CN102889963A - Loading method of differential type horizontal micro-force loading device - Google Patents

Abstract

The invention discloses a loading method of a differential type horizontal micro-force loading device. The loading method of the differential type horizontal micro-force loading device is characterized in that a secondary lever which is arranged vertically serves as a center rod of the loading device, a pair of primary levers is symmetrically positioned on two sides of the secondary lever in the same vertical plane, and the primary levers are respectively connected with the secondary lever through two transitional rods which are respectively arranged on one sides of the primary levers. On the basis of a flexible hinge and lever principle, a secondary lever force reducing mechanism is built, and is used for generating small acting force; and by a flexible hinge, a friction link in a calibration system is omitted, and then the calibration accuracy is improved.

Description

Loading method of differential horizontal micro-force loading device

This application is a divisional application of the invention patent application with the filing date: 20110727, the application number: 2011102124700, and the invention title: differential horizontal micro-force loading device and loading method.

technical field

The invention relates to a loading method of a micro-force loading device applied in the technical field of measurement.

Background technique

With the vigorous development of modern science and technology, there are more and more occasions that require small force values, such as the study of mechanical properties of micro-scale components in micro-electromechanical systems, measurement of micro-friction phenomena, micro-force detection in micro-sensing and micro-robot assembly, etc. Therefore, the research, production, and production of micro force sensors will follow. But compared with its research and production, the performance measurement development of the micro force sensor itself appears to be relatively lagging behind. At present, the routinely used pulley weight method cannot be used for micro-force loading; there are Lorentz force and electrostatic force calibration methods, which cause instability due to many affected factors; in recent years, the application of micro-force using piezoelectric elements has become more and more More and more, but this method is costly, complicated to operate, and produces a small range of forces.

At present, the flexible hinge mechanism has been widely used in the fields of precision measurement and calibration, but there is still a lack of comprehensive consideration and research on the influence of the deformation of the flexible hinge, the position of the center of gravity of the lever, and the change of temperature on the accuracy of measurement and calibration. Structural design influenced by the two factors of temperature and temperature, and in order to obtain higher accuracy when calibrating or measuring the micro force, it is necessary to solve the influence of the above aspects on the calibration or measurement of the micro force, because gravity and temperature produce The impact may be far greater than the maximum range of micro-force loading, which will have a fatal impact on micro-force loading.

Contents of the invention

In order to avoid the shortcomings of the above-mentioned prior art, the present invention provides a loading method of a low-cost horizontal micro-force loading device that can meet the requirements of a certain precision force value, and is used for micro-force sensors, micro-electromechanical systems and various Calibrate a small force detector and provide support for force measurement systems with small force values.

The present invention solves technical problem and adopts following technical scheme:

The characteristics of the loading method of the differential horizontal micro-force loading device of the present invention are:

The differential horizontal micro-force loading device is set as follows: take the vertically arranged secondary lever as the central rod, and in the same vertical plane, a pair of primary levers are symmetrically located on both sides of the secondary lever, and pass through the The transition rod on each side is connected with the secondary lever.

The primary lever is an inverted "L"-shaped rod composed of a horizontal rod and a vertical rod. The loading weight is arranged at the rod end of the horizontal rod as the input end. The bottom end is connected to the outer end of the transition rod through a primary flexible hinge at the side of the rod, and the inner end of the transition rod is connected to the force point of the secondary lever through a secondary flexible hinge.

The bottom end of the secondary lever is set as a secondary fulcrum, the top of the secondary lever is a free end, a probe is set on the top of the secondary lever, and the probe is connected with the force sensor arranged on the micro-motion platform. touch.

