JP6532389B2 - Pipe bending unit and pipe bending apparatus provided with the unit - Google Patents

Description

  The present invention relates to a pipe bending type unit suitable for bending a pipe, and a pipe bending apparatus provided with the unit.

  Various bending processes such as press bending, compression bending, tensile bending, pull bending, etc. are known as bending processes for pipes, but rotary drawing bending is most frequently used. In a general rotary draw bending process, a pipe is gripped by a gripping mold against a bending mold having a groove formed on the outer peripheral surface, and the pipe is pressed by a pressure mold in a bending mold direction while bending the mold (and the gripping mold) When rotationally driven, the pipe moves in a tangential direction and is bent along the groove of the bending die, and is described, for example, in the second column of Patent Document 1; [0006] (Bending mold is described as a roll mold) and is disclosed.

  Patent Document 2 proposes a wiper capable of coping with wear and tear caused by sliding with respect to a wiper (shoe) provided to prevent wrinkles generated inside a bent portion of a pipe (Patent Document 2). Described in paragraphs [0013] and [0014] of Similarly, according to Patent Document 3, there is no difference in level between the wiper and the bending die, and there is no problem in using pipes made of various materials, and it has extremely long life. The object of the present invention is to provide a pipe bending apparatus which does not need to frequently perform equipment adjustment work, “a bending die whose outer peripheral surface is formed in an arc shape with a predetermined curvature to bend a pipe, and the bending A pipe bending apparatus comprising: a clamp member for clamping a pipe between a die; and a wiper for rotating the clamp member about the bending die to prevent generation of wrinkles when bending the pipe. The tip end portion of the wiper in the rotational direction of the clamp member is extended along the curvature of the outer peripheral surface of the bending die beyond the bending start point of the pipe. Are plan (described in paragraph of Patent Document 3 [0005] and [0006]).

  Further, Patent Document 4 relates to a method and apparatus for "changing die sets quickly and accurately for bending tubes of different dimensions or for different types of tube bending operations", for "tube bending operations. A pressure die and a clamp die are releasably coupled to one another in a die set provided a pre-assembled die set including a bending die, a clamp die and a pressure die and being attachable to a spindle of a tube bending table And means for simultaneously operating the die set coupled with the die set to simultaneously lift the die including the die set from the table. (Described on page 7 of Patent Document 4). And, "Many tube bending operations require the use of wiper dies and mandrels, but if necessary they are also part of the pre-assembled die set" Page 8), an embodiment in which the wiper die is connected to the bending die by a wiper die arm is also disclosed (page 15 and FIG. 6).

U.S. Pat. No. 5,337,590 Unexamined-Japanese-Patent No. 2004-9125 JP, 2008-246504, A Japanese Patent Application Publication No. 11-512029

  Although the above patent document 1 is configured to actively form wrinkles, in general, in order to eliminate wrinkles in rotational draw bending, wrinkle control is used, and in patent documents 2 to 4, A wiper is provided. Among them, the wipers described in Patent Documents 2 and 4 are formed in a wedge shape at the tip end. In Patent Document 2, there is a concern about wear of the edge portion at the tip, and the countermeasure is taken. In particular, a step is present between the wiper and the bending die along the bending start line of the pipe (usually, a line where the plane including the rotation axis of the bending die intersects the groove inner surface of the bending die). Wrinkles caused by the step can not be avoided. In order to minimize this, it is essential to maintain the wedge shape of the tip of the wiper, and in particular, it is fragile because the tip needs to be made as thin as possible, and the durability is poor. Also, regular wear measures are inevitable and frequent replacement is required. Moreover, since the initial setting of the bending process is difficult, a skilled technique is required. Therefore, it is difficult to continuously perform a large amount of bending.

