Electromagnetic electro-hydraulic composite vibration device, using method thereof and vibration table

Abstract

The invention provides an electromagnetic electro-hydraulic composite vibration device which comprises a cylinder body, a magnetic cylinder ring arranged on the side edge of the cylinder body in the axial direction and a piston penetrating through the cylinder body in the axial direction, an excitation piece is arranged in the magnetic cylinder ring, and a driving coil is arranged on the piston. The middle of the piston protrudes outwards in the axial direction to form a stress protrusion, the stress protrusion abuts against the cylinder body in the radial direction, the driving coil is used for being matched with an excitation piece to drive the piston to move in the axial direction, and the cylinder body is hollow to form an upper hydraulic cavity and a lower hydraulic cavity which are located on the two sides of the stress protrusion. The cylinder body is provided with a first hydraulic runner and a second hydraulic runner which are used for being communicated with the upper hydraulic cavity and the lower hydraulic cavity respectively. According to the electromagnetic electro-hydraulic composite vibration device, the using method thereof and the vibration table, electromagnetic vibration and electro-hydraulic vibration can be achieved on one vibration table, the bandwidth coverage is wide, and compared with independent operation of two sets of equipment, the cost is lower, and the occupied area is smaller.

Description

Technical Field

[0001] The invention relates to the field of test devices, and in particular to an electromagnetic electro-hydraulic composite vibration device and a use method thereof, and a vibration table. Background Art

[0002] At present, testing units and reliability laboratories at home and abroad usually use electromagnetic vibration tables to simulate high-frequency and high-acceleration vibrations such as blade fatigue tests, satellite vibration tests, and battery pack vibration tests. Electrohydraulic vibration tables are usually used to simulate low-frequency and large-displacement vibrations such as packaging and transportation tests of packaged items, large buildings, and earthquake simulation tests of high-voltage electrical equipment. The electromagnetic vibration table indicators given by various domestic manufacturers are approximately 2-2500Hz, with displacements of 51mm and 76mm, and the high standard can reach 100mm, but the electromagnetic vibration table cannot meet the requirements of some packaging and transportation tests with displacements exceeding 100mm, earthquake simulation tests with 0.5Hz vibration start and displacements of 200mm, 300mm or even higher. The electrohydraulic vibration table indicators given by various domestic manufacturers are approximately 0.1-100Hz, with an acceleration of 5g, but the electrohydraulic vibration table cannot meet the requirements of some tests such as battery packs that require high-frequency and high-acceleration vibration tests.

[0003] In view of this, it is necessary to improve the existing vibration device to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide an electromagnetic electro-hydraulic composite vibration device to solve the problem that the existing vibration table cannot integrate the two working modes of electro-hydraulic vibration and electromagnetic vibration.

[0005] To achieve the above-mentioned purpose, the present invention provides an electromagnetic electro-hydraulic composite vibration device, which includes a cylinder body, a magnetic cylinder ring axially arranged on the side of the cylinder body, and a piston axially penetrating the cylinder body, an excitation component is arranged in the magnetic cylinder ring, a driving coil is arranged on the piston, a force-bearing protrusion is axially protruding outward from the middle part of the piston, the force-bearing protrusion is radially abutted against the cylinder body, the driving coil is used to cooperate with the excitation component to drive the piston to move axially, the cylinder body is hollowly arranged to form an upper hydraulic chamber and a lower hydraulic chamber located on both sides of the force-bearing protrusion, and the cylinder body is provided with a first hydraulic channel and a second hydraulic channel respectively connected to the upper hydraulic chamber and the lower hydraulic chamber.

[0006] As a further improvement of the present invention, the electromagnetic electro-hydraulic composite vibration device also includes an O-type servo valve connecting the first hydraulic channel and the second hydraulic channel. When the O-type servo valve is closed, the first hydraulic channel and the second hydraulic channel are disconnected from the external hydraulic station. When the O-type servo valve is working, the first hydraulic channel and the second hydraulic channel are connected to the external hydraulic station.

