Patent Description:
In the related art, a forming apparatus is known, which performs forming by supplying gas into a heated metal pipe material to expand the metal pipe material. For example, a forming apparatus disclosed in <CIT> includes an upper die and a lower die which are in a pair, a holding unit which holds a metal pipe material between the upper die and the lower die, and a gas supply unit which supplies gas into the metal pipe material held by the holding unit. In this forming apparatus, the metal pipe material is expanded by supplying gas into the metal pipe material in the state where the metal pipe material is held between the upper die and the lower die, and it is possible to form the metal pipe material in the shape corresponding to the shapes of the dies.

<CIT> discloses a hydroforming unit and was used as a basis for the preamble of claim <NUM>. Specifically, the hydroforming unit comprises a mould that can be opened and sealing arrangements for sealing the ends of a tube-formed blank placed in the mould, wherein each one of the sealing arrangements comprises a ring with a thin wall that fits into the inner surface of the tube, and a plug that can be displaced in an axial direction mounted axially inside of the ring, and an arrangement for initially drawing the plug outwards to put the ring under elastic tension against the inside of the tube-formed blank so that the plug and the ring together form a seal.

<CIT> discloses an apparatus and a method to form a workpiece into a useful product using a pressurized fluid, also termed as "hydroforming". The workpiece may be a tube or may be one or a plurality of sheets of a material. The apparatus has a chamber adapted to contain a quantity of a fluid, a hydroforming means positioned within the chamber, and means for substantially immersing the workpiece in the fluid before, during and after the hydroforming operation. Dies enclose the workpiece and provide a cavity of desired shape against which the workpiece is expanded by the pressurized fluid. The chamber may be open or closed to the atmosphere during operation and the fluid temperature and/or level may be controlled.

Here, preliminary forming such as bending is performed in advance before the metal pipe material is expanded. In addition, cutting may be performed on the expansion-formed metal pipe. In a case where a series of the preliminary forming, the forming, and cutting are continuously performed on the metal pipe material, if a gas supply unit is disposed on a path in which the metal pipe material is transported from a preliminary forming apparatus to a forming apparatus, the gas supply unit becomes an obstacle when the metal pipe material is transported. Accordingly, a method is considered in which the gas supply unit is moved so as to be largely separated from the main body portion of the forming apparatus when the metal pipe material is transported. In this case, there is a problem in that a size of a moving mechanism for moving the gas supply unit increases. In addition, time for moving largely the gas supply unit is required, and there is a problem that a forming cycle time of the metal pipe is lengthened. In a case where the gas supply unit is disposed on a path in which the formed metal pipe is transported from the forming apparatus to a cutting device, similar problems may occur.

An object of the present invention is to provide a forming system in which a gas supply unit of a forming apparatus does not obstruct a metal pipe material which is transported from a preliminary forming apparatus to a forming apparatus and a metal pipe which is transported from the forming apparatus to a cutting device.

According to an aspect of the present invention, there is provided a forming system which expands and forms a metal pipe in a die, as set forth in claim <NUM>. According to another aspect of the present invention, there is provided a forming system which expands and forms a metal pipe in a die, as set forth in claim <NUM>. Preferred embodiments of the present invention may be gathered from the dependent claims.

According to the forming system, the gas supply unit is provided so as not to be disposed on the first straight line which connects the preliminary forming apparatus and the main body portion in a plan view and the second straight line which connects the cutting device and the main body portion in a plan view. Accordingly, in a case where the preliminary formed metal pipe material is transported from the preliminary forming apparatus to the forming apparatus, the gas supply unit is not disposed on the first straight line which is a portion of a transport path of the metal pipe material. Therefore, the gas supply unit of the forming apparatus does not obstruct the metal pipe material which is transported from the preliminary forming apparatus to the forming apparatus. In addition, in a case where the formed metal pipe is transported from the forming apparatus to the cutting device, the gas supply unit is not disposed on the second straight line which is a portion of the transport path of the metal pipe. Accordingly, the gas supply unit of the forming apparatus does not obstruct the metal pipe which is transported from the forming apparatus to the cutting device. Therefore, according to the forming system, since it is not necessary to increase a size of a moving mechanism for moving the gas supply unit and largely move the gas supply unit, the gas supply unit does not obstruct the metal pipe material which is transported from the preliminary forming apparatus to the forming apparatus, and the metal pipe which is transported the forming apparatus to the cutting device.

In addition, in a case where horizontal directions orthogonal to each other with respect to a center of the forming apparatus are the first direction and the second direction, the preliminary forming apparatus and the cutting device may be disposed on one side in the first direction from the forming apparatus, the preliminary forming apparatus may be disposed on one side in the second direction from the forming apparatus, and the cutting device may be disposed on the other side in the second direction from the forming apparatus.

According to the forming system, the preliminary forming apparatus, the forming apparatus and the cutting device are not disposed in a row in the horizontal direction, and, for example, can be disposed in a V shape, a U shape, or the like in a plan view. Accordingly, compared to a case where the preliminary forming apparatus, the forming apparatus and the cutting device are simply disposed in a row, it is possible to decrease a site area of the forming system.

Here, a pair of the gas supply units are provided in the second direction in a state where the center of the forming apparatus is interposed between the gas supply units. In this case, for example, when the metal pipe material is transported from the preliminary forming apparatus to the forming apparatus, it is possible to dispose the preliminary forming apparatus with respect to the forming apparatus such that the pair of gas supply units which are disposed in the forming apparatus do not interfere with the metal pipe material.

In addition, the forming system may further include a handling device which transports the metal pipe material from the preliminary forming apparatus to the forming apparatus, and the handling device may be disposed on the one side in the first direction from the forming apparatus, and may be disposed between the preliminary forming apparatus and the cutting device. In this case, it is possible to dispose the handling device which transports the metal pipe material such that the transported metal pipe material does not interfere with various components such as the gas supply unit of the forming apparatus.

In addition, the forming system may further include a wall which is provided on the other side in the first direction from the forming apparatus, and a gas supply source which is provided on the other side in the first direction from the wall and supplies the gas to the gas supply unit. In this way, since the wall is disposed on the sides opposite to the preliminary forming apparatus and the cutting device in the state where the forming apparatus is interposed therebetween, it is possible to decrease a distance between the wall and the forming apparatus in the first direction. Accordingly, it is possible to further decrease the site area of the forming system.

