Large-scale single-vibration-table vertical vibration test device

Abstract

The invention relates to the technical field of large spacecraft vibration tests, in particular to a large single-vibration-table vertical vibration test device which comprises a supporting assembly, a vibration isolation assembly, an expansion table, a vibration table body and a guide assembly. The vibration isolation assembly is installed on the top of the supporting assembly. The expansion table is mounted at the top of the vibration isolation assembly; the top surface of the extension table is used for bearing a test piece; the vibration table body is connected with the expansion table and drives the expansion table to vibrate; the guiding assembly is arranged on the periphery of the supporting assembly and the expansion table in a surrounding mode and used for guiding the expansion table to vibrate in the vertical direction. Compared with a traditional vibration test device, due to the fact that the guide assembly and the supporting assembly are independently designed, when resonance happens to the test piece, large-scale vibration cannot be transmitted to the supporting assembly through the guide assembly, coupling resonance happens to the test piece and the supporting assembly, and the problem that vibration control is out of tolerance is avoided. The vibration isolation assembly can reduce the influence of resonance of the test piece and the expansion table on the supporting assembly.

Description

Technical Field

[0001] The invention relates to the technical field of large spacecraft vibration testing, and in particular to a large single vibration table vertical vibration testing device. Background Art

[0002] Spacecraft vibration test is an effective means to test the reliability and dynamic strength of spacecraft products. It has been widely used in the performance assessment of spacecraft products and is an indispensable test link in the spacecraft development process. Spacecraft vibration test is mainly completed with the help of vibration test equipment. During the test, the spacecraft test piece is installed on the extension table. The vibration control system outputs the driving signal according to the test spectrum required by the test conditions. The vibration table drives the extension table to vibrate, so that the extension table and the test piece vibrate. A vibration control acceleration sensor is arranged on the extension table or the test piece. The acceleration sensor feeds back the detected vibration signal to the vibration control system for comparison and correction with the test input spectrum, so that the driving signal meets the requirements of the test conditions. The vibration test is carried out strictly according to the set input spectrum. For sinusoidal vibration tests, the frequency sweep test is generally carried out according to the set acceleration level, the given frequency range and the sweep rate, such as the acceleration level is 0.1g (g is the acceleration of gravity), the sweep range is 5-100Hz, and the sweep rate is 4 times / minute. When the natural frequency of the test piece is within the frequency sweep range, the test piece will resonate. At this time, the acceleration response of the test piece's structure will be amplified for a short time, and the vibration control system will adjust the size of the drive signal according to the set test spectrum to control the test level within the allowable tolerance range of the test to prevent the test piece from being damaged. When the test level exceeds the allowable tolerance range of the test, the vibration control system controls the vibration test device to stop working for the purpose of protecting the test piece, and the spacecraft vibration test is forced to be interrupted. For high-value test pieces such as spacecraft, even if the test level is controlled within the allowable tolerance range of the test, the difference between it and the vibration input spectrum must be minimized as much as possible to prevent the test overload from damaging the test piece.

[0003] For traditional vibration test equipment, the resonant test piece will transmit the vibration to the support system through the extended table and guide system, causing the support system to resonate or causing the support system and the test piece to produce coupled resonance, which will cause serious interference to the vibration control, resulting in large vibration control deviations or test interruption. Therefore, how to avoid resonance in the support system and avoid coupled resonance between the support system and the test piece has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The invention provides a large-scale single-vibration-table vertical vibration test device, which is used to solve the problem of avoiding resonance of a supporting system and avoiding coupling resonance between the supporting system and a test piece.

[0005] The present invention provides a large single vibration table vertical vibration test device, comprising:

[0006] Support components;

[0007] A vibration isolation assembly is installed on the top of the support assembly;

[0008] An extension table, mounted on the top of the vibration isolation assembly, used to carry the test piece;

[0009] The vibration table body is installed in the support assembly and connected to the expansion table to make the expansion table vibrate;

[0010] The guide assembly is arranged around the outer circumference of the support assembly and the expansion platform, and is used for guiding the expansion platform to vibrate in the vertical direction.

