JP2009204463A - Wire type three-dimensional coordinate measuring machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire type three-dimensional coordinate measuring machine for measuring the flatness or the shape of a measuring object by a simple structure. <P>SOLUTION: This machine is described as follows: a horizontal arm 3 wherein a linear scale 4 is fitted on an upper part of a stand 1 is provided; a wire 8 is connected to the tip of a read head 30 to be moved horizontally on the linear scale 4; a wire guide instrument 7 comprising a rotary guide 5 through which the wire 8 pulled out from the linear scale 4 is passed and an angle guide 6 connected thereto rotatably is provided on the tip of the horizontal arm 3; a hollow encoder 33 for detecting a rotation angle of the angle guide 6 is provided on the rotary guide 5; an encoder 42 for detecting a bending angle of the wire 8 is provided on the shaft 30 for connecting rotatably the rotary guide 5 to the angle guide 6; a coordinate computing unit for operating the coordinate of a tip piece 10 is provided; and thereby the position coordinate of the tip piece 10 in contact with the measuring object 12 is operated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an inexpensive wire type three-dimensional coordinate measuring machine having a simple structure.

In general, when manufacturing products in the wood industry, sheet metal industry, can manufacturing industry, etc., the length and width, height, flatness, etc. are measured using a tape measure or vernier caliper, but shape accuracy is required. There is a problem that the product cannot measure accurately. For this reason, if a large three-dimensional coordinate measuring machine is used, it is possible to measure with high accuracy, but it is expensive and requires a wide installation place, which is difficult to introduce in small and medium-sized enterprises.

In addition, the conventional three-dimensional coordinate measuring machine combines two movable frames orthogonally, attaches a drum with a wire wound around one movable frame, and passes the wire drawn from this through the other movable frame. The tip of the wire (moving body) is attached to the tip of the wire, the encoder is attached to the rotating shaft of the drum and the rotating shaft of both movable frames, and the rotational angle of the drum and the rotational angle of the two movable frames orthogonal to each other Is detected by an encoder to measure the position coordinates of the tip terminal brought into contact with the object to be measured (Patent Document 1).

However, in this apparatus, since the wire connected to the tip terminal is wound around the drum, the number of revolutions of the drum and the wire drawing length are not proportional to each other due to the winding position or the lap winding, and the wire is connected to the other side. Since the wire is drawn through the ring of the movable frame, a gap is formed between the wire and the wire, and an accurate angle change cannot be detected, resulting in poor detection accuracy.
JP-A-5-296757

The present invention improves the above problems, and provides a wire type three-dimensional coordinate measuring machine that has a simple structure, high measurement accuracy, and is small and inexpensive.

In the wire type three-dimensional coordinate measuring machine according to claim 1 of the present invention, a horizontal arm is attached to an upper portion of a stand, a linear scale is attached to the horizontal arm, and the tip of a read head that moves horizontally on the linear scale is attached. In addition to connecting a wire, a back tension mechanism is connected to the rear end of the read head, a rotation guide through which the wire drawn from the linear scale passes at the tip of the horizontal arm, and an angle guide connected to this freely. A wire guide device comprising: a rotation detector for detecting a rotation angle of the angle guide on the rotation guide; and a shaft that rotatably connects the rotation guide and the angle guide, drawn from a linear scale. Install the wire guide ring that guides the wire and detect the angle of the wire bent along this wire guide ring A wire angle detector is provided, a probe head provided with a tip terminal that is brought into contact with the measurement location of the object to be measured is connected to the tip of the wire drawn out from the wire guide device, and the horizontal of the wire measured with the linear scale is further provided. A coordinate calculator is provided that calculates the coordinates of the tip terminal from the amount of movement, the amount of rotation of the rotation guide detected by the rotation detector, and the angle of inclination of the angle guide detected by the wire angle detector. To do.

The wire type three-dimensional coordinate measuring machine according to claim 2 of the present invention is the wire type three-dimensional coordinate measuring machine according to claim 1, wherein the probe head has a wire mounting portion connected to the tip of the wire and a tip terminal mounting portion supporting the tip terminal. It is characterized in that it is pivotably connected via a joint or universal joint.

The wire type three-dimensional coordinate measuring machine according to claim 3 of the present invention is the wire type three-dimensional coordinate measuring machine according to claim 1, wherein the rotation detector provided in the rotation guide has a rotation axis parallel to the linear scale and a wire at the center of the rotation axis. It is characterized by being formed by a hollow encoder to be inserted.

