JPS61184414A - Three-dimensional measuring device - Google Patents

Abstract

PURPOSE:To automate the measurement of a three-dimensional coordinates position, in a control unit, by setting optimum measuring algorithm at every measuring point. CONSTITUTION:A three-dimensional measuring device 2 is vertically provided on a machine base 3 so as to be capable of being moved along the X-coordinates on a surface plate 1 on the basis of the order from a control unit. A main touch sensor 17 and an auxiliary touch switch 19 are attached to the outer surface of a sensor base. Measuring algorithm to each measuring point of a work is set to said control unit and the movement control of both touch sensors 17, 19 is performed according to said algorithm and the three-dimensional position of each measuring point is measured on the basis of the detection signals from both touch sensors 17, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a three-dimensional measuring instrument, and more particularly, to a measuring instrument capable of automatically measuring the three-dimensional position of a measuring object.

(Prior Art) For example, when constructing the framework of an automobile, each brace item (assembly item) must be assembled in a normal state. Traditionally, this check has been performed at an appropriate stage during the assembly process. The check performed here is to measure how far a specific position on the assembly product deviates from the normal assembly position, and a measuring device called a layout machine is generally used. .

(Problem to be Solved by the Invention) In measurement using this layout machine, it is necessary to bring the measuring needle into contact with each measuring point, but in the case of the conventional layout machine, it is necessary to bring the measuring needle into contact with each measuring point. is limited. For example, with a measuring needle for measuring a predetermined surface,
This is because it would be difficult to subsequently measure the position of a bolt standing on this surface. Therefore, in the conventional case, when measuring the position of a complex and variously shaped object such as an automobile body, it is necessary to manually change the position of the measuring needle frequently. However, because high measurement accuracy is required, adjustments must be made every time the attachment is replaced.
It has been impossible to automatically measure all measurement points since this requires extremely cumbersome work. Therefore, the present invention aims to automate the measurement of three-dimensional coordinate positions.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows. In other words, a measuring needle is attached to the main body of the measuring instrument in such a way that it can sense both the needle tip and the side, and the direction of the needle tip can be arbitrarily selected within a three-dimensional plane, and The measuring needle is controlled according to a measurement algorithm, and a control unit is configured to read the three-dimensional coordinate position of the measuring point based on the detected value from the measuring needle.

(Operation) Therefore, according to the above configuration, an optimal measurement algorithm is set for each measurement point in the control unit. For this reason, in actual measurement, the orientation of the tip of the measuring needle is first selected, and its three-dimensional position is measured using the optimal measurement procedure according to this measurement point.

(Example) Hereinafter, an example embodying the present invention will be described in detail with reference to the drawings.

In the drawings, 1 is a surface plate with X-Y coordinates, and 2 is a three-dimensional measuring instrument placed on the surface plate 1.

The three-dimensional measuring device 2 is installed upright on the machine base 3,
It can move along the X coordinate axis on the surface plate 1 based on commands from a control unit (not shown in detail). In addition, a column 4 is vertically installed on the machine base 3, and along the column 4,
In other words, the machine head 5 is mounted so as to be slidable along the Z axis. Further, the machine head 5 is horizontally provided with an arm 6 formed of a pipe material, and extends so as to be slidable in the horizontal direction with respect to the machine head 5. A base 7 is attached to the tip of the arm 6 with bolts or the like, and a step motor 8 is attached to the inner surface of the base 7. The output shaft 9 of the step motor 8 is screwed into the sensor base 10 through the base 7, and is fixed with nuts 11 and 12.

Therefore, the sensor base 10 can be lowered by the step motor 8, and in this example, both bases 7.10 are aligned via the spigot 13 in order to eliminate rotational wobbling. Also, between both bases 7 and 10, there is a sensor base 10.
As a stopper means, a spring 1 is provided on the sensor base 10 side.
A pole stopper 15 is provided which is biased at a point 4, and locking holes 16 are bored at every 90° on the base 7 side, into which the pole stoppers 15 are respectively fitted. and,
A main touch sensor 17 is provided on the outer surface of this sensor base 10.
is attached in the radial direction via a fixing member 18 made of an elastic material (urethane rubber).

