JP2022144636A - Electric heating system and electrode - Google Patents

Abstract

To provide an electric heating system and an electrode capable of improving the certainty of holding a bent metal pipe material.SOLUTION: An electric heating system 100 includes a measuring device 110 that measures the bending shape of a metal pipe material 40. Even when the bending of the metal pipe material 40 varies, the measuring device 110 can grasp in advance how much the metal pipe material 40 to be held is bent. An electrode 10 adjusts its posture with respect to the metal pipe material 40 on the basis of the measurement result by the measuring device 110. Therefore, the posture of the electrode 10 can be appropriately adjusted according to the bent shape of the metal pipe material 40 to be held such that the metal pipe material can be easily held. Thereby, the certainty of holding the bent metal pipe material 40 can be improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electric heating system for metal pipe material.

Conventionally, what was described in patent document 1 is known as an electric heating system which hold|maintains a metal pipe material with an electrode and electrically heats it. The electric heating system described in Patent Literature 1 performs electric heating by holding a metal pipe material with an electrode and applying an electric current from the electrode to the metal pipe material. The heated metal pipe material is molded by a molding die.

Japanese Patent Application Laid-Open No. 2009-220141

Here, as the metal pipe material, there is a case where a material that has undergone bending in advance is adopted (preform). In this case, the electrodes should hold the metal pipe material in a bent state. However, variations may occur in the bending shape of the metal pipe material. In this way, if the bending of the metal pipe material varies, the electrodes may not be able to hold the metal pipe material well.

The present invention has been made to solve such problems, and an object of the present invention is to provide an electric heating system and an electrode that can improve the certainty of holding a bent metal pipe material.

An electric heating system according to one aspect of the present invention includes an electrode that holds a bent metal pipe material and electrically heats the metal pipe material, and a shape grasping unit that grasps the shape of the metal pipe material. adjusts the posture with respect to the metal pipe material based on the shape grasped by the shape grasping unit.

The electric heating system includes a shape grasping section that grasps the shape of the metal pipe material. Thereby, even if variation occurs in bending of the metal pipe material, the shape grasping unit can grasp in advance how much the metal pipe material to be held is bent. And an electrode adjusts the attitude|position with respect to a metal pipe material based on the shape grasped|ascertained by the shape grasping part. Therefore, the electrode can be appropriately adjusted in posture so as to be easily held according to the bent shape of the metal pipe material to be held. This can improve the certainty of holding the bent metal pipe material.

The shape grasping part may measure the distance from the sensor for at least three points in the longitudinal direction of the metal pipe material. Thus, the bending shape of the metal pipe material can be accurately grasped by the shape grasping part measuring the distances of at least three points.

The shape grasping part may grasp the shape of the metal pipe material in a state in which the ends of the metal pipe material are positioned in the longitudinal direction. By positioning the end portion in this way, the shape grasping section can easily grasp the bending shape of the metal pipe material on the basis of the end portion.

The electrode may have a groove formed in the end surface and in contact with the outer peripheral surface of the metal pipe material, and the groove may have a wide surface in which the width of the groove increases toward the end surface. In this case, even if the electrodes and the metal pipe material are slightly misaligned, the wide surface can guide the metal pipe material.

The electrode according to the present invention is an electrode that holds a bent metal pipe material and electrically heats the metal pipe material. Based on the shape grasped by the shape grasping unit that grasps the shape of the metal pipe material, Adjust the attitude to the metal pipe material.

According to the electrode according to the present invention, it is possible to obtain the same actions and effects as those of the above-described electrical heating system.

ADVANTAGE OF THE INVENTION According to this invention, the electric heating system which can improve the certainty of holding|maintenance of bent metal pipe material, and an electrode can be provided.

1 is a schematic configuration diagram of a molding system provided with an electric heating system according to an embodiment of the present invention; FIG. 2 is a schematic diagram of the molding apparatus shown in FIG. 1; FIG. It is a figure which shows the appearance of bent metal pipe material. 4 is a schematic configuration diagram of a heating and expansion unit; FIG. It is a top view of a measuring device. It is a figure which shows the structure of an electrode.

Preferred embodiments of the present invention will be described below with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

FIG. 1 is a schematic configuration diagram of a molding system 150 including an electric heating system 100 according to an embodiment of the present invention. The molding system 150 includes a molding device 1 having an electrode 10 , a measuring device 110 (shape grasping section), and a conveying device 120 . The molding apparatus 1 includes a heating expansion unit 50 in which the electrode 10 and the fluid supply section 6 are unitized. The electric heating system 100 includes a heating expansion unit 50 , a measuring device 110 and a conveying device 120 .

First, the configuration of the molding apparatus 1 will be described with reference to FIG. FIG. 2 is a schematic diagram of the molding apparatus 1 shown in FIG. As shown in FIG. 2, the molding apparatus 1 is an apparatus for molding a metal pipe having a hollow shape by blow molding. In this embodiment, the molding device 1 is installed on a horizontal plane. The molding apparatus 1 includes a molding die 2 (molding die), a drive mechanism 3 , a holding section 4 , a heating section 5 , a fluid supply section 6 , a cooling section 7 and a control section 8 . In this specification, a metal pipe refers to a hollow article after completion of molding by the molding apparatus 1, and a metal pipe material 40 refers to a hollow article before completion of molding by the molding apparatus 1. The metal pipe material 40 is a hardenable steel type pipe material. Moreover, the direction which the metal pipe material 40 extends at the time of shaping|molding among horizontal directions may be called an "extending direction", and the direction orthogonal to an extending direction may be called a "horizontal direction."

The molding die 2 is a die for molding the metal pipe material 40 into a metal pipe, and includes a lower die 11 and an upper die 12 facing each other in the vertical direction. The lower die 11 and the upper die 12 are constructed from steel blocks. The mold 11 on the lower side is fixed to the base 13 via a die holder or the like. The upper die 12 is fixed to the slide of the drive mechanism 3 via a die holder or the like.

The drive mechanism 3 is a mechanism that moves at least one of the lower mold 11 and the upper mold 12 . In FIG. 2 , the drive mechanism 3 has a configuration that moves only the upper mold 12 . The drive mechanism 3 includes a slide 21 that moves the upper die 12 so that the lower die 11 and the upper die 12 are joined together, and a pull-back cylinder as an actuator that generates a force to lift the slide 21 upward. 22 , a main cylinder 23 as a drive source that pressurizes the slide 21 downward, and a drive source 24 that applies a drive force to the main cylinder 23 .

The holding part 4 is a mechanism that holds the metal pipe material 40 arranged between the lower mold 11 and the upper mold 12 . The holding portion 4 is configured by electrodes 10 on both sides in the extending direction. Specifically, the holding portion 4 includes a lower electrode 26 and an upper electrode 27 that hold the metal pipe material 40 at one end side in the extending direction of the molding die 2 and the other end in the extending direction of the molding die 2 . a lower electrode 26 and an upper electrode 27 holding metal pipe material 40 on the sides. The lower electrode 26 and the upper electrode 27 on both sides in the extending direction hold the metal pipe material 40 by sandwiching the end portions of the metal pipe material 40 from above and below. The upper surface of the lower electrode 26 and the lower surface of the upper electrode 27 are formed with grooves having a shape corresponding to the outer peripheral surface of the metal pipe material 40 . A driving mechanism (not shown) is provided for the lower electrode 26 and the upper electrode 27 so that they can move independently in the vertical direction.

The heating unit 5 heats the metal pipe material 40 . The heating unit 5 is a mechanism that heats the metal pipe material 40 by energizing the metal pipe material 40 . The heating unit 5 heats the metal pipe material 40 between the lower mold 11 and the upper mold 12 while the metal pipe material 40 is separated from the lower mold 11 and the upper mold 12. Heat 40; The heating unit 5 includes the electrodes 10 on both sides in the extending direction, that is, the lower electrode 26 and the upper electrode 27 on both sides in the extending direction, and current is passed through the electrodes 26 and 27 to the metal pipe material. a power supply 28;

