JP2013027880A - Apparatus and method for bending hollow shape - Google Patents

Abstract

A hollow shape bending apparatus and a hollow shape bending method capable of easily bending a hollow shape member or a semi-hollow shape member with a simple configuration and having less cross-sectional deformation due to bending. provide.
A hollow shape bending apparatus 10 includes a first roll 20 and a second roll 21 arranged along a feeding direction A of a work 60, and the first roll 20 and the first roll 20 sandwiching the work 60. A pressing roll 22 which is a third roll arranged on the opposite side of the second roll 21 and in the middle of the rolls 20, 21, and the third roll 22 can be moved in the pressing direction B. The core metal 40 is inserted into the work 60 in advance, and the tip surface of the core metal 40 is closer to the second roll 21 side than the contact point T1 of the push roll 22 with the work 60, and the second roll. It is held on the contact point T1 side from the line L connecting the center points CP of the roller 21 and the push roll 22.
[Selection] Figure 3

Description

  The present invention relates to a hollow shape bending apparatus and a hollow shape bending method for bending a hollow shape member or a semi-hollow shape member made of, for example, aluminum with a predetermined radius of curvature.

  In recent years, due to diversification of products, quality improvement in the cross-sectional shape and appearance of products bent at a predetermined radius of curvature R has been required, and the types of shapes have been diversified.

For example, a hollow shape or a semi-hollow shape (hereinafter simply referred to as a hollow shape) formed of an extruded shape of aluminum is known. Aluminum extruded profiles have many advantages such as being able to form complex shapes, being lightweight, not rusting, and looking good. Therefore, in recent years, it has been used in various fields and places in place of conventional iron products.
As an example, it is often used as a structural material for railings, shelters, carports, side guards, gondola vibration control devices, etc., and these are bent and used with an appropriate radius of curvature R as required.

  Here, when a hollow shape or the like is bent into an R shape, in the case of the hollow shape or the like, the cross-sectional shape is deformed differently from the solid material.

  In more detail, depending on the radius of curvature, the mechanical properties of the material, and the cross-sectional shape, the flange that forms the inner surface that is the inner side and the outer surface that is the outer side of the bending direction is deformed to the hollow side, The web connecting the inner surface and the outer surface is deformed to the outside of the hollow portion.

Further, during bending, a compressive force acts on the inner side and the outer side of the bending neutral shaft, whereas a tensile force acts on the outer side. For this reason, the inner surface side flange may be buckled or wrinkled in the direction perpendicular to the longitudinal direction of the hollow profile or the like, or may be wrinkled more than the inner surface of the web.

Conventionally, when bending a hollow shape member with a predetermined radius of curvature R, various bending methods have been conventionally performed so as not to cause wrinkles or the like.
As an example, a bending method using a draw bender is known (for example, see Patent Document 1).
As disclosed in Patent Document 1, the bending process using a draw bender is a work material such as a hollow material such as a pipe (hereinafter referred to as a workpiece), which is formed into an inner mold that takes into account the spring back. It is bent along by moving along the winding. In this case, a cored bar (also referred to as a mandrel) is inserted into the workpiece as necessary, and bent at a predetermined radius of curvature R while preventing cross-sectional deformation due to bending.
This bending method is suitable for mass production.

  However, the bending method using the draw bender has a problem that it is not suitable for a small-volume product, a case where the radius of curvature R is large, or a case where the material of the workpiece varies. In other words, a mold corresponding to each curvature radius R is required each time, and the production is very expensive. In addition, the draw bender has restrictions on the size of equipment and mold, and as a result, the product having a large radius of curvature R is not suitable because the mold becomes large.

As another bending method, a push-through bending method is known (see, for example, Patent Document 2).
In this method, the workpiece is pushed from behind through a fixed die and a movable die and the position and orientation of the movable die is moved to bend, but it can be used for a relatively small workpiece. However, in the case of a long length, there is a limit because the workpiece is buckled by the pressing force from the rear. In the case of a workpiece having a large cross-sectional shape, there has been a problem that the apparatus becomes large.

On the other hand, a bending method by three-roll bending is known.
In this three-roll bending, as shown in FIGS. 12A and 12B, the first roll 120 disposed behind the workpiece 160 that is a hollow shape in the feeding direction A and the front in the feeding direction A are used. The second roll 121 arranged on the opposite side of the first roll 120 and the second roll 121 with the workpiece 160 interposed therebetween, and in the middle portion between the first roll 120 and the second roll 121 The three rolls 122 are arranged, and the three rolls 120, 121, 122 are arranged in a triangular shape in plan view.
Each of the three rolls may be a roll that is driven in conjunction with the power unit, although each roll is rotatable. However, only one roll, for example, the third roll 122 may be a drive roll, or the first roll The roll 120 and the second roll 121 may be drive rolls.

  Then, as shown in FIG. 12A, the vertex roll, that is, the third roll 122 moves in the direction orthogonal to the line connecting the first roll and the second roll, that is, the pushing direction indicated by the arrow B. It is configured so as to constitute a push roll. Then, the push roll 122 is pressed against the workpiece W, and a bent product having a curvature radius R of an arbitrary size can be made according to the movement distance of the third roll in the B direction.

  However, in the three-roll bending, for example, when a workpiece that is a hollow shape member made of aluminum is bent with a radius of curvature R, the workpiece is crushed because it is bent while applying pressure with the push roll 122 in the state as it is. End up. Therefore, there is a problem that the work must be filled with a crush prevention material or the like.

  Therefore, in order to prevent the workpiece from being crushed when the workpiece is bent with three rolls, for example, sand is filled into the workpiece as an anti-crush material, and then bending is performed. . In this method, sand is filled into the work from a sand filling machine installed at a predetermined position. And the sand is extracted from the inside of a workpiece | work after completion | finish of a bending process.

However, this method of filling and bending sand has many problems as follows.
1. Since sanding and sand removal occur for each workpiece, it takes a lot of man-hours including preparation.
2. Since the work is filled with sand, the work becomes heavy.
3. Work must be transported to the sanding machine, and after sanding, the work that has become heavy due to the sand must be transported to the bending machine, resulting in heavy labor and poor work efficiency. .
4). In order to fill the workpiece with sand, the workpiece must be erected, a support device or the like is required, and the device becomes large and requires a lot of space.
5. Since the workpiece is bent while the sand is filled inside, it is not possible to obtain a predetermined radius of curvature R at one time, and it is necessary to pass through each roll until the radius of curvature R is obtained. It increases, requires a lot of man-hours, and the work efficiency is poor.

Next, the procedure of the bending method in the sand filling method by three-roll bending will be described with reference to FIGS.
First, as a first step, the workpiece 160 is preliminarily filled with sand by a sand filling machine.
As a second step, as shown in FIG. 12A, the workpiece 160 is inserted between the first and second rolls 120 and 121 and the push roll 122 and set at a predetermined position, and the push roll 122 is moved to a predetermined position. Push to the position.

  As a third step, as shown in FIG. 12 (B), the first and second rolls 120 and 121 are driven in the direction of the arrow r1 and the push roll 122 is driven in the direction of the arrow r2 to feed the work 160.

As a fourth step, the radius of curvature Ra is confirmed in a state where the push roll 122 is pushed as shown in FIG. 13A for the workpiece that has passed through each roll in the third step. As a result, when the radius of curvature Ra is large, the workpiece 160 is indicated by an arrow A1 by rotating the first and second rolls 120 and 121 in the direction of the arrow r11 and the push roll 122 in the direction of the arrow r12 in order to bend further. Send in the opposite direction.
As a result, the curvature radius Ra is corrected to Rb having a small curvature radius.

Next, the above third and fourth steps are repeated until the workpiece 160 has the required radius of curvature R.
Then, as shown in FIG. 13B, a workpiece (product) 160A having a predetermined curvature radius R can be obtained. The predetermined radius of curvature R is measured with a measuring tool (not shown), for example, by measuring the bulging dimension H with respect to a line connecting the inner end portions of the workpiece (product) 160 finished to the length L. It is.

In the three-roll bending sand filling method, as described above, man-hours related to filling and discharging of sand are required. Therefore, in the present invention, instead of filling the sand, a core metal that is normally used for a roll bender is used. The above-mentioned problems are solved by using.
In the conventional three-roll bending, it is considered that it is difficult to use the cored bar because the workpiece is bent and deformed from the contact point with the third roll or a slightly rearward position in the feeding direction. The core metal was not considered for use.
In addition, as described above, in the case of three-roll bending, since it is used for a small amount of bending processing, an accurate pressing amount of the pressing roll cannot be grasped in advance. The use of a mandrel has not been conceived because it requires operation.
In addition, according to this 3 roll bending, it is also possible to change a curvature radius in the middle of the longitudinal direction of a workpiece | work.

Public Utility Sho 61-72321 JP-A-9-29327

  However, the above-described bending by the bending bender, push-through bending, and three-roll bending have advantages and problems. Accordingly, there is a demand for the development of a bending device and a bending method for hollow shapes that can improve the productivity by integrating only the advantages of each bending method.

  An object of the present invention is to provide a hollow shape bending apparatus and a hollow shape bending method which can easily bend a hollow shape with a simple configuration and have a small cross-sectional deformation due to bending. There is.

The present invention relates to a three-roll bending, and specifically, the hollow shape bending apparatus is arranged along the feed direction of the hollow shape and can send the hollow shape forward in the feed direction. 1st roll and 2nd roll, and the opposite side of said 1st roll and 2nd roll on both sides of said hollow shape material, and it arranges in the middle part of these 1st roll and 2nd roll A third roll, wherein one or more of these rolls are rotationally driven to deliver a hollow profile, the third roll being the first roll and the second roll It is configured to be movable in a direction perpendicular to the line connecting the two, and a cored bar is inserted in advance from the rear in the delivery direction before bending the hollow profiled material inside the hollow profiled material, From the point of contact of the third roll with the hollow profile, the second roll Wherein the held the to those contact side of the line and connecting the center points between said second roll and the third roll at roll side closer.

