A 24 leaf three-dimensional equal force scanning probe head

Abstract

The application discloses a 24-spring three-dimensional equal-force scanning probe, which comprises a probe mounting base, a circuit processing module, a signal amplification module, a probe body, a balance spring, a trigger switch, a probe seat, a probe connector, a probe, a probe ball, a magnetic attraction structure, an x-direction guiding mechanism, a y-direction guiding mechanism and a z-direction guiding mechanism. In the application, 24 elastic springs are used in the three guiding mechanisms. Except that the two groups of elastic springs in the z-direction guiding mechanism are of the same size, the two groups of elastic springs in the x-direction guiding mechanism and the y-direction guiding mechanism are of different sizes. Through stress analysis and optimization design, three-dimensional equal-force measurement of the three-dimensional scanning probe can be realized. In the application, the three guiding mechanisms are all provided with differential capacitance sensors and two groups of unequal-area plate capacitance sensors arranged in quadrature, so that redundant measurement of six degrees of freedom of the guiding mechanisms can be realized. The device has wide application, and is especially suitable for high-precision scanning probes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precision measurement, and particularly to a 24-spring three-dimensional equal force scanning probe. BACKGROUND

[0002] As a key component of coordinate measuring machine, the development level of precision probe directly affects the measurement accuracy, working performance, use efficiency and flexibility of coordinate measuring machine. The development history of coordinate measuring machine also shows that only when the precision probe provides new touch principle and new measurement accuracy for coordinate measuring machine, the coordinate measuring machine can have a fundamental change. In other words, the precision probe is the main factor limiting the accuracy and measurement speed of coordinate measuring machine, and whether the coordinate measuring machine can meet the modern measurement requirements also depends on the continuous innovation and development of the precision probe system. The three-dimensional equal force measurement of the probe is the key to ensure the isotropy of the probe. SUMMARY

[0003] The three-dimensional probe usually adopts the configuration of three independent guide mechanisms in series. The inside of each guide mechanism is connected between the fixed part and the moving part by an elastic element. When the probe needle is deformed by force, the probe transmits the force to each guide mechanism, so that the moving part in the guide mechanism generates a displacement relative to the fixed part, and the relative displacement can be sensed by the internal capacitive sensor. The elastic force generated after the deformation of the elastic element offsets the external force received by the probe needle and the gravity of the related structure. By analyzing the force conditions of the probe needle, each guide mechanism and the elastic element, spring sheets of different sizes are designed, and the purpose of realizing the three-dimensional equal force capability of the precision scanning probe is finally achieved.

[0004] The above object is achieved by the following technical solutions:

[0005] A 24-spring three-dimensional equal force scanning probe head, comprising a probe head mounting seat, a circuit processing module, a signal amplification module, a probe head body, a balance spring, a trigger switch, a stylus seat, a stylus connector, a stylus, a probe ball, a magnetic attraction structure, an x-direction guide mechanism, a y-direction guide mechanism, and a z-direction guide mechanism; the x-direction guide mechanism comprises a first fixed plate, a second fixed plate, a first fixed plate first upper pressing plate, a first fixed plate second upper pressing plate, a differential plate, a first moving plate first upper pressing plate, a first moving plate second upper pressing plate, a second moving plate upper pressing plate, a first moving plate, a second moving plate, a first moving plate lower pressing plate, a second moving plate first lower pressing plate, a second moving plate second lower pressing plate, a first fixed plate first lower pressing plate, a first fixed plate second lower pressing plate, a second fixed plate first lower pressing plate, a second fixed plate first upper pressing plate, a second fixed plate second upper pressing plate, an x-direction guide mechanism first group of spring pieces, an x-direction guide mechanism second group of spring pieces, an unequal-area polar plate capacitor sensor first fixed polar plate, an unequal-area polar plate capacitor sensor second fixed polar plate, an unequal-area polar plate capacitor sensor first movable polar plate, and an unequal-area polar plate capacitor sensor second movable polar plate; the y-direction guide mechanism comprises a first fixed plate, a second fixed plate, a first fixed plate first upper pressing plate, a first fixed plate second upper pressing plate, a differential plate, a first moving plate first upper pressing plate, a first moving plate second upper pressing plate, a second moving plate upper pressing plate, a first moving plate, a second moving plate, a first moving plate lower pressing plate, a second moving plate first lower pressing plate, a second moving plate second lower pressing plate, a first fixed plate first lower pressing plate, a first fixed plate second lower pressing plate, a second fixed plate first lower pressing plate, a second fixed plate first upper pressing plate, a second fixed plate second upper pressing plate, a y-direction guide mechanism first group of spring pieces, a y-direction guide mechanism second group of spring pieces, an unequal-area polar plate capacitor sensor first fixed polar plate, an unequal-area polar plate capacitor sensor second fixed polar plate, an unequal-area polar plate capacitor sensor first movable polar plate, and an unequal-area polar plate capacitor sensor second movable polar plate; the z-direction guide mechanism comprises a vertical connecting plate, a first fixed plate, a second fixed plate, a first fixed plate first upper pressing plate, a first fixed plate second upper pressing plate, a differential plate, a first moving plate first upper pressing plate, a first moving plate second upper pressing plate, a second moving plate upper pressing plate, a first moving plate, a second moving plate, a first moving plate lower pressing plate, a second moving plate first lower pressing plate, a second moving plate second lower pressing plate, a first fixed plate first lower pressing plate, a first fixed plate second lower pressing plate, a second fixed plate first lower pressing plate, a second fixed plate first upper pressing plate, a second fixed plate second upper pressing plate, a z-direction guide mechanism first group of spring pieces, a z-direction guide mechanism second group of spring pieces, an unequal-area polar plate capacitor sensor first fixed polar plate, an unequal-area polar plate capacitor sensor second fixed polar plate, an unequal-area polar plate capacitor sensor first movable polar plate, and an unequal-area polar plate capacitor sensor second movable polar plate.

[0006] The upper end of the probe body is mounted on the guide rail of the coordinate measuring machine via a probe mounting base, and the lower end is connected to the stylus holder via a balance spring. The balance spring is used to counteract part of the weight of the stylus holder and the stylus. The x-axis guiding mechanism, y-axis guiding mechanism, and z-axis guiding mechanism are connected in series from top to bottom. The upper end of the x-axis guiding mechanism is fixed to the probe mounting base, and the lower end is connected to the stylus mounting base via a magnetic attraction structure. A trigger switch is installed between the fixed part and the moving part in the z-axis guiding mechanism. The trigger switch and the magnetic attraction structure together realize the anti-collision function of the probe. The differential capacitance sensor in each guiding mechanism and the two sets of orthogonally arranged unequal surface plate capacitance sensors are used to realize the redundant measurement of the 6 degrees of freedom of the guiding mechanism. The circuit processing module and the signal amplification module complete the data acquisition and preprocessing of the sensors inside each guiding mechanism.

[0007] In the z-direction guiding mechanism, both the first and second sets of z-direction guiding springs bear the weight of the z-direction guiding mechanism in the tangential direction, and the two sets of springs are designed to have the same size. In the y-direction guiding mechanism, the first and second sets of y-direction guiding springs bear the weight of the z-direction guiding mechanism and the y-direction guiding mechanism in the tangential and axial directions, respectively, and the two sets of springs are designed to have different sizes. In the x-direction guiding mechanism, the first and second sets of x-direction guiding springs bear the weight of the z-direction guiding mechanism, the y-direction guiding mechanism, and the x-direction guiding mechanism in the axial and tangential directions, respectively, and the two sets of springs are designed to have different sizes.

[0008] This invention has the following characteristics and beneficial effects:

[0009] 1. In this invention, a total of 24 elastic springs are used in the three guiding mechanisms. Except for the two sets of elastic springs in the z-direction guiding mechanism which have the same size, the two sets of elastic springs in the x-direction guiding mechanism and the y-direction guiding mechanism have different sizes. Through force analysis and optimization design, three-dimensional equal force measurement of the three-dimensional scanning probe can be realized.

[0010] 2. In this invention, all three guiding mechanisms are equipped with differential capacitance sensors and two sets of orthogonally arranged unequal surface plate capacitance sensors, which can realize redundant measurement of 6 degrees of freedom for each guiding mechanism.

[0011] The device of this invention has a wide range of applications, and is especially suitable for high-precision scanning probes. Attached Figure Description

[0012] Figure 1 This is a structural diagram of the three-dimensional constant force scanning probe.

[0013] Figure 2 This is a structural diagram of the probe holder for a three-dimensional constant force scanning probe.

[0014] Figure 3This is a diagram of the internal structure of the z-direction guide mechanism of a three-dimensional constant force scanning probe.

[0015] Figure 4 This is a diagram of the internal structure of the y-direction guide mechanism of a three-dimensional constant force scanning probe.

[0016] Figure 5 This is a diagram of the internal structure of the x-direction guide mechanism of a three-dimensional constant force scanning probe.

[0017] Figure 6 This is a schematic diagram showing the location of the bolt connection holes on the first fixing plate.

[0018] Figure 7 This is a schematic diagram showing the location of the bolt connection holes for the first movable plate.

[0019] Figure 8 This is a schematic diagram showing the location of the positioning holes for the magnetic nail in the magnetic attraction structure.

[0020] In the diagram, the markings are: 1-Probe mounting base; 2-Circuit processing module; 3-Signal amplification module; 4-Probe body; 5-Balance spring; 6-Trigger switch; 7-Probe holder; 8-Probe connector; 9-Probe; 10-Probe ball; 11-Magnetic attraction structure; 12-Z-direction guide mechanism; 13-Y-direction guide mechanism; 14-X-direction guide mechanism; 15-Vertical connecting plate; 16-1-First fixing plate; 16-2-Second fixing plate; 17-1-First fixing plate. 17-2-First fixed plate, first upper pressure plate; 18-Differential plate; 19-1-First moving plate, first upper pressure plate; 19-2-First moving plate, second upper pressure plate; 20-Second moving plate, upper pressure plate; 21-1-First moving plate; 21-2-Second moving plate; 22-First moving plate, lower pressure plate; 23-1-Second moving plate, first lower pressure plate; 23-2-Second moving plate, second lower pressure plate; 24-1-First fixed plate, first lower pressure plate. Pressure plate; 24-2- First fixed plate, second lower pressure plate; 25-1- Second fixed plate, first lower pressure plate; 25-2- Second fixed plate, second lower pressure plate; 26- Z-direction guide mechanism, first set of springs; 27- Z-direction guide mechanism, second set of springs; 28- Unequal surface area positive plate capacitive sensor, first fixed plate; 29- Unequal surface area positive plate capacitive sensor, second fixed plate; 30- Unequal surface area positive plate capacitive sensor, first moving plate; 31- Unequal surface area positive plate capacitive sensor, second moving plate; 32- Y-direction guide mechanism, first set of springs; 33- Y-direction guide mechanism, second set of springs; 34-1- Second fixed plate, first upper pressure plate; 34-2- Second fixed plate, second upper pressure plate; 35- X-direction guide mechanism, first set of springs; 36- X-direction guide mechanism, second set of springs; 37- First fixed plate threaded connection hole; 38- First moving plate threaded connection hole; 39- Magnetic structure magnetic nail positioning hole; 40- Vertical connecting plate threaded connection hole. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0022] like Figure 1 and Figure 2 The three-dimensional equal force scanning probe with 24 springs shown includes a probe mounting base 1, a circuit processing module 2, a signal amplification module 3, a probe body 4, a balance spring 5, a trigger switch 6, a probe holder 7, a probe connector 8, a probe 9, a probe ball 10, a magnetic attraction structure 11, an x-direction guiding mechanism 12, a y-direction guiding mechanism 13, and a z-direction guiding mechanism 14.

