A cold gas engine thrust measurement device

Abstract

The present invention discloses a thrust measurement device for a cold gas engine, which includes a fixed frame assembly and a moving frame assembly arranged on the fixed frame assembly. A thrust sensor is arranged on the fixed frame assembly, and a first connection position for connecting with the front end of the thrust chamber of the cold gas engine is arranged at the top of the thrust sensor; the moving frame assembly is slidably matched with the fixed frame assembly in the vertical direction, and a second connection position for connecting with the jet end of the thrust chamber is arranged on the moving frame assembly, and the second connection position is arranged directly opposite to the first connection position in the vertical direction. In the actual application process of this thrust measurement device for a cold gas engine, the interference of gravity and its own internal pressure on the measurement result is effectively avoided, the thrust measurement error is eliminated, and the accuracy of the measurement result is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine thrust testing, and particularly relates to a cold gas engine thrust measurement device. Background Art

[0002] Cold gas engines are mainly used for attitude adjustment of spacecraft such as rockets and satellites. By expanding and accelerating high-pressure inert gases, reaction thrust is generated according to Newton's third law. Cold gas propulsion engines directly convert pressure energy into kinetic energy without any chemical reactions.

[0003] The thrust of cold gas engines is generally below 300 N, belonging to the small thrust level, and their own weight is usually dozens of N. Since the thrust generation axes of current attitude hole engine test devices are all in the horizontal direction, the self-gravity of the engine has a certain interference on the measurement of horizontal thrust, resulting in a large thrust measurement error and inaccurate measurement results.

[0004] In summary, how to solve the problem that the thrust measurement error of the cold gas engine thrust measurement device is large and the measurement result is inaccurate has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a cold gas engine thrust measurement device to solve the problem that the thrust measurement error of the cold gas engine thrust measurement device is large and the measurement result is inaccurate.

[0006] To achieve the above purpose, the present invention provides a cold gas engine thrust measurement device, including a fixed frame assembly and a moving frame assembly arranged on the fixed frame assembly. A thrust sensor is arranged on the fixed frame assembly, and a first connection position for connecting with the front end of the thrust chamber of the cold gas engine is arranged at the top of the thrust sensor; the moving frame assembly is slidably matched with the fixed frame assembly in the vertical direction, and a second connection position for connecting with the jet end of the thrust chamber is arranged on the moving frame assembly, and the second connection position is arranged directly opposite to the first connection position in the vertical direction.

[0007] Preferably, the fixed frame assembly includes a lower fixed support plate and a slide rail arranged on the lower fixed support plate and arranged in the vertical direction. The thrust sensor is arranged on the lower fixed support plate; the moving frame assembly includes a sliding support plate and a slider arranged on the sliding support plate and slidably matched with the slide rail, and the second connection position is arranged on the sliding support plate.

[0008] Preferably, the slide rail is a positioning rod arranged on the lower fixed support plate, and the positioning rods are evenly arranged along the circumferential direction of the lower fixed support plate; the slider is a sliding sleeve sleeved on the positioning rod.

[0009] Preferably, the sliding support plate includes a central circular plate and a plurality of sub-support plates radially extending from the outer edge of the central circular plate. A through hole for the airflow at the jet end to pass through is provided in the middle of the central circular plate; the sub-support plates correspond to the positioning rods one by one, and the sliding sleeve is arranged at the end of the sub-support plate.

[0010] Preferably, a plurality of hollow holes are provided on the central circular plate, and the hollow holes are evenly arranged along the circumferential direction of the through hole.

[0011] Preferably, the sliding sleeve is a linear bearing.

[0012] Preferably, the fixed frame assembly further includes an upper fixed support plate arranged opposite to the lower fixed support plate, and the top end of the positioning rod is fixedly connected to the upper fixed support plate.

[0013] Preferably, the upper fixed support plate is of an annular structure.

[0014] Preferably, a blind hole for installing the thrust sensor is provided in the middle of the lower fixed support plate.

[0015] Preferably, counterbores are further provided on the lower fixed support plate and are evenly arranged along the circumferential direction of the blind hole. The counterbores are used to be fixed to the installation base through countersunk head bolts.

