JPS62270229A - Hot bulging device - Google Patents

Abstract

PURPOSE:To form a high hardness blank by arranging a cylindrical blank inside the die forming by overlapping a conductive inductor and insulating cooling part, then performing the high frequency heating of the inductor and applying a pressure to the inner side of the blank as well, etc. CONSTITUTION:A metal die 1 is formed by overlapping as well as winding in a coil shape the linear inductor 2 consisting of a conductive member and the linear cooling body 3 consisting of the insulating member of an alumina, etc. A hollow water passage 3a is provided on the cooling body 3 and a sensor 7 is arranged on a through hole 3b. A pipe blank 8 is arranged inside the die 1 and heated by passing a high frequency current to the inductor 2 from a high frequency generating device 5. In this case the external side of the heating part of the pipe 8 is abutted to the inner side of the die 1 and cooled and the excess bulging is checked. The sensor 7 detects the heating state, controlling the working conditions. Consequently the cylindrical blank of high hardness can be formed with a simple equipment.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a pipe processing device, and particularly to a hot pipe processing device that heats a part of a cylindrical material, applies pressure, and expands it. This invention relates to a bulge forming device.

[Prior Art] Conventionally, in one type of pipe processing apparatus for blow molding a part of a cylindrical material, for example, the cylindrical material is placed in a mold having a shape corresponding to the external shape of the molded product, and the cylindrical material is placed in a mold that has a shape corresponding to the external shape of the molded product. There is a bulge forming device that applies pressure to the inside of a cylindrical material to bulge a portion of it. In other words, the conventional bulge forming apparatus should be called a cold bulge forming apparatus.

[Problems to be Solved by the Invention] However, when attempting to bulge a cylindrical material made of a hard material such as high carbon steel using the cold bulge forming apparatus described above, extremely high pressure must be applied. It was necessary to add it to the inside of the cylindrical material, which had extremely poor workability and required large-scale equipment.

This invention was made to solve these problems, and aims to provide a bulge forming device that has good workability and can process a highly hard cylindrical material with relatively simple equipment. .

[Means for Solving the Problems] The present invention provides a metal molded product in which an inductor made of a conductive member and an insulating cooling part are overlapped, and the inner surface of the inductor is formed into a shape corresponding to the outer shape of a molded product. A mold is provided, a high frequency generator is connected to the inductor of the mold to flow a high frequency current, and a pressure intensifier is provided to apply pressure to the inside of the cylindrical material placed in the mold. A through hole is formed in the radial direction,
A sensor for detecting the condition inside the mold is provided outside the through hole.

[Function] According to the bulge forming apparatus according to the present invention, the inductor constituting the mold functions not only as a mold frame but also as a heating means when a high frequency current is passed therethrough by the high frequency generator. Furthermore, the cooling section that constitutes the mold functions not only as a mold frame but also as a cooling means for the inductor and the cylindrical material. Furthermore, the state of the cylindrical material that is being heated or expanded can be detected by a sensor placed in the cooling section.

[Embodiment] Hereinafter, the present invention will be explained in detail based on FIGS. 1 to 3.

FIG. 1 is a schematic diagram of an embodiment of a bulge forming apparatus according to the present invention.

In the drawings, 1 represents a mold of a bulge forming apparatus, and this mold 1 includes a linear inductor 2 made of a conductive material such as copper, and a linear cooling inductor 2 made of an insulating material such as alumina. The body 3 is wound into a coil shape so as to be adjacent to each other. That is, mold 1
has a structure in which a linear cooling body 3 formed in an almost identical shape is superimposed on a linear inductor 2 which is wound into a coil shape so that the winding parts do not contact each other (second
(see figure). A high frequency generator 5 is connected to both the upper and lower terminals of the linear inductor 2, so that a high frequency current can flow through the linear inductor 2. When a high-frequency current is passed through the coil-shaped linear inductor 2, the induced current is passed through the material placed inside the inductor and generates heat. In other words, the linear inductor 2 also acts as the heating section 4. On the other hand, the linear cooling body 3 constitutes a cooling section 6 as a whole. That is, in the bulge forming apparatus of the embodiment, the linear cooling body 3 is formed in a hollow shape, and the inside thereof is made into a passageway 3a.
A cooling water supply device (not shown) is connected to the upper and lower ends of the linear cooling body 3, so that cooling water can flow into the water passage 3a.

Further, a plurality of through holes 3b are formed in the middle of the linear cooling body 3, extending in the radial direction thereof.

As shown in FIG. 3, various sensors such as a non-contact displacement meter or a light thermometer are arranged at the radially outward position of each through hole 3b, and the material pipe 8 placed in the mold 1 Processing conditions such as temperature and degree of deformation can be detected through each of the through holes 3b. However,
In this bulge forming apparatus, the pressure timing and heating time during bulge forming are controlled by signals from the sensor 7.
Various controls such as cooling rate can be performed. Note that this bulge forming apparatus is provided with a pressure intensifier so that pressure can be applied to the inside of the material pipe 8.

