JPH036414A - Evaluating apparatus for shape of inner peripheral surface - Google Patents

Abstract

PURPOSE:To evaluate the shape of the inner peripheral surface of a machined substance simply, quickly and accurately by detecting a rotational angle of a rotary board by a rotational angle sensor and a displacement of the inner peripheral surface of the machined substance from the center of rotation by a displacement sensor. CONSTITUTION:A machined substance 28 is mounted by fitting a hole 32 of the machined substance 28 on a shaft 16. This hole 32 is easier to machine than an inner peripheral surface 30 and it can be machined with high precision. By using the hole 32 as a basis, accordingly, the inner peripheral surface 30 can be measured precisely. In this state, contacts 22, 24 and 26 are brought into contact with the inner peripheral surface 30 of the machined substance 28. Then, the machined substance 28 is once rotated together with a rotary board 14 manually. A rotational angle in the rotation is detected by a rotational angle sensor 18, while a displacement of the inner peripheral surface 30 is detected by a displacement sensor 20. Subsequently, signals from the sensors 18 and 20 are subjected to signal processing 34 and the relationship between the rotational angle and the displacement is obtained.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to an inner peripheral surface shape evaluation device.

(b) Conventional technology When evaluating the shape of an inner peripheral surface that is concave in the axial direction and has a non-circular shape,
Conventionally, a three-dimensional coordinate evaluation machine having a contactor movable in three axial directions has been used. The data obtained by the three-dimensional coordinate evaluator is subjected to predetermined arithmetic processing as disclosed in, for example, Japanese Unexamined Patent Publication No. 61-23906, and the deviation from the reference shape, which is a memorized reference shape, is calculated. . In this way, for example, the shape of the inner circumferential surface of the workpiece is evaluated.

(C) Problems to be Solved by the Invention However, the evaluation using the above-mentioned three-dimensional coordinate evaluation machine has the problem that it takes a long time (for example, 20 to 30 minutes) to prepare for the evaluation and to perform the actual evaluation. Although it is applicable to the evaluation of a relatively small number of items such as press molds, it cannot be applied to the evaluation of workpieces produced in large quantities. Furthermore, three-dimensional coordinate evaluation machines are generally large-sized and there are restrictions on the environments in which they can be installed, making it difficult to incorporate them into production lines within factories. The present invention aims to solve the above-mentioned problems and to enable the inner peripheral surface shape of a workpiece to be easily, quickly, and accurately evaluated in a mass production process.

(d) Means for Solving the Problems The present invention solves the above problems by rotating the workpiece and measuring the rotation angle and displacement from the rotation center to evaluate the shape of the inner peripheral surface. do. That is, the inner circumferential surface shape evaluation device according to the present invention has a rotation mechanism that rotates together with the workpiece (28) when the second part (32) is attached to the shaft (16). (14), a rotation angle sensor (18) that detects the rotation angle of the rotation mechanism, and a rotation angle sensor (18) that detects the displacement of the inner circumferential surface (30) of the workpiece with respect to the shaft, which is the rotation center of the rotation mechanism. displacement sensor (
20), and a signal processing device (34) that compares and evaluates the relationship between the rotation angle and the displacement obtained by the signals from the rotation angle sensor and the displacement sensor with a preset reference value. Note that the symbols in parentheses indicate corresponding members in the embodiments described later.

(E) The workpiece is attached to a rotation mechanism and rotated, the rotation angle of the rotation mechanism is detected by a rotation angle sensor, and the displacement of the inner peripheral surface of the workpiece from the center of rotation is detected by a displacement sensor. By doing so, a predetermined relationship between rotation angle and displacement can be obtained. The shape of the inner circumferential surface is evaluated by comparing the data thus obtained with preset reference data.

Example) Examples are shown in FIGS. 1 to 4. As shown in FIG. 1, a rotary disk 14 is rotatably provided on a base 12 fixed to a bed 10. The rotary disk 14 rotates around a shaft portion 16 that is integral with the base 12. The rotation angle of the rotary disk 14 can be measured by a rotation angle sensor 18. Shaft 1
A displacement sensor 20 is provided in the center of 6.
The contacts 22, 24 and 26 of the displacement sensor 20 are connected to the shaft portion 1.
It protrudes outward in the radial direction of 6. Contacts 22, 24 and 26 contact the inner circumferential surface 30 of a workpiece 28 which is supported on and rotates about the shaft 16. The workpiece 28 has a shape as shown in FIGS. 2 and 3, with a hole 32 capable of fitting into the shaft 16. Rotation angle sensor 18
The signals from the displacement sensor 20 and the displacement sensor 20 are input to the signal processing device 34 . The processing unit 34, which is connected to the microcomputer, processes the signals as described below based on the signals from the rotation angle sensor 18 and the displacement sensor 20.