  In addition, the method of bending a hollow profile according to the present invention includes a first roll and a second roll in which the hollow profile is disposed along a delivery direction thereof, and the first roll sandwiching the hollow profile. And a bending method of a hollow member that is bent with a third roll disposed on the opposite side of the second roll and in the middle portion between the first roll and the second roll, the hollow A first step of setting a shape member between the first roll and the second and third rolls and inserting a cored bar into the hollow shape member; and the third roll as the hollow shape member. A second step of setting a predetermined radius of curvature by moving in a direction orthogonal to the feeding direction of the first, and rotating one or more of the first roll, the second roll and the third roll to rotate the The hollow shape is sent forward and bent. The fourth step of extracting the cored bar from the hollow profile, the fifth step of measuring the radius of curvature of the bent hollow profile, and the radius of curvature of the hollow profile after the bending When the diameter is larger than the allowable dimension, a sixth step is provided in which the moving distance of the third roll is increased without removing the hollow profile, and the rolls are supplementally bent by reversely rotating the rolls as they are. And

In addition, the method of bending a hollow profile according to the present invention includes a first roll and a second roll in which the hollow profile is disposed along a delivery direction thereof, and the first roll sandwiching the hollow profile. And a bending method of a hollow member that is bent with a third roll disposed on the opposite side of the second roll and in the middle portion between the first roll and the second roll, the hollow A first step of setting a shape member between the first roll and the second and third rolls and inserting a cored bar into the hollow shape member; and the third roll as the hollow shape member. A second step of setting a predetermined radius of curvature by moving in a direction orthogonal to the feeding direction of the first, and rotating one or more of the first roll, the second roll and the third roll to rotate the The hollow shape is sent forward and bent. The fourth step of extracting the cored bar from the hollow profile, the fifth step of measuring the radius of curvature of the bent hollow profile, and the radius of curvature of the hollow profile after the bending Is larger than the allowable dimension, the hollow profile is set again on the first roll, the second roll and the third roll, and the third roll is moved during the third step without using the cored bar. A sixth step of increasing the distance from the distance and feeding the hollow profile forward to perform replenishment bending.
In the above description, the semi-hollow shape means a shape in which the hollow portion X does not form a closed space and is opened at a portion Y of the shape as shown in FIG.
In addition to setting the predetermined radius of curvature to bend without changing the radius of curvature of the hollow shape member, or when bending only a part of the hollow shape material, the third step is performed during the third step. This includes the case where the radius of curvature is changed in the middle of the hollow profile by changing the amount of movement of the roll.

Since the bending apparatus of the hollow shape material of the present invention is configured as described above, the hollow shape material in which the core metal is inserted is inserted between the first roll and the second roll and the third roll. It is set, and the third roll is moved to rotate the roll while pressing the hollow profile, and bending is performed. At this time, the tip surface of the cored bar is closer to the second roll side than the contact point with the hollow shape member of the third roll, and from the line connecting the center points of the second roll and the third roll. Since it is held on the contact point side, the core bar bends with the contact point with the hollow shape member of the third roll as a fulcrum, so that the hollow shape member is smoothly bent while maintaining the cross-sectional shape. As a result, the hollow profile is bent with the contact point as a base point.
As described above, since the cored bar is positioned near the position where the bending process is performed, it is difficult for the workpiece to be deformed in cross section during the bending process. As a result, the bending of the hollow shape can be easily performed with a simple configuration.
Further, in the three-roll bending of the present invention, when the bending amount is adjusted by additional bending after finishing the bending process, the cored bar is removed after the bending process and the cored bar is formed without the cored bar. Since it is possible to perform replenishment processing without using, additional replenishment bending can be easily performed. As a result, it is possible to obtain the effect of reducing the man-hours for filling and removing sand and reducing the number of processing steps.

1 is an overall plan view showing an embodiment of a hollow shape bending apparatus according to the present invention. FIG. 2 is a front view illustrating a guide roller of a hollow shape bending apparatus and a rear side portion (work supply unit side) in a feeding direction in a view taken along an arrow II in FIG. 1. It is a top view which shows the principal part of the bending apparatus of the hollow shape material of the said embodiment. It is a longitudinal cross-sectional view which shows the engagement state of a 1st roll and a workpiece | work by IV arrow view in FIG. It is a perspective view which shows the relationship between the workpiece | work of the bending apparatus of the hollow shape material of the said embodiment, and a metal core. FIG. 6A shows a first process, and FIG. 6B shows a second process. FIG. 7A shows a third step and FIG. 7B shows a fourth step in the bending process of the hollow shape bending apparatus of the embodiment. It is a figure which shows the 5th process of the procedure of the bending process of the bending apparatus of the hollow shape material of the said embodiment. It is a figure which shows the 6th process of the procedure of the bending process of the bending apparatus of the hollow shape material of the said embodiment. It is a flowchart which shows the procedure of the bending process of the bending apparatus of the hollow shape material of the said embodiment. It is a comparison figure of the cross-sectional shape of the workpiece | work as a comparative example and the bending process by the bending apparatus of the hollow shape material of the said embodiment, FIG. 11 (A) is a measurement location, FIG.11 (B) is the measurement in each measurement location. It is a figure which shows a value. FIG. 12A shows a second step, and FIG. 12B shows a third step, showing a bending step by a general three-roller sand filling method. FIG. 13A is a fourth step, and FIG. 13B is a conceptual diagram showing a method for measuring the curvature radius R of a workpiece. Examples of semi-hollow shapes included in hollow shapes

  Hereinafter, an embodiment of a bending apparatus for a hollow profile according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, in the bending apparatus 10 of the present embodiment, a first roll 20 that supports and feeds a work 60, a second roll 21, and a push roll 22 that is a third roll are triangular in plan view. It is the bending processing apparatus by the three roll arrange | positioned in.
And while the workpiece | work 60 is penetrated between each roll 20,21,22, it is comprised inside the workpiece | work 60 so that it can be bent in the state which the core metal 40 was hold | maintained in the predetermined position.
Of these rolls, the first roll 20 and the second roll 21 are rolls that rotate with a driving force, and the push roll 22 is a driven roll that does not have a driving force.

  Here, the left side in FIG. 1 is the rear side in the feed direction of the work 60 that is a hollow shape, and the right side is the front side in the feed direction of the work 60.

The bending apparatus 10 includes a table 11.
On the upper surface of the table 11, the first roll 20 and the second roll 21 are arranged along the workpiece delivery direction indicated by arrow A, on the rear side in the delivery direction and on the front side in the delivery direction. The first roll 20 and the second roll 21 are provided so as to be rotatable along the rotation direction indicated by the arrow r1.
Further, as shown in FIG. 4, a work groove 23 that is a guide groove is formed in the first roll 20 and the second roll 21, and the work 60 is placed in the work groove 23. It is inserted and sent out.
4 shows only the engagement state between the first roll 20 and the work 60, the engagement between the second roll 21 and the work 60 and between the push roll 22 and the work 60 is also shown in FIG. It is substantially the same.

On the upper surface of the table 11, a push roll 22 is provided at a position opposite to the first roll 20 and the second roll 21 across the work 60 to be fed out.
That is, the push roll 22 is arranged at an approximately middle position between the first roll 20 and the second roll 21 and is indicated by an arrow B in a direction orthogonal to a line connecting the first roll 20 and the second roll 21. It is provided so as to be movable in the pushing direction shown.

The push roll 22 is provided on the base 12, and a part of the base 12 extends between the first roll 20 and the second roll 21 on the one end side of the table 11. Has been.
The base 12 is provided with a screw mechanism 13, and the base 12 can be moved in the roll pressing direction B by the screw mechanism 13. The screw mechanism 13 is driven by a drive motor (not shown).

As shown in FIGS. 1 and 2, a wire fixing portion 15 for fixing a wire 42 attached to the rear of the cored bar is disposed at a predetermined position on the rear side in the delivery direction of the table 11. Between the section 15 and the table 11, for example, two feeding-side guide mechanisms 16 that support and guide the workpiece 60 when it is fed are arranged at two locations.
Note that the number of the feed-side guide mechanisms 16 is not limited to two, and two or more may be arranged corresponding to the size and length of the workpiece 60.

As shown in FIG. 2, each feed-side guide mechanism 16 includes a stand 16 </ b> A that is erected and a guide roller 16 </ b> B that is rotatably supported by the stand 16 </ b> A within a horizontal plane. The work 60 is guided and sent out on the guide roller 16B.
The feed-side guide mechanism 16 is arranged so that the axis of the guide roller 16B is substantially perpendicular to the workpiece feeding direction A.

On the front side of the table 11 in the workpiece feeding direction, receiving side guide mechanisms 17 for receiving and guiding the workpiece 60 bent at the curvature radius R are arranged, for example, at two locations.
That is, these receiving side guide mechanisms 17 are configured substantially the same as the feeding side guide mechanism 16, and are configured by a receiving base 17A and a guide roller 17B that is rotatably supported by the receiving base 17A in a horizontal plane. Has been. The receiving side guide mechanism 17 is such that the workpiece 60 supplied from the rear side is bent by the first roll 20, the second roll 21 and the push roll 22, and during the bending process, and the finished product A guide roller 17B is arranged in such a direction that the product can be guided. That is, each guide roller 17B is disposed so as to be substantially orthogonal to the bent workpiece.
The guide mechanisms 16 and 17 have a movable stand type structure and can be freely installed at appropriate positions depending on the radius of curvature and the length of the workpiece.

  Next, based on FIG. 3, the first roll 20, the second roll 21, the push roll 22, the work 60, and the cored bar 40 inserted into the work 60, which are the main parts of the present invention. The relationship will be described in detail.

A cored bar 40 is inserted into the work 60 in advance, and the tip end surface 40A of the cored bar 40 is closer to the second roll 21 side than the contact point T1 of the push roll 22 with the work 60 and It is held on the contact point T1 side between the pressing roll 22 and the workpiece 60 with respect to the line L connecting the center points CP1, CP2 of the second roll 21 and the pressing roll 22.
More specifically, when the workpiece 60 is set at the initial position, the cored bar 40 is positioned by the S dimension from the center line CL of the push roll 22 in the direction orthogonal to the feeding direction A, that is, from the contact point T1. It protrudes and is provided in the 2 roll 21 side.

