JP6032607B2 - Steel pipe hot working equipment - Google Patents

Description

  In the present invention, the steel pipe is locally heated by the heating means while moving in the longitudinal direction, and a bending moment is applied by a bending device to the portion where the temperature has been increased by the heating, and then the steel pipe is cooled by a cooling means and then subjected to a predetermined bending. The present invention relates to a hot processing apparatus for a steel pipe for obtaining a steel pipe having a shape.

  A feed device that feeds a long metal material having a closed cross section in the longitudinal direction, a support device that supports the metal material so as to be movable in the feed direction, a high-frequency heating device that heats the metal material that has passed through the support device, and high-frequency heating An apparatus for manufacturing a bent product, comprising: a cooling device that cools a metal material that has passed through the device; and a gripping means that grips a tip of the metal material in the feed direction and applies a bending moment to a portion heated by a high-frequency heating device. This is known from US Pat.

WO2010 / 050460

  By the way, the invention described in the above-mentioned patent document 1 applies bending moment to a metal material with a gripping device while extruding a long metal material in a longitudinal direction with a feeding device, Since it is necessary to coordinately control the feed rate of the material and the movement trajectory of the gripping device to apply the bending moment, the problem is that it is difficult to increase the machining accuracy of the product because the coordinated control becomes extremely complicated. there were. In addition, since there is a restriction on the amount of feeding of the metal material by the feeding device, there is a problem that the length of the product is restricted by the feeding amount of the feeding device even if there is a margin in the capacity on the gripping means side.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to increase the processing accuracy of a steel pipe by a hot processing apparatus and to enable processing of a long steel pipe.

In order to achieve the above object, according to the invention described in claim 1, a steel pipe guide means for guiding a straight steel pipe movably in a longitudinal direction, and disposed downstream of the steel pipe guide means, the A heating means for heating the steel pipe; a cooling means arranged downstream of the heating means for cooling the steel pipe; a gripping means for gripping a gripping point of the steel pipe downstream of the cooling means; and the gripping means A bending device that moves in a three-dimensional space; and a position detection means that optically or magnetically detects a position of a reference point formed on the steel pipe, wherein the steel pipe is formed by roll forming, and the reference point which is composed of a hole formed during roll forming of the self-piercing nut or the steel pipe which is fixed at the time of roll forming of the steel pipe, the gripping means該把the gripping point of the steel pipe When the position detecting means detects that the reference point has reached a predetermined position, the bending device moves the gripping means and applies a bending moment to the steel pipe. Thus, there is proposed a hot-working apparatus for steel pipes, wherein the steel pipe is bent at a machining position in the vicinity of the heating means .

According to a second aspect of the present invention, in addition to the structure of the first aspect, the hot-working device for a steel pipe is characterized in that the self-piercing nut or the hole is fastened to a vehicle body part of an automobile. Proposed.

According to a third aspect of the present invention, in addition to the structure of the first or second aspect , the portion to be bent of the steel pipe is a portion that is coupled to a body part of an automobile. A steel pipe hot working apparatus is proposed.

According to the invention described in claim 4 , in addition to the structure of any one of claims 1 to 3 , the steel pipe is a front side frame of an automobile. A processing device is proposed.

  The guide roller 12 of the embodiment corresponds to the steel pipe guide means of the present invention, the high-frequency heating coil 13 of the embodiment corresponds to the heating means of the present invention, and the cooling device 14 of the embodiment corresponds to the cooling of the present invention. The chuck 17 of the embodiment corresponds to the gripping means of the present invention, and the stay 30 and the front subframe 33 of the embodiment correspond to the vehicle body parts of the present invention.

According to the configuration of the first aspect, when the gripping means grips the gripping point of the steel pipe and pulls it out from the steel pipe guide means, and moves along the predetermined movement trajectory in the three-dimensional space, the steel pipe heated by the heating means is processed. A product having a predetermined shape can be obtained by being bent by receiving a bending moment at a point and then being cooled by the cooling means. At that time, when the position detecting means optically or magnetically detects that the reference point formed on the steel pipe has reached a predetermined position, the bending device moves the gripping means to apply a bending moment to the steel pipe. Is bent at the processing position in the vicinity of the heating means, so that the accuracy of bending of the steel pipe can be improved and a highly accurate product can be obtained.

  Moreover, the steel pipe guide means does not need to push out the steel pipe, and the gripping means that moves with the bending device has a function of pulling out the steel pipe, so that not only the steel pipe feeding means is unnecessary, but also the steel pipe feeding means and the bending device need to be coordinatedly controlled. This eliminates the problem and improves the processing accuracy of the product. In addition, the length of the product is not limited by the ability of the steel pipe feeding means, and a long product corresponding to the amount of steel pipe drawn by the gripping means can be processed.

  In addition, in the conventional case where the gripping means supports the gripping point of the steel pipe so as to be relatively movable, only the bending moment corresponding to the distance between the processing point and the gripping point can be applied to the processing point of the steel pipe. By gripping the gripping means so that it cannot move relative to the gripping means, it becomes possible to apply a further bending moment by twisting the gripping point of the steel pipe with the gripping means, and increase the degree of freedom of the bending moment applied to the processing point. be able to.

Moreover, the steel pipe is formed by roll forming, and the reference point is composed of a self-piercing nut fixed at the time of roll forming of the steel pipe or a hole formed at the time of roll forming of the steel pipe. Not only can nuts or holes be provided at the same time, but it is not necessary to provide special reference points by using self-piercing nuts or holes as reference points.

According to the second aspect of the present invention, since the self-piercing nut or hole is a reference point for bending, the positional accuracy is high, and the self-piercing nut or hole is fastened to the body part of the automobile. The coupling accuracy of is improved.

According to the third aspect of the present invention, since the portion to be bent of the steel pipe is a portion to be connected to the car body part of the automobile, the steel pipe and the car body part can be accurately combined by bending the steel pipe with high accuracy. improves.

According to the fourth aspect of the present invention, since the steel pipe is a front side frame of an automobile, the accuracy of the front side frame can be increased and the displacement of the mounting position of the engine or the like can be reduced.

The figure which shows the whole structure of the hot three-dimensional bending apparatus of a steel pipe. FIG. 2 is a two-direction enlarged arrow view of FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. The figure which shows the manufacturing process of a steel pipe. The side view of the front side frame and front sub-frame of a motor vehicle. Action explanatory drawing corresponding to FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a hot working apparatus 11 that heats a steel pipe W that is a workpiece according to the present embodiment and bends it into a predetermined shape includes a plurality of guide rollers 12 that guide the straight steel pipe W in the longitudinal direction. ..., a high-frequency heating coil 13 as a heating means provided downstream of the guide rollers 12, a cooling device 14 as a cooling means provided downstream of the high-frequency heating coil 13, and a downstream side of the cooling device 14 And a bending device 15 made of a robot.

  The bending device 15 includes a chuck 17 as a gripping means for gripping the steel pipe W at the distal ends of a plurality of arms 16 connected to bendable by joints. The chuck 17 has a gripping surface that is in close contact with the outer surface of the gripping point 18 of the steel pipe W. When the gripping point 18 is gripped by the chuck 17, the chuck 17 and the gripping point 18 are integrated so as not to move relative to each other. Therefore, by moving the position of the chuck 17 in the longitudinal direction of the steel pipe W, the steel pipe W can be pulled out in the longitudinal direction along the guide rollers 12 without requiring a special feeding device. Further, a bending moment can be generated in the steel pipe W by moving the position of the chuck 17 in a direction perpendicular to the longitudinal direction of the steel pipe W or by twisting at the position of the chuck 17.

  As shown in FIG. 2, the steel pipe W is a linear member having a substantially rectangular cross section in the longitudinal direction, and ridge lines 19 at the four corners are guided by guide rollers 12. The four guide rollers 12 positioned at the downstream end in the moving direction of the steel pipe W serve as bending fulcrums, and the high-frequency heating coil 13 is disposed as close as possible to the downstream side of the guide rollers 12 serving as the bending fulcrum. Is done. The reason is that when the chuck 17 of the bending device 15 is moved to apply a bending moment to the steel pipe W, the largest bending moment acts on the steel pipe W at the position of the guide roller 12 as the bending fulcrum. By placing the high-frequency heating coil 13 at the position where the moment is maximized and heating the steel pipe W, the steel pipe W can be accurately bent while minimizing the bending load applied to the steel pipe W by the bending device 15. Because.

  The high-frequency heating coil 13 is composed of a two-turn coil having a first turn portion 13a and a second turn portion 13b connected in series, and a substantially constant gap is formed between the inner periphery and the outer periphery of the steel pipe W. The Two cables 20, 20 for supplying electric power to the inlet of the first turn portion 13 a and the outlet of the second turn portion 13 b of the high-frequency heating coil 13 are connected.

  The cooling device 14 includes an annular cooling water tank 21 surrounding the outer periphery of the steel pipe W, four cooling water supply pipes 22 connected to the outer peripheral surface of the cooling water tank 21, and an inner peripheral surface of the cooling water tank 21. A number of formed cooling water ejection holes 21a are provided.

  As shown in FIG. 3, four grooves 23 extending in the longitudinal direction are formed on four surfaces of the steel pipe W having a substantially square cross section having four ridge lines 19, and the grooves 23 on one surface thereof. Two well-known self piercing nuts (Self Piercing and Clinching Nut) 24, 24 are provided at a position sandwiching the pin.

  FIG. 4 shows a manufacturing process of the steel pipe W. First, a steel plate is pressed to manufacture a corrugated cross-section blank 25, and self-piercing nuts 24 and 24 are driven into predetermined positions of the blank 25. When the self-piercing nuts 24, 24 are driven into the blank 25, holes 26, 26 (see FIG. 3) are formed in the blank 25 by the self-piercing nuts 24, 24 themselves, and the self-piercing nuts 24, 24 are caulked to the blank 25. It is fixed by. Subsequently, the blank 25 to which the self-piercing nuts 24 and 24 are fixed is bent, and both end portions are butted and welded to manufacture a steel pipe W having a square cross section.

  Returning to FIG. 1, on the downstream side of the cooling device 14, position detection means 27 for detecting the positions of the self-piercing nuts 24, 24 provided on the steel pipe W is provided. The position detection means 27 optically or magnetically detects a reference point 28 constituted by the holes 26 and 26 of the steel pipe W formed by the self-piercing nuts 24 and 24 and the self-piercing nuts 24 and 24 themselves.

  As shown in FIGS. 5 and 6, the steel pipe W of the present embodiment is used as front side frames 29 and 29 of an automobile. A pair of left and right front side frames 29, 29 that are curved in an S shape are arranged in the longitudinal direction of the vehicle body, and a front portion at a high position constitutes linear portions 29a, 29a that extend linearly, and the rear portions of the straight portions 29a, 29a. Curved portions 29b and 29b extend downward and rearward from the ends. The curved portion 29b of the front side frame 29 is bent by the hot working apparatus 11 of the present embodiment.

  The self-piercing nuts 24, 24 are provided on the upper surface of the straight portion 29a, and the stay 30 is fixed to the straight portion 29a using the self-piercing nuts 24, 24. A front front subframe support bracket 31 and a rear front subframe support bracket 32 are welded to the lower surface of the straight portion 29a and the lower surface of the curved portion 29b, respectively.

