JP2002192237A - Bender for pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bender for a pipe for forming an exhaust pipe, in which an exhaust gas can smoothly flow, while a pressure wave hardly reflects on the way. SOLUTION: A high-pressure pump 105 for pressurizing the water in a material pipe 31 is connected with a first plugging means 32 for plugging one end of the material pipe 31 under the pressure corresponding to the curvature radius of the part to be bent in the material pipe 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe bending apparatus for bending an exhaust pipe for connecting a muffler to an engine of a motorcycle, a snowmobile, a four-wheel buggy or the like.

[0002]

2. Description of the Related Art Conventionally, an exhaust pipe for a motorcycle is formed by bending a stainless steel pipe into a predetermined shape. The exhaust pipe of this type desirably has a constant inner diameter so that the exhaust gas can flow smoothly through the pipe and that the pressure wave is not unnecessarily reflected on the way.

[0003] However, when the pipe is bent, the outer portion of the bend is unevenly distributed inward, and the curvature of the outer portion of the bend becomes smaller than that of the inner portion. And the cross-sectional area of the exhaust passage is reduced. Such inconvenience can be solved to some extent by performing a bending process in a state in which the liquid is sealed inside the bent portion, as disclosed in, for example, Japanese Patent Application Laid-Open No. 10-58051.

In the bending apparatus disclosed in this publication, a plug member is inserted into one end and the other end of a bent portion of a pipe to seal the inside of the bent portion and to seal from one plug member. Bending is performed in a state where the liquid is supplied into the space and the liquid is filled in the sealed space. In this bending apparatus, the bending is performed by holding the pipe by a roll die located inside the bend and a clamping die outside the bend, and winding the pipe around the roll die while pressurizing the liquid to a predetermined pressure. ing.

[0005]

However, even when the liquid is pressurized and sealed in a pipe in a pressurized state and the bending process is performed, flattening at the bent portion cannot be prevented. . This is considered to be due to the fact that the pipe extends in the longitudinal direction during bending, the volume in the bent portion increases, and the pressure of the liquid decreases.

For this reason, the exhaust pipe formed by the bending apparatus has an increased exhaust resistance at the bent portion, and the gas exchange performance of the engine becomes low particularly when the engine is in a high rotation range, and the engine has a low gas exchangeability. There is a problem that performance is reduced. Moreover, the cross-sectional area of the passage is minimized at the bent portion, and part of the exhaust pressure wave is reflected here,
The engine performance cannot be improved by effectively utilizing the exhaust pulsation.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and is intended for a pipe forming an exhaust pipe in which exhaust gas can flow smoothly in the pipe and pressure waves are hardly reflected on the way. It is an object to provide a bending device.

[0008]

In order to achieve this object, a pipe bending apparatus according to the present invention comprises a plug means for closing one end of a pipe corresponding to a curvature of a bent portion of the pipe. It is connected to a pressurizing device for pressurizing the liquid in the pipe with a predetermined pressure.

According to the present invention, the pipe is bent in a state where the pressure of the liquid increases as the curvature of the bent portion increases (the radius of curvature decreases). Moreover, the pressure in the bent portion does not decrease during bending. For this reason, according to this pipe bending apparatus, a pipe having a small difference between the cross-sectional shape of the bent portion and the cross-sectional shape of the straight portion can be formed.

According to a second aspect of the present invention, there is provided the pipe bending apparatus, wherein the plug means for closing one end of the pipe has a pressure corresponding to a bending angle of the bent portion of the pipe, and a liquid in the pipe is provided. Is connected to a pressurizing device for pressurizing. According to the present invention, the pipe is bent such that the larger the bending angle of the bent portion, the higher the pressure of the liquid. Moreover, the pressure in the bent portion does not decrease during bending. For this reason, according to this pipe bending apparatus, a pipe having a small difference between the cross-sectional shape of the bent portion and the cross-sectional shape of the straight portion can be formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of a pipe bending apparatus according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is a side view of a motorcycle equipped with an exhaust pipe formed by a pipe bending apparatus according to the present invention, and FIG. 2 is a view showing an exhaust pipe formed by a pipe bending apparatus according to the present invention. (A) is a plan view, and (b) is a side view showing a state viewed from the left side of the vehicle body. FIG. 3 is a plan view of a bending device, FIG. 4 is a diagram showing a configuration of a water circulation device of the bending device,
FIG. 5 is a cross-sectional view showing a state in which the plug means is attached to the pipe, FIG. 6 is a view showing the structure of the sealing machine, and FIG. 7 is a side view showing the structure of the pressurizing machine. It is drawn with the chuck part broken.

FIG. 8 is a plan view of the folding machine, and FIG. 9 is a rear view of the folding machine. FIG. 10 is a side view of the articulated robot, and FIG.
Is a graph for comparing the performance of the exhaust pipe formed by the bending apparatus according to the present invention with the performance of the exhaust pipe formed by the conventional bending apparatus, and FIG. I have. FIG. 12 is a block diagram showing the configuration of the bending apparatus, and FIG. 13 is a time chart for explaining the operation of the folding machine and the sealing machine.

In FIG. 1, reference numeral 1 denotes a motorcycle equipped with an exhaust pipe 2 formed by a bending apparatus according to the present invention. This motorcycle 1 is equipped with a four-cycle single-cylinder engine 3. Reference numeral 4 denotes a body frame, 5 denotes a front wheel, 6 denotes a rear wheel, 7 denotes a steering wheel, and 8 denotes a seat.

The exhaust pipe 2 is, as shown in FIG.
It is formed in a predetermined shape by bending three places, and a flange 11 for engine connection is welded to one end (upstream end). The three bent portions formed in the exhaust pipe 2 are indicated by reference numerals 12 to 14. As shown in FIG. 1, a rear exhaust pipe 16 provided with a muffler 15 at the rear end is connected to a downstream end of the exhaust pipe 2.

The bent portions 12 to 14 of the exhaust pipe 2
Is bent by a bending apparatus denoted by reference numeral 21 in FIG. The bending apparatus 21 has a structure in which water is filled in the exhaust pipe 2 and the exhaust pipe 2 is bent while being pressurized with a predetermined pressure, and water is inserted into the pipe using a plug means described later. Sealing machine 2 for sealing
2, a pressurizing machine 23 for holding the base end of the pipe in the bending step and pressurizing the water in the pipe, a bending machine 24 for bending the distal end of the pipe, and removing the plug means from the pipe to remove the water. Opener 25 for discharging, and first and second articulated robots 26 and 27 for transporting pipes and plug means.
, A water circulation device 28 (see FIG. 4), a control device 29 (see FIG. 12) for controlling each of the above-described devices, and the like.

As shown in FIG. 5, the sealing machine 22 includes a raw material pipe 3 formed of a straight pipe for forming the exhaust pipe 2.
First and second stopper means 32, 33 are attached to both ends of the first member 1 to seal the inside of the material pipe 31, and the material pipe 31 is filled with water and sealed by using these stopper means 32, 33. . The first and second stopper means 32, 33
As shown in FIG. 5, a cylindrical cylinder 34 with a bottom for fitting the end of the raw material pipe 31 and a rubber rubber seal 36 attached to the cylindrical body 34 with a supporting bolt 35 are provided. I have.

The sealing rubber 36 is made of a material pipe 31.
And is sandwiched between a bottom 34a of a bottomed cylindrical body 34 and a plate 37 supported on the inner end of the support bolt 35. The support bolt 35 is formed such that the plate 37 presses the sealing rubber 36 toward the bottom 34a by tightening a nut 38 screwed to the outer end. That is, by tightening the nut 38, the rubber for sealing 36 becomes the bottom portion 34 a of the bottomed cylindrical body 34.
And the plate 37 squeezes in the axial direction and swells in the radial direction, so that the outer peripheral surface is in close contact with the inner peripheral surface of the material pipe 31 over the entire circumference so as to be liquid-tight.

The first and second plug means 32 and 33 are attached to both ends of the raw material pipe 31 and the sealing rubber 36 of each plug means 32 and 33 is brought into close contact with the raw material pipe 31 so that the inside of the raw material pipe 31 is maintained. Sealed. In FIG.
First plug means 32 attached to the lower end of material pipe 31
Is formed with a through hole 39 so as to communicate the inside and outside of the material pipe 31 with the shaft center of the supporting bolt 35,
The coupler 40 is attached to the outer end of the supporting bolt 35. As is well known in the art, the coupler 40 has a check valve 40a in the internal passage, and is provided with a mating coupler (for example, a coupler for water supply indicated by reference numeral 41 in FIG. 6). The check valve 40a is pushed open by the push rod of a check valve (not shown) provided in the coupler 41, and the check valve of the water supply coupler 41 is also pushed open by the reaction, so that the through hole 39 and the mating side are opened. By communicating with the passage in the coupler and removing the mating coupler,
The check valve 40a of the coupler 40 and the check valve of the mating coupler (water supply coupler 41) are closed by spring force. Check valve 40a
Prevents the intrusion of air from the outside into the material pipe 31 in the detached state and prevents water from leaking from inside the material pipe 31 to the outside. The check valve on the side of the water supply coupler 41 also prevents air from entering the water injection pipe 109 from outside, and also prevents water in the water injection pipe 109 from leaking to the outside.

The other second plug means 33 forms a discharge passage 42 extending to the outside of the material pipe 31 through the axis of the support bolt 35, and includes an on-off valve 43 for opening and closing the discharge passage 42. Installed. At the outlet of the on-off valve 43, a coupler 44, which is different from the coupler 40 in that no check valve 40a is disposed, is attached. Further, a supporting bolt 35 and the plate 3
A communication hole 45 for venting air extending in the lateral direction from the middle of the discharge passage 42 is formed in the discharge passage 42. This communication hole 45
5, is formed so as to open at the highest position in the material pipe 31 with the second plug means 33 attached to the material pipe 31.

As shown in FIG. 6, the sealing device 22 for attaching these plug means to the material pipe 31 comprises a pipe clamping device 51 for holding the material pipe 31 in an upright state so as to extend in the vertical direction, A first clamp device 52 for detachably holding the plug means 32, an actuator 54a for raising and lowering the first clamp device 52 (see FIG. 12), and a second clamp means for detachably holding the second plug means 33. A second clamp device 53; an actuator 54b (see FIG. 12) for raising and lowering the second clamp device 53;
A first nut tightening machine 55 for tightening the nut 38 of the plug means 32, and the nut 3 of the second plug means 33.
8, a first coupler detacher 57 for attaching and detaching the water supply coupler 41 to and from the coupler 40 of the first stopper 32, and a second stopper 33.
Coupler detacher 59 for attaching / detaching a drain / air vent coupler 58 to / from the coupler 44, and a second plug means 33
And an actuator 60 (see FIG. 12) for driving the on-off valve 43 of FIG. It should be noted that the drain / air vent coupler 5
8 does not have a check valve like the coupler 44. This is because the drain / air vent coupler 58 is fixed to the sealing device 22 at the uppermost position of the first drain pipe 112, and water does not leak.

The first and second clamping devices 52,
53 is a pair of first and second plug means 3
The plug means 32 and 33 are formed so as to be gripped by engaging the engagement grooves 62 of the second and third engagement means.
The first clamp device 52 is provided below the material pipe 31, and the second clamp device 53 is provided above the material pipe 31. In this embodiment, the material pipe 3
1 is held at a predetermined height by the pipe clamping device 51, and the first clamping device 52 is
4a, the first clamping device 52
By fitting the first plug means 32 held by the above to the material pipe 31 from below and lowering the second clamp device 53 by the actuator 54b, the second clamp device 5
The second plug means 33 held at 3 is fitted from above.
After that, the nut 38 is tightened by the first nut tightening machine 55, the first plug means 32 is connected to the material pipe 31 in a watertight manner, and the nut 38 is tightened by the second nut tightening machine 56.
The second plug means 33 is connected to the material pipe 31 in a watertight manner.

First and second nut tightening machines 55, 56
Are provided so that the sockets 63 respectively fitted to the nuts 38 can advance and retreat with respect to the nuts 38. The sockets 63 are gear-coupled to independent motors 64, respectively, and are rotated by the respective motors 64 in a state of being fitted to the nuts 38.

As shown in FIG. 7, the pressurizing machine 23 includes a clamp device 65 for detachably holding the first plug means 32 attached to one end of the material pipe 31 and a clamp device 65 for connecting the clamp device 65 to the material pipe 31. The raw material pipe 31 is connected to the clamp device actuator 66 (see FIG. 12) that moves along the longitudinal direction and the coupler 40 of the first plug means 32.
A pressurizing coupler 67 for communicating the inside with a discharge system of a high-pressure pump to be described later, and a coupler detacher 68 for attaching and detaching the pressurizing coupler 67 to and from the coupler 40 of the first plug means 32 (see FIG. 12). And an air vent device 69 for venting the water supply system between the high-pressure pump and the pressurizer 23.

As is well known in the art, the clamping device 65 holds the cylindrical portion 32a by moving the claw 65a inserted into the cylindrical portion 32a of the first plug means 32 radially outward. The structure is The clamp device actuator 66 moves the clamp device 65 forward and backward in the longitudinal direction of the material pipe 31 along a rail indicated by reference numeral 70 in FIG. 3, and moves the clamp device 65 in the circumferential direction of the material pipe 31. It is configured to be able to perform a turning operation for turning.

The pressure coupler 67 has the same structure as that of the water supply coupler 41 of the sealing device 22 described above, and as shown in FIG.
2 is supported. A water passage (not shown) is formed inside the support shaft 71, and a pressure pipe 73 attached to an outer end of the support shaft 71.
Connected to a high-pressure pump described later.

In this embodiment, the support shaft 71 is movably supported by the frame 72, and the compression coil spring 7
4, so as to be urged in the coupler connection direction (to the right in FIG. 7). With this structure, the pressing coupler 67 is connected to the coupler 40 of the first plug means 32.
It can be moved to a position where it can be connected to
Shock at the time of connecting the coupler can be reduced.

The coupler attaching / detaching machine 68 has the same structure as that provided in the sealing device 22, and can be moved integrally with the clamp device 65. The air bleeding device 69 has an air bleeding coupler 75 that is attached to and detached from the pressurizing coupler 67 supported by a frame 72 of the pressurizer 23 via a support member 76 and a support shaft 77. The support shaft 77 is disposed directly above the clamp device 65 in a state where the axis is parallel to the longitudinal direction of the material pipe 31. The support member 76 supports the support shaft 77 so as to be rotatable around an axis, and also supports the support shaft 77 so as to be movable in the axial direction. FIG. 7 shows a state in which the support shaft 77 is rotated around the axis to connect the air bleeding coupler 75 to the clamping device 6.
5 is drawn to the side.

As shown in FIGS. 8 and 9, the bending machine 24 has a first roll die 81A for bending a small curvature (a large radius of curvature) and a lower side of the first roll die 81A. A second roll die 81B for performing bending with a large curvature (small radius of curvature),
First pipe holding portion 81Ab of first roll die 81A
A first cylinder device 82A that presses and clamps the material pipe 31 on the second pipe die, a second cylinder device 82B that presses and clamps the material pipe 31 on the second pipe holding portion 81Bb of the second roll die 81B, and a first and a second device. The first and second cylinder devices 82A, 82B are rotatable integrally with the roll dies 81A, 81B.
, A bending actuator 84 that rotationally drives the support 83, and a rotatable support for the other end of the processing actuator 84, and integrated first and second roll dies 81 A, 81 A, A base 85 for rotatably supporting the base 81B and the support base 83; an elevating actuator 85a for raising and lowering the base 85;
And a rotation angle sensor 86 for detecting rotation angles of the second roll dies 81A and 81B.

The first and second roll dies 81A, 81A,
On the outer peripheral portion of the roll die 81B, semi-circular grooves 81Aa and 81Ba into which the material pipes 31 are fitted are respectively formed on the outer periphery of the roll die 81B.
A and 81B are formed to extend in the circumferential direction. In this embodiment, grooves 8 are formed in the first and second roll dies 81A and 81B so that bent portions having different curvatures can be formed by the plurality of roll dies 81A and 81B.
Two 1Aa and 81Ba are vertically separated from each other.

The first and second cylinder devices 82A, 82B of the bending machine 24 are provided with the two grooves 81Aa, 81A.
They are spaced apart in the vertical direction to correspond to Ba. The actuator 84 presses one end of the support base 83 using the hydraulic cylinder 84a as a drive source.

As shown in FIG. 3, the opening device 25 holds first and second stopper means 32, 33 attached to the bent material pipe 31 (exhaust pipe 2). First and second clamping devices 87 and 88, and first and second for loosening nuts 38 of first and second plug means 32 and 33 held by these clamping devices 87 and 88.
Nut loosening machines 89 and 90 are provided.

The first and second clamping devices 87 and 88 and the nut loosening devices 89 and 90 of the opening device 25 are connected to the sealing device 22.
Devices 52 and 53 and nut tightening machine 5 used in
5, 56 are formed so as to have substantially the same structure.
And the second clamping device 88 and the nut loosening machine 90 are arranged in a horizontal direction (left and right direction in FIG. 3). In this embodiment, a chute 91 for taking out a product is provided between the first and second clamping devices 87 and 88, and the plug means 3 is provided.
The material pipe 31 (exhaust pipe 2) from which the pipes 2 and 33 have been removed can be taken out.

The first and second articulated robots 2
As shown in FIG. 10, a base 93 fixed to a floor 92 and two arms 9 supported by the base 93 are provided.
4, 95 and a clamp 96 for gripping a pipe attached to the distal end of the arm 95 on the distal end side. The range in which the articulated robots 26 and 27 can transport the material pipe 31 is indicated by a two-dot chain line in FIG.

The first articulated robot 26 located on the left side in FIG. 3 performs a transfer operation of transporting the raw material pipe 31 from the raw material pipe stocker indicated by the reference numeral 97 in FIG. Pressing the material pipe 31
3 and a transfer operation for transferring the first and second plug means 32 and 33 from the plug means support base indicated by reference numeral 98 to the sealing apparatus 22 in FIG. A transfer operation of transporting the first and second plug means 32 and 33 to the plug means support base 98 from the downstream end of the transfer means for plug means indicated by reference numeral 99 therein. The stopper transfer device 99 has a structure in which the first and second stoppers 32 and 33 placed at the right end (upstream end) in FIG. 3 are moved to the other end. Note that, without using the first articulated robot 26, a transfer device for transferring the material pipe 31 from the material pipe stocker 97 to the plugging operation region of the first and second plug means 32, 33 is replaced with a sealing machine 22.
May be provided integrally.

The second articulated robot 27 includes a pressurizing machine 23
And a transfer operation for transferring the material pipe 31 from the bending machine 24 to the opening machine 25, a transfer operation for transferring the material pipe 31 from the opening machine 25 to the product take-out chute 91, and a first and a second operation from the opening machine 25. And a transfer operation of transferring the second plug means 32 and 33 to the upstream end of the transfer means 99 for plug means. In FIG. 3, a defective product chute 100 is disposed adjacent to the stock pipe stocker 97 and the plug means support stand 98, and is denoted by reference numeral 100 to discharge defective products.

As shown in FIG. 4, the water circulating device 28 includes first and second water tanks 10 for storing water.
1, 102; a circulating pump 103 for sending water from the first water tank 101 to the second water tank 102;
Pump 104 for supplying water to the pump, and high-pressure pump 105 for supplying water to the pressurizing machine 23 in the bending step.
And so on. The high-pressure pump 105 constitutes a pressurizing device according to the present invention. The first water tank 101
The second water tank 102 and the second water tank 102 are communicated with each other by a communication pipe 106, and the water in both tanks 101 and 102 is circulated by a circulation pump 103. A filter 107 is interposed between the circulation pump 103 and the second water tank 102.

The water injection pump 104 and the high pressure pump 1
Numeral 05 indicates that the water in the second water tank 102 is sucked through each of the foam detection sensors 108. The bubble detection sensor 108 detects bubbles contained in water sucked into the pumps 104 and 105, and outputs detection data to the control device 29 described later. When bubbles are detected by the bubble detection sensor 108, the control device 29 stops both pumps 104 and 105 as a water supply abnormality.

The discharge side of the water injection pump 104 is connected to the water supply coupler 41 by a water injection pipe 109.
Water is supplied into the raw material pipe 31 with the water supply coupler 41 connected to the coupler 40 of the first plug means 32. The drain / air vent coupler 58 connected to the coupler 44 of the second plug means 33 located at the upper end of the material pipe 31 connects the first drain pipe 112 provided with the bubble detection sensor 110 and the flow rate sensor 111. Connected. This first drain pipe 1
The downstream end of 12 is formed to return water to the first water tank 101.

The bubble detection sensor 110 is provided for determining whether or not the air bleeding has been completed. The bubble detection sensor 110 detects bubbles contained in water flowing through the first drain pipe 112, and outputs the detected data to the control unit 29. Output to The flow sensor 111
Detects the flow rate of the water flowing through the first drain pipe 112 and outputs the detection data to the control device 29.

The discharge side of the high-pressure pump 105 is connected to a pressurizing coupler 67 of the pressurizing machine 23 by a pressurizing pipe 73. The pressurizing coupler 67 is the same as the coupler 40 on the material pipe 31 or the coupler. Water is supplied to these in a state where they are connected to the air release coupler 75 of the air release device having the structure. The air bleeding coupler 75 is connected to a second drain pipe denoted by reference numeral 113 in FIGS. 4 and 7 so that water and air are discharged to the first water tank 101 by the second drain pipe 113. I have to. Second drain pipe 113
Also, a bubble detection sensor 110 is interposed so that the controller 29 can determine whether or not the air release is completed.

The pressurizing pipe 7 connected to the high-pressure pump 105
3 is provided with a three-way valve 114 and a pressure sensor 115. The three-way valve 114 connects the supply destination of the water discharged by the high-pressure pump 105 to the pressurizing coupler 67 and the first water tank 10.
It is connected so that it can be switched to either one of them. That is, the three-way valve 114 is
5 and a pressurizing coupler 67, and a pressure relief for connecting the high-pressure pump 105, the first water tank 101, and the pressurizing coupler 67 to each other via a three-way valve 114. The second mode can be adopted. The pressurizing coupler 67, similarly to the water supply coupler 41, is provided with a check valve for preventing the intrusion of air from the outside in the de-mounted state and for preventing the water in the pressurizing pipe 73 from leaking. The coupler 75 has the same structure as the coupler 40 and has a check valve similar to the check valve 40a.

The pressure sensor 115 is connected to the three-way valve 11.
From 4, the water pressure in the pressure pipe 73 is detected on the pressure coupler 67 side, and the detection data is output to the control device 29. In this embodiment, an air-driven plunger pump is employed as the high-pressure pump 105, and the discharge pressure of the high-pressure pump 105 is increased or decreased by the discharge pressure adjusting device 116 (see FIG. 12) changing the pressure of the driving air. I am trying to do it. The discharge pressure adjusting device 116 increases or decreases the pressure of the driving air in accordance with the command value sent from the control device 29.
The command value is set so that the water pressure detected by the pressure sensor 115 matches a predetermined target water pressure.
9 sets. That is, the high-pressure pump 105 is feedback-controlled so that the discharge pressure of the high-pressure pump 105 matches the target water pressure.

The target water pressure is set in accordance with the shape of the exhaust pipe 2. For example, the target water pressure is set in accordance with the curvature of the bent portion. That is, a bent portion having a relatively large curvature (a relatively small radius of curvature) is bent with a higher water pressure than a bent portion having a relatively small curvature.
During bending, control is performed so that the water pressure during bending is constant, or the water pressure is increased as the bending angle of the bent portion increases. The bending angle of the bent part is the bending machine 2
4 is detected by the bending rotation angle sensor 86 provided in the fourth rotation direction.

Next, the operation of the bending apparatus 21 according to this embodiment will be described. When a start switch of an operation panel (not shown) is turned ON, first, the first articulated robot 26 starts the material pipe 31 of the material pipe stocker 97.
Is gripped, and is loaded into the stoppering machine 22 in a state of being vertically extended. When the material pipe 31 is loaded into the stoppering machine 22, first, the pipe clamping device 51 holds the material pipe 31, and the first and second clamping devices 52, 5 are provided.
The first and second plug means 32 and 33 are fitted to the raw material pipe 31 by 3 and the actuators 54a and 54b. Note that these plug means 32 and 33 are transported from the plug means support base 98 by the first articulated robot 26 after the previous water injection step by the plugging device 22 is completed.

After the plug means are fitted to the material pipe 31, the nuts 38 of the plug means are tightened by the first and second nut tightening machines 55 and 56. At this time, the first nut tightening machine 55 rotates after raising the socket 63, and the second nut tightening machine 56 rotates after lowering the socket 63. After the tightening of the nut 38 is completed, the socket 63 is returned to the initial position.

Thereafter, the first and second coupler detachers 5
7, 59 begin to operate, the coupler 4 of the first plug means 32
0 is connected to the coupler 41 for water supply, and the coupler 44 of the second plug means 33 is connected to the coupler 58 for drain / air release. Then, after the actuator 60 for the opening / closing valve 43 opens the opening / closing valve 43 of the second plug means 33, the water injection pump 1
04 starts operation, and water is supplied into the raw material pipe 31 from below through the first plug means 32.

When the inside of the material pipe 31 is filled with water, the water is discharged from the drain passage 42 of the second plug means 33 to the first drain pipe 112 through the on-off valve 43 and the first drain pipe 112. Is detected by the flow rate sensor 111 interposed in the drain pipe 112 of FIG. At the same time, the bubbles contained in the water are detected by the bubble detection sensor 110. The above-described state is maintained until no bubbles are detected from the water flowing through the first drain pipe 112. After the bubbles are no longer detected by the detection signal from the bubble output detection sensor 110, or the flow rate sensor 1
After it is confirmed that the total flow rate obtained by integrating the flow rate signal from 11 is equal to or more than an amount sufficient to fill the material pipe 31 with water, the injection pump 104 is stopped, and the on-off valve actuator 60 is turned on and off. Close 43. Further, the first coupler detacher 57 removes the water supply coupler 41 from the coupler 40 of the first plug means 32, and the second coupler remover 59 removes the drain / air vent coupler 58 from the coupler 44.
Remove from As shown in this embodiment, the material pipe 3
By raising water 1 and injecting water from below and letting air flow out from above, air can be reliably removed.

After the water injection step is completed as described above, after the material pipe 31 previously bent by the pressurizing machine 23 and the bending machine 24 is carried out, the first articulated robot 26 is operated. Press the material pipe 31 from the sealing machine 22
3 and to the bending machine 24. At the time of this transfer, first, the first articulated robot 26 grasps the material pipe 31 of the sealing device 22 and the pipe clamping device 5 of the sealing device 22.
1 opens the material pipe 31 and the first and second stopper means 32, 33
To release. Next, the first articulated robot 26 takes out the material pipe 31 from the sealing machine 22 and loads it into the pressurizing machine 23 and the bending machine 24.

At this time, the raw material pipe 31 is closed at its both ends by the first and second plug means 32 and 33 and is sealed with water, and the base end thereof (the end on the first plug means 32 side). ) Is held by the clamping device 65 of the pressurizing machine 23, and the tip (the end on the second plug means 33 side) is
4 is held by the first clamp device 82. Pressing machine 23
When the material pipe 31 is held by the clamp device 65, the coupler 40 of the first plug means 32 is connected to the pressurizing coupler 67 of the pressurizing machine 23.

Before the material pipe 31 is charged as described above, the pressurizing machine 23 performs at least one
In order to improve bending productivity, the number of bent material pipes 31 must be reduced to several tens, several hundreds, or every lot to remove air from the water passage between the pressure pipe 05 and the coupler 67 for pressurization. Will be implemented. This air bleeding is performed by connecting the coupler 75 of the air bleeding device 69 to the coupler 67 for pressurization and circulating water by the high-pressure pump 105, and detecting bubbles in the water by the bubble detection sensor 110 provided in the second drain pipe 113. Exit when no longer available. When the air bleeding step is completed, the pressurizing coupler 67 is switched to the air bleeding coupler 7.
5 is removed.

The material pipe 31 is divided into a pressurizing machine 23 and a bending machine 24.
After loading the first articulated robot 26, the stoppering machine 22
Are newly loaded with first and second stopper means 32, 33,
The next material pipe 31 is transported from the material pipe stocker 97 to the sealing machine 22. The first and second stopper means 3
A plurality of sets 2 and 33 are prepared in advance and placed on the stopper support 98. Thus, the next material pipe 31
Is loaded into the sealing device 22, the sealing device 22 performs the water injection operation again. That is, while the bending process is performed by the pressurizing machine 23 and the bending machine 24, water injection into the next material pipe 31 is performed by the sealing device 22.

The material pipe 31 is connected to the pressurizing machine 23 and the bending machine 24.
Then, the high pressure pump 105 is operated to increase the pressure of the water in the raw material pipe 31. At the time of this pressure rise, after reaching a pressure of about 90% of the target water pressure set in accordance with the curvature of the bent portion, the pressure is gradually increased to the target water pressure by feedback control. After reaching the target water pressure,
The support 83 is driven by the bending actuator 84 of the bending machine 24 to bend the material pipe 31 so as to wind it around the roll die 81.