  On the other hand, the wiper described as one embodiment in Patent Document 3 constitutes a part of the central die part of the bending dies divided into three in the vertical direction, and a recess having an arc-shaped cross section is formed. (Described in paragraphs [0025] to [0030] of Patent Document 3), it states that "there is no need to form a tip having an edge structure, and there is no risk that a step will occur with a bending die". (The same paragraph [0032]), but the explanation during this is unclear. Temporarily, for the pipe to be processed, from the start to the end of bending, among the bending dies divided by three planes parallel to the pipe axis, the upper and lower side die parts contribute to the bending and the central part serves as a wiper Not only is it difficult to prevent the occurrence of wrinkles, but it is also difficult to properly perform bending itself if a separate operation to function is performed, and a configuration that allows desired bending to be performed. There is no disclosure.

  On the other hand, U.S. Pat. No. 5,075,014, that bending dies, clamp dies and pressure dies can replace pre-assembled die sets for bending tubes of different dimensions or for different types of tube bending operations. Although configured, the wiper die is not necessarily required (described on page 11 of Patent Document 4). Therefore, although Patent Document 4 focuses on the change-over function, it does not disclose a replaceable die set including a function that can appropriately prevent the occurrence of wrinkles, and it is possible to bend a pipe. Neither is it suggested a suitable pipe bending unit and a device comprising the same.

  Also, the pipe bending unit is generally composed of metal lumps, and the mass tends to be large, and when the pipe to be processed is large in diameter and the radius of bending is large, it becomes larger and can not be overlooked It becomes weight. In particular, when replacing the unit at a production site, it is necessary to lift the unit from the base of the bending apparatus when performing so-called change-over, but it can not be lifted by hand. For this reason, not only a crane and an auxiliary tool are needed, but also these operations take time and the working efficiency is lowered, so improvement of the stage change workability is desired.

  Therefore, the present invention provides a pipe bending type unit capable of appropriately performing bending processing on a pipe without concern about the occurrence of wrinkles, and easily changing the level, and a pipe bending apparatus provided with the unit. Make it another task.

  In order to achieve the above object, the present invention is provided with a bending die having a pipe receiving groove with a semicircular cross-section on the outer peripheral surface and driven to rotate around a rotation axis, and the bending die has a semicircular cross-section A gripping member having a circular first groove and having a fitting recess formed in the first groove and extending a first predetermined distance in a circumferential direction in a plane orthogonal to the rotation axis; A second groove having a semicircular cross section on the outer peripheral surface, and a fitting protrusion extending a second predetermined distance in the circumferential direction from the tip of the second groove, the fitting protrusion being It has a counter pressure member that fits in the fitting recess and combines the first groove and the second groove to form a pipe receiving groove with a semicircular cross section, and the rotation axis is on the central axis, A hollow shaft member rotatably supporting the gripping member and the counter pressure member, and an engaging portion accommodated in the hollow shaft member and engaged with the hollow shaft member And a fixed shaft member having a fixed portion at at least one end, wherein at least the gripping member and the hollow shaft member are radially about the axis of the fixed shaft member and the axial direction of the fixed shaft member And the fixed shaft member is mounted via the cutaway portion, and the counter pressure member and the grip member are hollow shafts. It is connected by the hinge connection via the member, and it is set as the structure supported rotatably relatively centering | focusing on the said rotating shaft.

  In the above-mentioned pipe bending type unit, the C-shaped rotational support having the opening having a width exceeding the radial width of the fixed shaft member in the radial direction and rotatably supported by the hollow shaft member. A portion of the rotational support portion constitutes the fitting convex portion, and the outer peripheral surface of the rotational support portion is a curved surface forming a portion of the pipe receiving groove having a semicircular cross section. You should do it. Further, the counter pressure member may be a first member having the rotation support portion as a main portion, and a second member joined to the first member to constitute the second groove portion and the fitting convex portion. It is good to be equipped.

  In each of the above-mentioned pipe bending units, a part of the fitting convex portion is located on the front side in the advancing direction of the pipe to be processed with respect to the bending start position of the pipe, and the other of the fitting convex portions It is preferable that the portion be positioned on the rear side with respect to the advancing direction of the pipe with respect to the bending start position of the pipe. Alternatively, the fitting portion of the fitting convex portion to be fitted to the fitting recess is located on the front side in the traveling direction of the pipe with respect to the bending start position of the pipe to be processed, The contact portion between the first groove portion and the second groove portion of the counter pressure member may be positioned on the rear side in the advancing direction of the pipe with respect to the bending start position of the pipe. Furthermore, the bending die may be composed of a plurality of members divided in a plane perpendicular to the central axis of the hollow shaft member.

  Further, according to the present invention, there is provided a bending die having a pipe receiving groove having a semicircular cross section on the outer peripheral surface and driven to rotate around a rotation axis, and a pipe to be processed disposed in the pipe receiving groove of the bending die. And a pressure mold for pressing the pipe in the direction of the bending mold, wherein the bending mold has a first groove with a semicircular cross section on the outer peripheral surface and is formed in the first groove A holding member having a fitting recess extending a first predetermined distance in a circumferential direction in a plane orthogonal to the rotation axis, a second groove having a semicircular cross section on an outer peripheral surface, and the second A fitting protrusion extending a second predetermined distance in the circumferential direction from the tip of the groove, the fitting protrusion being fitted in the fitting recess, and the first groove and the second groove And a pressure bearing member that forms the pipe receiving groove having the semicircular cross-section, and the rotation shaft as a central axis, and the gripping member and the front A hollow shaft member rotatably supporting a counter pressure member, and a fixed shaft member having an engaging portion accommodated in the hollow shaft member and engaged with the hollow shaft member and having a fixing portion at least at one end And at least the gripping member and the hollow shaft member are formed in the radial direction about the axis of the fixed shaft member and in the axial direction of the fixed shaft member and have a width exceeding the radial width of the fixed shaft member. It has a notch, and the fixed shaft member is mounted through the notch, and the counter pressure member and the grasping member are connected by hinge connection via the hollow shaft member, and the rotation shaft is centered Abstract: A pipe bending apparatus is provided that is relatively rotatably supported to constitute a pipe bending unit.

  In the above-mentioned pipe bending apparatus, the counter pressure member is a C-shaped rotary support having an opening whose width is larger than the radial width of the fixed shaft member in the radial direction so as to be rotatably supported by the hollow shaft member. A portion of the rotational support portion constitutes the fitting convex portion, and the outer peripheral surface of the rotational support portion is a curved surface forming a portion of the pipe receiving groove having a semicircular cross section. You should do it. Further, the counter pressure member may be a first member having the rotation support portion as a main portion, and a second member joined to the first member to constitute the second groove portion and the fitting convex portion. It is good to be equipped.

  In the above-mentioned pipe bending apparatus, a part of the fitting convex portion is located forward of the bending start position of the pipe in the advancing direction of the pipe, and the other part of the fitting convex portion is It is preferable that the pipe be positioned on the rear side with respect to the advancing direction of the pipe with respect to the bending start position of the pipe. Alternatively, the fitting portion of the fitting convex portion to be fitted to the fitting recess is located on the front side in the advancing direction of the pipe with respect to the bending processing start position of the pipe, and The contact portion between the groove portion and the second groove portion of the counter pressure member may be positioned on the rear side in the advancing direction of the pipe with respect to the bending start position of the pipe. Furthermore, the bending die may be composed of a plurality of members divided in a plane perpendicular to the central axis of the hollow shaft member.

  In each of the above-mentioned pipe bending apparatuses, a tip is inserted into the pipe, and the core metal is driven so that the tip is opposed to the pressure mold within a predetermined rotation range of the bending mold. It is also good.

  Since the present invention is configured as described above, the following effects can be obtained. That is, in the pipe bending die unit of the present invention, the bending die constituting the same has the first groove having a semicircular cross section on the outer peripheral surface and is formed in the first groove and is orthogonal to the rotation axis A gripping member having a fitting recess extending a first predetermined distance in a circumferential direction in a plane, and a second groove having a semicircular cross section on the outer peripheral surface, and in the circumferential direction from the tip of the second groove A pipe receiving groove having a semicircular cross-section having a semicircular cross section, which has a fitting protrusion extending a second predetermined distance, and the fitting protrusion fits into the fitting recess and joins the first groove and the second groove. An anti-pressure member to be formed, a hollow shaft member having a rotation axis as a central axis and rotatably supporting the gripping member and the anti-pressure member, and an engaging portion accommodated in the hollow shaft member and engaged with the hollow shaft member And a fixed shaft member having a fixed portion at at least one end, and at least a gripping member and a hollow shaft member Each has a notch formed in the radial direction centering on the axis of the fixed shaft member and in the axial direction of the fixed shaft member and having a width exceeding the radial width of the fixed shaft member, and the fixed shaft member through this notch Since the counter pressure member and the grip member are connected by hinged connection via the hollow shaft member and are supported so as to be relatively rotatable about the rotation axis, the concern is not to worry about the occurrence of wrinkles. It is possible to properly bend the pipe. Moreover, if a plurality of pipe bending die units are prepared in accordance with the shape of the pipe to be processed, it is only necessary to select and replace the pipe bending die unit according to the shape when bending for various pipe shapes. As it is good, it is possible to provide a pipe bending type unit that is easy to change stages and does not require adjustment after the change. In particular, the fixed shaft member can be mounted through the notch portion of the holding member and the hollow shaft member. In other words, the holding member and the hollow shaft member can be attached to the fixed shaft member through the respective notches. Since it is possible to easily change the stage only by, for example, horizontal movement of the holding member and the hollow shaft member, it is not necessary to lift a heavy load, and good workability can be ensured.

  In the above-mentioned pipe bending type unit, the counter pressure member has a C-shaped rotary support portion rotatably supported by the hollow shaft member and having an opening having a width exceeding the radial width of the fixed shaft member in the radial direction. Assuming that a part of the rotation support portion constitutes a fitting protrusion, and the outer peripheral surface of the rotation support portion is a curved surface forming a part of a pipe receiving groove having a semicircular cross section, the C character The fixed shaft member can be mounted via the gap of the rotation support portion in the form of a circle, in other words, since the rotation support portion can be mounted via the gap to the fixed shaft member, the holding member for the fixed shaft member and the hollow shaft Along with the mounting of the members or after these mounting, the rotary support can be easily mounted, and the stage change can be performed more easily. Further, the counter pressure member includes a first member having a rotation support portion as a main portion, and a second member joined to the first member and constituting a second groove portion and a fitting convex portion. Thus, the counter pressure member can be configured easily and inexpensively. For example, since it can be configured such that only the second member with high wear during processing can be replaced, an inexpensive antipressure member can be provided from the viewpoint of long-term use. The first and second members may be further divided into a plurality of members so that only the member including the portion susceptible to wear can be replaced.

  Furthermore, in the above-mentioned pipe bending type unit, a part of the fitting convex portion is located on the front side in the advancing direction of the pipe with respect to the bending start position of the pipe to be processed, and the other part of the fitting convex portion is The structure located on the rear side with respect to the pipe bending start position with respect to the pipe bending start position, or the fitting portion of the fitting convex portion fitted in the fitting concave portion starts the pipe bending The contact portion between the first groove of the gripping member and the second groove of the counter pressure member, which is located forward of the pipe in the direction of movement of the pipe relative to the position, If it is set as the structure located in the back side, a smooth bending process can be performed, without generating a wrinkle in a pipe. Furthermore, if the bending die is composed of a plurality of members divided in a plane orthogonal to the central axis of the hollow shaft member, the number of parts is increased compared to the above-mentioned configuration, but it is required for each part It can manufacture with the precision according to the function to be performed, and manufacture of each part becomes easy. In addition, for example, it is possible to easily change the stage only by the horizontal movement of the holding member and the hollow shaft member.

