CN103017993A - Novel multi-axis force controlling vibration test fixture - Google Patents

Abstract

The invention provides a novel multi-axis force controlling vibration test fixture which has a separated structure and comprises an upper fixture which is connected to a whole through screws, a tri-direction force sensor and a lower fixture, wherein the upper fixture and the tri-direction force sensor are arranged on the lower fixture, the upper fixture is connected with the tri-direction force sensor, the lower fixture comprises a lower fixture bottom interface; the tri-direction force sensor is used to measure the interfacial forces in three directions between a satellite and the fixture in the process of a satellite multi-axis vibration test, and feedbacks to a measuring system to achieve a force limiting control under the multi-axis vibration test. The novel multi-axis force controlling vibration test fixture solves technical problems of satellite multi-axis and force controlling vibration test fixture designing, and utilizes the separated fixture structure form to enable the first order resonance frequency of the fixture to be 3 to 5 times higher than that of the satellite, and the high strength and stiffness provides guarantees for the safe implementation of the satellite multi-axis and force controlling vibration test.

Description

A new multi-axis force-controlled vibration test fixture

technical field

The invention relates to a satellite multi-axis force-controlled vibration test fixture, especially belongs to the design field of multi-axis vibration, force-controlled vibration test and fixture, and specifically relates to a novel multi-axis force-controlled vibration test fixture.

Background technique

At present, the ground mechanical vibration test in the aerospace field is mainly a unidirectional acceleration response control method. This method is relatively easy to implement and low in cost, so it is widely used in spacecraft mechanical vibration tests, but it is difficult to avoid under-testing and over-testing during the test process. . In order to overcome under-testing and over-testing and ensure product reliability, multi-axis and force-controlled vibration test technologies are gradually being applied. The multi-axis vibration test technology is based on the premise that the uniaxial vibration test cannot completely simulate the vibration environment suffered by the satellite during the launch process. The multi-point and multi-directional excitation method is used to simulate the actual vibration environment of the satellite. Potential faults not found in the test can improve the adaptability and reliability of the product to the mechanical environment. The force-limited vibration test technology is to limit the interface force while the acceleration is controlled. When the interface force reaches the specified amount, the acceleration is controlled to actively sink, so as to avoid over-testing. This is a control method that combines acceleration control and force response control. It can effectively solve the defect of single acceleration control. The multi-axis force-controlled vibration test fixture is the main component of the multi-axis, force-limited vibration test, and it plays the role of transmitting and measuring the interface force. It is very difficult to design a fixture that can simultaneously complete satellite multi-axis and force-controlled vibration tests. It is required that the fixture can withstand vibration tests in multiple directions at the same time. It has high strength, high stiffness, and the first-order resonance frequency is higher than that of the satellite. The resonance frequency is 3-5 times, which makes the fixture safe and reliable during the vibration test.

Contents of the invention

Aiming at the defects in the prior art, in order to solve the problem that the interface between the satellite and the vibrating table does not match, and it is required to measure the interface force between the satellite and the fixture during the test, and to realize force limit control, the present invention provides a new type of multi-axis force limiter. Vibration test fixture. Utilizing the technical scheme provided by the invention, the satellite multi-axis and force-controlled vibration tests can be carried out simultaneously.

According to one aspect of the present invention, a new type of multi-axis force-controlled vibration test fixture is provided, which has a separate structure and includes an upper fixture, a 3-direction force sensor, and a lower fixture connected as a whole by screws, wherein the upper The fixture and the 3-way force sensor are arranged on the lower fixture, the upper fixture is connected to the 3-way force sensor, and the lower fixture includes a bottom interface of the lower fixture; the 3-way force sensor is used to measure the multi-axis vibration of the satellite During the test, the interface force in three directions between the satellite and the fixture is fed back to the measurement system to realize the force limit control under the multi-axis vibration test.

Preferably, the lower fixture is provided with a central through hole, and the central through hole enables the first-order vibration frequency of the multi-axis force-controlled vibration test fixture to be 935 Hz.

Preferably, the 3-direction force sensors are symmetrically distributed on the lower clamp.

Preferably, the upper clamp is I-shaped with a height of 73mm.

Preferably, the number of the 3-direction force sensors is 4, and there are 4 square bosses on the upper plane of the lower fixture, the 3-direction force sensors are installed on the square bosses, the lower fixture and the 3-direction force sensors The threaded hole of the sensor of the 3-way force sensor and the through hole of the lower clamp of the lower clamp are installed in the form of countersunk screws.

Preferably, the size of the central through hole is φ280mm.

Preferably, the bottom interface of the lower fixture includes a bottom φ558.8mm interface.

Preferably, the bottom interface of the lower fixture includes a bottom φ406.4mm interface.

Preferably, the mass is 160Kg, the height is 250mm, and the maximum external dimension is φ660mm.

Preferably, four φ6 product installation holes are provided on the upper surface of the upper fixture.

Compared with the prior art, the present invention solves the technical difficulties in the design of satellite multi-axis and force-controlled vibration test fixtures, and adopts a separate fixture structure, so that the first-order resonance frequency of the fixture is 3-5 times higher than that of satellites, and the strength is high. , large rigidity provides a guarantee for the safe implementation of multi-axis and force-controlled vibration tests of satellites.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is a schematic structural view of a novel multi-axis force-controlled vibration test fixture provided according to the present invention;

FIG. 2 is a schematic structural view of parts of the novel multi-axis force-controlled vibration test fixture shown in FIG. 1 .

In the figure: 1 is the vibration test fixture, 2 is the upper fixture, 3 is the 3-way force sensor, 4 is the lower fixture, 5 is the threaded hole of the sensor, 6 is the through hole of the lower fixture, 7 is the lower plane, 8 is a square boss, 9 is the central through hole, and 10 is the bottom interface of the lower fixture. Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

As shown in Fig. 1 and Fig. 2, the vibration test fixture 1 provided according to the present invention is mainly used in the satellite multi-axis force-controlled vibration test to connect the satellite with the vibration table, and can measure the interface force between the satellite and the fixture in the test process to realize Force limit control. Specifically, the vibration test fixture 1 adopts a separate type and is connected as a whole by screws, and is mainly composed of an upper fixture 2 , a three-way force sensor 3 , and a lower fixture 4 . In order to strengthen the rigidity of the fixture, the structure of the upper fixture 2 is I-shaped, and the size of the column of the upper fixture 2 is smaller than that of the upper plate. During the axial vibration test, the interface force between the satellite and the fixture is fed back to the measurement system to realize the force limit control under the multi-axial vibration test. Since the connection of the 3-way force sensor 3 is the sensor threaded hole 5, if the lower fixture 4 also uses the threaded hole, the manufacturing accuracy of the lower fixture will be extremely high, which greatly increases the difficulty of assembly, so the lower fixture uses the lower fixture through hole 6, The 3-direction force sensor 3 is connected to the 3-direction force sensor 3 through the countersunk head of the lower plane 7. In order to reduce the processing amount of the non-installation surface, 4 square bosses 8 are designed on the lower fixture 4 for the installation of the 3-direction force sensor. The center through hole 9 The quality of the fixture is reduced, so that the first-order resonance frequency of the fixture is as high as 935Hz, which greatly exceeds the design index of the fixture for the satellite multi-axis force-controlled vibration test.

More specifically, as shown in Figure 1, when the satellite is performing a multi-axial force limit vibration test, the vibration test fixture 1 is installed on the vibration table through the bottom interface 10 of the lower fixture (including the bottom φ558.8 and φ406.4mm interfaces). The product is installed on the vibration test fixture 1 through 16 φ6 holes on the upper surface of the upper fixture 2. The fixture structure adopts a separate form, with a height of 250mm, a maximum external dimension of φ660mm, a mass of 160Kg, and a first-order resonance frequency as high as 935Hz, which greatly exceeds the highest frequency required by satellite vibration tests.

Further, as shown in Figure 2, the upper fixture 2 is I-shaped, with a height of 73mm. This structural form is used to facilitate the assembly of the product with the upper fixture 2 and the 3-direction force sensor 3, effectively solving the mismatch between the product and the sensor interface, The problem of interference between the product and the fixture, the 3-direction force sensor 3 is used to measure the interface force in three directions, and the measured force signal is fed back to the test system, so as to realize the force limit control, and the symmetrical distribution of the four 3-direction force sensors 3 reduces the Eccentric, so that the force of each 3-direction force sensor 3 is uniform, reducing the probability of equipment damage. The four square bosses 8 of the lower fixture 4 are used to install the 3-direction force sensor 3, reducing the amount of processing on the non-installation surface. The lower fixture The installation of the 2- and 3-direction force sensors 3 is in the form of countersunk screws, and the connection method of through holes and threaded holes greatly reduces the difficulty of assembly and also reduces the requirements for machining accuracy.

The vibration test fixture provided by the present invention has the advantages of compact structure, high strength, high rigidity and strong bearing capacity, solves the technical difficulties in the design of satellite multi-axis force limit vibration test fixture, has low manufacturing cost and strong applicability, and has achieved good results. economic effect. Moreover, the first-order frequency of the fixture is 3-5 times higher than that of the satellite, which greatly improves the safety and reliability of the multi-axis force limit vibration test of the satellite.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (10)

1. A novel multi-axis force-controlled vibration test fixture is characterized in that the structure is a separate type, including an integral upper fixture, a 3-direction force sensor, and a lower fixture connected by screws, wherein the upper fixture and The 3-direction force sensor is set on the lower fixture, the upper fixture is connected to the 3-direction force sensor, and the lower fixture includes the bottom interface of the lower fixture; the 3-direction force sensor is used to measure the satellite multi-axis vibration test process The interface force in three directions between the satellite and the fixture is then fed back to the measurement system to realize the force limit control under the multi-axis vibration test. 2. The novel multi-axis force-controlled vibration test fixture according to claim 1, wherein the lower fixture is provided with a central through hole, and the central through-hole makes the first-order vibration frequency of the multi-axis force-controlled vibration test fixture 935Hz. 3. The novel multi-axis force-controlled vibration test fixture according to claim 1, characterized in that the 3-direction force sensors are symmetrically distributed on the lower fixture. 4. The novel multi-axis force-controlled vibration test fixture according to claim 1, wherein the upper fixture is I-shaped and has a height of 73mm. 5. The novel multi-axis force-controlled vibration test fixture according to claim 1, wherein the quantity of the 3-direction force sensor is 4, and there are 4 square bosses on the upper plane of the lower fixture, and the The 3-direction force sensor is installed on the square boss, and the lower clamp and the 3-direction force sensor are installed through the sensor threaded hole of the 3-direction force sensor and the lower clamp through hole of the lower clamp using countersunk screws. 6. The novel multi-axis force-controlled vibration test fixture according to claim 2, characterized in that the size of the central through hole is φ280mm. 7. The novel multi-axis force-controlled vibration test fixture according to claim 1, characterized in that the bottom interface of the lower fixture includes a bottom φ558.8mm interface. 8. The novel multi-axis force-controlled vibration test fixture according to claim 1, characterized in that the bottom interface of the lower fixture includes a bottom φ406.4mm interface. 9. The novel multi-axis force-controlled vibration test fixture according to claim 1, characterized in that the mass is 160Kg, the height is 250mm, and the maximum external dimension is φ660mm. 10. The novel multi-axis force-controlled vibration test fixture according to claim 1, characterized in that four φ6 product mounting holes are provided on the upper surface of the upper fixture.

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