The wire type three-dimensional coordinate measuring machine according to claim 4 of the present invention is characterized in that, in claim 1, the horizontal arm is supported on the upper portion of the stand so as to be movable up and down and rotatable. .

According to the wire type three-dimensional coordinate measuring machine according to claim 1 of the present invention, the rotation detector that can accurately measure the wire drawing length with a linear scale and detects the rotation angle of the angle guide on the rotation guide. At the same time, a wire guide ring that guides the wire drawn from the linear scale is attached to the shaft that rotatably connects the rotation guide and the angle guide, and the angle of the wire bent along this wire guide ring is detected. Since the wire angle detector is provided, the rotation direction and the rotation angle of the wire to which the tip terminal is attached can be accurately measured.

As a result, the three-dimensional coordinates are accurately measured by a simple operation of bringing the probe head with the tip terminal in hand and pulling the wire while bringing the tip terminal into contact with the measurement location of the object to be measured. Roundness, dimensions, etc. can be measured easily. In addition, since it has a simple structure combining a linear scale and an encoder, it can be manufactured in a small size and at a low cost.

According to the wire type three-dimensional coordinate measuring machine according to claim 2, the probe head includes a ball joint or a universal joint, and a wire attachment portion connected to the tip of the wire and a tip terminal attachment portion that supports the tip terminal. Therefore, the linearity of the wire can be maintained, and the center of the tip terminal can be located on the extended line of the straight line so that an accurate coordinate position can be detected.

According to the wire type three-dimensional coordinate measuring machine according to claim 3, the rotation detector provided in the rotation guide is a hollow encoder in which the rotation axis is parallel to the linear scale and the wire is inserted through the center of the rotation axis. Since it is formed, the rotation angle of the wire drawn from the angle guide can be accurately measured, and the structure of the rotation detector can be simplified.

Further, according to the wire type three-dimensional coordinate measuring machine according to claim 4, since the horizontal arm is supported on the upper part of the stand so as to be movable up and down and rotatable, it can be widened in accordance with the shape of the object to be measured. The position coordinates can be measured over the entire area.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 shows a wire type three-dimensional coordinate measuring machine. A ball spline 2 is set up vertically on a top of a stand 1, a horizontal arm 3 is attached thereto, and a linear scale 4 is attached to the horizontal arm 3. Yes. The tip of the horizontal arm 3 is attached with a wire guide device 7 including a rotation guide 5 and an angle guide 6 rotatably connected thereto.

A probe head 9 is connected to the tip of the wire 8 drawn out from the wire guide device 7, and the probe head 9 is provided with a tip terminal 10 at the tip. In the figure, 12 is an object to be measured, 13 is a turntable on which the object to be measured 12 is placed, 14 is a control device, 15 is a personal computer equipped with a coordinate calculator, 16 is a remote control transmitter, and inputs measurement points at the time of measurement. The information is transmitted to the receiver mounted on the control box 14 by radio waves by pressing a button having a predetermined calculation method or the like.

A ball spline 2 is attached to the upper portion of the stand 1, and a spline outer cylinder 19 is attached to the ball spline 2 so as to be movable up and down and rotatable, and the height of the spline can be fixed with a lock lever 20. Yes. The spline outer cylinder 19 is connected to the horizontal arm 3 so that the horizontal arm 3 moves up and down.

An upper bracket 21 is attached to the upper part of the ball spline 2 and a lower bracket 22 is attached to the lower part so as to be rotatable in the horizontal direction. A vertical guide shaft 23 is connected to the upper bracket 21 and the lower bracket 22 in parallel with the ball spline 2, and the middle of the vertical guide shaft 23 passes through the spline outer cylinder 19 to center the ball spline 2. The upper bracket 21 and the lower bracket 22, the spline outer cylinder 19, the vertical guide shaft 23, and the horizontal arm 3 rotate together.

Further, as shown in FIG. 2, the upper portion of the spline outer cylinder 19 is connected to a constant load balance spring 25 provided on the upper bracket 21 and supports the horizontal arm 3 so that it is balanced and kept horizontal when the horizontal arm 3 moves up and down. Yes. Further, a projecting piece 26 is provided on the upper outer periphery of the ball spline 2 protruding upward from the upper bracket 21, and a rotation detector 28 for detecting the rotation angle of the horizontal arm 3 is attached to the upper bracket 21 in the vicinity thereof. ing.

