JPH03100416A - Probe for detecting position of three-dimensional free curved surface and work end part structure for working or the like of three-dimensional free curved surface - Google Patents

Abstract

PURPOSE:To obtain the position detecting probe which can measure easily X, Y and Z coordinates of the curved surface and can be handled easily by constituting so that a relative position of a detection point and a base part is not varied even if the attitude of the detection part is varied in accordance with the curved surface of the surface to be detected. CONSTITUTION:A base part 1 is attached to an orthogonal triaxial three-dimensional measuring machine. Subsequently, X, Y and Z of its measuring machine are moved so that the tip of a detecting part 5 comes into contact with a detection point A1 of the surface to be measured. Simultaneously, the base part 1 is turned around an axis so that the axis of the detecting part 5 coincides with the normal direction of the detection point, and also, a first link 2 is turned around the axis. Reading of X, Y and Z of the measuring machine in such a case is a measured value of the detection point A1, and also, reading of a rotation angle of a rotary dial plate 7 shows the normal direction of the detection point A1, respectively. In the same way, each point on the surface to be measured is measured successively. As a result, each link 2 cannot further rotate to the right. Therefore, by rotating the base part 1 by 180 deg., each point of the surface to be measured can be measured. Also, in the work end part structure, a working part or a processing part is placed instead of the detecting part 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a probe that can extremely easily measure a complete three-dimensional free-form surface, and a probe that can perform cutting, grinding, electrical discharge machining, and even a three-dimensional free-form surface. This invention relates to a working end structure that can perform cleaning work, painting work, three-dimensional drawing, three-dimensional cutting, etc.

[Traditional technique]

Demand for precise three-dimensional measurement and three-dimensional processing has been increasing recently. For example, household appliances.

There are many things that require three-dimensional free-form surfaces, such as automobile bodies, aircraft and ship propellers, and turbine blades. Therefore, there is a need for something that can easily and accurately measure and process the three-dimensional curved surface. The name of a conventional three-dimensional measuring device tends to make it seem like it can measure all three-dimensional surface shapes. However, in general, arbitrary two-dimensional measurements can only be made by specifying the XY plane, 72 plane, and ZX plane among the three dimensions, and measurement of three-dimensional free-form surfaces is practically impossible with well-known three-dimensional measuring machines. .

To measure a free-form surface, a probe with the shape most suitable for the curved surface is brought into contact with each part of the curved surface at the optimal angle (posture) of the probe axis, and the probe is moved or swept along the characteristic line 3 contour line or streamline. Ideally, it would be possible to trace the object and detect its three-dimensional coordinates and normal vector.

Conventionally, a five-axis control measuring machine shown in FIG. 13 has been proposed for this purpose. This 5-axis control measuring machine has X, Y, Z
It has each rectilinear axis (three-dimensional orthogonal rectilinear axis), one rotational axis among the three axes, and a rotational axis perpendicular to the rotational axis. That is, the upper end of the probe is attached to the lower end of the Z axis of a coordinate measuring machine 25 having linear axes of X, Y, and Z. This probe has a pulse motor 16 that rotates the probe body around the Z-axis and a pulse motor 17 that rotates the detection section 5 around an axis perpendicular to the Z-axis. The detection unit 5 has a distal end portion that is extendable and retractable, and has a differential transformer in the extendable cylinder portion. Note that the rotation angle around the Z-axis by the pulse motor 16 is output as a detection signal by the potentiometer 26, and the rotation angle by the other pulse motor 17 is output by the potentiometer 27, and these are input to a control device (not shown).

At the same time, the expansion and contraction of the detection section 5 is inputted to the control device by an output signal from the differential transformer 28. In order to measure a three-dimensional free-form surface using such a five-axis control measuring machine, a detection unit 5 is placed on the surface of the surface to be measured 11 as shown in FIG.
Touch the tips of the The normal direction of this contact point and the detection unit 5
The pulse motor 16 and the pulse motor 17 are rotated so that the axes of the pulse motor 16 and the pulse motor 17 coincide with each other. Thereby, the three-dimensional coordinates and normal vector at the contact point on the surface to be measured 11 can be obtained.

[Problem to be solved]

However, such a five-axis measuring machine needs to be automatically controlled by a computer using an extremely complicated program. This is because, when considering the approach of a probe to a measurement point on a free-form surface using the three-dimensional measuring machine 25 that moves in three orthogonal axes of X, Y, and Z rectilinear axes, the following will occur. First, in order to apply the probe to the curved surface at the optimum angle of the probe axis, it is necessary to rotate the two rotation axes mentioned above. Then, you will have to swing the base of the probe mounting part.
The coordinates of the tip of the probe are thick (changed. Then, the probe will deviate from the target measurement point.Then, approach the measurement point again with the probe.Next, the coordinates of the measurement point and the probe axis that touches it) It is necessary to consider whether the angle of This causes the head to deviate greatly from the axis, causing the X, Y, and
It is not possible to specify the reading of each coordinate of Z by the three-dimensional measuring machine 25, and the coordinate position of the measurement point can only be determined by performing complex and advanced coordinate calculations. Even if it were possible to measure one point on a curved surface, it would be difficult to continuously measure an infinite number of such measurement points using manual control. Therefore, a 5-axis CNC three-dimensional measuring machine automatically controlled by a computer must be used. With such a measuring machine, it is extremely troublesome to complete a measuring program for an arbitrary curved surface. Moreover, such a measuring device inevitably has a complicated structure and is expensive. Therefore, such measuring instruments are not widely used at present.

Therefore, the present inventor devised a probe with a mechanism that eliminates the need for these troublesome operations from a 5-axis control measuring machine, and developed a working end section for machining three-dimensional free-form surfaces using the main part of this probe mechanism. The purpose is to provide structure.

[Means to solve the problem]

In the probe for detecting the position of a three-dimensional free-form surface according to the present invention, a base portion 1 is mounted rotatably around an axis N. At least two pairs of first links 2.2 and second links 3 form a parallelogram with straight lines connecting the respective pivot points.
, 3 is provided. And that-
A pair of first links 2, 2 are each pivotally connected to the base 1, so that a pair of first orthogonal axes perpendicular to the axis N, L2
It is configured to rotate around the Furthermore, the detection unit 5 is pivotally connected to the pair of second links 3.3 of the parallel link mechanism 4. At this time, the second links 3, 3 are aligned with the first orthogonal axis,
A pair of second orthogonal axes L3 parallel to L2. It is pivoted so as to rotate around L4, and its detection point A is an extension of the axis N,
A virtual plane R including a pair of second orthogonal axes, L, and a pair of first orthogonal axes.

It is located on the intersection with the virtual plane S that includes L2.

Next, the working end structure for machining a three-dimensional free-form surface according to the present invention is such that a processing section 6 or a working section is arranged in place of the detecting section 5 of the probe.

The processing end or working end is located on the intersection of N, R, and S.

[For production]

In the probe of the present invention, the detection point A of the detection section 5 is always at a constant point with respect to the base 1 regardless of changes in the posture of the detection section 5. Therefore, the x, y, and z coordinates of the detection point A of the probe can be read by a conventional orthogonal three-axis three-dimensional measuring machine.

That is, the coordinate values of the tip of the probe can be directly read using a generally widely used three-dimensional measuring machine having x, y, and z linear axes. The reason why this detection point A does not move relative to the base 1 regardless of the attitude of the detection unit 5 is as follows. This is because the detection point A of this probe is on the intersection of the axis N, plane R, and plane S in FIG. This is because the position of the detection point A is the same even if the detection point A is the same. In addition, in FIG. 1, the plane R and the axis N in FIG. 9 coincide. Here, the axis N is the axis of rotation of the base 1, the plane R is the plane formed by the axes L+-Lz, and the plane S is the axis L3. This is a plane formed by L4.

Further, in the working end structure of the present invention, the processing part 6 or the working part is arranged in place of the detecting part 5, and the working end is located at the detecting point, so that the control becomes extremely easy.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

Fig. 1 is a front view of the first embodiment of the present invention, Fig. 2 is a side view of the same, and Figs. 3 to 6 are rear views of the probe of the same embodiment, showing the state in which it is used. It is an explanatory diagram.

Further, FIG. 7 shows a second embodiment of the probe of the present invention, FIG. 8(a) is a front view showing an embodiment of the processing part 6 of the working end structure of the present invention, and FIG. 8(b) is a Same side view, Figure 8 (C)
is an explanatory diagram showing the usage state. Further, FIG. 9 is an explanatory diagram showing a third embodiment of the probe of the present invention, FIG. 10 is a front view of a fourth embodiment of the probe of the present invention, FIG. 11 is a perspective view thereof, and FIG. is the same side view.

The probe according to the first embodiment of the present invention has a base portion 1, a parallel link mechanism 4, and a detection portion 5, as shown in FIGS. 1 and 2. A flange portion is formed at one end of the base portion 1, and a rotating shaft 9 is fixed at the center of the flange portion. Further, a rotary scale plate 8 is fixed to the flange portion of the base l, and is mounted so that its center coincides with the axis N of the rotary shaft 9. Next, the parallel link mechanism 4 pivots a pair of first links 2.2 and a second link 3.3, which are positioned parallel to each other, at the middle and one end of each link. And a pair of first links 2
, 2 are pivoted to the base 1 along the axis L3. Pivot to L4. At this time, the detection point A at the tip of the detection unit 5 is made to have the following relationship.

That is, the pivot axis L3. The plane S created by L4 and the axis line,
, L, and the detection point A is located at the intersection of the plane R and the axis N of the rotating shaft 9. Further, in this embodiment, the rotary scale plate 7 is fixed to the 11th link 2 via a fixing screw 10, and the rotary scale plate 7 is configured to rotate together with the first link 2 about the axis. Also, each first link 2. The pivot portion of the second link 3 is deviated from the centerline position passing through the center of the width of each link and protrudes laterally;
The whole is E-shaped. As shown in FIG. 2, a pair of first links 2.2 and a pair of second links 3 are connected to the base 1.
, 3 are arranged sequentially in the thickness direction of the base 1, respectively. Note that these first links 2. The reason why the second link 3 is formed into an E-shape as shown in FIG. 1 is to prevent the pivot points of each link from interfering with each other when each link is rotated. That is, this is to prevent the pivot points of each link from interfering with each other even if the state of each link is changed from the state shown in FIG. 5 to the state shown in FIG. 6 when viewed from the back side. Conversely, when the pivot point of each link is located on the center line of that link, the first links 2, 2 and the second links 3, 3 interfere and collide with each other, as shown in FIG. The pivot points cannot be placed in a straight line. Therefore,
The detection unit 5 cannot be arranged in the direction shown in the figure. This is because the first link 2, 2 and the second link in FIG.
This is because the links 3, 3 are arranged at the same level in the thickness direction with respect to the base 1, so the pivot points of both links cannot be overlapped.

Next, in order to measure an arbitrary point on the surface to be measured 11 forming a three-dimensional curved surface using the probe thus constructed, the following procedure may be performed.

First, in FIG. 3, the base l is attached to an orthogonal three-axis coordinate measuring machine (not shown). Then, move the orthogonal three-axis coordinate measuring machine in x, y, and z, so that the tip of the detection unit 5 is on the surface to be measured 11.
so that it comes into contact with detection point A. At the same time, the base 1
is rotated around the axis N, and the first link 2 is rotated around the axis N. At this time, the X, Y, and Z readings of the orthogonal three-axis three-dimensional measuring machine are the measurement values at the detection point A, and the rotation angle readings of the rotary scale plate 7°8 are the normal direction of the detection point A1. represents. Similarly, each point A on the surface to be measured 11
2. A3° and A4 are measured sequentially as shown in FIGS. 4 to 6.

Then, from the state shown in FIG. 6, each link cannot rotate any further to the right. Therefore, by rotating the base 1 by 180', it is possible to measure each point on the surface to be measured 11 located on the right side in the figure. If it is only necessary to measure the position using a probe with a sharp tip or a small pole probe (when measuring the normal vector is not required), the rotation angle setting of the base 1 and the rotation angle setting of the first link 2 can be used. There is almost no three-dimensional measurement error. However, for a probe with a large spherical surface, it is necessary to ensure that the probe axis is correctly normal to the curved surface.

10 to 12 show a preferred embodiment in which a dial gauge is used at the tip of the probe. In this embodiment, the detection unit 5 is supported between a pair of parallel link mechanisms 4.4,
The base 1 is formed into a gate shape, and the first links 2 of a parallel link mechanism 4 are pivotally connected to both legs of the base 1, respectively. Then, the rotation angle of the first link 2 is outputted by the encoder 22. and a gear 3 that meshes the rotation angle of the base 1 with its upper end.
1. It is output by the encoder 22 via the gear 32.

The entire probe is attached to an orthogonal three-axis coordinate measuring machine (not shown) via the attachment member 21. In order to perform measurement using the dial gauge in the detecting section 5 in this way, the following procedure may be performed. First, the brake 19 is brought into contact with the peripheral edge of the rotary scale plate 8 fixed to the rotary shaft 9, and the first
The tip of the brake 18 is brought into contact with the peripheral edge of the rotary scale plate 7 that rotates together with the link 2. Next, the tip of the detection section 5 is brought into contact with the target measurement point.

At this time, the dial gauge is positioned so that its axis is approximately in the normal direction of the measurement point. Then, the base 1 is slightly rotated forward and backward. Then, if the axis of the dial gauge does not exactly match the normal direction of the surface to be measured, the reading of the dial gauge increases due to the rotation. The theoretical analysis is based on Japanese Patent Publication No. 112 related to another application filed by the present inventor.
I give it to No. 326. Therefore, the rotation angle of the base 1 is fixed by the brake 19 when the dial gauge reading is minimum. Next, each link is slightly rotated around the axis L, and the rotary scale plate 7 is fixed via the brake 18 when the dial gauge reading is the minimum in the same manner as described above. Therefore, the three-dimensional coordinates and rotation angles of the base 1 and the first link 2 are read. The rotation angle of the base 1 can be read by the rotary scale plate 8, and can also be converted into an electrical signal via the encoder 22. Similarly, the rotation angle of the first link 2 can be read from the angle scale of the rotary scale plate 7, and it can be read by the encoder 2.
can be converted into an electrical signal via 2.

[Examples of odd forms]

In FIGS. 10 to 12, a touch signal probe or a cutting cutter may be used instead of the dial gauge 23. To perform measurements using a touch signal probe, proceed as follows.

First, the contact portion of the tip of the probe is brought close to the target measurement point so that its axis is approximately normal to the curved surface. Then, the base 1 is rotated forward and reverse around the axis N, and the rotation angle of the base 1 is fixed at the average angle of the angle at which the probe makes contact in the forward rotation and the angle at which the probe contacts in the reverse rotation. Next, the rotation angle of the parallel link mechanism 4 that rotates around the axis and around L2 is similarly fixed at the average angle. Then, it is sufficient to bring the probe into contact with the target measurement point for the first time and read the three-dimensional coordinates of the orthogonal three-dimensional measuring machine, the angle around the N axis, and the angle around the axis.