  The front portion and the rear portion of the front subframe 33 formed in a frame shape are elastically supported by the front front subframe support bracket 31 and the rear front subframe support bracket 32 via mount members 34 and 35, respectively. A front engine support bracket 37 and a rear engine support bracket 38 are provided on a side surface and a rear surface of the engine 36, and the front engine support bracket 37 and the rear engine support bracket 38 are mounted on the stay 30 and the front subframe 33, respectively. It is elastically supported via members 39 and 40.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  The gripping point 18 of the steel pipe W drawn from the guide rollers 12 is gripped by the chuck 17 of the bending device 15 at a position that has passed through the high-frequency heating coil 13 and the cooling device 14. The front and rear direction of the steel pipe W is set so that the front end side (straight line portion 29a side) of the front side frame 29 as a product is the front side and the rear end side (curved portion 29b side) is the rear side.

  When a high-frequency current is supplied to the high-frequency heating coil 13 via the cables 20 and 20, an eddy current is generated inside the steel pipe W by a magnetic field formed around the high-frequency heating coil 13, and the steel pipe W is transformed into A3 by Joule heat. Heated to a temperature above the point. The temperature of the steel pipe W becomes the highest in the vicinity of the processing point 41 (see FIG. 1) immediately after passing through the high-frequency heating coil 13, and the steel pipe W that has received the bending moment at the processing point 41 is bent into a desired shape. The The steel pipe W bent at the processing point 41 is immediately supplied to the cooling device 14 and is quenched and quenched by the cooling water ejected from the cooling water ejection holes 21a of the cooling water tank 21. Even if it receives a moment, it will not be permanently deformed.

  The timing for applying a bending moment to the steel pipe W by the chuck 17 of the bending device 15 is the position detection means 27 (see FIG. 1) based on the positions of the holes 26 and 26 of the self-piercing nuts 24 and 24, which are reference points 28 provided on the steel pipe W. It is decided by detecting with. That is, the position detection means that the distance from the processing point 41 of the reference point 28 has reached the preset distance L, that is, the distance L (see FIG. 5) from the reference point 28 to the boundary between the straight line portion 29a and the curved portion 29b. 27, the bending portion is applied to the steel pipe W by the chuck 17 so that the rear portion (the portion corresponding to the bending portion 29b) can be accurately bent from the boundary. The distance L increases sequentially as the bending of the steel pipe W proceeds.

  Although the position of the machining point 41 changes according to the drawing speed of the steel pipe W, the position of the machining point 41 is substantially set by setting the movement locus of the chuck 17 of the bending device 15 so that the drawing speed is substantially constant. Can be assumed to be constant. The steel pipe W between the processing point 41 and the cooling device 14 is also in a high temperature state, but the bending moment applied to the steel pipe W by the chuck 17 of the bending device 15 increases as the distance from the chuck 17 increases. The once bent steel pipe W is not bent again after passing through the processing point 41.

  Thus, by moving the chuck 17 of the bending device 15 along a predetermined movement trajectory, the steel pipe W is continuously bent and quenched, and is bent into a predetermined shape. The side frame 29 can be obtained. The obtained front side frame 29 is cut off from the unprocessed steel pipe W on the upstream side, and then unnecessary portions at both ends are cut off.

  As described above, when the position detecting means 27 detects that the reference point 28 formed on the steel pipe W has reached the predetermined position, the bending device 15 moves the chuck 17 to apply a bending moment to the steel pipe W, and thereby the steel pipe. Since W is bent at the processing point 41 in the vicinity of the high-frequency heating coil 13, the accuracy of bending of the steel pipe W can be improved and a highly accurate product can be obtained.

  Further, the conventional steel pipe W feeding device is abolished and only the guide roller 12... For guiding the steel pipe W in a movable manner is provided, and the bending device 15 has a function of pulling out the steel pipe W, so that the feeding device and the bending device are coordinated. This eliminates the need for control and improves the processing accuracy of the product. Also, the length of the product is no longer limited by the ability of the feeding device, and a long product corresponding to the amount of steel pipe W drawn by the bending device 15 is eliminated. Can be processed.

  When the chuck 17 of the bending device 15 supports the gripping point 18 of the steel pipe W so as to be relatively rotatable, only a bending moment corresponding to the distance from the gripping point 18 can be applied to the steel pipe W. Is gripped so as not to move relative to the chuck 17, so that a further bending moment can be applied by twisting the gripping point 18 of the steel pipe W with the chuck 17, and the bending moment applied to the processing point 41 can be freely set. The degree can be increased.