The fluid supply unit 6 is a mechanism for supplying high-pressure fluid into the metal pipe material 40 held between the lower mold 11 and the upper mold 12 . The fluid supply unit 6 supplies high-pressure fluid to the metal pipe material 40 that has been heated by the heating unit 5 to a high temperature state, thereby expanding the metal pipe material 40 . The fluid supply units 6 are provided at both ends of the molding die 2 in the extending direction. The fluid supply unit 6 includes a nozzle 31 that supplies fluid from the opening at the end of the metal pipe material 40 to the inside of the metal pipe material 40, and a drive that moves the nozzle 31 forward and backward with respect to the opening of the metal pipe material 40. It comprises a mechanism 32 and a source 33 for supplying high pressure fluid into the metal pipe material 40 through the nozzle 31 . The drive mechanism 32 brings the nozzle 31 into close contact with the end of the metal pipe material 40 while ensuring sealing performance during fluid supply and exhaust, and separates the nozzle 31 from the end of the metal pipe material 40 at other times. The fluid supply unit 6 may supply gas such as high-pressure air or inert gas as the fluid. Further, the fluid supply unit 6 and the holding unit 4 having a mechanism for vertically moving the metal pipe material 40 and the heating unit 5 may be included in the same device.

The cooling part 7 is a mechanism for cooling the molding die 2 . By cooling the molding die 2 , the cooling section 7 can rapidly cool the metal pipe material 40 when the expanded metal pipe material 40 comes into contact with the molding surface of the molding die 2 . The cooling unit 7 includes flow paths 36 formed inside the lower mold 11 and the upper mold 12 and a water circulation mechanism 37 that supplies and circulates cooling water to the flow paths 36 .

The control unit 8 is a device that controls the molding apparatus 1 as a whole. The control unit 8 controls the drive mechanism 3 , the holding unit 4 , the heating unit 5 , the fluid supply unit 6 and the cooling unit 7 . The control unit 8 repeats the operation of molding the metal pipe material 40 with the molding die 2 .

Specifically, the control unit 8, for example, controls the timing of transport from a transport device such as a robot arm to place the metal pipe material 40 between the lower mold 11 and the upper mold 12 in the open state. Deploy. Alternatively, the control unit 8 may wait for the operator to manually place the metal pipe material 40 between the lower mold 11 and the upper mold 12 . In addition, the control unit 8 supports the metal pipe material 40 with the lower electrodes 26 on both sides in the extending direction, and then lowers the upper electrode 27 so that the metal pipe material 40 is sandwiched. to control. Moreover, the control part 8 controls the heating part 5, and energizes and heats the metal pipe material 40. As shown in FIG. As a result, an axial current flows through the metal pipe material 40, and the electrical resistance of the metal pipe material 40 itself causes the metal pipe material 40 itself to generate heat due to Joule heat.

The control unit 8 controls the drive mechanism 3 to lower the upper mold 12 and bring it closer to the lower mold 11 to close the mold 2 . On the other hand, the control unit 8 controls the fluid supply unit 6 to seal the openings at both ends of the metal pipe material 40 with the nozzles 31 and supply the fluid. As a result, the metal pipe material 40 softened by heating expands and comes into contact with the molding surface of the molding die 2 . And the metal pipe material 40 is shape|molded so that the shape of the shaping|molding surface of the shaping|molding die 2 may be followed. When the metal pipe material 40 comes into contact with the molding surface, the metal pipe material 40 is quenched by being rapidly cooled by the cooling part 7 with the molding die 2 .

Here, as shown in FIG. 3, the forming apparatus 1 forms the pre-bent metal pipe material 40 . FIG. 3(a) is a schematic view of the state of the metal pipe material 40 placed in the molding die 2 as viewed from above. As shown in FIG. 3(a), the metal pipe material 40 has a curved shape in a horizontal plane. Specifically, the metal pipe material 40 has a straight portion 41 that extends linearly at both ends in the longitudinal direction, and a bent portion 42 that is curved in an arc shape with a predetermined curvature at the central position in the longitudinal direction. . The electrodes 10 on both sides in the longitudinal direction hold the metal pipe material 40 in an inclined state within the horizontal plane according to the angle of each straight portion 41 . Here, as indicated by the phantom lines in FIG. 3B, the electrode 10 may hold the metal pipe material 40 having different bending shapes due to the influence of variations in the bending process. The electrode 10 is configured so that its posture can be adjusted with respect to the metal pipe material 40 so as to cope with the situation.

