JPH06234021A - Production method and device of bent tube - Google Patents

Abstract

PURPOSE:To obtain a tube of uniform wall without generating excess material and without forcibly moving a mass by pressing a straight tube toward an outer circumference of a bending roll, and together moving the bending roll parallel with the straight tube to a center of the straight tube. CONSTITUTION:Bending rolls, 5a, 5b are positioned on different sides of both ends of a work W (material), and the work W is fixed with clamping devices 11a, 11b preparing to the bending rolls 5a, 5b. When hydraulic cylinders 3a, 3b are energized to D, D' directions, the bending rolls 5a, 5b move to the D, D' directions while rotating to E, E' directions with a synchronous device, the clamping devices 11a, 11b rotate to the E, E' directions and the work W is bent in an S shape. This obtained S shaped tube is an intermediate material, and two bent tubes are obtained by cutting a point of inflection of the S shaped tube orthogonally to the tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bent pipe manufacturing method and manufacturing apparatus.

[0002]

2. Description of the Related Art A conventional method for manufacturing a bent pipe and a bent pipe manufactured by the manufacturing method will be described with reference to the drawings.
As shown in FIG. 13, connect both end portions 51 of the straight pipe portion placed horizontally to the center line 29.
An intermediate processed material 52 is made by cutting off at an angle of 45 ° from a.
In this cutting direction, after bending, the portion 53 corresponding to the inside is the intermediate processed material 5
2 becomes shorter in the longitudinal direction, and the outer side corresponding portion 54 after bending becomes the side that becomes longer in the longitudinal direction of the intermediate processed material 52, and the longitudinal direction of the intermediate processed material 52 is symmetrical in the drawing. The cross section of the intermediate processed material 52 is a hollow circle. The thus-prepared intermediate processed material 52 is bent by a bending machine so that the inside corresponding portion 53 after bending is located inside. At this time, a core metal is usually used because the bending radius is small. Figure 11 shows the bent pipe W
1 is a side view of FIG. 1 in which both end surfaces 55 of the bent pipe W1 are orthogonal to each other, and an inner portion 56 is located at a position of a radius R _{1 about} an intersection O thereof
The outer portion 57 exists at the position of the radius R ₂ . Among them, the cross section of the bent pipe W1 cut by a plane passing through the intersection O is circular.
Similarly, the curved pipe W2 having short straight pipe portions 58 at both ends shown in FIG. 12 can theoretically be machined from an intermediate processed material 62 similar to that shown in FIG. 13 as shown in FIG. Not realized. In addition, in order to avoid waste of material,
Cut one end 63 of the straight pipe diagonally 64
It is sufficient if the bent pipes W1 and W2 can be manufactured by bending and then, but it is not possible because the movement of the meat portion is impossible.

[0003]

In the method of manufacturing a bent pipe as described above, movement of the meat in the bending process is complicated and it is difficult to finish the wall thickness uniformly. A straight pipe is welded to the end of the bent pipe for use. The shape of such a bent pipe is defined as the Japanese Industrial Standard (JIS). In recent years, as the quality of pipe welding becomes more sophisticated and the shortage of construction engineers becomes more and more serious, this construction is shifting from human hands to the age of automatic welding using computers. In order to meet this need, there are many surfaces that are not adapted to the construction of automatic welding with the conventional shape and the welding joint set in the JIS standard. There are the following problems in automatically welding the bent pipe W1.

FIG. 17 shows a method for automatically welding a straight pipe SW to the bent pipe W1 shown in FIG. The curved pipe W1 and the straight pipe SW are abutted at their end faces, the straight pipe SW is fixed by a fixture 63, and the curved pipe W1 is fixed by a fixture not shown. For welding, the welding electrode F is automatically welded by rotating around the welded portion 64. Since it is such a method, it is difficult to fix the bent pipe W1 because the bent portion must be fixed, and even if the bent pipes have the same diameter, the radiuses of the bent pipes are different for each different radius. Fixtures need to be changed. Further, in welding titanium alloy pipes and the like, it is preferable to shield the welded portion 64 from the atmosphere side, but it is difficult to dispose a member that completely shields the welded portion 64 from the atmosphere side. This difficulty is especially great when welding curved pipes. Therefore, it is desirable that both the bent pipes W1 and W2 can be obtained as a bent pipe manufacturing method and manufacturing device.

The intermediate processed material 52 is formed by cutting off a part 65 of the end portion, which is a waste of material.

