JPH06198348A - Roll bending method - Google Patents

Abstract

PURPOSE:To beautifully and easily bend a work with a wanted radius of curvature by fixing the length of work between bending rolls when the work is bent by a fixed center roll and a couple of bending rolls which are freely vertically and horizontally movable against the center roll. CONSTITUTION:A couple of bending rolls 3 and 4 which are accessible to the shaft of fixed center roll 1 via a moving cylinder and movable in a circular direction centering the center roll 1 through an angle adjusting cylinder are provided. When a metallic pipe P is passed plural times between the center roll 1 and the bending rolls 3 and 4 to be bent with a specific radius of curvature, the moving cylinder and angle adjusting cylinder are synchronously operated each time and the length D of the metallic pipe P between the bending rolls 3 and 4 is fixed. Thus, the bending is simply and beautifully executed without requiring any skillfulness of an operator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll bending method using a roll bender for bending a metal pipe or a profile.

[0002]

2. Description of the Related Art As shown in FIG. 20, when bending a metal pipe, for example, a center roll (40) is movable in the direction of arrow A with respect to two bending rolls (41) and (42). It is said that. Then, while passing the pipe (43) between the center roll (40) and the two bending rolls (41) and (42), the center roll (40) is moved in the direction of arrow A to perform bending work to a predetermined curvature. It is a thing.

[0003]

In the roll bending described above,
When bending one pipe (43) to a predetermined curvature while moving the center roll (40) in the direction of arrow A, the curvature of the pipe (43) gradually increases. Therefore, the arc length of the pipe (43) between the bending rolls (41) and (42) becomes long,
Since the roll load applied to each roll also changes with this, in order to bend the pipe (43) beautifully to a desired curvature,
There is a problem that a certain degree of skill of the operator is required.

Further, in particular, when a straight pipe portion having a constant length is provided at both ends of the pipe (43), the pipe is constricted at the boundary between the straight pipe portion and the bent portion, or the bent portion of the pipe is bent. There is a problem that wrinkles are likely to occur inside.

Therefore, the bending process of this kind of pipe is
The work efficiency is low, for example, a skilled worker is forced to perform it, and one worker is always required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a roll bending method in which bending work can be performed easily and beautifully without damaging a pipe, a profile or the like, and requiring no skill of an operator.

[0007]

SUMMARY OF THE INVENTION A first roll bending method of the present invention is a fixed center roll and two bending rolls that are movable to the center roll and movable to the left and right of the center roll. When the bending work is performed through the work, the bending work is performed while keeping the work length between the bending rolls constant.

A second roll bending method of the present invention is a method of bending a roll between two bending rolls which are respectively movable to the left and right sides and a center roll which is freely accessible to the bending roll. The bending work is carried out while keeping the work length constant.

The third roll bending method of the present invention is
Only the middle part of the work is bent through the work between the fixed center roll and two bending rolls that can move to the center roll and move to the left and right sides of the center roll respectively. When leaving, the front end of the linear portion on the rear end side of the work to be supplied comes into contact with the bending roll on the work supply side, and at the same time, the bending roll on the work supply side is separated from the center roll.

[0010]

Of the roll bending methods of the present invention described above, the first
In the second method, the work length between the two bending rolls is always constant, so that the bending work can be performed with a substantially constant load without changing the roll load of the two bending rolls that bend the work. Further, the work position between the two bending rolls can be easily grasped.

According to the third roll bending method of the present invention, since the bending roll is moved away from the center roll, no roll load is applied to the linear portion at the end of the work, so that the curved portion and the straight portion are accurately formed on the work. To be done.

[0012]

EXAMPLE Next, an example in which the roll bending method of the present invention is carried out by using a roll bender having a pyramid shape shown in the drawings will be described.

In the present specification, front and rear, left and right, and upper and lower are based on FIG. 1, the front means the lower side of FIG. 1, the rear means the upper side of the same figure, the left means the left side of FIG. 1, and the right side. Means the right side of the figure, the upper side means the front side of the drawing sheet of FIG. 1, and the lower side means the back side.

