JPS5824192Y2 - Test piece clamping plate for thin plate spring testing equipment - Google Patents

Description

[Detailed description of the invention] This invention is an improvement of a test piece clamping plate for a thin plate spring testing device for measuring the Young's modulus of a thin plate spring test piece using the relationship between the bending deflection of a cantilever beam and the load. It is related to.

Generally, when measuring the Young's modulus of a thin leaf spring material (usually 0.2 to 2.Q mm thick), one end is fixed, a concentrated load is applied to the free end, and the Young's modulus is measured from the relationship between the load and bending deflection. In this type of thin plate spring testing apparatus, thin plate spring test pieces with a width of about 1Q mm are used, and thin plate springs with a width of about 1Qmm are used for testing on the upper and lower thin plate spring testing apparatus. A fixed end condition is formed by being held between the single clamping plates.

However, the plate for clamping the test piece of the conventional thin plate spring test device has a smooth surface on the entire surface that comes into contact with the thin plate spring test piece, and the contact area with the thin plate spring test piece is wide. The plate thickness is 0.5 to 2. If the thin spring test piece is relatively thick and curved, such as Qmm, even if a large force is applied, it will not be possible to tighten the thin spring test piece sufficiently. If there are metal pieces, scale, dirt, etc. in between, the tightening will be insufficient.
Furthermore, as the tests were repeated, the fixed end became fatigued and the tightening at the fixed end became insufficient, making the distance from the fixed end to the load point, which is important in measuring Young's modulus, inaccurate. There was a drawback that measurements could not be performed.

The present invention solves the drawbacks of the test piece clamping plate in the conventional thin plate spring testing apparatus, and is capable of always stabilizing the conditions of the fixed end of the thin plate spring test piece. It provides:

More specifically, the present invention provides a test piece clamping plate that constitutes a chuck part of a thin plate spring testing device that measures Young's modulus by holding a thin plate spring test piece with a plate width of around 10 mm in a cantilever shape. The present invention relates to a plate for tightening a test piece for a thin plate spring testing device, characterized in that both ends of the contact surface with the spring test piece are convex portions in a direction perpendicular to the longitudinal direction of the thin plate spring test piece.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the test piece clamping plate for a thin plate spring testing apparatus according to the present invention will be described in detail below with reference to the drawings.

Fig. 1 is a front view showing a state in which a thin plate spring test piece is fixed using an embodiment of the test piece clamping plate for a thin plate spring testing device according to the present invention, and Fig. 2 is a right side view of Fig. 1. , FIG. 3 is a perspective view of the test piece clamping plate portion in a state in which a thin plate spring test piece is fixed using the test piece clamping plate for a thin plate spring testing device according to the present invention, and FIG. FIG. 3 is a perspective view of another embodiment in the same state as in FIG.

In the drawings, 1 is the main body of the thin plate spring testing device.

This test device main body 1 includes a base 1a, four columns 1b provided upright on the base 1a, and these four columns 1b.
A top plate 1C installed horizontally above and this top plate 1C
The handle 1e is fixed to the male screw 1d above the top plate 1C, and the handle 1e is fixed to the male screw 1d above the top plate 1C.

2 is an upper test piece clamping plate which is pressed downward by a male screw 1d below the top plate 1C, and 3 is a lower test piece clamping plate whose lower surface is placed in contact with the base 1a. It is a board for use.

These upper and lower test piece clamping plates 2 and 3 constitute a chuck part, and in these test piece clamping plates 2 and 3, the upper test piece clamping plate 2 is on the lower surface, and the lower Each of the test piece clamping plates 3 has a contact surface with the thin plate spring test piece T on its upper surface.

Either one of the upper and lower test piece clamping plates 2 and 3 is used as the test piece clamping plate for the thin plate spring testing apparatus according to the present invention.

In the illustrated embodiment, the lower test piece clamping plate 3 is a test piece clamping plate for a thin plate spring testing device according to the present invention.

The plate for tightening a test piece for a thin plate spring testing device according to the present invention has a plate width of about 1Q mm and a plate thickness of usually 0.2 to 2.0 mm. Both ends of the fixed end and the part furthest from the fixed end of the portion of the test piece T to be clamped and fixed are interposed by convex portions A and B in a direction perpendicular to the longitudinal direction of the thin plate spring test piece T, The protrusions A and B may be integrally constructed with the test piece clamping plate for the thin plate spring testing device as shown in Fig. 3, but if the protrusions A and/or B are worn or damaged. It is preferable to have an exchangeable structure that can be easily fixed to the main body of the test specimen clamping plate with screws or the like, as shown in FIG. 4, so that only the convex portion can be replaced and fixed.

Next, the effects of the plate for tightening a test piece for a thin plate spring testing device according to the present invention will be explained.

In the thin plate spring test device 1, the plate 2.3 for clamping the test piece has a thickness t (mm) and a width b (mm) (7) A concentrated load w is applied to the thin plate spring test piece T at a distance of l (mm) from the fixed end. (g)
The amount of deflection f (mm) when applied is E: Young's modulus of thin plate spring test piece T (kg/mm2) ■:
The Young's modulus E of the thin plate spring test piece T can be determined because it is expressed by the cross-sectional moment of inertia (mm') of the thin plate spring test piece T.

As can be seen from the formula for calculating Young's modulus, the distance l from the fixed end of the thin plate spring test specimen T to the load point is affected by the cube of the term. If the tightening plate is bent, the distance l during the actual test is larger than the calculated distance l, so the amount of deflection increases, and the calculated Young's modulus is much smaller than the actual Young's modulus. This makes it impossible to accurately measure the blowfish rate.

In order to eliminate this drawback, when the male screw 1d screwed into the top plate 1C of the thin plate spring testing device main body 1 is tightened by turning the handle 1e, the lower end of this male screw 1d is pressed and the test piece is tightened. In order to increase the compressive stress at the fixing part of the thin plate spring test piece T which is clamped and fixed by the test piece clamping plates 2 and 3, convex parts A and B are provided at both ends of one of the test piece clamping plates 2 and 3. The area for pressing and clamping the thin plate spring test piece T is reduced by applying a large compressive stress with the same pressing force by the male screw 1d, thereby preventing the thin plate spring test piece T from bending, metal pieces, scales, etc. that have entered the clamping fixing part. The test piece clamping plate for a thin plate spring testing device according to the present invention completely flattens dust, etc. and eliminates the influence of the sagging of the fixed end of the test piece clamping plate.

In this invention, the convex parts A and B must have the same height and the contact surface with the thin plate spring test piece T must be smooth, and the height should be 0.1 to 10.0 mm and the width should be 3 to 10 mm. Considering the rigidity of the test piece clamping plate, the convex portion A,! −
The contact area between B and the leaf spring test piece T is preferably about 215 times the planar area of the test piece clamping plate.

This is because if the height is less than 1 mm, the effect of providing the protrusions A and B will be lost in the case where scale adheres between the protrusions A and B, and it will not be possible to use the protrusions repeatedly. This is because the protrusions A and B will wear out during the process, and the effect of providing the protrusions A and B will be lost, which is undesirable. Also, if the height exceeds 10.0 mm, the protrusions A and B This is because if the width of the convex portions A and B is narrow, the convex portions A and B may curve depending on the tightening pressure and cannot form a fixed end, which is undesirable.

In addition, if the width is too narrow, the protrusions A and B will wear out significantly during repeated use, and the effect of providing the protrusions A and B will be lost in a short period of time, and the tightening pressure will cause the protrusions A
, 3 mm because if the height of B is high, the protrusions A and B will curve and become unable to form a fixed end, which is not preferable.
The above is necessary, but on the other hand, if the width is too wide, the tightening pressure per unit area will decrease and there will be no difference from the conventional smooth tightening plate, which is undesirable, so the width is 19.
It is preferable that the thickness be less than mm.

Example Plate thickness Q: 5 mm, width: 10 mm, length: 150 mm (near), "ffe" cold rolling rate: 0.20.30.60.7
0% SUS 301 material was heated at about 400°C for 1 hour for aging treatment, and when measuring the Young's modulus of this material, a high plate was placed at both ends of a test piece clamping plate with a planar shape of 60 mm in length and 5 Q mm in width. A case where the plate for tightening a test piece for a thin plate spring testing device according to the present invention having a convex portion with a height of 0°5 mm, a length of 60 mm, and a width of 1 Q mm is used as a lower plate for tightening a test piece, and the above planar shape. Measurements were made by two testers for each case using a conventional test piece clamping plate for a thin plate spring testing device whose entire surface on which the test piece abuts is smooth.

Both of these measurement methods are based on the repeated deflection test method specified in JIS H3130 (Beryllium copper, phosphor bronze, and nickel silver plates and strips for springs), and the distance from the fixed end to the position where concentrated load is applied. l is a thin plate spring test piece T
so that it is 100 times the thickness of the plate, i.e. l-50mm
A method was adopted in which Young's modulus was determined by using a 125 g weight as a concentrated load and measuring the amount of deflection.

The results are as shown in Fig. 5 marked with △ (when the thin plate spring test piece T is taken parallel to the rolling direction) and mark (when the thin plate spring test piece T is taken perpendicular to the rolling direction). When a smooth test piece clamping plate was used, there was a variation in the measured values of around ±1000 kg/m m2, and the measured values were within a fairly small range of values, but the differences were large. When using the test piece clamping plate according to the present invention, the variation is ±200 kg/m as shown by the circle.
The measurement accuracy was improved as it became around m2, and the measured value was about 3000 kg when using the test piece clamping plate according to the present invention than when using the conventional test piece clamping plate.
/mm2 also showed a high value, and this value was close to the Young's modulus determined by a tensile test or vibration method, and was found to be a more accurate measurement result.

This is because the result (△ mark) when a thin plate spring test piece T is taken parallel to the rolling direction becomes a small value especially at a high rolling rate. is around Hv530, so the contact area with the thin plate spring test piece T is as large as 10 x 60,600 mm2 in the conventional plate for tightening the test piece for the thin plate spring testing device, so it is difficult to completely correct the curved curl caused by rolling. Whereas it was not possible to form a fixed end by crimping, in the case of the test piece clamping plate according to the present invention, the contact area with the thin plate spring test piece T was as small as 10 x 10 x 2-22-2O0. It is considered that the ○ mark indicates that the curved curl caused by rolling was corrected and a condition that can be considered as a fixed end was created.

In addition, when the rolling rate is low, the influence of curvature due to rolling mentioned above is small and the hardness also shows a low value, so the influence of curvature of the thin leaf spring test piece T is small, but the thin leaf spring test piece T is still tightened to form a fixed end. In order to do this, the contact area between the thin plate spring test piece T and the test piece clamping plate for the thin plate spring testing device is large in the conventional clamping plate, so the clamping stress is small and a perfect fixed end cannot be formed. It has been found that the Young's modulus can only be determined as a small value.

As detailed above, the plate for tightening a test piece for a thin plate spring testing apparatus according to the present invention is inexpensive and easy to use since it simply has convex portions at both ends of the plate for tightening a test piece for a conventional thin plate spring testing apparatus. Although it can be manufactured, it is possible to improve the measurement accuracy of Young's modulus and bring the measured value itself closer to the accurate value. Since the test piece clamping plate according to the present invention is used, when tightening the test piece, one side of the thin plate spring test piece is the same as the test piece clamping plate on the side other than the test piece clamping plate according to the present invention. Since it can be tightened by contacting the entire smooth test piece contact surface of the thin plate spring test piece, no trouble occurs during the tightening work of the thin plate spring test piece, and its practical value is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a state in which a thin plate spring test piece is fixed using an embodiment of the test piece clamping plate for a thin plate spring testing device according to the present invention, and Fig. 2 is a right side view of Fig. 1. , FIG. 3 is a perspective view of the test piece clamping plate portion in a state in which a thin plate spring test piece is fixed using the test piece clamping plate for a thin plate spring testing device according to the present invention, and FIG. A perspective view of another embodiment in the same state as
FIG. 5 is a diagram showing Young's modulus measurement results when using and not using the test piece clamping plate for a thin plate spring testing device according to the present invention. 1...Thin plate spring testing device main body, 1a...
・Base, 1b...Column, 1C...Top plate,
1d...Male thread, 1e...Handle,
2... Upper test piece clamping plate, 3...
Lower test piece clamping plate, A, B...Convex portion, T.
...Thin leaf spring test piece.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a test piece clamping plate constituting a chuck part of a thin plate spring testing device that measures Young's modulus by holding a thin plate spring test piece with a plate width of about 1Q mm in a cantilever shape. A plate for tightening a test piece for a thin plate spring testing device, characterized in that both ends of the contact surface with the thin plate spring test piece are convex portions in a direction perpendicular to the longitudinal direction of the thin plate spring test piece. 2. A plate for tightening a test piece for a thin plate spring testing device as set forth in claim 1 of the utility model registration claim, in which the convex portion is replaceable with respect to the main body for tightening the test piece.