Measuring device and machine tool error correction method using same

Abstract

The invention relates to a measuring device, which comprises a shell, a movable part, a correction ball and a sensing switch, the movable part is movably arranged on the shell. The correction ball is arranged at one end of the movable part and protrudes out of the shell. The sensing switch is arranged in the shell and is used for sensing the movement of the movable part relative to the shell; in addition, a machine tool error correction method using the measuring device is also disclosed.

Description

Technical Field

[0001] This invention relates to a measuring device and a method for correcting machine tool errors using the measuring device. Background Technology

[0002] Current technologies for correcting the rotating part errors of five-axis machine tools typically employ a contact sensing head from an R-test system or a non-contact sensing head from an LRT (Laser R-test) system, such as the sensing head 10 described in Chinese invention patent CN102371506A, in conjunction with a calibration ball to measure the length of a reference point. Then, based on the reference point length, error analysis is performed on each axis to calculate the axis's center position, thereby compensating for the rotational axis errors.

[0003] However, in the traditional process of measuring the length of a reference point, it is necessary to manually judge the measurement by touching the calibration ball with a dial indicator. This makes the measurement of the reference point length prone to errors and has the disadvantages of being complicated to operate and not being automated. Summary of the Invention

[0004] The present invention provides a measuring device and a machine tool error correction method using the measuring device, so as to reduce the error in measuring the length of the reference point and simplify and automate the measurement process of the reference point length.

[0005] An embodiment of the measuring device disclosed in this invention includes a housing, a movable member, a calibration ball, and a sensing switch. The movable member is movably disposed within the housing. The calibration ball is disposed at one end of the movable member and protrudes beyond the housing. The sensing switch is disposed within the housing and is used to sense the movement of the movable member relative to the housing.

[0006] Another embodiment of the present invention discloses a machine tool error correction method, which uses a measuring device in conjunction with an LRT sensing head, a computing unit, and a controller to perform error correction on a machine tool. The error correction method consists of a series of procedures, which are read by the computing unit and then executed in the following steps: the controller causes a spindle of the machine tool to push against a correction ball disposed on a movable part of the measuring device to obtain a first Z-axis coordinate value of the spindle and a first height value of the measuring device based on a sensing switch in the measuring device used to measure the movement of the movable part; the controller controls a rotating tool head of the machine tool to install the LRT sensing head onto the spindle and moves the spindle so that the correction ball of the measuring device is located at the center position of the LRT sensing head so that the offset error of the correction ball sensed by the LRT sensing head is 0, thereby obtaining a second Z-axis coordinate value of the spindle and a second height value of the measuring device; and the computing unit calculates a reference point length based on the first Z-axis coordinate value, the first height value, the second Z-axis coordinate value, and the second height value.

[0007] Another embodiment of the present invention discloses a machine tool error correction method, which uses a measuring device in conjunction with an LRT sensing head, a computing unit and a controller to perform error correction on a machine tool. The error correction method consists of a series of procedures, which are read by the computing unit and then executed in the following steps: using the measuring device and the computing unit to perform error analysis based on a reference point length to obtain an error value of the machine tool; and using the computing unit to correct a first rotating part and a second rotating part of the machine tool based on the error value of the machine tool.

[0008] According to the measuring device and machine tool error correction method disclosed in the above embodiments, a correction ball is disposed at one end of the moving part and protrudes outside the housing, and a sensing switch is used to sense the movement of the moving part relative to the housing. Therefore, the reference point length of the machine tool spindle can be measured using the measuring device and the LRT sensing head without the need for manual operation of a dial indicator. This not only reduces the error in measuring the reference point length but also simplifies and automates the reference point length measurement process. Furthermore, subsequent error correction of the machine tool based on the reference point length will be more accurate, and the error correction process can also be simplified and automated. Attached Figure Description

[0009] Figure 1 This is a plan view of an error correction system according to a first embodiment of the present invention.

[0010] Figure 2 for Figure 1 A plan view of the measuring device of the error correction system in the diagram.

[0011] Figures 3 to 7 For use Figure 1 The flowchart shows the error correction system and the error correction method of the LRT sensing head.

[0012] Figures 8 to 10 To present Figures 3 to 7 A planar schematic diagram of the error correction method in the diagram.

