KR101145711B1 - Mechanical ground support equipment for thermal cycling of high stability payload structure - Google Patents

Abstract

The thermal cycle test fixture according to the present invention for thermally testing a test object requiring dimensional stability includes a plurality of mounts for supporting the test object and a beam connecting the mounts, the mounts being capable of positional movement. It is fixed to be prevented, and each of the beams connecting the mounting portions is divided, and each pair of divided beams is connected by a flexure member that absorbs longitudinal length change due to thermal deformation of the beam by bending deformation.

Heat cycle test, fixture, flexure member, heat deformation, stator

Description

TECHNICAL GROUND SUPPORT EQUIPMENT FOR THERMAL CYCLING OF HIGH STABILITY PAYLOAD STRUCTURE}

The present invention relates to a jig design technology for the heat cycle test that simulates the orbital thermal environment during the test of the certification model for space certification in the satellite development procedure, and more specifically, orbit of the high-dimension stabilized structure mounted on the satellite In a thermal cycle test for thermal environmental space certification, the present invention relates to a thermal cycle jig for preventing a structure which is a test object from being affected by planar thermal deformation.

High-dimension stabilizing structures mounted on satellites in outer space are hardly subject to thermal deformation due to actual temperature changes in the orbital environment because they are mounted on main structures made of high modulus composites with a coefficient of thermal expansion close to zero.

In addition, in order to exclude the influence of the thermal environment when mounting the components of the satellite payload to the main structure, iso-static mount is applied to minimize the influence of deformation of the main payload on the components of the satellite payload. (Reduced to about 1/1000) is also known.

Therefore, in order to accurately evaluate the effect of repeated temperature changes on the payload structure by the heat cycle test in the real environment in space, the effect of the heat deformation of the test fixture on the structure should be excluded. An ideal solution is to fabricate a test fixture from a composite material that is the same material as the main structure of the satellite, in which case the cost of producing the fixture is more expensive than the test object.

Therefore, in the heat cycle test of a structure requiring high dimensional stability, even if a jig made of an expensive composite material is not used, it is possible to prevent the heat deformation occurring in the jig affecting the structure that is the test object. A solution is required.

During thermal cycle testing for space certification of high-dimension stabilized structures for satellites, thermal deformations occurring in test fixtures in which the object is mounted may not simulate the composite structures with little thermal expansion in which the high-dimension stabilized structures are actually mounted. In this case, it acts as a cause of lowering structural stability.

High-dimension stability structures for satellites are designed considering launch environment / orbital environment, and high-dimension stability structures are required for heat cycle test fixtures to meet these requirements. Therefore, when deformation is generated from the test jig when the thermal cycle test is not simulated and affects the test object, a load different from the real environment may be applied to the test object, such as a misalignment requiring high precision. In order to prevent this, it is most ideal to manufacture and test a test fixture with a composite material on which the actual payload is mounted, but the target composite material is also the same high-precision dimensional stability structure as the optical payload structure, which requires high cost.

This problem can be solved through a design that cancels the heat deformation because it is caused by the heat deformation on the plane in which the payload is mounted.

In the case of a thermal cycle test that simulates an orbital environment for space certification, deformations of tens to hundreds of micrometers will occur if the size of the subject is considered to be within the certification test temperature range of 70 ° C. This may not be a problem for general structures, but can cause serious problems for high-dimension stable structures such as optical structures.

In order to solve such a problem, in the test fixture according to the present invention, a fixed boundary condition is given to a position where a test object is mounted, and in the shape design, connecting beams extending horizontally from the mounting positions of the test object to each other are connected to each other. A flexure (flexible that can be easily deflected and restored) was provided to offset the planar deformation.

Based on the mounting position, the deformation of the test fixture is designed to offset at the appropriate site, so that the subject of the present invention that the thermal deformation is not applied to the actual test object is as follows.

According to one embodiment of the jig for thermally testing a test object according to the present invention, the heat-period test jig includes a mounting portion for mounting the test object, and a beam extending horizontally in the form of a cantilever in one or two directions from each mounting portion. And an end portion of the mounting portion side of each cantilever beam is fixed to prevent positional movement, and the cantilever beam from each mounting portion is connected to the cantilever beam from another mounting portion by a flexure member, thereby allowing the cantilever beam to respond to temperature changes. The length change in the longitudinal direction of is received by the flexure member.

According to a preferred embodiment of the present invention, the flexure member may consist of a plate-like member connecting the cantilever beam, and accommodates the change in the length of the cantilever beam by the bending deformation of the plate-like member. Such a flexure member is preferably installed at the center of the distance between the mounting portions to offset the deformation in the plane.