[0011] In some embodiments, the guide assembly includes:

[0012] A constraint frame is arranged around the periphery of the expansion platform;

[0013] Support legs, mounted on the bottom of the constraint frame;

[0014] The linear guide is installed on the inner side of the constraint frame and connected to the outer wall of the expansion platform.

[0015] In some of the embodiments, there are multiple linear guides; at least one linear guide is installed on the upper part of the constraint frame and connected to the upper part of the expansion platform; at least one linear guide is installed on the lower part of the constraint frame and connected to the lower part of the expansion platform.

[0016] In some of the embodiments, a bearing seat is formed on the inner side of the constraining frame, and the bearing seat is disposed below the expansion platform.

[0017] In some of the embodiments, weight-reducing holes are formed on the constraining frame.

[0018] In some of the embodiments, reinforcing ribs are provided on the constraining frame.

[0019] In some embodiments, the support assembly includes:

[0020] A first support seat;

[0021] Second support seat; Vibration isolation components are installed on the tops of the second support seat and the first support seat.

[0022] In some embodiments, the vibration isolation assembly includes:

[0023] A first air spring is installed on the top of the first support seat, and the top is connected to the bottom surface of the expansion platform;

[0024] The second air spring is installed on the top of the second support seat, and the top is connected to the bottom surface of the expansion platform.

[0025] In some embodiments, the docking station includes:

[0026] The bottom plate has a bottom surface connected to the top of the vibration isolation assembly and the moving coil of the vibration table body;

[0027] There are multiple side panels, which are evenly distributed along the circumference of the bottom plate; the bottom end of each side panel is fixedly connected to the edge of the bottom plate;

[0028] A top plate is disposed above the bottom plate, and its edge is fixedly connected to the top of each side plate;

[0029] The reinforcing plates are respectively connected to the bottom plate, the side plates and the top plate.

[0030] The beneficial effects of the present invention are as follows: The large single vibration table vertical vibration test device of the present invention is provided with a support assembly, a vibration isolation assembly, an extension table, a vibration table body and a guide assembly, and the vibration isolation assembly is installed on the top of the support assembly. The extension table is installed on the top of the vibration isolation assembly. The top surface of the extension table is used to carry the test piece. The vibration table body is installed in the support assembly. The vibration table body is connected to the extension table to drive the extension table to vibrate. The guide assembly is arranged around the periphery of the support assembly and the extension table, and is used to guide the extension table to vibrate in the vertical direction. Compared with the traditional vibration test device, since the guide assembly and the support assembly are designed independently of each other and there is no connection relationship, when the test piece resonates, the large-scale vibration will not be transmitted to the support assembly through the guide assembly, thereby avoiding the coupling resonance between the test piece and the support assembly and avoiding the problem of vibration control out-of-tolerance. Although the natural frequency of the support assembly is still affected by the weight of the test piece, the vibration isolation assembly that plays a vibration isolation role can reduce the influence of the resonance of the test piece and the extension table on the support assembly, and avoid causing the resonance of the support assembly. The guide assembly can guide the extension table and the test piece to vibrate in the vertical direction, limit the displacement of the extension table in the horizontal plane, and reduce the horizontal component of the acceleration response. Overall, the actual vibration condition is as close to the vibration input spectrum as possible to ensure the smooth progress of the vibration test. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of a traditional vibration test device;

[0032] Figure 2 It is a structural schematic diagram of some specific embodiments of a large single vibration table vertical vibration test device of the present invention;

[0033] Figure 3 yes Figure 2 A schematic diagram of the structure of the guide assembly in the large single vibration table vertical vibration test device shown;

[0034] Figure 4 yes Figure 2The schematic diagram of the combined structure of the support assembly, vibration isolation assembly, extension table and vibration table body in the large single vibration table vertical vibration test device shown.

[0035] In the accompanying drawings, 100 is a traditional vibration test device; 110 is a support system; 120 is a vibration isolation system; 130 is an extended table; 140 is a vibration table; 150 is a guide system; 200 is a large single vibration table vertical vibration test device; 210 is a support assembly; 211 is a first support seat; 212 is a second support seat; 220 is a vibration isolation assembly; 221 is a first air spring; 222 is a second air spring; 230 is an extended table; 231 is a side plate; 232 is a top plate; 240 is a vibration table body; 250 is a guide assembly; 251 is a constraint frame; 2511 is a weight reduction hole; 2512 is a reinforcing rib; 252 is a support leg; 253 is a linear guide; 254 is a bearing seat. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0037] As described in the background art, the conventional vibration test device 100 includes a support system 110, a vibration isolation system 120, a guide system 150, an extended table 130 and a vibration table 140. Figure 1As shown, the support system 110 is used for the vibration isolation system 120, the guide system 150, the extended table 130 and the vibration table 140. The vibration isolation system 120 is installed on the top of the support system 110. The guide system 150 is installed on the top of the support system 110. The extended table 130 is installed on the top of the support system 110 and the guide system 150. The top surface of the extended table 130 is used to carry the test piece. The vibration table 140 is installed on the support system 110. The vibration table 140 is connected to the extended table 130 and is used to drive the extended table 130 and the test piece to vibrate. The support system 110 can be simplified and equivalent to a single-degree-of-freedom vibration system. According to the natural frequency calculation formula of the support system 110, when the stiffness of the support system 110 is a constant, the greater the bearing mass, the lower the natural frequency of the support system 110. Therefore, the mass of the test piece is related to the natural frequency of the support system 110. For test pieces with smaller mass and lower center of mass, their influence on the natural frequency of the support system 110 can be ignored. However, for test pieces with larger mass and higher center of mass, such as manned spacecraft or cargo spacecraft, the influence of their mass on the natural frequency of the support system 110 cannot be ignored. For the traditional vibration test device 100, the resonant test piece will transmit a large amount of vibration to the support system 110 through the extended table 130 and the guide system 150. When the natural frequency of the support system 110 is close to the natural frequency of the test piece, the two will be coupled and resonated, causing vibration control to exceed the tolerance. Therefore, how to avoid resonance of the support system 110 and avoid coupling resonance between the support system 110 and the test piece has become a technical problem that needs to be solved urgently by those skilled in the art.

[0038] To solve the above problems, refer to Figure 2 , Figure 3 and Figure 4 The present invention provides a large single vibration table vertical vibration test device 200, including a support assembly 210, a vibration isolation assembly 220, an extension table 230, a vibration table body 240 and a guide assembly 250. The vibration isolation assembly 220 is installed on the top of the support assembly 210. The extension table 230 is installed on the top of the vibration isolation assembly 220. The top surface of the extension table 230 is used to carry the test piece. The vibration table body 240 is installed in the support assembly 210. The vibration table body 240 is connected to the extension table 230 to drive the extension table 230 to vibrate. The guide assembly 250 is arranged around the periphery of the support assembly 210 and the extension table 230, and is used to guide the extension table 230 to vibrate in the vertical direction.

[0039] The working process and principle of the large single vibration table vertical vibration test device 200 are as follows:

[0040] First, a test piece with a large mass and a high center of mass, such as a manned spacecraft or a cargo spacecraft, is installed on the top surface of the expansion table 230. Then, the expansion table 230 and the test piece are driven to vibrate with the help of the vibration table body 240. Compared with the traditional vibration test device 100, since the guide assembly 250 and the support assembly 210 are designed independently of each other and there is no connection relationship, when the test piece resonates, a large amount of vibration will not be transmitted to the support assembly 210 through the guide assembly 250, thereby avoiding the coupling resonance between the test piece and the support assembly 210 and avoiding the problem of vibration control out-of-tolerance. Although the natural frequency of the support assembly 210 is still affected by the weight of the test piece, the vibration isolation assembly 220 that plays a vibration isolation role can reduce the impact of the resonance of the test piece and the expansion table 230 on the support assembly 210, and avoid causing the resonance of the support assembly 210. The guide assembly 250 can guide the expansion table 230 and the test piece to vibrate in the vertical direction, limit the displacement of the expansion table 230 in the horizontal plane, and reduce the horizontal component of the acceleration response. On the whole, the actual vibration conditions are made to fit the vibration input spectrum as closely as possible to ensure smooth vibration testing.