Next, a bulge forming method performed by this bulge forming apparatus will be explained.

First, the material pipe 8 is placed in the mold 1 as shown in the third figure. Next, a high frequency current is passed through the mold 1 by the high frequency generator 5 to generate an induced current in the raw material pipe 8, and the raw material pipe 8 is heated by this induced current to just below the melting point. This reduces the deformation resistance of the heated portion of the material pipe 8. Also, at this time, cooling water is flowed through the passageway 3a of the linear cooling body 3 constituting the cooling section 6 to prevent the linear inductor 2 from overheating. Next, or while heating, pressure is applied to the inside of the material pipe 8 by a pressure intensifier, and a part (heated portion) of the material pipe 8 is expanded.

To explain the expansion process of the raw material pipe 8, the outer periphery of the heated portion of the raw material pipe 8 comes into contact with the inner periphery of the mold 2. Due to this contact and further cooling by the cooling water flowing through the passageway 3a of the linear cooling body 3, further expansion of the material pipe 8 is prevented. In this way, the bulge forming of the material pipe 8 is completed.

During this bulge forming, the heating state and swelling state of the material pipe 8 are detected, and this detection signal is sent to the high frequency generator 5.
, a cooling water supply/discharge device, and/or a pressure booster, which determine and control conditions such as temperature and pressure during bulge forming of the material pipe 8.

According to the bulge forming apparatus of this embodiment, the mold 1 functions not only as a mold frame but also as a heating means, so that the bulge forming of the highly hard material pipe 8 can be easily performed with a simple configuration. become. Further, since the sensor 7 is provided to detect the state of the raw material pipe 8 during heating or expansion and to control the processing conditions, bulge forming can be performed appropriately and efficiently. Furthermore, since it has the cooling part 6, while the linear inductor 2 is energized, the water passage 3
By flowing cooling water through a, melting of the linear inductor 2 can be prevented. Moreover, since the material pipe is hardened by the cooling water, excessive force is not applied to the mold 1, and the mold 1 is not adversely affected.

Note that the present invention is not limited to such embodiments, and various modifications are possible. For example, the mold 1 is constructed by forming each of the heating section 4 and the cooling section 6 from plate-like members and stacking them alternately.

The through holes 3b may be provided in the plate-shaped cooling section.

Moreover, instead of flowing the cooling water through the linear cooling body 3, the linear inductor 2 may be formed into a hollow shape, and the cooling water may be made to flow therein. Further, the object of bulge forming is not limited to the material pipe 8, but may also be a cylindrical material with one end closed, for example. In short, any material that can apply pressure to the inside of the material is sufficient.

[Effects of the Invention] As is clear from the above description, according to the present invention, an inductor made of a conductive member and an insulating cooling part are overlapped, and the inner surface thereof corresponds to the outer shape of the molded product. A mold is provided to form the shape, a high frequency generator is connected to the inductor of this mold to flow a high frequency current, and a pressure intensifier is provided to apply pressure to the inside of the cylindrical material placed in the mold. With,
A through hole is formed in the cooling section in the radial direction, and a sensor is provided outside the through hole to detect the condition inside the mold. 6. It also allows for easy expansion molding.

Since the state of the cylindrical material during heating and expansion can be detected by a sensor, bulge forming can be performed appropriately and efficiently by controlling the temperature and pressure during processing.

Furthermore, while the inductor is energized, the cooling section can prevent the inductor from melting.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an embodiment of a bulge forming apparatus according to the present invention. 2 is a schematic configuration diagram of an embodiment of the bulge forming apparatus shown in FIG. 1, and FIG. 3 is a schematic plan view of the bulge forming apparatus according to the present invention. 1...Mold, 2...Inductor, 3b...Through hole, 4...Heating part, 6...Cooling part, 7...Sensor, 8...・Material pipe.

Claims (1)

[Claims] A mold includes an inductor made of a conductive material and a cooling part made of an insulating material at least on the surface, the inner surface of which is formed into a shape corresponding to the outer shape of the molded product, and a high-frequency current is passed through the inductor and cooled inside the mold. The cooling section is equipped with a high frequency generator for heating a cylindrical material placed in the cylindrical material, and a pressure intensifier for applying pressure to the inside of the cylindrical material to expand the heated portion of the cylindrical material. A water passage through which cooling water flows is formed, and a through hole is formed in the radial direction of the mold, and a sensor that can detect the state of the cylindrical material through the through hole is arranged outside the through hole. A hot bulge forming device characterized by: