JP2614807B2 - Method and apparatus for manufacturing bent pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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.
Cut off at an angle of 45 ° from a to form an intermediate processed material 52.
The cutting direction is such that after bending, the inner equivalent portion 53 is
2, the outer equivalent portion 54 after bending becomes the longer side in the longitudinal direction of the intermediate processed material 52, and the longitudinal direction of the intermediate processed material 52 is made symmetrical in the figure. The cross section of the intermediate processed material 52 is a hollow circle. The intermediate workpiece 52 thus formed is bent by a bending machine such that the inner corresponding portion 53 after bending is located inside. At this time, a core metal is used because the bending radius is usually small. FIG. 11 shows the bent tube W thus formed.
1 is a side view, opposite end surfaces 55 of the curved tube W1 are orthogonal, the inner portion 56 to the position of radius R ₁ centered on the intersection O,
The outer portion 57 exists at the position of radius R _2. Among these, the cross section of the bent pipe W1 cut by a plane passing through the intersection O is circular.
Similarly, a bent pipe W2 having short straight pipe portions 58 at both ends shown in FIG. 12 can be theoretically processed from an intermediate processed material 62 similar to FIG. 13 as shown in FIG. Not realized. Fig. 1
Cut one end 63 of the straight pipe obliquely as shown at 5 and 16
It is sufficient if the bent pipes W1 and W2 can be manufactured by bending and bending, but it is impossible at present because the movement of the meat portion is impossible.

[0003]

In the method for manufacturing a bent pipe as described above, the movement of the meat in the bending process is complicated, and it is difficult to finish the thickness uniformly. In addition, a straight pipe is welded to an end of the bent pipe. The shape of such a bent pipe is defined as Japanese Industrial Standard (JIS). In recent years, as the quality of pipe welding has become more sophisticated and the shortage of construction technicians has become more severe, this construction is changing from human hands to the era of automatic welding using computers. In order to meet this need, there are many aspects in which the conventional shape set in the JIS standard and the welding joint are not suitable for automatic welding. The automatic welding of the bent pipe W1 has the following problems.

FIG. 17 shows a method of automatically welding a straight pipe SW to the bent pipe W1 of FIG. The bent pipe W1 and the straight pipe SW have their end faces abutting each other, the straight pipe SW is fixed with a fixing tool 63, and the bent pipe W1 is fixed with a fixing tool (not shown). In the welding, the welding electrode F is rotated around the welded portion 64 to perform automatic welding. With this method, it is difficult to fix the bent tube W1 because the bent portion must be fixed. Even if the bent tubes have the same diameter, the radius must be adjusted each time the radius of the bent tube is different. Fixtures need to be changed. In welding a titanium alloy pipe or the like, it is preferable to block the weld 64 from the atmosphere, but it is difficult to provide a member that completely blocks the weld 64 from the atmosphere. This difficulty is particularly great when welding bent pipes. Therefore, it is desirable that both the bent pipes W1 and W2 can be obtained as a method and a device for manufacturing the bent pipe.

[0005] The intermediate workpiece 52 is formed by cutting off a part 65 of the end portion, but this is a waste of material.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for manufacturing a bent pipe in which the thickness of each part is easily obtained without wasting material. It is another object of the present invention to provide a method and an apparatus for manufacturing a bent tube and another tube, which facilitate automatic welding of the bent tube and the other tube.

[0007]

Means for Solving the Problems The first invention of the present invention is the second invention.
A straight pipe for manufacturing a bent pipe having a length corresponding to the entire length of the two bent pipes is used as a material. Bending rolls are arranged on different sides of both ends of the straight pipe end, 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 to the center of the straight pipe in parallel with the straight pipe,
This is a method for manufacturing a bent pipe in which the straight pipe is bent into an S-shape to form an S-shaped pipe, and the S-shaped pipe is divided into two to obtain two bent pipes.