Further, the rear end surface 40B of the cored bar 40 is arranged to be located on the rear side in the delivery direction from the contact point T2 with the work 60 of the first roll 20.
A wire 42 as a holding member is attached to the rear end surface 40B of the cored bar 40, and the cored bar 40 is held at a predetermined position by the wire 42 even during the bending process.
However, the metal core 40 is held only during the bending process by the first roll 20, the second roll 21, and the push roll 22, and after the bending process is completed, the core bar 40 is extracted from the work 60. ing.
In addition, the holding member may not be the wire 42 but may be constituted by a rod-shaped member, for example.

  As shown in FIG. 4, a workpiece groove 23 corresponding to the workpiece 60 is formed on the side surface of the first roll 20 as described above so that the workpiece 60 is inserted.

The workpiece groove 23 is formed by each member as shown in FIG.
That is, as shown in FIG. 4, the first roll 20 is integrated with a lower large-diameter member 25 provided on the table 11 via a bearing (not shown) and an upper surface of the lower large-diameter member 25. A lower groove constituting member 26 provided on the upper surface, a groove width adjusting ring 27 arranged on the upper surface of the lower groove constituting member 26, an upper groove constituting member 28 arranged on the upper surface of the groove width adjusting ring 27, and And an upper large-diameter member 29 provided integrally on the upper surface of the upper groove constituting member 28. Each member 26 to 29 is fixed to a shaft 30 rotatably connected to a motor (not shown) via a key member (not shown).
The workpiece groove 23 is opposed to the upper surface of the lower groove constituting member 26 facing the lower surface of the work 60, the lower surface of the upper groove constituting member 28 facing the upper surface of the work 60, and one side surface of the work 60. The groove width adjusting ring 27 is formed to have a U-shaped cross section with one end face thereof.

  Also, the structure of the second roll 21 and the push roll 22 is substantially the same as the structure of the first roll 20, and the second roll 21 and the push roll 22 have the same work surface as that described above. Grooves are formed.

  And the groove part 23 for workpiece | work can each be made to respond | correspond to the multiple types of workpiece | work 60 from which a magnitude | size changes suitably by changing the thickness dimension and outer-diameter dimension of the groove width adjustment ring 27. FIG.

  Here, the lower groove constituting member 26, the groove adjusting ring 2 7 and the upper groove constituting member 28 are, for example, “MC nylon; trade name” obtained by polymerizing and molding a main raw material nylon monomer, which is an engineering plastic, under atmospheric pressure. The side surface of the work 60 is in contact with the groove adjusting ring 2 7 and the lower groove constituting member 26, so that the work 60 can be reliably delivered.

  The cored bar 40 is formed in a cross-sectional shape corresponding to the inner diameter shape of the workpiece 60 and is inserted into the workpiece 60 along the insertion / extraction direction indicated by the arrow AA in FIG. The cored bar 40 is made of polyacetal (trade name: Duracon), which is one of typical materials for engineering plastics, and has a shape corresponding to the internal shape 60 </ b> A of the workpiece 60. This Duracon has an excellent balance of heat resistance, mechanical properties, wear resistance, etc., high mechanical strength, and excellent machinability. It is a material that can be processed relatively easily.

When inserting the cored bar 40 into the workpiece 60, it is preferable to apply a predetermined lubricating oil to the outer periphery of the cored bar 40.
In addition, the insertion of the cored bar 40 into the work 60 may be performed by feeding the work 60 to the first roller 20, the second roller 21, and the push roll 22 side after being inserted in advance in the feed direction rear side of the table 11. Alternatively, the cored bar 40 may be inserted after the workpiece 60 is set at a predetermined position of each of the rollers 20, 21, and 22.
When the core metal 40 is supported by the wire 42, the core metal 40 is moved to a predetermined position using a bar-shaped member as appropriate, and when the core metal 40 is supported by a bar-shaped member instead of the wire 42 Set the workpiece while inserting.

  As shown in FIG. 2, the rear end of the cored bar 40 is connected to the tip of the wire 42 via, for example, a ring-shaped attachment 41. The rear end portion of the wire 42 is connected to a hook 43 that is fixed to the wire fixing portion 15.

  Accordingly, the cored bar 40 is always held at a predetermined position in the work 60, and when the wire 42 is extended to the maximum, the first roll 20, the second roll 21 and the push roll 22 are set at predetermined positions. In the workpiece 60, the rear side of the cored bar 40 in the feeding direction is a position behind the contact point between the first roll 20 and the workpiece 60, and the front side of the cored bar 40 in the feeding direction is the push roll 22 and the workpiece 60. The contact between the second roll and the work 60 is located at a position close to the contact between the push roll 22 and the work 60.

Here, the center-to-center distance between the first roll 20 and the second roll 21 is, for example, 600 mm, and the first roll 20 and the push roll 22 and the second roll 21 when the push roll 22 is in the initial position. In the case of the apparatus in which the distance between the pressing roll 22 and the pressing roll 22 is set to 600 mm, the cored bar 40 is formed to be approximately 500 mm, and the front end thereof is approximately 40 mm forward from the contact point between the pressing roll 22 and the work 60. It is held so as to be in a position protruding to the side. The approximately 40 mm is the projecting dimension S from the contact point T1.
This state is maintained until the bending of the workpiece 60 starts and ends.

  Next, a bending procedure of the profile bending apparatus 10 of the present embodiment will be described based on the flowchart of FIG. 10 with reference to FIGS.