  Further, since the steel pipe W is formed by roll forming, and the reference point 28 is composed of self-piercing nuts 24, 24 that are fixed during roll forming of the steel pipe, the self-piercing nut 24, 24 can be fixed at the same time, and it is not necessary to provide a special reference point by using the holes 26 and 26 of the self-piercing nuts 24 and 24 or the self-piercing nuts 24 and 24 themselves as the reference point 28. Become.

  Further, since the self-piercing nuts 24, 24 are the reference point 28 for bending the steel pipe W, the positional accuracy is high, and the self-piercing nuts 24, 24 are fastened to the stay 30 which is a vehicle body part of the automobile. The coupling accuracy of the 29 and the stay 30 is improved.

  In addition, the bending portion 29b, which is a portion of the front side frame 29 that is bent, is a portion that is coupled to the front subframe 33, which is a vehicle body part, so that the front side frame 29 is bent accurately. In addition to improving the coupling accuracy of the front side frame 29 and the front subframe 33, the displacement of the mounting position of the engine 36 supported by the front subframe 33 can be reduced.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the steel pipe guiding means of the present invention is not limited to the guide rollers 12 of the embodiment, and any means such as a die for guiding the steel pipe W to be movable in the longitudinal direction can be adopted.

  Further, the steel pipe W of the embodiment is not limited to the front side frame 29 of the automobile, and may be a member for any use.

  Further, the reference point 28 of the present invention is not limited to the hole 26 of the steel pipe W formed by the self-piercing nut 24 of the embodiment or the self-piercing nut 24 itself, and includes any object that can be detected by the position detecting means 27. It is.

12 Guide roller (steel pipe guiding means)
13 High-frequency heating coil (heating means)
14 Cooling device (cooling means)
15 Bending device 17 Chuck (gripping means)
18 Grasping point 24 Self-piercing nut
26 hole 27 position detection means 28 reference point 29 front side frame 30 stay (body parts)
33 Front subframe (body parts)
41 Processing point W Steel pipe

Claims (4)

A steel pipe guide means (12) for guiding the straight steel pipe (W) so as to be movable in the longitudinal direction, and a heating means (13) arranged on the downstream side of the steel pipe guide means (12) for heating the steel pipe (W). ), A cooling means (14) disposed downstream of the heating means (13) to cool the steel pipe (W), and a gripping point of the steel pipe (W) downstream of the cooling means (14) ( 18) the gripping means (17), the bending device (15) for moving the gripping means (17) in a three-dimensional space, and the positions of the reference points (28) formed on the steel pipe (W). A position detecting means (27) for optically or magnetically detecting,
The steel pipe (W) is formed by roll forming, and the reference point (28) is formed at the time of roll forming of the steel pipe (W) or the self-piercing nut (24) fixed at the time of roll forming of the steel pipe (W). The gripping means (17) grips the gripping point (18) of the steel pipe (W) so as not to move relative to the gripping means (17), and a position detection means (27 ) Detects that the reference point (28) has reached a predetermined position, the bending device (15) moves the gripping means (17) to apply a bending moment to the steel pipe (W). An apparatus for hot working a steel pipe, wherein the steel pipe (W) is bent at a machining point (41) in the vicinity of the heating means (13) . Before SL self pierce nut (24) or said bore (26) is characterized in that it is fastened to the vehicle body part (30) of a motor vehicle, hot working apparatus of a steel pipe according to claim 1. Portion to be bent before Symbol steel (W) is characterized by a portion which is coupled to the vehicle body part (33) of a motor vehicle, hot working apparatus of a steel pipe according to claim 1 or claim 2. Before Symbol steel (W) is characterized by a front side frame (29) of a motor vehicle, hot working apparatus of a steel pipe according to any one of claims 1 to 3.

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