JPH08187543A - Device for heating and cutting bar material for forging - Google Patents

Abstract

PURPOSE: To restrain the unevenness of heating temp. of a bar material regardless of the length of an end material and at the same time, to prevent the loss of heating energy, in a heating and cutting device for obtaining a billet for forging by heating the long bar material and successively, cutting to a prescribed length. CONSTITUTION: In the case of obtaining the billet 7 for forging by heating the long bar material 6 for forging while passing through a high frequency induction bar heater 1 and cutting the tip part of the bar material 6 projected by a prescribed distance from this outlet side to the prescribed length, at the cutting cycle needed to the treatment of the end material 8, the length of the end material 8 is obtd. and a correcting voltage having the intensity according to this length is impressed to the bar heater 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for forging by cutting a long bar material for forging through a heating furnace and cutting the tip of the bar material projecting a predetermined distance from the outlet side of the heating furnace to a predetermined length. The present invention relates to a heating cutting device for bar material for forging, which is adapted to obtain a billet.

[0002]

2. Description of the Related Art FIG. 4 is a layout diagram of a forging press line, which has a high frequency induction heating coil and a bar heater 1 for heating a long bar material passing through the coil.
A hot shear 2 arranged at the outlet side of the bar heater 1 to cut the tip of the bar material heated by the bar heater 1 into a forging billet having a predetermined length, and a bar arranged at the inlet side of the bar heater 1 A material supply device 3 for supplying a long bar material to the heater 1 (see above, for example, JP-A-4-71746), a forging device 4 for forging a forging billet into a predetermined shape, a bar heater 1, a hot shear. 2 and a control device 5 for controlling the bar material supply device 3.

The processing of the bar material in the bar heater 1 and the hot shear 2 will be described with reference to FIG. 1. The bar material 6 inserted in the center of the bar heater 1 and sent forward.
Is projected for a predetermined distance from the outlet side of the bar heater 1, and is cut into a billet 7 by the cutting blade (movable side) 2a and the cutting blade (fixed side) 2b of the hot shear 2 at regular intervals. Although the scrap 8 is generated after the final cutting billet 7a, if the length is a, the length of the bar member 6 is b, the cutting length is c, and the number of cuts per bar member is n _0. , A
= B−c × n ₀ . In addition, 6a is a next bar material.

2 and 3, the processing of the bar material will be described in more detail. In the normal cutting cycle, as shown in FIG. 2, the bar material 6 in the bar heater 1 is fed, for example. It is made to project from the outlet of the bar heater 1 by the roller and comes into contact with a stopper (not shown) to stop (Fig. 2 (a)). Next, at the same time when the stopper escapes, the cutting blade 2a descends to cut the tip of the bar material 6 into a predetermined length (FIG. 2 (b)), and subsequently the pushback rod 9
Thereby, the bar material 6 is returned into the bar heater 1 again (FIG. 2 (c)).

In the cutting cycle that requires the processing of the scrap material, as shown in FIG. 3, the bar material 6 is similarly projected from the outlet of the bar heater 1 by the feed roller and abuts against a stopper (not shown) to stop (FIG. 3). (A)). Next, at the same time when the stopper escapes, the cutting blade 2a descends and the tip of the bar material 6 is cut into a predetermined length (FIG. 3 (b)).
However, here is the difference from the normal cycle shown in FIG.
This is the point at which the scrap 8 which is insufficient in the required length is left and the next bar 6a continues behind the scrap 8.

Next, after the next bar material 6a is advanced and the scrap material 8 is removed from the tip of the next bar material 6a (see FIG. 3).
(C)), the next bar material 6a by the pushback rod 9
Is returned to the inside of the bar heater 1 (FIG. 3 (d)), and thereafter the normal cutting cycle is repeated.

By the way, in a normal cutting cycle, the bar member 6 (and the next bar member 6a) is advanced by a predetermined distance from a predetermined position in the bar heater 1 until it comes into contact with the stopper.
After cutting the length b of the tip, it is returned to a predetermined position in the bar heater 1 again. As a result, the bar material 6 (the next bar material 6a
Also, () is heated in the bar heater 1 while intermittently advancing by the cutting length b of the billet 7 in each normal cutting cycle.