It is an object of the present invention to provide a manufacturing method and a manufacturing apparatus for a bent pipe in which the material is not wasted and the wall thickness of each portion can be easily obtained. Another object of the present invention is to provide a manufacturing method and a manufacturing apparatus for a bent pipe and another pipe that facilitates automatic welding of the bent pipe and another pipe.

[0007]

The first invention of the present invention is 2
A straight pipe for manufacturing a bent pipe having a length corresponding to the entire length of one bent pipe is used as a material. Bending rolls are arranged on different sides of both ends of the straight pipe, and the bending roll is rotated about the bending roll axis. By pressing the straight pipe toward the outer circumference of the bending roll with a clamp device and moving the bending roll parallel to the straight pipe to the center of the straight pipe,
This is a method of manufacturing a bent pipe in which the straight pipe is bent into an S-shape to form an S-shape pipe, and the S-shape pipe is divided into two to obtain two bent pipes.

According to a second aspect of the present invention, a track and two slides that are parallel to each other and move in opposite directions are provided on the track, and each slide is attached with a bending roll shaft in a direction perpendicular to a plane including both slides. Bending rolls having an arcuate cross-section groove which is rotatable around the shaft and into which a straight pipe of a workpiece is fitted are arranged on the outer periphery, and the semicircles on the opposite sides of the straight pipe are provided in the grooves of both bending rolls. A clamp device that fits and is capable of pressing the vicinity of the beginning of contact between the bending roll and the workpiece is rotatably provided on the bending roll shaft, sends the two slides in opposite directions, and causes each of the clamping devices to bend. The bending pipe manufacturing apparatus is provided with an interlocking drive device that rotates in the same direction around a shaft.

A third aspect of the present invention is the bending pipe manufacturing apparatus according to the second aspect, wherein the bending roll and the clamp device are integrally fixed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a plan view. The slides 2a, 2 are attached to the tracks 1a, 1b which are arranged in parallel and fixed.
b is movably fitted. Hydraulic cylinders 3a and 3b are provided as drive means for moving the slides 2a and 2b at the same speed and in opposite directions. Hydraulic cylinder 3
The a and 3b are guaranteed to move at the same speed and in opposite directions by a synchronization means not shown in FIG. Bending roll shafts 4a and 4b are planted on the slides 2a and 2b so as to be orthogonal to a plane including both tracks 1a and 1b. Bending rolls 5a and 5b are rotatably supported on the bending roll shafts 4a and 4b, respectively.
The bending roll shafts 4a and 4b are farthest apart at different positions in the longitudinal direction of the tracks 1a and 1b when the workpiece W of FIG. 1 is attached.

Therefore, the bending rolls 5a and 5b are arranged at different positions in the longitudinal direction of the tracks 1a and 1b, and both ends of the workpiece W are bent rolls 5a and 5b.
It fits in the semicircular groove on the outer periphery of. The workpiece W is a hollow cylindrical straight pipe having a length approximately twice that of the curved pipe to be obtained. The workpiece W is arranged in parallel with the tracks 1a and 1b, but it is also possible that the workpiece W is not parallel. However, an intersection point P of a straight line 8 passing through the centers of both bending rolls 5a, 5b and at an equal distance from straight lines 6a, 6b orthogonal to the orbits 1a, 1b and a straight line 9 parallel to both orbits 1a, 1b at the same distance. It is necessary that the workpiece W be symmetrically arranged with respect to. Both ends of the workpiece W are pressed and fixed by the clamp devices 11a and 11b. The clamp device is provided with pressers 14a, 14b which are opposed to the receiving metal 13a, 13b fixed to the bending rolls 5a, 5b and the respective receiving metal 13a, 13b and which press the semi-circle of the workpiece W on the anti-bending roll side. Equipped with.

As shown in FIG. 3, the bending roll 5
Gears 15a and 15b are coaxially fixed to a and 5b, and these gears 15a and 15b are rack teeth 1 on both sides of the rack 16.
6a and 16b are in mesh with each other. This gear 15a, 1
The pitch diameter of 5b is selected such that the bending rolls 5a and 5b roll less with the workpiece W and roll.

As shown in FIG. 4, lining collet chucks 17a and 17b are inserted into both ends of the workpiece W, and are pulled and clamped by clamp cylinders 22a and 22b via a draw bar 21. Lined collet chuck 1
7a and 17b are hydraulic cylinders 19 provided on the receiving plates 13a and 13b fixed to the bending rolls 5a and 5b.
They are provided at the ram ends of a and 19b. Drawbar 21
Is inserted through the rams of the hydraulic cylinders 19a and 19b, and the clamp cylinders 22a and 22b are fixed to the rear ends of the rams.