According to a second aspect of the present invention, there is provided a track and two slides moving in opposite directions in parallel on the track, and a bending roll shaft in a direction perpendicular to a plane including both slides is attached to each slide. A bending roll having an arc-shaped cross-section groove which is rotatable around the shaft and in which the straight pipe of the workpiece is fitted on the outer periphery is arranged, and the semicircles on the opposite sides of the straight pipe are arranged in the grooves of both bending rolls. A clamping device that can be fitted and pressable in the vicinity of the position at which the bending roll and the workpiece start contacting is rotatably provided on the bending roll shaft, and sends the two slides in opposite directions to each other, and connects each of the clamping devices to the bending roll. This is a bending pipe manufacturing apparatus provided with an interlocking drive device that rotates in the same direction about an axis.

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.

Embodiment 1 FIG. 1 shows a plan view. Slides 2a, 2 are provided on the tracks 1a, 1b which are arranged and fixed in parallel.
b is movably fitted. Hydraulic cylinders 3a and 3b are provided as drive means for moving the slides 2a and 2b in the opposite directions at the same speed. Hydraulic cylinder 3
A and 3b are guaranteed to move at the same speed and in opposite directions by a synchronization means not shown in FIG. On the slides 2a and 2b, bending roll shafts 4a and 4b are implanted orthogonally 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 shown in FIG. 1 is mounted.

Accordingly, 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 connected to the bending rolls 5a and 5b.
Is fitted in the semicircular groove on the outer periphery of. The workpiece W is a hollow cylindrical straight pipe having a length approximately twice the length of the bent pipe to be obtained. The workpiece W is disposed parallel to the tracks 1a and 1b, but may be non-parallel. However, the intersection P of a straight line 8 passing through the center of both bending rolls 5a and 5b and being orthogonal to the tracks 1a and 1b and being at the same distance from the straight lines 6a and 6b and a straight line 9 being parallel to and at the same distance from both tracks 1a and 1b. The workpiece W needs to be arranged symmetrically with respect to. Both ends of the workpiece W are pressed and fixed by the clamp devices 11a and 11b. The clamp device includes receiving members 13a, 13b fixed to the bending rolls 5a, 5b, and pressers 14a, 14b opposed to the receiving members 13a, 13b and pressing a semicircle of the workpiece W on the side opposite to the bending roll. Is provided.

[0013] As shown in FIG.
Gears 15a and 15b are coaxially fixed to the rack teeth 16a and 15b.
6a and 16b, respectively. These gears 15a, 1
The pitch diameter of 5b is selected so that the bending rolls 5a and 5b roll less with respect to the workpiece W.

As shown in FIG. 4, lined collet chucks 17a and 17b are inserted at both ends of the workpiece W, and are pulled and clamped by the clamp cylinders 22a and 22b via the draw bar 21. Lining collet chuck 1
Reference numerals 7a and 17b denote hydraulic cylinders 19 provided on receivers 13a and 13b fixed to bending rolls 5a and 5b.
a, 19b are provided at the ends of the ram. The drawbar 21
Are 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 section on both sides, and a cutting tool for cutting an S-shaped pipe to be twice as long as the total length of a common product pipe when having a short straight pipe section. It will be the length plus the width.

As shown in FIG. 1, the workpiece W is gripped at both ends by clamping devices 11a and 11b. When gripped, the center line of the presser feet 14a, 14b pressing the workpiece 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 at both ends of the workpiece W, and the clamp cylinders 22a and 22b are urged to fix the collet chucks 17a and 17b at both ends of the workpiece W. Then, the oil cylinders 19a and 19b are urged in the direction in which the ram is retracted to apply a tensile force to the workpiece W.

When the hydraulic cylinders 3a, 3b connected to the slides 2a, 2b are urged in the directions D, D ', the slide 2
Since a and 2b move in the same direction, bending rolls 5a and 5b also move in the same direction. Bending roll 5
Since the gears 15a and 15b fixed to the gears a and 5b are engaged with the rack 16, they rotate in the directions of arrows E and E ', respectively. A presser foot 14a, 14b rotating in the same direction together with the bending rolls 5a, 5b successively moves the workpiece W from both ends toward the center. Bend along 5b. The hydraulic cylinders 19a, 19b are provided with
It rotates with 3b.

As shown in FIG. 5, the movement of the meat of the workpiece W is such that the center line 8 perpendicular to the pipe axis (refer to FIG. 1) moves angularly as the bending proceeds as described above. In other words, the surface flesh moves according to the bending angle of the intermediate product serving as the S-shaped tube.