On the other hand, in the cutting cycle which requires the processing of the scrap material, the cutting material 8 of the length a is removed in addition to the cutting of the length b, which results in the cutting cycle which requires the processing of the scrap material. Further, the next bar material 6a advances by a length (= a + b) obtained by adding the length a of the end material 8 to the cutting length b of the billet 7. In other words, when a cutting cycle that requires processing of the scrap material comes around, the next bar material 6a advances in the bar heater 1 by a length a of the scrap material 8 longer than usual.

Therefore, the portion that was inside the bar heater 1 and the bar heater 1 before the cutting cycle that requires the processing of scrap materials.
There is a difference in the in-core time in the lengthwise direction of the next bar 6a from the portion located outside, which appears as uneven heating temperature. Therefore, conventionally, a constant correction voltage set in advance (set higher than a normal applied voltage) is applied to the bar heater 1 during a cutting cycle that requires scrap material treatment to stabilize the heating temperature of the bar material. It was

FIG. 6 is a flow chart showing the heating and cutting operation of the bar material described above. In step S1, the bar material 6 is projected from the outlet of the bar heater 1 by a predetermined distance (see FIG. 2 (a)). ), The tip of the bar material is cut into a predetermined length in step S2 (see FIG. 2 (b)), and pushed back in step S3 (see FIG. 2 (c)).

Then, in step S4, it is judged whether or not the scrap material processing is required after the next cutting. this is,
When the original length of the bar material is b, the cutting length of one time is c, and the number of times of cutting up to that time is n, the length of the remaining bar material is b−c × n, and (b− When c × n) ≧ c, it is determined that the mill ends are not required and the normal cutting cycle is repeated, and when (b−c × n) <c, it is determined that the mill ends are required and step S5 is performed. Then, a predetermined correction voltage is applied instead of the voltage applied to the bar heater 1 so far. Then, after the corrected voltage is returned to the original applied voltage, the cutting cycle shown in FIG. 3 which requires the scrap processing is executed in step S6.

[0012]

By the way, the length a (a = b−c × n ₀ ) of the end material is actually a different value for each bar material because the length b of the bar material is not constant. However, conventionally, the length of the scrap material is temporarily considered to be a constant value a _0, and the correction voltage is preset to a constant value corresponding to a _0. Therefore, when the actual length of the scrap material is larger than a _0. Causes insufficient heating, and when it is smaller than a _0, excessive heating occurs, and the heating temperature of the bar material varies. In many cases, the length a ₀ of the end material is set to a large _value in order to prevent the billet from being insufficiently heated, so that heating energy is lost due to excessive heating.

The present invention has been made in view of the above problems of the prior art. In the above-described forging bar material heating and cutting apparatus, the variation in the heating temperature of the bar material is irrespective of the length of the scrap material. The purpose is to suppress and at the same time prevent loss of heating energy.

[0014]

According to the present invention, a heating furnace for heating a long forging bar material while intermittently feeding it, and a tip of the bar material that passes through the heating furnace and projects a predetermined distance from the outlet side are provided. In a heating cutting device for a bar material for forging provided with a cutting device for cutting to a length, and a control means for controlling the thermal energy applied to the bar material by the heating furnace, the control means has the above-mentioned feature in a cutting cycle requiring a scrap material treatment. It is characterized in that the thermal energy is corrected according to the length of the scrap material, preferably, the heating furnace is an induction heating furnace, and the control means controls the voltage applied to the induction heating furnace. In addition, the heating and cutting device is characterized by including a pushback device for returning the cut bar material to a predetermined position of the heating furnace.

[0015]

In the above heating and cutting apparatus, the thermal energy applied to the bar material by the heating furnace is corrected in accordance with the length of the scrap material during the cutting cycle requiring the scrap material treatment. Since the heat energy of a commensurate size is applied to the bar material in the bar heater, it is possible to suppress the variation in the heating temperature of the bar material, which has been caused by the change in the length of the scrap material in the related art. In addition, loss of heating energy can be prevented.

[0016]

EXAMPLES In the examples of the present invention, a bar heater having a built-in high frequency induction heating coil is used as a heating furnace, and a hot shear having upper and lower cutting blades is used as a cutting device. 1 is the same as the conventional example described with reference to FIGS. 1 to 4, and hereinafter, the flow chart of FIG.
-Examples of the present invention will be described with reference to FIG.

In this embodiment, as shown in FIG.
In step S11, the bar material 6 is projected from the outlet of the bar heater 1 by a predetermined distance (see FIG. 2 (a)), and in step S12, the tip of the bar material 6 is cut into a predetermined length (see FIG. 2 (b)). In step S13, the cut bar material 6 is pushed back into the bar heater 1 (see FIG. 2).
(C)).

In step S14, it is determined whether or not the scrap material processing is required after the next cutting. This means that when the original length of the bar material is b, the length of one cut is c, and the number of cuts up to that time is n, the length of the remaining bar material is b-c.
Xn, when (b−c × n) ≧ c, it is determined that the mill ends are not required, and the normal cutting cycle is repeated. When (b−c × n) <c, the mill ends are treated. If it is determined to be necessary, the process proceeds to step S15.

In step S15, the length a (a
= B−c × n ₀ ), and in step S16, a correction voltage having a magnitude corresponding to the length a of the end material is calculated. For example, the correction voltage V is a function of the length a of the scrap 8 (V
= F (a)) is input to the control device 5 in advance, and the value of a obtained in step S15 is substituted into this to obtain the correction voltage V. The above function is selected so that thermal energy of a size commensurate with the length of the end material 8 is given to the bar material 6a in the bar heater 1.

Subsequently, in step S17, the correction voltage V obtained by the above calculation is applied in place of the voltage applied to the bar heater 1 so far. Then, after returning the correction voltage to the original applied voltage, in step S18, as shown in FIG.
The cutting cycle that requires the processing of the scrap material is executed.

[0021]

According to the present invention, a heating furnace that heats a long forging bar material while intermittently feeding it, and a tip of the bar material that passes through the heating furnace and projects a predetermined distance from the outlet side have a predetermined length. In a heating and cutting device for a bar material for forging provided with a cutting device for cutting the bar material and a control means for controlling the heat energy applied to the bar material by the heating furnace, the variation in the heating temperature of the bar material is suppressed regardless of the length of the mill ends. At the same time, the loss of heating energy can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a heating cutting operation and a scrap processing operation.

FIG. 2 is an explanatory diagram of a normal cutting cycle.

FIG. 3 is an explanatory diagram of a cutting cycle that requires processing of mill ends.

FIG. 4 is a layout diagram of a forging press line.

FIG. 5 is a flowchart for explaining an example according to the present invention.

FIG. 6 is a flowchart for explaining a conventional example.

[Explanation of symbols]

 1 Bar Heater 2 Hot Shear 2a, 2b Cutting Blade 6 Bar Material 6a Next Bar Material 7 Forging Billet 8 End Material 9 Pushback Rod

Claims (3)

[Claims] 1. A heating furnace for heating a long forging bar material while intermittently feeding it, and a cutting device for cutting the tip of the bar material passing through the heating furnace and protruding a predetermined distance from the outlet side to a predetermined length. In a heating and cutting apparatus for bar material for forging provided with a control means for controlling the heat energy applied to the bar material by the heating furnace, the control means controls the heat energy to the length of the end material in a cutting cycle that requires processing of the scrap material. A heating and cutting device for a bar material for forging, which is corrected according to 2. The apparatus for heating and cutting a bar material for forging according to claim 1, wherein the heating furnace is an induction heating furnace, and the control means controls the voltage applied to the induction heating furnace. . 3. The heat cutting device for bar material for forging according to claim 1, further comprising a pushback device for returning the cut bar material to a predetermined position of a heating furnace.