Patent Description:
In the related art, a forming apparatus for forming a metal pipe including a pipe portion and a flange portion by supplying a gas into a heated metal pipe material and expanding the material is known. For example, the following PTL <NUM> discloses a forming apparatus including: upper and lower dies to be paired with each other; a gas supply portion that supplies a high-pressure gas into a metal pipe material held between the upper and lower dies; a heating mechanism that heats the metal pipe material; and a cavity portion formed by combining the upper and lower dies. PTL <NUM> discloses a molding apparatus which can reuse a gas after expansion molding in a suitable manner. PTL <NUM> discloses a molding apparatus which inhibits excessive increase of a pressure of a gas in a metal pipe material.

In order to improve the productivity of the metal pipe formed by the forming apparatus as shown in PTL <NUM>, it is necessary to rapidly discharge the high-pressure gas from the metal pipe. In this case, the discharge noise of the gas becomes loud, and thus, the discharge noise can be noise to the worker of the forming apparatus or the like. Therefore, countermeasures against the above-described discharge noise are required.

An object of the present disclosure is to provide a forming system capable of taking countermeasures against discharge noise.

According to an aspect of the present disclosure, there is provided a forming system for forming a metal pipe having a hollow shape, the system including: a forming apparatus including a gas supply portion that supplies gas into a heated metal pipe material when forming the metal pipe, and a discharge unit that discharges the gas which is in the formed metal pipe; a floor surface on which the forming apparatus is placed; and an underground pit provided at a lower portion of the floor surface, in which an exhaust port of the discharge unit is positioned in an internal space of a structure having the internal space, and the discharge unit includes an exhaust pipe positioned in the underground pit as the structure and provided with the exhaust port.

According to the forming system, the exhaust port of the discharge unit is positioned in the internal space of the structure having the internal space. Therefore, the discharge noise generated when the high-pressure gas is exhausted from the exhaust port is generated in the structure. In this case, the structure functions as a silencer for the discharge noise. Therefore, the discharge noise is less likely to be noisy to a worker and the like who works around the forming apparatus. Therefore, by using the above-described forming system, it is possible to take countermeasures against the discharge noise.

The forming system includes: a floor surface on which the forming apparatus is placed; and an underground pit provided at a lower portion of the floor surface. The discharge unit may include an exhaust pipe positioned in the underground pit as the structure and provided with the exhaust port.

According to this forming system, the exhaust pipe included in the discharge unit and provided with the exhaust port is positioned in the underground pit provided at the lower portion of the floor surface. Accordingly, the discharge noise generated when the high-pressure gas is exhausted from the exhaust port is generated in the underground pit. Therefore, the discharge noise is less likely to be noisy to the worker and the like who is on the floor surface and works around the forming apparatus. Therefore, by using the above-described forming system, it is possible to take countermeasures against the discharge noise. The structure that functions as a silencer is provided in the underground pit, which contributes to reducing the space of the entire forming apparatus.

The forming apparatus may further include an electrode for heating the metal pipe material and a power supply line connected to the electrode, the power supply line may have a conductor accommodated in the underground pit, and in the underground pit, the exhaust port may face the conductor. In this case, the conductor heated by energizing the electrodes can be cooled by the gas exhausted from the exhaust port.

According to an aspect of the present disclosure, it is possible to provide a forming system capable of taking countermeasures against discharge noise.

Hereinafter, preferred embodiments of a forming system according to an aspect of the present disclosure 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 repeated descriptions thereof are omitted.

<FIG> is a schematic configuration view of a forming apparatus of a forming system according to the present embodiment. As shown in <FIG>, a forming apparatus <NUM> for forming a metal pipe includes a forming die <NUM> including an upper die <NUM> and a lower die <NUM>, a drive mechanism <NUM> which moves at least one of the upper die <NUM> and the lower die <NUM>, a pipe holding mechanism <NUM> which holds a metal pipe material <NUM> disposed between the upper die <NUM> and the lower die <NUM>, a heating mechanism <NUM> which energizes the metal pipe material <NUM> held by the pipe holding mechanism <NUM> to heat the metal pipe material <NUM>, a gas supply portion <NUM> which supplies a high-pressure gas (gas) into the metal pipe material <NUM> which is held between the upper die <NUM> and the lower die <NUM> and is heated, a pair of gas supply mechanisms <NUM> and <NUM> for supplying the gas from the gas supply portion <NUM> into the metal pipe material <NUM> held by the pipe holding mechanism <NUM>, and a water circulation mechanism <NUM> which forcibly water-cools the forming die <NUM>, and a controller <NUM> which controls driving of the drive mechanism <NUM>, driving of the pipe holding mechanism <NUM>, driving of the heating mechanism <NUM>, and gas supply of the gas supply portion <NUM>. In the following, the metal pipe material <NUM> is a hollow structure body before forming, and the metal pipe is a hollow structure after forming. Therefore, each of the metal pipe materials <NUM> and the metal pipe has a hollow shape.

The lower die <NUM>, which is one part of the forming die <NUM>, is fixed to a base stage <NUM>. The lower die <NUM> is configured with a large steel block and includes a rectangular cavity (recessed portion) <NUM> on the upper surface of the lower die <NUM>, for example. A cooling water passage <NUM> is formed in the lower die <NUM>. Further, the lower die <NUM> includes a thermocouple <NUM> inserted from below substantially at the center. The thermocouple <NUM> is supported to be movable upward or downward by a spring <NUM>.

Furthermore, the spaces 11a are provided in the vicinity of left and right ends (left and right ends in <FIG>) of the lower die <NUM>, and in the spaces 11a, the electrodes <NUM> and <NUM> (lower electrodes or like), which are movable portions of the pipe holding mechanism <NUM> and will be described later, are disposed to be capable of advancing and retreating upward and downward. In addition, the metal pipe material <NUM> is placed on the lower electrodes <NUM> and <NUM>, and accordingly, the lower electrodes <NUM> and <NUM> come into contact with the metal pipe material <NUM> disposed between the upper die <NUM> and the lower die <NUM>. Accordingly, the lower electrodes <NUM> and <NUM> are electrically connected to the metal pipe material <NUM>.

Insulating materials <NUM> for preventing energization are respectively provided between the lower die <NUM> and the lower electrode <NUM> and under the lower electrode <NUM>, and between the lower die <NUM> and the lower electrode <NUM> and under the lower electrode <NUM>. Each of the insulating materials <NUM> is fixed to an advancing and retreating rod <NUM>, which is a movable portion of an actuator (not shown) that configures the pipe holding mechanism <NUM>. The actuator is for moving the lower electrodes <NUM> and <NUM> or the like upward or downward and a fixation portion of the actuator is held on the base stage <NUM> side together with the lower die <NUM>.

The upper die <NUM>, which is the other part of the forming die <NUM>, is fixed to a slide <NUM> (which will be described later) that configures the drive mechanism <NUM>. The upper die <NUM> is configured with a large steel block, a cooling water passage <NUM> is formed in the upper die <NUM>, and the upper die <NUM> includes a rectangular cavity (recessed portion) <NUM> on the lower surface of the upper die <NUM>, for example. The cavity <NUM> is provided at a position facing the cavity <NUM> of the lower die <NUM>.

Similar to the lower die <NUM>, spaces 12a are provided in the vicinity of left and right ends (left and right ends in <FIG>) of the upper die <NUM>, and electrodes <NUM> and <NUM> (upper electrodes) or the like, which are movable portions of the pipe holding mechanism <NUM> and will be described later, are disposed in the spaces 12a to be capable of advancing and retreating upward and downward. In addition, in a state where the metal pipe material <NUM> is placed on the lower electrodes <NUM> and <NUM>, the upper electrodes <NUM> and <NUM> move downward, and accordingly, the upper electrodes <NUM> and <NUM> come into contact with the metal pipe material <NUM> disposed between the upper die <NUM> and the lower die <NUM>. Accordingly, the upper electrodes <NUM> and <NUM> are electrically connected to the metal pipe material <NUM>.

Insulating materials <NUM> for preventing energization are respectively provided between the upper die <NUM> and the upper electrode <NUM> and above the upper electrode <NUM>, and between the upper die <NUM> and the upper electrode <NUM> and above the upper electrode <NUM>. Each of the insulating materials <NUM> is fixed to an advancing and retreating rod <NUM>, which is a movable portion of an actuator (not shown) that configures the pipe holding mechanism <NUM>. The actuator is for moving the upper electrodes <NUM> and <NUM> or the like upward or downward and a fixation portion of the actuator is held on the slide <NUM> side of the drive mechanism <NUM> together with the upper die <NUM>.

At the right part of the pipe holding mechanism <NUM>, a semi-arc-shaped concave groove 18a corresponding to an outer peripheral surface of the metal pipe material <NUM> is formed on each of surfaces of the electrodes <NUM> and <NUM> that face each other (refer to <FIG>). At the portion of the concave groove 18a, the metal pipe material <NUM> can be placed to be fitted thereinto. At the right part of the pipe holding mechanism <NUM>, on the exposed surfaces of the insulating materials <NUM> and <NUM> that face each other, similar to the concave groove 18a, a semi-arc-shaped concave groove corresponding to the outer peripheral surface of the metal pipe material <NUM> is formed. In addition, on the front surface (surface facing the outside of the die) of the electrode <NUM>, the tapered concave surface 18b which is recessed with peripheries thereof inclined to form a tapered shape toward the concave groove 18a, is formed. Accordingly, when the metal pipe material <NUM> is sandwiched in the up-down direction at the right part of the pipe holding mechanism <NUM>, the electrodes <NUM> can exactly surround the outer periphery of a right end portion of the metal pipe material <NUM> so as to come into close contact with the entire periphery.

At the left part of the pipe holding mechanism <NUM>, a semi-arc-shaped concave groove 17a corresponding to an outer peripheral surface of the metal pipe material <NUM> is formed on each of surfaces of the electrodes <NUM> and <NUM> that face each other (refer to <FIG>). At the portion of the concave groove 17a, the metal pipe material <NUM> can be placed to be fitted thereinto. At the left part of the pipe holding mechanism <NUM>, on the exposed surfaces of the insulating materials <NUM> and <NUM> that face each other, similar to the concave groove 18a, a semi-arc-shaped concave groove corresponding to the outer peripheral surface of the metal pipe material <NUM> is formed. In addition, on the front surface (surface facing the outside of the die) of the electrode <NUM>, the tapered concave surface 17b which is recessed with peripheries thereof inclined to form a tapered shape toward the concave groove 17a, is formed. Accordingly, when the metal pipe material <NUM> is sandwiched in the up-down direction at the left part of the pipe holding mechanism <NUM>, the electrodes <NUM> can exactly surround the outer periphery of a left end portion of the metal pipe material <NUM> so as to come into close contact with the entire periphery.

Returning to <FIG>, the drive mechanism <NUM> includes the slide <NUM> which moves the upper die <NUM> such that the upper die <NUM> and the lower die <NUM> are combined to each other, a shaft <NUM> which generates a driving force for moving the slide <NUM>, and a connecting rod <NUM> for transmitting the driving force generated by the shaft <NUM> to the slide <NUM>. The shaft <NUM> extends in the left-right direction above the slide <NUM>, is supported to be rotatable, and includes an eccentric crank 82a which protrudes from left and right ends at a position separated from the axial center of the shaft <NUM> and extends in the left-right direction. The eccentric crank 82a and a rotary shaft 81a which is provided above the slide <NUM> and extends in the left-right direction are connected to each other by the connecting rod <NUM>. In a case of the drive mechanism <NUM>, the upward and downward movement of the slide <NUM> can be controlled by the controller <NUM> that controls rotation of the shaft <NUM> such that the height of the eccentric crank 82a in the up-down direction is changed and the positional change of the eccentric crank 82a is transmitted to the slide <NUM> through the connecting rod <NUM>. Here, oscillation (rotary motion) of the connecting rod <NUM> generated when the positional change of the eccentric crank 82a is transmitted to the slide <NUM> is absorbed by the rotary shaft 81a. Note that, the shaft <NUM> is rotated or stopped in accordance with the driving of a motor or the like controlled by the controller <NUM>, for example.

The heating mechanism <NUM> includes a power supply portion <NUM> and a power supply line <NUM> which electrically connects the power supply portion <NUM> and the electrodes <NUM> and <NUM> to each other. The power supply portion <NUM> includes a DC power source and a switch and can energize the metal pipe material <NUM> through the power supply line <NUM> and the electrodes <NUM> and <NUM> in a state where the electrodes <NUM> and <NUM> are electrically connected to the metal pipe material <NUM>. The power supply line <NUM> has a power supply line 52A connected to the lower electrode <NUM> and a power supply line 52B connected to the lower electrode <NUM>.

In the heating mechanism <NUM>, a DC current output from the power supply portion <NUM> is transmitted through the power supply line 52A and input to the electrode <NUM>. Then, the DC current passes through the metal pipe material <NUM> and is input to the electrode <NUM>. Then, the DC current is transmitted through the power supply line 52B and input to the power supply portion <NUM>.

Returning to <FIG>, each of the pair of gas supply mechanisms <NUM> includes a cylinder unit <NUM>, a cylinder rod <NUM> that advances and retreats in accordance with the operation of the cylinder unit <NUM>, and a seal member <NUM> connected to the tip of the cylinder rod <NUM> on the pipe holding mechanism <NUM> side. The cylinder unit <NUM> is placed and fixed on a block <NUM>. At the tip of the seal member <NUM>, the tapered surface <NUM> is formed to be tapered, and the tip is configured to have a shape in accordance with the tapered concave surfaces 17b and 18b of the electrodes <NUM> and <NUM> (refer to <FIG>). The seal member <NUM> is provided with a gas passage <NUM> which extends toward the tip from the cylinder unit <NUM> side and in which a high-pressure gas supplied from the gas supply portion <NUM> flows.

The gas supply portion <NUM> includes a gas source <NUM>, an accumulator <NUM> in which the gas supplied by the gas source <NUM> is collected, a first tube <NUM> which extends from the accumulator <NUM> to the cylinder unit <NUM> of the gas supply mechanism <NUM>, a pressure control valve <NUM> and a switching valve <NUM> which are interposed in 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 a pressure control valve <NUM> and a check valve <NUM> which are interposed in the second tube <NUM>. The pressure control valve <NUM> plays a role of supplying a gas, which has an operation pressure applied to a pressing force against the metal pipe material <NUM> of the seal member <NUM>, to the cylinder unit <NUM>. The check valve <NUM> plays a role of preventing the high-pressure gas from backflowing in the second tube <NUM>. The pressure control valve <NUM> interposed in the second tube <NUM> plays a role of supplying a gas having an operation pressure for expanding the metal pipe material <NUM> to the gas passage <NUM> of the seal member <NUM> by being controlled by the controller <NUM>. The second tube <NUM> is branched from the check valve <NUM> into two, and has a gas supply line L1 that extends to one of the gas supply mechanisms <NUM> and a gas supply line L2 that extends to the other one of the gas supply mechanisms <NUM>.

The forming apparatus <NUM> includes exhaust mechanisms (discharge units) 200A and 200B for exhausting the gas in the formed metal pipe. The exhaust mechanism 200A is connected to the gas supply line L1, and the exhaust mechanism 200B is connected to the gas supply line L2. Therefore, the exhaust mechanism 200A exhausts the gas in the metal pipe through the gas supply line L1 and the gas passage <NUM> of one of the gas supply mechanisms <NUM>. The exhaust mechanism 200B exhausts the gas in the metal pipe through the gas supply line L2 and the gas passage <NUM> of the other one of the gas supply mechanisms <NUM>. Each of the exhaust mechanisms 200A and 200B has, for example, an exhaust pipe (details thereof will be described later) that branches from each supply line and is provided with an exhaust port. Each of the exhaust mechanisms 200A and 200B has a pressure control valve, a safety valve, and the like of which opening and closing are controlled by the controller <NUM>. The position where the pressure control valve, the safety valve, and the like are provided is not particularly limited.

The controller <NUM> can control the pressure control valve <NUM> of the gas supply portion <NUM> such that a gas having a desired operation pressure is supplied into the metal pipe material <NUM>. With the information transmitted from (A) shown in <FIG>, the controller <NUM> acquires temperature information from the thermocouple <NUM> and controls the drive mechanism <NUM> and the power supply portion <NUM>.

The water circulation mechanism <NUM> includes a water tank <NUM> which collects water, a water pump <NUM> which pumps up the water collected in the water tank <NUM> and pressurizes and sends 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 omitted, a cooling tower for lowering the water temperature and a filter for purifying the water may be interposed in the pipe <NUM>.

Next, a metal pipe forming method using the forming apparatus <NUM> will be described. First, the quenchable steel type cylindrical metal pipe material <NUM> is prepared. For example, the metal pipe material <NUM> is placed (loaded) on the electrodes <NUM> and <NUM> provided on the lower die <NUM> side by using a robot arm or the like. Since the concave grooves 17a and 18a are formed on the electrodes <NUM> and <NUM>, the metal pipe material <NUM> is positioned by the concave grooves 17a and 18a.

Next, the controller <NUM> controls the drive mechanism <NUM> and the pipe holding mechanism <NUM> such that the metal pipe material <NUM> is held by the pipe holding mechanism <NUM>. Specifically, the drive mechanism <NUM> is driven such that the upper die <NUM> held on the slide <NUM> side and the upper electrodes <NUM> and <NUM> are moved to the lower die <NUM> side, the actuator that can make the upper electrodes <NUM> and <NUM> and the lower electrodes <NUM> and <NUM> included in the pipe holding mechanism <NUM> advance and retreat is operated, and accordingly, the vicinity of the both end portions of the metal pipe material <NUM> is sandwiched by the pipe holding mechanism <NUM> from above and below. The sandwiching is performed in an aspect in which the concave grooves 17a and 18a formed on the electrodes <NUM> and <NUM> and the concave grooves formed on the insulating materials <NUM> and <NUM> are provided such that the electrodes <NUM> and <NUM> come into close contact with the vicinity of the both end portions of the metal pipe material <NUM> over the entire periphery.

At this time, as shown in <FIG>, the end portion of the metal pipe material <NUM> on the electrode <NUM> side protrudes toward the seal member <NUM> beyond a boundary between the concave grooves 18a and the tapered concave surfaces 18b of the electrodes <NUM> in the extending direction of the metal pipe material <NUM>. Similarly, the end portion of the metal pipe material <NUM> on the electrode <NUM> side protrudes toward the seal member <NUM> beyond a boundary between the concave grooves 17a and the tapered concave surfaces 17b of the electrodes <NUM> in the extending direction of the metal pipe material <NUM>. In addition, lower surfaces of the upper electrodes <NUM> and <NUM> and upper surfaces of the lower electrodes <NUM> and <NUM> are in contact with each other. However, the present disclosure is not limited to a configuration in which the electrodes <NUM> and <NUM> come into close contact with the entire peripheries of the both end portions of the metal pipe material <NUM>, and the electrodes <NUM> and <NUM> may be in contact with a part of the metal pipe material <NUM> in the peripheral direction.

Next, the controller <NUM> controls the heating mechanism <NUM> so as to heat the metal pipe material <NUM>. Specifically, the controller <NUM> controls the power supply portion <NUM> of the heating mechanism <NUM> such that electric power is supplied. As a result, the electric power transmitted to the lower electrodes <NUM> and <NUM> through the power supply line <NUM> is supplied to the upper electrodes <NUM> and <NUM> that sandwiches the metal pipe material <NUM> and the metal pipe material <NUM>, and due to a resistance of the metal pipe material <NUM>, the metal pipe material <NUM> itself generates heat by Joule heat. In other words, the metal pipe material <NUM> enters an energized and heated state.

Next, the controller <NUM> controls the drive mechanism <NUM> such that the forming die <NUM> is closed with respect to the heated metal pipe material <NUM>. Accordingly, the cavity <NUM> of the lower die <NUM> and the cavity <NUM> of the upper die <NUM> are combined with each other such that the metal pipe material <NUM> is disposed in a cavity portion between the lower die <NUM> and the upper die <NUM> and is sealed.

Thereafter, by operating the cylinder unit <NUM> of the gas supply mechanism <NUM>, the seal member <NUM> advances such that both ends of the metal pipe material <NUM> are sealed. At this time, as shown in <FIG>, the seal member <NUM> is pressed against the end portion of the metal pipe material <NUM> on the electrode <NUM> side, and accordingly, a portion that protrudes toward the seal member <NUM> beyond the boundary between the concave grooves 18a and the tapered concave surfaces 18b of the electrodes <NUM> is deformed into a funnel shape to follow the tapered concave surfaces 18b. Similarly, the seal member <NUM> is pressed against the end portion of the metal pipe material <NUM> on the electrode <NUM> side, and accordingly, a portion that protrudes toward the seal member <NUM> beyond the boundary between the concave grooves 17a and the tapered concave surfaces 17b of the electrodes <NUM> is deformed into a funnel shape to follow the tapered concave surfaces 17b. After the sealing is completed, a high-pressure gas is blown into the metal pipe material <NUM> and the heated and softened metal pipe material <NUM> is formed so as to follow the shape of the cavity portion.

The metal pipe material <NUM> is heated to a high temperature (approximately <NUM>) and softened, and accordingly, the gas supplied into the metal pipe material <NUM> thermally expands. Therefore, for example, compressed air may be used as the gas to be supplied such that expansion is easily performed by compressed air obtained by thermally expanding the metal pipe material <NUM> of <NUM>.

An outer peripheral surface of the blow-formed and expanded metal pipe material <NUM> comes into contact with the cavity <NUM> of the lower die <NUM> so as to be rapidly cooled and comes into contact with the cavity <NUM> of the upper die <NUM> so as to be rapidly cooled (since the upper die <NUM> and the lower die <NUM> have a large heat capacity and are controlled to a low temperature, when the metal pipe material <NUM> comes into contact with the upper die <NUM> and the lower die <NUM>, the heat of the pipe surface is taken to the die side at once) at the same time, and thus, quenching is performed. The above-described cooling method is referred to as die contact cooling or die cooling. Immediately after being rapidly cooled, austenite transforms into martensite (hereinafter, transformation from austenite to martensite is referred to as martensitic transformation). The cooling speed is set to be low in a second half of the cooling, and thus, martensite transforms into another structure (such as troostite, sorbite, or the like) due to recuperation. Therefore, it is not necessary to separately perform tempering treatment. In the present embodiment, the cooling may be performed by supplying a cooling medium into, for example, the cavity <NUM>, instead of or in addition to the die cooling. For example, cooling may be performed by bringing the metal pipe material <NUM> into contact with the dies (the upper die <NUM> and the lower die <NUM>) until a temperature at which the martensitic transformation starts is reached, and the dies may be opened thereafter with a cooling medium (cooling gas) blown onto the metal pipe material <NUM> such that martensitic transformation occurs.

As described above, a metal pipe having an approximately rectangular main body is obtained by performing cooling after the blow forming with respect to the metal pipe material <NUM> and by performing die opening.

Next, with reference to <FIG> and <FIG>, a forming system <NUM> according to the present embodiment will be described. <FIG> is a schematic plan view of the forming system <NUM>. <FIG> is a schematic perspective view of a main part of the forming system <NUM>.

As shown in <FIG>, the forming system <NUM> includes the forming apparatus <NUM>, a first placing unit <NUM> on which the metal pipe material <NUM> is placed, a second placing unit <NUM> on which the formed metal pipe is placed, a transport mechanism <NUM> for transporting the metal pipe material <NUM> or the metal pipe, and the controller <NUM>. As shown in <FIG>, the forming system <NUM> further includes a floor surface <NUM> on which a part of the forming apparatus <NUM> is placed, and an underground pit <NUM> (structure) provided below the floor surface <NUM>. In <FIG>, for the sake of description, a part of the forming apparatus <NUM> and a part of the floor surface <NUM> are omitted. Hereinafter, a direction in which the electrode <NUM> and the electrode <NUM> face each other in the horizontal direction is referred to as "X-axis direction", a direction perpendicular to the X-axis direction in the horizontal direction is referred to as "Y-axis direction", and the up-down direction is referred to as "Z-axis direction".