[0007] As a further improvement of the present invention, the cylinder body is also provided with a third hydraulic channel and a fourth hydraulic channel respectively used to communicate with the upper hydraulic chamber and the lower hydraulic chamber, and the electromagnetic electro-hydraulic composite vibration device also includes an on-off valve connecting the third hydraulic channel and the fourth hydraulic channel. When the on-off valve is closed, the third hydraulic channel and the fourth hydraulic channel are connected to an external hydraulic station. When the on-off valve is working, the third hydraulic channel and the fourth hydraulic channel are disconnected from the external hydraulic station. When the O-type servo valve is working, the on-off valve works; when the excitation component and the drive coil are energized, the O-type servo valve is closed and the on-off valve is closed.

[0008] As a further improvement of the present invention, the electromagnetic electro-hydraulic composite vibration device also includes a magnetic cylinder bottom arranged between the cylinder body and the magnetic cylinder ring, and a magnetic cylinder cover arranged on the side of the magnetic cylinder ring away from the cylinder body.

[0009] As a further improvement of the present invention, the number of the magnetic cylinder rings is two, and the two magnetic cylinder rings are respectively arranged at two ends of the cylinder body along the axial direction.

[0010] As a further improvement of the present invention, two excitation components are provided in each magnetic cylinder ring, and the two excitation components are spaced apart in the axial direction.

[0011] As a further improvement of the present invention, a heat dissipation channel facing the excitation component is opened on the magnetic cylinder ring, and the electromagnetic electro-hydraulic composite vibration device also includes a connecting channel connecting the heat dissipation channels on both sides. The number of the connecting channels is multiple, and the multiple connecting channels are arranged in an array around the cylinder body.

[0012] As a further improvement of the present invention, the electromagnetic electro-hydraulic composite vibration device also includes a cover arranged on the side of the magnetic cylinder ring away from the cylinder body, and the cover covers at both ends are respectively connected to the heat dissipation channels on the magnetic cylinder rings on both sides, one of the cover covers is provided with an air inlet, and the other cover cover is provided with an air outlet.

[0013] As a further improvement of the present invention, the electromagnetic electro-hydraulic composite vibration device also includes a static pressure support assembly, which includes a guide sleeve radially abutting against the piston, a guide sleeve arranged on the guide sleeve close to the magnetic cylinder ring to abut against the piston, and a throttle, a static pressure chamber and an oil return chamber connected to the static pressure chamber are recessed on the side of the guide sleeve close to the piston ring, the throttle and the static pressure chamber are connected via a static pressure channel, and an oil supply channel connected to the throttle is opened on the cylinder body.

[0014] The present invention also provides a working method of the electromagnetic, electro-hydraulic composite vibration device as described above, wherein the working method of the electromagnetic, electro-hydraulic composite vibration device has at least two working modes, including:

[0015] High-frequency and high-acceleration excitation mode: the excitation element is supplied with direct current, the drive coil is supplied with alternating current, the O-type servo valve is closed, the first hydraulic flow channel and the second hydraulic flow channel are disconnected from the external hydraulic station, the on-off valve is closed, and the third hydraulic flow channel and the fourth hydraulic flow channel are connected to the external hydraulic station;

[0016] Ultra-low frequency large displacement excitation mode: the excitation component and the drive coil are not energized, the O-type servo valve works, the first hydraulic flow channel and the second hydraulic flow channel are connected to the external hydraulic station, the on-off valve works, and the third hydraulic flow channel and the fourth hydraulic flow channel are disconnected from the external hydraulic station.

[0017] As a further improvement of the present invention, in two working modes, namely, the high-frequency high-acceleration excitation mode and the ultra-low-frequency large-displacement excitation mode, oil is supplied to the static pressure support assembly through a hydraulic station.

[0018] The present invention also provides a vibration test bench, which includes the electromagnetic-electro-hydraulic composite vibration device as described above.

[0019] The beneficial effects of the present invention are as follows: the electromagnetic electro-hydraulic composite vibration device and its use method and vibration table of the present invention can realize electromagnetic vibration and electro-hydraulic vibration on one vibration table, and have a wide bandwidth coverage. Compared with two sets of equipment operating independently, the cost is lower and the footprint is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the electromagnetic electro-hydraulic composite vibration device of the present invention;

[0022] Figure 2 It is a partial cross-sectional structural schematic diagram of the electromagnetic electro-hydraulic composite vibration device of the present invention;

[0023] Figure 3 It is a front cross-sectional structural schematic diagram of the electromagnetic electro-hydraulic composite vibration device of the present invention;

[0024] Figure 4 yes Figure 3 A schematic diagram of the enlarged structure of the middle area A;

[0025] Figure 5 It is a front structural schematic diagram of the piston of the electromagnetic electro-hydraulic composite vibration device of the present invention;

[0026] Figure 6 It is a principle diagram of the working method of the electromagnetic electro-hydraulic composite vibration device of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figures 1 to 5 As shown, the vibration test bench includes an electromagnetic electro-hydraulic composite vibration device 100, a workbench for placing workpieces, a base for supporting the electromagnetic electro-hydraulic composite vibration device 100, and other devices, which need to be able to realize complete test functions.

[0031] The electromagnetic electro-hydraulic composite vibration device 100 includes a cylinder body 1, a magnetic cylinder ring 2 axially arranged on the side of the cylinder body 1, a magnetic cylinder bottom 3 arranged between the cylinder body 1 and the magnetic cylinder ring 2, a magnetic cylinder cover 4 arranged on the side of the magnetic cylinder ring 2 away from the cylinder body 1, a piston 5 axially penetrating the cylinder body 1, a cover 6 arranged on the side of the magnetic cylinder ring 2 away from the cylinder body 1, an O-type servo valve, an on-off valve, a static pressure support assembly 7, a connecting flow channel 8, a hydraulic station and a controller.

[0032] The cylinder body 1 is arranged in the middle so that the piston 5 can pass through.

[0033] There are two magnetic cylinder rings 2, which are respectively arranged at two ends of the cylinder body 1 in the axial direction. There are excitation components 21 in the magnetic cylinder ring 2. In this embodiment, there are two excitation components 21 in each magnetic cylinder ring 2, and the two excitation components 21 are arranged at intervals in the axial direction.

[0034] The piston 5 is provided with a driving coil 51. In this embodiment, there are two driving coils 51, one at each end of the piston 5. Each driving coil 51 is used to correspond to the excitation member 21 in the corresponding magnetic cylinder ring 2. The driving coil 51 is formed by winding enameled wire in the same direction and curing it on the piston 5 through epoxy. The driving coil 51 is used to cooperate with the excitation member 21 to drive the piston 5 to move axially.

[0035] When the test requires high-frequency and high-acceleration excitation, the vibration test bench is equivalent to an electromagnetic vibration bench. The excitation component 21 is energized to generate a circular magnetic field along the drive coil 51. The drive coil 51 on the piston 5 rod is energized with external alternating current and generates an up and down reciprocating motion under the action of the magnetic field.

[0036] A force-bearing protrusion 52 is axially extended outward from the middle of the piston 5, and the force-bearing protrusion 52 is radially abutted against the cylinder body 1. The cylinder body 1 is hollow and has an upper hydraulic chamber 15 and a lower hydraulic chamber 16 located on both sides of the force-bearing protrusion 52, wherein the upper hydraulic chamber 15 is located above the lower hydraulic chamber 16.

[0037] The cylinder body 1 is provided with a first hydraulic channel 11 and a second hydraulic channel 12 for communicating with the upper hydraulic chamber 15 and the lower hydraulic chamber 16, respectively, and the first hydraulic channel 11 is located above the second hydraulic channel 12. The O-type servo valve is used to connect the first hydraulic channel 11 and the second hydraulic channel 12. When the O-type servo valve is closed, the first hydraulic channel 11 and the second hydraulic channel 12 are disconnected from the external hydraulic station. When the O-type servo valve is working, the first hydraulic channel 11 and the second hydraulic channel 12 are connected to the external hydraulic station through the oil circuit, and the O-type servo valve is used to switch the oil circuit.

[0038] When the test requires ultra-low frequency large displacement excitation, the vibration test bench is equivalent to an electro-hydraulic vibration bench, and the external hydraulic station supplies oil to the oil circuit. After the O-type servo valve receives the controller signal, the valve core switches to make the first hydraulic flow channel 11 and the second hydraulic flow channel 12 reciprocate oil supply, that is, the amount of hydraulic oil in the upper hydraulic chamber 15 and the lower hydraulic chamber 16 changes continuously to drive the force-bearing protrusion 52 to move axially, thereby achieving the effect of driving the piston 5 to reciprocate.

[0039] During the electro-hydraulic servo vibration process, when we turn on the power, we need an O-type servo valve to ensure that the oil circuit always maintains a pressure storage state, so it is not advisable to select a servo valve with a neutral ABPT connection. However, this will result in the upper hydraulic chamber 15 and the lower hydraulic chamber 16 having a constant pressure when high-frequency and high-acceleration excitation is required, and the piston 5 cannot be driven axially by electromagnetic force.

[0040] Therefore, in this embodiment, the cylinder body 1 is further provided with a third hydraulic channel 13 and a fourth hydraulic channel 14 for communicating with the upper hydraulic chamber 15 and the lower hydraulic chamber 16, respectively. The on-off valve is used to connect the third hydraulic channel 13 and the fourth hydraulic channel 14. When the on-off valve is closed, the third hydraulic channel 13 and the fourth hydraulic channel 14 are connected to the external hydraulic station. When the on-off valve is working, the third hydraulic channel 13 and the fourth hydraulic channel 14 are disconnected from the external hydraulic station. When the O-type servo valve is working, the on-off valve is working. In this embodiment, there are two on-off valves, and the hydraulic station has two independent oil return pipelines directly connected to the two on-off valves, and then the on-off valves are connected to the third hydraulic channel 13 and the fourth hydraulic channel 14 one-to-one.

[0041] In this embodiment, the electromagnetic and electro-hydraulic excitation switching is achieved by controlling the opening and closing of the on-off valve, which has a simple principle and strong practicality.

[0042] The magnetic cylinder ring 2 is provided with a heat dissipation channel 22 facing the excitation component 21. There are multiple connecting channels 8, which are arranged in an array around the cylinder body 1. In this embodiment, there are eight connecting channels 8.

[0043] The covers 6 at both ends are respectively communicated with the heat dissipation channels 22 on the magnetic cylinder rings 2 at both sides, one of the covers 6 is provided with an air inlet 61 , and the other cover 6 is provided with an air outlet 62 .

[0044] During high-frequency and high-acceleration excitation, the excitation component 21 generates heat, and the external fan extracts air for forced air cooling. Specifically, air enters along the axially upper cover 6, passes through the heat dissipation channel 22 on the upper magnetic cylinder ring 2, passes through the excitation component 21, and then flows to the heat dissipation channel 22 of the lower magnetic cylinder ring 2 through the connecting channel 8, and is extracted by the fan after passing through the excitation component 21. Among them, the heat dissipation channel 22 and the connecting channel 8 do not pass through the middle oil circuit, and have no effect on the oil temperature. Multiple connecting channels 8 are set to disperse the heat, force concentrated extraction, and have obvious cooling effect.

[0045] like Figure 4As shown, the static pressure support assembly 7 includes a guide sleeve 71 radially abutting against the piston 5, a guide sleeve 71 arranged on the guide sleeve 71 near the magnetic cylinder ring 2 to abut against the piston 5, a throttle 73, and a dust cover 77. A static pressure chamber 74 and an oil return chamber 75 communicating with the static pressure chamber 74 are recessed on the side of the guide sleeve 71 near the piston 5 ring. The throttle 73 and the static pressure chamber 74 are connected through a static pressure channel 76. The cylinder body 1 is provided with an oil supply channel 17 communicating with the throttle 73. The oil return chamber 75 is communicated with the hydraulic station to achieve an oil return effect.