The roll bender used in this embodiment includes a rotatable center roll shaft (1a) vertically supported by a bender body (8) and a center roll (1a) mounted on the center roll shaft (1a). ), Two box-shaped holders (2) whose one end is supported by the center roll shaft (1a) and swings horizontally, and each holder (2) is movable toward the center roll shaft (1a). A base (10) that is held and rotatably supports the bending roll shafts (3a) (4a), and is mounted on the upper part of each bending roll shaft (3a) (4a) at the same height as the center roll (1) 2 One bending roll (3) (4) and moving cylinder to move each base (10)
Angle adjustment cylinder that swings (5) and each holder (2)
The bending rolls (3) and (4) can be brought close to the center roll (1) by the operation of the moving cylinder (5) and the center roll (1) by the operation of the angle adjusting cylinder (6). ) Centering on each bending roll (3) (4)
Are said to be movable.

As shown in FIG. 4, the center roll shaft (1a) has two bearing parts (8) provided on the front surface of the bender body (8).
It is rotatably supported by (a) and (8b), and the left and right holders (2)
Have mounting portions (2a) and (2b) projecting from the upper and lower portions of the center roll shaft (1a) respectively, and these mounting portions (2a) and (2b)
By inserting the center roll shaft (1a) vertically, the two holders (2) can swing.

The left and right moving cylinders (5) are fixed to the end surface of the holder (2) opposite to the center roll shaft (1a), and the tip of the rod (5a) of the moving cylinder (5) is the side surface of the base (10). Are linked to. Guide plate on the bottom of each holder (2)
(7) are provided respectively.

The angle adjusting cylinder (6) is rotatably mounted on the bender body (8) by a pin (6b) as shown in FIG. 2, and the tip of the rod (6a) is connected to the holder (2). ing.

The above-mentioned moving cylinder (5) and angle adjusting cylinder (6) are operated by the numerical control described below according to the desired bending of the pipe or the profile.

The center roll (1) and the bending roll (3)
(4) are center roll axis (1a) and bending roll axis (3
a) Each is driven by a motor (not shown) at the lower end of (4a). A guide piece (13) having a guide roll (13a) at its tip is provided on the roll bender main body (8) so as to face the holding portion (9c) of the pipe.

When bending a pipe by the roll bender of the embodiment, as shown in FIG.
(1) and the left and right bending rolls (3) (4) rotate and the pipe (P)
Is interposed between the center roll (1) and the left and right bending rolls (3) (4). At this time, operate the left and right moving cylinders (5) to extend the rods (5a) and move the base (10) to the center roll shaft.
Double bending rolls by moving to (1a) side (3) (4)
Simultaneously approach the center roll (1) and press the pipe (P) against the center roll (1), so that the pipe (P) is bent backward around the contact position with the center roll (1).

Further, in synchronization with the operation of the both bending rolls (3) and (4), the two angle adjusting cylinders (6) are respectively actuated to contract the rods (6a) thereof, so that each holder
Bending rolls (3) as a result of each (2) swinging backwards
(4) moves left and right around the center roll (1). Therefore, the pipe (P) is bent so as to be wound around the center roll (1).

In this case, the angle adjusting cylinder (6)
If only one of them is operated, only one end of the pipe (P) will be bent. Therefore, asymmetric bending of the pipe can be performed.

Next, bending rolls (3) (4) when the pipe (P) described in the above embodiment is bent symmetrically as a work
The specific control of will be described.

Usually, when bending the pipe (P) to a predetermined curvature, the pipe (P) is passed between the rolls a plurality of times and the bending rolls (3) (4) are moved to the center roll (1) side each time. And finally processed into a predetermined curvature. At this time, the length of the pipe (P) between the bending rolls (3) and (4) (hereinafter, “work length
(D)), when the rod (5a) of the moving cylinder (5) is extended and the bending rolls (3) (4) are brought close to the center roll (1), the bending rolls (3) (4) As a result of approaching each other,
The work length (D) between both bending rolls is shortened (see Fig. 6). In addition, when the rods (6a) of the angle adjustment cylinder (6) are contracted and the bending rolls (3) (4) are moved to the left and right sides of the center roll (1), the space between both bending rolls (3) (4) is reduced. On the contrary, the work length (D) at becomes longer (see Fig. 7).

In the present invention, the moving cylinder (5)
And bending roll (3) by actuation of the angle adjustment cylinder (6)
By performing the two movement patterns of (4) in conjunction with each other, the pipe (P) is rolled and bent while the work length (D) is always constant.