Moreover, in a case where horizontal directions orthogonal to each other with respect to a center of the forming apparatus are the first direction and the second direction, the gas supply unit may be separated from the center of the forming apparatus and may be provided in the first direction, and the preliminary forming apparatus, the forming apparatus, and the cutting device may be disposed in the second direction.

According to this forming system, in a case where the preliminary-formed metal pipe material is transported from the preliminary forming apparatus to the forming apparatus arranged in the second direction, since the gas supply unit is not disposed on the transport path of the metal pipe material, the gas supply unit of the forming apparatus does not obstruct the metal pipe material which is transported from the preliminary forming apparatus to the forming apparatus. In addition, in a case where the formed metal pipe is transported from the forming apparatus to the cutting device arranged in the second direction, since the gas supply unit is not disposed on the transport path of the metal pipe, the gas supply unit of the forming apparatus does not obstruct the metal pipe which is transported from the forming apparatus to the cutting device. Accordingly, it is possible to dispose the gas supply unit so as to be separated from the center of the forming apparatus in the first direction, it is possible to arrange the preliminary forming apparatus, the forming apparatus, and the cutting device in the second direction orthogonal to the first direction, and it is possible to decrease the site area of the forming system.

In addition, a pair of the gas supply units may be provided in the first direction in a state where the center of the forming apparatus is interposed between the gas supply units. In this case, it is possible to dispose the preliminary forming apparatus with respect to the forming apparatus such that the pair of gas supply units do not interfere with the metal pipe material when the metal pipe material is transported from the preliminary forming apparatus to the forming apparatus. In addition, it is possible to dispose the cutting device with respect to the forming apparatus such that the pair of gas supply units do not interfere with the metal pipe when the metal pipe is transported from the forming apparatus to the cutting device.

Moreover, the preliminary forming apparatus, the forming apparatus, and the cutting device are disposed in this order in the second direction. In this case, it is possible to sequentially and continually perform a series of a preliminary forming process, a forming process, and a cutting process on the metal pipe material (metal pipe).

According to the aspect of the present invention, it is possible to provide a forming system in which the gas supply unit of the forming apparatus does not obstruct the metal pipe material which is transported from the preliminary forming apparatus to the forming apparatus and the metal pipe which is transported from the forming apparatus to the cutting device.

Hereinafter, a preferred embodiment of a forming system according to the present invention will be described with reference to the drawings. In addition, in each drawing, the same reference numerals are assigned to the same portions or the corresponding portions, and overlapping descriptions thereof are omitted.

<FIG> is a schematic plan view of a forming system of the present embodiment. As shown in <FIG>, a forming system <NUM> mainly includes a preliminary forming apparatus <NUM> which preliminarily forms a metal pipe material, a forming apparatus <NUM> which forms the preliminary-formed metal pipe material, and a cutting device <NUM> which cuts at least a portion of the formed metal pipe. In addition to the above-described configurations, the forming system <NUM> includes a gas supply source <NUM> which supplies high-pressure gas (gas) to the forming apparatus <NUM>, a wall <NUM> which is provided between the forming apparatus <NUM> and the gas supply source <NUM>, a first handling device <NUM> which transports the preliminary-formed metal pipe material from the preliminary forming apparatus <NUM> to the forming apparatus <NUM>, a second handling device <NUM> which transports the formed metal pipe from the forming apparatus <NUM> to the cutting device <NUM>, and a path <NUM> through which the gas is supplied from the gas supply source <NUM> to the forming apparatus <NUM>.

In the following descriptions, a pipe formed by the forming apparatus <NUM> is referred to as a metal pipe <NUM> (refer to as <FIG>), and a pipe at a step before it is formed by the forming apparatus <NUM> is referred to as metal pipe materials <NUM> to 14B (refer t<FIG>). In addition, a pipe in which both end portions 80c and 80d of the metal pipe <NUM> are cut by the cutting device <NUM> is referred to as a metal pipe <NUM> (refer to <FIG>).

In addition, hereinafter, for explanation, in a plan view as shown in <FIG>, horizontal directions orthogonal to each other with respect to the center of the forming apparatus <NUM> are respectively referred to as a direction X (first direction) and a direction Y (second direction). The preliminary forming apparatus <NUM> and the cutting device <NUM> are disposed one side (hereinafter, simply referred to as one side in the direction X) in the direction X from the forming apparatus <NUM>. Moreover, the preliminary forming apparatus <NUM> is disposed on one side (hereinafter, simply referred to as one side in the direction Y) in the direction Y from the forming apparatus <NUM>, and the cutting device <NUM> is disposed on the other side (hereinafter, simply referred to as the other side in the direction Y) in the direction Y from the forming apparatus <NUM>. That is, the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are disposed in a V shape (or U shape) in a plan view. The preliminary forming apparatus <NUM> and the forming apparatus <NUM> (for example, the center of the preliminary forming apparatus <NUM> and the center of the forming apparatus <NUM>) are connected to each other by a first straight line L1 in a plan view, and the forming apparatus <NUM> and the cutting device <NUM> (for example, the center of the forming apparatus <NUM> and the center of the cutting device <NUM>) are connected to each other by a second straight line L2 in plan view.

The wall <NUM> is provided on the other side (hereinafter, simply referred to as the other side in the direction X) in the direction X from the forming apparatus <NUM>, and the gas supply source <NUM> is provided on the other side in the direction X from the wall <NUM>.

The first handling apparatus <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed between the preliminary forming apparatus <NUM> and the cutting device <NUM>. More specifically, the first handling device <NUM> is disposed on the one side in the direction Y between the preliminary forming apparatus <NUM> and the cutting device <NUM>. The second handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed between the first handling device <NUM> and the cutting device <NUM>. More specifically, the second handling device <NUM> is disposed on the other side in the direction Y between the preliminary forming apparatus <NUM> and the cutting device <NUM>.

The preliminary forming apparatus <NUM> is an apparatus which performs preliminary forming on the transported metal pipe material <NUM> and deforms the metal pipe material <NUM> into a desired shape. Here, the preliminary forming means plastic deformation performing on the metal pipe material <NUM> before the metal pipe <NUM> is formed by the forming apparatus <NUM>. For example, as the preliminary forming, there are various plastic working such as bending or embossing. In the present embodiment, the preliminary forming apparatus <NUM> performs bending (prebending) at a predetermined position of the metal pipe material <NUM>. Accordingly, for example, the preliminary forming apparatus <NUM> includes a component for holding the metal pipe material <NUM>, a component which applies a pressure to the held metal pipe material <NUM> so as to bend the metal pipe material <NUM>, or the like.