[0046] The dustproof pressure cover 77 is arranged between the guide sleeve 71 and the magnetic cylinder bottom 3. The dustproof pressure cover 77 is provided with a dustproof ring 78 which abuts against the piston 5 to prevent dust from entering the oil circuit.

[0047] The guide sleeve 71 can prevent hydraulic oil from entering the magnetic cylinder ring 2.

[0048] The static pressure support assembly 7 is independently arranged to break through the characteristic of weak anti-eccentric load moment of the traditional vibration table.

[0049] The hydraulic station can supply oil to the hydrostatic support assembly 7. In this embodiment, the O-type servo valve, on-off valve and hydrostatic support assembly 7 all need to be provided with hydraulic oil by the hydraulic station. Multiple hydraulic stations can be set up, or the same hydraulic station can be shared, which is not limited in this embodiment.

[0050] In this embodiment, the controller can control the operation of the on-off valve and the O-type servo valve, and can also control the operation of the hydraulic station to supply oil to the static pressure support assembly 7 .

[0051] like Figure 6 As shown, the working method of the electromagnetic electro-hydraulic composite vibration device 100 has at least two working modes, including:

[0052] High-frequency and high-acceleration excitation mode: the excitation element 21 is supplied with direct current, the drive coil 51 is supplied with alternating current, the O-type servo valve is closed, the first hydraulic channel 11 and the second hydraulic channel 12 are disconnected from the external hydraulic station, the on-off valve is closed, and the third hydraulic channel 13 and the fourth hydraulic channel 14 are connected to the external hydraulic station;

[0053] Ultra-low frequency large displacement excitation mode: the excitation component 21 and the drive coil 51 are not energized, the O-type servo valve works, the first hydraulic channel 11 and the second hydraulic channel 12 are connected to the external hydraulic station, the on-off valve works, and the third hydraulic channel 13 and the fourth hydraulic channel 14 are disconnected from the external hydraulic station.

[0054] In the two working modes of high-frequency high-acceleration excitation mode and ultra-low-frequency large-displacement excitation mode, oil is supplied to the static pressure support assembly 7 through the hydraulic station.

[0055] The electromagnetic electro-hydraulic composite vibration device 100 and its use method and vibration table of the present invention can realize electromagnetic vibration and electro-hydraulic vibration on one vibration table, and has a wide bandwidth coverage. Compared with two sets of equipment operating independently, the cost is lower and the floor space is smaller.

[0056] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An electromagnetic electro-hydraulic composite vibration device, characterized in that: The electromagnetic electro-hydraulic composite vibration device includes a cylinder body, a magnetic cylinder ring axially arranged on the side of the cylinder body, and a piston axially penetrating the cylinder body, an excitation component is arranged in the magnetic cylinder ring, a driving coil is arranged on the piston, a force-bearing protrusion is axially protruding outward from the middle part of the piston, the force-bearing protrusion is radially abutted against the cylinder body, and the driving coil is used to cooperate with the excitation component to drive the piston to move axially, the cylinder body is hollowly arranged to form an upper hydraulic chamber and a lower hydraulic chamber located on both sides of the force-bearing protrusion, and the cylinder body is provided with a first hydraulic flow channel and a second hydraulic flow channel respectively connected to the upper hydraulic chamber and the lower hydraulic chamber.

2. The electromagnetic electro-hydraulic composite vibration device according to claim 1, characterized in that: The electromagnetic electro-hydraulic composite vibration device also includes an O-type servo valve connecting the first hydraulic channel and the second hydraulic channel. When the O-type servo valve is closed, the first hydraulic channel and the second hydraulic channel are disconnected from the external hydraulic station. When the O-type servo valve is working, the first hydraulic channel and the second hydraulic channel are connected to the external hydraulic station.