The horizontal arm 3 is formed in a hollow square shape as shown in FIG. 1, and a linear scale 4 is attached in parallel to the inner hollow portion. A read head 30 is movably attached to the linear scale 4 along the longitudinal direction thereof, and the pitch precisely engraved on the linear scale 4 is read by a magnetic method or an optical method, and the position is measured. It has become. A wire 8 is connected to the tip of the read head 30 and a constant load spring 31 is connected to the rear end of the read head 30 so that back tension is always applied to the read head 30.

The wire guide 7 is connected to the tip of the horizontal arm 3 as shown in FIGS. 3 to 5 and changes the direction of the wire 8 drawn from the linear scale 4. It is comprised from the angle guide 6 connected to the rotation freely. As shown in the figure, the rotary guide 5 has a cylindrical body 32 fixed to the tip of the horizontal arm 3, and a hollow encoder 33 through which the wire 8 drawn from the linear scale 4 passes is incorporated on the horizontal arm 3 side. . A rotating body 35 is provided on the outer periphery of the cylindrical body 32 via a bearing 34, and the shaft of the hollow encoder 33 is fixed to the rotating body 35, and rotation detection is performed when the rotating body 35 rotates with respect to the horizontal arm 3. The rotation angle is detected by a hollow encoder 33 serving as a container.

In addition, two guide rollers 37 are provided opposite to each other in the middle of the rotating body 35, and the wire 8 passes between them to restrict the left and right movement of the wire 8. Further, a shaft 38 is attached to the distal end side of the rotating body 35, and a frame-shaped angle guide 6 is rotatably connected to the distal end side of the rotating body 35 so as to sandwich the shaft 38.

As shown in FIG. 4, a wire guide ring 40 is rotatably mounted on a shaft 38 that connects the rotation guide 5 and the angle guide 6 through a bearing, and a presser that is slidably contacted with the shaft and that is provided with two bearings. A guide roller 41 is attached, and the wire 8 is sandwiched between them, and when the angle guide 6 is inclined as shown in FIG. 5, the wire 8 is bent along the wire guide ring 40. As shown in FIG. 3, the angle guide 6 has an encoder 42 attached to the end of the shaft 38 as a wire angle detector for detecting the angle of the wire 8 bent along the wire guide ring 40. .

The angle guide 6 in front of the wire guide ring 40 is provided with two guide rollers 37 facing each other. The right and left deviations are regulated with the wire 8 interposed therebetween, and the tip of the angle guide 6 has Two guide rollers 37 are provided so as to face each other perpendicular to the guide roller 37 and regulate the vertical displacement of the wire 8.

A probe head 9 is attached to the tip of the wire 8 drawn out from the angle guide 6 of the wire guide device 7. The probe head 9 includes a wire attachment portion 43 connected to the tip of the wire 8 and a tip terminal attachment portion 44 that supports the needle-like tip terminal 10 via a universal joint 45 constituted by a ball joint or a universal joint. It is connected. A gripping portion 46 is connected to the universal joint 45, and the linearity of the wire 8 is maintained when the tip end terminal 10 is brought into contact with the surface of the object 12 to be measured by holding the gripping portion 46 by hand during measurement. The center of the tip terminal 10 is positioned on the straight extension line.

Further, the coordinate calculator of the personal computer 15 shown in FIG. 1 detects the horizontal movement amount of the wire 8 measured by the linear scale 4, the rotation amount of the rotation guide 5 detected by the hollow encoder 33 serving as a rotation detector, and the wire angle detection. The coordinates of the tip terminal 10 are calculated from the inclination angle of the angle guide 6 detected by the encoder 42 serving as a container. Reference numeral 48 denotes a reference point, which is provided at the end of the lower bracket 22 of the ball spline 2, for example. The probe terminal 9 is held by hand before measurement and the tip terminal 10 is brought into contact with the reference point 48 before the measurement. By setting, the current positional relationship of the horizontal arm 3 is grasped, and initial positions of the read head 30, the hollow encoder 33, the encoder 42, and the rotation detector 28 are defined.