[0013] Figure 11 and Figure 12 This is a plan view of the measuring device according to a second embodiment of the present invention. Detailed Implementation

[0014] The following detailed description of the embodiments of the present invention outlines its features and advantages. This description is sufficient to enable anyone skilled in the art to understand the technical content of the embodiments of the present invention and to implement them accordingly. Furthermore, based on the disclosure, patent claims, and drawings in this specification, anyone skilled in the art can easily understand the relevant objectives and advantages of the present invention. The following embodiments further illustrate the viewpoints of the present invention, but are not intended to limit the scope of the invention in any way.

[0015] Please see Figure 1 and Figure 2 . Figure 1 This is a plan view of an error correction system according to a first embodiment of the present invention. Figure 2 for Figure 1 A plan view of the measuring device of the error correction system in the diagram.

[0016] In this embodiment, the error correction system 10 is used to correct the error of a machine tool 20, and mainly includes a measuring device 100 and a computing unit 200; the machine tool 20 is, for example, a five-axis machine tool, and is usually connected to a controller 300 to control the movement of each axis.

[0017] In this embodiment, the measuring device 100 includes a housing 110, a movable component 120, a calibration ball 130, a magnet 140, a sensing switch 150, a signal output port 160, and a light-emitting component 170. The housing 110 includes, for example, an internal space 111 and an opening 112 communicating with the internal space 111.

[0018] In this embodiment, the movable member 120 is slidably disposed on the housing 110, for example. Specifically, in this embodiment, the movable member 120 includes, for example, a slider portion 121 and a mounting protrusion 122. The mounting protrusion 122 protrudes from one side of the slider portion 121. The slider portion 121 is slidably disposed, for example, within the internal space 111 of the housing 110. The mounting protrusion 122 protrudes outward from the housing 110, for example, through an opening 112 in the housing 110.

[0019] The calibration ball 130 is disposed, for example, at the end of the mounting protrusion 122 away from the slider portion 121 and protrudes beyond the housing 110. The calibration ball 130 may be, for example, a circular standard ball or a circular lens, wherein the circular standard ball may be made of materials such as metal, plastic, or glass, and the circular lens may be made of light-transmitting materials such as glass or plastic. Furthermore, the calibration ball 130 may be disposed on the mounting protrusion 122 by means of adhesive bonding, but the invention is not limited thereto. In other embodiments, the calibration ball may also be disposed on the mounting protrusion in a fixed or movable manner by means of an additional connecting handle or other structure.

[0020] Magnets 140 are disposed in the housing 110 and used to attract the movable member 120. For example, the number of magnets 140 can be one or more. In this embodiment, the number of magnets 140 is, for example, two, evenly distributed in the housing 110, and respectively located opposite each other on both sides of the slider portion 121. A magnetic sensing component (not shown) is attached to the opposite part of the slider portion 121 so that the movable member 120 can be evenly attracted to the housing 110 by magnetic force. Therefore, the two magnets 140 can evenly attract the movable member 120. It should be noted that the present invention is not limited to the number of magnets 140. In other embodiments, the measuring device may also include a single magnet in a ring shape, or three or more magnets evenly distributed, as long as the magnets can evenly attract the movable member.

[0021] Furthermore, in this embodiment, by using a magnet 140 to attract the movable part 120, it can be ensured that the movable part 120 will not tilt when the measuring device 100 moves or shakes, thus ensuring the accuracy of subsequent measurement calibration.

[0022] The sensing switch 150 is disposed, for example, within the internal space 111 of the housing 110 and is used to sense the movement of the movable member 120 relative to the housing. In this embodiment, the sensing switch 150 is, for example, a contact switch, which is triggered upon contact with the movable member 120. It should be noted that the present invention is not limited to the form of a sensing switch. In other embodiments, the sensing switch may also be any position sensor capable of sensing the movement of the movable member relative to the housing, such as an optical ruler or a laser rangefinder.

[0023] The signal output port 160 is, for example, disposed in the housing 110 and electrically connected to the sensing switch 150 and the computing unit 200. It should be noted that, in this invention, the electrical connection between electronic components can be achieved via wired or wireless means.