[0041] Specifically, in the example, Figure 2 and Figure 3 As shown, the guide assembly 250 includes a constraint frame 251, a support leg 252 and a linear guide 253. The constraint frame 251 is arranged around the outer periphery of the expansion platform 230. The support leg 252 is installed at the bottom of the constraint frame 251, and is used to support the constraint frame 251 and the linear guide 253. The linear guide 253 is installed on the inner side of the constraint frame 251 and is fixedly connected to the outer wall of the expansion platform 230. The constraint frame 251 and the linear guide 253 cooperate to guide the expansion platform 230 and the test piece to vibrate in the vertical direction, limit the displacement of the expansion platform 230 in the horizontal plane, and reduce the horizontal component of the acceleration response.

[0042] It should be noted that the constraint frame 251 and the support legs 252 constitute the support structure of the linear guide 253, and the natural frequency of the support structure is not related to the weight of the test piece. Although it is inevitable that the resonant test piece and the expansion table 230 will transmit a large amount of vibration to the support structure composed of the constraint frame 251 and the support legs 252 through the linear guide 253, since the natural frequency of the support structure (greater than 100Hz) is higher than the scanning frequency of the vibration test (less than or equal to 100Hz), the resonance of the test piece within the frequency sweep range will not cause the resonance of the support structure, thus avoiding the coupled resonance of the test piece and the guide assembly 250.

[0043] Preferably, the orthographic projection of the constraint frame 251 from top to bottom is a quadrilateral, hexagonal or octagonal structure, which has high strength and rigidity. Two or more weight-reducing holes 2511 are respectively formed on one side, two sides, three sides or four sides of the constraint frame 251 to reduce the weight of the constraint frame 251, so that the constraint frame 251 and the guide assembly 250 are lightweight in design, which is conducive to the position transfer of the guide assembly 250. Three or more reinforcing ribs 2512 are respectively arranged on the other side, two sides, three sides or four sides of the constraint frame 251 to improve the overall rigidity and strength of the constraint frame 251.

[0044] Preferably, there are three, four or five support legs 252, which are evenly installed at the bottom of the constraint frame 251 along the circumference of the constraint frame 251. Flanges are provided at the top and bottom of each support leg 252 to increase the contact area during connection, thereby improving the stability of the connection.

[0045] Preferably, there are multiple linear guides 253. At least one linear guide 253 is installed on the upper part of the constraint frame 251 and connected to the upper part of the expansion table 230. At least one linear guide 253 is installed on the lower part of the constraint frame 251 and connected to the lower part of the expansion table 230. The multiple linear guides 253 are distributed in two layers, upper and lower, to guide the expansion table 230 and the test piece to vibrate in the vertical direction to the maximum extent, to limit the displacement of the expansion table 230 in the horizontal plane to the maximum extent, and to further reduce the horizontal component of the acceleration response. In addition, the linear guides 253 distributed in the upper and lower layers significantly improve the anti-overturning performance of the expansion table 230. For test pieces with a larger weight and a higher center of mass or eccentric test pieces, the anti-overturning performance of the expansion table 230 is a key performance indicator to ensure the normal conduct of the vibration test. Specifically, there are sixteen linear guides 253. Every four linear guides 253 are installed on the inner side surface of each side of the constraint frame 251 provided with the reinforcing rib 2512, and two of the four linear guides 253 are located at the upper layer, and the other two linear guides 253 are located at the lower layer.

[0046] Preferably, each linear guide 253 is a linear bearing, including a sleeve and a lifting shaft. The lifting shaft is fixedly connected to the outer wall of the expansion platform 230 through a connecting plate, and the sleeve is vertically installed on the inner wall of the constraint frame 251.

