JP2000176547A - Stress relieving method for metal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove a strain of a metal material, in which a strain is exhibited in external deformation, without using a large scale device as well as large operation energy. SOLUTION: An inside bent part 11b of a bent part due to a strain A existing halfway in the longitudinal direction in a prescribed length metal material 11 is first heated and expanded, the metal material 11 is straightened. Successively, the heated part is quickly cooled to stabilize its structure. The temp. and time to heat the metal material 11 is predetermined by an experiment in reference to a kind, shape, size of the metal material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing distortion from a metal material having a predetermined length, particularly a rod-shaped material having a circular or non-circular cross section, when the material has distortion in the middle.

[0002]

2. Description of the Related Art Generally, prior to being processed into a mechanical element or a mechanical part, it is inspected whether or not the metal material has a distortion. Although the distortion is removed, the removal is typically performed as follows.

[0003] That is, as shown in FIG. 10, a metal material 1 is first fixed to two bases 2a fixed at a predetermined distance.
2b and rotated in the X direction of the peripheral surface. And
A distortion measuring device 3 is placed between the bases 2a and 2b, and the peripheral surface X of the metal material 1 is moved farthest from or close to the center line C by the distortion measuring device 3 so that the outermost deformation becomes the largest deformation. To find a location (maximum distortion location) S.

[0004] Next, as shown by a chain line Y in FIG. 11, the metal material 1 is rotated in the direction of the peripheral surface X, and the portion where the peripheral surface X is farthest from the center line C at the maximum strain point S is moved upward. Then, as shown in FIG. 12, a predetermined pressing force is applied to the metal material 1 by the press 4 to straighten the metal material 1 to remove the distortion from the metal material 1.

[0005]

However, the pressing force applied to the metal material 1 in the above-mentioned known strain relief method varies depending on the thickness and the material of the metal material 1, but reaches several hundred kilograms per unit square centimeter. Therefore, the press 4 itself is not only a very large-scale device, but also requires a large amount of energy to operate the press 4.

Accordingly, the present inventor has conducted intensive studies to find a method for removing a metal strain which does not require a large-scale device or a large amount of operating energy. After finding the fact, the present invention was completed. Therefore, an object of the present invention is to provide a method for removing distortion of a metal material which does not require a large-scale apparatus or a large amount of operating energy.

[0007]

According to the present invention, there is provided a method for removing a distortion from a predetermined length of a metal material having a distortion therein, the method comprising the steps of: After heating the inside curved surface of the portion where the heating is performed, a means of rapidly cooling the heated portion is employed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the most preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIG. For example, a columnar steel material 11 as a metal material is placed on the two installed bases 12a and 12b and rotated in the circumferential direction X. Then, the bases 12a, 1
2b, a distortion measuring device 13 is installed and the distortion measuring device 13
As a result, a position where the peripheral surface X of the steel material 11 is farthest or approached from the center line C is searched for as a portion B where the steel material 11 is most deformed (hereinafter, referred to as a deformation region).

The steel material 11 having the deformation region B is
As shown in FIG. 2, the deformation area B is not suddenly and discontinuously deformed in the middle thereof, so that the deformation area B has a distortion A between the non-deformation non-deformation areas D (in FIG. Is conceptually shown by adding an underline to the code A).

Next, the inner curved surface 11b of the deformation area B
The steel material 11 is rotated in the direction of the peripheral surface X so that the portion corresponding to the upper side faces upward, and as shown in FIG.
The heating / quenching device 14 is moved slightly above b.

The heating and quenching device 14 includes a heating means 15 such as a gas burner or a laser, and a quenching means 16. It runs along the direction. And the heating means 15 and the quenching means 1
6, energy is supplied from the separately provided heating medium source and quench medium source through the transmission means 18, 19.

Further, the heating / quenching device 14 is connected to a control device 21 via a signal line 20, and is controlled to operate on the rail 17 by a signal from a program input in advance. . The strain measuring device 13 is also connected to the control device 21 via a signal line 22, and starts measuring the strain of the steel material 11 by operating an actuator 23 according to a signal from the control device 21. The data is transmitted to the control device 21. The steel material 11 is conveyed onto the bases 12a and 12b by a separately installed conveying device (not shown) and is rotatable in the circumferential direction X. The operation command is controlled by the control device 21. Is transmitted to the transfer device or artificially transmitted from a worker.

The distortion removing method of the present invention is performed as follows by operating the heating / quenching device 14. First,
The heating and quenching device 14 is arranged such that the heating means 15 is located directly above the location where the strain A exists in the deformation region B.
Move and stop. Then, hot gas or laser is emitted from the heating means 15 to heat the deformation region B (see FIG. 3).

The degree of heating depends on the temperature at which the structure of the steel material 11 starts to move due to heat, that is, at the third transformation point, that is, when the temperature of the steel material is usually less than 400 ° C., the portion where the strain A exists expands. The steel material 11 is in a straight state.

The degree of the heating is determined in advance by experiments. That is, in relation to the type of the metal material 11 and the degree of the strain A, how much temperature and heat are applied to the metal material 11 to eliminate the strain A is grasped as experimental data. Then, the data is stored in the control device 21 and the temperature and the heat amount corresponding to the temperature and the heat amount are transmitted from the heating means 15 to the steel material 1.
The light is radiated to one deformation region B.

Next, when the heating of the steel material 11 is completed,
As shown in FIG. 4, the heating / quenching device 14 is moved so that the quenching means 16 of the device is located directly above the deformation region B. Then, a cooling medium such as cold water or cold air is blown out from the quenching means 16 to quench the deformed region B which has been heated up to that time, thereby fixing the tissue in that portion. Then, the steel material 11 is straightened, becomes parallel to the center line C shown by the dashed line in FIG. 2, and the distortion A is removed from the steel material 11.

As described above, in the method of the present invention, the metallic material 1
Although it is intended to remove the strain in the middle of the method 1 thermodynamically, the device used in this method is a device which has a requirement to simply heat or rapidly cool a metal material. It has the effect of not requiring large equipment and operating energy compared to technology, and as a result,
It can be said that this is a resource-saving and energy-saving method.

The present invention can be implemented by partially modifying the above-described embodiments as follows, as long as the effects of the present invention are not significantly impaired by following the fundamental technical concept thereof. (1) As the metal material, any metal material that needs to be strained and has a predetermined length to withstand heating can be used. (2) As the shape of the metal material, one having a circular cross section and a non-circular cross section such as a square or a hexagon as shown in FIGS. 5, 6 and 7 is used. A thin plate-like object is not used from the viewpoint that the thermal expansion effect cannot be used efficiently.

(3) For one metal material 11, FIG.
As shown in (1), a system may be provided in which a plurality of strain measuring devices 13 are prepared, strain is measured simultaneously at a plurality of locations, and strain is removed by one or a plurality of heating / quenching devices. (4) Further, as the metal material 11, a material having a bent portion 24 in the middle like a crankshaft shown in FIG. 9 and having a strain A in the non-refractive portion 25 also heated the portion where the strain A exists. At this time, the non-refractive portion 25
Can be used to the extent that longitudinal expansion is manifested (this material cannot be de-strained by the prior art).

[0020]

As described above in detail, the present invention has an excellent effect that the distortion can be removed from the metal material without using a large-scale device such as a press device or a large amount of operating energy. Can be.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing one embodiment of measuring strain of a metal material prior to carrying out the present invention.

FIG. 2 is a conceptual diagram illustrating a deformation region of a metal material.

FIG. 3 is a conceptual diagram showing a step of heating a metal material.

FIG. 4 is a conceptual diagram showing a step of rapidly cooling a metal material.

FIG. 5 is a perspective view showing one shape of a metal material.

FIG. 6 is a perspective view showing another shape of the metal material.

FIG. 7 is a perspective view showing still another shape of the metal material.

FIG. 8 is a conceptual diagram showing another aspect of the strain measurement method.

FIG. 9 shows another embodiment of the present invention.

FIG. 10 is a conceptual diagram showing a step of measuring a distortion of a metal material prior to the implementation of the conventional technique.

FIG. 11 is a conceptual diagram showing a preparation stage for removing a strain from a metal material in the conventional technique.

FIG. 12 is a conceptual diagram showing a process of removing distortion from a metal material in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Metal material 11b Inner curved surface 12a Base 12b Base 13 Strain measuring device 14 Heating / quenching device 15 Heating device 16 Rapid cooling device 17 Rail 18 Transmission device 19 Transmission device 20 Signal line 21 Control device 22 Signal line 23 Actuator A Distortion B Deformation area X Peripheral surface C Center line D Non-deformation area

Claims (2)

[Claims] 1. A method for removing a strain from a metal material of a predetermined length having a strain in the middle thereof, wherein the metal material (11) is provided.
A method of removing distortion of a metal material, comprising: heating an inner curved surface (11b) of a curved portion (B) receiving a strain (A) and then rapidly cooling the heated portion. 2. The method according to claim 1, wherein the heating of the metal material is performed at a temperature lower than a third transformation point of the metal.