Next, a mechanism for adjusting the posture of the electrode 10 with respect to the metal pipe material 40 will be described with reference to FIG. Specifically, the heating/expansion unit 50 has a mechanism for adjusting the posture of the electrode 10 . Moreover, when the posture of the electrode 10 is changed, the posture of the fluid supply section 6 also needs to be changed. Therefore, the heating/expansion unit 50 adjusts the postures of the electrode 10 and the fluid supply section 6 . Here, in FIG. 4, an XYZ coordinate system is set for explanation. The X-axis direction indicates the vertical direction. The upper side indicates the positive side in the X-axis direction. The Z-axis direction indicates the horizontal direction of the molding device 1 . One side in the horizontal direction is defined as the positive side in the Z-axis direction. The Y-axis direction indicates the extending direction of the molding device 1 . The molding die 2 side (see FIG. 2) is defined as the positive side in the Y-axis direction. FIG. 4(a) is a view of the heating/expansion unit 50 viewed from the positive side toward the negative side in the X-axis direction. FIG. 4B is a diagram of the heating and expansion unit 50 viewed from the positive side toward the negative side in the Z-axis direction. FIG. 4C is a diagram of the heating and expansion unit 50 viewed from the positive side toward the negative side in the Y-axis direction.

The heating/expansion unit 50 includes a base portion 51 that movably supports the electrode 10 and the fluid supply portion 6 . The base portion 51 includes a Z-axis stage 52, an X-axis stage 53, and a Y-axis stage 54 in order from the bottom. The Z-axis stage 52 is a stage that adjusts the positions of the electrode 10 and the fluid supply section 6 in the Z-axis direction. The Z-axis stage 52 is connected to a Z-axis cylinder 56 that can extend and contract in the Z-axis direction. Therefore, when the Z-axis cylinder 56 drives the Z-axis stage 52 , the electrode 10 and the fluid supply section 6 are moved in the Z-axis direction via the X-axis stage 53 and the Y-axis stage 54 . The X-axis stage 53 is a stage that adjusts the positions of the electrodes 10 and the fluid supply section 6 in the X-axis direction. The X-axis stage 53 is connected to an X-axis cylinder 57 that can expand and contract in the X-axis direction. Therefore, the X-axis cylinder 57 drives the X-axis stage 53 to move the electrode 10 and the fluid supply unit 6 in the X-axis direction via the Y-axis stage 54 . The Y-axis stage 54 is a stage that adjusts the positions of the electrodes 10 and the fluid supply section 6 in the Y-axis direction. A fluid supply unit 6 and electrodes 10 are provided on the upper surface of the Y-axis stage 54 . The Y-axis stage 54 is connected to a Y-axis cylinder 58 that can expand and contract in the Y-axis direction. Therefore, the Y-axis cylinder 58 drives the Y-axis stage 54 to move the electrode 10 and the fluid supply unit 6 in the Y-axis direction.

Also, the electrode 10 is attached to the Y-axis stage via a rotating shaft 60 . Therefore, the rotation of the rotating shaft 60 rotates the electrode 10 and adjusts the angle with respect to the Y-axis direction. The fluid supply unit 6 is attached to the Y-axis stage 54 via a rotating shaft 61 . Therefore, the rotational driving of the rotating shaft 61 rotates the fluid supply unit 6 and adjusts the angle with respect to the Y-axis direction. It should be noted that the fluid supply unit 6 can be turned around the rotation shaft 60 of the electrode 10 by the turning unit 62 . Therefore, when the electrode 10 changes the angle, the fluid supply unit 6 changes the angle by rotating the rotating shaft 61 according to the angle, and the turning unit 62 rotates the metal pipe material 40 held by the electrode 10 to the nozzle. 31 to a position where it can be connected.

Next, the measuring device 110 will be described with reference to FIGS. 1 and 5. FIG. The measuring device 110 is a device for grasping the shape of the metal pipe material 40 . In this embodiment, the measuring device 110 is a device that measures the bending shape of the metal pipe material 40 . As shown in FIGS. 1 and 5, the measuring device 110 includes a base portion 71, sensors 70A, 70B, and 70C for measuring distances, and a positioning jig 72. As shown in FIGS. The base portion 71 is a member on which the metal pipe material 40 to be measured is arranged. Sensors 70A, 70B, and 70C are sensors that measure the distance to each portion of metal pipe material 40 . Thereby, the measuring device 110 measures distances from the sensors 70A, 70B, and 70C at three points in the longitudinal direction of the metal pipe material 40 . The positioning jig 72 is a jig for positioning one end 40a of the metal pipe material 40 in the longitudinal direction. Thereby, the measuring device 110 measures the metal pipe material 40 with the end portion 40a positioned in the longitudinal direction of the metal pipe material 40 .

Specifically, as shown in FIG. 5, the sensors 70A, 70B, 70C are arranged at positions separated from the metal pipe material 40. As shown in FIG. The sensors 70A, 70B, 70C are arranged along the longitudinal direction of the metal pipe material 40 so as to be able to measure positions different from each other. The sensor 70A measures the distance between the straight portion 41 on the one end portion 40a side and the vicinity of the boundary portion with the bent portion 42 . Sensor 70B measures the distance to the vicinity of the top of bent portion 42 . The sensor 70A measures the distance between the straight portion 41 on the other end portion 40b side and the vicinity of the boundary portion with the bent portion 42 . Each sensor 70A, 70B, 70C outputs the measurement result to the shape calculator 76 (see FIG. 1). The shape calculator 76 calculates, for example, the bending angle θ based on the measurement results of the sensors 70A, 70B, and 70C.

As shown in FIG. 5, the positioning jig 72 includes an end support member 72a that positions the metal pipe material 40 by contacting the end portion 40a, and a lateral support member 72a that supports the straight portion 41 by sandwiching it from the lateral side. and side support members 72b and 72c. The positions of the positioning jig 72 and the sensors 70A, 70B, 70C are fixed to each other. Accordingly, the positions of the positioned end portion 40a of the metal pipe material 40 and the sensors 70A, 70B, 70C are also fixed. Accordingly, since the position of the end portion 40a is fixed and the shape calculation portion 76 grasps the bending angle θ, the position of the straight portion 41 on the side of the other end portion 40b can be calculated.

As shown in FIG. 1 , the shape calculator 76 transmits the measurement result of the measuring device 110 to the controller 8 . The controller 8 then controls the operation of the heating/expansion unit 50 based on the measurement results calculated by the shape calculator 76 . Thereby, the heating/expansion unit 50 adjusts the posture with respect to the metal pipe material 40 based on the shape grasped by the measuring device 110, which is the measurement result of the sensors 70A, 70B, and 70C in this embodiment.

As shown in FIG. 1, the conveying device 120 is a device for conveying the metal pipe material 40, which has been measured by the measuring device 110, into the mold. The transport device 120 is configured by a robot arm.

Next, the shape of the electrode 10 will be described with reference to FIG. Although only the upper electrode 27 is shown in FIG. 6, the lower electrode 26 may also have a similar configuration. As shown in FIG. 6A, the end face 27a of the upper electrode 27 has a groove portion 80 that contacts the outer peripheral face of the metal pipe material 40. As shown in FIG. The groove portion 80 has a semicircular cross section in conformity with the outer shape of the metal pipe material 40 . Thereby, the groove part 80 can contact the outer peripheral surface of the metal pipe material 40 over a wide range. Further, as shown in FIG. 6B, the upper electrode 27 may have a groove portion 81 having a wide surface 81b that widens toward the end surface 27a. The groove part 81 has the curved surface 81a curved with the same curvature as the metal pipe material 40, and a pair of wide surface 81b in the bottom side. The groove part 81 guides the metal pipe material 40 relatively to the bottom side by the wide surface 81b, and contacts the outer peripheral surface by the curved surface 81a on the bottom side.

Next, functions and effects of the electric heating system 100 according to the present embodiment will be described.

The electric heating system 100 includes a measuring device 110 for grasping the shape of the metal pipe material 40, that is, measuring the bending shape. Thereby, even if the bending of the metal pipe material 40 varies, the measuring device 110 can grasp in advance how much the metal pipe material 40 to be held is bent. And the electrode 10 adjusts the attitude|position with respect to the metal pipe material 40 based on the measurement result by the measuring apparatus 110. FIG. Therefore, the posture of the electrode 10 can be appropriately adjusted so as to be easily held according to the bending shape of the metal pipe material 40 to be held. Thereby, the reliability of holding|maintenance of the bent metal pipe material 40 can be improved.

The measuring device 110 may measure distances from the sensors 70A, 70B, and 70C for at least three points in the longitudinal direction of the metal pipe material 40. Thus, the bending shape of the metal pipe material 40 can be grasped|ascertained precisely when the measuring apparatus 110 measures the distance of at least three points|pieces.

The measuring device 110 may grasp, that is, measure the shape of the metal pipe material 40 with the end portion 40a positioned in the longitudinal direction of the metal pipe material 40 . By positioning the end portion 40a in this way, the measuring device 110 can easily calculate the bending shape of the metal pipe material 40 with reference to the end portion 40a.

The electrode 10 has a groove portion 81 formed in the end surface 27a and in contact with the outer peripheral surface of the metal pipe material 40, and the groove portion 81 may have a wide surface 81b that widens toward the end surface 27a. In this case, even if the electrode 10 and the metal pipe material 40 are slightly misaligned, the wide surface 81b can guide the metal pipe material 40 to the curved surface 81a.

The electrode 10 according to the present embodiment is an electrode 10 that holds a bent metal pipe material 40 and electrically heats the metal pipe material 40, and is grasped by a measuring device 110 that grasps the shape of the metal pipe material 40. Based on the obtained shape, the posture with respect to the metal pipe material 40 is adjusted.

According to the electrode 10 according to the present embodiment, it is possible to obtain the same actions and effects as those of the above-described electrical heating system 100 .

The invention is not limited to the embodiments described above.

Although the measuring part measures the distance of three points of the metal pipe material with three sensors, the distance of two points may be measured, or the distance of four or more points may be measured.

Also, the measurement unit may measure the bending shape by a method other than the distance sensor. Alternatively, the measurement unit may perform the measurement without positioning the end.

In the above-mentioned embodiment, the measuring device was illustrated as an example of the shape grasping part which grasps the shape of metal pipe material. However, the shape grasping unit may grasp the shape by estimating the shape from predetermined information, without being limited to the measurement using the sensor, as long as the method can grasp the shape. For example, the shape grasping unit may measure the load of a bending device that bends a metal pipe material in a preform device that shapes a bent metal pipe material. At this time, the shape grasping part can predict the bending degree of the metal pipe material by knowing the load. Therefore, the electrode may adjust its posture with respect to the metal pipe material based on the predicted value obtained by the prediction.

DESCRIPTION OF SYMBOLS 10... Electrode, 40... Metal pipe material, 70A, 70B, 70C... Sensor, 100... Electric heating system, 110... Measuring device (shape grasping part).

Claims (5)

An electrode that holds the bent metal pipe material and electrically heats the metal pipe material;
A shape grasping unit for grasping the shape of the metal pipe material,
The said electrode is an electric heating system of the metal pipe material which adjusts a posture with respect to the said metal pipe material based on the said shape grasped|ascertained by the said shape grasping part. 2. The electric heating system according to claim 1, wherein said shape grasping part measures distances from a sensor at least three points in the longitudinal direction of said metal pipe material. The electric heating system according to claim 1 or 2, wherein the shape grasping part grasps the shape of the metal pipe material in a state in which the ends of the metal pipe material are positioned in the longitudinal direction. The electrode has a groove formed on the end face and in contact with the outer peripheral surface of the metal pipe material,
The electric heating system according to any one of claims 1 to 3, wherein the groove portion has a wide surface whose groove width increases toward the end surface. An electrode that holds a bent metal pipe material and electrically heats the metal pipe material,
An electrode that adjusts a posture with respect to the metal pipe material based on the shape grasped by a shape grasping part that grasps the shape of the metal pipe material.

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