[0047] It should be pointed out that if Figure 3As shown, when the expansion table 230 is in an idle state, in order to reduce the load of each linear guide 253, one, two, three or four bearing seats 254 are formed along the circumferential direction on the inner side of the constraint frame 251. Each bearing seat 254 is located on the inner side of each side of the constraint frame 251 provided with the reinforcing rib 2512. Moreover, the bearing seat 254 is arranged below the expansion table 230 to support the expansion table 230 when it is in an idle state. In addition, the bearing seat 254 can be detachably connected to the lifting device, so that the expansion table 230 and the guide assembly 250 can be lifted as a whole for position transfer.

[0048] Specifically, in the example, Figure 2 and Figure 4 As shown, the support assembly 210 includes a first support seat 211 and a second support seat 212. A vibration isolation assembly 220 is installed on the top of the second support seat 212 and the first support seat 211. The vibration isolation assembly 220 includes a first air spring 221 and a second air spring 222. The first air spring 221 is installed on the top of the first support seat 211, and the top is connected to the bottom surface of the expansion platform 230. The second air spring 222 is installed on the top of the second support seat 212, and the top is connected to the bottom surface of the expansion platform 230.

[0049] Preferably, a notch is provided at the upper portion of the outer side of the first support seat 211 to reduce the weight of the first support seat 211, thereby facilitating the position transfer of the first support seat 211. Four or more reinforcing ribs 2512 are provided in the notch to ensure the rigidity and strength of the first support seat 211. A weight-reducing hole 2511 is formed at the upper and lower portions of the second support seat 212 to reduce the weight of the second support seat 212, thereby facilitating the position transfer of the second support seat 212.

[0050] Preferably, there are two first support seats 211 and two second support seats 212, which are alternately arranged along the circumference of the constraint frame 251. Each first support seat 211 is used as the ear axis of the expansion platform 230 and the support seat of the vibration isolation assembly 220, while each second support seat 212 is used as the support seat of the vibration isolation assembly 220. Correspondingly, there are four first air springs 221, of which two first air springs 221 are respectively installed on the top of one of the first support seats 211, and the top is fixedly connected to the bottom surface of the expansion platform 230. The other two first air springs 221 are respectively installed on the top of another first support seat 211, and the top is fixedly connected to the bottom surface of the expansion platform 230. There are four second air springs 222, of which two second air springs 222 are respectively installed on the top of one of the second support seats 212, and the top is fixedly connected to the bottom surface of the expansion platform 230. The other two second air springs 222 are respectively installed on the top of another second support seat 212, and the top is fixedly connected to the bottom surface of the expansion platform 230. The first air spring 221 and the second air spring 222 play a role of vibration isolation, reducing the influence of the resonance of the test piece and the expansion platform 230 on the support assembly 210, and avoiding causing the resonance of the support assembly 210.

[0051] Specifically, in the example, Figure 2 and Figure 4 As shown, the expansion platform 230 as a whole includes a bottom plate, a plurality of side plates 231, a top plate 232 and a plurality of reinforcing plates. The bottom surface of the bottom plate is respectively connected to the top of the first air spring 221 and the second air spring 222 of the vibration isolation assembly 220. The plurality of side plates 231 are evenly distributed along the circumference of the bottom plate. The bottom end of each side plate 231 is fixedly connected to the edge of the bottom plate. The top plate 232 is arranged above the bottom plate, and the edge is fixedly connected to the top of each side plate 231. A mounting hole for mounting the test piece is arranged on the top plate 232. The bottom plate, the plurality of side plates 231 and the top plate 232 constitute a box structure. The expansion platform 230 with a box structure replaces the traditional flat expansion table 130. Under the same weight, the box structure increases the natural frequency of the expansion platform 230, the edge of the table is not easily deformed due to vibration, and the acceleration response of the edge of the table is consistent with the acceleration response of the middle of the table, which ensures that the acceleration response of the entire table has better uniformity. Each reinforcement plate is disposed inside the box structure and is connected to the bottom plate, the side plate 231 and the top plate 232 respectively to improve the rigidity and strength of the expansion platform 230 as a whole.

[0052] Preferably, the expansion platform 230 is projected downward from top to bottom in a quadrilateral, hexagon or octagon. Correspondingly, the bottom plate and the top plate 232 are quadrilateral, hexagon or octagon, and the side plates 231 are four, six or eight.

