Normal-temperature dead-holding focusing and locking device

Abstract

The application provides a normal-temperature locking device for focusing, which comprises a double-path SMA clamp, a mounting and positioning element, a thin-film electric heater and a temperature sensor; the double-path SMA clamp is sleeved on the output shaft of a focusing motor and is fixedly connected with the mounting and positioning element beside the output shaft of the focusing motor; the mounting and positioning element is mounted on other fixed structures of a remote sensor through a self-mounting interface and limits the movement of the double-path SMA clamp; the thin-film electric heater and the temperature sensor are arranged on the mounting and positioning element and are connected with a temperature controller of the remote sensor; the temperature controller of the remote sensor controls the on-off of the thin-film electric heater based on the temperature of the mounting and positioning element transmitted by the temperature sensor and a preset temperature control threshold value of temperature rise, so as to implement the holding and releasing of the output shaft of the focusing motor. The device can keep the holding state for a long time at normal temperature, does not need to be powered or specially treated, realizes the locking and releasing through the phase change deformation of SMA material, and can realize the long-term reliable locking by using the device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of space optical remote sensors, and particularly relates to a normal-temperature dead-hold focusing locking device. BACKGROUND

[0002] The focusing mechanism is an important component of a space optical remote sensor, and its main function is to adjust the position of an optical element or the position of a focal plane of the remote sensor, so as to compensate for optical misalignment caused by structural deformation or object distance change caused by changes in a target scene. The mechanism is a typical on-orbit moving component, and is required to have locking, releasing and precise movement functions, and needs to withstand the harsh mechanical environment of the launch phase and the vacuum radiation environment in orbit. In actual application, the actual on-orbit working time of the focusing mechanism is much shorter than the on-orbit time of the camera, and the focusing mechanism only works when focusing is needed, and the on-orbit working time of the normal camera focusing mechanism is usually less than 200 times, and each working time is less than 1 min, and the rest of the time only needs to provide position holding, that is, in a locked state.

[0003] Generally, the focusing mechanism of the remote sensor is locked by using a motor plus an electric lock, which needs to use the focusing motor to be powered on to realize the focusing lock. In actual application, the power-on locking is usually performed only in two states with relatively large vibration, such as ground mechanical test and launch phase, and the focusing motor is required to withstand the mechanical environment of the launch phase in the power-on state. For example, in actual application, the power-on locking is usually required to be performed 2 hours before launch, and the locking state is maintained until the in-orbit attitude is stable. For other states with relatively small vibration, such as ground transportation and ground assembly and test, it is not convenient / suitable to power on for a long time, so the focal plane locking can only be abandoned, and the focusing mechanism is kept in a released state. For this power-on locking scheme, since the focusing motor cannot be kept in the power-on locking state for a long time, and a large amount of heat is generated during locking, the locking time is limited.

[0004] Therefore, it is necessary to provide a remote sensor focusing mechanism locking device, which does not use the focusing motor to be powered on to realize the locking, and solves the problem that the remote sensor focusing mechanism cannot be kept in the locking state for a long time. SUMMARY

[0005] In order to overcome the deficiencies in the prior art, the present application provides a normal-temperature dead-hold and temperature-rising release focusing locking device, which can be kept in a dead-hold state for a long time at normal temperature, does not need to be powered on or specially treated, is only heated when focusing is needed, is released and locked, and realizes the purpose of long-term reliable locking. While meeting the locking and releasing functions, the technical problem that the remote sensor focusing mechanism cannot be kept in the locking state for a long time is solved.

[0006] The technical scheme provided by the present application is as follows:

[0007] The first aspect is a normal-temperature clamping focusing locking device, comprising a double-path SMA clamp, a mounting and positioning element, a heating element and a temperature sensor.

[0008] The double-path SMA clamp is sleeved on the focusing motor output shaft and fixedly connected with the mounting and positioning element beside the focusing motor output shaft.

[0009] The mounting and positioning element is mounted on other fixed structures of the remote sensor through a mounting interface thereof and limits the movement of the double-path SMA clamp.