The first placing unit <NUM> is positioned on one side of the center of the forming apparatus <NUM> in the direction X, and is positioned on one side of the center of the forming apparatus <NUM> in the direction Y. The second placing unit <NUM> is positioned on the other side of the center of the forming apparatus <NUM> in the direction X, and is positioned on one side of the center of the forming apparatus <NUM> in the direction Y. The transport mechanism <NUM> is a mechanism for installing the metal pipe material <NUM> on the forming apparatus <NUM> and taking out the formed metal pipe, and has a main body 103a and a robot arm 103b. The transport mechanism <NUM> is positioned between the first placing unit <NUM> and the second placing unit <NUM> in the direction X. In the direction Y, the main body 103a is separated from the forming apparatus <NUM> by the first placing unit <NUM> and the second placing unit <NUM>, but is not limited thereto.

The floor surface <NUM> is a placement surface on which the base stage <NUM> of the forming apparatus <NUM>, the forming die <NUM>, the gas supply mechanism <NUM>, the drive mechanism <NUM>, and the like are placed. The floor surface <NUM> may be, for example, the floor itself of a factory or the like, or the surface of a table provided on the floor. The floor surface <NUM> is provided with an opening <NUM> through which the power supply line 52A and 52B are inserted. The underground pit <NUM> is an accommodation space for accommodating a part of the forming apparatus <NUM>. At least a part of the underground pit <NUM> overlaps a portion of the forming apparatus <NUM> positioned on the floor surface <NUM>. The space on the floor surface <NUM> and the underground pit <NUM> are connected to each other through the opening <NUM>. Although not shown, the entrance and exit of the underground pit <NUM> is provided at a location that does not overlap with the forming apparatus <NUM> in the direction Z. The opening <NUM> may be closed by a lid or the like.

The power supply portion <NUM> in the heating mechanism <NUM> is a device that supplies electric power to the electrodes <NUM> and <NUM> through the power supply lines 52A and 52B. The power supply portion <NUM> is positioned on the other side of the center of the forming apparatus <NUM> in the direction Y, and is accommodated in the underground pit <NUM>. The power supply portion <NUM> is disposed at a position that does not overlap the base stage <NUM> in the direction Z.

The power supply line 52A has a plurality of electric wires 52a and a busbar 52b (conductor). The plurality of electric wires 52a are a wire for connecting the electrode <NUM> and the busbar 52b. Therefore, one terminal of the electric wire 52a is connected to the electrode <NUM>, and the other terminal of the electric wire 52a is connected to the busbar 52b. A large part of the electric wire 52a is routed on the floor surface <NUM>. A part of the electric wire 52a including the other terminal is disposed in the underground pit <NUM> through the opening <NUM> provided in the floor surface <NUM>. The busbar 52b is a conductive structure that connects the power supply portion <NUM> and the electric wire 52a, and is accommodated in the underground pit <NUM>. The busbar 52b is a conductor made of a metal such as copper or an alloy, and is a location where the heat can be generated most in the power supply line 52A. The busbar 52b is placed on a pedestal <NUM> fixed in, for example, the underground pit <NUM>. The busbar 52b is disposed at a position that does not overlap the base stage <NUM> in the direction Z. The busbar 52b has a substantially L-shaped main body <NUM> and a terminal unit <NUM> to which the electric wire 52a is attached. The terminal unit <NUM> is attached to the floor surface <NUM> side of the main body <NUM> in the direction Z.

The power supply line 52B has a plurality of electric wires 52c and a busbar 52d (conductor). The plurality of electric wires 52c are wires for connecting the electrode <NUM> and the busbar 52d. Therefore, one terminal of the electric wire 52c is connected to the electrode <NUM>, and the other terminal of the electric wire 52c is connected to the busbar 52d. A large part of the electric wire 52c is routed on the floor surface <NUM>. A part of the electric wire 52c including the other terminal is disposed in the underground pit <NUM> through the opening <NUM> provided in the floor surface <NUM>. The busbar 52d is a conductive structure that connects the power supply portion <NUM> and the electric wire 52c, and similar to the busbar 52b, the busbar 52d is accommodated in the underground pit <NUM>. The busbar 52d is a conductor made of a metal such as copper or an alloy, and is a location where the heat can be generated most in the power supply line 52B. The busbar 52d is placed on a pedestal <NUM> fixed in, for example, the underground pit <NUM>. The busbar 52d is disposed at a position that does not overlap the base stage <NUM> in the direction Z. The busbar 52d has a substantially L-shaped main body <NUM> and a terminal unit <NUM> to which the electric wire 52c is attached. The terminal unit <NUM> is attached to the floor surface <NUM> side of the main body <NUM> in the direction Z.

As shown in <FIG>, an exhaust pipe <NUM> is attached to the gas supply mechanism <NUM> to which the power supply line 52A is connected, and an exhaust pipe <NUM> is attached to the gas supply mechanism <NUM> to which the power supply line 52B is connected. The exhaust pipe <NUM> is one of the configuration requirements of the exhaust mechanism 200A, and has a main portion <NUM> and a tip part <NUM>. The exhaust pipe <NUM> is one of the configuration requirements of the exhaust mechanism 200B, and has a main portion <NUM> and a tip part <NUM>. Each of the main portions <NUM> and <NUM> is routed on the floor surface <NUM>. Each of the tip parts <NUM> and <NUM> is accommodated in the underground pit <NUM> through the opening <NUM>. In the underground pit <NUM>, the tip part <NUM> is disposed along the outer peripheral surface of the busbar 52b, and the tip part <NUM> is disposed along the outer peripheral surface of the busbar 52d. In the present embodiment, the tip part <NUM> is disposed along the both the portion that extends along the direction Z in the main body <NUM> of the busbar 52b and the portion that extends along the direction X in the main body <NUM>. Similar to the tip part <NUM>, the tip part <NUM> is disposed along both the portion that extends along the direction Z in the main body <NUM> of the busbar 52d and the portion that extends along the direction X in the main body <NUM>. Although omitted in <FIG>, the exhaust pipe <NUM> is branched from the gas supply line L1 and the exhaust pipe <NUM> is branched from the gas supply line L2.

The exhaust pipes <NUM> and <NUM> are made of a material that can withstand the high-pressure gas, and are, for example, metal or alloy pipes. In this case, the exhaust pipes <NUM> and <NUM> may exhibit conductivity. From the viewpoint of suppressing an increase in resistance of the power supply line 52A, the tip part <NUM> is separated from the busbar 52b. From the viewpoint of preventing contact between the tip part <NUM> and the busbar 52b, an insulating material or the like may be provided between the tip part <NUM> and the busbar 52b. Similarly, the tip part <NUM> is separated from the busbar 52d.

Here, with reference to <FIG>, the disposition of the busbars 52b and 52d in the underground pit <NUM> and the tip parts <NUM> and <NUM> will be described. <FIG> are schematic views showing the relationship between the busbars 52b and 52d and the tip parts <NUM> and <NUM>. <FIG> is a view showing a state where the busbar 52b and the tip part <NUM> are further separated from each other. In <FIG>, safety valves <NUM> and <NUM> are attached to the tip parts <NUM> and <NUM>, respectively. The safety valves <NUM> and <NUM> may be provided in the underground pit <NUM> or may be provided on the floor surface <NUM>.

As described above, the tip part <NUM> is disposed along the busbar 52b, and the tip part <NUM> is disposed along the busbar 52b. In addition, the exhaust port <NUM> provided at the tip part <NUM> is provided so as to face the busbar 52b. Accordingly, the gas exhausted from the exhaust port <NUM> is blown to the busbar 52b. In the present embodiment, the tip part <NUM> is provided with a plurality of exhaust ports <NUM>, but the present disclosure is not limited thereto. Although not illustrated, the exhaust port provided at the tip part <NUM> is provided so as to face the busbar 52d.

In the forming system <NUM>, the controller <NUM> is incorporated in, for example, a fixed control panel, and is positioned on one side of the center of the forming apparatus <NUM> in the direction Y. Therefore, the controller <NUM> is positioned on the opposite side of the heating mechanism <NUM> with the forming apparatus <NUM> in the direction Y therebetween. In addition, the controller <NUM> is positioned on the opposite side of the tip parts <NUM> and <NUM> of the exhaust pipes <NUM> and <NUM> with the forming apparatus <NUM> in the direction Y therebetween. Accordingly, in a case where the worker uses the control panel, it is less likely to receive the influence of the heat generated from the heating mechanism <NUM> and gas exhausted from the exhaust mechanisms 200A and 200B. The controller <NUM> is positioned on the opposite side of the forming apparatus <NUM> with the transport mechanism <NUM> in the direction Y therebetween. Accordingly, in a case where the worker uses the control panel, the worker of the transport mechanism <NUM> is not hindered by the worker.

Next, the effects of the forming system <NUM> according to the present embodiment will be described. According to the forming system <NUM>, the exhaust port <NUM> of the exhaust mechanism 200A is positioned in the internal space of the underground pit <NUM> which is a structure having an internal space. Therefore, the discharge noise generated when the high-pressure gas is exhausted from the exhaust port <NUM> is generated in the underground pit <NUM>. In this case, the underground pit <NUM> functions as a silencer for the discharge noise. Therefore, the discharge noise is less likely to be noisy to a worker and the like who works around the forming apparatus <NUM>. Therefore, by using the above-described forming system <NUM>, it is possible to take countermeasures against the discharge noise. The structure that functions as a silencer is provided in the underground pit, which contributes to reducing the space of the entire forming apparatus.

According to the above-described forming system <NUM>, the tip part <NUM> of the exhaust pipe <NUM> included in the exhaust mechanism 200A and provided with the exhaust port <NUM> is positioned in the underground pit <NUM> provided at the lower portion of the floor surface <NUM>. Accordingly, the discharge noise generated when the high-pressure gas is exhausted from the exhaust port <NUM> is generated in the underground pit <NUM>. In addition, the tip part <NUM> of the exhaust pipe <NUM> included in the exhaust mechanism 200B and provided with the exhaust port is also positioned in the underground pit <NUM>. Accordingly, the discharge noise generated when the high-pressure gas is exhausted from the exhaust port provided at the tip part <NUM> is generated in the underground pit <NUM>. Therefore, the discharge noise is less likely to be noisy to the worker and the like who is on the floor surface <NUM> and works around the forming apparatus <NUM>. Therefore, by using the forming system <NUM>, it is possible to take countermeasures against the discharge noise.

In the forming system <NUM> of the present embodiment, the forming apparatus <NUM> includes electrodes <NUM> and <NUM> for heating the metal pipe material <NUM> and the power supply lines 52A and 52B connected to the electrodes <NUM> and <NUM>, the power supply line 52A has the busbar 52b accommodated in the underground pit <NUM>, and in the underground pit <NUM>, the exhaust port <NUM> faces the busbar 52b. Therefore, the busbar 52b heated by energizing the electrode <NUM> can be cooled by the gas exhausted from the exhaust port <NUM>. In addition, the power supply line 52B has the busbar 52d accommodated in the underground pit <NUM>, and in the underground pit <NUM>, the exhaust port provided at the tip part <NUM> faces the busbar 52d. Therefore, the busbar 52d heated by energizing the electrode <NUM> can also be cooled by the gas exhausted from the exhaust port.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiment. For example, each power supply line may not have a busbar. The tip part is disposed along the outer peripheral surface of the busbar may be disposed along the inner peripheral surface of the busbar.

In the above-described embodiment, in the underground pit, the exhaust port of the exhaust pipe faces the busbar, but the present disclosure is not limited thereto. For example, in a case where the busbar is cooled by using a water-cooled cable or the like, the exhaust port of the exhaust pipe may not face the busbar. In other words, it is not necessary to cool the busbar with the gas exhausted from the exhaust port.

In the above-described embodiment, an underground pit under the floor is used as a structure that functions as a silencer. However, the structure is not particularly limited as long as an internal space in which the gas discharge unit can be disposed is provided and it is possible to block the sound generated in the internal space from leaking to the outside. For example, as shown in <FIG>, the forming system may have a tank <NUM> as a structure. The exhaust port <NUM> of the exhaust mechanisms 200A and 200B are positioned in the internal space of the tank <NUM>. When using the tank <NUM>, the position of the tank <NUM> is not particularly limited. For example, the tank <NUM> may be disposed on the floor surface <NUM> instead of the underground pit.

For example, as a structure according to a comparative example, there is a structure in which a muffler is provided at the tip of the gas discharge unit to provide soundproofing. However, in a case where the exhaust pressure is high, there is a possibility that such a muffler cannot withstand the exhaust pressure, and is damaged. On the other hand, since the tank <NUM> has a sufficiently large internal space, there is a low possibility that the tank <NUM> is damaged even in a case where the exhaust pressure is high, and can be used for a long period of time. Such an effect can be similarly obtained in a case where the soundproofing is performed in the underground pit.

In the above-described embodiment, in addition to the forming apparatus, the forming system includes the first placing unit, the second placing unit, the transport mechanism, and the like, but the present disclosure is not limited thereto. For example, the forming system may not include at least one of the first placing unit, the second placing unit, and the transport mechanism. Further, the first placing unit, the second placing unit, the transport mechanism, and the like are not limited to the configurations shown in the above-described embodiment.

Claim 1:
A forming system (<NUM>) for forming a metal pipe having a hollow shape, the system comprising:
a forming apparatus (<NUM>) including a gas supply portion (<NUM>) that supplies gas into a heated metal pipe material when forming the metal pipe, and a discharge unit (200A, 200B) that discharges the gas which is in the formed metal pipe;
a floor surface (<NUM>) on which the forming apparatus is placed; and
an underground pit (<NUM>) provided at a lower portion of the floor surface,
characterized in that
an exhaust port (<NUM>) of the discharge unit is positioned in an internal space of a structure having the internal space, and
the discharge unit includes an exhaust pipe (<NUM>, <NUM>) positioned in the underground pit as the structure and provided with the exhaust port.