This will be described with reference to FIG. 10.
Are parallel to each other, and assuming that the radius of the center line 43 of the bent portion 42 centered on the center O ₁ or O ₂ is R and the radius of the bent tube is r, the radius of the outside 44 of the bent portion = R + r inside The radius of 45 = R−r.

Here, a line O ₁ rising from the line connecting the center points O ₁ and O ₂ of the radii of the respective bends by θ around 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 L ₀ = L ₁ always holds when θ + (R−r) θ = 2Rθ. From this, θ = π / 2
For (90 °) at the pipe full length, which proves that equal length of the outer peripheral portion length and the center line, A line O ₁ O
Line O ₁ P rising from the reference by θ with reference to ₂
L ₀ = L ₁ always exists between ₁ and the line O ₂ P ₂ falling by θ from the reference. Similarly, outer radius R
2, when obtaining a radius R the length of the inflection portion of the bus 46 at the position (x) L (x) from the center O ₁ and an inner radius R1 L
(X) = L ₀ . In other words, even if the workpiece W of the straight pipe becomes the intermediate workpiece WS of the S-shaped pipe, the generatrix on the surface of the pipe is the same length at any position around the pipe of the S-shaped pipe, and as described above. Thus, in the bending process, there is no expansion or contraction of the bus bar, so there is no expansion or compression of the meat, and therefore there is no movement of the meat in the direction perpendicular to the axis, so there is no change in the thickness in the bent pipe. Since the deformation from the straight pipe to the bent pipe is caused only by the displacement between the axes as shown in FIG. 5, there is no change in the wall thickness during molding. Thus, when the two bending rolls 5a and 5b approach each other, an intermediate material WS of an S-shaped tube is completed as shown in FIG. Here, the presser feet 14a and 14b are slightly opened and slides 2a and
When the hydraulic cylinders 3a and 3b for driving the cylinder 2b are slightly retracted, the slides 2a and 2b are also slightly retracted.
Both bending rolls 5a and 5b are S-shaped intermediate material WS
Move away from At this position, the presser feet 14a and 14b are opened to take out the intermediate material WS of the S-shaped tube.

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

In the above embodiment, the collet chucks 17a, 17
7b are fixed to both ends of the workpiece W and the hydraulic cylinders 19a,
Although the 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 the high-pressure liquid is provided in the plugs closed at both ends. Alternatively, the high-pressure liquid may be sent into the workpiece W to apply an internal pressure to the workpiece W. Alternatively, bending can be performed by inserting a cored bar.

Embodiment 2 In Embodiment 1, the hydraulic cylinder was used to move the bending roll while rotating it. In this embodiment, the bending roll was 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 the speed reducers 26a, 26b having worms 25a, 25b at their output ends that mesh with the worm wheels 24a, 24b coaxially fixed to the bending rolls 5a, 5b are connected to motors 27a, 27b. This reducer 26
a, 26b are fixed to the slides 2a, 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, the speed is reduced by the speed reducers 26a and 26b to rotate the worms 25a and 25b.
It rotates in the direction of E '. Then bending roll 5
The gears 15a and 15b shown in FIG. 3 fixed to the gears a and 5b rotate in the direction of the arrow and mesh with the rack teeth 16a and 16b and move to the center in the longitudinal direction of the rack 16, so that the bending rolls 5a and 5b move together. 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 tube 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 embodiments, the clamping device is fixed to the bending roll, but FIG. 8 shows that the clamping device is rotatable about the bending roll axis and the rotation of the bending roll and the clamping device is driven by separate driving devices. As shown in FIG.
a, 11b, the bending rolls 5a, 5b are stopped, and the clamping devices 11a, 11b are
The workpiece W is rotated in the direction F 'to bend the end side of the workpiece W, and then the clamping devices 11a and 11b and the bending rolls 5a and 5b are rotated in the same direction at the same angular speed, and the bending rolls 5a and 5b are Move toward the center in the longitudinal direction.