The forming apparatus <NUM> is an apparatus which deforms the preliminary-formed metal pipe material 14A (refer to <FIG>) into a desired shape using a blow forming die (die) <NUM> (refer to <FIG>) attached to a main body portion <NUM> so as to obtain the metal pipe <NUM>. The forming apparatus <NUM> includes a pipe holding mechanism <NUM> (refer to <FIG>) which holds the end portion of the metal pipe material 14A, and a pair of gas supply mechanisms (gas supply units) <NUM> and <NUM> which supply gas to the metal pipe material 14A so as to expand the metal pipe material 14A. The pair of gas supply mechanisms <NUM> and <NUM> are disposed in the direction Y in the state where the center of the forming apparatus <NUM> is interposed therebetween. Each of the pair of gas supply mechanisms <NUM> and <NUM> is connected to the gas supply source <NUM> via the path <NUM>. Each of the pair of gas supply mechanisms <NUM> and <NUM> is not disposed on the first straight line L1 and the second straight line L2 shown in <FIG>. Details of the further configurations of the forming apparatus <NUM> and details of the forming method performed by the forming apparatus <NUM> will be described below. However, the center of the main body portion <NUM> in a plan view overlaps the center of the forming apparatus <NUM> in a plan view.

The cutting device <NUM> is a device which cuts at least a portion of the formed metal pipe <NUM> so as to obtain the metal pipe <NUM>. For example, as a method for cutting the metal pipe <NUM> by the cutting device <NUM>, there are various cutting such as laser processing, press processing, or wire cutting processing. In the present embodiment, the cutting device <NUM> radiates end portions 80c and 80d (refer to <FIG>) of the metal pipe <NUM> which are not formed with laser to cut the end portions 80c and 80d. For example, the metal pipe <NUM> which is formed by the laser cutting is subjected to a grinding or the like so as to be shipped as a product.

The gas supply source <NUM> is a device which supplies high-pressure gas to the pair of gas supply mechanisms <NUM> and <NUM> via the path <NUM>. For example, the gas supply source <NUM> includes a compressor and an air tank, and performs the forming of the metal pipe material 14A installed in the forming apparatus <NUM> using the high-pressure gas supplied by the gas supply source <NUM> (the details will be described below). For example, the high-pressure gas uses high-pressure air, high-pressure nitrogen, or the like.

The wall <NUM> is installed between the forming apparatus <NUM> and the gas supply source <NUM> in the direction X, and is a concrete wall which extends in the direction Y. Since the wall <NUM> is disposed on the sides opposite to the preliminary forming apparatus <NUM> and the cutting device <NUM> in the state where the forming apparatus <NUM> is interposed therebetween, it is possible to decrease the distance between the wall <NUM> and the forming apparatus <NUM> in the direction X. For example, the wall <NUM> can be used as a protective wall when the forming apparatus <NUM> or the gas supply source <NUM> is damaged.

The first handling device <NUM> is a device which transports the metal pipe material 14A from the preliminary forming apparatus <NUM> to the forming apparatus <NUM>. For example, as the first handling device <NUM>, a robot arm having multi axes, a transfer feeder, or the like is used. In the present embodiment, from the viewpoint from the metal pipe material 14A being installed at a predetermined position in the forming apparatus <NUM>, a robot arm is used. When the first handling device <NUM> transports the metal pipe material 14A, the first handling device <NUM> is disposed such that the metal pipe material 14A does not come into contact with or does not interfere with one gas supply mechanism <NUM> of the forming apparatus <NUM>.

The second handling device <NUM> is a device which transports the metal pipe <NUM> from the forming apparatus <NUM> to the cutting device <NUM>. For example, as the second handling device <NUM>, a robot arm having multi axes, a transfer feeder, or the like is used. In the present embodiment, from the viewpoint from the metal pipe <NUM> being installed at a predetermined position in the cutting device <NUM>, a robot arm is used. The second handling device <NUM> is disposed such the other gas supply mechanism <NUM> of the forming apparatus <NUM> does not obstruct the transported metal pipe <NUM>.

<FIG> is a schematic configuration view of the forming apparatus and a blow mechanism. As shown in <FIG>, the forming apparatus <NUM> forming the metal pipe <NUM> is configured of a blow forming die <NUM> which includes the upper die <NUM> and the lower die <NUM>, a slider <NUM> which moves at least one of the upper die <NUM> and the lower die <NUM>, a drive section <NUM> which generates a drive force for moving the slider <NUM>, a pipe holding mechanism <NUM> which holds the metal pipe material 14A between the upper die <NUM> and the lower die <NUM>, the pair of gas supply mechanisms <NUM> which supply high-pressure gas (gas) into the metal pipe material 14A which is held by the pipe holding mechanism <NUM>, a heating mechanism (heating unit) <NUM> which supplies power to the metal pipe material 14A held by the pipe holding mechanism <NUM> to heat the metal pipe material 14A, a control unit <NUM> which controls the operations of the drive section <NUM>, the pipe holding mechanism <NUM>, and the blow forming die <NUM>, and the heating mechanism <NUM>, and a water circulation mechanism <NUM> which forcedly cools the blow forming die <NUM> with water. In addition, the pair of gas supply mechanisms <NUM> and <NUM> are connected to a blow mechanism <NUM> which supplies high-pressure gas.

The control unit <NUM> controls a series of controls such as a control for closing the blow forming die <NUM> when the metal pipe material 14A is heated to a quenching temperature (AC3 transformation point temperature or more) or a control for blowing high-pressure gas into the heated metal pipe material 14A. Accordingly, the control unit <NUM> controls the operation of the blow mechanism <NUM> in addition to the operation of the pipe holding mechanism <NUM>, the heating mechanism <NUM>, or the like.

The lower die <NUM> is fixed to a large base <NUM>. The lower die <NUM> is configured of a large steel block, and includes a cavity (recessed portion) <NUM> on the upper surface thereof. In addition, electrode accommodation spaces 11a are provided around the right and left ends (right and left ends in <FIG>) of the lower die <NUM>, and a first electrode <NUM> and a second electrode <NUM> which are configured so as to be movable upward and downward by an actuator (not shown) are provided in the electrode accommodation spaces 11a. Semicircular recessed grooves 17a and 18a corresponding to the lower outer peripheral surface of the metal pipe material 14A are respectively formed on the upper surfaces of the first electrode <NUM> and the second electrode <NUM> (refer to <FIG>), and the metal pipe material 14A can be disposed so as to be exactly fitted to the portions of the recessed grooves 17a and 18a. In addition, a taper recessed surface 17b in which the vicinity is inclined in a taper shape toward the recessed groove 17a so as to be recessed is formed on the front surface (the surface in the outside direction of the die) of the first electrode <NUM>, and a taper recessed surface 18b in which the vicinity is inclined in a taper shape toward the recessed groove 18a so as to be recessed is formed on the front surface of the second electrode <NUM>. In addition, a cooling water passage <NUM> is formed in the lower die <NUM>, and a thermocouple <NUM> which is inserted from the lower portion is provided at the approximately center of the lower die <NUM>. The thermocouple <NUM> is supported to be movable upward and downward by a spring <NUM>.

