JP2017121643A - Method and apparatus for manufacturing torsion member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate ununiformity of a mechanical characteristic caused in a twist part of a twist member hot-processed by 3DQ.SOLUTION: A manufacturing method of a twist member of the present embodiment is a method for manufacturing the twist member from a steel pipe 62 by hot-processing the steel pipe 62 having a cross-sectional shape different from a cross-sectional circular shape, and comprises a hot-processing step and a cooling step. In the hot-processing step, the steel pipe 62 is locally heated by an induction heating coil 12 while feeding the steel pipe 62, and a twist part is formed by adding twist force to a locally-heated part of the steel pipe 62. In the cooling step, the above-mentioned twist part is cooled and hardened by cooling water injected from a cooler 18 while feeding the steel pipe 62, and a feed speed of the steel pipe 62 is adjusted in response to a twist angle per unit length of this twist part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a torsion member manufacturing method and a manufacturing apparatus for manufacturing a torsion member from a steel pipe by hot working a steel pipe.

  The present inventors are researching and developing a three-dimensional hot bending and quenching (3DQ) technique in which a steel pipe is bent into an arbitrary shape and an arbitrary portion of the steel pipe is strengthened by quenching. 3DQ is a technique suitably used for manufacturing automobile structural materials and the like. The structural material manufactured by 3DQ has the features of light weight and high strength. There is a feature that a mold is not necessary for manufacturing a structural material or the like by 3DQ.

  In the 3DQ device, the heating device and the cooling device are arranged close to each other. In the processing of a steel pipe using a 3DQ apparatus, an arbitrary part of the locally heated portion (high temperature part) of the steel pipe is generated in the steel pipe between the heating apparatus and the cooling apparatus while passing the steel pipe in the order of the heating apparatus and the cooling apparatus. Gives a bending moment in the direction. With 3DQ, any part of the steel pipe can be bent into any shape and processed into a hardened member.

  The apparatus which gives a bending moment to a steel pipe is not specifically limited. As a device for imparting a bending moment to a steel pipe, a movable roller die arranged on the downstream side of the cooling device in the steel pipe feed direction as in Patent Document 1, and a steel pipe on the downstream side in the steel pipe feed direction as in Patent Document 2 The chuck and manipulator attached to the end are exemplified, and a chuck and manipulator attached to the end of the steel pipe on the upstream side in the feed direction of the steel pipe as in Patent Document 3.

  With 3DQ, not only bending but also twisting is possible. Patent Document 1 and Patent Document 3 disclose that twist processing is possible with 3DQ. Patent Document 4 discloses a torsion member using 3DQ.

International Publication No. 2006/093006 Pamphlet International Publication No. 2010/050460 Pamphlet International Publication No. 2011/007810 Pamphlet International Publication No. 2010/084898 Pamphlet

  An object of the present invention is, as one example, to be able to eliminate non-uniformity of mechanical properties generated in a twisted portion of a twisted member hot-worked with 3DQ.

  According to an embodiment of the present invention, there is provided a method of manufacturing a torsional member, in which a steel pipe having a cross-sectional shape different from a circular cross-section is used as a basis for the torsional member in a longitudinal direction of the steel pipe relative to a heating device and a cooling device A hot working step in which the steel pipe is locally heated by the heating device while being fed and a torsional force is applied to a locally heated portion of the steel pipe to form a twisted portion; While cooling relative to the cooling device, the torsional portion is cooled and quenched by the cooling water sprayed from the cooling device, and the steel pipes are relative to each other according to the torsion angle per unit length of the torsional portion. And a cooling step for adjusting a typical feed rate.

  An apparatus for manufacturing a torsional member according to another aspect of the present invention includes a heating device that locally heats a steel pipe that has a cross-sectional shape different from a circular cross-section and that serves as a basis of the torsional member, An external force applying device that forms a twisted portion by applying a twisting force to the heated portion, a cooling device that cools and quenches the twisted portion by spraying cooling water onto the twisted portion, the heating device, and the A feeding device that sends the steel pipe relative to the heating device and the cooling device in the longitudinal direction of the steel pipe in a state where the cooling device is operating, and the steel pipe is connected to the heating device and the cooling device. When the torsion part is cooled by the cooling water sprayed from the cooling device while being relatively fed, the feeding device is controlled according to the torsion angle per unit length of the torsion part to control the steel pipe. phase And a control device for adjusting a specific feed rate.

  According to the above aspect of the present invention, it is possible to eliminate the non-uniformity of mechanical properties generated in the twisted portion of the twisted member hot-worked with 3DQ.

It is a perspective view of 3DQ apparatus. It is a sectional side view of a heating device and a cooling device. It is a front view of a cooling device. It is a perspective view which shows an example of a twist member. It is a graph showing the temperature measurement result of the corner | angular part of the steel pipe in each position where the cooling water hits when not twisting. It is a three-plane figure of the steel pipe when not twisting. It is a graph showing the temperature measurement result of the corner | angular part of the steel pipe in each position where the cooling water hits at the time of twist processing. FIG. 3 is a three-side view of a steel pipe that has been twisted under twisting conditions 1. 3 is a three-side view of a steel pipe that has been twisted under twisting condition 2. FIG. 4 is a three-side view of a steel pipe that has been twisted under twisting condition 3. FIG. FIG. 6 is a three-side view of a steel pipe that has been twisted under twisting condition 4; It is an enlarged view of the corner | angular part L of FIG. It is an enlarged view of the corner | angular part U of FIG. It is a graph showing the temperature measurement result of the corner | angular part of the steel pipe in each position where a cooling water hits at the time of changing the feed rate of the steel pipe twisted. It is a table showing an example of the table memorize | stored in a control apparatus. It is a schematic diagram which shows a mode that the position of the corner | angular part of a steel pipe moves by a twist process and a bending process.

  First, a 3DQ apparatus that is an embodiment of a manufacturing apparatus for a torsion member will be described.

  In FIG. 1, a 3DQ device 10 is shown in a perspective view. The 3DQ device 10 includes an induction heating coil 12, a high frequency power generation device 14, an external force applying device 16, a cooling device 18, a cooling water supply device 20, a feeding device 22, and a control device 24. . The 3DQ device 10 continuously performs hot working and quenching on the steel pipe 62.

  The steel pipe 62 to be processed by the 3DQ device 10 is a steel pipe having a cross-sectional shape different from a circular cross-section, for example, a cross-sectional shape such as a polygon such as a square, a rectangle, a trapezoid, or an ellipse. In this embodiment, as an example, the steel pipe 62 is formed in a horizontally long cross-sectional rectangular shape. The steel pipe 62 is fed in the longitudinal direction of the steel pipe 62 by a feeding device 22 described later. Arrow S indicates the feed direction of the steel pipe 62. Moreover, the arrow X, the arrow Y, and the arrow Z have shown the horizontal direction, the vertical direction, and the longitudinal direction of the steel pipe 62 processed with a 3DQ apparatus, respectively.

  The induction heating coil 12 is formed in a rectangular shape corresponding to the cross-sectional shape of the steel pipe 62, and is disposed so as to surround the steel pipe 62 at a predetermined distance from the outer peripheral surface of the steel pipe 62. When the induction heating coil 12 is supplied with high frequency power from the high frequency power generator 14, an induction current is locally generated in the steel pipe 62 inside the induction heating coil 12, and the steel pipe 62 is locally induced. Heat. This induction heating coil 12 is an example of a heating device. Instead of the induction heating coil 12, a heating device that can locally heat the steel pipe 62 may be used.

  The high frequency power generator 14 is connected to the induction heating coil 12 and supplies high frequency power to the induction heating coil 12. The high-frequency power generator 14 can adjust the power supplied to the induction heating coil 12 so that the steel pipe 62 can be rapidly heated to a desired temperature above the transformation point in a short time (about 2 seconds), for example.

  As an example, the external force applying device 16 includes two pairs of support rollers 32, a pair of movable roller dies 34, and a drive unit 36. The two pairs of support rollers 32 are arranged on the upstream side in the feed direction of the steel pipe 62 with respect to the induction heating coil 12, and each pair of support rollers 32 grips the steel pipe 62 from both lateral sides of the steel pipe 62. The pair of movable roller dies 34 are arranged on the downstream side in the feed direction of the steel pipe 62 with respect to the cooling device 18 to be described later, and grip the steel pipe 62 from both sides of the steel pipe 62 in the lateral direction.

  The drive unit 36 of the external force applying device 16 has a torsion function for rotating the pair of movable roller dies 34 around the axis of the steel pipe 62, and a bending function for moving the pair of movable roller dies 34 in the vertical and horizontal directions of the steel pipe 62. Have

  When the pair of movable roller dies 34 are rotated around the axis of the steel pipe 62 by the drive unit 36, a twisting force is applied to the steel pipe 62 between the support roller 32 and the movable roller die 34. Further, the driving unit 36 moves the pair of movable roller dies 34 in at least one of the longitudinal direction and the lateral direction of the steel pipe 62, thereby applying a bending force to the steel pipe 62 between the support roller 32 and the movable roller die 34. It is done.

  Such a drive unit 36 includes, for example, an XY stage that moves the pair of movable roller dies 34 in the vertical and horizontal directions of the steel pipe 62, a motor that operates the XY stage, and a pair of movable roller dies. This is realized by a drive device that combines a roll mechanism that rolls the XY stage so that 34 rotates around the axis of the steel pipe 62, and a motor that operates the roll mechanism. As the drive unit 36, a manipulator capable of rotating the pair of movable roller dies 34 around the axis of the steel pipe 62 and moving the pair of movable roller dies 34 in the vertical and horizontal directions of the steel pipe 62 may be used. .

  The cooling device 18 is disposed on the downstream side in the feed direction of the steel pipe 62 with respect to the induction heating coil 12. The cooling device 18 is formed in a rectangular ring shape corresponding to the cross-sectional shape of the steel pipe 62, and is disposed so as to surround the steel pipe 62 at a predetermined distance from the outer peripheral surface of the steel pipe 62.

  2 shows the induction heating coil 12 and the cooling device 18 in a side sectional view, and FIG. 3 shows the cooling device 18 in a front view. In FIG. 2, a locally heated portion (hot portion) of the steel pipe 62 is shown in color. FIG. 3 is a view of the cooling device 18 as viewed from the downstream side in the feed direction of the steel pipe 62 toward the upstream side.

  As shown in FIGS. 2 and 3, the cooling device 18 is formed with a plurality of injection ports 42. The plurality of injection ports 42 are provided on both sides in the vertical direction with respect to the steel pipe 62 and on both sides in the horizontal direction with respect to the steel pipe 62. In FIG. 3, some of the plurality of injection ports 42 are displayed, and the remaining illustration of the plurality of injection ports 42 is omitted. The plurality of injection ports 42 are arranged in a plurality of rows. Hereinafter, the plurality of columns are referred to as A column, B column, C column, D column, E column, F column, G column, and H column in order from the inside of the cooling device 18.

  The surface 44 through which the plurality of injection ports 42 opens faces the inside of the annular cooling device 18 and the downstream side in the feed direction of the steel pipe 62. For this reason, the cooling water is injected from the plurality of injection ports 42 toward the downstream side in the feed direction of the steel pipe 62.

  The cooling water supply device 20 shown in FIG. 1 has, for example, a water pump connected to a water supply pipe. When the water pump is activated, the cooling water is supplied to the cooling device 18 and the cooling water is jetted from the cooling device 18.

  The feeding device 22 is disposed on the side opposite to the movable roller die 34 with respect to the induction heating coil 12 and the cooling device 18 described above. The feeding device 22 includes a main body portion 52, a movable portion 54, and a driving portion 56.

  The movable portion 54 is disposed closer to the support roller 32 than the main body portion 52 and holds the steel pipe 62. The movable part 54 is movable in a direction away from the main body part 52. For example, a chuck mechanism that holds the steel pipe 62 is used for the movable portion 54. The feeding device 22 having the main body 52, the movable unit 54, and the driving unit 56 is realized by using, for example, a ball screw mechanism, an industrial robot, or the like.

  The drive unit 56 of the feeding device 22 is a power source such as a motor device, a hydraulic device, or a pneumatic device, and moves the movable unit 54 in a direction away from the main body unit 52. In the feeding device 22, the movable portion 54 moves in a direction away from the main body 52 while holding the steel pipe 62, so that the steel pipe 62 is fed in the longitudinal direction.

  In addition, in the 3DQ apparatus 10 shown in FIG. 1, the feeding device 22 that sends the steel pipe 62 is used. However, by using the feeding device that moves the induction heating coil 12 and the cooling device 18, the steel pipe 62 is induction-heated. It may be sent relative to the coil 12 and the cooling device 18.

  The control device 24 is electrically connected to the above-described high-frequency power generation device 14, the cooling water supply device 20, the drive unit 36 of the external force applying device 16, and the drive unit 56 of the feeding device 22. The control device 24 includes an electronic circuit having an arithmetic device, a storage device, and the like. The high-frequency power generation device 14, the cooling water supply device 20, the drive unit 36 of the external force applying device 16, and the feeding device 22 The drive unit 56 is controlled.

  Next, the basic operation of the 3DQ device 10 will be described.

<Feed start step>
In this 3DQ device 10, when the drive unit 56 of the feeding device 22 starts operating, the movable unit 54 holding the steel pipe 62 moves in a direction away from the main body 52, and the steel pipe 62 is fed in the longitudinal direction. . The steel pipe 62 is continuously sent until the cooling step described later is completed.

<Hot processing step>
When the feeding of the steel pipe 62 is started, the high frequency power is supplied from the high frequency power generator 14 to the induction heating coil 12. Then, an induction current is locally generated in the steel pipe 62 inside the induction heating coil 12, and the steel pipe 62 is locally induction heated.

  Further, at a predetermined timing according to product specifications, the pair of movable roller dies 34 are rotated around the axis of the steel pipe 62 by the drive unit 36 of the external force applying device 16, whereby the support roller 32 and the movable roller dies 34 are moved. In the meantime, a twisting force is applied to the locally heated portion of the steel pipe 62. And the steel pipe 62 is hot-worked and a torsion part is formed in the part heated locally of the steel pipe 62. FIG.

<Cooling step>
Further, when the feeding of the steel pipe 62 is started, the cooling water supply device 20 is activated. Then, cooling water is jetted from the cooling device 18 to the steel pipe 62, and the entire steel pipe 62 including the torsion part is cooled and quenched.

  In the 3DQ apparatus 10, a torsion member having a torsion part is manufactured from the steel pipe 62 by the above basic operation. FIG. 4 shows a perspective view of an example of a twist member 64 having a twist portion 66. An arrow T indicates the twisting direction of the steel pipe 62.

  If necessary, the pair of movable roller dies 34 are moved in at least one of the longitudinal direction and the lateral direction of the steel pipe 62 by the driving unit 56 shown in FIG. In the meantime, a bending force may be applied to the locally heated portion of the steel pipe 62. Then, bending deformation may be applied to the twisted portion 66 shown in FIG. In FIG. 1, the steel pipe 62 is shown in a bent state as a reference.

  Moreover, in the said basic operation | movement, while the induction heating coil 12 and the cooling device 18 operate | move while the steel pipe 62 passes the induction heating coil 12 and the cooling device 18 over the full length, a part of steel pipe 62 is the induction heating coil 12. In addition, the induction heating coil 12 and the cooling device 18 may operate at the timing of passing through the cooling device 18.

  Next, the examination result of the 3DQ device 10 will be described.

  The inventor performed torsion processing using the 3DQ apparatus 10 and repeated experiments and observations. As a result, when the steel pipe 62 is largely twisted, the corner portion of the steel pipe 62 may pass through the cooling device 18 in a red-hot state. In this case, the mechanical characteristics are uneven in the twisted portion of the steel pipe 62 after processing. The inventor has noticed that this may occur. Even if the temperature is not so high that the steel pipe 62 becomes red hot after passing through the cooling device 18, the quenched portion may be tempered or not quenched. For this reason, the inventor considered that it is necessary to carefully manage the temperature change at the corner of the steel pipe 62 in the twisting process.

  In order to prevent the cooling water from colliding with each other and impairing the collision pressure of the cooling water on the steel pipe 62, the injection port 42 of the cooling device 18 is preferably cooled with the outer surface of the steel pipe 62 as shown in FIG. The angle θ formed with water is close to a right angle, and the cooling water is arranged so as not to collide with each other. The inventor attached a thermocouple to the corner portion of the steel pipe 62, and measured the temperature of the corner portion of the steel pipe 62 at each position where the cooling water from the injection holes 42 in the rows A to H of FIGS.

  FIG. 5 shows the temperature measurement result of the corner portion of the steel pipe 62 at each position where the cooling water hits when not twisted, that is, the relationship between the temperature of the corner portion of the steel pipe 62 when not twisted and the feed amount. A graph is shown. A to H on the horizontal axis in FIG. 5 correspond to positions where the cooling water from the injection ports 42 in the rows A to H in FIGS. In FIG. 6, for reference, a steel pipe 62 when not twisted is shown in a three-side view.

  As shown in FIG. 5, when the twisting is not performed, the steel pipe 62 has the highest temperature at each position where the coolant from the A-row injection port 42 hits, and then the steel pipe 62 from the B-H row injection ports 42. The temperature is lowered by being cooled by the cooling water.

  On the other hand, FIG. 7 shows a graph showing the temperature measurement results of the corners of the steel pipe 62 at each position where the cooling water hits when twisted. Like the horizontal axis in FIG. 5, A to H on the horizontal axis in FIG. 7 correspond to positions where the cooling water from the injection ports 42 in the rows A to H in FIGS. In FIG. 3, the twisted portion 66 of the steel pipe 62 is indicated by an imaginary line (two-dot chain line), and the temperature measurement result of FIG. 7 is obtained at the twisted portion 66 of the steel pipe 62 indicated by the imaginary line of FIG. It is a temperature measurement result about the lower corner, that is, the corner L.

  Moreover, the temperature measurement result for every twist processing conditions 1-4 is shown by FIG. In the twisting conditions 1 to 4 in FIG. 7, the twisting angle per unit length increases in the order of the twisting conditions 1 to 4. In FIG. 8A to FIG. 8D, for reference, a steel pipe 62 that is twisted under the above-described twisting conditions 1 to 4 is shown in three views.

  The strength failure occurs in the torsional portion 66 by 3DQ is a portion where the temperature of the steel pipe 62 has increased during cooling as in the torsional processing conditions 2 to 4 in FIG. In order to confirm the situation where the temperature rise of the steel pipe 62 occurs, the inventor stopped the 3DQ machining in the twisting conditions 2 to 4 in the middle of the twisting process, and then the upper and lower sides of the injection port 42 where the temperature rise began to occur. The cooling water was individually ejected from the injection ports 42 located on the left and right. As a result, it was found that the cooling water from some of the injection ports 42 did not hit the corner portion L at the position where the temperature rise of the steel pipe 62 began to occur.

  Here, in FIG. 9, the corner portion L of FIG. 3 is shown in an enlarged view. As shown in FIG. 9, the cooling water a from the lower right end hits the corner portion L, but the cooling water a from the lower right end does not contribute much to the cooling. This is because the angle formed by the cooling water a from the side surface of the corner portion L and the lower right end is small (close to parallel), so that the cooling water cannot break through the water vapor film on the surface of the steel pipe 62. The higher the twist angle per unit length, the more the temperature rises in the upstream direction of the steel pipe 62 in the feed direction. The greater the twist angle per unit length, the greater the pressure that can break through the water vapor film on the upstream side of the steel pipe 62 in the feed direction. This is because the cooling water starts to run out.

  FIG. 10 shows the corner U of FIG. 3 in an enlarged view. When twisting by 3DQ, the corner U also has a problem in cooling if the twist angle per unit length is increased similarly to the corner L described above. This is because the cooling water b from the upper right end and the cooling water c from the upper right end collide with each other before hitting the corner portion U. As a result, the cooling water does not hit the steel pipe 62 with a predetermined pressure. This is considered to occur because the water vapor film on the surface of 62 cannot be broken.

  In addition, when the steel pipe 62 is a round pipe with a circular cross section, the manner of cooling water does not change even if the round pipe is twisted, and thus the above problem does not occur. The above-described problem occurs in a deformed pipe in which the inclination of the cross section of the steel pipe 62 is changed by twisting and the way in which the cooling water is applied is changed. The deformed pipe is a pipe whose distance from the center of the cross section of the steel pipe 62 to the steel pipe 62 varies in the circumferential direction, that is, a pipe having a cross-sectional shape different from a circular cross section such as a square pipe or an elliptic pipe. In this embodiment, the processing target of the 3DQ apparatus 10 is a steel pipe 62 having a cross-sectional shape different from a circular cross-section.

  FIG. 11 shows a graph showing the temperature measurement results of the corners of the steel pipe 62 at each position where the cooling water hits when the feed speed of the steel pipe 62 to be twisted is changed. 11 corresponds to the positions where the cooling water hits from the injection ports 42 in the rows A to H in FIGS. 2 and 3, similarly to the horizontal axes in FIGS. 5 and 7. Moreover, the temperature measurement result of FIG. 11 is a temperature measurement result about the corner | angular part L of FIG. FIG. 11 shows the temperature measurement results when the feed rate is low, medium (reference), and high.