According to a preferred embodiment of the present invention, the cantilever beams each have a protrusion partially protruding in the cross section of the end portion, and the flexure member may be configured to connect the protrusions of the cantilever beams.

According to a preferred embodiment of the present invention, two cantilever beams connected to the flexure member are spaced apart from each other and point in a parallel direction, and the flexure member is attached to an end cross section perpendicular to the longitudinal direction of the cantilever beam and extends by a separation distance. Can be connected to the cantilever beam.

According to a preferred embodiment of the present invention, the cantilever beams and the flexure members may form a polygonal loop-shaped heat cycle testing jig having three or more mounting portions. This thermal cycle test fixture is particularly suitable for supporting by testing the ends of the truss structure.

The test subject may also include a support on which the high-dimension stable component is mounted and two or more trusses attached to the support, wherein the cantilever beams are provided when some compartment of the support is parallel to the plane formed by the cantilever beams. The flexure members form an open loop and may place some compartments of the test object in the open portion of the loop.

The cantilever beam and the flexure member constituting the heat cycle test jig according to the present invention may both be made of metal.

According to a preferred embodiment of the present invention, the cantilever beams can be made only in an arrangement relationship parallel or orthogonal to each other. In addition, the flexure member connecting the two cantilever beams is preferably such that its longitudinal direction is disposed perpendicular to the longitudinal direction of the cantilever beam.

The flexure member may be connected and fixed to the end cross section of the cantilever beam or to the protrusion by fastening means such as screws.

A stator in contact with the bottom of the test environment can be attached to a position below the cantilever beam corresponding to the mounting portion of the heat cycle testing jig according to the present invention, and a fixed boundary condition can be imparted. If necessary, the heat-period test fixture may be moved or settled in a predetermined position.

According to the present invention, in the heat cycle test for space certification of a structure mounted on a satellite, the deformation of the test fixture is designed to be offset at an appropriate site based on the mounting position of the structure, which is a test object. This is not applied.

In addition, the heat cycle test fixture according to the present invention cancels the planar thermal deformation regardless of the material, it is not necessary to use an expensive composite material.

In particular, by conducting a heat cycle test using the jig according to the present invention, it is possible to obtain a reliable test result by allowing the test subject to maintain high-dimensional stability.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described with reference to drawings. It is to be understood that the embodiments shown in the figures are merely exemplary and are not intended to limit the invention.

1 (a) and (b) are schematic diagrams for explaining the concept of the flexure of the heat cycle jig according to the present invention.

Payloads such as satellite optical structures and ultra-precision antennas are mounted on the main structure via a support such as a bezel, and a truss is attached to the support so that the end of the truss is also mounted on the main structure. Thus, in order to simulate the state by connecting a part of the structure including the support and the truss to the main structure, a heat cycle test is performed by replacing a part corresponding to the main structure made of a composite material with a jig made of a material such as metal. In this case, thermal expansion or thermal contraction occurs in the jig according to the temperature change during the heat cycle test, and the angle between the trusses and the support and the truss is changed, so that the evaluation of the payload requiring high-dimensional stability can be made accurately. There will be no.

Therefore, in the present invention, the thermal deformation of the jig during the heat cycle test does not cause deformation or stress in the mounting position, and thus the thermal deformation of the jig does not affect the structure to be tested. As shown in b), the mounting portions 14 of the jig on which the structure including the support and the truss are supported set a constraint boundary condition in which the positional change does not occur, and the beam 12 between the mounting portions 14 Is configured in a divided form and the flexure member 16 is interposed therebetween.

1 (a) and (b), however, for the purpose of briefly explaining the principles of the present invention, only two of the plurality of mounting portions 14 are shown, and the test object is heated by surface contact. It is firmly fixed to the test fixture 10, but for the sake of simplicity, only the portion corresponding to the center of the surface contact is marked with the symbol "+".

In the embodiment of FIG. 1A, the beam 10 is formed in a cantilevered form from a mounting portion 14 to which a fixed boundary condition is imparted, for example, by a stator (not shown) disposed below the beam 10. In addition, a predetermined gap is formed between the pair of beams 10 facing each other such that longitudinal deformation of the beams 10 by thermal expansion is possible.

As an example of an embodiment in which the flexure member 16 is arranged between opposing beams, the cross section of the beam 12 may be rectangular, for example, and a projection 13 is formed from an edge of the end face, and an opposing cantilever From the end face of the beam 12 a projection 13 is formed from the opposite edge, and the ends of the projections 13 of the two beams 12 are connected by the flexure member 16. At this time, the end face of the protrusion 13 is preferably flat, so that the flexure member 16 is easily disposed and attached, and the height of the protrusion 13 is the flexure member 16 with respect to the longitudinal direction of the beam 12. Is preferably set to face vertically.

By such a configuration, the flexure member 16 can more easily deflect or deform two cantilever-shaped beams 12 while flexing or bending deformation, and the flexure member 16 exhibiting such an action. The furnace does not require special materials and conventional plate metal can be used.

In addition, the flexure member 16 can be easily attached to the end of the projection 13 of the beam 12 by fasteners (not shown), for example, screws, bolts and the like.

In the embodiment of Fig. 1 (b), when there is a difference in the distance between the two mounting portions 14 in the x direction and the y direction with respect to an arbitrary plane xy coordinate system of the heat cycle testing jig, the beam 12 and the plane The structure regarding arrangement | positioning of the lexer member 16 'is shown. Of course, as shown in FIG. 1A, a pair of beams 12 may be disposed to be inclined with respect to the x and y directions so that the flexure member 16 may be disposed so that the cross sections of the beams 12 face each other. You will understand the point.

In the configuration illustrated in FIG. 1B, a pair of cantilever-shaped beams 12 from each mounting portion 14 are arranged in parallel and spaced apart from each other by a predetermined distance, and the flexure member 16 ' It is attached to the end face of 12 and extends by a separation distance to connect the two beams 12 to each other. The dotted line in the figure exaggerates the shape in which the cantilever-shaped beam 12 is thermally expanded and thus the flexure member 16 'is curved.

According to the configuration as shown in Fig. 1 (a) and (b), regardless of the material of the test jig, a relatively simple structure, the length change caused by the thermal expansion and thermal contraction of the beam which is the main structure of the heat cycle test jig Since it is absorbed and offset by the flexural deformation of the lexer member, the effect of thermal deformation on the target specimen is completely eliminated.

2A to 2C are plan views illustrating examples of some embodiments in which the heat cycle test jig 10 is configured by combining the flexure concept illustrated in FIG. 1. The flexure member shown in (a) or (b) of FIG. 1 is extended by extending the beam 16 in one or two directions from each mounting portion 14 of the heat cycle test fixture 10 to which the test object is attached. By being connected by (16, 16 '), the heat cycle testing jig 10 forms a closed loop or an open loop in its overall shape on a plan view.

The heat cycle test fixture 10 illustrated in FIG. 2A can be used to heat cycle test a test object supported by, for example, three trusses. This test jig 10 will be easily understood that the overall shape is triangular but may be configured in a rectangular or more complicated shape depending on the number of the mounting portions 14 supporting the test object.

The embodiment illustrated in FIG. 2 (b) is a heat cycle testing jig 10 for carrying out a heat cycle test by supporting four portions of a test subject. When a part of the test object is in contact with the plane formed by the mounting portions 14 of the heat cycle testing jig 10, as shown in the drawing, the two mounting portions which open part of the loop to contact the opening portion are shown. Both ends of the partial compartment of the test subject may be arranged to be supported.

2 (c) is a modified form of the heat cycle test jig 10 of (b), for supporting the test object at the same relative position as the mounting portions 14 of the jig 10 shown in (b) The heat cycle jig 10 is shown. In FIG. 2 (c), all the beams 12 are arranged to have orthogonal or parallel relations with each other, so that the flexure member 16 'as shown in FIG. 1 (b) is also employed. There is a difference from (b) of FIG.

As illustrated in FIG. 2C, in the predetermined plane xy coordinate system, when the longitudinal direction of all the beams 12 is disposed only in the x direction or the y direction, the jig 10 for thermal cycle test is constructed. In addition, it is easy to manufacture as compared to the heat cycle test jig 10 shown in FIG. 2 (b), and when the test object is changed, it is also easy to change the structure of the heat cycle test jig 10 accordingly. do.

3 is a perspective view schematically showing an embodiment in which the test object 20 is mounted on the heat cycle testing jig 10. In this embodiment, the test object 20 includes a bezel 22 serving as a support on which the optical structure and other components are mounted, and two trusses 24 fixed downward and fixed downward near the upper left and right sides of the bezel 22. It is a structure. A fastening aid is attached to the lower both ends of the bezel 22 and one end of the truss 24, and is firmly fixed to the mounting portion of the heat cycle test fixture 10 by a fastener such as a bolt (not shown). Since the structure of the bezel 22 and the arrangement of the components mounted on the bezel are not related to the essential features of the heat-period test jig 10 according to the present invention, a detailed description of the bezel and the mounting components will be omitted. .