Moreover, the pair of first electrode <NUM> and second electrode <NUM> positioned on the lower die <NUM> side configure the pipe holding mechanism <NUM>, and can liftably support the metal pipe material 14A between the upper die <NUM> and the lower die <NUM>. In addition, the thermocouple <NUM> only is an example of temperature measurement means, and may be a non-contact type temperature sensor such as a radiation thermometer or an optical thermometer. Moreover, the temperature measurement means may be omitted as long as a relationship between a power-supply time and a temperature can be obtained.

The upper die <NUM> includes a cavity (recessed portion) <NUM> on the lower surface of the upper die and is a steel block in which the cooling water passage <NUM> is built. The upper end portion of the upper die <NUM> is fixed to the slider <NUM>. In addition, the slider <NUM> to which the upper die <NUM> is fixed is suspended by a pressurization cylinder <NUM>, and is guided such that the upper die <NUM> is not laterally swung by guide cylinders <NUM>. The drive section <NUM> according to the present embodiment includes a servo motor <NUM> which generates a drive force for driving the slider <NUM>. The drive section <NUM> is configured of a fluid supply unit which supplies a fluid (a working fluid in a case where a hydraulic cylinder is adopted as the pressurization cylinder <NUM>) driving the pressurization cylinder <NUM> to the pressurization cylinder <NUM>.

As described above, since the blow forming die <NUM> is attached to the main body portion <NUM>, the main body portion <NUM> of the forming apparatus <NUM> includes at least the base <NUM> and the slider <NUM>.

The control unit <NUM> controls the amount of the fluid which is supplied to the pressurization cylinder <NUM> by controlling the servo motor <NUM> of the drive section <NUM>. Accordingly, it is possible to control the movement of the slider <NUM>. In addition, as described above, the drive section <NUM> is not limited to the drive section which applies the drive force to the slider <NUM> via the pressurization cylinder <NUM>. For example, the drive section <NUM> may be mechanically connected to the slider <NUM> and may directly or indirectly apply the drive force generated by the servo motor <NUM> to the slider <NUM>. For example, the drive section <NUM> may adopt a drive mechanism which includes, an eccentric shaft, a drive source (for example, a servo motor, a speed reducer, or the like) which applies a rotating force rotating the eccentric shaft and a conversion unit (for example, a connecting rod, an eccentric sleeve, or the like) which converts a rotation movement of the eccentric shaft into a linear movement so as to move a slider. In addition, in the present embodiment, only the upper die <NUM> moves. However, the lower die <NUM> may move in addition to the upper die <NUM> or instead of the upper die <NUM>. Moreover, in the present embodiment, the drive section <NUM> may not include the servo motor <NUM>.

In addition, similarly to the lower die <NUM>, the first electrode <NUM> and the second electrode <NUM> which are configured so as to be movable upward and downward by an actuator (not shown) are provided in electrode accommodation spaces 12a provided around the right and left ends (right and left ends in <FIG>) of the upper die <NUM>. Semicircular recessed grooves 17a and 18a corresponding to the upper outer peripheral surface of the metal pipe material 14A are respectively formed on the lower surfaces of the first electrode <NUM> and the second electrode <NUM> (refer to <FIG>), and the metal pipe material 14A can be exactly fitted to the recessed grooves 17a and 18a. In addition, the taper recessed surface 17b in which the vicinity is inclined in a taper shape toward the recessed groove 17a so as to be recessed is formed on the front surface (the surface in the outside direction of the die) of the first electrode <NUM>, and the taper recessed surface 18b in which the vicinity is inclined in a taper shape toward the recessed groove 18a so as to be recessed is formed on the front surface of the second electrode <NUM>. Accordingly, the pair of first and second mechanisms <NUM> and <NUM> positioned on the upper die <NUM> side configure the pipe holding mechanism <NUM>, and if the metal pipe material 14A is interposed in the vertical direction by the pair of first and second electrodes <NUM> and <NUM> which are positioned on the upper side and the lower side, the holding mechanism <NUM> is configured so as to surround the metal pipe material 14A to exactly come into close contact with the entire outer circumference of the metal pipe material 14A.

<FIG> show the schematic cross section when the blow forming die <NUM> is viewed from the side surface direction. <FIG> are sectionals view of the blow forming die <NUM> taken along line III-III in <FIG>, and shows a state of the position of the die when blow forming is performed. As shown in <FIG>, the rectangular cavity <NUM> is formed on the upper surface of the lower die <NUM>. The rectangular cavity <NUM> is formed on the lower surface of the upper die <NUM> at the position facing the cavity <NUM> of the lower die <NUM>. In a state where the blow forming die <NUM> is closed, the cavity <NUM> of the lower die <NUM> and the cavity <NUM> of the upper die <NUM> are combined, and a main cavity portion MC which is a rectangular space is formed. As shown in <FIG>, the metal pipe material 14A which is disposed in the main cavity portion MC comes into contact with the inner wall surface of the main cavity portion MC as shown in <FIG> by expansion, and is formed in the shape (here, the cross section is a rectangular shape) of the main cavity portion MC.

As shown in <FIG>, each of the pair of gas supply mechanisms <NUM> includes a cylinder unit <NUM>, a cylinder rod <NUM> which moves backward according to the operation of the cylinder unit <NUM>, and a seal member <NUM> which is connected to the tip on the pipe holding mechanism <NUM> side in the cylinder rod <NUM>. The cylinder unit <NUM> is disposed to be fixed to the base <NUM> via a block <NUM>. A taper surface <NUM> which is tapered is formed on the tip of each seal member <NUM>. One taper surface <NUM> is formed in a shape which can be exactly fitted to abut on the taper recessed surface 17b of the first electrode <NUM>, and the other taper surface <NUM> is formed in a shape which can be exactly fitted to abut on the taper recessed surface 18b of the second electrode <NUM> (refer to <FIG>). A gas passage <NUM> which extends from the cylinder unit <NUM> side toward the tip and through which high-pressure gas supplied from the blow mechanism <NUM> flows is provided in the seal member <NUM>.