[0024] The light-emitting component 170 is disposed in the housing 110 and exposed to the outside. The light-emitting component 170 is electrically connected to the signal output port 160. The light-emitting component 170 is used, for example, to emit light when the sensing switch 150 is triggered. The light-emitting component 170 is, for example, any light-emitting component such as a light-emitting diode. In other embodiments, the measuring device may not need to include a light-emitting component.

[0025] The computing unit 200 is electrically connected to the sensing switch 150 via the signal output port 160. The computing unit 200 may be, for example, an external processor or computer of the machine tool 20. The controller 300 is electrically connected to the computing unit 200 and is used to control the machine tool 20. The controller 300 may be, for example, an internal or external processor of the machine tool 20.

[0026] The following will be referred to Figure 1 and Figures 3 to 10 Instructions for use Figure 1Error correction method of error correction system 10 and LRT sensing head 30. Figures 3 to 7 For use Figure 1 The flowchart shows the error correction system and the error correction method of the LRT sensing head. Figures 8 to 10 To present Figures 3 to 7 A schematic diagram of the error correction method in the figure. In this embodiment, the error correction method using the error correction system 10 and the LRT sensing head 30 may include the following steps, which are executed by the computing unit 200 after the program stored in the computing unit 200 is read by the computing unit 200.

[0027] like Figure 1 and Figure 3 As shown, firstly, step S110 is performed, in which the measuring device 100 is placed on a first rotating member 21 of the machine tool 20. Next, step S120 is performed, for example, by moving a spindle 22 of the machine tool 20 using the controller 300, so that the nose 220 of the spindle 22 is adjacent to the measuring device 100 above it. Next, step S130 is performed, for example, by inputting reference data to the calculation unit 200. This reference data includes, for example, reference coordinate values ​​and reference height values. The reference coordinate values ​​include, for example, the X-axis reference coordinate value and the Y-axis reference coordinate value when the spindle 22 is adjacent to the measuring device 100. The reference height values ​​include, for example, a first height reference value relative to the first rotating member 21 when the movable member 120 is attracted by the magnet 140, and a second height reference value relative to the first rotating member 21 when the movable member 120 triggers the sensing switch 150.

[0028] like Figure 1 , Figure 4 and Figure 8As shown, step S140 is then performed, for example, by the controller 300 causing the nose 220 of the spindle 22 to push against the correction ball 130 disposed on the movable member 120, and for example, by the calculation unit 200 obtaining a first Z-axis coordinate value of the spindle 22 of the controller 300 and obtaining a first height value H1 of the measuring device 100 relative to the first rotating member 21 according to the sensing switch 150 in the measuring device 100 used to sense the movement of the movable member 120. In detail, in this embodiment, step 140 includes steps S141-S144 for example. In step S141, for example, by the controller 300 causing the spindle 22 to move along the Z-axis direction (negative Z-axis direction) at a first speed until the movable member 120 triggers the sensing switch 150. In step S142, for example, by the controller 300 causing the spindle 22 to move along the Z-axis direction (positive Z-axis direction) so that the movable member 120 stops triggering the sensing switch 150. In step S143, for example, the controller 300 causes the spindle 22 to move along the Z-axis direction (negative Z-axis direction) at a second speed lower than the first speed until the movable member 120 triggers the sensing switch 150. In step S144, for example, the calculation unit 200 obtains an X-axis coordinate value, a Y-axis coordinate value, and a first Z-axis coordinate value of the spindle 22, as well as a first height value H1 of the measuring device 100. For example, when the movable member 120 triggers the sensing switch 150 or stops triggering the sensing switch 150, the signal output port 160 sends a signal to the calculation unit 200 so that the calculation unit 200 can calculate the above values.

[0029] In this embodiment, the spindle 22 triggers the sensing switch 150 with a fast-then-slow movement. Therefore, it can be ensured that the spindle 22 is consistently positioned when triggering the sensing switch 150. In other embodiments, if the sensing switch is an optical ruler or encoder that can directly obtain spindle position information, the spindle does not need to use the aforementioned fast-then-slow movement method.