In this bending process, the base end of the raw material pipe 31 is held by the pressurizing machine 23, and the front end is attached to the first cylinder holding unit 81Ab of the upper first roll die 81A by the first pipe holding unit 81Ab. With the piston tip 82Aa pressed and clamped, the machining actuator 8
4 is extended, and a portion closer to the pressurizing machine 23 than the tip of the material pipe 31 is formed into the groove 81Aa of the first roll die 81A.
And wrap it around. This bending is performed until the angle detected by the bending rotation angle sensor 86 reaches the designed bending angle of the bent portion. During the bending process, the pressing device 23 moves the clamping device 65 to the bending machine 24 side (the right side in FIG. 3) during the bending process so that an excessive tensile load is not applied to the material pipe 31 at the time of bending.
To move.

At the time of bending, the material pipe 31 slightly elongates in the longitudinal direction even by the movement of the clamp device 65, so that the volume in the bent portion increases and the water pressure decreases. However, a pressure drop is detected by the pressure sensor 115 between the high-pressure pump 105 and the inside of the material pipe 31, and the discharge pressure of the high-pressure pump 105 is feedback-controlled so that the water pressure in the material pipe 31 maintains the target water pressure. For this reason, the inside of the bent portion is maintained at the target water pressure throughout the entire bending process. The target water pressure is gradually increased as the bending angle increases (the length of the bent portion increases).

In this embodiment, the three bent portions 12 to 14 of the exhaust pipe 2 shown in FIG. 2 are sequentially bent from the downstream side. That is, the first pipe holding portion 81Ab of the bending machine 24 and the first cylinder device 82A make the raw material pipe 31
And the bent portion 12 on the most downstream side and the bent portion 13 at the center are bent, and the second pipe holding portion 81Bb and the second cylinder device 82B hold the material pipe 31 at the most upstream position. The bent portion 14 on the side is bent.

In order to bend the middle bent portion 13 after bending the most downstream bent portion 12, first, after bending the downstream bent portion 12 is completed, the bending machine 24 The piston tip 82Aa is retracted to open the material pipe 31, and the bending actuator 84 is returned to the initial position. At the time of this setup change, the three-way valve 114 is switched so that water is returned from the high-pressure pump 105 to the first water tank 101. Next, the clamp device 65 of the pressurizing machine 23 is rotated and moved to the bending machine 24 side, and the portion forming the central bent portion 13 is fitted into the groove 81Aa of the first roll die 81A.

Then, the tip end portion 82Aa of the piston is pressed against the first pipe holding portion 81Ab to hold the end portion of the material pipe 31 again, and the bending actuator 84 of the bending machine 24 is operated to operate the central bent portion. Fold 13
At the time of bending, the three-way valve 114 is switched to switch the high-pressure pump 10
From 5, water pressure is applied to the inside of the material pipe 31, and the discharge pressure of the high-pressure pump 105 is feedback-controlled as in the previous bending. The central bent portion 13 has the same curvature as the downstream bent portion 12 but has a small bending angle (the bent portion is obtuse), so the target water pressure is set lower than the bent portion 12. This is because when the bending angle is small, flattening hardly occurs, so that a large water pressure is not required.

After bending the central bent portion, the piston tip portion 82Aa is retracted to open the exhaust pipe 31, and the bending actuator 84 is returned to the initial position, and the base of the bending machine 24 is moved up and down. The base is raised by driving the raising / lowering actuator 85a to be moved. At the time of this setup change, water is supplied from the high-pressure pump 105 to the first water tank 10.
The three-way valve 114 is switched so as to return to 1. The second pipe holding portion 81B of the bending machine 24 is
b and the second cylinder device 82B can hold the leading end of the material pipe 31. After descending as described above, the clamp device 65 of the pressurizing machine 23 rotates the material pipe 31 and moves to the bending machine 24 side, and fits the last bent portion 14 into the lower groove 81b on the lower side of the roll die 81. Let it.

After the positioning is completed, the bending machine 24
Pipe holding portion 81Bb and second cylinder device 8
The end of the material pipe 31 is held by 2B, and the bending actuator 84 is operated to bend the last bent portion 14. Also at the time of this bending, the three-way valve 114 is switched to apply water pressure from the high-pressure pump 105 to the inside of the material pipe 31 to feedback-control the discharge pressure of the high-pressure pump 105. The bent portion 14 has a larger curvature (smaller radius of curvature) than other portions, and the lower groove 81 of the second roll die 81B.
When the groove radius of Ba is larger than the groove radius of the upper groove 81Aa, the target water pressure at the time of bending is increased in accordance with the curvature. Note that the groove radius of the roll die is slightly smaller than the radius of curvature of the finished product, and the bending angle of the bending machine 24 is larger than the bending angle of the finished product,
The correct finished product shape is obtained even if the springback phenomenon occurs.

After the three bent portions 12 to 14 are bent, the pressurization by the high-pressure pump 105 is stopped and the pressure in the material pipe 31 is reduced. At this time, the three-way valve 114 is switched so that the high-pressure pump 105 communicates with the first water tank 101 and the material pipe 31, and the water pressure in the material pipe 31 is reduced to stop the high-pressure pump 105. Thereafter, the material pipe 31 is gripped by the second articulated robot 27, and the coupler 40 of the first plug means 32 is pressed from the coupler 40 of the first plug means 32 by the coupler attaching / detaching machine 68 of the pressing machine 23.
And the material pipe 31 is removed from the pressurizing machine 23 and the bending machine 24.

The bent material pipe 31 is transported to the opening device 25 by the second articulated robot 27 and the first plug means 3
2 is loaded into the first clamping device 87 of the stopper 25.
After the material pipe 31 is removed from the pressurizing machine 23 and the bending machine 24 by the second articulated robot 27 in this way,
In the pressurizing machine 23 and the bending machine 24, the next material pipe 31 is transported from the sealing machine 22 by the first articulated robot 26, and the material pipe 31 is bent.

The first clamping device 87 of the opening device 25
When the first stopper means 32 at one end of the material pipe 31 is loaded into the first stopper means 87,
Is held, the first nut loosening machine 89 loosens the nut 38 of the first plug means 32. After the nut 38 is loosened in this way, the second articulated robot 27
Is pulled out from the first clamp device 87 and removed.
By this operation, the first stopper means 32 remains in the stopper 25 and comes off from the material pipe 31. The water filled in the raw material pipe 31 flows down to a drainage device (not shown) provided below the stopper 25 and is returned to the first water tank 101.