First, when bending of the workpiece starts, in the first step, as shown in FIG. 6 (A), the workpiece 60 is passed through the first roll 20, the second roll 21, and the push roll 22 at a predetermined position. Set to. At this time, the cored bar 40 is inserted into the workpiece 60.
The push roll 22 is in a standby state at the initial position. The cored bar 40 has its rear end 40 </ b> B fixed with a wire 42.

Next, in the second step, as shown in FIG. 6B, the push roll 22 is moved in the push direction indicated by the arrow B and pushed to a predetermined position.
At this time, the radius of curvature R of the product is determined by this pushing amount. The amount of push-in is determined in consideration of the springback.

  Thereafter, in the third step, as shown in FIG. 7A, the first roll 20 and the second roll 21 are pushed again in the direction of the arrow r1 while the work 60 is pressed by the push roll 22, respectively. The rolls 22 are respectively rotated along the direction of the arrow r2, and the work 60 is sent out and bent with a set radius of curvature R.

Next, in the fourth step, as shown in FIG. 7B, the cored bar 40 is extracted from the workpiece 60 in the direction of the arrow A1.
At this time, the operator slowly pulls the wire 42 and removes the cored bar 40 from the workpiece 60.

Thereafter, in the fifth step, the state of the fourth step is completed, that is, in a state where the rear end of the work 60 is held without being removed from the first roll 20, the second roll 21, and the push roll 22. Whether or not the radius of curvature R of the bent portion at the front end of the work 60 falls within the set allowable dimension range as shown in FIG. Measure with the measuring tool 65.
In this case, the measuring tool 65 having the total length l is pressed against the inner center portion of the front end of the workpiece 60 which has been bent, and the side surface along the longitudinal direction of the measuring tool 65 for measuring the radius of curvature R and the inner side of the workpiece 60. The gap dimension h with the central part is measured to determine whether or not it falls within the allowable dimension range.
The gap dimension h is determined in advance based on the curvature radius R of the workpiece 60 and the total length l of the gauge 65.

When it is determined that the measurement result does not fall within the set allowable dimension range (the bending is insufficient) (in the case of N), the process proceeds to the sixth step.
When it is determined that the measurement result is within the set allowable dimension range (in the case of Y), the process proceeds to the seventh step.

In the sixth step, as shown in FIG. 9, the workpiece that has been bent but is determined to be insufficiently bent, without removing the workpiece once bent, increases the moving distance of the third roll 22, The rolls 20, 21, 22 are replenished by reversing the rolls as they are.
However, the cored bar 40 is not inserted into the workpiece during the second bending process, that is, the supplementary bending.

Next, whether or not the curvature radius R of the workpiece 60 is within the set allowable dimension range is determined for the workpiece that has been bent again in the sixth step, as in the fifth step. Measure with the R measuring tool 65 and judge.
When it is determined that the measurement result does not fall within the allowable dimension range of the set numerical value (the bending is insufficient) (in the case of N), the bending process is performed again in the same manner as in the sixth step, and the setting is performed. Repeat until the value is within the allowable dimension range.
When it is determined that the measurement result is within the set allowable dimension range (in the case of Y), the process proceeds to the seventh step.

  In the seventh step, the finished workpiece 60 that has been bent is taken out and becomes an end.

Here, when re-bending is performed on a workpiece that is determined not to fall within the set allowable dimension range (bending is insufficient), it is once bent as in the sixth step. Instead of removing the workpiece, it is not necessary to increase the moving distance of the third roll 22 and perform the supplementary bending by rotating the rolls 20, 21, 22 as they are.
That is, after the work 60 once bent is taken out, it is inserted again into the work groove 23 of the first roll 20, the second roll 21 and the push roll 22 in the initial state, and the moving distance of the push roll 22 is increased. A method of increasing and moving in the pushing direction B and performing a second bending process, that is, supplementary bending, as in the third step may be used. In this case, the cored bar 40 is not used.
Even in this manner, the workpiece 60 having the curvature radius R can be obtained.

  Next, the results of measuring the outer surface of the work 60 after bending using a flatness measuring jig (gap gauge) (not shown) and confirming the quality (confirming the cross-sectional shape) are shown in FIG. I will explain.

  For the measurement of the workpiece, five test specimens were prepared for each of the present embodiment and the comparative example, and the average value is shown in FIG.

In this embodiment and the comparative example, the test body is an extruded material of an aluminum alloy (JIS6063T1) having a cross-sectional shape shown in FIG.
Further, the bending direction was such that the surface I on the side shown in FIG. 11A was the inner surface (bending radius center side) when bent.
Further, the material has a length L = 2813 mm and a bending radius of curvature R = 1722 mm.

In this embodiment, the bending process is performed using the cored bar as described above, and the supplementary bending process in step 6 is not performed.
And the said protrusion length dimension S ahead of the delivery direction of a metal core was 40 mm.
In the comparative example, bending was performed by the method of filling the sand described above as a conventional example.

  As shown in FIG. 11 (A), with respect to the three side surfaces, the maximum bulging portion at the center position of a, b, and c (deformation in the longitudinal direction) with respect to the deformation dimensions of the surface before and after bending is performed. The position of the large part) was measured.

