JPH1068619A - Central position of hole detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a central position of hole detector for mass production component in which the central position of hole can detected accurately and conveniently through a simple structure. SOLUTION: In a spigot 10 being fitted in the relatively large central hole Wa of an object W and positioned in place, a plurality of sensors 17a-17c for measuring the distance to the inner face of the hole are arranged radially from the center and uniformly on a circumference at a constant distance from the center. The central position of hole detector comprises a processor/controller 20 for operating the center of hole based on the distance data from each sensor and delivering a corrected value to a numeric control machine tool 21. Gap between the hole Wa in a work W and the spigot 10 can be detected immediately, accurately and simultaneously at a plurality of points on the inner circumference of the hole Wa in the work Wa. Furthermore, the central position of the hole in the work can be operated immediately by providing the processor/ controller 20 and a work instruction can be delivered quickly and accurately to the numeric control machine tool 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the center of a hole in a disk-shaped member having a relatively large hole in the center, such as an engine flywheel.

[0002]

2. Description of the Related Art As shown by W in FIG. 5, the flywheel has a relatively large hole Wa at its center as compared with a diameter for fitting a bearing (not shown).
Then, around the hole Wa of the flywheel W, a bolt hole for attaching to a crankshaft is provided. On the outer peripheral portion, a positioning pin hole Wb for attaching a clutch cover (not shown) as shown in FIG. All of these holes are based on the center of the hole Wa. That is, taking the pin hole Wb as an example,
The center of b is indicated by distances a and b from a line X passing through the center O of the hole Wa and a line Y intersecting the line X at right angles through the center O as shown in FIG. / 10
It requires strict regulation of 0 units.

Conventionally, the center position of the hole Wa has been measured and set by the following apparatus and jig. That is,
FIG. 3 shows a vertical machining center 1 for drilling the flywheel W. The machining center 1 is provided with a table 2 which moves left and right (X direction) and back and forth (Y direction). The jig 3 shown in FIG. Reference numeral 4 denotes a vertically moving blade spindle, which is disposed on the table 2, and the table 2 and the spindle 4 are configured to operate by numerical control (NC control). As shown in FIG. 5, the jig 3 has a spigot 5 on which a hole Wa of the flywheel W is fitted on a substrate 3a, and a support member 3b for supporting the flywheel W and a clamp member 3c around the jig. It is arranged.

By the way, in order to satisfy the accuracy, it is necessary to eliminate the influence of the gap between the spigot 5 and the hole Wa. For this reason, conventionally, the spindle 4 of the machining center 1 has conventionally been used.
The touch sensor 6 was attached to the tip, and the hole center position was measured by the sensor 6. That is, first, the touch sensor 6 is placed at the temporary center O ′ in the hole Wa shown in FIG. 4, and the table 2 is moved back and forth so that the three equal points A, B, and C of the hole Wa sequentially contact the touch sensor 6. , Move left and right, O'-
The distances between A ', O'-b, and O'-c were measured, and the true center point O at which the respective distances of O'-b, O'-b, and O'-c were equal was determined from these numerical values.

However, the measurement of the hole center position using the touch sensor 6 has the following problems. That is, the measurement by the touch sensor 6 is performed by generating an electric signal by the operation of the tip 6a.
There is a mechanical error in itself. Further, since the touch sensor 6 is attached to the main shaft 4 by automatic replacement similarly to the blade, there is an error in the attachment. Further, at the time of measurement, the table 2 is moved as described above to bring the inner surface of the hole Wa of the work into contact with the tip, so that the machining center 1 has an error.

As in the present invention, as a centering detection device for detecting the center of a hollow portion at the center of a device, a true centering device which can be fixed at an arbitrary position to a metal wire having a weight suspended from above the hollow portion of the device to be installed. A circular electrode is inserted, and the base end of the measurement support with the gap sensor attached to the tip is brought into contact with the inner surface of the cavity in close proximity to this electrode, and the gap sensor is connected to the indicator to connect the gap sensor and the electrode. A centering detection device in which the gap is represented electrically or magnetically is disclosed in JP-A-59-18402.
Although the technique shown here is suitable for detecting the center of the cavity of a large device such as a vertical turbine or generator due to its configuration, the hole center position of a mass-produced part such as the flywheel is not limited. Is not only large-scale, but also
It is not applicable because it requires a lot of measurement time.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a hole center position detecting apparatus suitable for mass-produced parts, which is simple and can detect accurately and easily without causing a measurement error. Is to do.

[0008]

A hole center position detecting device according to the present invention for solving the above-mentioned problem is provided in a spigot which is fitted and positioned in an object to be measured having a relatively large hole at the center. A plurality of distance sensors for measuring the distance to the inner surface of the hole radially and evenly on the circumference from the center are arranged at equal distances from the center, and the center of the hole is obtained from the distance data from the sensors. And a calculation / control device that outputs the corrected value to the numerically controlled machine tool.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2, 10
Is a spigot according to the present invention, the outer diameter of which is
a is formed on the lower surface thereof, and a projection 13 is formed on the lower surface thereof so as to fit into the mounting hole 12 of the substrate 11, and a recess 14 is formed at the center from the lower surface. And the sensor mounting holes 1
5a to 15c are opened. The sensor mounting hole 15
1 to 15c are equally spaced in the circumferential direction as shown in FIG. 1, that is, they are spaced at intervals of 120 degrees.
15c are accurately drilled so that their axes intersect at the center 10a of the spigot 10. In the example shown in FIGS. 1 and 2, a sensor mounting hole 1 is further provided on the outer periphery of the spigot 10.
A concave portion 16 is formed concentrically with 5a to 15c so that a detection error does not occur in a sensor described later, that is, the sensor mounting holes 15a to 15c.
Care is taken not to be affected by 15c.

Reference numeral 17 (17a to 17c) denotes a distance sensor.
Each sensor 17a is provided in the sensor mounting hole 15a to 15c.
17c are disposed so as to be equidistant from the center 10a of the spigot 10 and, for protection of the sensor, such that the tip end thereof is slightly within the recess 16 from the outer peripheral surface of the spigot 10. It is fixed to the spigot 10 by 18. The number of the distance centers 17 may be any number as long as the number is three or more. However, the sensors are equally arranged on the circumference.
It is important that each of the tip surfaces is substantially equidistant from the spigot center 10a. In this case, the distance sensor 17 is preferably a detector that converts a change in electrical eddy current loss or capacitance into an electric quantity.

Reference numeral 19 denotes a lead line of the distance sensor 17, which is connected to an arithmetic and control unit 20 shown in FIG. 2. The arithmetic and control unit 20 calculates a distance from the distance data sent from each of the sensors 17a to 17c. The center of the hole is obtained by calculation, and the correction value is output to the numerically controlled machine tool 21. The spigot 10 incorporating the distance sensor 17 as described above
The projecting portion 13 on the lower surface is fitted in the mounting hole 12 of the substrate 11 and the bolt 2
2 and fixed to the substrate 11 by the lead wires 19 as described above.
Is connected to the arithmetic and control unit 20.

The substrate 11 to which the spigot 10 is attached is
For example, the vertical machining center 1 shown in FIG. 3 is installed on a table 2 that moves left and right (X direction) and back and forth (Y direction). A support member for supporting W and a clamp member (not shown in FIGS. 1 and 2) are provided. Prior to detecting the hole center position of the work W, the distance sensor 1 is used by using a master work (not shown) as follows.
The measurement origins 7a to 17c are set, and the electrical output is also fixed. This eliminates the need to particularly increase the position accuracy with respect to the center of the spigot. The master work has the same shape as the work W, but a work is prepared in which the size of the hole Wa is minimized with the gap with the spigot 10, and the hole Wa is fitted to the spigot 10, The distance between each of the distance sensors 17a to 17c and the inner wall of the hole Wa is measured. Then, the data is stored in each distance sensor 17a.
It is stored in the computing / measuring device 20 in the origin setting mode as the distance origin of ~ 17c. In this state, the arithmetic / measurement device 20 is switched to the measurement mode, and the measurement is performed as follows. That is, when detecting the hole center position of the work W, the hole Wa of the work W is supported by the support member while being fixed to the spigot 10 and fixed by the clamp member, and then the arithmetic and control device 20 is turned on. Then, the distances between the tip surfaces of the distance sensors 17a to 17c and the inner surface of the hole Wa at the positions corresponding to a, b, and c on the inner surface of the hole Wa of the workpiece W shown in FIG. -The calculation is sent to the control device 20, and the center position O of the hole Wa is immediately obtained. Therefore, based on the determined hole center position, FIG.
Can be output to the numerically controlled machine tool 21 such as the machining center 1, etc. In the example of the machining center 1, the table 2 is moved back and forth, left and right, and a positioning pin is provided immediately below the spindle 4. Drilling can be performed by accurately positioning the hole Wb.

[0013]

According to the hole center position detecting device of the present invention, the object to be measured having a relatively large hole in the center is radially and circumferentially uniformly distributed from the center in the spigot fitted and positioned in the hole. By arranging a plurality of distance sensors for measuring the distance to the inner surface of the hole and equidistant from the center, the work can be simply fitted into the spigot, and the hole of the work at a plurality of locations on the inner periphery of the hole of the work is provided And the gap between the spigot and the spigot can be detected immediately and accurately at multiple locations simultaneously.
By providing an arithmetic and control device that calculates the center of the hole from the distance data and outputs the corrected value to the numerically controlled machine tool, the hole center position of the workpiece is immediately calculated by the calculation, and the numerically controlled machine tool is used. According to the present invention, there is an effect that it is possible to provide a hole center position detecting device suitable for mass-produced parts, which can be easily and accurately detected simply without any measurement error.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a hole center position detecting device of the present invention in a partial cross section.

FIG. 2 is a longitudinal sectional view of the hole center position detecting device of the present invention.

FIG. 3 is a perspective view of a machining center provided with a conventional hole center position detecting device.

FIG. 4 is a plan view showing a relationship between a hole center position and a prepared screw hole in a work.

FIG. 5 is a front view of a conventional hole center position detecting device.

[Explanation of symbols]

1 machining center 2 table 3 jig
4 spindle 5 conventional spigot 6 touch sensor 10 spigot of the present invention 11 substrate 15 (15a to 15c) sensor mounting hole 16 recess 17 (17a to 17c) distance sensor 18 screw
19 Leader wire 20 Arithmetic / control device 21 Numerical control machine tool 2
2 Bolt W Work (flywheel) Wa hole.

Claims (3)

[Claims] 1. An object having a relatively large hole in the center is measured radially and circumferentially uniformly from the center to the inner surface of the hole in a spigot fitted and positioned in the hole. A plurality of distance sensors to be arranged at equal distances from the center, and calculating and calculating the center of the hole from distance data from the sensors, and outputting a correction value to the numerically controlled machine tool. A hole center position detecting device comprising: 2. The hole center position detecting device according to claim 1, wherein a recess concentric with the sensor is formed on the outer periphery of the spigot facing the outer end of the distance sensor. 3. The hole center position detecting device according to claim 1, wherein the distance sensor is disposed such that an outer end thereof is located inside the outer periphery of the spigot.