Next, the second articulated robot 27 loads the second stopper means 33 into the second clamping device 88 of the stopper 25. The same operation as the removal operation by the first clamp device 87 is performed in the second clamp device 88,
Is removed from the material pipe 31. After removing the plug means 32 and 33 from both ends of the material pipe 31 in this way, the second articulated robot 27 places the material pipe 31 on the product take-out chute 91. The chute 91 moves the material pipe 31 to a product outlet (not shown).

As described above, the second articulated robot 27 that has transferred the material pipe 31 to the chute 91,
The first and second plug means 32, 33 remaining in 5 are conveyed to the upstream end of the transfer means 99 for plug means, and are bent by the pressurizing machine 23 and the bending machine 24 on the next material pipe 31. Wait for the end. After the two stoppers 32 and 33 placed on the stopper transferring device 99 are transferred to the downstream end of the stopper transferring device 99, the first articulated robot 26 moves the stopper supporting base. 98.

In the pipe bending apparatus 21 configured as described above, as shown in FIG. 13, the bending work by the pressurizing machine 23 and the bending machine 24 and the water injection and sealing work by the sealing machine 22 are performed. Done at the same time. Although not shown in FIG. 13, the opening operation is also performed in parallel with the bending process. For this reason, compared with the case where the above-described operations are sequentially performed on one material pipe 31 to manufacture the material pipe 31, the waiting time is reduced, and the processing time can be shortened as much as possible.

The bent portion of the exhaust pipe 2 bent by the pipe bending apparatus 21 is bent while pressurizing the water sealed in the pipe with a pressure corresponding to the curvature. The pressure in the bent portion does not decrease, and there is no deformation such that the outside of the bend is depressed inward during bending. As a result, molding was performed so that the flatness at the bent portion was 92% or more. The flatness here means that a pipe having a substantially uniform thickness with a circular outer shape is deformed at the bent portion,
Although it is substantially elliptical, a value obtained by dividing the minor diameter of this substantially elliptical shape (minimum outer diameter at the bent portion) by the pipe outer diameter before bending is 10%.
This is a value obtained by multiplying by zero. Further, as shown in this embodiment, a single exhaust pipe 2 has a plurality of bent portions 12 to 1.
Even in the case of forming 4, since the water pressure is set in accordance with the curvature of each bent portion, it is possible to mold the flat portion to be 92% or more in all the bent portions. .

Further, as the bending angle of the bent portion is larger, the water pressure is increased and the bending is performed, so that the pressure in the bent portion during the bending can be prevented from lowering. For this reason, even if the bending angle of the bent portion is large, the bending portion can be bent so as to increase the flatness, and as shown in this embodiment, three bent portions having different lengths of the bent portion are provided. The portion could be formed so that the flatness was 92% or more in all the bent portions.

The exhaust pipe 2 in which the flatness of the bent portion is 92% or more has a difference between the inner diameter of the straight portion and the inner diameter of the bent portion,
That is, the difference in the cross-sectional area inside the pipe is reduced, the exhaust gas can flow smoothly in the pipe, and the reflection of the pressure wave on the way decreases. Therefore, the output of the engine 3 can be improved by using the exhaust pipe 2. FIG. 11 shows the difference between the output change of the engine 3 to which the exhaust pipe 2 is attached and the output change of the engine 3 to which the conventional exhaust pipe 2 is attached.

In FIG. 11, the case where the exhaust pipe 2 formed by the bending apparatus 21 according to this embodiment is used is shown by a solid line, and the case where the conventional exhaust pipe 2 is used is shown by a broken line. As can be seen from the drawing, the output (maximum output) in the high rotation range is increased by using the exhaust pipe 2 formed by the bending apparatus 21 according to this embodiment.

(Second Embodiment) A stoppering machine can be configured as shown in FIG. FIG. 14 is a side view showing another embodiment of the sealing device. In FIG. 14, the same or equivalent members as those described with reference to FIGS. Omitted.

The sealing device 22 shown in FIG. 14 comprises a pipe clamping device 51 for holding the raw material pipe 31 and a first and second plug means 3 at the bottom of a water tank 201 storing water.
First and second clamping devices 52 and 53 for detachably holding the first and second clamps 2 and 33 are provided, and inside the water tank 201 (underwater).
And the first and second stopper means 32, 33
The mounting structure is adopted.

In the nut tightening machines 55 and 56 for tightening the nuts 38 of the plug means 32 and 33, only the shaft 202 supporting the socket 63 is inserted into the water tank from the side. The shaft 202 penetrates a seal member 204 provided on a side wall 203 of the water tank 201, so that water does not leak out of the water tank even when it is rotated and translated in the axial direction.

In the sealing device 22 thus configured, the material pipe 31 is moved by the first articulated robot 26.
The first and second plug means 32 and 33 are attached while the pipe is immersed in a water tank in a state of being inclined and held by the pipe clamp device 51. When this mounting operation is completed, water is sealed in the material pipe 31.
That is, the air bleeding operation performed in the case of employing the first embodiment becomes unnecessary. For this reason, since the second plug means 33 does not need to adopt a structure for venting air, it can be formed into a simple structure that only functions as a blind plug.

[0074]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Exhaust pipe 2 shown in the above embodiment
Is made of SUS304L with a circular outer shape and an outer diameter of about 3
It was formed by bending a material pipe 31 of 8 mm and 0.8 mm having a substantially uniform thickness. The radius of curvature of the bent portion is about 60 mm (the radius of the groove is 58 mm) at all three places, and the water pressure at the time of bending is 11 when the bending angle is 33.5 °.
0 kg / cm ² , 155 kg / c when the bending angle is 180 °
It was m ^2. After bending under these conditions,
The flattening rate was 97%. Although the exhaust pipe of the above-described embodiment is made of stainless steel having a circular outer shape and a substantially uniform thickness, the present invention is not limited to this. The present invention is also applicable to exhaust pipes having a rectangular or polygonal outer shape, ordinary steel pipes in which the material side is coated with molten aluminum, or heat-resistant copper-based alloy pipes. Even for pipes whose outer shape is not irregular or have no uniform wall thickness, the inside diameter of the pipe is bent and formed by applying internal pressure, and the minimum outer diameter on the side where the outer diameter shrinks due to bending is the location where this minimum outer diameter is measured. If the flatness, which is a value obtained by multiplying the value obtained by dividing the pipe outer diameter before bending by 100, by 100, is 92% or more, the exhaust pulsation is not disturbed at the bent portion, and the exhaust pulsation can be effectively utilized. is there.