If the work length (D) is varied without being constant, in this kind of roll bending, the pipe (P)
The timing at which the sheet moves out of each bending roll (3) (4) also changes. Therefore, for example, a pipe to be bent
When a certain straight part (S) is left on both ends of (P), it becomes difficult to form the bent part (C) and the straight part (S) accurately, and the bending rolls (3) (4) are bent. The load also fluctuates as the work length (D) changes. FIG. 8 shows the relationship between the movement amount of the bending roll and the position of the work in contact with the center roll in the left-right symmetrical bending.

Therefore, when the pipe (P) is passed between the rolls a plurality of times and finally bent to a predetermined curvature, the moving cylinder (5) and the angle adjusting cylinder (6) are operated synchronously for each pass. Thus, the bending rolls (3) and (4) are interlocked with the above-mentioned two operation patterns to make the work length (D) constant.

The positions of the bending rolls (3) and (4) for keeping the work length (D) constant for each pass are given by the following general formula.

[0029]

[Equation 1] Each symbol in the above formula is as shown in FIG.

L: Distance between centers of bending rolls (3) (4) H: Distance between centers of bending rolls (3) (4) and center roll (1) R1: Radius Rc of bending rolls (3) (4) : Radius of the center roll (1) r: radius of curvature of the work in each pass w: outer diameter of the work Also, maintain the positional relationship between the center roll (1) and the bending rolls (3) (4) obtained by the above formula The bending roll position (x) and the bending roll angle (θ) are obtained by the following relational expressions. The bending roll position (x) and the bending roll angle (θ) are as shown in FIG. 9.

[0031]

[Equation 2] For example, when a carport profile material is passed between rolls multiple times and finally bent to 400R, the bending roll position (x) is calculated using the above formula in order to keep the work length (D) constant in each pass. ) And the bending roll angle (θ) are shown in FIGS. 10 and 11. Also, in this case, the center distance (L) of the bending rolls (3) (4) and the bending rolls (3) (4)
The center distance (H) between the center roll (1) and the center roll (1) is as shown in FIG.

On the other hand, when the bending roll position (x) and the bending roll angle (θ) are constant, the arc length (D) of the work is obtained by the following formula.

[0033]

[Equation 3] Next, the change in the work length (D) when roll-forming the carport profile 400R using the above formula is shown in FIG.
This is as shown in FIG. Figure 13 shows work between rolls
While moving (W) forward and backward repeatedly, move cylinder (5)
This is a case where the bending rolls (3) and (4) are brought close to the center roll (1) by activating (see FIG. 6). At this time, the angle adjusting cylinder (6) is not operated and the bending roll angle (θ) is set to 25
I fixed it every time. On the other hand, FIG. 14 shows work between rolls.
While repeating (W) forward and backward movement, angle adjustment cylinder
This is a case where the bending rolls (3) and (4) are moved backward by contracting (6) (see FIG. 7). At this time, the moving cylinder (5) was not operated, and the bending roll position (x) was 386.18 mm.
Fixed to.

The calculation formula of the work arc length (D) described above is derived as follows. As shown in FIG.
A right triangle (A) consisting of the center (C) of the radius of curvature (r) of (W), the axis (B) of the bending rolls (3) (4), and the midpoint (A) of the bending rolls (3) (4). ) (B) (C)

[Equation 4] Substituting the above equation into the relational expression of sin ² x + cos ² x = 1,

[Equation 5] Further, the above equations of the bending roll position (x) and the bending roll angle (θ) are also calculated from the above right triangles (A) (B) (C) by H = xcos θ ..... L = 2xsin θ .. Is substituted into the relational expression of sin ² x + cos ² x = 1,

[Equation 6] As shown in FIG. 15, the front end of the straight part (S) of the work (W) is applied to the bending roll (4), and at the same time as the straight part (S) is left, as shown in FIG. ) Away from the center roll (1). Therefore, the operation of contracting the rod (5a) of the moving cylinder (5) is performed. In this case, the other bending roll (3) is not moved. This is because it requires less movement (rotation) of the entire work (W). And the straight part on the other end side of the work (W)
When the front end of (S) contacts the bending roll (3), contrary to the above, the bending roll (3) is once moved away from the center roll (1), and the bending roll (4) is left as it is. That is, only the bending roll on which the straight part (S) of the work (W) approaches is temporarily moved away from the center roll (1) for each pass.