  The pipe bending apparatus according to the present invention comprises a pipe bending unit configured as described above, a gripping type for gripping a pipe to be processed disposed in a pipe receiving groove of the bending type, and a pipe bending type It is equipped with a pressure die that presses in the direction, and by rotating the holding die and the bending die while pressing the pipe in the bending die direction by this pressure die, it is appropriate to bend the pipe without concern about the occurrence of wrinkles It can be done to Moreover, if a plurality of pipe bending die units are prepared in accordance with the shape of the pipe to be processed, it is only necessary to select and replace the pipe bending die unit according to the shape when bending for various pipe shapes. Since the change is good, it is possible to easily change the setting, and the adjustment after the change is not necessary. In particular, the holding member and the hollow shaft member can be attached to the fixed shaft member through the notches, and for example, the step change can be easily performed only by the horizontal movement of the holding member and the hollow shaft member. Since it is possible, it is not necessary to lift a heavy load, and good workability can be ensured.

  In the above-mentioned pipe bending apparatus, the counter pressure member is provided with a C-shaped rotary support as described above, and a part of the rotary support constitutes a fitting convex, and the outer periphery of the rotary support If the surface is a curved surface which forms a part of a pipe receiving groove having a semicircular cross section, the fixed shaft member can be mounted through the gap of the C-shaped rotational support portion, in other words, fixed Since the rotation support can be attached to the shaft member via the air gap, the rotation support can be easily attached together with or after attachment of the holding member and the hollow shaft member to the fixed shaft, It is possible to make the change more easily. Further, the counter pressure member includes a first member having a rotation support portion as a main portion, and a second member joined to the first member and constituting a second groove portion and a fitting convex portion. For example, the counter pressure member can be configured easily and inexpensively, and for example, it can be configured such that only the second member that has a large amount of wear during processing can be replaced.

  Further, in the above-described pipe bending apparatus, a part of the fitting convex portion is positioned forward of the bending start position of the pipe in the advancing direction of the pipe, and the other part of the fitting convex portion is the pipe The structure located on the rear side with respect to the direction of movement of the pipe with respect to the bending start position, or the fitting portion of the fitting convex portion fitted in the fitting recess with respect to the bending start position of the pipe The contact portion between the first groove of the gripping member and the second groove of the counter pressure member, located on the front side in the pipe advancing direction, is on the rear side in the pipe advancing direction with respect to the pipe bending start position. If the configuration is positioned, smooth bending can be performed. Furthermore, if the bending die is composed of a plurality of members divided in a plane orthogonal to the central axis of the hollow shaft member, it can be manufactured with accuracy according to the function required for each part, The manufacture of each part becomes easy. In addition, for example, it is possible to easily change the stage only by the horizontal movement of the holding member and the hollow shaft member.

  Then, in each of the above-described pipe bending apparatuses, the tip portion is inserted into the pipe, and the core metal is driven so that the tip portion faces the pressure mold within a predetermined rotation range of the bending mold. Bending with a small bending radius can be easily performed, and the bending limit for the pipe can be greatly improved.

It is a perspective view showing a pipe bending apparatus concerning one embodiment of the present invention. It is a front view of the pipe bending type | mold unit which concerns on one Embodiment of this invention. It is a sectional view of a pipe bending type unit concerning one embodiment of the present invention. It is an exploded perspective view of a pipe bending type unit concerning one embodiment of the present invention. It is a cross-sectional perspective view which shows the state at the time of completion | finish of bending of the pipe bending apparatus which concerns on one Embodiment of this invention. It is the disassembled perspective view seen from the front side of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is the disassembled perspective view seen from the back side of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is the perspective view seen from the front side of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is the perspective view seen from the back side of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is a top view of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is sectional drawing of the pipe bending type | mold unit which concerns on other embodiment of this invention, and is the sectional view on the AA line of FIG. It is sectional drawing of the pipe bending type | mold unit which concerns on other embodiment of this invention, and is a BB sectional drawing of FIG. It is a disassembled perspective view of the pipe bending type | mold unit which concerns on another embodiment of this invention. It is a perspective view of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is a front view of the pipe bending type | mold unit which concerns on other embodiment of this invention. It is a perspective view which shows the pipe in which bending was performed using the pipe bending type | mold unit which concerns on embodiment of this invention. It is a perspective view showing one embodiment of a pipe bending apparatus equipped with a pipe bending type unit concerning an embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a pipe bending apparatus according to an embodiment of the present invention, and a pipe bending apparatus according to an embodiment including a gripping mold 200 and a pressure mold 300 in addition thereto. A bending die 100 having a pipe receiving groove (formed by first and second grooves 11 and 21 described later) having a semicircular cross-section on the outer peripheral surface and driven to rotate about a rotation axis (A) . Then, in the pipe bending apparatus, the pipe P to be processed is held between the bending mold 100 and the holding mold 200, and is advanced while being pressed in the bending mold 100 direction by the pressure mold 300, and the compression load and shaft The pipe P is configured to be bent by the pressing load.

  The bending die 100 according to the present embodiment includes the gripping member 10 and the counter pressure member 20, and as shown in FIGS. 1 and 2, the gripping member 10 is formed with a first groove 11 having a semicircular cross section. At the same time, a fitting recess 12 of a predetermined width is formed in the first groove portion 11 so as to extend a predetermined distance in the circumferential direction in a plane orthogonal to the rotation axis (A). The gripping member 10 is, as shown in FIGS. 3 and 4, via a sleeve 70 of a hollow shaft member having a large diameter portion and a small diameter portion, by means of a stud 60 of a fixed shaft member centered on the rotation shaft (A). It is fixed to a mounting base 13 (shown by a two-dot chain line in FIGS. 1 and 2) to be mounted. The stud 60 has a large diameter wedge-shaped engaging portion 60a formed at the middle portion thereof, and a screw portion 60b which is a fixed portion formed at the tip, and an axial portion 60c substantially coextensive with the screw portion 60b. The bolt 60 has a bolt shape and is accommodated in the axial opening 70 a of the sleeve 70, and the screw 60 b is screwed to the base 13 so that the stud 60 is fixed. Thus, the gripping member 10 and the counter-pressure member 20 are connected by hinged connection via the sleeve 70, and are supported by the stud 60 so as to be relatively rotatable about the rotation axis (A). The structure will be described in detail later. In addition, while the locking tool 80 is fixed to the holding member 10 and the knock pin 27 is fixed to the counter pressure member 20, these will also be described later.

  The holding member 10 has an annular recess 10b forming a first groove 11 having a semicircular cross section, as shown in FIG. 4, and extends in the circumferential direction in a plane orthogonal to the rotation axis (A) The fitting recess 12 has a predetermined width. The fitting recess 12 is disposed at the center of the bottom of the annular recess 10b. Therefore, the first groove portion 11 having a semicircular cross section includes a part of the fitting recess 12 and is continuous with the annular recess 10 b. That is, the holding member 10 of the present embodiment has a holding portion 10a for holding the pipe P (a bonding surface with the holding mold 200 is a flat surface) and an annular recess 10b continuously formed thereon, which are integrated Are formed. Thus, the first groove 11 is a continuous semicircular cross section of the groove 11a having a semicircular cross section formed in the grip 10a and the groove 11b having a semicircular cross section formed in the annular recess 10b. Have. In order to reliably grip the pipe P, a plurality of gripping strips may be provided in parallel in the circumferential direction on the inner side of the groove 11a.

  As shown in FIG. 3, the holding member 10 is formed with an axial opening 10 d that accommodates the engaging portion 60 a of the stud 60 and the large diameter portion of the sleeve 70, and accommodates the small diameter portion of the sleeve 70. An axial opening 10f is formed, and a step 10e is formed between the two. Furthermore, as shown in FIG. 4, the notch 10c is formed in the radial direction centering on the axis of the stud 60 and in the axial direction of the stud 60 in the gripping member 10, and communicates with the opening 10d. The notch 10c is set to a width exceeding the radial width (at least the width of the shaft 60c) of the stud 60, and in the present embodiment, from the radial direction centered on the axis of the stud 60 through the notch 10c. It is comprised so that the axial part 60c of the stud 60 may be accommodated. The notch 10c may be set to a width that can accommodate the engaging portion 60a and the shaft 60c of the stud 60, and may have a modified opening shape that can accommodate the engaging portion 60a and the shaft 60c, or It is good also as opening shape of equal width which can accommodate portion 60a. Further, the upper edge of the opening 10d is tapered, and the lower edge of the side face of the engaging portion 60a is tapered so that centering can be performed by fitting the two tapered portions. May be Furthermore, the width of the notch 10c may be set larger than the outer diameter of the engagement portion 60a.

  Similarly, as shown in FIG. 4, the sleeve 70 is formed with an axial opening 70 a that can receive the shaft 60 c of the stud 60, and the radial direction of the stud 60 and the A notch 70c is formed in the axial direction, and communicates with the opening 70a. The notch 70c is set to a width exceeding the radial width of the stud 60 (the width of the shaft 60c), and is configured to be able to receive the shaft 60c of the stud 60 via the notch 70c. The cutouts 10c and the cutouts 70c are not limited to the linear shape in the radial direction, and may have a combination of curves.

  Thus, the shaft portion 60c of the stud 60 is accommodated in the opening 70a through the notches 10c and 70c, and the stud 60 is attached to the gripping member 10 and the sleeve 70. In the present embodiment, the gripping member 10 and the sleeve 70 can be attached to the stud 60 in a state in which the screw portion 60 b is screwed (loosely) to the base 13 via the notches 10 c and 70 c. It is configured (this mounting operation is the same as the mode shown in FIG. 13 and will be described later). Furthermore, in the lower end surface of the holding member 10 and the upper end surface of the base 13, grooves 10g and 13g for inlay coupling are respectively formed in the radial direction, and the keys 13a and 13b (shown in FIG. 2) are between them. It is configured to be fitted and in-row coupled.

  On the other hand, as shown in FIG. 1 and FIG. 2, the second groove 21 having a semicircular cross section is formed in the outer peripheral surface of the counter pressure member 20, and the circumferential direction from the tip of the second groove 21 is The fitting convex portion 22 is formed to extend a predetermined distance at a predetermined distance, and when the fitting convex portion 22 is fitted to the fitting concave portion 12 described above, the first groove portion 11 of the gripping member 10 and the counter pressure member The 20 second groove portions 21 form a pipe receiving groove having a semicircular cross section. As shown in FIG. 4, the counter pressure member 20 comprises a C-shaped rotary support 23 rotatably supported by the stud 60 and having an opening having a width exceeding the radial width of the stud 60 in the radial direction. The rotation support portion 23 is rotatably supported by the sleeve 70 (and the stud 60) about a virtual rotation axis (A), and a part of the rotation support portion 23 constitutes the fitting convex portion 22 described above.

  Thus, in the present embodiment, C in the notches 10c and 70c and the counterpressure member 20 in a state in which the fitting convex portion 22 of the counterpressure member 20 is fitted in the fitting recess 12 of the gripping member 10. The stud 60 is fitted to each axial opening of the gripping member 10, the sleeve 70 and the counter pressure member 20 through the gap of the rotation support 23 of the letter shape, and the sleeve 70 is engaged with the engaging portion 60a and the step 10e. 1 to 3 becomes the holding unit 10, the sleeve relative to the stud 60 in which the screw portion 60b is screwed to the base 13. 70 and the counter pressure member 20 can be mounted. In this case, when the rotation support portion 23 of the counter pressure member 20 is fitted to the stud 60 (in other words, when the stud 60 is fitted to the rotation support portion 23), the unambiguous positioning between the two is achieved. To be done. The pressure member 20 may be configured as an annular member by joining a member that covers the gap of the C-shaped rotational support portion 23 after being connected to the stud 60.

  As shown in FIG. 4, the counter pressure member 20 of the present embodiment is rotatably supported (that is, rotated) on the curved surface portion (counter pressure portion) 20 a disposed to be able to abut on the annular recess 10 b and the sleeve 70. A C-shaped rotary support 23 pivotally supported about the axis (A) is provided, and a part of the rotary support 23 constitutes a fitting projection 22. Therefore, the outer peripheral surface of the rotation support portion 23 is formed to be a curved surface, and is configured to form a pipe receiving groove having a semicircular cross section together with the first groove portion 11 of the holding member 10. That is, the second groove 21 having a semicircular cross section is formed in the counter pressure member 20, and the end surface shape of the second groove 21 in contact with the first groove 11 of the holding member 10 corresponds to FIG. As shown by the contact portion (R), it is curved in a front view. The outer peripheral side surface of the fitting convex portion 22 is formed into a curved surface, and when the fitting convex portion 22 is fitted to the fitting concave portion 12 of the holding member 10, the semicircle of the first groove portion 11 of the holding member 10 A part of the cross section is formed, and both form a pipe receiving groove having a semicircular cross section.