[0030] like Figure 5 , Figure 9 and Figure 10As shown, step S150 is then performed, for example, by controlling a rotating cutter head 23 via controller 300 to mount an LRT sensing head 30 onto the spindle 22, and by moving the spindle 22 via controller 300 to position the calibration ball 130 at the center of the LRT sensing head 30 so that the offset error of the calibration ball 130 sensed by the LRT sensing head 30 is 0. Then, for example, the calculation unit 200 obtains a second Z-axis coordinate value of the spindle 22 and a second height value H2 of the measuring device 100 relative to the first rotating member 21. Specifically, in this embodiment, step 150 includes steps S151-S155. In step S151, for example, by controlling the rotating cutter head 23 via controller 300 to mount the LRT sensing head 30 onto the spindle 22. In step S152, for example, by instructing the controller 300 via calculation unit 200 to move the spindle 22 according to the X-axis coordinate value, Y-axis coordinate value, and reference coordinate value. For example, if the X-axis coordinate value, Y-axis coordinate value, and reference coordinate value are X1, Y1, X', and Y' respectively, then step S152 involves moving the X-axis coordinate from X to X' and the Y-axis coordinate from Y1 to Y'. In step S153, for example, the controller 300 moves the main shaft 22 along the Z-axis direction to make the LRT sensing head 30 sense the offset error of the correction ball 130. In step S154, for example, the controller 300 moves the main shaft 22 along the X-axis, Y-axis, and Z-axis directions to make the correction ball 130 located at the center position of the LRT sensing head 30, so that the offset error of the correction ball 130 sensed by the LRT sensing head 30 is 0. In step S155, for example, the calculation unit 200 obtains the second Z-axis coordinate value and the second height value H2.

[0031] Next, step S160 is performed, for example, by the calculation unit 200 calculating a reference point length L based on the first Z-axis coordinate value, the first height value H1, the second Z-axis coordinate value, and the second height value H2. The reference point length L is, for example, the distance between the nose end 220 of the main shaft 22 and the center C of the correction ball 130. For example, the calculation unit 200 calculates the reference point length L using the following formula: L = (Z2 - Z1) - (H2 - H1) + r. In the above formula, Z1 is the first Z-axis coordinate value, Z2 is the second Z-axis coordinate value, H1 is the first height value, H2 is the second height value, and r is the radius r of the correction ball 130. The steps S110, S120, S130, S140, S141-S144, S150, S151-S155, and S160 for obtaining the reference point length L can be repeated multiple times to reduce errors.

[0032] Next, please refer to Figure 6 and Figure 9For example, the same measuring device 100 and calculation unit 200 can be used to perform step S170, and error analysis is performed based on the reference point length L to obtain the error value of the machine tool 20. In this embodiment, step S170 includes steps S171-S173 for example. In step S171, for example, the measuring device 100 performs the error analysis process of the first rotating part 21, and the calculation unit 200 performs error calculation based on the reference point length L to obtain the first error value and the second error value of the first rotating part 21. In step S172, for example, the measuring device 100 performs the error analysis process of the second rotating part 24, and the calculation unit 200 performs error calculation based on the reference point length L to obtain the third error value and the fourth error value of the second rotating part 24. In step S173, for example, the measuring device 100 performs the error weight analysis process of the machine tool 20, and the calculation unit 200 calculates the error weight value based on the first error value, the second error value, the third error value, the fourth error value, the command of the machine tool 20, the feedback, and the deviation value measured by the LRT sensing head. Furthermore, since the same measuring device 100 is used for step S170, the calibration ball 130 of the measuring device 100 can be used to replace the calibration ball dedicated to the LRT sensing head 30, thereby reducing errors caused by device disassembly and assembly.

[0033] Please refer to the following: Figure 7 and Figure 9 Step S180 is performed, in which the calculation unit 200 corrects the first rotating component 21 and the second rotating component 24 of the machine tool 20 according to the error value (such as the error weight value). In this embodiment, step S180 includes, for example, steps S181-S182. In step S181, for example, the calculation unit 200 determines whether the error weight value exceeds a critical value. If the error weight value exceeds the critical value, then step S182 is performed, for example, in which the calculation unit 200 corrects the position of the first rotating component 21 and the second rotating component 24 according to the first error value, the second error value, the third error value, and the fourth error value.

[0034] With the assistance of the measuring device 100 and the LRT sensing head 30, the reference point length L of the spindle 22 of the machine tool 20 can be measured without the need for manual operation of the dial indicator. This not only reduces the error in measuring the reference point length L, but also simplifies and automates the measurement process.