When the flatness of the object 12 to be measured is measured with the wire type three-dimensional coordinate measuring machine having the above configuration, the object 12 to be measured is first placed on the turntable 13 as shown in FIG. Next, the lock lever 20 of the spline outer cylinder 19 is released, the spline outer cylinder 19 is moved up and down along the ball spline 2 according to the object 12 to be measured, and the horizontal arm 3 is adjusted to a height that allows easy measurement. Lock the lock lever 20. Next, the horizontal arm 3 is rotated in the horizontal direction around the ball spline 2 and adjusted to an angle that is easy to measure. At this time, as shown in FIG. 2, a projecting piece 26 is provided on the outer periphery of the upper part of the ball spline 2 protruding upward from the upper bracket 21, and the rotation angle of the horizontal arm 3 is detected by the upper bracket 21 in the vicinity thereof. Therefore, the rotation angle is detected by the rotation detector 28 and the detected value is sent to the control device 14.

Thereafter, holding the probe head 9 by hand, the tip terminal 10 is brought into contact with the wire 8 extending to the reference point 48, and the switch of the remote control transmitter 16 is turned on here. In this process, the wire 8 is pulled out from the linear scale 4, the rotating body 35 of the rotation guide 5 rotates, and the angle guide 6 tilts back and forth around the shaft 38, and the lead attached to the linear scale 4. The head 30 moves along its longitudinal direction and measures its position.

The wire 8 drawn from the linear scale 4 passes through the shaft of the hollow encoder 33 of the rotation guide 5, and when the angle guide 6 attached to the shaft 38 rotates with the rotating body 35 and further tilts forward and backward, the wire guide ring The wire 8 is bent along 40. At this time, the rotation angle obtained by rotating the rotating body 35 together with the angle guide 6 is detected by the hollow encoder 33 of the rotation guide 5, and this signal is sent to the control device 14. When the angle guide 6 attached to the shaft 38 is tilted back and forth, the tilt angle is detected by the encoder 42 and this signal is sent to the control device 14.

The horizontal movement amount of the wire 8 measured by the linear scale 4 in the state where the leading terminal 10 is in contact with the reference point 48 in this way, and the rotation amount of the rotation guide 5 detected by the hollow encoder 33 serving as a rotation detector, Then, the detection data of the inclination angle of the angle guide 6 detected by the encoder 42 serving as the wire angle detector is sent from the control device 14 to the coordinate calculator of the personal computer 15, where the current positional relationship of the horizontal arm 3 is grasped. The initial positions of the read head 30, the hollow encoder 33, the encoder 42, and the rotation detector 28 are registered as reference point coordinates.

Thereafter, as shown in FIG. 1 and FIG. 6, holding the grip portion 46 of the probe head 9 with the hand, the tip terminal 10 is brought into contact with the point A on the upper surface of the object 12 to be measured, and the switch of the remote control transmitter 16 is turned When turned on, the position coordinates of point A are detected. Next, when the front terminal 10 is brought into contact with the point B on the upper surface of the object to be measured 12 and the switch of the remote control transmitter 16 is turned on, the position coordinates of the point B are detected. Finally, when the front terminal 10 is brought into contact with the point C on the upper surface of the object to be measured 12 and the switch of the remote control transmitter 16 is turned on, the position coordinates of the point C are detected. From the position coordinates of these points A to C and the reference point coordinates, the distance and flatness between the points A, B and C can be measured by the coordinate calculator of the personal computer 15.

As shown in FIG. 4, in the wire guide device 7, the movement of the wire 8 drawn from the linear scale 4 is restricted between two guide rollers 37 provided facing the inside of the cylindrical body 32. Next, the vertical and horizontal movements of the wire 8 are regulated between the wire guide ring 40 and the presser guide roller 41 slidably in contact therewith and provided with two bearings. The left and right movements are restricted between the two guide rollers 37 provided, and the vertical movement is restricted by the guide rollers 37 provided at the tip of the angle guide 6 orthogonal to the guide rollers 37 so that the wire 8 Since the back tension is applied by the constant load spring 31, the axial center of the wire 8 can be prevented from being displaced.

The probe head 9 is connected to a wire attachment portion 43 connected to the tip of the wire 8 and a tip terminal attachment portion 43 that supports the tip terminal 10 via a universal joint 45 formed of a ball joint or a universal joint. Therefore, the linearity of the wire 8 is maintained, and the center of the tip terminal 10 is positioned on the straight extension line, so that an accurate coordinate position can be detected.