In order to perform such an operation, the receiving holes 13a and 13b of the clamping devices 11a and 11b are respectively provided with arc-shaped long holes 2 around the bending roll shafts 4a and 4b.
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
b from the position in the figure where one end of each of the arc-shaped long holes 28a and 28b is in contact with the receiving ends 13a and 13b in the directions of arrows F and F '.
When rotated 5 degrees, the other ends of the arc-shaped long holes 28a and 28b hit the stop pins 29a and 29b. As shown in FIG. 9, while only the clamp devices 11a and 11b are rotated by 45 degrees, a lock provided so as to be able to enter and leave the tooth grooves (tooth valleys) of the gears 15a and 15b meshing with the rack teeth 16a and 16b. The members 31a and 31b are fitted into 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).
a, 31b provided at the end of the ram with a lock cylinder 32a, 3
2b is urged in the retreating direction to lock members 31a and 31b.
Are separated from the gears 15a and 15b. Therefore, when the clamp devices 11a and 11b first rotate 45 degrees, and then rotate 45 degrees, the clamp devices 11a and 11b rotate.
11b and the bending rolls 5a and 5b rotate integrally. The subsequent rotation forms an inflection portion that becomes an S-shaped tube.

According to this embodiment, the clamping devices 11a,
Since the end of the workpiece W is bent by the rotation of 11b, the pressers 14a, 14b of the clamp devices 11a, 11b are bent.
Even if 14b is turned to a position near the end of the workpiece W,
In the latter half of the bending action, both ends of the workpiece W are bent and are along the bending rolls 5a, 5b, so that the presser foot 1
The pressing force of 4a and 14b may be small, and is suitable for manufacturing a bent pipe W1 having no straight pipe section at both ends.

[0030]

According to the method for manufacturing a bent pipe according to the first aspect of the present invention, one straight pipe corresponding to two bent pipes is used as a workpiece.
Since it is bent by the bending roll in the shape of a letter, the movement of the meat accompanying the bending is performed without difficulty, and a bent pipe having the same thickness can be obtained. Further, since the bending force applied to the workpiece is symmetrically applied, it is not necessary to fix the workpiece to stop the movement.
Furthermore, two bent tubes are produced with less waste of material.

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

According to the third aspect of the present invention, since the bending roll and the clamp device are fixed in the second aspect, the structure is simple and the driving device is also simple.

[Brief description of the 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 bending roll synchronization device parallel to the paper surface of FIG. 1;

FIG. 4 is a horizontal sectional view of a device for applying a tensile force to a workpiece.

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 a second embodiment.

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

9 shows a view parallel to the plane of the paper of FIG. 8 and is a plan view of the bending roll synchronization device.

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

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

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

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

14 is a side view of an intermediate member that can be considered from a conventional example in the method for manufacturing the bent pipe of FIG. 12;

FIG. 15 is a side view of an intermediate material for manufacturing a bent tube that can use materials without waste.

FIG. 16 is a side view of an intermediate material for manufacturing a bent tube that can use materials without waste.

FIG. 17 is a longitudinal sectional view showing a method of 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 work material (S-shaped tube)

Claims (3)

(57) [Claims] 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 formed. The straight pipe is bent in an S-shape by pressing the straight pipe toward the outer periphery of the bending roll and moving the bending roll to the center of the straight pipe in parallel with the straight pipe with a clamp device that rotates about the center. S-shaped tube,
A method for manufacturing a bent pipe in which an S-shaped pipe is bisected to obtain two bent pipes. 2. A track and two slides moving in opposite directions in parallel on the track, and a bending roll shaft in a direction perpendicular to a plane including both slides is attached to each slide, and the slides are used by the shafts. A bending roll having a circular arc-shaped cross section in which a straight pipe of a workpiece is rotatable and fitted on the outer periphery is disposed, and semicircles on opposite sides of the straight pipe are fitted in grooves of both bending rolls, and a bending roll is formed. A clamping device capable of pressing the vicinity of the position where the contact between the workpiece and the workpiece starts is provided rotatably on the bending roll shaft, and the two slides are sent in opposite directions to each other, and the clamping devices are moved in the same direction about the bending roll axis. Bending tube manufacturing device provided with an interlocking drive device for rotating the tube. 3. The bending pipe manufacturing apparatus according to claim 2, wherein the bending roll and the clamp device are integrally fixed.