JPH01297536A - Inspecting device for cam shaft - Google Patents

Abstract

PURPOSE:To exactly detect 'sagging' caused by TIG quenching by detecting a cam position and determining a window position from a base circle part of an image and executing an inspection of a defect with regard to the inside of the window. CONSTITUTION:A processing means 4 drives a shaft holding means 2 and turns a base circle part Eb of a cam E of an object to be inspected in the image pickup direction. The first image which has been obtained therein becomes an image containing a part of the circle part Eb, and 'sagging' is not generated in an end edge Ef. Subsequently, the means 4 compares light and darkness on the X axis of the first image and a prescribed threshold value, and detects positions X1, X2 of the cam E. Next, a cam shaft S is rotated by the means 2, the cam surface Ec is turned in the image pickup direction, and the second image containing the cam surface Ec is obtained. In this state, by setting a window W to a position containing an area between the positions X1, X2 which have been detected, and executing an inspection of a defect with regard to the inside of the window W, 'sagging' of an end edge Ed can be detected exactly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a camshaft inspection device. More specifically, the present invention relates to a camshaft inspection device that can suitably inspect camshafts that have been subjected to TIG hardening treatment.

(Prior Art) The general configuration of a camshaft inspection device is as shown in FIG.

A shaft holding hand 1iIt2 that holds the camshaft at an angle, a camera means 3 that obtains an R image of the camshaft S, and a processing device 4 that controls the shaft holding means 2 and the camera means 3 to inspect the cam surface of the camshaft S. It consists of

In the conventional apparatus, the camshaft S is rotated by the shaft holding means 2, and the cam surface Ee of the cam E to be inspected is directed in the imaging direction (arrow), as shown in FIG.

The image obtained at this angle is as shown in FIG. 8, and the contrast on the X axis is as shown in FIG. 9. In other words, the portion of the cam surface EC is bright (and the portion toward the shaft is dark).

Therefore, an appropriate threshold value I. By determining , the positions X+ and X2 of the edge of the cam surface EC can be detected.

Then, as shown in FIG. 10, the detected positions X1, x
A window W is set to include the area between the two, and it is inspected whether there is a defective part within the window W.

[Problem to be solved by the invention]

In recent years, cam surfaces have been subjected to TIG hardening, but this TAG hardening can sometimes cause droop on the edges of the cam. The shaded area in FIG. 11 represents "who".

However, as shown in FIGS. 12 and 13, the image portion corresponding to the edge Ej of the cam E becomes a dark area due to the "sloping", so that the image part corresponding to the edge Ej of the cam E becomes a dark area, so that It will be erroneously detected as if there was an edge at position X, +δl, X2-62.

In this case, as shown in FIG. 14, the window W becomes smaller than the actual width of the cam E, and the "who" part goes outside the window W, which causes the problem of not being able to detect the "who", which is one of the defects. occurs.

Therefore, an object of the present invention is to provide a camshaft inspection device that can suitably inspect even if "sag" occurs due to the TIG hardening process.

[Means to solve the problem]

The camshaft inspection device of the present invention is a device for inspecting defects on the cam surface of a camshaft that has been subjected to TIG hardening treatment, and includes a first image pickup device for obtaining a first image including a base circle portion of the cam. means, window position determining means for determining the window position by detecting the cam position from the base circle portion of the first image;
The apparatus is characterized in that it is equipped with a second imaging means for obtaining an image, and a scanning means for setting the window in the second image and inspecting the inside of the window for defects. be.

[Operation] TIG hardening treatment is performed on the cam surface, but not on the base circle portion of the cam (Eb in Fig. 11).Therefore, “slop” will not occur on the base circle portion. do not have.

Therefore, by detecting the position of the cam based on the image of the base circle portion of the cam, the actual position of the cam can be determined without being influenced by "who" and the window position can be determined accurately.