FIG. 7 shows a case in which a bucket-shaped object 12 is measured, holding the holding portion 46 of the probe head 9 and holding the tip 10 at three points A, B, and C on the inner periphery of the object 12 to be measured. And by measuring each D point on the inner bottom surface, the upper inner diameter and depth of the bucket-shaped object 12 can be measured.

In the above description, the tip terminal 10 is shown as having a needle shape, but it may be spherical as shown in FIG. The shape of the tip 10 is selected from the object 12 to be measured and the tip 10 suitable for the purpose of measurement. For example, if the tip is a needle-like tip, the tip is at the tip of the needle. Change the correction value so that

Further, by providing a rotation detector such as an encoder on the turntable 13 and detecting the rotation angle, it is possible to measure misalignment when the object 12 to be measured is a cylinder or a cylindrical body. Further, even when the object to be measured 12 is large and the probe head 9 does not reach the measurement point, the measurement can be performed over a wide range by rotating the turntable 13. In addition, by providing a linear scale in the vertical direction along the ball spline 2 and detecting the height of the horizontal arm 3, the shape of the device under test 12 along the vertical direction can be measured. When the DUT 12 is T-shaped, the horizontal arm 3 is lowered and the probe head 9 is pulled upward to measure the bottom of the horizontal portion.

It is a front view of the wire type three-dimensional coordinate measuring machine by one Embodiment of this invention. It is sectional drawing of the ball spline part which raises / lowers the horizontal arm of FIG. It is a horizontal sectional view which expands and shows the wire guide device of FIG. It is a longitudinal cross-sectional view which shows the wire guide device of FIG. FIG. 3 is a front view showing a state in which an angle guide of the wire guide device of FIG. 2 is inclined. It is a top view which shows the measurement point of a to-be-measured object. It is sectional drawing which shows the measuring point of a bucket-shaped to-be-measured object. It is a front view of the probe head which attached the spherical tip terminal by other embodiment of this invention.

Explanation of symbols

1 stand
2 Ball spline
3 Horizontal arm
4 Linear scale
5 Rotation guide
6 Angle guide
7 Wire guide
8 wires
9 Probe head
10 terminal
12 DUT
13 Turntable
14 Control device
15 PC with coordinate calculator
16 Remote control transmitter
19 Spline outer cylinder
20 Lock lever
21 Upper bracket
22 Lower bracket
23 Vertical guide shaft
25 Constant load balance spring
26 Projection
28 Rotation detector
30 readhead
31 Constant load spring
32 Cylindrical body
33 Hollow encoder
35 Rotating body
37 Guide roller
38 axes
40 Wire guide ring
41 Presser guide roller
42 Encoder
43 Wire attachment
44 Tip terminal mounting
45 Universal Joint
46 Gripping part
48 Reference point

Claims (4)

  A horizontal arm is attached to the top of the stand, and a linear scale is attached to the horizontal arm. A wire is connected to the tip of the read head that moves horizontally on the linear scale, and a back tension mechanism is connected to the rear end of the read head. And a wire guide device including a rotation guide through which a wire drawn from the linear scale passes and an angle guide rotatably connected to the wire is provided at the tip of the horizontal arm, and the angle guide wire is provided on the rotation guide. A rotation detector that detects the rotation angle around the axis center is provided, and a wire guide ring that guides the wire drawn from the linear scale is attached to the shaft that rotatably connects the rotation guide and the angle guide. A wire angle detector for detecting an angle of the wire bent along the wire guide ring; Connected to the tip of the wire drawn out from the guide device is a probe head provided with a tip terminal that comes into contact with the measurement location of the object to be measured, and further, the amount of horizontal movement of the wire measured with the linear scale and the rotation detector A wire type three-dimensional coordinate measuring machine comprising a coordinate calculator for calculating the coordinates of the tip terminal from the detected rotation amount of the rotation guide and the inclination angle of the angle guide detected by the wire angle detector.   The probe head is characterized in that a wire attachment portion connected to the tip of a wire and a tip terminal attachment portion that supports the tip terminal are rotatably connected via a ball joint or a universal joint. The wire type three-dimensional coordinate measuring machine according to 1.   The wire type tertiary according to claim 1, wherein the rotation detector provided in the rotation guide is formed of a hollow encoder having a rotation axis parallel to the linear scale and having a wire inserted through the center of the rotation axis. Original coordinate measuring machine.   The wire type three-dimensional coordinate measuring machine according to claim 1, wherein the horizontal arm is supported on the upper part of the stand so as to be movable up and down and rotatable.