A pair of connecting rods extending towards the side where the inner end of the transition rod is fixedly connected at the outer end of the transition rod, and a counterweight of the transition rod is fixedly connected at the rod end of the connecting rod, so that the center of gravity of the transition rod is adjusted to Where the secondary flexible hinge is located; at the horizontal rod end of the primary lever a primary lever counterweight is set so that the center of gravity of the primary lever is adjusted to the primary fulcrum position; at the secondary lever On the position between the secondary fulcrum and the secondary flexible hinge, the secondary lever counterweight is set through the fixed cantilever, so that the common center of gravity of the secondary lever, transition rod, connecting rod and transition rod counterweight is adjusted to the second level. level fulcrum position.

The loading method of the differential horizontal micro-force loading device is to realize differential loading in one of the following ways:

Method 1: Load the loading weights of the same mass at the two input ends, and the probe is at the initial position at this time; set the force sensor to keep at the initial position, change the mass difference of the loading weights at the two input ends, and when the force Obtain different loading forces on the sensor;

Method 2: Load the loading weights of the same mass at the two input ends. At this time, the probe is at the initial position, and then change the mass difference between the loading weights at the two input ends to make the probe offset, and the probe will be moved by the force sensor. Gradually move from the offset position to the initial position, the closer the force sensor is to the initial position, the greater the force of the probe on the force sensor, and finally the loading force is determined by the mass difference between the weights loaded at the two input ends and the displacement of the force sensor the size of.

The loading method of the differential horizontal micro-force loading device of the present invention is also characterized in that in the differential horizontal micro-force loading device, at the positions of the primary fulcrum and the secondary fulcrum, the primary lever and the secondary lever are respectively The fulcrum flexible hinges are arranged on the base, and the fulcrum flexible hinges are suspended on the machine base to be consistent with the direction of gravity.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

1. The present invention establishes a two-stage lever force reduction mechanism based on the principle of flexible hinges and levers, which is used to generate small forces. The application of flexible hinges reduces the friction links in the calibration system and improves the calibration accuracy.

2. The present invention utilizes the loading force of weights, which is simple, reliable, convenient to operate, and can perform dynamic loading within a certain range, and can be widely used in various occasions.

3. The present invention first adjusts the center of gravity of the transition rod to the position of the secondary flexible hinge by setting each counterweight, and then adjusts the common center of gravity of the secondary lever and the transition rod with the counterweight structure to the position of the secondary fulcrum Finally, the center of gravity of the first-level lever is adjusted to the position of the first-level fulcrum, which eliminates the influence of the change of the center of gravity on the rods, makes the generated micro-force more stable, and has strong anti-interference factors.

4. The present invention adopts a symmetrical mechanism, which eliminates the influence of temperature and improves the accuracy of force loading.

5. The flexible hinges of each fulcrum at the first-level fulcrum and the second-level fulcrum of the present invention are set in line with the direction of gravity, which eliminates the bending deformation and bending stress caused by gravity on the flexible hinge. Otherwise, the bending moment generated by gravity will cause Destruction of the flexible hinge.

Description of drawings

Fig. 1 is the schematic diagram of horizontal micro-force loading device in the present invention;

Fig. 2 is a schematic diagram of the counterweight structure on the transition rod of the present invention;

Labels in the figure: 1 secondary lever; 1a cantilever; 1b secondary lever counterweight; 2 transition rod; 2a connecting rod; 2b transition rod counterweight; 3a horizontal rod; 3b vertical rod; 4 loading weight; 5 Level 1 fulcrum; 6 Level 1 flexible hinge; 7 Level 2 flexible hinge; 8 Level 2 fulcrum; 9 Probe; 10 Micro-motion platform; 11 Force sensor; 12 Level 1 lever counterweight.