The heating mechanism <NUM> includes a power source <NUM>, a lead wire <NUM> which extends from the power source <NUM> and is connected to the first electrode <NUM> and the second electrode <NUM>, and a switch <NUM> which is provided in the intermediate of the lead wire <NUM>. Information is transmitted from (A) to the control unit <NUM>, and the control unit <NUM> acquires temperature information from the thermocouple <NUM> and controls the pressurization cylinder <NUM>, the switch <NUM>, or the like.

The water circulation mechanism <NUM> includes a water tank <NUM> in which water is collected, a water pump <NUM> which pumps and pressurizes the water collected in the water tank <NUM> and feeds the water to the cooling water passage <NUM> of the lower die <NUM> and the cooling water passage <NUM> of the upper die <NUM>, and a pipe <NUM>. Although it is omitted, a cooling tower which decreases the temperature of water or a filter which purifies water may be provided in the pipe <NUM>.

The blow mechanism <NUM> includes a high-pressure gas source <NUM>, an accumulator <NUM> in which the high-pressure gas supplied from the high-pressure gas source <NUM> is accumulated, a first tube <NUM> which extends from the accumulator <NUM> to the cylinder unit <NUM>, a pressure control valve <NUM> and a switching valve <NUM> which are provided in the intermediate of the first tube <NUM>, a second tube <NUM> which extends from the accumulator <NUM> to the gas passage <NUM> formed in the seal member <NUM>, and an on-off valve <NUM> and a check valve <NUM> which are provided in the intermediate of the second tube <NUM>. In addition, the gas supply source <NUM> shown in <FIG> is configured of the high-pressure gas source <NUM> and the accumulator <NUM> in the blow mechanism <NUM>. In addition, the path <NUM> shown in <FIG> is configured of the second tube <NUM>, the on-off valve <NUM>, and the check valve <NUM> in the blow mechanism <NUM>. In the present embodiment, the path <NUM> includes the first tube <NUM>, the pressure control valve <NUM>, and the switching valve <NUM>.

The pressure control valve <NUM> plays a role of supplying high-pressure gas having an operation pressure according to the pushing force required from the seal member <NUM> side to the cylinder unit <NUM>. The check valve <NUM> plays a role of preventing the high-pressure gas in the second tube <NUM> from flowing backward. The switching valve <NUM>, the on-off valve <NUM>, or the like is controlled by the control unit <NUM>.

Next, the operation of the forming system <NUM> will be described. <FIG> shows a pipe loading process in which the metal pipe material 14A which is a material is loaded from a power-supply and heating process in which power is supplied to the metal pipe material 14A so as to heat the metal pipe material 14A. First, the metal pipe material <NUM> (refer to <FIG>) which is a kind of steel to which quenching can be applied is prepared. The metal pipe material <NUM> is held by the preliminary forming apparatus <NUM>, the metal pipe material <NUM> is bent, and the metal pipe material 14A is obtained (refer to <FIG>). As shown in <FIG>, the metal pipe material 14A is disposed on the first and second electrodes <NUM> and <NUM> provided in the lower die <NUM> side by the first handling device <NUM> (refer to <FIG>). Since the recessed grooves 17a and 18a are respectively formed on the first and second electrodes <NUM> and <NUM>, the metal pipe material 14A is positioned by the recessed grooves 17a and 18a. Next, the control unit <NUM> (refer to <FIG>) controls the pipe holding mechanism <NUM> and holds the metal pipe material 14A by the pipe holding mechanism <NUM>. Specifically, as shown in <FIG>, the control unit <NUM> operates an actuator (not shown) which can move the first electrode <NUM> and the second electrode <NUM> forward and backward, and causes the first and second electrodes <NUM> and <NUM> to approach and abut on the first and second electrodes <NUM> and <NUM> positioned vertically. Due to this abutment, both end portions of the metal pipe material 14A are held by the first and second electrodes <NUM> and <NUM> in the vertical direction. In addition, the holding is performed such that the first and second electrodes <NUM> and <NUM> come into close-contact with the entire circumference of the metal pipe material 14A due to the existences of the recessed grooves 17a and 18a which are respectively formed on the first and second electrodes <NUM> and <NUM>. However, the present invention is not limited to the configuration in which the first and second electrodes <NUM> and <NUM> come into close-contact with the entire circumference of the metal pipe material 14A. The first and second electrodes <NUM> and <NUM> may abut on a portion of the metal pipe material 14A in the circumferential direction.

Subsequently, as shown in <FIG>, the control unit <NUM> controls the heating mechanism <NUM> so as to heat the metal pipe material 14A. Specifically, the control unit <NUM> turns on the switch <NUM> of the heating mechanism <NUM>. Accordingly, power is supplied from the power source <NUM> to the metal pipe material 14A, and the metal pipe material 14A itself emits heat (joule heat) due to resistance existing in the metal pipe material 14A. At this time, the measurement value of the thermocouple <NUM> is always observed, and power supply is controlled based on the measured result.

<FIG> shows the blow forming process performed by the forming apparatus and the flow after the blow forming process. As shown in <FIG>, the blow forming die <NUM> is closed to the heated metal pipe material 14A, and the metal pipe material 14A is disposed and sealed in the cavity of the blow forming die <NUM>. Thereafter, both ends of the metal pipe material 14A are sealed by the seal members <NUM> by operating the cylinder units <NUM> of the gas supply mechanisms <NUM> (also referred to as <FIG>). After the sealing is completed, high-pressure gas is blown into the metal pipe material 14A, the metal pipe material 14A which is softened by heating is deformed according to the shape of the cavity, and the metal pipe material 14B is obtained.

The metal pipe material 14A is heated at a high temperature (approximately <NUM>) so as to be softened, and can be blow-formed at a relatively low pressure. Specifically, in a case where a compressed air having a normal temperature (<NUM>) at 4MPa is adopted as the high-pressure gas, the compressed air is heated to approximately <NUM> in the sealed metal pipe material 14A. The compressed air is thermally expanded, and the pressure of the compressed air reaches approximately <NUM> to <NUM> MPa based on a Boyle Charles' law. That is, the metal pipe material 14A of <NUM> is easily expanded by the compressor air which is thermally expanded, and it is possible to obtain the metal pipe <NUM> via the metal pipe material 14B.