[0010] The heating element and the temperature sensor are arranged on the mounting and positioning element and connected with a temperature controller of the remote sensor, the temperature controller controls the on-off of the heating element based on the temperature of the mounting and positioning element transmitted by the temperature sensor and a preset temperature control threshold value, starts and stops heating of the mounting and positioning element, and exchanges heat between the mounting and positioning element and the double-path SMA clamp; when focusing is not needed, the double-path SMA clamp is in a normal-temperature state, provides stable and reliable clamping force, and prevents the focusing motor output shaft from rotating; before focusing is needed, the heating element is powered on, heating is started, and when the temperature meets the temperature control threshold value, the double-path SMA clamp is fully deformed and elongated, releases the focusing motor output shaft, and the focusing motor output shaft is operated to perform a focusing action; after the focusing operation is completed, the heating element is powered off, the device is naturally cooled, and when the temperature is lower than M f , the double-path SMA clamp is contracted, re-clamps the focusing motor output shaft, and is locked, wherein M f is a phase change temperature in the cooling process.

[0011] Further, the double-path SMA clamp comprises a clamping / release annular segment and two end plate connecting segments, an inner profile surface of the clamping / release annular segment matches an outer profile surface of the focusing motor output shaft, is a clamping / release functional segment, the two end plate connecting segments are extension segments at two ends of the clamping / release annular segment, the extension segments at the two ends are superimposed, are fixedly connected with the mounting and positioning element beside the focusing motor output shaft through threaded fasteners penetrating through waist holes in the extension segments, and adjust the clamping force by adjusting the positions of the threaded fasteners in the waist holes.

[0012] Further, the positive pressure generated by the double-path SMA clamp when clamping the focusing motor output shaft is a clamping force F 抱紧 , the focusing drive load mass is m 负载 , and F 抱紧 ≥ 50×m 负载 ×g.

[0013] Further, a plurality of same-interval strip-shaped notches are processed on the clamping / release annular segment of the double-path SMA clamp close to the two end plate connecting segments, the strip-shaped notches extend to outer ends of the two end plate connecting segments, and the two end plate connecting segments are divided into a plurality of independent structural segments.

[0014] Further, the temperature rising control threshold of the double-way SMA clamp is A f +(10±2)℃, A f is the phase transition temperature of the double-way SMA clamp in the temperature rising process.

[0015] Further, the double-way SMA clamp is a double-way Ti-Ni based SMA clamp.

[0016] Further, the mounting and positioning element has a U-shaped interface or is a U-shaped piece, and the opening side of the U-shaped interface or the U-shaped piece accommodates the two end plate connecting segments, thereby implementing the butt joint of the double-way SMA clamp and the mounting and positioning element.

[0017] Further, the mounting and positioning element is made of metal, preferably made of 2A12O aluminum alloy, and O represents the annealed state of the 2A12 aluminum alloy.

[0018] Further, when the double-way SMA clamp and the mounting and positioning element are fixedly mounted, the contact surfaces of the two are smeared with heat-conducting silicone grease.

[0019] Further, the heating element and the temperature sensor are pasted on the mounting and positioning element by using heat-conducting silicone.

[0020] Further, the heating element is a thin film electric heater.

[0021] In the second aspect, a normal temperature dead-hold focusing locking method is implemented by using the normal temperature dead-hold focusing locking device in the first aspect, and includes the following steps:

[0022] The double-way SMA clamp is sleeved on the focusing motor output shaft and fixedly connected with the mounting and positioning element, and the heating element is controlled to be turned on or turned off by the remote sensor temperature controller based on the temperature of the mounting and positioning element transmitted by the temperature sensor and the temperature rising control threshold.

[0023] When focusing is not needed, the double-way SMA clamp is in a normal temperature state, thereby providing stable and reliable holding force and ensuring that the focusing motor output shaft cannot rotate; before focusing is needed, the heating element is powered on to start heating, when the temperature meets the temperature rising control threshold requirement, the double-way SMA clamp is fully deformed and elongated to release the focusing motor output shaft, the focusing motor output shaft is operated to perform a focusing action; after the focusing operation is completed, the heating element is powered off, the device is naturally cooled and cooled down, and when the temperature is lower than M f , the double-way SMA clamp is contracted to re-hold the focusing motor output shaft, thereby realizing locking.

[0024] The normal temperature dead-hold focusing locking device and the locking method provided by the present application have the following beneficial effects:

[0025] (1) The application utilizes a double-path SMA material to design and process a temperature rising deformation part, utilizes the principle of double-path SMA temperature rising deformation and temperature falling recovery, realizes normal temperature locking, temperature rising release and temperature falling locking. The double-path SMA clamp deformation is stable and controllable, has high reliability, has a larger design space, and meets different remote sensor requirements;

[0026] (2) The double-path SMA clamp can realize locking of a focusing driving shaft, and can be fixed on other non-moving structures of a remote sensor through reliable connection with a mounting positioning element, and keep its own position stable;

[0027] (3) The mounting positioning element is formed by using 2A12 O-state aluminum alloy material with high thermal conductivity. Thermal conductive silicon grease is smeared on the contact surface of the double-path SMA clamp and the positioning element, and is tightly connected, so that heat can be conducted to the double-path SMA clamp;

[0028] (4) The normal temperature locking focusing locking device is small in size and flexible in installation;

[0029] (5) The normal temperature locking focusing locking device has a normal temperature locking, temperature rising release and focusing locking scheme, and solves the problem that a remote sensor focusing mechanism cannot be reliably locked for a long time when not working. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A normal temperature locking focusing locking device structure connection schematic diagram is provided for the application;

[0031] Figure 2 A normal temperature locking focusing locking device structure exploded view is provided for the application.

[0032] REFERENCE SIGNS

[0033] 1 - focusing motor output shaft; 2 - double-path SMA clamp; 21 - locking / release ring-shaped section; 22 - two-end flat plate connecting section; 23 - waist hole; 24 - strip-shaped notch; 3 - mounting positioning element; 4 - heating element; 5 - temperature sensor; 6 - threaded fastener. DETAILED DESCRIPTION

[0034] The characteristics and advantages of the application will become clearer and more explicit with the following detailed description of the application.

[0035] The special word "exemplary" here means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here is not necessarily interpreted as superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0036] The application provides a normal temperature locking focusing locking device, as shown inFigure 1 and Figure 2 As shown in the figure, it comprises a double-way SMA (Shape Memory Alloys) clamp 2, a mounting positioning element 3, a heating element 4, a temperature sensor 5 and threaded fasteners (6 and 7).

[0037] The focusing motor output shaft 1 is the target part to be gripped / released by the double-way SMA clamp 2, which is sleeved on the focusing motor output shaft 1 and comprises a gripping / releasing annular section 21 and two end plate connecting sections 22. The inner profile of the gripping / releasing annular section 21 matches the outer profile of the focusing motor output shaft 1, which is a gripping / releasing functional section. The two end plate connecting sections 22 are extension sections at the two ends of the gripping / releasing annular section 21. The extension sections at the two ends are superimposed and fixedly connected with the mounting positioning element 3 beside the focusing motor output shaft 1 through threaded fasteners (6 and 7) passing through the waist holes 23 in the extension sections, and the gripping force is adjusted by adjusting the positions of the threaded fasteners (6 and 7) in the waist holes 23. If the positive pressure generated when the double-way SMA clamp 2 is gripped is F 抱紧 , the focusing drive load mass is m 负载 , then the required gripping force F 抱紧 ≥ 50 × m 负载 × g, g is the gravitational constant.

[0038] A plurality of, for example, 2-3, same-interval strip-shaped notches 24 are processed on the part of the gripping / releasing annular section 21 of the double-way SMA clamp 2 close to the two end plate connecting sections 22. The strip-shaped notches 24 extend to the outer ends of the two end plate connecting sections 22, dividing the two end plate connecting sections 22 into a plurality of independent structural sections. The strip-shaped notches reduce the difficulty of deformation of the double-way SMA clamp and facilitate faster response deformation of the double-way SMA clamp.

[0039] The double-way SMA clamp 2 is trained and tested before use to ensure that it is elongated when the temperature exceeds A f during the heating process, and the diameter after elongation is greater than the diameter of the focusing motor output shaft; it is contracted when the temperature is lower than M f during the cooling process, and the size after contraction is consistent with the normal temperature state, wherein A f is the phase transition temperature during the heating process, and M f is the phase transition temperature during the cooling process.

[0040] The installation positioning element 3, such as 2A12O aluminum alloy (O represents the annealing state of 2A12 aluminum alloy), is installed on other fixed structures of the remote sensor through a self installation interface, thereby avoiding the movement of the relative position of the double-path SMA clamp 2. Preferably, the installation positioning element 3 has a U-shaped interface or is a U-shaped piece, and the opening side of the U-shaped interface or the U-shaped piece accommodates the two end plate connecting segments 22, so as to realize the butt joint of the double-path SMA clamp 2 and the installation positioning element 3. Further, a plurality of threaded fasteners (6 and 7) are installed on the opening side of the installation positioning element 3, so as to realize the reinforcement of the connection.

[0041] When the double-path SMA clamp 2 is fixedly installed on the installation positioning element 3, the contact surfaces of the two are coated with heat-conducting silicone grease, so as to improve the heat transfer efficiency.

[0042] The heating element 4 and the temperature sensor 5 are pasted on the installation positioning element 3 by using heat-conducting silicone, and are connected with a remote sensor temperature controller. The remote sensor temperature controller controls the on-off of the heating element 4 based on the temperature of the installation positioning element 3 (equivalent to the temperature of the double-path SMA clamp 2) transmitted by the temperature sensor 5 and a temperature rise control threshold. In order to facilitate installation, the heating element 4 is preferably a thin film electric heater, which can be connected in series by using 2-3 pieces, and the heating temperature of the thin film electric heater is controlled by adjusting the power supply current.

[0043] When focusing is not required, the double-path SMA clamp 2 is in a normal temperature state, and a stable and reliable holding force is provided, so as to ensure that the focusing motor output shaft 1 does not rotate. Before focusing is required, the heating element 4 is powered on, heating is started, and the temperature rise control threshold is set to A f +(10±2)℃. When the temperature meets the threshold requirement, the double-path SMA clamp 2 is fully deformed and elongated, the focusing motor output shaft 1 is released, and the focusing motor output shaft 1 can perform a focusing action. After the focusing operation is completed, the heating element 4 is powered off, and the device is naturally cooled and cooled. When the temperature is lower than M f , the double-path SMA clamp 2 shrinks and reholds the focusing motor output shaft 1, so as to realize locking.

[0044] The application also provides a normal temperature holding and focusing locking method, which adopts the normal temperature holding and focusing locking device, sleeves the double-path SMA clamp 2 on the focusing motor output shaft 1, and fixedly connects the double-path SMA clamp 2 with the installation positioning element 3. The on-off of the heating element 4 is controlled by the remote sensor temperature controller based on the temperature of the installation positioning element 3 transmitted by the temperature sensor 5 and a temperature rise control threshold.

[0045] When focusing is not required, the double-path SMA clamp 2 is in a normal temperature state, and a stable and reliable holding force is provided, so as to ensure that the focusing motor output shaft 1 does not rotate. Before focusing is required, the heating element 4 is powered on, heating is started, and the temperature rise control threshold is set to A f+2)℃, when the temperature meets the threshold requirement, the double-way SMA clamping hoop 2 fully deforms and elongates, releasing the focusing motor output shaft 1, and the focusing motor output shaft 1 operates to perform the focusing action; after the focusing operation is completed, the heating element 4 is powered off, the device is naturally cooled, and when the temperature is lower than M f , the double-way SMA clamping hoop 2 contracts, re-clamps the focusing motor output shaft 1, and is locked.

[0046] The present application is described in detail above in combination with the specific embodiments and exemplary examples, but these descriptions cannot be understood as limiting the present application. It is understood by those skilled in the art that the technical solutions and embodiments of the present application can be variously replaced, modified or improved without departing from the spirit and scope of the present application, and these all fall within the scope of the present application. The protection scope of the present application is subject to the appended claims.

[0047] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

Claims

1. A normal temperature focus locking device, characterized in that, The device comprises a double-way SMA clamp (2), a mounting positioning element (3), a heating element (4) and a temperature sensor (5). The double-way SMA clamp (2) is sleeved on the focusing motor output shaft (1) and fixedly connected with the mounting positioning element (3) beside the focusing motor output shaft (1). The mounting positioning element (3) is mounted on other fixed structures of the remote sensor through a self-mounting interface, and the movement of the double-way SMA clamp (2) is limited. The heating element (4) and the temperature sensor (5) are arranged on the mounting positioning element (3) and connected with the remote sensor temperature controller, the remote sensor temperature controller controls the on-off of the heating element (4) based on the temperature of the mounting positioning element (3) transmitted by the temperature sensor (5) and the preset temperature control threshold value, starts and stops the heating of the mounting positioning element (3), and the mounting positioning element (3) exchanges heat with the double-way SMA clamp (2); when focusing is not needed, the double-way SMA clamp (2) is in a normal temperature state, a stable and reliable holding force is provided, and the focusing motor output shaft (1) cannot rotate; before focusing is needed, the heating element (4) is powered on, the heating is started, when the temperature meets the temperature control threshold value, the double-way SMA clamp (2) is fully deformed and elongated, the focusing motor output shaft (1) is released, the focusing motor output shaft (1) rotates to perform the focusing action; after the focusing operation is completed, the heating element (4) is powered off, the device is naturally cooled, when the temperature is lower than M f , the double-way SMA clamp (2) is contracted, the focusing motor output shaft (1) is held again, and locking is realized, wherein M f is a phase change temperature in the cooling process.

2. The normal temperature clamp focusing locking device according to claim 1, characterized in that, The double-way SMA clamp comprises a clamping / release annular section (21) and two end plate connecting sections (22), the inner profile of the clamping / release annular section (21) matches the outer profile of the focusing motor output shaft (1), and the two end plate connecting sections (22) are extension sections at the two ends of the clamping / release annular section (21), the extension sections at the two ends are superimposed, fixedly connected with the mounting positioning element (3) beside the focusing motor output shaft (1) through threaded fasteners penetrating the waist holes (23) in the extension sections, and the clamping force is adjusted by adjusting the positions of the threaded fasteners in the waist holes (23).

3. The normal temperature clamp focusing locking device according to claim 1, characterized in that, The positive pressure generated when the double-way SMA clamping hoop clamps the output shaft (1) of the focusing motor is the clamping force F 抱紧 The focusing drive load mass is m 负载 The clamping force F 抱紧 ≥ 50×m 负载 ×g, g is the gravitational constant.

4. The normal temperature clamp focusing locking device according to claim 1, characterized in that, A plurality of same-interval strip-shaped notches (24) are formed on the part of the clamping / release annular section (21) of the double-way SMA clamp (2) close to the two end plate connecting sections (22), the strip-shaped notches (24) extend to the outer ends of the two end plate connecting sections (22), and the two end plate connecting sections (22) are divided into a plurality of independent structural sections.

5. The normal temperature clamp focusing locking device according to claim 1, wherein, The temperature increase control threshold of the double-way SMA clamping hoop (2) is A f + (10±2)℃, A f is the phase transition temperature of the double-way SMA clamping hoop during temperature increase.

6. The normal temperature clamp focusing locking device according to claim 1, wherein The double-way SMA clamp (2) is a double-way Ti-Ni-based SMA clamp.

7. The normal temperature clamp focusing locking device according to claim 1, wherein The mounting positioning element (3) has a U-shaped interface or is a U-shaped piece, and the opening side of the U-shaped interface or the U-shaped piece accommodates the two end plate connecting sections (22) to implement the butt joint of the double-way SMA clamp (2) and the mounting positioning element (3).

8. The normal temperature clamp focusing locking device according to claim 1, wherein, The mounting positioning element (3) is made of metal.

9. The normal temperature clamp focusing locking device according to claim 1, wherein, When the double-way SMA clamp (2) and the mounting positioning element (3) are fixedly mounted, the contact surfaces of the two are smeared with heat-conducting silicone grease; and / or The heating element (4) and the temperature sensor (5) are adhered to the mounting positioning element (3) by heat-conducting silicone; and / or The heating element is a thin-film electric heater.

10. A normal temperature focus locking method, characterized in that, The device is implemented by using the normal-temperature clamping focusing locking device of any one of claims 1 to 9, and comprises the following steps: The double-way SMA clamp (2) is sleeved on the focusing motor output shaft (1) and fixedly connected with the mounting positioning element (3), and the on-off of the heating element (4) is controlled by the temperature sensor (5) based on the temperature of the mounting positioning element (3) and the temperature control threshold value transmitted by the temperature sensor (5) by using the temperature controller of the remote sensor. When there is no need for focusing, the double-way SMA clamping hoop (2) is in normal temperature state, providing stable and reliable clamping force to ensure that the focusing motor output shaft (1) will not rotate; before focusing is needed, the heating element (4) is powered on to start heating, and when the temperature meets the temperature control threshold requirement, the double-way SMA clamping hoop (2) fully deforms and elongates to release the focusing motor output shaft (1), and the focusing motor output shaft (1) operates to perform focusing action; after the focusing operation is completed, the heating element (4) is powered off, and the device naturally cools down, and when the temperature is lower than M f , the double-way SMA clamping hoop (2) contracts to re-clamp the focusing motor output shaft (1), achieving locking, wherein M f is the phase transition temperature during cooling.

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