[0035] Furthermore, by employing a sensing switch 150 in the form of a contact switch, the measuring device 100 does not require an additional decoder, thus simplifying the structure of the measuring device 100 and reducing its manufacturing cost.

[0036] Other embodiments will be listed below for illustration. It must be noted that the following embodiments use the component reference numerals and some content from the foregoing embodiments, with the same reference numerals representing the same or similar components, and descriptions of identical technical content omitted. For explanations of the omitted parts, please refer to the foregoing embodiments; these will not be repeated in the following embodiments.

[0037] This invention is not limited to the arrangement of moving parts within the housing. Please refer to [link / reference]. Figure 11 and Figure 12 . Figure 11 and Figure 12 This is a plan view of the measuring device according to a second embodiment of the present invention.

[0038] The difference between the measuring device 100a of this embodiment and the measuring device 100 of the first embodiment lies only in the manner in which the movable member 120a is disposed on the housing 110a. Specifically, in this embodiment, the movable member 120a includes, for example, a first rod portion 121a and a second rod portion 122a connected to each other. The extending directions of the first rod portion 121a and the second rod portion 122a are, for example, perpendicular to each other. The first rod portion 121a is pivotally connected to the housing 110a. The end of the first rod portion 121a away from the second rod portion 122a is used to be attracted by a magnet 140 and to trigger a sensing switch 150 (e.g., ...). Figure 12 (As shown). The correction ball 130 is located at the end of the second rod 122a away from the first rod 121a.

[0039] According to the measuring device and machine tool error correction method disclosed in the above embodiments, a correction ball is disposed at one end of the moving part and protrudes outside the housing, and a sensing switch is used to sense the movement of the moving part relative to the housing. Therefore, the reference point length of the machine tool spindle can be measured using the measuring device and the LRT sensing head without the need for manual operation of a dial indicator. This not only reduces the error in measuring the reference point length but also simplifies and automates the reference point length measurement process. Furthermore, subsequent error correction of the machine tool based on the reference point length will be more accurate, and the error correction process can also be simplified and automated.

[0040] [Symbol Explanation]

[0041] 10: Error Correction System

[0042] 100, 100a: Measuring device

[0043] 110, 110a: Shell

[0044] 111: Interior Space

[0045] 112: Opening

[0046] 120, 120a: Active parts

[0047] 121: Slider section

[0048] 122: Install the protrusion

[0049] 121a: First part of the rod

[0050] 122a: Second rod section

[0051] 130: Correction ball

[0052] 140: Magnet

[0053] 150: Sensor switch

[0054] 160: Signal output port

[0055] 170: Light-emitting components

[0056] 200: Computing Unit

[0057] 300: Controller

[0058] 20: Machine Tools

[0059] 21: First rotating component

[0060] 22: Spindle

[0061] 220: Nasal tip

[0062] 23: Rotary cutter head

[0063] 24: Second rotating component

[0064] 30: LRT sensor head

[0065] S110, S120, S130, S140, S141-S144, S150, S151-S155, S160, S170, S171-S173, S180, S181-S182: Steps

[0066] H1: First height value

[0067] H2: Second height value

[0068] C: Center

[0069] r: radius

Claims

1. A measuring device, comprising: A shell with an internal space; A movable component is movably disposed within the internal space; A correction ball, disposed at one end of the movable member and protruding outside the housing; and A sensing switch is disposed in the internal space and used to sense the movement of the moving part relative to the housing.

2. The measuring device as claimed in claim 1, wherein the movable member is slidably disposed on the housing.

3. The measuring device as claimed in claim 1 further includes at least one magnet, the at least one magnet being disposed in the internal space and used to attract the movable part.

4. The measuring device as claimed in claim 1, wherein the sensing switch is a contact switch.

5. The measuring device as claimed in claim 1, wherein the movable element is pivotally connected to the housing.

6. The measuring device as claimed in claim 1 further includes a signal output port, the signal output port being disposed on the housing and electrically connected to the sensing switch.

7. The measuring device as claimed in claim 6 further includes a light-emitting component, the light-emitting component being disposed outside the housing, and the light-emitting component being electrically connected to the signal output unit.

