JPH0138484Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an apparatus that easily and continuously measures the shape of an object to be measured on the same circumference using a three-dimensional coordinate measuring machine.

For example, a case will be described in which a shape on the circumference of a cylindrical portion 2 of an object 1 as shown in FIG. 1 is measured at a certain distance R from the center O using a three-dimensional coordinate measuring machine.

Conventionally, when measuring shapes on the same circumference, a rotary table equipped with a scale for reading the rotation angle is installed on the table of a three-dimensional coordinate measuring machine, and the center of the rotary table is set at the center of rotation of the rotary table. Place the object to be measured so that they match, place the probe at the tip of the Z-axis of the three-dimensional coordinate measuring machine in contact with a point on the circumference to be measured, and clamp the X- and Y-axes.
A method has been considered in which only the Z-axis is left free, and then the rotary table is rotated and the shape is measured from the amount of displacement of the Z-axis at every predetermined angle.

However, in this conventional method, the rotary table is expensive, the work of aligning the center of the object to be measured with the rotation center of the rotary table is complicated and time-consuming, and since the object to be measured is placed on the rotary table, There were drawbacks such as the fact that there was a limit to the size of the object to be measured.

Another method is to leave the X, Y, and Z axes free and move the probe so that the displayed values of X and Y match the previously determined X and Y values of each measurement point on the same circumference. It is not unthinkable to measure the shape from the Z value at each measurement point, but this method requires the operator to move the probe to each measurement point while looking at the displayed X and Y values to match the values. However, this method has the disadvantage that the work is complicated and the measurement takes time, and furthermore, it has been impossible to carry out continuous measurements.

This invention solves the drawbacks of these conventional devices and provides a device that can easily and continuously measure the shape of an object to be measured on the same circumference using a three-dimensional coordinate measuring machine.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

In the figure, 3 is the Z-axis of the coordinate measuring machine, and a rotary probe 4 rotatable about the center line of the Z-axis 3 is held at the lower end of the Z-axis. At the tip of the rotary probe 4 is a ball 5 that contacts the measurement point of the object to be measured 1.
is held with its center aligned with the center line of the Z-axis. In the illustrated example, the rotary probe 4 has a U-shape, but its shape is not particularly limited, and of course may be straight.

A horizontal arm 6 is fixed at an intermediate position of the rotary probe 4, and two rods 7 and 8 are attached to this horizontal arm 6 with the rotary probe 4 in between.
is held adjustable.

That is, the rods 7 and 8 are held on the horizontal arm 6 by universal joints 9 and 10, respectively, so that the protrusion amount, angle, direction, etc. of the rods 7 and 8 can be adjusted and fixed as appropriate. It's becoming like that.

The operation of measuring the shape of an object on the same circumference using the present invention having such a configuration will be explained. First, the object to be measured 1 is set on the table of the three-dimensional coordinate measuring machine, and then the protrusion amount, angle, direction, etc. of the rods 7 and 8 are adjusted, and the cylindrical part 2 is
When the dimension from the center O of the Z-axis 3 to the center of the contact ball 5 becomes the desired dimension R to the circumference to be measured, both rods are fixed. In this case, the protrusion amount, angle, direction, etc. of both rods do not need to be the same; for example, in the case of a measured object in which the cylindrical portion 2 serving as the reference has a large diameter portion and a small diameter portion, one rod may have a large diameter portion. The other rod may be brought into contact with the small diameter portion and adjusted and fixed to the desired dimension R.

After doing this, if the Z-axis 3 is rotated with the tips of the rods 7 and 8 always in contact with the cylindrical part 2, the Z-axis 3 will rotate with a radius R around the center O of the cylindrical part 2.
The shape on the same circumference can be easily measured by sequentially reading the amount of displacement of the Z-axis 3 which moves up and down following the shape at that time.

Recently, almost all three-dimensional coordinate measuring machines have adopted a data processing system using a computer. By determining the Z value, the shape of the object to be measured 1 can be continuously measured without stopping the contact ball 5 at each measurement point.

In the above embodiment, when the object to be measured 1 has a cylindrical portion 2, the tips of the rods 7 and 8 are brought into contact with the cylindrical portion 2, but depending on the object to be measured, the cylindrical portion 2 may protrude. There are some that do not have a cylindrical part, or some that do not have a cylindrical part. In this case, by setting a suitable cylindrical jig 11 on the object to be measured as shown in FIG. 4, it is possible to carry out the same measurement as in the above embodiment.

In addition, in the above embodiment, the circumference to be measured is located outside the cylindrical part with which the tip of the rod comes into contact, but of course the circumference to be measured is located inside the cylindrical part. Even in this case, the shape can be easily measured by adjusting both rods appropriately.

As detailed above, according to the present invention, it is possible to easily, reliably, and continuously measure shapes on the same circumference from the center of the object to be measured, significantly improving measurement efficiency, and making it practical. The effect is great.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of an object to be measured, Fig. 2 is a perspective view showing an embodiment of the present invention, Fig. 3 is a plan view of an embodiment of the invention, and Fig. 4 shows an auxiliary cylindrical part. An explanatory diagram when provided. DESCRIPTION OF SYMBOLS 1...Object to be measured, 2...Cylindrical part, 3...Z-axis, 4...Rotary probe, 7, 8...Rod, 9, 10...Universal joint.

Claims (1)

[Scope of utility model registration request] A rotary probe held at the lower end of the Z-axis of the coordinate measuring machine so as to be rotatable about the axis of the Z-axis, a contact ball fixed to the tip of the rotary probe concentrically with the axis of the Z-axis, and the tip thereof. 1. A shape measuring device using a coordinate measuring machine, comprising two rods that are adjustable and held on the rotary probe so that their positions are in contact with a reference cylindrical portion.