A high-precision force measuring mechanism for a flexible lever weight support

Abstract

The application relates to a high-precision force measuring mechanism for flexible lever weight support, comprising a first mounting base, a first fixed plate, a second mounting base, a second fixed plate, a positioning structure and a sensor tool, wherein the first mounting base and the second mounting base are both right-angled trapezoidal structures, the rectangular end faces of the first mounting base and the second mounting base are oppositely spaced in the height direction and are connected and fixed through the first fixed plate and the second fixed plate; the positioning structure is used for realizing coarse positioning and fine positioning of a flexible lever weight support assembly to be measured; the sensor tool is installed on the rectangular end face of the first mounting base and is used for positioning the force zero point of the flexible lever weight support assembly and measuring the support force; the application uses multiple positioning modes to accurately determine the working direction of the flexible lever weight support, and the force measuring precision is improved.

Description

Technical Field

[0001] This invention belongs to the field of high-precision flexible support technology, and specifically relates to a high-precision force measuring mechanism for flexible lever hammer support. Background Technology

[0002] High-quality optical imaging relies heavily on the high-precision surface shape of optical mirrors. In the field of optical imaging, multiple factors influence the surface shape accuracy of mirrors, such as optical processing, optical coating, environmental temperature changes, and optical support. Among these, optical support is the most difficult variable to control precisely, and its quality directly affects the surface shape accuracy of the mirror. Flexible supports are often used to compensate for optical misalignment caused by factors such as the precision of mechanical processing, mechanical assembly, optical adjustment, and temperature changes. This avoids the hard impacts that rigid supports can cause to optical components. Furthermore, flexible supports also have a certain buffering and vibration-absorbing effect, greatly protecting the impact resistance of brittle optical components.

[0003] There are various forms of flexible support for optical mirrors, such as bipod flexible support, mechanical floating support (Whiffle tree), lever-weight support, mercury belt support, and flexible steel belt side support. For the flexible lever-weight support structure, it is mainly composed of flexible connecting rod, lead weight, weight connecting rod, rotating pin, support base, and connecting ball head. The weight of the weight itself is used to balance the gravity of the optical element or part of the gravity. The flexible connecting rod is mainly used to unload the thermal stress caused by the mismatch of the thermal expansion coefficients of the optical element and the mechanical metal element when the temperature changes. At the same time, it also has a certain unloading effect on the stress caused by processing and assembly errors. This structure has high stiffness in its normal working direction, which is the main direction for providing support force. In addition, it has high optical surface accuracy, which is a nanoscale variation. Therefore, it is also quite sensitive to the support force and has high requirements for the accuracy of the support force. However, the support force provided by the weight with flexible structure is difficult to measure accurately. During the assembly and adjustment stage, when measuring the support force, the eccentricity and angular deviation of the flexible link will cause elastic deformation of the flexible link in the non-working direction, resulting in inaccurate force measurement. This makes it difficult to match the support force provided by the weight with the theoretical value during the assembly and adjustment stage.

[0004] Traditional lever-weighted supports do not have flexible structures; the lever linkage is a rigid structure, which is easy to level and relatively easy to measure force. There are few reports on force measurement schemes for lever-weighted supports with flexible structures. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a high-precision force measuring mechanism for flexible lever hammer support. The mechanism is fixed on a high-precision standard optical platform, and the reference of the flexible lever hammer support component to be tested is accurately located through various positioning methods. Relying on the mechanism's own stiffness and connection stiffness, the supporting force provided by the hammer is accurately measured.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-precision force measuring mechanism for supporting a flexible lever weight includes: an end face positioning block, a U-shaped positioning block, an L-shaped positioning block, a first mounting base, a second mounting base, a translation block, a translation set screw, a sensor mounting base, a force sensor, an adapter block, a force measuring block, a first fixing plate, and a second fixing plate.

[0008] Both the first and second mounting bases adopt a high-rigidity right-angled trapezoidal structure. They are installed at intervals relative to each other, and the central interval area is used to install and fix the flexible lever weight support assembly, positioning structure (L-shaped positioning block, end face positioning block, U-shaped positioning block), and sensor fixture (force measuring block, adapter block, force sensor, sensor mounting base) of the test.

[0009] The component under test is mounted on the second mounting base; the L-shaped positioning block, together with the end face positioning block and the U-shaped positioning block mounted on the first mounting base, accurately locates the working direction of the component under test; the force measuring block, the adapter block, the force sensor, and the sensor mounting base form a sensor fixture and are mounted in the vertical slide groove of the first mounting base through the sensor mounting base, moving up and down as a whole, and finding the zero point of force measurement through the force sensor reading. Finally, the first mounting base and the second mounting base are connected and fixed through the first fixing plate and the second fixing plate to improve the overall connection rigidity of the force measuring mechanism.

[0010] The second mounting base is fixed to a high-precision standard optical platform with screws. The flexible lever weight support assembly to be tested is fixedly connected to the mounting hole of the second mounting base through the support base. The bottom surface of the L-shaped positioning block is leveled with the bottom surfaces of the first and second mounting bases through the optical platform. The support base of the flexible lever weight support assembly to be tested is rotated at a small angle so that the side of the L-shaped positioning block is completely in contact with the side end face of the weight support base, thereby making the center of the flexible connecting rod of the flexible lever weight support assembly to be tested coincide with the vertical plane (XZ plane) of the first mounting base.

[0011] The first mounting base has a groove on its end face that can be fitted with the end face positioning block with clearance. The two are fixedly connected by screws. The first mounting base is moved so that the end face of the end face positioning block is slightly raised to the end face of the flexible connecting rod. The first mounting base is initially connected to the optical platform and the screws are pre-tightened.

[0012] The translation block is fixed to the optical platform. Translation screws are installed on both sides of the translation block. The translation screws are connected to the translation block by threads. The end face of the screw contacts the first mounting seat. By rotating the translation screw, the first mounting seat is moved forward, so that the end face positioning block is close to the end face of the flexible connecting rod of the flexible lever weight support assembly under test. The two end faces are tightly fitted without gaps. The first mounting seat is fixed to the optical platform with screws. At this time, the center of the flexible connecting rod of the flexible lever weight support assembly under test is roughly leveled with the vertical end face (YZ plane) of the first mounting seat.

[0013] The end face positioning block on the first mounting base has an open structure on the side of the horizontal slide groove. After the first mounting base is fixed, the end face positioning block can be pulled out from the horizontal slide groove of the first mounting base.

[0014] The sensor fixture mainly consists of a high-precision force sensor, a sensor mounting base, an adapter block, and a force measuring block. The sensor is mounted on the sensor mounting base, and the adapter block and the force measuring block are installed in sequence below the force sensor.

[0015] Furthermore, the sensor fixture can be installed in the vertical slide groove on the first mounting base via a force sensor, allowing the sensor fixture to move up and down to adjust the initial force measurement position.

[0016] Furthermore, the force measuring block has a ring structure, which can measure both tensile and compressive forces. The flexible lever weight support assembly to be measured is installed in the upper mounting hole of the second mounting base, and the sensor fixture is installed in the vertical slide groove below the first mounting base. This force measuring mechanism can be compatible with the measurement of push and pull forces.

[0017] Furthermore, the U-shaped positioning block is installed on the first mounting base through a stop, and the inner surface of the U-shaped positioning block is perpendicular to the bottom surface of the first mounting base through a dimensional chain transmitted by machining.

[0018] Further, adjust the weight connecting rod of the flexible lever weight support assembly to be tested (without the weight lead block installed) so that the flexible connecting rod linked by the rotating pin fits the inner surface of the U-shaped positioning block. At this time, the center of the flexible connecting rod is precisely leveled with the vertical end face (YZ plane) of the first mounting seat, and the direction of the lead weight of the flexible connecting rod, i.e. the working direction, is accurately found.

[0019] Further, at this point, adjust the sensor fixture up and down. When the force measuring block just contacts the ball joint of the hammer to be measured, and the reading of the high-precision force sensor is in the range of 0~0.1N, the zero point of force measurement is determined. Fix the sensor fixture and remove the U-shaped positioning block.

[0020] Furthermore, the first fixed plate and the second fixed plate above the connecting mechanism are connected to improve the connection rigidity of the mechanism. At this point, the installation of the force measuring mechanism is completed, and the entire force measuring mechanism is now in place.

[0021] Next, install the lead weight and move its position back and forth so that the force measured by the force sensor is within ±1N of the theoretical force. Then tighten the lead weight locking nut to end the force measurement.

[0022] The beneficial effects of this invention are as follows:

[0023] The high-precision force measuring mechanism for flexible lever hammer support of the present invention uses multiple positioning methods to accurately determine the working direction of the flexible lever hammer support; through the high rigidity of the tooling itself and the high rigidity of the connection between the components, the additional torque caused by the deformation of the flexible support in the non-working direction is further reduced, and the force measuring accuracy is improved, so that the force measuring accuracy can reach within ±1N. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the force measuring principle of a high-precision force measuring mechanism for a flexible lever weight support according to the present invention.

[0025] Figure 2 This is a front cross-sectional view of a high-precision force measuring mechanism for a flexible lever weight support according to the present invention.

[0026] Figure 3 This is a top view of a high-precision force measuring mechanism for a flexible lever weight support according to the present invention.

[0027] Figure 4 This is a side cross-sectional view of a high-precision force measuring mechanism for a flexible lever counterweight support according to the present invention.

[0028] Figure 5 This is an isometric view of a high-precision force measuring mechanism for a flexible lever weight support according to the present invention.

[0029] Figure label:

[0030] 1-Translation block; 2-First mounting base; 3-End face positioning block; 4-U-shaped positioning block; 5-Force measuring block; 6-Adapter block; 7-Force sensor; 8-Sensor mounting base; 9-First fixing plate; 10-Second mounting base; 11-L-shaped positioning block; 12-Under-test flexible lever weight support assembly; 12-1-Weight lead block; 12-2-Weight connecting rod; 12-3-Support base; 12-4-Rotating pin; 12-5-Flexible connecting rod; 12-6-Connecting ball head; 13-Translation set screw; 14-Second fixing plate. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] like Figure 1The diagram shows the force measurement principle of a high-precision force measuring mechanism for a flexible lever weight support according to the present invention. The force measuring mechanism precisely controls the supporting force provided by the flexible lever weight support assembly 12 (weight block 12-1, weight connecting rod 12-2, support seat 12-3, rotating pin 12-4, flexible connecting rod 12-5, connecting ball head 12-6) under test. When the center of the flexible link 12-5 of the flexible lever weight support assembly 12 coincides with the direction of the plumb bob, this is the working direction of the flexible link 12-5, which has high stiffness. At this time, the support force F1 provided by the connecting ball head 12-6 can be accurately measured. However, when the installation and positioning error causes the center of the flexible link 12-5 to not coincide with the direction of the plumb bob, the two orthogonal flexible springs of the flexible link 12-5 will undergo elastic deformation. At this time, the measured support force F2 is not only provided by the plumb bob, but also by the elastic torque generated by its elastic deformation in the non-working direction, which is superimposed on the support force, resulting in inaccurate force measurement. Therefore, the force measuring mechanism needs to accurately find the working direction of the flexible link 12-5.

[0033] like Figure 2 The diagram shows a front sectional view of a high-precision force measuring mechanism for a flexible lever weight support according to the present invention. It includes: a translation block 1, a first mounting base 2, an end face positioning block 3, a U-shaped positioning block 4, a force measuring block 5, a transition block 6, a force sensor 7, a sensor mounting base 8, a first fixing plate 9, a second mounting base 10, an L-shaped positioning block 11, a translation set screw 13, and a second fixing plate 14. The force measuring mechanism composed of the above components is mounted on a high-precision standard optical platform.

[0034] refer to Figure 3 , Figure 4 , Figure 5 Both the first mounting base 2 and the second mounting base 10 adopt a high-rigidity right-angled trapezoidal structure. Their rectangular end faces in the height direction are installed at intervals. The first mounting base 2 and the second mounting base 10 are connected and fixed by the first fixing plate 9 and the second fixing plate 14, improving the overall connection rigidity of the force measuring mechanism. The central interval area is used to install and fix the flexible lever weight support assembly 12 to be tested, the positioning structure (L-shaped positioning block 11, end face positioning block 3, U-shaped positioning block 4), and the sensor fixture (force measuring block 5, adapter block 6, force sensor 7, sensor mounting base 8). Specifically, the flexible lever weight support assembly 12 to be tested is installed on the mounting hole on the lower side of the second mounting base 10; the L-shaped positioning block 11 is installed in the working direction of the flexible lever weight support assembly 12 to be tested, which is jointly determined by the end face positioning block 3 and the U-shaped positioning block 4 installed on the first mounting base 2. The U-shaped positioning block 4 spans across both sides of the rectangular end face of the first mounting base 2; the rectangular end face of the first mounting base 2 includes a vertical groove and a horizontal groove, such as... Figure 5As shown, the end face positioning block 3 can slide freely in the horizontal slide groove of the first mounting base 2. Adjusting the front and rear positions of the first mounting base 2 makes the end face of the end face positioning block 3 slightly higher than the end face of the flexible connecting rod 12-5 of the flexible lever hammer support assembly 12 to be tested. The force measuring block 5, the adapter block 6, the force sensor 7, and the sensor mounting base 8 form a sensor fixture. The force sensor 7 is mounted on the sensor mounting base 8. The adapter block 6 and the force measuring block 5 are installed below the force sensor 7 in sequence. The force measuring block 5 can contact the flexible lever hammer support assembly 12 to be tested. The sensor mounting base 8 is installed in the vertical slide groove of the first mounting base 2, so that the force measuring sensor fixture can move up and down as a whole. The zero point of force measurement is found by reading the force sensor 7.

[0035] refer to Figure 4 The first mounting base 2 and the second mounting base 10 are fixed to the high-precision standard optical platform with screws. The support base 12-3 of the flexible lever weight support assembly 12 under test is fixedly connected to the mounting hole below the second mounting base 10. The bottom surface of the L-shaped positioning block 11 is completely leveled with the bottom surfaces of the first mounting base 2 and the second mounting base 10 through the optical platform surface. The support base 12-3 of the flexible lever weight support assembly 12 under test is rotated at a small angle so that the side of the L-shaped positioning block 11 is completely in contact with the side end face of the support base 12-3 of the flexible lever weight support assembly 12 under test, thereby making the center of the flexible connecting rod 12-5 coincide with the vertical surface (XZ surface) of the first mounting base 2.

[0036] refer to Figures 2-3 The translation block 1 is fixedly connected to the optical platform. Translation screws 13 are installed on both sides of the translation block 1. The translation screws 13 are connected to the translation block 1 by threads. The end face of the translation screw 13 contacts the first mounting seat 2. By rotating the translation screw 13, the first mounting seat 2 is pushed forward and translated, so that the end face positioning block 3 is close to the end face of the flexible connecting rod 12-5 of the flexible lever weight support assembly 12 under test. The two end faces are tightly fitted without gaps. At this time, the center of the flexible connecting rod 12-5 of the flexible lever weight support assembly 12 under test is roughly leveled with the vertical end face (YZ plane) of the first mounting seat.

[0037] Figure 5 The end face of the horizontal slide groove where the end face positioning block 3 of the first mounting base 2 is located is an open structure. After the first mounting base 2 is fixed, the end face positioning block 3 is pulled out from the horizontal slide groove of the first mounting base 2.

[0038] Furthermore, the sensor fixture is installed in the vertical slide groove of the first mounting base 2 through the sensor mounting base 8, so that the sensor fixture can move up and down as a whole to adjust the initial position of force measurement.

[0039] Furthermore, the force measuring block 5 has a ring structure, which can measure both tensile force and compressive force. The flexible lever weight support assembly 12 to be measured is installed in the upper mounting hole of the second mounting base 10, and the sensor fixture is installed in the vertical sliding groove below the first mounting base 2. This force measuring mechanism can be compatible with the measurement of push and pull forces, and can also be compatible with the force measurement of support assemblies with flexible connecting rods of different lengths. It can be used not only for lever weight supports with flexible structures, but also for lever weight supports without flexible mechanisms.

[0040] Furthermore, the U-shaped positioning block 4 is installed on the first mounting base 2 through a stop, and the inner surface of the U-shaped positioning block 4 is perpendicular to the bottom surface of the first mounting base 2 through a mechanical machining dimensional chain.

[0041] Further, adjust the weight connecting rod 12-2 of the flexible lever weight support assembly 12 under test (weight block 12-1 is not installed), so that the flexible connecting rod 12-5, which is linked by the rotating pin 12-4 of the flexible lever weight support assembly 12 under test, fits against the inner surface of the U-shaped positioning block 4. At this time, the center of the flexible connecting rod 12-5 is precisely leveled with the vertical end face (YZ plane) of the first mounting seat 2, and the plumb direction of the flexible connecting rod 12-5, i.e. the working direction, is accurately found.

[0042] Further, at this time, the sensor fixture is adjusted up and down. When the force measuring block 5 just contacts the ball head 12-6 of the hammer to be measured, and the reading of the high-precision force sensor 7 is in the range of 0~0.1N, the zero point of force measurement is determined, the sensor fixture is fixed, and the U-shaped positioning block 4 is removed.

[0043] like Figure 3 The first fixing plate 9 and the second fixing plate 14 above the connecting mechanism are connected to improve the connection rigidity of the mechanism. At this time, the force measuring mechanism is fully installed.

[0044] Next, install the lead weight 12-1 of the flexible lever support assembly 12 to be tested, move the position of the lead weight 12-1 back and forth so that the force measured by the high-precision force sensor 7 is within ±1N of the theoretical force, and tighten the locking nut of the lead weight 12-1 to end the force measurement.

[0045] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision force measuring mechanism for a flexible lever weight support, characterized in that, It includes a first mounting base, a first fixing plate, a second mounting base, a second fixing plate, a positioning structure, and a sensor fixture; The first mounting base and the second mounting base are both right-angled trapezoidal structures. The rectangular end faces of the first mounting base and the second mounting base are installed at intervals relative to each other in the height direction, and are connected and fixed by the first fixing plate and the second fixing plate. The positioning structure is used to achieve coarse and fine positioning of the flexible lever counterweight support assembly under test; it includes an L-shaped positioning block, an end face positioning block, and a U-shaped positioning block, wherein... The bottom surface of the L-shaped positioning block is level with the bottom surfaces of the first and second mounting seats, and its side surface is fully in contact with the side end face of the support seat of the flexible lever weight support assembly to be tested, which is used to locate the rotational degree of freedom of the flexible lever weight support assembly to be tested. The end face positioning block is located in the horizontal groove of the rectangular end face of the first mounting base, which is used to roughly determine the vertical direction of the flexible connecting rod in the flexible lever weight support assembly to be tested. The U-shaped positioning block spans the rectangular end face of the first mounting base and is used to accurately determine the vertical direction of the flexible connecting rod in the flexible lever weight support assembly to be tested. The sensor fixture is installed on the rectangular end face of the first mounting base and is used to locate the zero point of the force measurement of the flexible lever hammer support assembly and to measure the support force provided by the flexible lever hammer support assembly. The flexible lever hammer support assembly includes a hammer lead block, a hammer connecting rod, a support base, a rotating pin, a flexible connecting rod, and a connecting ball.

2. The high-precision force measuring mechanism for flexible lever counterweight support according to claim 1, characterized in that, The rectangular end face of the first mounting base includes a vertical slide groove and a horizontal slide groove.

3. A high-precision force measuring mechanism for a flexible lever weight support according to claim 2, characterized in that, The horizontal slide groove side of the rectangular end face of the first mounting base has an open structure, and the positioning block is pulled out from the horizontal slide groove after positioning; the U-shaped positioning block and the L-shaped positioning block are detachable.

4. A high-precision force measuring mechanism for supporting a flexible lever weight according to claim 1, characterized in that, The sensor fixture includes a force measuring block, a transition block, a force sensor, and a sensor mounting base. The force sensor is mounted on the sensor mounting base, and the transition block and the force measuring block are installed in sequence below the force sensor. The force measuring block can contact the flexible lever weight support assembly to be tested.

5. A high-precision force measuring mechanism for a flexible lever counterweight support according to claim 4, characterized in that, The sensor mounting base is installed in the vertical slide groove of the first mounting base, which allows the sensor fixture to move up and down as a whole. The zero point of force measurement is found by reading the force sensor and the supporting force provided by the flexible lever weight support assembly is measured.

6. A high-precision force measuring mechanism for supporting a flexible lever weight according to claim 1, characterized in that, The force measuring mechanism also includes a translation block and a translation set screw. The translation block is fixedly connected to the optical platform. Translation set screws are installed on both sides of the translation block. The end face of the translation set screw contacts the first mounting seat. By rotating the translation set screw, the first mounting seat is driven to translate forward, so that the end face positioning block is close to the end face of the flexible connecting rod of the flexible lever weight support assembly to be measured.

7. A high-precision force measuring mechanism for a flexible lever counterweight support according to claim 1, characterized in that, The force measuring mechanism is compatible with the measurement of push and pull forces, the force measurement of support components with flexible connecting rods of different lengths, and the support force measurement of lever-weighted support components without flexible mechanisms.

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