The operation of the above configuration will be described.

The length of the workpiece W is a curved pipe having no short straight pipe portions on both sides, or a short straight pipe portion. A cutting tool for cutting an S-shaped pipe, which will be described later, to twice the total length of the co-product pipe. It will be the length plus the width.

As shown in FIG. 1, the workpiece W is clamped at both ends by the clamp devices 11a and 11b. When gripped, the center line of the presser foot 14a, 14b that presses the work piece is at a position offset by δ from the center of the bending rolls 5a, 5b. The rams of the hydraulic cylinders 19a and 19b are advanced to insert the collet chucks 17a and 17b into both ends of the workpiece W, and the clamp cylinders 22a and 22b are urged to fix the collet chucks 17a and 17b to both ends of the workpiece W. , The oil cylinders 19a and 19b are urged in the direction in which the ram can be retracted, and a tensile force is applied to the workpiece W in advance.

When the hydraulic cylinders 3a and 3b connected to the slides 2a and 2b are biased in the D and D'directions, the slide 2
Since a and 2b move in the same direction, the bending rolls 5a and 5b also move in the same direction. Bending roll 5
Since the gears 15a and 15b fixed to a and 5b mesh with the rack 16, they rotate in the directions of arrows E and E ', respectively. The pressers 14a and 14b that rotate in the same direction as the bending rolls 5a and 5b sequentially bend the workpiece W from both ends toward the center. Bend along 5b. The hydraulic cylinders 19a and 19b are receiving moneys 13a and 1
Rotate with 3b.

As shown in FIG. 5, the movement of the meat of the workpiece W is such that the center line 8 (see FIG. 1) perpendicular to the tube axis moves angularly as the bending progresses. That is, the surface meat moves according to the bending angle of the intermediate product that becomes the S-shaped pipe.

This will be described with reference to FIG. 10. The shape of the S-shaped intermediate processed material WS is as follows.
Are parallel to each other, where R is the radius of the center line 43 of the bent portion 42 centered on the center O ₁ or O ₂ and r is the tube radius of the bent pipe, the radius of the outer side 44 of the bent portion 42 is R + r The radius of 45 = R−r.

Here, a line O _{1 which} rises by θ from the line connecting the center points O ₁ and O ₂ of the respective radii of the bends with O ₁ as the center.
P ₁ and O ₂ by θ around the down line O ₂ P _2, consider the city, the length L ₀ and the length L ₁ of the outer periphery 9 of this period the centerline _{43 L 0 = 2Rθ L 1 =} (R + r ) Θ + (R−r) θ = 2Rθ, and L ₀ = L ₁ is always established. From this, θ = π / 2
In the case of (90 °), it has been proved that the length of the outer peripheral portion and the length of the center line are equal in the entire length of the pipe, and the line O ₁ O
Line O ₁ P that rises by θ from the standard with reference to _{2
Between 0} and the line O ₂ P _{2 which} falls from the reference by θ, L ₀ = L ₁ is always satisfied. Similarly, the outer radius R
2. Assuming that the inner radius is R1, the length L (x) of the generatrix 46 of the inflection portion at the position of the radius R (x) from the center O ₁ is L
(X) = L ₀ . That is, even if the work W of the straight pipe becomes the intermediate work material WS of the S-shaped pipe, the generatrix of the surface of the pipe has the same length at all positions around the pipe of the S-shaped pipe. Similarly, during the bending process, there is no expansion or contraction of the generatrix, so there is no expansion or compression of the meat, so there is no movement of the meat in the direction perpendicular to the axis, so there is no change in wall thickness in the bent pipe. As shown in FIG. 5, the deformation from the straight pipe to the bent pipe is caused only by the displacement between the axes, so that the wall thickness does not change during molding. Thus, when both bending rolls 5a and 5b come close to each other, the intermediate material WS of the S-shaped pipe is completed as shown in FIG. Now open the presser foot 14a, 14b a little and slide 2a,
When the hydraulic cylinders 3a, 3b driving 2b are slightly retracted, the slides 2a, 2b are also slightly retracted,
Both bending rolls 5a and 5b are intermediate material WS of S-shaped tube
Get away from. At this position, the pressers 14a and 14b are opened to take out the intermediate material WS of the S-shaped pipe.