[0053] Specifically, in the exemplary embodiment, the vibration table body 240 is provided with a dynamic coil. The dynamic coil is connected to the bottom plate of the expansion table 230 and is used to drive the expansion table 230 to vibrate. Specifically, when conducting a test, the vibration control system outputs a driving signal according to the test spectrum required by the test conditions, and after being amplified by the power amplifier, the dynamic coil drives the expansion table 230 and the test piece to vibrate.

[0054] It has been verified by tests that the large single-vibration table vertical vibration test device 200 is suitable for vibration testing of spacecraft products with a weight of more than 10 tons and a center of mass height of more than 3 meters. In actual working conditions, for a 40-ton vertical vibration test system, the vibration table body 240 is an electric vibration table that can generate a thrust of 40 tons, and the extension table 230 adopts an octagonal box structure with a relative parallel edge spacing of 3 meters. The extension table 230 is cast from a magnesium alloy, and the weight of the extension table 230 is about 2.6 tons. The natural frequency of the extension table 230 is about 220Hz. The guide assembly 250 includes 16 linear bearings, which are distributed in two layers, with an anti-overturning moment of about 170kNm. The natural frequency of the support structure composed of the constraint frame 251 and the support leg 252 is about 120Hz, which is higher than the maximum scanning frequency of the vibration test of 100Hz. The bearing capacity of the vibration isolation assembly 220 is about 25 tons, including four first air springs 221 and four second air springs 222.

[0055] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0059] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A large single vibration table vertical vibration test device, characterized in that: include: Support components; A vibration isolation assembly is installed on the top of the support assembly; An extension table, mounted on the top of the vibration isolation assembly, for carrying the test piece; A vibration table body is installed in the support assembly and connected to the expansion table to make the expansion table vibrate; The guide assembly is arranged around the outer circumference of the support assembly and the expansion platform, and is used for guiding the expansion platform to vibrate in a vertical direction.

2. The large single vibration table vertical vibration test device according to claim 1 is characterized in that: The guide assembly comprises: A constraint frame, arranged around the periphery of the expansion platform; Support legs, mounted on the bottom of the constraint frame; A linear guide is installed on the inner side of the constraint frame and connected to the outer wall of the expansion platform.

3. The large single vibration table vertical vibration test device according to claim 2 is characterized in that: There are multiple linear guides; at least one linear guide is installed on the upper part of the constraint frame and connected to the upper part of the expansion platform; at least one linear guide is installed on the lower part of the constraint frame and connected to the lower part of the expansion platform.

4. The large single vibration table vertical vibration test device according to claim 2 is characterized in that: A bearing seat is formed on the inner side of the constraint frame, and the bearing seat is arranged below the expansion platform.

5. The large single vibration table vertical vibration test device according to claim 2 is characterized in that: The constraint frame is formed with weight-reducing holes.

6. The large single vibration table vertical vibration test device according to claim 2 is characterized in that: The constraint frame is provided with reinforcing ribs.

7. The large single vibration table vertical vibration test device according to any one of claims 1 to 6, characterized in that: The support assembly comprises: A first support seat; A second supporting seat; the vibration isolation assembly is installed on the top of the second supporting seat and the first supporting seat.

8. The large single vibration table vertical vibration test device according to claim 7 is characterized in that: The vibration isolation assembly comprises: A first air spring is installed on the top of the first support seat, and the top is connected to the bottom surface of the expansion platform; The second air spring is installed on the top of the second support seat, and the top is connected to the bottom surface of the expansion platform.

9. The large single vibration table vertical vibration test device according to any one of claims 1 to 6, characterized in that: The expansion platform comprises: A bottom plate, the bottom surface of which is connected to the top of the vibration isolation assembly and the moving coil of the vibration table body; There are multiple side panels, which are evenly distributed along the circumference of the bottom plate; the bottom end of each side panel is fixedly connected to the edge of the bottom plate; A top plate, arranged above the bottom plate, with an edge fixedly connected to the top of each of the side plates; The reinforcing plates are respectively connected to the bottom plate, the side plates and the top plate.

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