[0016] Compared with the content in the background art introduction, the above-mentioned cold gas engine thrust measurement device includes a fixed frame assembly and a moving frame assembly arranged on the fixed frame assembly. A thrust sensor is provided on the fixed frame assembly, and a first connection position for connecting to the front end of the thrust chamber of the cold gas engine is provided at the top of the thrust sensor; the moving frame assembly is slidably matched with the fixed frame assembly in the vertical direction, and a second connection position for connecting to the jet end of the thrust chamber is provided on the moving frame assembly, and the second connection position and the first connection position are arranged opposite to each other in the vertical direction. In the actual application process of this cold gas engine thrust measurement device, first, the front end of the thrust chamber of the cold gas engine is fixed to the first connection position at the top of the thrust sensor, and the jet end of the thrust chamber is fixed to the second connection position on the moving frame assembly. Then, the jet end of the thrust chamber is blocked and the thrust chamber is supplied with gas. After the supply pressure is adjusted to the rated working pressure, the system tightness is checked. Since the first connection position and the second connection position are arranged opposite to each other in the vertical direction, at this time, by zeroing the measurement reference of the thrust sensor, the deviation caused by the action of gravity and internal pressure can be eliminated. After that, the gas is discharged and the blockage of the jet end is removed. Finally, according to the preset pressure, high-pressure gas is supplied to the thrust chamber through the gas supply system. The high-pressure gas expands in the thrust chamber and is discharged upward at high speed, generating a downward thrust. The thrust sensor outputs the measurement signal to the acquisition device. This cold gas engine thrust measurement device effectively avoids the interference of gravity and its own internal pressure on the measurement result, eliminates the thrust measurement error, and greatly improves the accuracy of the measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the overall structure of the cold gas engine thrust measurement device provided by the embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of the upper fixed support plate provided by the embodiment of the present invention;

[0020] Figure 3 For Figure 2 the A-A cross-sectional structure diagram of

[0021] Figure 4 It is a schematic diagram of the structure of the lower fixed support plate provided by the embodiment of the present invention;

[0022] Figure 5 For Figure 4 the B-B cross-sectional structure diagram of

[0023] Figure 6 It is a schematic diagram of the structure of the moving frame assembly provided by the embodiment of the present invention;

[0024] Figure 7 For Figure 6 the C-C cross-sectional structure diagram of

[0025] Upper Figures 1-7 In

[0026] Fixed frame assembly 1, lower fixed support plate 11, blind hole 11a, counterbore 11b, slide rail 12, upper fixed support plate 13, moving frame assembly 2, sliding support plate 21, central circular plate 21a, sub-support plate 21b, hollow hole 21c, through hole 21d, slider 22, thrust sensor 3, thrust chamber 4. Specific embodiments

[0027] The core of the present invention is to provide a cold gas engine thrust measurement device to solve the problem that the thrust measurement error of the cold gas engine thrust measurement device is relatively large, resulting in inaccurate measurement results.

[0028] To enable those skilled in the art to better understand the technical solutions provided by the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left" and "right" and the like are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated positions or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0030] As Figures 1-7 shown, a thrust measurement device for a cold gas engine provided by an embodiment of the present invention includes a fixed frame assembly 1 and a moving frame assembly 2 disposed on the fixed frame assembly 1. A thrust sensor 3 is disposed on the fixed frame assembly 1, and a first connection position for connecting with the front end of the thrust chamber 4 of the cold gas engine is disposed at the top of the thrust sensor 3; the moving frame assembly 2 is slidably engaged with the fixed frame assembly 1 in the vertical direction, and a second connection position for connecting with the jet end of the thrust chamber 4 is disposed on the moving frame assembly 2, and the second connection position and the first connection position are disposed opposite to each other in the vertical direction.

[0031] In the actual application process of this thrust measurement device for a cold gas engine, first, the front end of the thrust chamber of the cold gas engine is fixed to the first connection position at the top of the thrust sensor, and the jet end of the thrust chamber is fixed to the second connection position on the moving frame assembly. Then, the jet end of the thrust chamber is blocked and the thrust chamber is supplied with gas. After the supply pressure is adjusted to the rated working pressure, the system tightness is checked. Since the first connection position and the second connection position are opposite to each other in the vertical direction, at this time, by zeroing the measurement reference of the thrust sensor, the deviation generated by the action of gravity and internal pressure can be eliminated. After that, the gas is discharged and the blockage of the jet end is removed. Finally, according to the preset pressure, high-pressure gas is supplied to the thrust chamber through the gas supply system. The high-pressure gas expands in the thrust chamber and is discharged upward at high speed, generating a downward thrust. The thrust sensor outputs the measurement signal to the acquisition device. This thrust measurement device for a cold gas engine effectively avoids the interference of gravity and its own internal pressure on the measurement result, eliminates the thrust measurement error, and greatly improves the accuracy of the measurement result.