The intermediate material WS of the S-shaped tube is a bent tube W1 or W2.
Is an intermediate product. Here, the intermediate material WS of the S-shaped pipe
When the central inflection point is cut orthogonally to the pipe, two curved pipes W1 or W2 are completed.

In the above embodiment, the collet chucks 17a, 1a
7b are fixed to both ends of the workpiece W, and hydraulic cylinders 19a,
Although a tensile force is applied at 19b, in order to prevent the flattening of the workpiece W during molding, both ends of the workpiece W are closed and an inlet for high pressure liquid is provided in the plugs closed at both ends. Alternatively, the high pressure liquid may be fed into the workpiece W to apply an internal pressure to the workpiece W. Alternatively, the core metal may be inserted to perform bending.

[Embodiment 2] In Embodiment 1, the hydraulic cylinder is used to rotate and move the bending roll, but in this embodiment, the bending roll is directly rotated to obtain the same motion. is there.

FIG. 7 is a plan view of the second embodiment. The input shafts (not shown) of speed reducers 26a, 26b having worms 25a, 25b meshing with worm wheels 24a, 24b coaxially fixed to the bending rolls 5a, 5b are connected to motors 27a, 27b. This reducer 26
a and 26b are fixed to the slides 2a and 2b. The motors 27a and 27b are servo motors that rotate synchronously, and are rotated at a constant speed by a numerical controller (not shown).

When the motors 27a and 27b rotate, they are decelerated by the speed reducers 26a and 26b to rotate the worms 25a and 25b, and the bending rolls 5a and 5b are indicated by arrow E in the drawing.
Rotate in the E'direction. Then bending roll 5
Gears 15a and 15b fixed to a and 5b shown in FIG. 3 rotate in the direction of the arrow and mesh with rack teeth 16a and 16b to move to the center of the rack 16 in the longitudinal direction, so that the bending rolls 5a and 5b also move. Then, the bending roll shafts 4a and 4b move by moving the slides 2a and 2b on the tracks 1a and 1b. Therefore, the S-shaped pipe WS is obtained from the workpiece W as in the previous embodiment.

[Third Embodiment] FIG. 8 shows a third embodiment. In each of the above-described embodiments, the clamp device is fixed to the bending roll, but the clamp device is rotatable about the bending roll shaft, and the bending roll and the clamp device are rotationally driven by separate driving devices, as shown in FIG. The clamping device 11 between the center and the end of the workpiece W
a, 11b to stop the bending rolls 5a and 5b, and the clamp devices 11a and 11b to F,
The workpiece W is rotated in the F'direction to bend the end side of the workpiece W, and then the clamping devices 11a, 11b and the bending rolls 5a, 5b are rotated in the same direction at the same angular velocity, and the bending rolls 5a, 5b are moved toward the workpiece W. Move toward the center in the longitudinal direction.

In order to perform such an operation, the circular arc-shaped elongated holes 2 centering on the bending roll shafts 4a and 4b are formed in the receiving members 13a and 13b of the clamping devices 11a and 11b, respectively.
8a and 28b are provided, and stop pins 29a and 29b fitted in the long holes 28a and 28b are fixed to the bending rolls 5a and 5b. Stop pins 29a, 29
From the position where b is in contact with one end of the arc-shaped elongated holes 28a, 28b, the receiving plates 13a, 13b are 4 in the directions of the arrows F, F '.
The other ends of the arc-shaped elongated holes 28a and 28b come into contact with the stop pins 29a and 29b when rotated by 5 degrees. Then, while only the clamp devices 11a and 11b are rotated by 45 degrees, as shown in FIG. 9, a lock provided so as to be able to move in and out of the tooth grooves (tooth roots) of the gears 15a and 15b meshing with the rack teeth 16a and 16b. The members 31a and 31b are fitted in the tooth spaces, and when the clamp devices 11a and 11b rotate 45 degrees, the position of the clamp devices 11a and 11b is detected by a position detection sensor (not shown).
Lock cylinders 32a, 3 having a, 31b at the ram end
2b is urged in the backward direction to lock members 31a, 31b.
Are separated from the gears 15a and 15b. Therefore, when the clamp devices 11a and 11b rotate 45 degrees first, and then rotate 45 degrees, the clamp devices 11a and 11b rotate.
11b and the bending rolls 5a and 5b rotate integrally. By the subsequent rotation, an inflection portion which becomes an S-shaped tube is formed.