That is, if the window is set in the image of the cam surface, the edge of the cam will always be included in the window, and if a "slop" occurs, it will be discovered as a defect.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings. Here, FIG. 1 is a schematic diagram of the configuration of a camshaft inspection device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the cam position in a state in which the first image is obtained, and FIG. 3 is an example of the first image. figure,
Figure 4 is a brightness distribution diagram for the first image, Figure 5 is a diagram for the second image.
FIG. 6 is an explanatory diagram of the cam position in a state in which an image is obtained, and FIG. 6 is an exemplary diagram of the second image and the window. Note that the present invention is not limited to the embodiments shown in the figures.

As shown in FIG. 1, a camshaft inspection device 1 includes a shaft holding means 2, a camera means 3, and a processing means 4.

The processing means 4 drives the shaft holding hand Vi2 to
As shown in the figure, the base circle portion Ei of the cam E to be inspected is oriented in the imaging direction (arrow).

The image obtained here, that is, the first image, is the base circle portion E1. The image includes the part, but since the top of the base circle part has not been subjected to TIG hardening, there is no sagging on the edge E.

As shown in FIG. 4, the processing means 4 compares the brightness and darkness of the first image on the X axis with a predetermined darkness value L0, and determines the position of the cam E
Detect 1 + X 2. As mentioned above, cam E
The edge E of the base circle part E.

Since no "whole" occurs in , it is possible to accurately obtain the position of cam E, X l + X2.

Next, the processing means 4 rotates the camshaft S using the shaft holding means 2 so that the cam surface EC faces the imaging direction (arrow) as shown in FIG.

The image obtained here, that is, the second image, includes a portion of the cam surface EC, as shown in FIG.

Then, the processing means 4 performs the above detection! X.

, X2 is set at a position including the area between them.

Next, the processing means 4 inspects the inside of the window W for defects, but as can be understood from FIG. This makes it possible to suitably discover "who" the person is.

〔Effect of the invention〕

According to the present invention, there is provided an apparatus for inspecting defects on the cam surface of a camshaft that has been subjected to TIG hardening treatment. window position determining means for determining the window position by detecting the cam position from the base circle portion of the first image; and a second image for obtaining the second image including the cam surface portion.
There is provided a camshaft inspection apparatus characterized by comprising: an imaging means, and an inspection means for setting the window in the second image and inspecting the inside of the window for defects; Even in the case of a camshaft that has undergone treatment, it is now possible to suitably inspect it.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of a camshaft inspection device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the cam position in a state in which the first image is obtained, and FIG. 3 is an exemplary diagram of the first image. Fig. 4 is a brightness distribution diagram in the first image, Fig. 5 is an explanatory diagram of the cam position in the state in which the second image is obtained, Fig. 6 is an illustration of the second image and window, and Fig. 7 is a conventional device. 8 is an illustration of the image obtained in the state shown in FIG. 7, FIG. 9 is a brightness distribution diagram on the X axis of FIG. 8, and FIG. 1O is an illustration of the image obtained in the state shown in FIG. An exemplary diagram showing the relationship between the image and the window shown in
Fig. 11 is a view equivalent to Fig. 7, Fig. 12 is a view equivalent to Fig. 8, Fig. 13 is a view equivalent to Fig. 9, and Fig. 14 is a view corresponding to Fig. 7 for a cam with droop caused by the TIG hardening process. is a diagram corresponding to the same Figure 1θ. [Explanation of symbols] 1... Camshaft inspection device 2... Shaft holding means 3... Camera means 4... Processing means S... Camshaft E... Cam E to be inspected. ...Base circle part 巳f...Edge edge Ec of base circle part...Cam surface EJ...Edge edge W of cam surface...Window ■...Adjacent cam. Applicant Daihatsu Motor Co., Ltd.

Claims (1)

[Claims] 1. An apparatus for inspecting defects on the cam surface of a camshaft that has been subjected to TIG hardening treatment, which comprises: a first imaging means for obtaining a first image including a base circle portion of the cam; window position determining means for determining the window position by detecting the cam position from the base circle portion;
a second imaging means for obtaining a second image including the cam surface portion;
A camshaft inspection device comprising: inspection means for setting the window in the second image and inspecting the inside of the window for defects.