[0032] In some specific implementation schemes, the specific structure of the fixed frame assembly 1 may include a lower fixed support plate 11 and a slide rail 12 disposed on the lower fixed support plate 11 and arranged in the vertical direction, and the thrust sensor 3 is disposed on the lower fixed support plate 11; the movable frame assembly 2 includes a sliding support plate 21 and a slider 22 disposed on the sliding support plate 21 and slidingly matched with the slide rail 12, and the second connection position is disposed on the sliding support plate 21. The sliding match between the fixed frame assembly and the movable frame assembly is achieved through the slider and the slide rail. Of course, it can be understood that the above-mentioned method of providing a slide rail on the fixed frame assembly and providing a slider on the movable frame assembly is only a preferred example of the embodiment of the present invention. In actual application, it can also be a method of providing a slider on the fixed frame assembly and providing a slide rail on the movable frame assembly, except that the slider is fixed and the slide rail moves.

[0033] In some more specific implementation schemes, the specific structural form of the above-mentioned slide rail 12 can be a positioning rod arranged on the lower fixed support plate 11, and the positioning rods are evenly arranged along the circumference of the lower fixed support plate 11; the slider 22 can specifically be a sliding sleeve mounted on the positioning rod. The sliding fit is achieved by the circumferentially arranged positioning rods cooperating with the sliding sleeve, so that the sliding of the movable frame assembly relative to the fixed frame assembly is more stable and lateral movement is avoided. Of course, it can be understood that the sliding mode of the above-mentioned positioning rod and the sliding sleeve is only a preferred example of the structure of sliding fit in the embodiment of the present invention. In actual application, other interactive matching structural forms commonly used by technicians in this field can also be adopted. For example, a vertically arranged slide groove is provided on the lower fixed support plate, and the number of the slide grooves is multiple, and the opening of the slide groove faces the center of the lower fixed support plate, and a slider corresponding to the slide groove and sliding fit is provided on the movable frame assembly. In actual application, it can be selected according to actual needs, and no more specific restrictions are made here.

[0034] In a further embodiment, in order to reduce the overall weight of the moving frame assembly as much as possible, the specific structure of the sliding support plate 21 may include a central circular plate 21a and a plurality of sub-support plates 21b radially extending from the outer edge of the central circular plate 21a, wherein a through hole 21d for the airflow at the jet end to pass through is provided in the middle of the central circular plate 21a; the sub-support plates 21b correspond to the positioning rods one by one, and the sliding sleeve is provided at the end of the sub-support plate 21b. By designing the moving frame assembly into the above-mentioned structural form, the weight is lighter than that of a structure of a whole plate.

[0035] In a further embodiment, in order to further reduce the overall weight of the moving frame assembly, a plurality of hollow holes 21c may be provided on the central circular plate 21a, and the hollow holes 21c are evenly arranged along the circumference of the through hole 21d. The hollow holes can reduce the overall weight on the one hand, and on the other hand, the hollow holes are evenly arranged around the circumference to ensure that the central circular plate is subjected to more balanced forces at various positions around the circumference when subjected to forces.

[0036] In some specific embodiments, in order to make the measurement results more accurate and avoid the influence of sliding friction on the measurement results, the sliding sleeve can generally be designed into the structure of a linear bearing. Through the arrangement of the linear bearing, the friction coefficient can be effectively reduced, the frictional resistance can be lowered, and then the accuracy of the thrust measurement results can be improved.

[0037] In a further embodiment, in order to ensure the overall stability of the fixed frame assembly and the stability of the positioning rod, the above-mentioned fixed frame assembly 1 may further include an upper fixed support plate 13 arranged opposite to the lower fixed support plate 11, and the top end of the positioning rod is fixedly connected to the upper fixed support plate 13. By fixing the positioning rod with the upper and lower fixed support plates at the same time, the stability of the position of the positioning rod can be effectively improved, and the problem that the positioning rod shakes and affects the measurement results is avoided.