  As can be seen from FIG. 11, if the steel pipe 62 is brought to a predetermined temperature at the inlet of the cooling device 18 (the position of the injection port 42 in the A row) and the feed speed of the steel pipe 62 is lowered, the upstream side of the steel pipe 62 in the feed direction. Thus, the cooling of the steel pipe 62 can be completed.

  For example, if the feed rate of the steel pipe 62 is lowered in the twisting condition 4 of FIG. 7, as shown in FIG. 11, as shown in FIG. If the cooling water hits part L). Accordingly, if the steel pipe 62 is fed at the low feed rate in FIG. 11 under the twisting condition 4 in FIG. 7, the cooling can be completed at a position where the cooling water of the jet nozzle 42 in the E row hits the steel pipe 62, and the torsion part after 3DQ machining The occurrence of non-uniform mechanical characteristics in 66 can be suppressed.

  Note that if the feed rate is lowered over the entire length of the steel pipe 62, the machining efficiency is hindered. Therefore, the feed rate of the steel pipe 62 is adjusted in accordance with the change of the twist angle (twisting condition) per unit length of the twisted portion 66. Adjust it.

  However, when the feed rate of the steel pipe 62 is decreased, the amount of heat input per unit length of the steel pipe 62 increases, and the temperature of the locally heated portion of the steel pipe 62 between the induction heating coil 12 and the cooling device 18 is increased. Therefore, the high-frequency power generator 14 is controlled according to the feed rate so that the temperature of the locally heated portion of the steel pipe 62 becomes a predetermined temperature at the inlet of the cooling device 18 regardless of the feed rate. You may do it.

  Further, when bending the steel pipe 62 at the same time as the twisting process, the torsion part 66 is also deformed by the curvature radius (bending condition) of the torsion part 66 to which the bending deformation is applied, as in the case of the twisting process. It is assumed that non-uniform mechanical properties occur. For this reason, it is desirable to adjust the feed rate also by the radius of curvature of the torsion part 66 to which bending deformation has been applied.

  Next, functions added to the 3DQ device 10 will be described based on the above examination results.

In the 3DQ device 10 of the present embodiment, the following functions are added to the control device 24.
<Function 1>
Control function for adjusting the feed rate of the steel pipe 62 <Function 2>
Control function of output (heating condition) of induction heating coil 12 according to feed rate of steel pipe 62 <Function 3>
The feed rate adjustment function of the steel pipe 62 according to the twist angle (twisting condition) per unit length of the twisted portion 66

  In order to realize the feed rate adjustment function of the steel pipe 62, it is desirable that the control device 24 stores a table for deriving the feed rate from the twisting conditions. In this embodiment, the feed rate and heating conditions of the steel pipe 62 are controlled according to the twisting conditions. Specifically, the following controls 1 and 2 are performed.

<Control 1>
Processing conditions in which the feed rate and heating conditions are set in accordance with the twisting conditions that change from moment to moment are input to the control device 24. Then, the control device 24 controls the drive unit 56 of the feeding device 22, the high frequency power generation device 14, and the drive unit 36 of the external force applying device 16 based on the input machining conditions.
<Control 2>
A table in which the feed speed upper limit value is set according to the twisting conditions is stored in the control device 24. The control device 24 derives the feed speed upper limit value from the table according to the change of the twisting process condition, and derives the heating condition according to the feed speed upper limit value from the above-described machining conditions. And the control apparatus 24 controls the drive part 56 of the feeder 22 and the high frequency electric power generator 14 (output of the induction heating coil 12) based on the above derivation result.

  Note that when the steel pipe 62 is bent at the same time as the twisting, the situation where the cooling water hits the steel pipe 62 changes. Therefore, when the bending process is applied to the steel pipe 62 simultaneously with the twisting process, the above-described function 3 is as follows.

<Other examples of function 3>
The feed rate adjustment function of the steel pipe 62 according to the twist angle and the curvature radius (twisting condition and bending condition) per unit length of the torsion part 66

  When bending the steel pipe 62 at the same time as twisting, it is desirable that the control device 24 stores a table for deriving the feed rate from the twisting conditions and the bending conditions. When bending the steel pipe 62 at the same time as twisting, the above-described controls 1 and 2 are as follows.

<Other examples of control 1>
Processing conditions in which the feed speed and heating conditions are set in accordance with the twisting and bending conditions that change from moment to moment are input to the control device 24. Then, the control device 24 controls the drive unit 56 of the feeding device 22, the high frequency power generation device 14, and the drive unit 36 of the external force applying device 16 based on the input machining conditions.
<Other examples of control 2>
A table in which the feed speed upper limit value is set in accordance with the torsion processing conditions and the bending processing conditions is stored in the control device 24. The control device 24 derives the feed speed upper limit value from the table according to changes in the twisting condition and the bending condition, and derives the heating condition according to the feed speed upper limit value from the above-described machining conditions. And the control apparatus 24 controls the drive part 56 and the high frequency electric power generator 14 of the feeder 22 based on the above derivation result.

  Next, the manufacturing method of the twist member by the 3DQ apparatus 10 to which the above function is added will be described.

  In the manufacturing method of the torsional member by the 3DQ device 10 to which the above function is added, the feed start step, the hot working step, and the cooling step are executed as in the basic operation of the 3DQ device 10 described above.

  However, in the cooling step, the feed rate of the steel pipe 62 is adjusted as described below. As an example, the feed rate of the steel pipe 62 is adjusted according to the twist angle and the radius of curvature of the twisted portion 66 per unit length.

  The control device 24 controls the feed rate of the steel pipe 62 from the table based on the twisting condition including the twisting direction and the twisting angle per unit length, and the bending condition including the bending direction and the radius of curvature. To derive.

  In the table, the torsional processing conditions include “R-0”, “R-1”, “R-2”, “R-3”, “L-0”, “L-” by combining the twisting direction and the twisting angle. 1 ”,“ L-2 ”, and“ L-3 ”. Regarding the twisting direction, “R” represents clockwise rotation, and “L” represents counterclockwise rotation. Further, the twist angle per unit is represented by “0” when not twisted, and when twisted, it is represented by “1”, “2”, “3” in ascending order of the twist angle per unit. Is done.

  Further, in the table, the bending process conditions are “0-0”, “0-1”, “0-2”, “0-3”, “1-0”, “1-0” by combining the bending direction and the radius of curvature. 1-1 ”,...“ 11-0 ”,“ 11-2 ”,“ 11-3 ”. The bending direction is divided into 12 directions from the downstream side in the feed direction of the steel pipe 62 toward the upstream side. That is, like the clock, the top is represented by “0”, the right is “3”, the bottom is “6”, and the left is “9”. The curvature radius is represented by “0” when not bending, and by “1”, “2”, and “3” in descending order of curvature radius when bending.

  Further, in the table, the feed speed of the steel pipe 62 is “High”, which is the same speed as that when neither twisting nor bending is performed, “Mid” which is slower than “High”, and “Low” which is slower than “Mid”. It is classified into three stages.

  FIG. 12 shows a table representing an example of the table 26 stored in the control device 24. The table 26 shown in FIG. 12 shows a case of bending in the 1 o'clock direction by clockwise twisting. The table 26 shown in FIG. 12 is an example, and the control device 24 may store a table including other twisting directions and bending directions.

  Depending on the cross-sectional shape of the steel pipe 62 that is the object to be processed, it is possible to integrate a plurality of tables. For example, when the steel pipe 62 having a rectangular cross section is targeted, the tables 2 to 8 exemplified below can be integrated into the table 1 when bending in the direction of 1 o'clock by clockwise twisting. It is.

Table 2: Table when bending in the 5 o'clock direction by clockwise twisting Table 3: Table when bending in the 7 o'clock direction by clockwise twisting Table 4: 11 by clockwise twisting Table when bending in the hour direction Table 5: Table when bending in the 1 o'clock direction with counterclockwise twisting Table 6: Table when bending in the 5 o'clock direction with counterclockwise twisting Table 7: Table when bending in the 7 o'clock direction by counterclockwise twisting Table 8: Table when bending in the 11 o'clock direction by counterclockwise twisting

  As described above, the control device 24 stores the table 26 that represents the relationship between the twist angle and the curvature radius per unit length of the torsion portion 66 and the feed speed of the steel pipe 62. Then, the control device 24 derives the feed speed of the steel pipe 62 from the table 26 based on the twist angle per unit length and the radius of curvature of the torsion portion 66, and controls the feed device 22 so as to be the derived feed speed. To do. That is, the control device 24 decreases the feed speed of the steel pipe 62 as the twist angle per unit length of the twisted portion 66 is larger and as the curvature radius is smaller.

  Here, FIG. 13 is a schematic diagram showing how the position of the corner of the steel pipe 62 is moved by twisting and bending. In FIG. 13, the thin line rectangle indicates the position of the cross section of the steel pipe 62 when neither twisting nor bending is performed, and the two-dot chain line rectangle indicates the position of the cross section of the steel pipe 62 when twisting. ing. Moreover, the rectangle of a thick line has shown the position of the cross section of the steel pipe 62 at the time of twisting and bending.

The change in the position of the corner of the steel pipe 62 where the cooling unevenness of the steel pipe 62 occurs is the sum of the change in position due to the twisting process and the change in position due to the bending process. By twisting with a twisting angle φ, the corner of the steel pipe 62 moves h1 in the vertical direction. h1 is calculated by the following equation (1). In the following formula (1), W is the width of the steel pipe 62.
h1 = (W / 2) · sinφ (1)

Furthermore, the corner | angular part of the steel pipe 62 moves by bending. As shown in FIG. 13, when bending to the size of l in the direction of 4 o'clock, the corner portion of the steel pipe 62 moves h2 in the vertical direction by bending. h2 is calculated by the following equation (2). The amount of movement h of the corner of the steel pipe 62 in the longitudinal direction by twisting and bending is calculated by the following equation (3).
h2 = lsinφ (2)
h = h1 + h2 (3)

  As shown in FIG. 3, in the 3DQ device 10 of the present embodiment, the cooling water is injected into the steel pipe 62 so that the cooling water from the vertical direction and the horizontal direction do not excessively interfere with each other. Regarding how much the corner of the steel pipe 62 moves in the vertical direction, the cooling water from the lateral direction does not hit the corner of the steel pipe 62. For example, the structure of the cooling device 18, for example, the position of each injection port 42, Since it differs depending on the distance between the adjacent injection ports 42, it is desirable to know in advance.

  For example, the steel pipe on the cross section at the location (the location where the cooling water from the injection nozzle 42 in the H row in FIG. 2 hits) of the location where the cooling water collides with the steel tube 62 is located on the most downstream side in the feed direction of the steel tube 62. The direction of the corner of 62 is perpendicular to the injection direction of the coolant injected into the corner as viewed in the feed direction of the steel pipe 62 compared to the position of the corner when the steel pipe 62 is not hot-worked (in this case) , In the vertical direction), when it moves more than a specified amount (for example, 10 mm), the corner of the steel pipe 62 may begin to run out of contact with the cooling water.

  In this case, it is desirable to adjust the feed rate so that cooling of the torsion part is completed at a position where water hits the steel pipe 62 from the injection port 42 located on the most downstream side in the feed direction of the steel pipe 62. That is, it is desirable to lower the feed speed of the steel pipe 62 compared to the feed speed when the steel pipe 62 is not hot-worked, for example, to change to “Mid” or “Low” in the table shown in FIG. The relationship between the horizontal movement of the corner of the steel pipe 62 and the cooling water sprayed from the vertical direction is the same.

  With the method described above, it is possible to create a table of machining conditions and feed rates in advance without actually performing 3DQ machining. However, it is desirable to further adjust the table with the actual machine before mass production. The reason is as follows.

<Reason 1>
The collision angle with the steel pipe 62 differs between the cooling water on the upstream side of the facility and the cooling water on the downstream side. That is, when the cooling water collides with the steel pipe 62, the angle formed by the cooling water injected from the steel pipe 62 and the injection port 42 on the downstream side becomes smaller. For this reason, the cooling capacity is different between the cooling water on the upstream side and the cooling water on the downstream side, and the cooling capacity on the upstream side becomes higher, so there is a possibility that deceleration can be alleviated.
<Reason 2>
It is not known how the cooling water hitting the corner of the steel pipe 62 rebounds and interferes with other cooling water.
<Reason 3>
The cooling device 18 is arranged in accordance with the outer shape of the steel pipe 62. However, when the cross-sectional shape of the steel pipe 62 is a curved shape or an elliptical shape, the vertical and horizontal deviations and changes in the cooling capacity can be easily understood like a square tube. Hateful.
<Reason 4>
When the cooling water hits the corner of the steel pipe 62 halfway, it may not be sufficiently cooled.

  The table is adjusted by actually performing 3DQ processing and analyzing the steel pipe 62 to check whether cooling is insufficient. Specifically, the hardness (for example, Vickers altitude Hv420 or more) and the surface residual stress (for example, tensile stress of 80 MPa or less as measured by the X-ray diffraction method) of the steel pipe 62 after processing are within a predetermined range even when variation is taken into consideration. If so, it is determined that it has been sufficiently cooled.

  In the case of the 3DQ device 10 using the movable roller die 34 as in this embodiment, the control device 24 may output the feed speed from the table based on the movement of the movable roller die 34.

  However, when a bending moment is applied by a manipulator via a chuck attached to the end of the steel pipe 62, it is difficult to derive processing conditions from the movement of the end of the steel pipe 62. In this case, the twisting condition and the bending condition may be derived from the twisting amount and the bending amount along the longitudinal direction of the steel pipe 62 based on the target product shape. This method can also be applied when the movable roller die 34 is used.

  In the 3DQ device 10, when bending is not performed, the relationship between the radius of curvature and the feed rate of the steel pipe 62 may be deleted from the table 26 described above. Then, the control device 24 derives the feed speed of the steel pipe 62 from the table 26 based on the twist angle per unit length of the torsion part 66, and controls the feed device 22 so as to obtain the derived feed speed. good. That is, the control device 24 may decrease the feed speed of the steel pipe 62 as the twist angle per unit length of the twist portion 66 is larger.

  Further, when a feeding device that moves the induction heating coil 12 and the cooling device 18 is used to send the steel pipe 62 relative to the induction heating coil 12 and the cooling device 18, the table 26 has a relative relationship between the steel pipe 62 and the steel heating device 62. The moving speed of the induction heating coil 12 and the cooling device 18 may be included as a typical feed rate.

  Next, the operation and effect of this embodiment will be described.

  As described in detail above, according to the present embodiment, the torsional portion 66 is cooled by the cooling water sprayed from the cooling device 18 while the steel pipe 62 is being sent relative to the induction heating coil 12 and the cooling device 18. In this case, the relative feed speed of the steel pipe 62 is adjusted in accordance with the twist angle per unit length of the twist portion 66. Thereby, since the cooling nonuniformity of the corner | angular part of the steel pipe 62 can be suppressed, the nonuniformity of the mechanical characteristic which arises in the torsion part 66 of the torsion member 64 hot-worked by 3DQ can be eliminated.

  Further, when a torsional force and a bending force are applied to the steel pipe 62 and a bending deformation is applied to the torsion part 66, the relative feed of the steel pipe 62 according to the torsion angle and the curvature radius of the torsion part 66 per unit length. The speed is adjusted. As a result, the steel pipe 62 can be relatively fed at an appropriate feed rate in consideration of bending deformation, so that even when bending deformation is applied to the torsion portion 66, uneven cooling of the corners of the steel pipe 62 according to the bending deformation. Can be suppressed.

  Further, for example, on the cross section at the location (the location where the coolant from the injection nozzle 42 in the H row in FIG. 2 hits) located on the most downstream side in the feed direction of the steel tube 62 among the locations where the coolant collides with the steel tube 62. The direction of the corner of the steel pipe 62 is perpendicular to the injection direction of the cooling water injected into the corner as viewed in the feed direction of the steel pipe 62 compared to the position of the corner when the steel pipe 62 is not hot-worked ( In this case, in the case where the steel pipe 62 is moved in the vertical direction) by a specified amount (for example, 10 mm) or more, the feed speed of the steel pipe 62 is reduced compared to the feed speed when the steel pipe 62 is not hot worked. The same applies to the lateral movement of the corners of the steel pipe 62 and the cooling water jetted from the vertical direction. As a result, it is possible to avoid cooling with the cooling water before the corner portion of the steel pipe 62 is sufficiently cooled, so that the uneven cooling of the corner portion of the steel pipe 62 can be more effectively suppressed. .