That is, the main touch sensor 17 moves within the Z coordinate plane by 90'''
This means that it can be angularly displaced.

Furthermore, a sub touch sensor 1 is provided on the outer surface of the sensor base 10.
9 is a fixing member 20 made of an elastic material in the same manner as above.
It is attached coaxially with the output shaft 9 of the step motor 8 via. Therefore, both sensors 17.19 are 9
They are attached at an angle of 0°, and both are shaped like needles so that sensing can be done not only at the tip but also at the side.

Note that the aforementioned control unit has a measurement algorithm set for each measurement point on the workpiece, and controls the movement of both touch sensors 17.19 according to this algorithm, and also controls the movement of both touch sensors 17.19 based on the detection signals from both touch sensors 17.19. It is now possible to measure the three-dimensional position of each measurement point.

Next, an actual example of measurement using the three-dimensional measuring device of this example formed as described above will be specifically explained.

However, the measurement work described below corresponds to the frame of the car, and in order to check whether the parts are assembled in the correct condition, the actual assembly is done in position and the normal assembly is in the position. This refers to the work of measuring the deviation of

The above measurement algorithm is specifically as shown on the next page.

That is, in this example, the shape of the measurement point is classified into five types, and whether the main or sub touch sensor 17 or 19 is used, and in the case of the main touch sensor 17, its rotational position is roughly determined based on the sensor. A total of four types of conditions are set for each measurement point, including whether to measure at the tip of the needle or from the side, and the direction in which the sensor approaches.

Now, prior to the measurement work, the position (Xi, Yj, Zk) and the above-mentioned measurement algorithm for each measurement point are stored in the control unit for proper assembly of each measurement point on the workpiece. When measuring the position of a hole 21 among the measurement points, for example, as shown in FIG. 3, the main Move one of the secondary touch sensors 17, 19 to this point.

At this time, the three-dimensional measuring instrument 2 is displaced in the X-axis direction as the machine base 3 moves along the surface plate 1, and is displaced in the Y-axis direction as the arm 6 slides. are displaced by a predetermined distance in the Z-axis direction by moving up and down along the column 4.

Also, depending on the direction of the hole 21, the main/sub touch sensor 17.
19 is selected and the main touch sensor 17 is selected at the same time, the rotational position every 90 degrees is also selected by driving the step motor 8. In this way, the tip of the sensor is guided to the correct position (the center of the hole 21) where the hole 21 should originally be drilled. At this time, as shown in Figure 3, if the actual hole position is shifted upward from the position of the normal assembly (in the figure, the state of the regular assembly is a solid line, and the position of the actual assembly is are shown by imaginary lines.

), when the sensor 17 (19) is first shifted in the negative direction with respect to the Shift 1 and similarly contact position (x2.Yj)
Read. Then, the normal assembly returns to the position again, and this time the same procedure is performed in the Y-axis direction, and the contact position (X
i, Yl) and (Xi, Y2) respectively.

As a result, the two-dimensional center coordinate position of the hole 21 is measured as (x1+X2/2.Y1+Y2/2). Thereafter, the sensor is shifted so that the tip of the sensor comes out of the hole 21 in order to measure the Z coordinate position. In other words, the needle tip is (x1+X2/2 +D/2, Y1+Y2/2 +D
/2, Zk-a). Here, D
is the diameter of the hole 21, and a is a parameter that is determined within the maximum error range so that the assembly will not deviate any further in the Z-axis direction, and to avoid interference between the sensor and the hole 21.

After this, if the sensor is lowered along the Z-axis direction and the contact position of the needle tip is read, the three-dimensional coordinate position of the hole 21 (x1
+X2/2. Y1+Y2/2. Z) is output to the control unit.

The above example shows the case where the hole 21 is shifted in the negative direction (upward in the figure) with respect to the two axis directions, but in the opposite case, that is, when it is shifted in the positive direction with respect to the Z-axis direction,
- Shifting the sensor in the Y plane will result in the sensor not being able to contact the hole edge. For such cases, the following procedure is set in the measurement algorithm in this example.

In other words, if the sensor does not make contact even if it is shifted by a fixed shift mb on each side in the The procedure is now repeated.

Next, the procedure for measuring the three-dimensional coordinate position of the stud bolt 22 will be explained with reference to FIG. However, in the same figure,
The normal position is shown by a solid line, and the actual position is shown by an imaginary line. The exact center coordinate position of the root of the bolt 22 is (Xi, Yj, Zk).

In this case, first, with Yj fixed, shift the sensor from the negative direction along the X axis to the above exact size position, and then tighten bolt 2.
Read the coordinate position (xl, Yj) where it touched 2. next,
The sensor is detoured and shifted from the positive direction to the full size position along the X axis, and the coordinates (X2.Yj) of the contact position are read. Thereby, the center coordinates (X10X2/2) of the bolt 22 in the X direction are calculated. The same procedure is performed in the Y-axis direction, and from these the X-Y center coordinate axis of the bolt 22 (xi÷X2/2.Y1+Y2
) is read as Regarding the Z coordinate position, if necessary, the sensor may be lowered and the coordinate position at the contact position may be read, as in the case of measuring the hole position described above.

Finally, the procedure for measuring the surface position will be explained with reference to FIG. However, in the figure, the normal state is shown by a solid line, and the actual state is shown by an imaginary line. Then, when measuring the surface position, a specific position of the regular surface 23 is selected, and the coordinate position here is set as (Xi, Yj, Zk), and how far the actual surface is from the regular surface in terms of A measurement is made of the deviation.

First, if you shift the sensor from the positive direction of the X-axis while fixing (Yj, 7kl), the needle tip will come into contact with the surface 23 on the way to the exact size position, so the coordinate value regarding the X-axis can be found here. However, contrary to the illustration, if the actual surface position is located further back than the normal position, the needle tip will not be able to make contact even if the sensor shifts to the correct size value. During the algorithm, after the shift to the exact value,
Further, a secondary shift company is set so that the constant shift is performed.

According to this example, although not explained in detail, in addition to measuring the positions of the holes 21, bolts 22, and surfaces 23 described above, position measurements of ridge lines or edges are also carried out continuously as the measuring instrument main body 2 moves. It can be done.

In addition, in this example, the case where two types of sensors 17 and 19, main and sub-sensor, are used selectively is illustrated, but instead of this, as shown in FIG. It may be possible to make the rotation around the arm 6 and the output shaft 2, 5a of the step motor 25 possible.

(Effects of the Invention) As detailed above, according to the present invention, the measuring needle can perform sensing not only at the tip but also at the side, and the direction of the tip can be arbitrarily set within a three-dimensional plane. This allows the measurement range to be expanded as much as possible when the measuring instrument is in a fixed position, eliminating the need for troublesome needle replacement.
Work will be made smoother. In addition, since measurements are made according to an algorithm determined for each measurement point, while sequentially moving to various measurement points,
Moreover, it can be measured automatically and accurately. By this,
This is extremely significant, especially in multi-point measurements, as it dramatically shortens the measurement time.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the entire coordinate measuring instrument, Figure 2 is a front view showing the area around the measuring needle, Figure 3 is an explanatory diagram showing the hole position measurement work, and Figure 4 is the bolt position measurement. FIG. 5 is an explanatory diagram showing the surface position measurement work, and FIG. 6 is a perspective view showing another embodiment of the measuring needle. 2... Three-dimensional measuring device 6... Arm

Claims (1)

[Claims] This is a measuring device for measuring the three-dimensional coordinate position of a measurement point, and is capable of sensing both the tip and side of the measuring device, and the direction of the tip can be arbitrarily selected within the three-dimensional plane. and a control unit that controls the measuring needle according to a measurement algorithm preset for each measuring point and reads the three-dimensional coordinate position of the measuring point based on the detected value from the measuring needle. A three-dimensional measuring instrument characterized by comprising: