JPH07225181A - Method and apparatus for measurement of dent property of metal material - Google Patents

Abstract

PURPOSE:To measure the flexure amount and the dent amount of a thin steel plate, an aluminum alloy plate of the like with good efficiency and at low costs by a method wherein a metal material which has been molded and worked to be a convex shape is used as a material to be measured and the flexure amount and the dent amount are measured continuously according to a change in a measuring load to be applied. CONSTITUTION:A material 14 to be measured is attached to a load device 12 by a fixation jig 16, a load is applied to the material 14, to be measured, via an indenter 18 at a definite speed until a prescribed load is applied, and the applied load is confirmed by a CRT 30 for a computer 28, for connection to the load device, which is connected to a load cell 20. Then, the flexure amount of the material 14, to be measured, due to an increase on the load is measured by a dial gage 22, and it is recorded in a recorder 26 via an amplifier 24. At a point of time when the flexure amount has become definite, the load device 12 is raised at low speed, the load is removed from the material 14 to be measured, a zero load is confirmed by the CRT 30, a dent amount (a plastic flexure amount) is measured by the dial gage 22, and the dent amount is recorded in the recorder 26. This procedure is repeated, and the flexure amount and the dent amount are measured continuously in an on-line manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the dent property of a metal material and an apparatus therefor, and particularly to a method for measuring the dent property of a metal material such as a steel plate or an aluminum alloy plate used as a lightweight material for automobiles and the like. Regarding the device.

[0002]

_2. Description of the Related Art Energy consumption and CO ₂ associated with global warming
Due to problems and the like, weight reduction of automobiles is being actively promoted. Above all, attention has been focused on high-tensile steel plates and aluminum alloy plates, which can significantly reduce weight. However, reducing the thickness of the steel plate or switching to an aluminum alloy plate causes a decrease in rigidity, deterioration of dent property, and the like, which is a major problem in adoption. Therefore, there is an increasing demand for accurately measuring the dent property of the lightweight material. Dent property means that if a local load is applied to the metal material for some reason, a dent (plastic deformation) may remain after the load is removed. Evaluate. Further, this depression is called a dent, and similarly, the depth of the depression is called a dent amount (dent depth).

FIGS. 5A and 5B show a conventional dent property measuring device for metallic materials. Here, FIG. 5a shows a load device used in the conventional method for measuring the dent property, and FIG.
The measurement system of the dent amount in the conventional dent property measuring method is shown in b. A conventional denting load device 50 shown in FIG. 5a.
Is composed of a surface plate 52, a weight 54, an indenter 56, and a load load (weight) 58.

Here, the measuring material 60 is placed on the surface plate 52, and the measuring material 60 is fixed by the weight 54. The weight 54 fixes the measuring material 60 on the surface plate 52 and prevents the measuring material 60 from being laterally deformed by the load 58 and changing its width. Next, a load 58 having a predetermined load is applied to the measuring material 60 via the indenter 56 installed at the predetermined position of the measuring material 60. Then, the load 58 is removed, and the dent amount is measured using the dial gauge 62 as shown in the dent amount measuring system of FIG. 5B.

As described above, in the conventional dent characteristic measuring method using the conventional dent characteristic measuring device shown in FIGS. 5a and 5b, the load device 50 is applied to the sample (measuring material) 60 of the press-formed metal material. After applying a constant load with the weight 58, the load applied to the load device 50 is removed, and data is manually collected by the dial gauge 62. Also, although the weight 58 of several kinds of loads is used as the applied load,
A measuring material 60 is required for each of these several types of applied loads 58. Further, since the amount of dent is measured after removing the applied load 58, naturally, the amount of deflection cannot be measured. Therefore, not only a lot of time, materials, and man-hours are required, but also measurement data are likely to have individual differences.

Further, in the case of measurement opportunity, that is, in the case of a sample of a press-molded metal material, depending on the molding opportunity or the material, a storage method after molding causes a slight individual difference. However, in the conventional method of measuring the dent property, there is a time lag between the time when the load is applied to the measuring material and the time when the dent amount is measured.

[0007]

In metallic materials, for example, materials used for automobile skins, the dent property is an important part property that also affects the quality of the automobile body, and care should be taken in the same manner as in automobile design. Is required.

Therefore, the object of the present invention is to solve various problems based on the above-mentioned prior art, to provide an efficient, low-cost metal material such as a thin steel plate or an aluminum alloy plate used for an outer panel of an automobile. It is an object of the present invention to provide a method for measuring the dent property of a metal material and an apparatus therefor capable of measuring the amount of deflection and the amount of dent.

[0009]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted various studies on a dent property measuring method and a dent property measuring device for a metal material, and as a result,
We have found a method and apparatus for accurately and quickly measuring the dent property of metallic materials. That is, the present invention is a method for measuring the dent property of a metal material, which uses a metal material press-molded in a convex shape as a measurement material, and continuously changes the measurement load applied to the metal material. The present invention provides a method for measuring the dent property of a metal material, which comprises measuring the deflection and the amount of dent. Here, it is preferable that the measured load is continuously applied at a constant speed by a hydraulic device or a mechanical device.

Further, the present invention is an apparatus for measuring the dent property of a metal material, which comprises a jig for fixing a measurement material made of a metal material press-molded in a convex shape, and a jig for fixing the measurement material at a constant speed. The present invention provides a denting property measuring device for a metal material, comprising: a load device that applies a load dynamically; and a measuring unit that determines a change amount of the measuring material due to the load as a position.

[0011]

According to the dent property measuring method and apparatus for metallic materials of the present invention, first, a metallic material press-molded into a convex shape, which is a measuring material, is attached to a load device, and a constant speed is applied through an indenter. Apply a load to the measuring material until the specified load is reached. At the same time, the output from the load cell is confirmed by the display device, and the amount of deflection of the measuring material as the load increases is automatically measured by the dial gauge and automatically recorded in the recorder.

Next, when the load reaches a predetermined value, the load is removed from the measuring material at a constant speed until the load becomes zero, and after confirming that the load on the measuring material is zero by the display device, the amount of plastic deflection is measured. (Dent amount) is measured. Then, after measuring the dent amount, in order to perform the measurement with the next applied load,
The above-mentioned predetermined load is changed and the measurement is repeated according to the procedure of this measuring method.

Therefore, according to the dent property measuring method and apparatus for a metal material of the present invention, one measuring material does not need many measuring materials (dent property measuring material) unlike the conventional dent property measuring methods. The amount of deflection that accompanies the load change continuously,
Also, the amount of dent can be measured. Further, according to the dent property measuring method and apparatus for a metal material of the present invention,
Since the measurement data is digitally displayed and continuously recorded on the recording paper, and the data read from the recording paper and the digital value of the measuring device correspond to each other, the measurement data can be easily confirmed.

According to the dent property measuring method and apparatus for a metal material of the present invention, the load is changed at a constant speed by using a pressurizing device having a hydraulic or mechanical device. Not only can the measurement be performed, but errors due to individual differences and measurement opportunities do not occur, and the measurement accuracy can be improved by using the load cell together. Furthermore, according to the dent property measuring method for a metal material and the apparatus thereof of the present invention, since load can be automatically applied by machine operation, measurement data can be recorded and collected in a short time, which significantly burdens the operator. There is also the great advantage of being mitigated.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The metal material denting property measuring method and apparatus according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a plan view of an embodiment of a metallic material denting property measuring apparatus according to the present invention. Measuring device 1 shown in FIG.
0 is a loading device 12 that applies a load to the measuring material 14, and a fixing jig 1 that fixes the measuring material 14 to the dent property measuring device 10.
6, an indenter 18 having a spherical pressing surface for pressing the measuring material 14 with a load applied by the loading device 12, a load cell 20 for measuring the applied load, and a dial for measuring the amount of bending and the amount of dent of the measuring material 14. The gauge 22 includes an amplifier 24 that amplifies a measured value such as a flexure amount and a dent amount, and a recorder 26 that records the measured value.

Here, the load device 12 may be a device for applying a fluid pressure such as hydraulic pressure or air pressure, or a device for mechanically applying a load by using a screw, a link or the like. For example, the load can be controlled in units of 0.1 kg, the load can be applied at a constant speed instead of the impact value, and the display device of the load cell 20, for example, a digital display, can be used even while measuring the dent property. Etc.
It is preferable that the applied load can be checked at any time. By having these functions, the amount of bending and the amount of dent of the measuring material 14 can be continuously measured. Next, the load cell 20 measures the load applied to the measuring material 14 by the load device 12, and outputs the measured load to the control computer 28 of the load device 12 in order to display the measured load on the display device 30. Is preferable, and one having high resolution under low load is preferable.

Next, the dial gauge 22 is the measuring material 14
It is a measuring instrument for measuring the amount of flexure and the amount of dent, and it is necessary to have an output to the recorder 26 for recording the measurement data, and the gauge accuracy is high in order to catch a minute change. Those that can be attached and adjusted are preferable. Next, the recorder 26 records the amount of bending and the amount of dent of the measuring material 14. The recorder 26 may be of any type as long as it can leave these data on recording paper, tape, memory, etc., but if it is a digital system that can easily convert the amount of change, measurement becomes easier. preferable.

Here, the measuring material 14 is fixed to the load device 12 by the fixing jig 16, and the amount of bending and the amount of dent of the measuring material 14 are measured by the following method. The measuring material 14 is a metallic material press-molded into a convex shape,
For example, a mild steel plate or an aluminum alloy plate having a vertical and horizontal length of 300 mm and a surface curvature radius (R) of 2000 mm is used. However, the present invention is not limited to this, as long as it is a metal material pressed into a convex shape,
The vertical and horizontal lengths, the radius of curvature of the surface, the material of the measuring material 14, and the like may be appropriately determined without limitation.

According to the dent characteristic measuring method of the present invention, the dent characteristic measuring apparatus of the present invention is used.
The procedure for continuously measuring the amount of bending and the amount of dent of the measuring material 14 is shown below.

(1) First, as described above, the measuring material 14 is attached to the load device 12 by the fixing jig 16. (2) The load device 12 applies a load to the measuring material 14 through the indenter 18 at a constant speed until a predetermined load is reached. (3) The output from the load cell 20 is confirmed by the display (display device) 30 of the load device control computer 28 connected to the load cell 20 shown in FIG. 1, such as a CRT display. (4) The amount of deflection of the measuring material 14 due to an increase in load is measured by the dial gauge 22 and recorded on recording paper by the recorder 26 via the amplifier 24. (5) When the predetermined load, that is, when the amount of deflection becomes constant, the load device 12 is slowly moved up to remove the load from the measuring material 14. (6) After confirming that the load on the measurement material 14 is zero by the display 30 of the load device control computer 28 shown in FIG. 1, the plastic deflection amount (dent amount) is measured. (7) After measuring the dent amount, the above-mentioned predetermined load is changed in order to perform the measurement with the next applied load, and the procedure is returned to the procedure (2) of this measurement example and the measurement is repeated.

Here, FIG. 2 shows the dent property measuring apparatus for metallic materials of the present invention as described above, according to the measuring method of the present invention.
FIG. 4 is an example of a schematic diagram of a measurement chart when the deflection amount and the dent amount of the measurement material 14 are continuously measured. In the figure, first, when a load is applied at a constant speed from a state where the amount of deflection is zero, the amount of deflection is δ ₁ when the load becomes a predetermined load 1. Then, the amount of deflection is δ ₁
When the load is reduced at a constant speed from the above state, the deflection amount at the time when the load becomes zero, that is, the dent amount (plastic deformation amount) is d ₁ . Subsequently, from this state, that is, the state where the plastic deflection amount (dent amount) is d ₁ , the predetermined load 2,
Repeat the measurement at 3, ... In the figure, the deflection amounts under loads 2 and 3 are δ ₂ and δ ₃ , and similarly, the dent amount is d
₂ and d ₃ . Further, in the figure, only the predetermined load 3 is shown, but if necessary, the loads 4, 5, ...
・ It goes without saying that you can continue as long as you like.

Next, a concrete example of the case where the dent amount of the measuring material is continuously measured by the measuring method of the present invention using the dent property measuring apparatus of the present invention shown in FIG. 1 will be described.

The measurement materials used for the measurement of the dent property are a mild steel plate (SPCE) having a plate thickness of 0.75 mm and a baking hardenable 6000 series (Al-plate having a plate thickness of 1.0 mm).
Mg) An aluminum alloy plate. The measurement material has a bottom of 300 mm × 300 mm and a height of 40 m as shown in FIG.
A m-shaped press having a radius of curvature of 2000 mm was used. Here, the reason why it has a radius of curvature is for conducting an experiment assuming, for example, an automobile outer panel component. For comparison, a mild steel plate was measured in the same manner as a flat plate before pressing, and an aluminum alloy plate was similarly measured in a heat treated material. The measurement results of mild steel plate and aluminum alloy plate,
They are shown in FIGS. 3 and 4, respectively. As is clear from FIG. 3 and FIG. 4, by the dent property measurement by the measuring method of the present invention using the device of the present invention, the dent property improvement by the shape of the steel plate and the dent property improvement effect by the heat treatment of the aluminum alloy plate are appropriately measured. We were able to.

Finally, the following table shows the comparison results of the dent property measuring method (apparatus) of the present invention and the conventional dent property measuring method (apparatus).

[0026]

As described above in detail, according to the method and apparatus for measuring the dent property of a metal material of the present invention, the amount of deflection with a continuous load change in one measuring material, and
The dent amount can be measured, the measured data can be digitally displayed and continuously recorded on the recording paper, and the data read from the recording paper and the digital value of the measuring device can be associated with each other. It is easy to check the data. Further, according to the dent property measuring method and apparatus for a metal material of the present invention, by using a load device that uses a fluid pressure such as hydraulic pressure or a mechanical pressure, the load can be finely and accurately controlled, and a constant speed can be obtained. Not only can the measurement be performed while changing the applied load, the error due to the individual difference or the measurement chance does not occur, but the measurement accuracy can be improved by using the load cell together. Furthermore, according to the dent property measuring method and apparatus for a metal material of the present invention, by using a pressurizing device having a hydraulic device or a mechanical device as a loading device, it is possible to automatically perform load loading by machine operation, There is also a great advantage that the measurement data can be recorded and collected in a short time and the burden on the operator can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a metallic material denting property measuring apparatus according to the present invention.

FIG. 2 is a schematic diagram of a measurement chart showing the amount of deflection when a load is applied to the measurement material and the amount of dent after the load is removed by using the dent property measuring device for a metal material of the present invention.

FIG. 3 is an example graph showing a measurement result of dent property of a mild steel sheet (SPCE) by a dent property measuring method of a metal material of the present invention.

FIG. 4 is an example graph showing the measurement result of the dent property of the aluminum alloy plate by the dent property measuring method of the metal material of the present invention.

5A is a plan view of a conventional dent property measuring apparatus for a metal material, and FIG. 5B is a plan view showing a conventional dent property measuring method for a metal material.

[Explanation of reference numerals] 10 dent property measuring device 12 load device 14 measuring material 16 fixing jig 18 indenter 20 load cell 22 dial gauge 24 amplifier 26 recorder 28 load device control computer 30 display 50 dent property measuring device 52 surface plate 54 56 Indenter 58 Load (Weight) 60 Measuring Material 62 Dial Gauge

Claims (3)

[Claims] 1. A method of measuring the dent property of a metal material, comprising using a metal material press-molded in a convex shape as a measuring material, and measuring the load applied to the metal material according to a change in the measured load.
A method for measuring the dent property of a metal material, which comprises continuously measuring the deflection and the amount of dent. 2. The dent property measuring method for a metal material according to claim 1, wherein the measured load is continuously applied at a constant speed by a hydraulic device or a mechanical device. Sex measurement method. 3. An apparatus for measuring the dent property of a metal material, which comprises a jig for fixing a measurement material made of a metal material press-molded in a convex shape, and a load applied to the measurement material continuously at a constant speed. A denting property measuring device for a metal material, comprising: a load device to be applied; and a measuring means for determining a change amount of the measuring material due to a load as a position.