According to this embodiment, the clamp device 11a,
Since the end of the workpiece W is bent by the rotation of 11b, the presser foots 14a of the clamp devices 11a, 11b,
Even if 14b is rotated to a position just near the end of the workpiece W,
In the latter half of the bending action, the presser foot 1 is bent because both ends of the workpiece W are bent and along the bending rolls 5a and 5b.
The pressing force of 4a and 14b is small, and is suitable for manufacturing the bent pipe W1 having no straight pipe portion at both ends.

[0030]

According to the method for manufacturing a bent pipe of the first invention of the present invention, one straight pipe corresponding to two bent pipes is used as a workpiece.
Since the bending roll is bent into a letter shape, the movement of the wall due to the bending process is performed without difficulty, and a bent pipe having the same wall thickness can be obtained. In addition, since the bending force applied to the work piece is symmetrically applied, it is not necessary to fix the work piece to stop the movement of the work piece.
Furthermore, two bent tubes are produced with less material waste.

The bending pipe manufacturing apparatus according to the second aspect of the present invention is provided with two slides which are parallel to each other on the track and move in opposite directions, and both slides are rotatably attached with bending rolls. Since the workpiece is pressed and bent with a clamp device that is coaxial with the roll,
Since the force applied to the entire device is symmetrical and the elastic deformation of each part also occurs symmetrically, it can be bent as a bending machine that requires a large bending force without increasing the rigidity. Can be small.

The third aspect of the present invention is the same as the second aspect of the present invention, but since the bending roll and the clamp device are fixed, the structure is simple and the drive device is simple.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of the present invention.

FIG. 2 is a partial side view of FIG.

FIG. 3 is a plan view of a synchronizing device for a bending roll parallel to the paper surface of FIG.

FIG. 4 is a horizontal cross-sectional view of an apparatus for applying a tensile force to a work piece.

FIG. 5 is a plan view showing movement of meat in the processing method of the present invention.

FIG. 6 is a schematic plan view showing the operation of FIG.

FIG. 7 is a plan view of the second embodiment.

FIG. 8 is a schematic plan view of a third embodiment.

9 is a plan view of a synchronizing device for a bending roll, showing a view parallel to the paper surface of FIG. 8. FIG.

FIG. 10 is a plan view for explaining the movement of the wall to reach the intermediate material in the bent pipe manufacturing method of the present invention.

FIG. 11 is a side view of the bent pipe.

FIG. 12 is a side view of another example of the bent pipe.

FIG. 13 is a side view showing an intermediate member in the method for manufacturing the bent pipe of FIG. 11 in the conventional example.

14 is a side view of an intermediate material that can be considered from a conventional example in the method of manufacturing the bent pipe in FIG.

FIG. 15 is a side view of an intermediate material for manufacturing a bent pipe in which materials can be used without waste.

FIG. 16 is a side view of an intermediate material for manufacturing a bent pipe in which materials can be used without waste.

FIG. 17 is a vertical cross-sectional view showing a method for automatically welding a straight pipe to a bent pipe.

[Explanation of symbols]

 1a, 1b Track 2a, 2b Slide 4a, 4b Bending roll shaft 5a, 5b Bending roll 11a, 11b Clamping device 15a, 15b Gear 16 Rack W Workpiece WS Intermediate processing material (S-shaped pipe)

Claims (3)

[Claims] 1. A straight pipe for manufacturing a bent pipe having a length corresponding to the entire length of two bent pipes is used as a material, and bending rolls are arranged on different sides of both ends of the straight pipe, and a bending roll shaft is provided. The straight pipe is bent into an S-shape by pressing the straight pipe toward the outer circumference of the bending roll with a clamp device that rotates about the center and moving the bending roll to the center of the straight pipe in parallel with the straight pipe. S-shaped tube,
A method for manufacturing a bent pipe, which is obtained by dividing an S-shaped pipe into two parts to obtain two bent pipes. 2. A track and two slides parallel to each other and moving in opposite directions on the track are provided, and each slide is provided with a bending roll shaft perpendicular to a plane including both slides. Bending rolls that are rotatable and have a circular cross-section groove to which a straight pipe of a workpiece is fitted are arranged. Semi-circles on opposite sides of the straight pipe are fitted in the grooves of both bending rolls. And a clamp device capable of pressing near the position where the workpiece starts to contact are rotatably provided on the bending roll shaft, and the two slides are fed in opposite directions, and the respective clamp devices are moved in the same direction around the bending roll shaft. Bending pipe manufacturing device with interlocking drive device to rotate to. 3. The bending pipe manufacturing apparatus according to claim 2, wherein the bending roll and the clamp device are integrally fixed.