8. A machine tool error correction method, comprising using the measuring device as described in claim 1, in conjunction with an LRT sensing head, a computing unit, and a controller, to perform error correction on a machine tool, wherein the error correction method comprises a series of procedures, which are read by the computing unit and then executed in the following steps: The controller causes a spindle of the machine tool to push against the calibration ball disposed on the movable part of the measuring device, thereby obtaining a first Z-axis coordinate value of the spindle and obtaining a first height value of the measuring device according to the sensing switch in the measuring device used to measure the movement of the movable part; The controller controls a rotating cutter head of the machine tool to install the LRT sensing head onto the spindle, and moves the spindle so that the calibration ball of the measuring device is located at the center of the LRT sensing head so that the offset error of the calibration ball sensed by the LRT sensing head is 0, thereby obtaining a second Z-axis coordinate value of the spindle and a second height value of the measuring device; as well as The calculation unit calculates the length of a reference point based on the first Z-axis coordinate value, the first height value, the second Z-axis coordinate value, and the second height value.

9. The machine tool error correction method as described in claim 8, wherein the step of causing the spindle to push against the correction ball via the controller, and obtaining the first Z-axis coordinate value and the first height value according to the sensing switch, comprises: The controller causes the spindle to move along the Z-axis at a first speed until the moving part triggers the sensing switch. The controller causes the spindle to move along the Z-axis, thereby stopping the moving part from triggering the sensing switch. The controller causes the spindle to move along the Z-axis at a second speed lower than the first speed until the moving part triggers the sensing switch. as well as The calculation unit obtains the X-axis coordinate value, Y-axis coordinate value, and first Z-axis coordinate value of the main shaft, as well as the first height value of the measuring device.

10. The machine tool error correction method as described in claim 8, wherein the step of controlling the rotating cutter head of the machine tool to mount the LRT sensing head to the spindle via the controller, and moving the spindle so that the correction ball is located at the center position of the LRT sensing head so that the offset error of the correction ball sensed by the LRT sensing head is 0, thereby obtaining the second Z-axis coordinate value and the second height value, comprises: The controller controls the rotating cutter head to install the LRT sensor head onto the spindle; The calculation unit instructs the controller to move the main axis based on the X-axis coordinate value, the Y-axis coordinate value, and a reference coordinate value. The LRT sensing head senses the offset error of the correction ball by moving the main shaft along the Z-axis direction using the controller. The controller moves the main shaft along the X, Y, and Z axes to position the calibration ball at the center of the LRT sensing head; and The calculation unit obtains the second Z-axis coordinate value and the second height value.

11. A machine tool error correction method, comprising using the measuring device as described in claim 1, coupled with an LRT sensing head, a computing unit, and a controller, to perform error correction on a machine tool, wherein the error correction method comprises a series of procedures, which are read by the computing unit and then executed in the following steps: Using the measuring device and the computing unit, an error value of the machine tool is obtained by performing error analysis based on the length of a reference point; and The calculation unit corrects a first rotating component and a second rotating component of the machine tool based on the error value of the machine tool.

12. The machine tool error correction method as described in claim 11, wherein the step of obtaining the error value of the machine tool by performing error analysis based on the reference point length using the measuring device and the calculation unit comprises: The measuring device performs the error analysis process of the first rotating component and the calculation unit performs error calculation based on the length of the reference point to obtain a first error value and a second error value of the first rotating component. The measuring device performs an error analysis process on the second rotating component, and the calculation unit calculates the error based on the length of the reference point to obtain a third error value and a fourth error value for the second rotating component; and The measuring device executes the error weight analysis process of the machine tool and calculates an error weight value based on the first error value, the second error value, the third error value, the fourth error value, the machine tool's command, feedback, and the deviation value measured by the LRT sensing head through the calculation unit.

13. The machine tool error correction method as described in claim 11, wherein the step of correcting the first rotating component and the second rotating component of the machine tool by the calculation unit according to the error value of the machine tool includes: The calculation unit determines whether the error weight value exceeds a critical value. If the error weight value exceeds the critical value, the calculation unit corrects the positions of the first rotating component and the second rotating component based on the first error value, the second error value, the third error value, and the fourth error value.

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