  In addition, the control device 24 stores a table 26 that represents the relationship between the twist angle per unit length of the twisted portion 66 and the relative feed speed of the steel pipe 62. Then, the control device 24 derives the relative feed speed of the steel pipe 62 from the table 26 based on the twist angle per unit length of the torsion portion 66, and controls the feed device 22 so as to obtain the derived feed speed. To do. Therefore, since the relative feed speed of the steel pipe 62 is adjusted based on the table 26, the uneven cooling at the corners of the steel pipe 62 can be stably suppressed.

  Further, when a torsional force and a bending force are applied to the steel pipe 62 and bending deformation is applied to the torsion part 66, the table 26 has a torsion angle and a radius of curvature per unit length of the torsion part 66 and the relative relationship between the steel pipe 62. The relationship with the feed rate is included. Therefore, even when bending deformation is applied to the twisted portion 66, uneven cooling at the corners of the steel pipe 62 can be stably suppressed according to the bending deformation.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and other various modifications can be made without departing from the spirit of the present invention. It is.

10 3DQ device (an example of a twisted member manufacturing device)
12 Induction heating coil (example of heating device)
14 High-frequency power generator 16 External force applying device 18 Cooling device 20 Cooling water supply device 22 Feeding device 24 Control device 26 Table 42 Injection port 62 Steel pipe 64 Torsion member 66 Torsion part

Claims (8)

The steel pipe is locally heated by the heating device while feeding a steel pipe having a cross-sectional shape different from a circular cross-section relative to the heating device and the cooling device in the longitudinal direction of the steel pipe. And a hot working step of forming a twisted portion by applying a twisting force to a locally heated portion of the steel pipe, and
While the steel pipe is fed relative to the heating device and the cooling device, the twisted portion is cooled and quenched by the cooling water sprayed from the cooling device, and the twist angle per unit length of the twisted portion A cooling step for adjusting a relative feed rate of the steel pipe according to:
A method for manufacturing a torsion member. In the hot working step, torsional force and bending force are applied to the steel pipe to add bending deformation to the torsion part,
In the cooling step, a relative feed rate of the steel pipe is adjusted according to a twist angle and a radius of curvature per unit length of the twist portion.
The manufacturing method of the twist member of Claim 1. In the cooling step, the position of the corner portion of the steel pipe is hot-worked on the cross section at the position located most downstream in the feed direction of the steel pipe among the places where the cooling water collides with the steel pipe. Compared to the position of the corner when not moving, when the steel pipe moves more than a specified amount in a direction perpendicular to the injection direction of the cooling water injected into the corner as viewed in the feed direction of the steel pipe, Reducing the typical feed rate compared to the relative feed rate when the steel pipe is not hot worked,
The manufacturing method of the torsion member of Claim 1 or Claim 2. A heating device that locally heats a steel pipe that has a cross-sectional shape different from a circular cross-section and is the basis of a torsion member;
An external force applying device that forms a twisted portion by applying a twisting force to a locally heated portion of the steel pipe by the heating device;
A cooling device that cools and quenches the twisted portion by spraying cooling water onto the twisted portion;
A feeding device that sends the steel pipe relative to the heating device and the cooling device in the longitudinal direction of the steel pipe in a state where the heating device and the cooling device are operating
A twist angle per unit length of the torsional portion when the torsional portion is cooled by the cooling water sprayed from the cooling device while the steel pipe is sent relative to the heating device and the cooling device. A control device for controlling the feed device according to the control and adjusting the relative feed rate of the steel pipe;
An apparatus for manufacturing a torsion member. The control device stores a table representing a relationship between a twist angle per unit length of the torsion part and a relative feed rate of the steel pipe,
The control device derives a relative feed rate of the steel pipe from the table based on a twist angle per unit length of the torsion part, and controls the feed device to be the derived feed rate.
The manufacturing apparatus of the torsion member of Claim 4. The external force applying device applies a torsional force and a bending force to the steel pipe to apply a bending deformation to the torsion part,
The control device controls the feed device according to a twist angle and a radius of curvature per unit length of the torsion part to adjust a relative feed speed of the steel pipe.
The manufacturing apparatus of the torsion member of Claim 4. The control device stores a table representing a relationship between a twist angle and a curvature radius per unit length of the torsion part and a relative feed rate of the steel pipe,
The control device derives a relative feed rate of the steel pipe from the table based on a twist angle and a curvature radius per unit length of the torsion portion, and the feed device is set so as to obtain the derived feed rate. Control,
The manufacturing apparatus of the torsion member of Claim 6. The control device is configured to hot-work the steel pipe on a cross section at a position located on the most downstream side in the feed direction of the steel pipe among the places where the cooling water collides with the steel pipe. Compared to the position of the corner when not moving, when the steel pipe moves more than a specified amount in a direction perpendicular to the injection direction of the cooling water injected into the corner as viewed in the feed direction of the steel pipe, The feed device is controlled such that the typical feed rate is lower than the feed rate when the steel pipe is not hot-worked,
The manufacturing apparatus of the torsion member as described in any one of Claims 4-7.