The heat cycle test fixture 10 illustrated in FIG. 3 is rectangular in cross section, and is made of aluminum in this embodiment as an example. The cantilever-shaped beams 12 extending from the mounting portion 14 are connected to each other in combination with the flexure members 16 and 16 ', and the flexure members are fastened to the surface or the projection of the end of the beam by a fastener such as a bolt. 17) is firmly fixed. In addition, the stator 18 is attached to the lower side of the beam 14 at the position corresponding to the mounting portion 14 so that the constraint boundary condition at the mounting portion 14 can be set.

According to the configuration as shown in FIG. 3, among the beams 12 between the bezel 22 and the truss 24, the cantilever-shaped beam 12 from the bezel 24 side is formed by the lower stator 18. The heat deformation in the truss direction by the constraint boundary condition, and the cantilever-shaped beam 12 from the truss 24 side is heat deformation in the bezel direction by the constraint boundary condition by another stator 18 below. Thus, the flexure member 16 'in the center absorbs all the heat deformations to cancel out the heat deformations in the truss / bezel direction. Similarly, the flexure member 16 disposed between the trusses 24 absorbs and offsets the heat deformation caused by the cantilever-shaped beam 12 on both sides.

4 is a bottom perspective view of the heat cycle testing jig 10 illustrated in FIG. 3. The lower surface of the beam 12 corresponding to the upper surface of the beam 12 to which the test object is mounted is fixed to the restraint boundary by attaching a height-adjustable stator 18 to be fixed to the floor in the equipment constituting the test environment. Allow conditions to form. Moreover, the rotor 19 is attached to the side of the stator 18, and enables the movement of the heat cycle testing jig 10 as necessary. Since the configuration of the stator 18 is known, detailed description thereof will be omitted.

According to the heat cycle test jig of the present invention based on the above-described embodiment, since the thermal deformation of the test jig is offset by the flexure member disposed between the mounting parts while the mounting part of the structure as the test object is fixed, the test object The thermal cycle test fixture is not affected by thermal deformation. Therefore, even if the composite material, which is the material of the actual satellite main structure, is not fabricated for the thermal cycle test fixture, the test object can maintain high-dimensional stability.

As mentioned above, although preferred embodiment of this invention was described, the scope of the present invention is not limited only to this embodiment, A various deformation | transformation is naturally possible without departing from the essential and essential structure of this invention. Accordingly, the foregoing embodiments in the present invention are merely exemplary and should not be construed as having a limiting meaning, the scope of the present invention including matters set forth in the appended claims and all modifications that may be understood therefrom. It should be understood that.

1 is a schematic view for explaining the concept of a flexure according to the present invention.

2 is a schematic plan view illustrating various embodiments of a heat cycle test fixture in accordance with the present invention.

3 is a schematic perspective view showing a state in which a test object is mounted on a heat cycle test jig according to the present invention;

4 is a schematic bottom perspective view of a jig for heat cycle test according to the present invention;

Description of the Related Art [0002]

10: jig for heat cycle test

12: beam

14: mounting part

16, 16 ': flexure member

17: Fastener

18: stator

19: rotating body

20: test subject

22: bezel

24: Truss

Claims (10)

In the heat cycle test jig used for the heat cycle test of the test subject, A plurality of beams having end portions spaced apart from each other and facing each other, the beams including protrusions formed at the end portions; A plurality of mounting portions formed in each of the plurality of beams; And And a flexure member that connects the protrusions and absorbs the longitudinal length change due to thermal deformation by bending deformation so as to prevent the change of the relative position of the mounting parts. delete The method of claim 1, The at least one pair of split beams are spaced apart from each other and point in parallel directions, And a flexure member is attached to the ends of the pair of parallel beams and extends by a separation distance to connect the beams. The method of claim 1, And the flexure member is a plate-shaped member arranged to face in a direction perpendicular to the longitudinal direction of the beam. The method of claim 1, Beams on both sides of the flexure member are heat cycle testing jig characterized in that the distance to the mounting portion is the same. The method of claim 1, The beams and the flexure members form an open loop, The opening part of the open loop jig for a thermal cycle test, characterized in that some compartments of the test subject is disposed. The method of claim 1, Jig for heat cycle testing, characterized in that the beams are arranged in parallel or perpendicular directions to one another. The method of claim 1, The jig for thermal cycle testing, characterized in that the beam and the flexure member are made of metal. The method of claim 1, The test object is a jig for a thermal cycle test, characterized in that it comprises a support on which the satellite payload is mounted, and two or more trusses fixed to the support. The method of claim 1, A jig for heat cycle testing, characterized in that a stator is attached below the beam at the mounting position.

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