[0023] like Figure 5 As shown, coordinate axis z3 is the direction of gravity, and coordinate axis x3 is the direction of guidance. The x-direction guiding mechanism includes a first fixed plate 16-1, a second fixed plate 16-2, a first upper pressure plate 17-1 of the first fixed plate, a second upper pressure plate 17-2 of the first fixed plate, a differential plate 18, a first upper pressure plate 19-1 of the first moving plate, a second upper pressure plate 19-2 of the first moving plate, a second upper pressure plate 20 of the second moving plate, a first moving plate 21-1 of the first moving plate, a second moving plate 21-2 of the second moving plate, a lower pressure plate 22 of the first moving plate, a first lower pressure plate 23-1 of the second moving plate, and a second lower pressure plate 23-2 of the second moving plate. First fixed plate, first lower pressure plate 24-1; first fixed plate, second lower pressure plate 24-2; second fixed plate, first lower pressure plate 25-1; second fixed plate, first lower pressure plate 25-2; x-direction guide mechanism, first set of springs 35; x-direction guide mechanism, second set of springs 36; unequal surface area positive plate capacitive sensor, first fixed plate 28; unequal surface area positive plate capacitive sensor, second fixed plate 29; unequal surface area positive plate capacitive sensor, first moving plate 30; unequal surface area positive plate capacitive sensor, second moving plate 31.

[0024] like Figure 4As shown, coordinate axis z2 is the direction of gravity, and coordinate axis y2 is the guiding direction. The y-direction guiding mechanism includes a first fixed plate 16-1, a second fixed plate 16-2, a first upper pressure plate 17-1 of the first fixed plate, a second upper pressure plate 17-2 of the first fixed plate, a differential plate 18, a first upper pressure plate 19-1 of the first moving plate, a second upper pressure plate 19-2 of the first moving plate, a second upper pressure plate 20 of the second moving plate, a first moving plate 21-1 of the first moving plate, a second moving plate 21-2 of the second moving plate, a lower pressure plate 22 of the first moving plate, a first lower pressure plate 23-1 of the second moving plate, and a second lower pressure plate 23-2 of the second moving plate. First fixed plate, first lower pressure plate 24-1; first fixed plate, second lower pressure plate 24-2; second fixed plate, first lower pressure plate 25-1; second fixed plate, first lower pressure plate 25-2; y-direction guide mechanism, first set of springs 32; y-direction guide mechanism, second set of springs 33; unequal surface area positive plate capacitive sensor, first fixed plate 28; unequal surface area positive plate capacitive sensor, second fixed plate 29; unequal surface area positive plate capacitive sensor, first moving plate 30; unequal surface area positive plate capacitive sensor, second moving plate 31.

[0025] like Figure 3 As shown, the coordinate axis z1 is the direction of gravity and also the guiding direction. The z-direction guiding mechanism includes a vertical connecting plate 15, a first fixed plate 16-1, a second fixed plate 16-2, a first upper pressure plate 17-1 of the first fixed plate, a second upper pressure plate 17-2 of the first fixed plate, a differential plate 18, a first upper pressure plate 19-1 of the first moving plate, a second upper pressure plate 19-2 of the first moving plate, a second upper pressure plate 20 of the second moving plate, a first moving plate 21-1 of the first moving plate, a second moving plate 21-2 of the second moving plate, a lower pressure plate 22 of the first moving plate, a first lower pressure plate 23-1 of the second moving plate, and a second lower pressure plate of the second moving plate. 23-2, First fixed plate, first lower pressure plate; 24-1, First fixed plate, second lower pressure plate; 24-2, Second fixed plate, first lower pressure plate; 25-1, Second fixed plate, first lower pressure plate; 25-2, Z-direction guide mechanism, first set of springs; 26, Z-direction guide mechanism, second set of springs; 27, Unequal surface area positive plate capacitive sensor, first fixed plate; 28, Unequal surface area positive plate capacitive sensor, second fixed plate; 29, Unequal surface area positive plate capacitive sensor, first moving plate; 30, Unequal surface area positive plate capacitive sensor, second moving plate; 31.

[0026] The z-direction guide mechanism 12 and the y-direction guide mechanism 13 are connected via the threaded connection hole 40 on the vertical connecting plate 15 and the threaded connection hole 37 on the first fixed plate 16-1. The y-direction guide mechanism 13 and the x-direction guide mechanism 14 are connected via the threaded connection hole 38 on the first moving plate 21-1 and the threaded connection hole 37 on the first fixed plate 16-1. The x-direction guide mechanism 15 and the probe mounting base 1 are connected via the threaded connection hole 38 on the first moving plate 21-1 and the threaded connection hole on the probe mounting base 1.

[0027] The probe mounting base 1 is fixedly connected to the probe body 4 through four threaded holes on both sides; the circuit processing module 2 and the signal amplification module 3 are fixedly connected to the probe mounting base 1 through threaded holes. The x-guide mechanism 14, y-guide mechanism 13, and z-guide mechanism 12, which are already fixedly installed in series, are fixedly connected to the probe mounting base 1 by a threaded connection. A trigger switch 6, which is fixedly connected by a thread, is installed between the y-guide mechanism 13 and the z-guide mechanism 12. The lower end face of the first moving plate pressure plate 22 in the z-guide mechanism 12 has three magnetic nail positioning holes 39. Magnetic structures 11 are installed in the magnetic nail positioning holes 39 and are fixedly connected to the probe mounting base 7 through the magnetic structures 11. A balance spring 5 is also installed between the probe body 4 and the probe mounting base 7 to offset part of the weight of the probe base 7 and the probe 9. The trigger switch 6 and the magnetic structures 11 together realize the anti-collision function of the probe. Differential capacitance sensors 28 and two sets of orthogonally arranged unequal-area plate capacitance sensors in each guiding mechanism are used to achieve redundant measurement of the 6 degrees of freedom of the guiding mechanism. Circuit processing module 2 and signal amplification module 3 are used to realize data acquisition and preprocessing of the sensors inside each guiding mechanism.

[0028] In the z-direction guide mechanism 12, the first set of z-direction guide springs 26 and the second set of z-direction guide springs 27 both bear the weight of the z-direction guide mechanism in the tangential direction, and the two sets of springs are designed to have the same size. In the y-direction guide mechanism 13, the first set of y-direction guide springs 32 and the second set of y-direction guide springs 33 bear the weight of the z-direction guide mechanism 12 and the y-direction guide mechanism 13 in the tangential and axial directions, respectively, and the two sets of springs are designed to have different sizes. In the x-direction guide mechanism 14, the first set of x-direction guide springs 35 and the second set of x-direction guide springs 36 bear the weight of the z-direction guide mechanism 12, the y-direction guide mechanism 13, and the x-direction guide mechanism 14 in the axial and tangential directions, respectively, and the two sets of springs are designed to have different sizes.

[0029] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention, and various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be embodied in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown in this method, but is required to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three-dimensional constant force scanning probe with 24 reeds, characterized in that: The system includes a probe mounting base, a circuit processing module, a signal amplification module, a probe body, a balance spring, a trigger switch, a probe holder, a probe connector, a probe, a probe ball, a magnetic suction structure, an x-axis guiding mechanism, a y-axis guiding mechanism, and a z-axis guiding mechanism. The x-axis guiding mechanism includes a first fixed plate, a second fixed plate, a first upper pressure plate of the first fixed plate, a second upper pressure plate of the first fixed plate, a differential plate, a first upper pressure plate of the first movable plate, a second upper pressure plate of the first movable plate, a second upper pressure plate of the second movable plate, a first movable plate, a second movable plate, a lower pressure plate of the first movable plate, a first lower pressure plate of the second movable plate, a second lower pressure plate of the second movable plate, a first lower pressure plate of the first fixed plate, a second lower pressure plate of the first fixed plate, and so on. The system comprises two fixed plates: a first lower pressure plate, a second upper pressure plate, and a second upper pressure plate; a first set of springs for the x-direction guide mechanism; a second set of springs for the x-direction guide mechanism; a first fixed electrode plate, a second fixed electrode plate, a first moving electrode plate, and a second moving electrode plate for the unequal-area plate capacitance sensor; and a y-direction guide mechanism comprising a first fixed plate, a second fixed plate, a first upper pressure plate, a second upper pressure plate, a differential plate, a first upper pressure plate, a second upper pressure plate, a second upper pressure plate, a first moving plate, a second moving plate, and a lower pressure plate. The system comprises: a second moving plate with a first lower pressure plate, a second moving plate with a second lower pressure plate, a first fixed plate with a first lower pressure plate, a first fixed plate with a second lower pressure plate, a second fixed plate with a first lower pressure plate, a second fixed plate with a first upper pressure plate, a second fixed plate with a second upper pressure plate, a y-direction guide mechanism with a first set of springs, a y-direction guide mechanism with a second set of springs, an unequal area positive plate capacitive sensor with a first fixed electrode plate, an unequal area positive plate capacitive sensor with a second fixed electrode plate, an unequal area positive plate capacitive sensor with a first moving electrode plate, and an unequal area positive plate capacitive sensor with a second moving electrode plate; a z-direction guide mechanism including a vertical connecting plate, a first fixed plate, a second fixed plate, a first fixed plate with a first upper pressure plate, a first fixed plate with a second upper pressure plate, and a differential plate. First moving plate first upper pressure plate, first moving plate second upper pressure plate, second moving plate upper pressure plate, first moving plate, second moving plate, first moving plate lower pressure plate, second moving plate first lower pressure plate, second moving plate second lower pressure plate, first fixed plate first lower pressure plate, first fixed plate second lower pressure plate, second fixed plate first lower pressure plate, second fixed plate first upper pressure plate, second fixed plate second upper pressure plate, first set of springs of z-direction guide mechanism, second set of springs of z-direction guide mechanism, first fixed plate of unequal area positive plate capacitive sensor, second fixed plate of unequal area positive plate capacitive sensor, first moving plate of unequal area positive plate capacitive sensor, second moving plate of unequal area positive plate capacitive sensor.

2. The three-dimensional constant force scanning probe with 24 reeds according to claim 1, characterized in that: The upper end of the probe body is mounted on the guide rail of the coordinate measuring machine via a probe mounting base, and the lower end is connected to the stylus holder via a balance spring. The balance spring is used to counteract part of the weight of the stylus holder and the stylus. The x-axis guiding mechanism, y-axis guiding mechanism, and z-axis guiding mechanism are connected in series from top to bottom. The upper end of the x-axis guiding mechanism is fixed to the probe mounting base, and the lower end is connected to the stylus mounting base via a magnetic attraction structure. A trigger switch is installed between the fixed part and the moving part in the z-axis guiding mechanism. The trigger switch and the magnetic attraction structure together realize the anti-collision function of the probe. The differential capacitance sensor in each guiding mechanism and the two sets of orthogonally arranged unequal surface plate capacitance sensors are used to realize the redundant measurement of the 6 degrees of freedom of the guiding mechanism. The circuit processing module and the signal amplification module complete the data acquisition and preprocessing of the sensors inside each guiding mechanism.

3. The three-dimensional constant force scanning probe with 24 reeds according to claim 1, characterized in that: In the z-direction guiding mechanism, both the first and second sets of z-direction guiding springs bear the weight of the z-direction guiding mechanism in the tangential direction, and the two sets of springs are designed to have the same size. In the y-direction guiding mechanism, the first and second sets of y-direction guiding springs bear the weight of the z-direction guiding mechanism and the y-direction guiding mechanism in the tangential and axial directions, respectively, and the two sets of springs are designed to have different sizes. In the x-direction guiding mechanism, the first and second sets of x-direction guiding springs bear the weight of the z-direction guiding mechanism, the y-direction guiding mechanism, and the x-direction guiding mechanism in the axial and tangential directions, respectively, and the two sets of springs are designed to have different sizes.

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