Further, in FIG. 11, a cutter with a drive motor can be installed in place of the detection section 5. In this case, the position of three orthogonal axes is controlled according to a predetermined work procedure, and the base 1 is rotated around the axis N via the pulse motors 16 and 17 shown in FIG. While rotating the first link 2 around the axis L1, it is possible to cut the workpiece by holding the cutting edge of the processing section at an optimal angle.

Next, FIG. 7 shows another embodiment of the present invention, and this embodiment differs from the first embodiment in that each pair of first links 2
,2. Among the second links 3, 3, one link 2.3 is formed to have approximately half the length of the other, and the pair of first links 2, 2 are attached to a pivot joint portion that is pivoted to the base 1. A pair of gears are provided, and the gears are meshed with each other via an idler.

Next, FIG. 8(a) shows another embodiment in which a processing section 6 is used in place of the detection section 5 of the previous embodiment, and the axis of the rotary blade 36 is the same as the axis to which the processing section 6 is pivoted. A plane S containing ,L
This is an example of eccentricity. The cutting work point B of the rotary blade 36 is located at the intersection of the plane S and the axis N. Moreover, FIG. 8('b) is a side view of FIG. 8(a). Also, in measurement, in a narrow space where the probe axis cannot approach a curved surface from the normal direction, it is preferable to use a side contact of a bullet-shaped probe as shown in FIG. 8(a). Such measurements are also necessary for compatibility of measurement and processing data. In addition, the base 1
The rotation axis N is not necessarily Z when installed on various machine tools, etc.
It does not have to be located on an axis; it can also be placed on a horizontal X or Y axis.

Next, FIG. 9 shows another embodiment of the probe of the present invention,
This embodiment differs from the first embodiment in that the axis N is a pair of axes L1. It does not exist on the plane R that includes L2.

Next, in the embodiment shown in FIG. 11, the second links 3.3 located at the upper ends of the pair of parallel link mechanisms 4, 4 may be connected. The connection beam may be suspended vertically to support the weight of each link and the detection unit 5.

Next, in each embodiment, each pivot portion of the parallel link mechanism 4 is formed of a pin with flanges at both ends as shown in FIG. It can also be pivoted by. Furthermore, since it is difficult to attach a loosening preventer to a small item, one end of the pin can be caulked to integrate the pin during assembly.

[Example of application]

Although the present invention has been described in the above embodiments in terms of the case where it is used as a probe and the case where it is used in cutting processing, the detection section 5 of this structure
Instead of , you can install: That is,
Cutting tools, grinding tools.

Polishing tools, processing electrodes, laser guns, water jet guns, welding torches, spot welding electrodes.

Install spray guns, brushes, brushes, pencils, pens, knives, electric scissors, and sewing machines. As a result, it can be used for machining, artistic carving, cleaning work, painting work, three-dimensional drafting, three-dimensional cutting, etc.

Furthermore, the machine hand may be attached and used as a working robot.

In addition, CAD of three-dimensional free-form surfaces (Computer A
It can be used as a three-dimensional coordinate input pen in IDE Design. In other words, if you hold the detection unit 5 in your hand like a pen and draw a three-dimensional diagram in a three-dimensional space, the shape can roughly be drawn by hand on a computer. If a model already exists, it is sufficient to trace it using the detection unit 5 along the characteristic lines and streamlines of the curved surface like a pen. Then, three-dimensional coordinates including path information of probes, cutting tools, etc. can be input.

〔Effect of the invention〕

1) In the probe of the present invention, even if the attitude of the detection unit 5 changes depending on the curved surface of the detection target surface, the relative position between the detection point A and the base 1 does not change. This is because the detection point A exists on the intersection of the plane formed by the beams, L, Lff+L4, and the axis N of the base 1. Therefore, no matter what attitude the detection unit 5 has, it is always detected relative to the base l. Point A becomes a specific point. Therefore, when this probe is attached to an orthogonal three-axis type three-dimensional measuring machine, the X, Y, and Z coordinates of the three-dimensional free-form surface can be extremely easily measured from the readings of the measuring machine, and the rotation angle of the first link 2 can also be measured. The normal direction of the detection point A can be determined from the rotation angle of the base l. Therefore, it is possible to provide a position detection probe that is extremely easy to handle.

2) Furthermore, the working end structure for machining a three-dimensional free-form surface of the present invention is provided with a machining section 6 etc. in place of the detection section 5, and the data of measurement and machining are compatible. , it is possible to create a measurement program and a Canadian program at the same time. This allows processing and other operations to be performed with ease of control.

[Brief explanation of drawings]

FIG. 1 is a front view showing a probe according to a first embodiment of the present invention;
Figure 1 (a) is a schematic cross-sectional view taken along arrow r- in Figure 1, Figure 2 is a side view of Figure 1, and Figures 3 to 6 are three-dimensional free-form surfaces from this probe. A, -A4 on the surface to be measured 11
FIG. 7 is a front view of another embodiment of the present invention, and FIG. 8(a) is an explanatory diagram when measuring each point of the invention. FIG. 8(b) is a front view showing the embodiment, FIG. 8(b) is a side view thereof, FIG. 8(c) is an explanatory diagram of the cutting process, FIG. 9 is a front view showing another embodiment of the present invention, and FIG. 10 to 12 show other embodiments of the probe of the present invention, in which FIG. 10 is a front view showing a state in which a dial gauge is attached to the detection part 5, FIG. 11 is a perspective view thereof, and FIG. 12 is a FIG. 13 is a side view of the same, FIG. 13 is a perspective view showing an example of a conventional three-dimensional free-form surface position detection probe, and FIG. 14 is an explanatory view showing its usage state. 1... Base 2... First link 3... Second
Link 4... Parallel link mechanism 5... Detection section
6... Processing part A... detection point L+, Lz... first orthogonal axis L
s, L4...Second orthogonal axis line, ~L8...Axis line 7.8...Rotary scale plate 9...Rotary axis 10...Fixing screw 11...Measurement surface 12.24. ...Spacers 13, 14...
Bearing ball 15...Retainer 16.17...Pulse motor 18, 19...Brake 20...Arm 21...Mounting member 22...
Encoder 23...Dial gauge 25...Coordinate measuring machine 26.27...Potentiometer 28...Differential transformer

Claims (1)

[Claims] 1) A base (
1), and at least two pairs of first links (2) (2
) and a second link (3) (3), the axis (N)
A parallel link mechanism (4) in which the pair of first links (2) (2) are respectively pivotally connected to the base (1) so as to rotate around a pair of first orthogonal axes (L_1, L_2) perpendicular to the ), and a pair of said first orthogonal axes (
A pair of second orthogonal axes (L_3) parallel to L_1, L_2)
, L_4), respectively, and the detection point (A) is connected to the extension line of the axis (N) and the pair of second Orthogonal axis (L_3
, L_4) and a pair of said first
Virtual plane (S) containing orthogonal axes (L_1, L_2)
A probe for detecting the position of a three-dimensional free-form surface, comprising: a detection part (5) located on the intersection with the three-dimensional free-form surface. 2) The base (which is attached rotatably around the axis (N)
1), and at least two pairs of first links (2) (2
) and a second link (3) (3), the axis (N)
A parallel link mechanism (4) in which the pair of first links (2) (2) are respectively pivotally connected to the base (1) so as to rotate around a pair of first orthogonal axes (L_1, L_2) perpendicular to the ), and a pair of said first orthogonal axes (
A pair of second orthogonal axes (L_3) parallel to L_1, L_2)
, L_4), and the machining end or working end thereof is connected to the extension line of the axis (N) Orthogonal axis (L
_3, L_4) and a virtual plane (R) including the pair of first orthogonal axes (L_1, L_2).
A working end structure for machining a three-dimensional free-form surface, etc., comprising a machining part (6) or a working part located on the intersection with S).