Detailed ways

Referring to Fig. 1 and Fig. 2, a pair of inverted "L" type primary levers, a secondary lever 1 and a pair of transition rods 2 composed of a horizontal bar 3a and a vertical bar 3b are included in this embodiment; The primary lever counterweight 12, a pair of transition lever counterweights 2b and the secondary lever counterweight 1b;

As shown in Figure 1, with the vertically arranged secondary lever 1 as the center rod, in the same vertical plane, a pair of primary levers are symmetrically located on both sides of the secondary lever 1, and pass through the transition on each side respectively. Rod 2 is connected with secondary lever 1;

The primary lever is an inverted "L"-shaped bar made of a horizontal bar 3a and a vertical bar 3b, and the loading weight 4 is arranged on the rod end of the horizontal bar 3a as the input end, and the loading weight 4 shown in Fig. 1 is hung on The primary load F1a is formed on the horizontal rod 3a, the primary fulcrum 5 is located in the middle of the horizontal rod 3a, and the primary fulcrum 5 is arranged on the base through a flexible hinge; the bottom end of the vertical rod 3b passes through a primary flexible hinge at the side of the rod The hinge 6 is connected to one end of the transition rod 2, and the other end of the transition rod 2 is connected to the force point of the secondary lever 1 through the secondary flexible hinge 7;

The bottom end of the secondary lever 1 is set as a secondary fulcrum 8, and the secondary fulcrum 8 is set on the base through an elliptical flexible hinge; the top of the secondary lever 1 is a free end, and a probe is set on the top of the secondary lever 1 9. Use the probe 9 to contact the force sensor 11 provided on the micro-motion platform 10 . In a specific implementation, the force sensor 11 is driven by the micro-motion platform 10 to move in the horizontal direction.

In order to eliminate the influence of temperature, two primary levers and two transition rods 2 are symmetrically distributed on both sides of the secondary lever 1 .

In order to eliminate the influence of the change of the center of gravity on the rods, counterweights can be set at the corresponding positions: a pair of connecting rods 2a extending toward the inner end of the transition rod are fixedly connected to the outer end of the transition rod 2. The rod end of the connecting rod 2a is fixedly connected to the transition rod counterweight 2b, so that the center of gravity of the transition rod 2 is adjusted to the position of the secondary flexible hinge 7; a primary lever counterweight is set at the rod end of the horizontal rod 3a of the primary lever Block 12 adjusts the center of gravity of the first-level lever to the position of the first-level fulcrum 5; on the second-level lever 1, it is located between the second-level fulcrum 8 and the second-level flexible hinge 7, and is set by a fixed cantilever 1a The secondary lever counterweight 1b adjusts the common center of gravity of the secondary lever 1, the transition rod 2, the connecting rod 2a and the transition rod counterweight 2b to the position of the secondary fulcrum 8.

In a specific implementation, the transition rod counterweight 2b can be removed, but this will reduce the loading accuracy of the force and narrow the range of the force value of the loading force.

At the position of the first-level fulcrum and the second-level fulcrum, the first-level lever and the second-level lever are respectively arranged on the base through the flexible hinges of each fulcrum. In order to eliminate the bending deformation and bending stress caused by gravity on the flexible hinge, avoid the bending caused by gravity The moment leads to the destruction of the flexible hinge, and the flexible hinges at the primary fulcrum and the secondary fulcrum are all set to be consistent with the direction of gravity.

The whole device generates a slight force by the weight, which is far less than the weight of the weight, and the larger the ratio of the length of the vertical rod 3b to the distance from the input end of the primary lever to the primary fulcrum 5, the greater the ratio of the length of the secondary lever 1 to the second The larger the ratio of the distance from the primary fulcrum 8 to the secondary flexible hinge 7, the smaller the micro force can be generated.

In specific implementation, the differential loading of horizontal micro force can be realized in the following two ways:

Method 1: Load the loading weights of the same mass at the two input ends, and the probe is at the initial position at this time; set the force sensor to keep at the initial position, change the mass difference of the loading weights at the two input ends, and make one of the input ends The loading force at the input end is F1a, and the loading force at the other input end is F1b, then the loaded force difference F1=F1a-F1b, after the force difference is reduced by the flexible hinge mechanism, it is loaded on the force sensor 11 through the probe, In order to obtain micro-forces of different sizes;

Method 2: Load the loading weights of the same mass at the two input ends. At this time, the probe is at the initial position, and then change the mass difference between the loading weights at the two input ends to make the probe offset, and the probe will be moved by the force sensor. Gradually move from the offset position to the initial position, the closer the force sensor is to the initial position, the greater the force of the probe on the force sensor, and finally the loading force is determined by the mass difference between the weights loaded at the two input ends and the displacement of the force sensor A non-contact displacement sensor can be installed at the probe. Through theoretical analysis, numerical calculation and experimental calibration, the relationship between the bias displacement of the probe and the loading force can be established under the difference in mass of the weights loaded at the two input ends. relation.

The device of the present invention can realize the loading of micro force below 10 ^-2 .

Claims (2)

1. A loading method of a differential horizontal micro-force loading device, characterized in that: The differential horizontal micro-force loading device is set as follows: with the vertically arranged secondary lever (1) as the central rod, in the same vertical plane, a pair of primary levers are symmetrically located at the center of the secondary lever (1). Both sides are connected with the secondary lever (1) through the transition rod (2) on each side respectively; The first-stage lever is an inverted "L"-shaped bar made of a horizontal bar (3a) and a vertical bar (3b), and the loading weight (4) is arranged on the bar end of the horizontal bar (3a) as the input end. The first-level fulcrum (5) is positioned at the middle part of the horizontal bar, and the bottom end of the vertical bar (3b) is connected to the outer end of the transition bar (2) by a first-order flexible hinge (6) at the bar side, and the transition bar (2) The inner end is connected on the force point of the secondary lever (1) through the secondary flexible hinge (7); The bottom end of described secondary lever (1) is set as secondary fulcrum (8), and the top of secondary lever (1) is free end, and probe (9) is set at the top of described secondary lever, with described The probe (9) is in contact with the force sensor (11) arranged on the micro-motion platform (10); A pair of connecting rods (2a) extending toward the inner end of the transition rod are fixedly connected to the outer end of the transition rod (2), and the transition rod counterweight is fixed at the rod end of the connecting rod (2a) ( 2b), the center of gravity of the transition rod (2) is adjusted to the position of the secondary flexible hinge (7); the primary lever counterweight (12) is set at the rod end of the horizontal bar (3a) of the primary lever ), so that the center of gravity of the primary lever is adjusted to the position of the primary fulcrum (5); on the secondary lever (1), it is between the secondary fulcrum (8) and the secondary flexible hinge (7) Set the secondary lever counterweight (1b) through the fixed cantilever (1a), so that the secondary lever (1), transition lever (2), connecting rod (2a) and transition lever counterweight (2b) The center of gravity is adjusted to the position of the secondary fulcrum (8); The loading method of the differential horizontal micro-force loading device is to realize differential loading in one of the following ways: Method 1: Load the loading weights of the same mass at the two input ends, and the probe is at the initial position at this time; set the force sensor to keep at the initial position, change the mass difference of the loading weights at the two input ends, and when the force Obtain different loading forces on the sensor; Method 2: Load the loading weights of the same mass at the two input ends. At this time, the probe is at the initial position, and then change the mass difference between the loading weights at the two input ends to make the probe offset, and the probe will be moved by the force sensor. Gradually move from the offset position to the initial position, the closer the force sensor is to the initial position, the greater the force of the probe on the force sensor, and finally the loading force is determined by the mass difference between the weights loaded at the two input ends and the displacement of the force sensor the size of. 2. the method for differential type horizontal micro-force loading device according to claim 1, is characterized in that: in described differential type horizontal micro-force loading device, at described primary fulcrum (5) and secondary fulcrum (8) ) position, the primary lever and the secondary lever are respectively arranged on the base through the flexible hinges of each fulcrum, and the flexible hinges of each fulcrum are suspended on the machine base to be consistent with the direction of gravity.

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