  As a result, as shown in FIG. 11B, the bending process using the cored bar 40 of the present embodiment shows superior numerical values at any measurement position of a, b, and c. It has been demonstrated that better bending products with less deformation can be obtained.

  Since the shape bending apparatus 10 of the first embodiment is configured as described above, according to this, the following effects can be obtained.

  (1) The work 60 in which the core metal 40 is inserted is set between the first roll 20, the second roll 21, and the push roll 22, and each roll 20 is pressed while pressing the work 60 with the push roll 22. , 21 and 22 are rotated to perform bending. At this time, the front end surface 40A of the cored bar 40 is closer to the second roll 21 side than the contact point T1 of the push roll 22 with the work 60, and each center point CP1, between the second roll 21 and the push roll 22 is set. Since the workpiece 60 is held on the contact point T1 side from the line L connecting CP2, the workpiece 60 is bent with the tip surface 40A of the cored bar 40 as a base point. Therefore, since bending is performed in a state where the cross-sectional shape of the workpiece is constrained from the inner surface side, cross-sectional deformation is unlikely to occur. Further, the radius dimension can be set by the pressing amount of the push roll 22, and the bending process with the set radius can be performed by a small bending process, for example, a single bending process. As a result, the workpiece 60 can be easily bent with a simple configuration, and the set radius of curvature R can be obtained in a single bending step, so that productivity can be improved.

  (2) Since the workpiece 60 is bent using the tip end face 40A of the cored bar 40 as a bending base point, the cored bar 40 is not bent, whereby the cored bar 40 can be easily moved after the bending process is finished. 60 can be extracted.

  (3) A cored bar 40 is inserted into the workpiece 60. The leading end face 40A of the cored bar 40 is held at the position as described above, and the rear end face 40B of the cored bar 40 is a first end. The roll 20 is disposed on the rear side in the delivery direction from the contact point T2 with the work 60. Therefore, it is not necessary to make the cored bar 40 longer than necessary, and it is possible to contribute to saving of the material of the cored bar.

  (4) The rear end face 40 </ b> B of the cored bar 40 is connected to the wire 42, and the end of the wire 42 is fixed to the wire fixing part 15. Since the cored bar 40 is always fixed at a predetermined position in the workpiece 60, the workpiece 60 is always bent from a certain position. As a result, a stable product can be obtained.

  (5) The rear end face 40 </ b> B of the cored bar 40 is connected to the wire 42, and the end of the wire 42 is fixed to the wire fixing part 15. When the work 60 is bent, the core metal 40 is also moved by being pulled by the work W. However, since the core metal 40 is firmly pulled by the wire 42, the core metal 40 is securely held at a predetermined position. Can do.

  (6) The cored bar 40 corresponds to the workpiece 60 to be bent, and can be extracted after being bent. Therefore, when bending another workpiece 60 having the same size and shape, the extracted cored bar 40 can be used again. There is no need to newly form the cored bar 40 each time in accordance with the workpiece 60. As a result, material saving and labor saving can be achieved.

  (7) If the measurement result of the radius of curvature R of the work 60 after bending is not within the set allowable dimension range (the bending is insufficient), the work 60 is bent again. Can do. At that time, the pushing amount of the push roll 22 can be reduced, so that the bending speed can be increased and the dimensions can be easily finely adjusted.

(8) In the profile bending apparatus 10 of this embodiment, the sand-related processes are eliminated and only the insertion process of the cored bar 40 and the extraction process of the cored bar 40 are required as compared with the bending method of filling the sand. It can be greatly reduced and work efficiency can be improved.
As a result of actual verification, when comparing both operations from a time perspective, when changing from sanding and sand removal to cored bar 40, it can be reduced by about 40%. The efficiency could be improved.
In addition, since the shape bending apparatus 10 of this embodiment can perform R bending in one operation, it only takes about half the work time compared to the bending method of filling sand, and the bending time is greatly reduced. Including the above operations, the entire bending process was reduced by about 35% when compared.

  (9) Quality confirmation (confirmation of cross-sectional shape) of the workpiece 160 bent by the sand filling method and the workpiece 60 (product) bent by the shape bending apparatus 10 of the present embodiment is a result of actual measurement. According to this, the bending process using the cored bar 40 of the present embodiment shows a superior numerical value, and as a result, there is little deformation of the bent shape and a more excellent bent product can be obtained. .

  (10) In the profile bending apparatus 10 of the present embodiment, the work after the work 60 is bent only needs to cut both end portions by a predetermined size. For example, after sand removal, the work is peeled off. As compared with cutting both ends at predetermined dimensions, the number of processing steps can be reduced.

  The present invention has been described above with reference to the above embodiment, but the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. In addition, the present invention includes a combination of some or all of the configurations of the above embodiments as appropriate.

  For example, in the above-described embodiment, an aluminum square pipe-shaped member is used as the work 60 that is a hollow shape, but the hollow shape has a semi-hollow cross section shown in FIG. 14 in addition to such a closed cross section. In addition, for example, a C-chan having a slit-like gap formed in a part of the work 60 on the upper surface along the longitudinal direction can also be used for bending.

