JPS6343722A - Press straightening method for bar steel stock - Google Patents

Abstract

PURPOSE:To improve the straightening accuracy and working efficiency by finding the necessary press load, etc., based on the relation of the press load found in advance and residual displacement measure and acting this press load, etc., on a bar steel stock. CONSTITUTION:A distance sensor 5 is set up at the center position between anvils 3, 3 of a straightening machine 2 and a pressure sensor 7 on the ram 6 for pressing a straightening piece 4 as well. A p-delta diagram is made in advance by using the distance sensor 5 and pressure sensor 7 on a bar stock 1. The load removal start point Q of each straightening point is found in the p-delta diagram after reading the straightening amount and straightening point of the bar stock 1 and the necessary press displacement measure or press load is read. The straightening is then performed by acting this displacement measure or load on the bar stock 1. Since the work can be performed in short time by one worker the streightening accuracy and working efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for press straightening, for example, A.

(Conventional technology) For example, when straightening a bar material, measure it in advance.

The bar is straightened based on the bending value, and conventionally this has been done by applying a press load to the bar H while an operator visually observes the straightening situation.

In addition, in recent years, a special machine has been developed that enables automatic measurement and automatic correction of curves.

(Is it an invention or a problem to be determined, Therefore, there is a problem that the correction accuracy and the distance 111 required for correction are cammed.

Also, the latter method requires a dedicated mechanical device 1゛π゛,
Moreover, the control device and stem for this are enormous, and the equipment is expensive.Secondly, there are problems in terms of installation space, etc.

The present invention has been made in view of such problem 6' Aij, and uses an existing press straightening machine to always perform press straightening of bar + 1 with constant straightening accuracy and straightened intercostals, regardless of the skill level of the operator. ? ) presents a press straightening method (,1j-
There is something to be said for.

(T-IC that does not solve the problem) In the press straightening method C5F of steel bars according to the present invention, the relationship between the press load applied to the straightening target and the residual angle = lt method is determined in advance, The gist of this method is to obtain a required press displacement dimension or press load from the above relationship based on the dimension to be straightened, and to apply the press displacement dimension or press load to the material to be straightened.

That is, when press straightening a material to be straightened, the present invention establishes a correlation between the press load and the residual displacement dimension based on the mechanical properties of the material to be straightened, in the relationship between the press load necessary for press straightening and the straightening displacement. The correction principle of the method of the present invention will be explained based on FIGS. 1 and 2.

For example, when the bar 1 is supported with a span and a press load P is applied to the center of this span L, the relationship between the press load P and the displacement δ of the bar 1 (hereinafter referred to as the rp-δ diagram) is It will look like Figure 2.

In FIG. 2, the area between A and B is a non-contact area, and the press load P is not acting on the bar 1 in this area. When a press load P is applied to the bar 1, the press load P and the displacement δ increase in direct proportion between the elastic bending regions B and C, and when the press load P is removed, the displacement δ returns to the original value. However, if a press load P is further applied beyond this area, C-
If the displacement δ is reached between the plastic bending regions D, even if the press load P is removed, the displacement δ will not return to its original state. displacement remains.

That is, δ in span L. If there is a displacement of
The said δ. Appropriate correction can be achieved by applying a displacement of δ'' from a direction 180 degrees opposite to the displacement of and then unloading.

In FIG. 2, 0-E is a straight line parallel to B-C, Q is the unloading start point, and Q~0 is the unloading curve.

(Example) The method of the present invention will be explained in detail below based on the attached drawings starting from FIG.

First, FIG. 3 shows the equipment necessary to carry out the method of the present invention.

That is, in FIG. 3, 2 is a straightening machine, and this straightening machine 2 has two anvils 3.3 arranged at a predetermined interval, and is arranged at the center position on the opposite side of these anvils 3.3. The device is equipped with a straightening piece 4 which is attached to the anvil 3.3, and straightens the bar 1 positioned between the anvil 3.3 and the straightening piece 4 by moving the straightening piece 4 toward the anvil 3.3 and pressing it. It is.

Therefore, in order to carry out the method of the present invention, a distance sensor 5 is installed at the center position between the anvils 3 and 3 of the straightening machine 2, and a pressure sensor 7 is installed on the pressing ram 6 of the straightening piece 4, as described below. Do as you will.

In addition, 8 in FIG. 3 is a rotating and holding device for the bar 1.

First, the correction point and correction amount of the bar 1 whose bending was measured in the previous process are read.

Then, the unloading start point Q at each straightening point is determined using the "P-δ diagram" determined in advance by the distance sensor 5 and pressure sensor 7 for the bar 1, and the unloading start point Q is determined for each straightening point in turn. Straightening is performed by applying a press load P.

For example, in the example shown in Figure 4, if the 0 point is corrected by δ1 with the bending span L, the result will be as shown by the dashed dotted line in the figure, and then if the 0 point is similarly corrected by δ2 with the bending span L, the result will be as shown by the dashed double dot line in the figure. It becomes almost straight.

After the correction is performed as described above, the bending is measured again, and the same operation as above is carried out for the portions where the bending value is above the allowable value.

FIGS. 5 and 6 show the results of correction by the method of the present invention.

The bar 1 used in this implementation has a diameter of 152 m1 + φ and a length of 9
．． The length was 48 m, and the material was a round steel bar equivalent to SCM445, and the span L was 700 m.

The vertical axis in FIGS. 5 and 6 indicates the amount of bending of the bar 1 at every 45° position from the reference position, and the horizontal axis indicates the position of the bar 1 in the longitudinal direction. FIG. 5 shows the bend before correction, and FIG. 6 shows the bend after correction. The position indicated by the arrow in FIG. 5 is the correction point.

The table below shows each residual displacement amount δ determined from the “P-δ diagram”.
. Press load P and actual residual displacement amount δ corresponding to . shows.

As is clear from FIGS. 5 and 6, it was confirmed that the method of the present invention allows for highly accurate correction. The straightening time in this case was 0.9 hours.

(Effects of the Invention) As explained above, in the press straightening method for bars and steel materials according to the present invention, the relationship between the press load applied to the material to be straightened and the residual displacement dimension is determined in advance, and the dimension to be press straightened is determined in advance. This method calculates the required press displacement dimension or press load from the above relationship based on the above relationship, and applies the press load to the material to be straightened, so it can be done in a short time by one operator using an existing press straightening machine. Large and highly accurate correction can be performed.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the correction principle of the method of the present invention, Figure 2 is a diagram showing an example of a "P-δ diagram" used in the method of the present invention, and Figure 3 is a press used in the method of the present invention. FIG. 4 is a schematic plan view of the straightening machine, FIG. 4 is an explanatory diagram of the method of the present invention, and FIGS. 5 and 6 are curved line diagrams showing an example of the results of the method of the present invention. I is a bar, 3 is an anvil, 4 is a correction piece, 5 is a distance sensor, and 7 is a pressure sensor.

Claims (1)

[Claims] (1) Determine the relationship between the press load applied to the material to be straightened and the residual displacement dimension in advance, determine the required press displacement dimension or press load from the above relationship based on the dimension to be press straightened, and calculate the press displacement A method for press straightening a steel bar material, characterized by applying dimension or press load to the material to be straightened.