The outer peripheral surface of the metal pipe material 14B which is blow-formed and expanded comes into contact with the cavity <NUM> of the lower die <NUM> and is rapidly cooled, and simultaneously, comes into contact with the cavity <NUM> of the upper die <NUM>, is rapidly cooled (since the heat capacities of the upper die <NUM> and the lower die <NUM> are great and the upper die <NUM> and the lower die <NUM> are maintained so as to be low temperatures, if the metal pipe material 14B comes into contact with the upper die <NUM> and the lower die <NUM>, the heat on the surface of the pipe is transmitted to the die side at once) and is subjected to quenching. This cooling method is referred to as die contact cooling or die cooling. Immediately after the metal pipe material 14B is rapidly cooled, austenite is transformed to martensite. Since a cooling speed decreases at the latter half of the cooling, martensite is transformed to another structure (troosite, sorbite, or the like) by radiation heat. Accordingly, it is not necessary to separately perform tempering processing. In addition, in the present embodiment, cooling is performed by supplying a cooling medium to the metal pipe <NUM> instead of the die cooling or in addition to the die cooling.

As described above, the cooling is performed after the blow forming is performed on the metal pipe material 14A, the die is opened, and the metal pipe <NUM> having an approximately rectangular pipe unit 80a and a flat plate-shaped flange section 80b is obtained (refer to <FIG>).

Next, with reference to <FIG>, the aspect of the forming performed by the upper die <NUM> and the lower die <NUM> will be described in detail. In addition, in the descriptions below, the portion corresponding to each of the pipe units 80a of the metal pipe material 14B during the forming and the metal pipe <NUM> before the blow forming die <NUM> is opened is referred to as a "first forming unit 14a", and the portion corresponding to the flange section 80b is referred to as a "second forming unit 14b".

As shown in <FIG>, in the forming apparatus <NUM> according to the present embodiment, the blow forming is not performed in the state where the upper die <NUM> and the lower die <NUM> are completely closed (clamped). That is, since a constant separation state is maintained, the blowing forming is performed in a state where sub cavity portions SC1 and SC2 are formed beside the main cavity portion MC. In this state, the main cavity portion MC is formed between the surface on a reference line LV1 of the cavity <NUM> and the surface on the reference line LV2 of the cavity <NUM>. In addition, a sub cavity portion SC1 is formed between the surface of a first protrusion 12b outside the main cavity portion MC in the upper die <NUM> and the surface of a first protrusion 11b outside the main cavity portion MC in the lower die <NUM>. Similarly, a sub cavity portion SC2 is formed between the surface of a second protrusion 12c outside the main cavity portion MC in the upper die <NUM> and the surface of a second protrusion 11c outside the main cavity portion MC in the lower die <NUM>. The main cavity portion MC and the sub cavity portions SC1 and SC2 communicate with each other. In addition, in the present embodiment, the surface of the first protrusion 12b of the upper die <NUM> configuring the sub cavity portion SC1 and the surface of the first protrusion 11b of the lower die <NUM> extend to the end portions (the right sides in a paper surface in each of <FIG>) of the upper die <NUM> and the lower die <NUM> in the width direction in a state of being separated from each other in the vertical direction. Similarly, the surface of the second protrusion 12c of the upper die <NUM> configuring the sub cavity portion SC2 and the surface of the second protrusion 11c of the lower die <NUM> extend to the end portions (the left sides in a paper surface in each of <FIG>) of the upper die <NUM> and the lower die <NUM> in the width direction in a state of being separated from each other in the vertical direction. Accordingly, the sub cavities SC1 and SC2 communicate with the outside of the die. As a result, as shown in <FIG>, the metal pipe material 14B which is softened by heating and into which high-pressure gas is injected enter not only the main cavity portion MC but also the sub cavity portions SC1 and SC2, and is expanded.

In the example shown in <FIG>, since the main cavity portion MC is configured to have a rectangular cross section, the metal pipe material 14A is blow-formed according to the shape and is formed in a tubular shape having a rectangular cross section. In addition, the portion corresponds to the first forming unit 14a which becomes a pipe unit 80a. However, the shape of the main cavity portion MC is not particularly limited. All sectional shapes such as a circular cross section, an elliptical cross section, or a polygonal cross section may be adopted according to a desired shape. In addition, since the main cavity portion MC and the sub cavity portions SC1 and SC2 communicate with each other, a portion of the metal pipe material 14B enters the sub cavity portions SC1 and SC2. The portion corresponds to the second forming unit 14b which becomes the flange section 80b by crushing.

As shown in <FIG>, at the step after the blow forming or the step during the blow forming, the upper die <NUM> and the lower die <NUM> separated from each other approach each other. According to this operation, volumes of the sub cavity portions SC1 and SC2 decrease, the internal space of the second forming unit 14b decreases, and the second forming unit 14b is folded. That is, according to approaching between the upper die <NUM> and the lower die <NUM>, the forming unit 14b of the metal pipe material 14B entering the sub cavity portions SC1 and SC2 is pressed and crushed. As a result, the second forming unit 14b which is crushed in the longitudinal direction of the metal pipe material 14B is formed on the outer peripheral surface of the metal pipe material 14B. In addition, the time until the press forming of the flange section 80b is completed from the blow forming is dependent on the kind of the metal pipe material <NUM>. However, the press forming of the flange section 80b is completed at approximately <NUM> to <NUM> seconds.

In the example shown in <FIG>, a gap corresponding to the thickness of the crushed second forming unit 14b (that is, flange section 80b) is formed between the surface of the first protrusion 12b of the upper die <NUM> and the surface of the first protrusion 11b of the lower die <NUM> configuring the sub cavity portion SC1. Similarly, a gap corresponding to the thickness of the crushed second forming unit 14b (that is, flange section 80b) is formed between the surface of the second protrusion 12c of the upper die <NUM> and the surface of the second protrusion 11c of the lower die <NUM> configuring the sub cavity portion SC2. Even in this state, the sub cavity portions SC1 and SC2 communicate with the outside of the die. That is, in the example shown in <FIG>, when the flange section 80b (second forming unit 14b of the metal pipe material 14B) of the metal pipe <NUM> is formed, the sub cavity portions SC1 and SC2 communicate with the outside of the die from forming starting to forming completion. Accordingly, since air in the sub cavity portions SC1 and SC2 can be extracted to the outside of the die from the forming starting to the forming completion, it is possible to improve quality of a forming product.