Next, an actual evaluation operation using this inner peripheral surface shape evaluation device will be explained. First, the hole 32 of the workpiece 28 is inserted into the shaft portion 16.
Workpiece 28 is attached as shown in FIG. 1 by snapping. This hole 32 is easier to machine than the inner circumferential surface 30 and can be machined with a high grain size.

Therefore, by using this hole 32 as a reference, the inner circumferential surface 30, which will be described later, can be measured with good precision. In this state, the contacts 22, 24 and 26 are connected to the inner peripheral surface 30 of the workpiece 28.
comes into contact with. Next, the workpiece 28 is rotated together with the rotary disk 14 by a pivoting operation. The rotation angle during rotation is detected by the rotation angle sensor 18, and the displacement of the inner peripheral surface 30 is detected by the displacement sensor 20. Signals from the rotation angle sensor 18 and the displacement sensor 20 are input to a signal processing device 34 and processed thereby. This provides the relationship between rotation angle and displacement. The relationship between rotation angle and displacement is, for example, as shown by the solid line in FIG. 4. In addition, the curve shown by the broken line in FIG. 4 is the design reference value. The signal processing device 34 evaluates the data thus obtained as shown in FIG. 4 using the following three methods. The first method outputs the data shown in FIG. 4 as is, making it possible to grasp the deviation of the actual evaluation data from the design reference value.

Thereby, it is possible to grasp the shape deviation in each part of the inner circumferential surface 30. Further, it is also possible to determine pass/fail based on whether the maximum value of the error is less than or equal to a predetermined value. Next, as a second method, the difference between the evaluation value and the reference value is integrated, and the obtained integral value (this corresponds to the area between the solid line and the broken line in Figure 4) is less than or equal to a predetermined value. The inner circumferential surface 30 is evaluated as it is. As a result, it is possible to determine whether the evaluated shape of the inner circumferential surface 30 on average matches the base 4 (value).Next, as a third method, the evaluation value is differentiated to calculate the value per unit length. The shape of the inner circumferential surface 3o is evaluated based on whether or not the change in:1: is less than a predetermined value.This makes it possible to evaluate whether there are any parts that are not smooth in the shape of the inner circumferential surface 3o. The processing of the data as described above is performed simultaneously for each of the three contacts 22, 24 and 26. By comparing the three data, it is possible to evaluate the shape granularity of the inner circumferential surface 30 in the axial direction. can also be done.

In this embodiment, the turntable 14 is rotated by manual operation, or alternatively, it may be driven by a motor. Further, although the displacement sensor 20 is of a type having a contactor, a non-contact type sensor such as an optical sensor may also be used.

32...hole, 34...(G processing equipment.

(G) As described in detail, according to the present invention, the workpiece is rotated based on the processed part with high processing accuracy, the rotation angle and the displacement of the inner circumferential surface are evaluated, and the obtained rotation Since the shape of the inner circumferential surface was evaluated from angle and displacement data, 3
Compared to the case where evaluation is performed using a dimensional coordinate evaluation machine or the like, evaluation can be performed accurately and in a short time with simple work, and pass/fail determination can also be performed automatically.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an inner circumferential surface shape evaluation device that is an embodiment of the present invention, Fig. 2 is a diagram showing a workpiece to be evaluated, and Fig. 3 is a cross section taken along line III-III in Fig. 2. 4 are diagrams showing the relationship between rotation angle and displacement. 14... Rotating disk, 16... Shaft part,

Claims (1)

[Claims] An inner circumferential surface shape evaluation device for evaluating the inner circumferential surface shape of a workpiece, comprising: a rotation mechanism that rotates together with a predetermined machined portion of the workpiece while being attached to a shaft portion; , a rotation angle sensor that detects the rotation angle of the rotation mechanism, a displacement sensor that detects the displacement of the inner circumferential surface of the workpiece with respect to the shaft portion that is the rotation center of the rotation mechanism, and a rotation angle sensor and a displacement sensor. An inner circumferential surface shape evaluation device comprising: a signal processing device that compares and evaluates the relationship between the rotation angle and the displacement obtained by the signal with a preset reference value.