JPS5985341A - Heating controlling method of electric upsetter - Google Patents

Abstract

PURPOSE:To prevent forming goods from being cracked due to overheating by measuring electric power supplied to a plank material and a push-in quantity of the blank material, and controlling electric power so that a value of electric power/push-in quantity per unit time and electric power/unit volume becomes a reference value, when manufacturing upsetter forming goods by a direct electric conduction heating system. CONSTITUTION:A blank material 1 is pressed against a anvil 2 by an hydraulic cylinder 3, also the lower part is held by an electrode 4, and the blank material 1 is subjected to electric conduction and is softened by the anvil 2 and the electrode 4, by which forming is executed. In this case, voltage, a current, a power factor and a push-in quantity of the blank material 1 are measured by a measuring part 10, its result is inputted to an operating part 11, electric power/unit volume is derived by calculating electric power per unit time and a push-in volume, and it is inputted to a comparing part 12. In the comparing part 12, a reference value C set in advance is compared with the electric power/unit volume, this value is fed back to voltage, the voltage is controlled so as to become C=electric power/unit volume, by which forming goods are prevented from being cracked due to overheating.

Description

[Detailed description of the invention] The present invention relates to a method for controlling heating of an electric upsetter.

It is known from experience that when producing upsetter molded products using the direct current heating method, if a part of the molded product is extremely overheated for some reason, cracks tend to occur in some parts of the molded product. ing. This is thought to be because some grain boundaries in the molded product approach a molten state due to the rise in temperature of the molded product, and begin to become brittle.

Currently, during upsetter molding, the contact resistance between the upper anobile and the material or the lower electrode and the material changes due to changes in the contact area and deposits on the surface, so it is necessary to maintain a constant heating state for each molded product. That is difficult. In order to avoid the influence of variations in heating conditions, the forming force to the material is applied by a hydraulic cylinder, and the feather pushing speed is made to vary slightly depending on the resistance of the upsetter molded product. However, in reality, the worker determines the shape of the molded product from all angles.
The pressure or current is determined, and the pressure or flow rate to the hydraulic cylinder is adjusted to obtain the best shape.

For example, Figures 1 (A), (B), and (C) are diagrams of the principle of a direct energization type upsetter, in which a material 1 is pushed against an anvil 2 by a hydraulic cylinder 3, and its lower part is gripped by a lower electrode 4. In this state, a current is passed between the duckling 2, the electrode 4, and the material 1 to directly heat the material 1. The heated part 1 is pushed from below by the hydraulic cylinder 3, so the heated part deforms as shown in Figure 1 (B), and then becomes the shape shown in Figure 1 (C), completing the molding. 1. In this case, as mentioned above, cracks tend to occur in some parts of the molded product due to overheating, but the location of the cracks is not constant in the height direction and varies from molded product to molded product, so it is difficult to determine whether the molding is good or not. It was difficult to obtain goods.

The present invention was proposed in view of the above circumstances, and an object of the present invention is to provide a heating control method for an electric upsetter that reliably prevents cracking of the molded product caused by overheating in the electric upsetter and obtains a good molded product. shall be.

The heating control method for an electric upsetter according to the present invention is an electric upsetter that applies electricity between an anvil and an electrode holding a part of a material, and presses the material between the anvil and the electrode while directly heating the material to form the material. , measure the power supplied to the material and the pushing amount of the material, calculate the power/pushing amount per unit time or the power/unit volume, and make sure that this value is equal to a preset reference value. It is characterized by controlling the above-mentioned electric power.

An embodiment of the present invention will be explained in detail based on FIG.

FIG. 2 is a schematic flowchart for explaining a heating control method for an electric upsetter according to an embodiment of the present invention.

In FIG. 2, 10 is a measurement section, 1 is a calculation section, and 12 is a comparison section. In FIG. 2, a measuring section 10 measures, for example, voltage, current, power factor, and material push-in amount, and the measurement results are input into a programmer section 11. In the calculating section 11, the frost, force, and pushing volume per unit time are calculated by tl'N to obtain electric power/unit volume, and this is input to the comparing section 12. The comparator 12 compares a preset reference value C with frost, force/unit volume, feeds back this value to, for example, 1M force/unit volume, and controls the voltage so that C=1M force/unit volume.

Note that the amount of heat input may be used for the electric power liner according to the above embodiment, or the amount of push-in of 9 times per unit time per unit volume may be used. In this case, the same result can be obtained by appropriately setting the reference value C, taking into account the constant or the influence of the material diameter.

By controlling the above-mentioned C = force/unit volume, it is possible to keep constant the heating conditions that varied during engraving such as contact resistance and other elements, and the overheating of the absetter molded product is reduced to 1. - It is possible to prevent molded products from cracking due to overheating.

In the example described in 2, when controlling the amount of heat input il+ so that the reference value C=power/unit volume, for example, a simple slide transformer type was used to control the voltage by 1 degree. Instead, for example, a thyristor or the like may be used and the phase of applying the trigger pulse may be controlled so that C=power/unit volume, thereby keeping the heat input constant.

Since the present invention is configured as described above, it measures power and heat input per unit time and per unit volume, and measures power/unit volume, force/pushing amount, heat input/unit volume, and 'g+, pressure x By adjusting the current/unit pressure etc. to be equal to the reference value C, the amount of heat entering the molding part is kept constant with respect to the volume of the pressed part, and this makes the unheated part warm. By keeping the heat b-' constant, cracks in the molded product caused by overheating can be reliably prevented, resulting in excellent molding and shaping.

In short, according to the present invention, an electric upsetter is provided in which electricity is applied between an anvil and a pole holding a part of a material, and the material is pushed between the anvil and the upper power supply 4 while directly heating the material to form the material. , %', force supplied in the above-mentioned cumulative month and the pushing amount of the above-mentioned material are measured, and '~power/pushing amount per unit time or %, force/unit volume is calculated, and this value is set in advance. To provide a heating control method for an upsetter that reliably prevents cracking of a molded product caused by overheating and obtains a good molded product by controlling the above-mentioned peak and force so that they are equal to the reference values set. Therefore, the present invention is extremely useful industrially.

[Brief explanation of the drawing]

Figures 1 (A), (B), and (C) are for explaining the principle (9) of a direct current absorber, respectively, and Figure 2 is for explaining a heating control method for a frost and air absorber according to a practical example of the present invention. FIG. 2 is a schematic flowchart diagram. DESCRIPTION OF SYMBOLS 1... Material, 2... Anvil, 3... Hydraulic cylinder, 4... Electrode, 10... Measuring part, 11... Act 1 part, 12... Comparing part.

Claims (1)

[Claims] Electricity is applied between the anvil and an electrode that grips a part of the moon,
In an electric upsetter that presses and shapes the material between the anvil and the electrode while directly heating the material, measuring the electric power supplied to the material and the amount of pushing of the material,
'Electric power/push per hour of coronation1. Alternatively, the electric power/unit volume is calculated, and the electric power is controlled so that this value becomes equal to a preset reference value.