Moreover, since the upper die <NUM> and the lower die <NUM> approach each other after the blow forming, not only the second forming unit 14b of the metal pipe material 14B entering the sub cavity portions SC1 and SC2 but also the first forming unit 14a of the metal pipe material 14B of the main cavity portion MC are crushed. Since the metal pipe material 14B is heated and softened, by adjusting a closing speed of the die or the pressurized gas, it is possible to finish the metal pipe <NUM> without loosening or distortion.

In addition, in the obtained metal pipe <NUM>, the metal pipe <NUM> is transferred from the forming apparatus <NUM> to the cutting device <NUM> using the second handling device <NUM>. Both end portions 80c and 80d of the metal pipe <NUM> which are not expanded are cut by the cutting device <NUM>, and the metal pipe <NUM> which is a forming product is obtained (refer to <FIG>).

In this way, according to the forming system <NUM> which performs a series of processing, both of the pair of gas supply mechanisms <NUM> and <NUM> are provided so as not to be disposed on the first straight line L1 which connects the preliminary forming apparatus <NUM> and the main body portion <NUM> of the forming apparatus <NUM> to each other in a plan view and the second straight line L2 which connects the cutting device <NUM> and the main body portion <NUM> to each other in a plan view. Accordingly, in the case where the preliminary-formed metal pipe material 14A is transported from the preliminary forming apparatus <NUM> to the main body portion <NUM>, the gas supply mechanisms <NUM> and <NUM> are not disposed on the first straight line L1 which is a portion of the transport path of the metal pipe material 14A. Accordingly, the supply mechanisms <NUM> and <NUM> of the forming apparatus <NUM> do not obstruct the metal pipe material 14A which is transported from the preliminary forming apparatus <NUM> to the forming apparatus <NUM>. In addition, in the case where the formed metal pipe <NUM> is transported from the forming apparatus <NUM> to the cutting device <NUM>, the gas supply mechanisms <NUM> and <NUM> are not disposed on the second straight line L2 which is a portion of the transport path of the metal pipe <NUM>. Accordingly, the supply mechanisms <NUM> and <NUM> of the forming apparatus <NUM> do not obstruct the metal pipe <NUM> which is transported from the forming apparatus <NUM> to the cutting device <NUM>. Therefore, according to the forming system <NUM>, since it is not necessary to increase the size of the cylinder unit <NUM> which is the moving mechanism for moving the gas supply mechanisms <NUM> and <NUM> or the like and it is not necessary to largely move the cylinder rods <NUM> of the gas supply mechanisms <NUM> and <NUM> or the like, the gas supply mechanisms <NUM> and <NUM> of the forming apparatus <NUM> do not obstruct the metal pipe material 14A which is transported from the preliminary forming apparatus <NUM> to the forming apparatus <NUM> and the metal pipe <NUM> which is transported from the forming apparatus <NUM> to the cutting device <NUM>.

In addition, the preliminary forming apparatus <NUM> and the cutting device <NUM> are disposed on the one side in the direction X from the forming apparatus <NUM>, the preliminary forming apparatus <NUM> is disposed on the one side in the direction Y from the forming apparatus <NUM>, and the cutting device <NUM> is disposed on the other side in the direction Y from the forming apparatus <NUM>. In this case, the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are not disposed in a row in the horizontal direction, and is disposed in a V shape, a U shape, or the like in a plan view. As a specific example, in a case where the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are simply disposed in a row, the maximum length in the longitudinal direction (direction Y) of the region occupied by the forming system in a plan view is approximately <NUM>, the maximum length in a transverse direction (direction X) of the region is approximately <NUM>, and an area which is obtained by multiplying the lengths is approximately <NUM><NUM>. Meanwhile, the maximum length in the longitudinal direction of the region occupied by the forming system <NUM> according to the present invention in a plan view is approximately <NUM>, the maximum length in the transverse direction of the region is approximately <NUM>, and the area is approximately <NUM><NUM>. That is, compared to the case where the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are simply disposed in a row, it is possible to decrease the site area of the forming system <NUM> in the present embodiment.

In addition, the pair of gas supply mechanisms <NUM> and <NUM> are provided in the direction Y in a state where the center of the forming apparatus <NUM> is interposed therebetween. Accordingly, when the metal pipe material 14A is transported from the preliminary forming apparatus <NUM> to the forming apparatus <NUM>, it is possible to dispose the preliminary forming apparatus <NUM> with respect to the forming apparatus <NUM> such that the pair of gas supply mechanisms <NUM> and <NUM> do not interfere with the metal pipe material 14A.

Moreover, the forming system <NUM> includes the first handling device <NUM> which transports the metal pipe material 14A from the preliminary forming apparatus <NUM> to the forming apparatus <NUM>, the first handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed between the preliminary forming apparatus <NUM> and the cutting device <NUM>. Accordingly, it is possible to dispose the first handling device <NUM> transporting the metal pipe material 14A such that the transported metal pipe material 14A does not interfere with one gas supply mechanism <NUM> of the forming apparatus <NUM>. Similarly, the forming system <NUM> includes the second handling device <NUM> which transports the metal pipe <NUM> from the forming apparatus <NUM> to the cutting device <NUM>, the second handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed between the first handling device <NUM> and the cutting device <NUM>. Accordingly, it is possible to dispose the second handling device <NUM> such that the second handling device <NUM> does not obstruct the metal pipe <NUM> transported by the other gas supply mechanism <NUM> of the forming apparatus <NUM>.

Moreover, the forming system <NUM> includes the wall <NUM> which is provided on the other side in the direction X from the forming apparatus <NUM>, and the gas supply source <NUM> which is disposed on the other side in the direction X from the wall <NUM> and supplies gas to the gas supply mechanism <NUM>. Accordingly, the wall <NUM> can be disposed on the sides opposite to the preliminary forming apparatus <NUM> and the cutting device <NUM> in the state where the forming apparatus <NUM> is interposed therebetween, and it is possible to decrease the distance between the wall <NUM> and the forming apparatus <NUM> in the direction X. Accordingly, it is possible to further decrease the site area of the forming system <NUM>.

<FIG> is a schematic plan view of the forming system according to another embodiment of the present invention. As shown in <FIG>, compared to the forming system <NUM> shown in <FIG> and a forming system 1A according to another embodiment, the positional relationships among the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, the cutting device <NUM>, the first handling device <NUM>, the second handling device <NUM>, and the path <NUM> are different from each other.

The preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are disposed in this order in the direction Y. That is, the forming apparatus <NUM> is interposed between the preliminary forming apparatus <NUM> and the cutting device <NUM> in the direction Y. More specifically, the preliminary forming apparatus <NUM> is disposed on one side in the direction Y from the forming apparatus <NUM>, and the cutting device <NUM> is disposed on the other side in the direction Y from the forming apparatus <NUM>. Accordingly, the region between the preliminary forming apparatus <NUM> and the forming apparatus <NUM> becomes a linear transport path of the metal pipe material 14A which extends in the direction Y, and the region between the forming apparatus <NUM> and the cutting device <NUM> becomes a linear transport path of the metal pipe <NUM> which extends in the direction Y. Here, the first straight line L1 which connects the preliminary forming apparatus <NUM> and the forming apparatus <NUM> to each other and the second straight line L2 which connects the forming apparatus <NUM> and the cutting device <NUM> to each other are the same as each other in the direction Y. That is, the first straight line L1 becomes the transport path of the metal pipe material 14A and the second straight line L2 becomes the transport path of the metal pipe <NUM>.

The first handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed between the preliminary forming apparatus <NUM> and the forming apparatus <NUM>. More specifically, the first handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed on the one side in the direction Y from the forming apparatus <NUM>. The second handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed between the forming apparatus <NUM> and the cutting device <NUM>. More specifically, the second handling device <NUM> is disposed on the one side in the direction X from the forming apparatus <NUM> and is disposed on the other side in the direction Y from the forming apparatus <NUM>.

The pair of gas supply mechanisms <NUM> and <NUM> including the forming apparatus <NUM> are disposed in the direction X in the state where the center of the forming apparatus <NUM> is interposed therebetween. The pair of gas supply mechanisms <NUM> and <NUM> are not disposed in the region between the preliminary forming apparatus <NUM> and the forming apparatus <NUM> which is the transport path of the metal pipe material 14A, and in the region between the forming apparatus <NUM> and the cutting device <NUM> which is the transport path of the metal pipe <NUM>. That is, each of the pair of gas supply mechanisms <NUM> and <NUM> is not disposed on the first straight line L1 and the second straight line L2.

According to the forming system 1A of another embodiment, the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are disposed in this order in the direction Y, and the pair of gas supply mechanisms <NUM> and <NUM> including the forming apparatus <NUM> are disposed in the direction X orthogonal to the direction Y in the state where the center of the forming apparatus <NUM> is interposed therebetween. Accordingly, since the pair of gas supply mechanisms <NUM> and <NUM> are not disposed on the transport path of the metal pipe material 14A and the pair of gas supply mechanisms <NUM> and <NUM> are not disposed on the transport path of the metal pipe <NUM>, the pair of gas supply mechanisms <NUM> and <NUM> do not obstruct the metal pipe <NUM> which is transported from the forming apparatus <NUM> to the cutting device <NUM>. In addition, the pair of gas supply mechanisms <NUM> and <NUM> can be arranged n the direction X, the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> can be arranged in the direction Y, and it is possible to decrease the site area of the forming system 1A.

Moreover, since the preliminary forming apparatus <NUM>, the forming apparatus <NUM>, and the cutting device <NUM> are disposed in this order in the direction Y, a series of preliminary forming processing, forming processing, and cutting process can be sequentially and continuously performed on the metal pipe material 14A (metal pipe <NUM>).

Hereinbefore, preferred embodiments of the present invention are described. However, the present invention is not limited to the above-described embodiments. For example, in the embodiments, the forming apparatus <NUM> may not necessarily have the heating mechanism <NUM>. The metal pipe material 14A may be heated before it is installed in the forming apparatus <NUM>. In this case, the pipe holding mechanism <NUM> may not be configured of the first electrode <NUM> and the second electrode <NUM>.

In addition, in the above-described embodiments, both of the pair of gas supply mechanisms <NUM> and <NUM> may not be connected to the gas supply source <NUM>, and one of the pair of gas supply mechanisms <NUM> and <NUM> may be connected to the gas supply source <NUM>. In this case, any one of the pair of gas supply mechanisms <NUM> and <NUM> may be configured so as to discharge high-pressure gas.

In addition, in the embodiment, the pair of gas supply mechanisms <NUM> and <NUM> are provided in the direction Y in the state where the center of the forming apparatus <NUM> is interposed therebetween. In another embodiment, the pair of gas supply mechanisms <NUM> and <NUM> are provided in the direction X in the state where the center of the forming apparatus <NUM> is interposed therebetween. However, the pair of the gas supply mechanisms <NUM> and <NUM> can be one gas supply mechanism. That is, the gas supply mechanism <NUM> is separated from the center of the forming apparatus <NUM> and is provided in the direction X or the direction Y.

In addition, in the embodiments, the flange sections are provided on the metal pipes <NUM> and <NUM>. However, the forming systems <NUM> and 1A can be applied to the case where a metal pipe in which the flange sections are not provided is formed.

Claim 1:
A forming system (<NUM>) which expands and forms a metal pipe (<NUM>, 14A, <NUM>) in a die (<NUM>), comprising:
a preliminary forming apparatus (<NUM>) which preliminarily forms a metal pipe material (<NUM>, 14A);
a heating mechanism (<NUM>) for heating the metal pipe material (<NUM>, 14A);
a forming apparatus (<NUM>) which includes a gas supply unit (<NUM>) which supplies gas into the preliminary-formed and heated metal pipe material (<NUM>, 14A) to expand the metal pipe material (<NUM>, 14A) and a main body portion (<NUM>) to which the die (<NUM>) is attached; and
a cutting device (<NUM>) which cuts at least a portion of the formed metal pipe (<NUM>),
wherein the gas supply unit (<NUM>) is provided so as not to be disposed on a first straight line (L1) which connects the preliminary forming apparatus (<NUM>) and the main body portion (<NUM>) in a plan view and a second straight line (L2) which connects the cutting device (<NUM>) and the main body portion (<NUM>) in a plan view;
wherein in a case where horizontal directions orthogonal to each other with respect to a center of the forming apparatus (<NUM>) are a first direction (X) and a second direction (Y), the preliminary forming apparatus (<NUM>) and the cutting device (<NUM>) are disposed on one side in the first direction (X) from the forming apparatus (<NUM>),
wherein the preliminary forming apparatus (<NUM>) is disposed on one side in the second direction (Y) from the forming apparatus (<NUM>), and
wherein the cutting device (<NUM>) is disposed on the other side in the second direction (Y) from the forming apparatus (<NUM>) .