JPH09236409A - Measuring gauge for relative slippage amount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure a small amount of relative slippage created between two members which are fastened with a contacting pressure without using an expensive measuring instrument in terms of a measuring gauge for the relative amount of slippage between two articles. SOLUTION: A plurality of parallel lines are printed at regular intervals on each of transparent thin plates. Both of the ends of the thin plate 1 on which horizontal parallel lines are printed and the thin plate 2 on which diagonal parallel lines are printed are bonded to each other in an interrelationship wherein an angle θbetween the parallel lines is satisfied with an equation of 'tanθ= 9:1/10-1/100'. Fixing adhesives 3, 4 to be adhered to members to be measured are attached to the other ends of both of the thin plates, respectively. In this condition, the thin plate 1 is attached to one article 5 by the adhesive 3 and the thin plate 2 is attached to the other article 6 by the adhesive 4 by nipping the contacting faces of the members. After that, the bonded section 7 of the thin plates 1, 2 is cut off to separate the thin plates when measuring. When the articles 5, 6 are relatively moved to each other, a moire fringe which is created by the interference of the parallel lines on the thin plates shifts, thereby obtaining the relative slippage amount by reading the shifting amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relative slip amount measuring gauge between two members.

[0002]

2. Description of the Related Art When two members fastened with a surface pressure are repeatedly subjected to a fatigue load, a minute relative slip occurs between the two members, resulting in wear and fatigue cracks, leading to fracture. This phenomenon is called fretting fatigue.

The occurrence of fretting fatigue is known to be related to the surface pressure and the amount of relative slip between two objects. As shown in FIG. 5, the occurrence of cracks on the surface pressure-relative slip diagram, Non-occurring areas are distinguished. That is, it is important to measure the relative slip amount between two objects in the evaluation of fretting fatigue.

The amount of relative slip between two objects is usually small,
Since the amount is on the order of 0.01 mm, highly accurate measurement is required, and a relative slip amount detector (clip gauge) using the conventional resistance wire strain gauge a as shown in FIG.
As shown in FIG. 4B, G is attached to the end faces of the contact portions of two objects (boss and shaft), and the amount of slip is measured.

[0005]

By the way, in the slip amount measurement by the clip gauge of the prior art as described above, there is a disadvantage that expensive dynamic equipment such as a dynamic strain measuring device and a recording device is required.

According to the present invention, in order to solve the above problems,
The purpose of the present invention is to provide a measuring gauge that enables accurate measurement without applying expensive measuring equipment by applying the principle of the moire method as a method of optically enlarging a small amount of relative slip between objects. I am trying.

[0007]

As a structure for achieving the above object, a relative slip amount measuring gauge of the present invention has a structure in which a contact surface between two objects to be fastened with a surface pressure is provided. In the relative slip measurement gauge that can be attached by 3, the gauge consists of two transparent thin plates with parallel lines printed at equal intervals, and for one of the thin plates with horizontal parallel lines printed, The parallel lines of the other thin plates are arranged at a low angle from the horizontal of the parallel lines, one end of each of the thin plates is joined to each other, and the other end is provided with an adhesive for attaching to the two objects respectively. It is characterized by that.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 shows a relative slip amount measuring gauge of the present invention, (a) is a perspective view,
(B) is a state diagram in which the same gauge is attached to two objects, respectively. 2 is a principle diagram of relative slip amount measurement, and FIG. 3 is an explanatory diagram of moire fringes.

In the present invention, the principle of the known moire method is applied as a method for optically enlarging a small amount of relative slip between two objects.

An example of a technique for optically measuring the displacement of a medium using moire fringes generated by superimposing striped patterns is disclosed in Japanese Patent Laid-Open No. 50-23656 or Japanese Patent Laid-Open No. 5-6356.
What is shown in 7-184918 gazette etc. is known.
Further, conventionally, application of moire fringes to displacement measurement has been actively carried out.

Two transparent thin plates on which a plurality of parallel lines are printed at equal intervals are prepared, and one of the two objects is attached so that the parallel lines are horizontal.

When one of the two objects has a parallel line inclined at an angle θ from the horizontal and two transparent thin plates are superposed and seen through, a moire fringe as shown in FIG. 3 is observed.

In carrying out the above method, the measurement accuracy is controlled by mounting the angle θ between the horizontal parallel lines and the inclined parallel lines respectively mounted on the two objects in a predetermined correct positional relationship. An embodiment of the invention for realizing this is shown in FIG.

In FIG. 1, out of two plates in which a plurality of parallel lines are printed on a transparent thin plate at equal intervals, a thin plate 1 on which horizontal parallel lines are printed and a thin plate 2 on which inclined parallel lines are printed are parallel line groups. Are arranged in a mutual relationship such that the angle θ formed by is tan θ = 1/10 to 1/100, and one ends thereof are joined to each other.
(Joint 7)

Adhesives 3 and 4 for fixing to the object to be measured are attached to the other ends of the thin plates 1 and 2, respectively.

In this state, as shown in FIG. 1 (b), the thin plate 1 is attached to one object 5 with the adhesive 3 by sandwiching the contact surfaces of the objects 5 and 6 to be measured, and to the other object 6. Attach the thin plate 2 with the adhesive 4.

After that, when measuring the relative slip amount of both objects, the joining portions 7 of the thin plates 1 and 2 are cut off to connect the thin plates 1 and 2, and the thin plate 1 is bonded to the object 5 by the adhesive 3.
In addition, the thin plate 2 is independently attached to the object 6 with the adhesive 4, and the angle θ formed by the parallel line groups printed on the respective plates can be properly attached.

When the objects 5 and 6 move relative to each other, the moire fringes generated by the parallel lines on the thin plate 1 and the thin plate 2 interfering with each other move. Therefore, by reading the moving amount Δx shown in FIG. The slip amount Δy is obtained by the equation (1).

Δy = Δxtan θ (1)

That is, to summarize the operation of the present invention, as shown in FIG. 2, a thin plate printed with horizontal parallel lines attached to one of two objects and a thin plate printed with inclined parallel lines attached to the other are shown in FIG. When the distance Δy is slid in the y-axis direction, the moire fringes are enlarged in the x-direction and moved by Δx.

At this time, there is a relationship of Δx = Δy / tan θ, and the actual amount of slip Δy is a movement optically enlarged by 1 / tan θ.

From this, the movement amount Δx of the moire fringes in the x-axis direction Δx
By optically measuring, the relative slip amount Δy is obtained as Δy = Δxtan θ (1) as described above.

As a device for reading the movement amount Δx of the moire fringes, a general dimensional reading method such as a magnifying glass with a scale, a low magnification microscope, and photography can be used.

[0024]

As described above, according to the relative slip amount measuring gauge of the present invention, it is necessary to use an expensive measuring device for measuring the minute relative slip amount generated between two objects fastened with a surface pressure. It is possible to measure with high accuracy.

[Brief description of drawings]

FIG. 1 shows an example of a relative slip amount measuring gauge of the present invention,
(A) is a perspective view, (b) is a mounting state view of the same gauge.

FIG. 2 is a principle diagram of relative slip amount measurement.

FIG. 3 is an explanatory diagram of moire fringes.

FIG. 4 shows a conventional slip gauge for measuring slip,
(A) is an enlarged view, (b) is a mounting state diagram of the same gauge.

FIG. 5 is an explanatory view of the effects of surface pressure and slip amount on the occurrence of fretting fatigue cracks.

[Explanation of symbols]

 1, 2 Thin plate 3,4 Adhesive 5,6 Object (member) 7 Joined part

Claims (1)

[Claims] 1. A relative slip amount measuring gauge, which is attached with the contact surface sandwiched between the contact surfaces of two objects that are fastened with a surface pressure, wherein the gauge is printed with a plurality of parallel lines at equal intervals. One of the thin plates is printed with a horizontal parallel line, and the parallel line of the other thin plate is arranged at a low angle from the horizontal of the parallel line. A relative slip amount measuring gauge characterized in that one ends of the thin plates are joined to each other, and the other ends thereof are provided with an adhesive for attaching to each of the two objects.