Contact type micro-nano probe with high dynamic response characteristic

Abstract

The invention discloses a contact type micro-nano probe with a high dynamic response characteristic, which is characterized in that an optical measuring unit is arranged in a measuring cylinder, and a measuring head unit is arranged below the measuring cylinder; an elastic mechanism is arranged between the two circular ring seats in the measuring head unit, a suspension sheet is arranged in the center area of the elastic mechanism, one side of the suspension sheet faces a plane mirror in the measuring cylinder, a probe is installed on the other side of the suspension sheet, the elastic mechanism is a magnetizer, and permanent magnets are arranged on the two sides of the magnetizer respectively; for vibration transmitted to the elastic mechanism in the working process of the probe, the elastic mechanism and the permanent magnets on the two sides form a damping unit through the eddy current effect, the damping effect is generated, the elastic mechanism tends to be stable more quickly after the probe is triggered, and the high dynamic response characteristic of the probe is obtained.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano measurement, and more specifically to a contact micro-nano probe with high dynamic response characteristics applied to a nano coordinate measuring machine, which can meet the rapid measurement requirements of micro-sized devices. Background Art

[0002] With the development of micro-nano processing technology, various micro-nano scale micro-devices have emerged one after another, such as micro-lenses, micro-gears, micro-chips, fuel injectors, etc. These micro-devices have complex shapes and high precision requirements. To meet the measurement requirements of such devices, a coordinate measuring machine with nano-level measurement accuracy is required. As one of the core components of the coordinate measuring machine, the dynamic response characteristics of the probe directly determine the overall measurement accuracy and measurement efficiency of the coordinate measuring machine.

[0003] A contact probe generally consists of three parts, namely a probe, an elastic mechanism, and a sensor. The elastic mechanism converts the displacement of the measuring ball in three-dimensional directions into a physical quantity that is convenient for the sensor to sense. According to different sensing principles, contact probes can be divided into: capacitive, inductive, resistive, and optical sensing types, etc. Improving the dynamic response speed of the sensor can improve the dynamic response characteristics of the probe. Directly weakening the source of vibration is also an important way to improve the dynamic response characteristics of the probe.

[0004] In the patent specification of the invention with the publication number CN 105698661 A, the applicant proposed a contact scanning probe for a micro-nano coordinate measuring machine, which uses a capacitive sensor as the sensing device. Compared with strain type, piezoresistive type, and inductive type, it improves the accuracy and dynamic response speed of the probe to a certain extent.

[0005] In the patent specification of the invention with the publication number CN 105758335 A, the applicant proposed a three-dimensional micro-nano contact scanning probe, which uses an optical sensor to sense, and obtains a faster dynamic response speed compared with a capacitive probe.

[0006] The above two methods shorten the response time of the probe and improve the dynamic response speed of the probe by replacing the sensor with a high response speed. However, the vibration attenuation of the elastic mechanism during the measurement process takes time, and the required stabilization time of the probe in actual use directly limits the improvement of the measurement efficiency. Summary of the Invention

[0007] The present invention aims to avoid the deficiencies of the above-mentioned prior art, and provides a contact micro-nano probe with high dynamic response characteristics, in order to obtain high measurement accuracy and dynamic response speed, and improve the measurement efficiency.

[0008] The present invention adopts the following technical solutions to solve the technical problems:

[0009] The characteristics of the contact micro-nano probe with high dynamic response characteristics of the present invention are as follows:

[0010] A measuring unit composed of a laser, an optical mirror and a quadrant detector is arranged in the measuring cylinder;

[0011] A probe unit is arranged below the measuring cylinder; the probe unit is provided with an elastic mechanism between two circular ring seats, a floating sheet is arranged in the central area of the elastic mechanism, and the floating sheet is connected to the outer ring of the elastic mechanism through a cantilever, forming a floating mechanism of the floating sheet in the center of the circular ring seat; on the plane on one side of the floating sheet facing the inside of the measuring cylinder, a central plane mirror is fixedly arranged at the central position of the floating sheet; on the plane on the other side of the floating sheet facing the outside of the measuring cylinder, a probe is fixedly installed at the center of the floating sheet, and a probe tip is fixedly installed at the end of the probe;

[0012] The elastic mechanism is set as a magnetic conductor, and two annular permanent magnets are respectively arranged on the upper and lower sides of the magnetic conductor; for the vibration transmitted to the elastic mechanism during the working process of the probe, the eddy current effect is utilized to form a damping module between the elastic mechanism and the two annular permanent magnets, and the damping effect generated by the damping module enables the elastic mechanism to tend to be stable faster after the probe is triggered, obtaining the high dynamic response characteristics of the probe.

[0013] The characteristics of the contact micro-nano probe with high dynamic response characteristics of the present invention also lie in that: in the damping unit, the two annular permanent magnets are respectively the upper annular permanent magnet and the lower annular permanent magnet arranged on the upper and lower sides of the elastic mechanism in a one-to-one correspondence manner, and the upper annular permanent magnet and the lower annular permanent magnet are fixedly connected to the elastic mechanism by using the upper permanent magnet fixing seat and the lower permanent magnet fixing seat on their respective sides.

[0014] The characteristics of the contact micro-nano probe with high dynamic response characteristics of the present invention also lie in that: the upper permanent magnet fixing seat and the lower permanent magnet fixing seat are embedded with the outer ring concave-convex structure of the circular ring seat on their respective sides to form two discs on both sides of the elastic mechanism; the two discs are fixedly connected to the elastic mechanism by screws at the outer ring.

[0015] The contact micro-nano probe with high dynamic response characteristics of the present invention is characterized in that:

[0016] The structure of the measuring unit is set as follows: in the measuring cylinder, a laser fixing seat, a two-dimensional adjustment seat and a quadrant detector fixing seat are respectively arranged on one side wall; the laser is fixedly installed on the laser fixing seat by using the laser fixing seat upper cover; a plane mirror is arranged on one side of the two-dimensional adjustment seat facing the laser; the quadrant detector is fixedly installed on the quadrant detector fixing seat by using the quadrant detector fixing seat pressing plate;

[0017] The optical path structure of the measurement unit is as follows: The collimated light emitted by the laser is projected onto the plane mirror on the two-dimensional adjustment base. After being reflected by the plane mirror, it is projected onto the central plane mirror on the suspension sheet, and after being reflected by it, it is projected onto the quadrant detector to achieve optical measurement.

[0018] The feature of the contact micro-nano probe with high dynamic response characteristics of the present invention also lies in: setting the two-dimensional adjustment base as an angle adjustment structure, and by adjusting the two-dimensional angle of the two-dimensional adjustment base, part of the reflected light of the plane mirror is projected onto the central position of the central plane mirror.

[0019] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0020] 1. Without using a filtering algorithm and a complex vibration damping device, the present invention adds a specific damping module to the probe system. When the elastic mechanism vibrates, the eddy current damping force generated by the damping module reduces the vibration decay time of the elastic mechanism, effectively improving the dynamic characteristics of the probe.

[0021] 2. The present invention does not need to adjust the structure of the probe elastic mechanism. Without increasing the stiffness of the elastic mechanism, the stable time of the probe can be reduced by about 50%.

[0022] 3. The added damping module of the present invention is a passive system, which does not require external power supply. Only two annular permanent magnets need to be set on both sides of the elastic mechanism. The structure is simple, the assembly is flexible, and it has high practicability.

[0023] 4. The damping module of the present invention has self-adaptability. The larger the vibration amplitude of the elastic mechanism, the larger the eddy current value generated by the damping module, and the more obvious the hindering effect of the corresponding magnetic field force. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the structural decomposition of the probe module in the present invention;

[0026] Figure 3 It is a schematic diagram of the measurement optical path structure in the present invention;

[0027] Figure 4 It is a schematic diagram of the structure of the two-dimensional adjustment base in the present invention;

[0028] Figure 5 It is a schematic diagram of the structural decomposition of the fixed structure of the quadrant detector in the present invention;

[0029] Figure 6 It is a schematic diagram of the structural decomposition of the fixed structure of the laser in the present invention;

[0030] Figure 7 Schematic diagram of the magnetic field of the annular permanent magnet in the present invention;

[0031] Figure 8 Schematic diagram of eddy current in the elastic mechanism in the present invention;

[0032] Figure 9 Output curve of the probe without the annular magnet;

[0033] Figure 10 Output curve of the probe after setting the annular magnet;

[0034] Reference numerals in the figure: 1a upper cylinder cover, 1b lower cylinder cover, 2a laser fixing seat, 2b laser, 2c upper laser seat, 3a four-quadrant detector fixing seat, 3b four-quadrant detector, 3c upper fixing cover of the four-quadrant detector, 4 two-dimensional adjustment seat, 5 probe unit, 6a upper permanent magnet, 6b lower permanent magnet, 7a upper permanent magnet fixing seat, 7b lower permanent magnet fixing seat, 8 ring seat, 9 elastic mechanism, 10 probe, 11 central plane mirror, 12 plane mirror, 13 adjustment screw, 14 suspension sheet. Specific embodiments

[0035] The structural arrangement of the contact micro-nano probe with high dynamic response characteristics in this embodiment includes:

[0036] See Figure 1 and Figure 2 , in the probe unit 5, the ring seat 8 on the upper layer of the elastic mechanism 9, that is, the upper ring seat, is fixedly connected to the lower cylinder cover 1b. The elastic mechanism 9 is clamped between the upper and lower ring seats. There are evenly distributed "S-shaped curve structure" cantilevers in the elastic mechanism 9. In the middle of the elastic mechanism 9 is the suspension sheet 14. Both ends of each cantilever of the elastic mechanism are integrally formed with the central suspension sheet 14 and the outer ring of the circular elastic mechanism 9, and the outer ring of the circular elastic mechanism 9 is fixedly connected to the upper and lower ring seats, forming a suspension mechanism with the suspension sheet 14 in the center of the ring seat; on both the upper and lower sides of the elastic mechanism 9 and at a distance of 0.7 mm from the elastic mechanism, there is respectively provided an annular permanent magnet with an inner diameter of 14 mm and an outer diameter of 30 mm, which are respectively Figure 2 the upper permanent magnet 6a and the lower permanent magnet 6b shown in. The upper permanent magnet 6a is fixedly installed by the upper permanent magnet fixing seat 7a, and the lower permanent magnet 6b is fixedly installed by the lower permanent magnet fixing seat 7b; on the plane on the inner side of the suspension sheet 14 facing the cylinder, a central plane mirror 11 is fixedly provided at the central position of the suspension sheet 14; on the plane on the outer side of the suspension sheet 14 facing the cylinder, the probe 10 is fixedly installed at the center of the suspension sheet, and the measuring ball is fixedly installed at the end of the probe.

[0037] See Figure 1 , Figure 3 , Figure 4 ,Figure 5 and Figure 6 A measuring unit, in which a laser fixing seat 2a, a two-dimensional adjustment seat 4 and a quadrant detector fixing seat 3a are arranged on the inner side of a cylindrical wall. The cylindrical wall is fixedly connected to an upper cylinder cover 1a. A laser 2b is fixedly installed by the laser fixing seat 2a and an upper cover 2c of the laser fixing seat. A plane mirror 12 is arranged on one side of the two-dimensional adjustment seat 4 facing the laser 2b. A quadrant detector 3b is fixedly installed by the quadrant detector fixing seat 3a and a pressing plate 3c of the quadrant detector fixing seat. The optical path structure of the measuring unit is set as follows: the collimated light emitted by a laser 6a is projected onto the plane mirror 12 on the two-dimensional adjustment seat 4. After being reflected by the plane mirror 12, it is projected onto a central plane mirror 11 on a suspension sheet 14, and finally projected onto the quadrant detector 3b after being reflected by the central plane mirror 11.

[0038] See Figure 7 and Figure 8 In this embodiment, an upper permanent magnet 6a and a lower permanent magnet 6b form a magnetic field. An elastic mechanism 9 is located between the two permanent magnets. Therefore, the elastic mechanism 9 is in the magnetic field formed by the permanent magnets. During the working process of the probe, after the probe 10 collides with the object to be measured and then separates from the object to be measured, the probe 10 will have a process in which its vibration gradually stabilizes. The probe 10 is fixedly connected to the elastic mechanism 9 by gluing, and the elastic mechanism 9 will also have a process in which its vibration gradually stabilizes. The material of the elastic mechanism 9 is beryllium bronze. When the elastic mechanism 9 generates vibration during the working process of the probe, due to the eddy current effect, eddy currents will be generated in the elastic mechanism 9. As Figure 8 shown, when the elastic mechanism generates vibration, clockwise eddy currents are generated in the elastic mechanism. The magnetic field generated by the eddy currents interacts with the magnetic field of the permanent magnet, generating a magnetic force in the opposite direction to the movement direction of the elastic mechanism 9, which will hinder the relative movement between the elastic mechanism 9 and the magnetic field, generating a damping effect, making the elastic mechanism 9 tend to be more stable faster after the probe is triggered, thereby improving the dynamic response characteristics of the probe.

[0039] In specific implementation, the corresponding structure also includes:

[0040] As Figure 2 shown, the circular ring seat 8 is divided into an upper circular ring seat and a lower circular ring seat, which are fixedly embedded with the upper permanent magnet fixing seat 7a and the lower permanent magnet fixing seat 7b respectively. Between the elastic mechanism 9 and the two circular ring seats 8, and between the circular ring seat 8 and the upper permanent magnet fixing seat 7a and the lower permanent magnet fixing seat 7b, screw fixed connections are adopted.

[0041] As Figure 1 and Figure 6As shown, a laser fixing base 2a is arranged on the inner side of the cylinder wall, and the laser fixing base 2a is fixedly connected to the cylinder wall by screws. The laser 2b is placed in the groove of the laser fixing base 2a, and a laser fixing upper cover 2c is provided and fixedly connected to the laser fixing base 2a by screws to fix the laser 2b.

[0042] As Figure 1 and Figure 5 shown, a four-quadrant detector fixing base 3a is arranged on the inner side of the cylinder wall, and the four-quadrant detector fixing base 3a is fixedly connected to the cylinder wall by screws. The four-quadrant detector 3b is embedded in the four-quadrant detector fixing base 3a, and a fixing upper cover 3c is arranged on the back side of the four-quadrant detector to fix it.

[0043] As Figure 3 and Figure 4 shown, a two-dimensional adjustment base 4 capable of angle adjustment is provided. A plane mirror 12 is arranged on the laser direction side of the two-dimensional adjustment base 4. The adjustment screw 13 is adjusted so that a part of the reflected light of the plane mirror 12 is projected at the center position of the central plane mirror 11.

[0044] The working principle of the measurement unit in this embodiment is as Figure 2 and Figure 3 shown:

[0045] The light emitted from the laser 2b is reflected by the plane mirror 12 on the two-dimensional adjustment base 4 and then projected onto the central plane mirror 11, and then reflected by the central plane mirror 11 and projected onto the four-quadrant detector 3b. When the probe 10 is touched by a horizontal or vertical force, the suspension piece 14 and the central plane mirror 11 undergo a lateral or vertical offset, resulting in a change in the position of the light spot projected on the four-quadrant detector 3b, and further resulting in a change in the magnitude of the current signal output by the four-quadrant detector 3b. The current / voltage conversion circuit is used to convert the current signals output from the four quadrants into voltage signals, and the change in the position of the light spot is converted into a displacement signal for output.

[0046] Performance test of the contact micro-nano probe with high dynamic response characteristics in this embodiment:

[0047] Taking the vibration process after the probe is separated from the measured object as an example:

[0048] A three-dimensional high-precision nano-positioning platform (Physik Instrumente, model P-561.3CD, Germany) is selected to provide the trigger displacement standard quantity to test the probe. The output value of the probe is sampled every 10 ms, and the output curve of the probe is recorded. The output curve of the probe without the ring magnet is as Figure 9 shown, and the output curve of the probe with the permanent magnet set is as Figure 10 shown.

[0049] Figure 9 It can be seen that after the probe is separated from the object under test and generates vibration, after about 230 samplings, that is, after about 2.3 s, the output value can be stabilized within 1 μm.

[0050] Figure 10 It can be seen that after the permanent magnet is set, under the influence of the eddy current effect between the elastic mechanism and the magnetic field, after about 120 samplings after the probe generates vibration, that is, after about 1.2 s, the output value can be stabilized within 1 μm. The time required for the probe output to be stabilized within 1 μm is reduced by about 50% compared with the case without the toroidal magnet, and the elastic mechanism tends to be stable faster, greatly improving the dynamic response characteristics of the probe. If there are high requirements, it can be achieved by replacing the toroidal magnet to increase the magnetic field strength and magnetic field quality.

Claims

1. A contact micro-nano probe with high dynamic response characteristics, characterized in that: At A measurement unit composed of a laser, an optical mirror and a quadrant detector is arranged in the measurement cylinder; A probe unit (5) is arranged below the measurement cylinder; the probe unit (5) is provided with an elastic mechanism (9) between two circular ring seats (8), and a suspension sheet (14) is arranged in the central area of the elastic mechanism (9). The suspension sheet (14) is connected to the outer ring of the elastic mechanism through a cantilever, forming a suspension mechanism of the suspension sheet (14) in the center of the circular ring seat (8); on the plane on one side of the suspension sheet (14) facing the inside of the measurement cylinder, a central plane mirror (11) is fixedly arranged at the central position of the suspension sheet (14); on the plane on one side of the suspension sheet (14) facing the outside of the measurement cylinder, a probe (10) is fixedly installed at the center of the suspension sheet, and a probe ball is fixedly installed at the end of the probe (10). The elastic mechanism (9) is set as a magnetic conductor, and two annular permanent magnets are respectively arranged on the upper and lower sides of the magnetic conductor; for the vibration transmitted to the elastic mechanism (9) during the working process of the probe (10), the eddy current effect is used to form a damping module between the elastic mechanism (9) and the two annular permanent magnets, and the damping effect generated by the damping module enables the elastic mechanism (9) to tend to be stable faster after the probe is triggered, obtaining the high dynamic response characteristics of the probe (10).

2. The contact micro-nano probe with high dynamic response characteristics according to claim 1, characterized in that: in In the damping unit, the two annular permanent magnets are respectively the upper annular permanent magnet (6a) and the lower annular permanent magnet (6b) arranged on the upper and lower sides of the elastic mechanism (9) in a one-to-one correspondence. The upper annular permanent magnet (6a) and the lower annular permanent magnet (6b) are fixedly connected to the elastic mechanism (9) by using the upper permanent magnet fixing seat (7a) and the lower permanent magnet fixing seat (7b) on their respective sides.

3. The contact micro-nano probe with high dynamic response characteristics according to claim 2, characterized in that: The upper permanent magnet fixing seat (7a) and the lower permanent magnet fixing seat (7b) are embedded with the outer ring concave-convex structure of the circular ring seat (8) on their respective sides to form two disks located on both sides of the elastic mechanism (9); the two disks are fixedly connected to the elastic mechanism (9) by screws on the outer ring.

4. The contact micro-nano probe with high dynamic response characteristics according to claim 1, characterized in that: The structure of the measurement unit is set as follows: in the measurement cylinder, a laser fixing seat (2a), a two-dimensional adjustment seat (4) and a quadrant detector fixing seat (3a) are respectively arranged on one side wall; the laser (2b) is fixedly installed on the laser fixing seat (2a) by using the laser fixing seat upper cover (2c); the two-dimensional adjustment seat (4) is provided with a plane mirror (12) on the side facing the laser (2b); the quadrant detector (3b) is fixedly installed on the quadrant detector fixing seat (3a) by using the quadrant detector fixing seat pressing plate (3c). The optical path structure of the measurement unit is as follows: The collimated light emitted by the laser (6a) is projected onto the plane mirror (12) on the two-dimensional adjustment base (4). After being reflected by the plane mirror (12), it is projected onto the central plane mirror (11) on the floating sheet (14), and after being reflected by it, it is projected onto the quadrant detector (3b) to achieve optical measurement.

5. The contact micro-nano probe with high dynamic response characteristics according to claim 4, characterized in that: The two-dimensional adjustment base (4) is set as an angle adjustment structure. By adjusting the two-dimensional angle of the two-dimensional adjustment base (4), part of the reflected light of the plane mirror (12) is projected onto the central position of the central plane mirror (11).

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