3. The electromagnetic electro-hydraulic composite vibration device according to claim 2, characterized in that: The cylinder body is also provided with a third hydraulic channel and a fourth hydraulic channel respectively used to communicate with the upper hydraulic chamber and the lower hydraulic chamber. The electromagnetic electro-hydraulic composite vibration device also includes an on-off valve connecting the third hydraulic channel and the fourth hydraulic channel. When the on-off valve is closed, the third hydraulic channel and the fourth hydraulic channel are connected to the external hydraulic station. When the on-off valve is working, the third hydraulic channel and the fourth hydraulic channel are disconnected from the external hydraulic station. When the O-type servo valve is working, the on-off valve works; when the excitation component and the drive coil are energized, the O-type servo valve is closed and the on-off valve is closed.

4. The electromagnetic electro-hydraulic composite vibration device according to claim 1, characterized in that: The electromagnetic electro-hydraulic composite vibration device also includes a magnetic cylinder bottom arranged between the cylinder body and the magnetic cylinder ring, and a magnetic cylinder cover arranged on a side of the magnetic cylinder ring away from the cylinder body.

5. The electromagnetic electro-hydraulic composite vibration device according to claim 1, characterized in that: The number of the magnetic cylinder rings is two, and the two magnetic cylinder rings are respectively arranged at two ends of the cylinder body along the axial direction.

6. The electromagnetic electro-hydraulic composite vibration device according to claim 5, characterized in that: Two excitation components are arranged in each magnetic cylinder ring, and the two excitation components are arranged at intervals along the axial direction.

7. The electromagnetic electro-hydraulic composite vibration device according to claim 5, characterized in that: The magnetic cylinder ring is provided with a heat dissipation channel toward the excitation component, and the electromagnetic electro-hydraulic composite vibration device also includes a connecting channel connecting the heat dissipation channels on both sides. There are multiple connecting channels, and the multiple connecting channels are arranged in an array around the cylinder body.

8. The electromagnetic electro-hydraulic composite vibration device according to claim 7, characterized in that: The electromagnetic electro-hydraulic composite vibration device also includes a cover arranged on the side of the magnetic cylinder ring away from the cylinder body, and the cover at both ends are respectively connected to the heat dissipation channels on the magnetic cylinder rings on both sides, one of the cover covers is provided with an air inlet, and the other cover cover is provided with an air outlet.

9. The electromagnetic electro-hydraulic composite vibration device according to claim 1, characterized in that: The electromagnetic electro-hydraulic composite vibration device also includes a static pressure support assembly, which includes a guide sleeve radially abutting against the piston, a guide sleeve arranged on the guide sleeve close to the magnetic cylinder ring to abut against the piston, and a throttle. A static pressure chamber and an oil return chamber connected to the static pressure chamber are recessed on the side of the guide sleeve close to the piston ring. The throttle and the static pressure chamber are connected via a static pressure channel, and an oil supply channel connected to the throttle is opened on the cylinder body.

10. A working method of the electromagnetic electro-hydraulic composite vibration device according to any one of claims 1 to 9, characterized in that: The working method of the electromagnetic electro-hydraulic composite vibration device has at least two working modes, including: High-frequency and high-acceleration excitation mode: the excitation element is supplied with direct current, the drive coil is supplied with alternating current, the O-type servo valve is closed, the first hydraulic flow channel and the second hydraulic flow channel are disconnected from the external hydraulic station, the on-off valve is closed, and the third hydraulic flow channel and the fourth hydraulic flow channel are connected to the external hydraulic station; Ultra-low frequency large displacement excitation mode: the excitation component and the drive coil are not energized, the O-type servo valve works, the first hydraulic flow channel and the second hydraulic flow channel are connected to the external hydraulic station, the on-off valve works, and the third hydraulic flow channel and the fourth hydraulic flow channel are disconnected from the external hydraulic station.

11. The working method of the electromagnetic electro-hydraulic composite vibration device according to claim 10, characterized in that: In both high-frequency and high-acceleration excitation modes and ultra-low-frequency and large-displacement excitation modes, oil is supplied to the static pressure support assembly through the hydraulic station.

12. A vibration test bench, characterized in that: The vibration test bench comprises the electromagnetic electro-hydraulic composite vibration device as described in any one of claims 1-9.

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