That is, depending on the shape and the bending direction of the straight portion, not only the cross-sectional area inside the pipe at the bent portion is reduced but also increased (the bent portion at the side where the outer diameter is reduced due to bending). The outer diameter before bending is larger than the outer diameter before bending on the side where the outer diameter increases due to bending). If it increases, the bent portion will function as an expansion chamber, and the reflected wave 180 ° out of phase will return to the engine side, disturbing the exhaust pulsation of the engine and deteriorating the performance. Those having a rate of 92% or more do not have such a phenomenon, and the exhaust pulsation can be effectively used.

In the pipe bending apparatus of the above embodiment, a stainless steel exhaust pipe having a circular outer shape and a substantially uniform wall thickness is exemplified as a bending object, but the present invention is not limited to this. Can be pipes that are circular and have uneven wall thickness, pipes that have a rectangular or polygonal outer shape, ordinary steel pipes with a molten aluminum plating on the material side, or those made of heat-resistant copper-based alloys it can. In addition to the engine exhaust gas, pipes for sending various gases and liquids can also be bent.

According to the pipe bending apparatus of the present invention,
Even for pipes whose outer shape is not irregular or have no uniform wall thickness, the inside diameter of the pipe is bent and formed by applying internal pressure, and the minimum outer diameter on the side where the outer diameter shrinks due to bending is the location where this minimum outer diameter is measured. The value divided by the corresponding pipe outer diameter before bending is 10
The flatness, which is a value obtained by multiplying by zero, can be 92% or more. In an exhaust pipe having the flatness of 92% or more, the exhaust pulsation can be effectively utilized without disturbing the exhaust pulsation at the bent portion. is there.

That is, depending on the shape of the straight portion and the bending direction, not only the cross-sectional area inside the pipe at the bent portion is reduced but also increased (the minimum at the side where the outer diameter is reduced due to the bending). The outer diameter is larger than the outer diameter on the side where the outer diameter increases due to bending, etc.). If it increases, the bent portion will function as an expansion chamber, and the reflected wave 180 ° out of phase will return to the engine side, disturbing the exhaust pulsation of the engine and deteriorating the performance. Those having a rate of 92% or more do not have such a phenomenon, and the exhaust pulsation can be effectively used.

Further, even in a pipe for sending various gases and liquids having an aspect ratio of 92% or more as described above, there is no sudden change in the cross-sectional shape and the cross-sectional area, and the transport resistance can be reduced. In addition, when a bent pipe is used as a structural member, by setting the flatness to 92% or more, the bending strength is increased.
The appearance can be excellent.

[0080]

As described above, according to the present invention, the larger the curvature of the bent portion, the higher the pressure of the liquid and the lower the pressure in the bent portion during the bending can be prevented. it can. For this reason, according to the pipe bending apparatus of the present invention, the difference between the cross-sectional shape of the bent portion and the cross-sectional shape of the straight portion can be reduced, so that the exhaust gas flows smoothly in the pipe. And an exhaust pipe in which pressure waves are hardly reflected on the way can be formed.

According to the second aspect of the present invention, the larger the bending angle of the bent portion, the higher the pressure of the liquid, and it is possible to prevent the pressure in the bent portion from decreasing during the bending. For this reason, according to the pipe bending apparatus of the present invention, the difference between the cross-sectional shape of the bent portion and the cross-sectional shape of the straight portion can be reduced, so that the exhaust gas flows smoothly in the pipe. And an exhaust pipe in which pressure waves are hardly reflected on the way can be formed.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle equipped with an exhaust pipe formed by a bending apparatus according to the present invention.

FIG. 2 is a view showing an exhaust pipe formed by a bending apparatus according to the present invention.

FIG. 3 is a plan view of a bending device.

FIG. 4 is a diagram showing a configuration of a water circulation device of the bending device.

FIG. 5 is a sectional view showing a state in which a plug means is attached to a pipe.

FIG. 6 is a diagram showing a configuration of a sealing machine.

FIG. 7 is a side view showing a configuration of the pressurizing machine.

FIG. 8 is a plan view of the bending machine.

FIG. 9 is a rear view of the folding machine.

FIG. 10 is a side view of the articulated robot.

FIG. 11 is a graph for comparing the performance of an exhaust pipe formed by a bending apparatus according to the present invention with the performance of an exhaust pipe formed by a conventional bending apparatus.

FIG. 12 is a block diagram illustrating a configuration of a bending device.

FIG. 13 is a time chart for explaining the operation of the folding machine and the sealing machine.

FIG. 14 is a side view showing another embodiment of the sealing apparatus.

[Explanation of symbols]

2 ... exhaust pipe, 22 ... sealing machine, 23 ... pressurizing machine, 24 ...
Bending machine, 25 ... opener, 26 ... first articulated robot,
27: second articulated robot, 31: material pipe, 32
... first plug means, 33 ... second plug means, 201 ... water tank.

Claims (2)

[Claims] 1. A pipe bending apparatus for closing both ends of a pipe by a plug means and bending the liquid in a sealed state in the pipe, wherein the plug means for closing one end of the pipe comprises: A pipe bending apparatus, wherein a pressurizing device for pressurizing the liquid with a pressure corresponding to a curvature of a bent portion of the pipe is connected. 2. A pipe bending apparatus in which both ends of a pipe are closed by plug means and a liquid is sealed in the pipe in a bent state, wherein the plug means for closing one end of the pipe comprises: A bending device for pipes, wherein a pressurizing device for pressurizing the liquid with a pressure corresponding to a bending angle of a bent portion of the pipe is connected.