coating mark. When the monitoring piston compresses the side spring to the left and moves to the left limit position, the red coating mark on the surface of the small rod at the left end is exposed. When the monitoring piston is not in the left limit position, the red coating mark on the surface of the small rod at the left end is hidden in the plug-in shell.

4. The servo valve upper cover structure with external prediction of spring tube rupture according to claim 3 is characterized in that: The leakage pressure monitoring element further comprises a wedge block, which is installed in the insert housing groove, with the bottom of the wedge block in contact with the lower spring and the top of the wedge block cooperating with the monitoring piston.

5. The servo valve cover structure with external prediction of spring tube rupture according to claim 3, characterized in that: The pressure-sensitive leather cup is installed in the right hole of the plug-in housing, and the left end of the pressure-sensitive leather cup is connected to the monitoring piston.

6. The servo valve upper cover structure with external prediction of spring tube rupture according to claim 3, characterized in that: The wedge is made of magnetic material, while the plug-in housing, monitoring piston and pressure-sensitive leather cup are all made of non-magnetic materials.

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