[0038] In a further embodiment, in order to more effectively reduce the overall weight of the thrust measuring device, the above-mentioned upper fixed support plate 13 is generally preferably in a circular ring structure. Of course, it can be understood that the above-mentioned form of adopting the circular ring structure is only a preferred example of the structure of the upper fixed support plate in the embodiments of the present invention. In the actual application process, other structural forms commonly used by those skilled in the art can also be adopted, such as the structure of a hollowed-out plate, etc.

[0039] In some specific embodiments, in order to facilitate the installation of the thrust sensor, a blind hole 11a for installing the thrust sensor 3 can be provided in the middle of the above-mentioned lower fixed support plate 11. The thrust sensor can be embedded in the blind hole. It should be noted here that the size of the blind hole is generally slightly larger than the circumferential size of the thrust sensor, so that the thrust sensor can just be put in.

[0040] In a further embodiment, in order to facilitate the fixation of the fixed frame assembly, counterbores 11b are also provided on the above-mentioned lower fixed support plate 11 and are uniformly arranged along the circumference of the blind hole 11a. The counterbores 11b are used to be fixed to the installation base through countersunk head bolts. By connecting to the installation base in the way of setting counterbores, the top of the lower fixed support plate can be prevented from exposing bolts, and the flatness of the surface of the lower fixed support plate is ensured.

[0041] For those skilled in the art to better understand the technical solution of the present invention, the following specifically describes the installation process of the relatively preferred solution:

[0042] The fixed frame assembly 1 includes a lower fixed support plate 11, an upper fixed support plate 13, and positioning rods. Its main function is to install and support other parts and transfer the thrust to the installation base. The lower fixed support plate 11 is processed with 4 - 8 countersunk through holes and fixed to the base by 4 - 8 screws with a specification of M8×20. The base can be a working platform or a simple bracket, and the installation plane should be kept as horizontal as possible. The lower fixed support plate 11 is processed with M8 threaded blind holes. First, screw a headless screw with a specification of M8×12 into the threaded blind hole and tighten it manually until it is tight. The positioning rod has a diameter of 16 mm and a length of about 300 mm, and both ends are processed with M8 threaded holes. Connect any one end of the 3 positioning rods to the headless screw and tighten it manually. The upper fixed support plate 13 is of an annular structure, with three stepped through holes evenly distributed along the circumference. The characteristics of the stepped through holes are that the holes at both ends are large, the middle hole is small, the diameter of the middle hole is 9 mm, the diameter of the lower large hole is 16 mm, and the diameter of the upper large hole is 14 mm. Place the upper fixed support plate 13 on the upper part of the positioning rods and insert the 3 positioning rods into the 3 holes with a diameter of 16 mm respectively, and fasten them with socket head cap screws with a specification of GB / T70 M8×12. The tightening torque is 15 - 20 N.m.

[0043] The moving frame assembly includes a sliding support plate 21 and linear bearings 23. The sliding support plate 21 and the linear bearings 23 are connected by socket head cap screws with a specification of GB / T70 M4×10. The 3 positioning rods pass through the 3 linear bearings 23 respectively, and the sliding support plate 21 can move up and down freely along the positioning rods.

[0044] The working process of measurement is as follows:

[0045] Before the test, connect the cold gas engine and the thrust sensor 3 with 4 socket head cap screws with a specification of GB / T70 M8×12, then connect them to the sliding support plate 21 with socket head cap screws with a specification of GB / T70 M8×12, and make the bottom of the sensor contact with the lower fixed support plate 11.

[0046] Connect the gas supply hose to the inlet of the thrust chamber of the cold gas engine, install an airtight plug from the central hole of the sliding support plate 21, adjust the gas supply pressure to the rated working pressure, check the system tightness, and zero the measurement reference of the thrust sensor. At this time, the deviation caused by the action of gravity and internal pressure can be eliminated. Then discharge the gas and remove the airtight plug.

[0047] According to the preset pressure, the gas supply system supplies high - pressure gas to the thrust chamber. The high - pressure gas expands in the thrust chamber and is discharged upward at high speed, generating a downward thrust. The thrust sensor outputs the measurement signal to the acquisition device.