  INDUSTRIAL APPLICABILITY The present invention can be used when, for example, a hollow aluminum material used for landscape products such as railings, shelters, ETC gantry and the like is bent at a predetermined radius.

DESCRIPTION OF SYMBOLS 10 Bending apparatus of hollow shape material 11 Table 15 Wire fixing part 20 1st roll 21 2nd roll 22 Push roll which is 3rd roll 23 Workpiece groove part which is a guide groove 27 Groove adjustment ring 40 Core metal 42 Holding | maintenance Wire 60 as a member Workpiece as a hollow member A Workpiece delivery direction B Third roll pushing direction T1 Contact point between the push roll and the workpiece T2 Contact point between the first roll and the workpiece CP1 Center point of the second roll CP2 Center point of the third roll (push roll) L Line connecting the center point of the second roll and the center point of the push roll S Projection dimension of the core metal from the center point of the push roll r1 Rotation of the first roll and the second roll Direction r2 Rotation direction of the third roll (push roll) R Curvature radius

Claims (8)

A first roll and a second roll which are arranged along the delivery direction of the hollow profile and are capable of delivering the hollow profile forward in the delivery direction;
A third roll disposed on the opposite side of the first roll and the second roll across the hollow profile and in the middle of the first roll and the second roll, and these Any one or more rolls are rotationally driven to deliver the hollow profile;
The third roll is configured to be movable in a direction perpendicular to a line connecting the first roll and the second roll,
A cored bar is inserted into the hollow profile from the rear in the feeding direction before bending the hollow profile, and the tip end surface of the cored bar is a point of contact with the hollow profile of the third roll Bending of a hollow member characterized by being held closer to the contact point side than a line connecting the center points of the second roll and the third roll closer to the second roll side apparatus. In the bending apparatus of the hollow shape member according to claim 1,
A hollow member characterized in that the length of the metal core is formed such that the rear end surface of the metal core is arranged on the rear side in the delivery direction from the contact point with the hollow material of the first roll. Bending machine. The hollow shape bending apparatus according to claim 1 or 2,
One end portion of a holding member that holds the core metal inside the hollow shape member is connected to the rear end surface of the core metal, and the other end portion of the holding member is fixed to the rear of the hollow shape member supply portion. A hollow shape bending apparatus characterized by being made. In the bending apparatus of the hollow shape member according to claim 3,
A hollow shape bending apparatus according to claim 1, wherein the holding member comprises a wire member. In the bending apparatus of the hollow shape member as described in any one of Claims 1 thru | or 4,
Guide grooves corresponding to the hollow shape members are provided on the side surfaces of the first roll, the second roll, and the third roll, and these guide grooves have a plurality of types of the hollow shape members having different sizes. A hollow shape bending apparatus characterized by having a member combination structure that can be set to a size corresponding to each of the above. In the bending apparatus of the hollow shape member according to claim 5,
Each guide groove of the first roll, the second roll, and the third roll is formed by a groove adjustment ring capable of adjusting the depth and width of the guide groove, and each of the groove adjustment rings has an outer diameter dimension. And a plurality of types having different thickness dimensions are prepared in advance and are selectively used according to the size of the hollow shape member. A first roll and a second roll arranged in the delivery direction of the hollow profile, and the first roll and the second roll opposite to the first roll and the second roll across the hollow profile. A bending method of a hollow shape material that is bent with a third roll disposed in an intermediate portion of the second roll and the second roll,
A first step of setting the hollow profile between the first roll and the second roll and the third roll and inserting a cored bar into the hollow profile;
A second step of setting the predetermined curvature radius by moving the third roll in a direction orthogonal to the delivery direction of the hollow profile;
A third step in which one or a plurality of rolls among the first roll, the second roll and the third roll are rotationally driven to feed the hollow profile forward and bend;
A fourth step of extracting the cored bar from the hollow profile;
A fifth step of measuring the radius of curvature of the bent hollow profile;
When the radius of curvature of the hollow profile after bending is larger than the allowable dimension, the third roll is moved to the third roll without removing the hollow profile, and the roll is reversely rotated as it is to perform supplementary bending. A hollow shape material bending method comprising six steps. A first roll and a second roll arranged in the delivery direction of the hollow profile, and the first roll and the second roll opposite to the first roll and the second roll across the hollow profile. A bending method of a hollow shape material that is bent with a third roll disposed in an intermediate portion of the second roll and the second roll,
A first step of setting the hollow profile between the first roll and the second roll and the third roll and inserting a cored bar into the hollow profile;
A second step of setting the predetermined curvature radius by moving the third roll in a direction orthogonal to the delivery direction of the hollow profile;
A third step in which one or a plurality of rolls among the first roll, the second roll and the third roll are rotationally driven to feed the hollow profile forward and bend;
A fourth step of extracting the cored bar from the hollow profile;
A fifth step of measuring the radius of curvature of the bent hollow profile;
When the radius of curvature of the hollow profile after bending is larger than the allowable dimension, the hollow profile is set again on the first roll, the second roll, and the third roll, and the third without using the core metal. A hollow shape bending method characterized by comprising: a sixth step of increasing the number of rolls from the moving distance in the third step and feeding the hollow shape forward to perform supplementary bending. .

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