Displacement of the bending rolls (3) and (4) and the center roll (1) when moving only one of the bending rolls described above
The relation of the position of the work (W) in contact with is as shown in FIG. In addition, both bending rolls (3) (4) are center rolls.
When it is symmetrically moved away from (1), it becomes as shown in FIG.

In the above embodiment, when the center roll (1) is fixed and the two bending rolls (3) and (4) are approached to the center roll (1) and wrap around the left and right sides of the center roll (1). However, the present invention is not limited to this. In the present invention, as shown in FIG. 19, between the two bending rolls (23) and (24) that are respectively movable to the left and right sides, and the center roll (21) that is accessible to the bending rolls (23) and (24). When performing bending through the workpiece (W), the work length between the bending rolls (23) and (24)
Bending may be performed while keeping (D) constant.

[0037]

According to the roll bending method of the present invention, since the roll bending can be performed with the loads of the two bending rolls being substantially constant, the pipe or the profile material to be processed can be processed even if the operator does not have some skill. It can be bent without strain.

Further, according to the method of the present invention in which the bending roll is moved away from the center roll at the time when the end of the work is approaching when leaving the straight portion at the end of the work, for example, in the case where the work is a pipe, at the end of the work. The occurrence of constriction is prevented, and smooth processing from a curved portion to a straight portion can be easily performed. Moreover, when used in combination with the method of the first aspect of the present invention, in combination with accurate grasping of the work position by making the work length constant between the bending rolls, bending work that leaves a straight part at the end of the work is more beautiful. It can be done.

[Brief description of drawings]

FIG. 1 is an enlarged plan view showing a main part of a roll bender used in the present invention.

FIG. 2 is a plan view of a roll bender used in the present invention.

FIG. 3 is a front view of a roll bender used in the present invention.

FIG. 4 is a front view showing a roll bender used in the present invention with a part thereof cut away.

FIG. 5 is a partial sectional view showing a mounting structure of a bending roll in a roll bender used in the present invention.

FIG. 6 is a plan view showing the operation of the bending roll.

FIG. 7 is a plan view showing another operation of the bending roll.

FIG. 8 is a graph showing movement of a bending roll.

FIG. 9 is a plan view showing a positional relationship between each roll and a work.

FIG. 10 is a graph showing changes in bending roll position.

FIG. 11 is a graph showing changes in bending roll angle.

FIG. 12 is a graph showing changes in roll spacing.

FIG. 13 is a graph showing changes in arc length between rolls.

FIG. 14 is a graph showing changes in arc length between rolls.

FIG. 15 is a plan view showing a state where a work end portion is in contact with a bending roll.

FIG. 16 is a plan view showing a contact state of a work end portion with a bending roll.

FIG. 17 is a graph showing movement of a bending roll.

FIG. 18 is a graph showing movement of a bending roll.

FIG. 19 is a plan view showing another roll bending method of the present invention.

FIG. 20 is a plan view showing a conventional example.

[Explanation of symbols]

 (1) Center roll (1a) Center roll shaft (3) (4) Bending roll (3a) (4a) Bending roll shaft (5) Moving cylinder (6) Angle adjusting cylinder (8) Vendor body (10) Base (D ) Work arc length (S) Straight part (W) Work

Claims (3)

[Claims] 1. A fixed center roll (1) and two bending rolls (3) which can be moved toward the center roll (1) and can be moved to the left and right sides of the center roll (1) respectively.
(4) When bending the workpiece (W) through the
A roll bending method characterized by performing bending while keeping the work length (D) between the bending rolls (3) and (4) constant. 2. A work (W) is passed between two bending rolls (23) (24) which are respectively movable to the left and right sides and a center roll (21) which is accessible to the bending rolls (23) (24). When performing bending, a roll bending method is characterized in that the bending is performed while keeping the work length (D) between the bending rolls (23) and (24) constant. 3. A fixed center roll (1) and two bending rolls (3) which are movable toward the center roll (1) and are movable to the left and right sides of the center roll (1) respectively.
(4) Bending only the middle part of the work (W) through the work (W) between them, and leaving the straight part (S) at the end of the work (W), the rear end side of the supplied work (W) A roll bending method characterized in that the front end of the straight portion (S) contacts the bending roll on the work supply side and at the same time the bending roll on the work supply side is moved away from the center roll (1).