[0048] It should be noted that the above-mentioned fixing method and the specifications and quantities of the fasteners used are only preferred examples given by the present invention for the relatively common types of thrust chambers. In actual application, they can be configured according to actual needs. Additionally, it should be noted that the above-mentioned thrust measurement device can adapt to cold gas propulsion engines with any thrust range by changing the installation interface between the moving frame and the thrust chamber and replacing the thrust sensor with a matching range. In this embodiment, it is mainly applicable to cold gas propulsion engines with a thrust of 5 - 500 N.

[0049] The above has introduced in detail the cold gas engine thrust measurement device provided by the present invention. It should be noted that each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0050] It also needs to be noted that in this article, terms such as "including", "comprising" or any other variant thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such an article or device. Without further limitations, an element defined by the statement "including one..." does not exclude the existence of another identical element in the article or device including the above-mentioned element.

[0051] Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A thrust measurement device for a cold gas engine, characterized in that, it includes a fixed frame assembly (1) and a moving frame assembly (2) arranged on the fixed frame assembly (1). A thrust sensor (3) is arranged on the fixed frame assembly (1). At the top of the thrust sensor (3), there is a first connection position for connecting with the front end of the thrust chamber (4) of the cold gas engine; the moving frame assembly (2) is slidably matched with the fixed frame assembly (1) in the vertical direction. On the moving frame assembly (2), there is a second connection position for connecting with the jet end of the thrust chamber (4), and the second connection position is arranged directly opposite to the first connection position in the vertical direction; During the actual application process of the cold gas engine thrust measurement device, first, fix the front end of the thrust chamber to the first connection position and fix the jet end to the second connection position. Then, block the jet end and supply gas to the thrust chamber. After adjusting the supply gas pressure to the rated working pressure, check the system tightness, zero the measurement reference of the thrust sensor. After that, discharge the gas and remove the block of the jet end. Finally, supply high-pressure gas to the thrust chamber through the gas supply system according to a preset pressure. The high-pressure gas expands in the thrust chamber and is discharged upward, generating a downward thrust, and the thrust sensor outputs the measurement signal to the acquisition device.

2. The cold gas engine thrust measurement device according to claim 1, characterized in that, the fixed frame assembly (1) includes a lower fixed support plate (11) and a slide rail (12) arranged on the lower fixed support plate (11) and arranged in the vertical direction. The thrust sensor (3) is arranged on the lower fixed support plate (11); the moving frame assembly (2) includes a sliding support plate (21) and a slider (22) arranged on the sliding support plate (21) and slidably matched with the slide rail (12). The second connection position is arranged on the sliding support plate (21).

3. The cold gas engine thrust measurement device according to claim 2, characterized in that, the slide rail (12) is a positioning rod arranged on the lower fixed support plate (11), and the positioning rods are evenly arranged along the circumferential direction of the lower fixed support plate (11); the slider (22) is a sliding sleeve sleeved on the positioning rod.

4. The cold gas engine thrust measurement device according to claim 3, characterized in that, the sliding support plate (21) includes a central circular plate (21a) and a plurality of sub-support plates (21b) radially extending from the outer edge of the central circular plate (21a). In the middle of the central circular plate (21a), there is a through hole (21d) for the airflow of the jet end to pass through; the sub-support plates (21b) correspond to the positioning rods one by one, and the sliding sleeve is arranged at the end of the sub-support plate (21b).

5. The cold gas engine thrust measurement device according to claim 4, characterized in that, a plurality of hollow holes (21c) are arranged on the central circular plate (21a), and the hollow holes (21c) are evenly arranged along the circumferential direction of the through hole (21d).

6. The cold gas engine thrust measurement device according to claim 3, characterized in that, the sliding sleeve is a linear bearing.

7. The cold gas engine thrust measurement device according to claim 3, characterized in that, the fixed frame assembly (1) further includes an upper fixed support plate (13) arranged opposite to the lower fixed support plate (11), and the top end of the positioning rod is fixedly connected to the upper fixed support plate (13).

8. The cold gas engine thrust measurement device according to claim 7, characterized in that, the upper fixed support plate (13) is of an annular structure.

9. The cold gas engine thrust measurement device according to any one of claims 1-8, characterized in that, a blind hole (11a) for installing the thrust sensor (3) is provided in the middle of the lower fixed support plate (11).

10. The cold gas engine thrust measurement device according to claim 9, characterized in that, counterbores (11b) are further provided on the lower fixed support plate (11) and are uniformly arranged along the circumference of the blind hole (11a), and the counterbores (11b) are used to be fixed to the installation base by countersunk head bolts.

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