  As shown in FIG. 4 (and FIG. 6), the antipressure member 20 of the present embodiment includes the first member 20x having the rotation supporting portion 23 as a main part, and the second groove 21 and the fitting that are joined thereto. A second member 20y constituting the convex portion 22 is divided into two parts, and only the second member 20y including a portion susceptible to wear can be replaced. Furthermore, the first member 20x is divided into a member including the main portion 23xa of the rotary support 23 and the joint 25 and a member including the auxiliary portion 23xb of the rotary support 23 and the support 26. A second member 20y consisting of a portion 23y of the rotation support portion 23 and the main body portion 24 constituting the fitting convex portion 22 is joined (for example, by a bolt). Thus, when the rotational support portion 23 of the counter pressure member 20 is fitted to the stud 60, a unique positioning is performed between the two, while when replacing the counter pressure member 20, the wear is large. Since only the second member 20y including the part 23y (the fitting convex portion 22) needs to be replaced, not only the replacement work becomes easy, but also the inexpensive counterpressure member 20 is used from the viewpoint of long-term use. It can be provided and cost down.

  As described above, as shown in FIGS. 1 and 2, the gripping member 10 and the counter-pressure member 20 are hinged about the rotation axis (A) (the central axes of the stud 60 and the sleeve 70) via the sleeve 70. The screw portion 60b of the stud 60 is screwed to the base 13, and the holding member 10 and the counter pressure member 20 are fixed to the base 13 in a relatively rotatably supported state. In the present embodiment, the gripping member 10 fixed to the base 13 is supported so as to be rotationally driven with respect to the counter pressure member 20 fixed to a predetermined position of a device (not shown). Then, the position where the locking tool 80 fixed at the predetermined position of the gripping member 10 abuts on the knock pin 27 fixed to the counter pressure member 20 is set as the initial relative position of the gripping member 10 and the counter pressure member 20 Is configured.

  As shown in FIG. 2, the gripping member 10 and the counter pressure member 20 are fitted with reference to a bending start position (indicated by a dashed dotted line S in FIG. 2) when bending the pipe P. A fitting portion with the fitting convex portion 22 not included in a plane orthogonal to the rotation axis (A) of the concave portion 12 (two planes including (H) shown in FIG. 2 and parallel to a plane perpendicular to the sheet of FIG. (F) is located on the front side (the right side of S in FIG. 2) of the advancing direction of the pipe P, and the rotational direction of the first groove 11 of the gripping member 10 and the second groove 21 of the counter pressure member 20 It is connected so that a contact part (R) may be located back side (left side of S in FIG. 2) with respect to the advancing direction of the pipe P. As shown in FIG. In other words, the fitting portion (F) in the rotational direction of the fitting convex portion 22 to be fitted in the fitting concave portion 12 is located forward of the bending processing start position of the pipe P in the advancing direction of the pipe P The contact portion (R) in the rotational direction between the first groove portion 11 of the gripping member 10 and the second groove portion 21 of the counter pressure member 20 corresponds to the rear in the advancing direction of the pipe P with respect to the bending start position of the pipe P Located on the side.

  Thus, as shown in FIG. 1 and FIG. 2, the pipe bending mold unit is constituted by the bending mold 100 in which the gripping member 10 and the counter pressure member 20 are arranged at the above-mentioned initial relative positions, If a plurality of pipe bending type units are prepared according to the shape of P, it is only necessary to select and replace the pipe bending type unit according to the shape when bending for various pipe shapes, so-called steps It can be easily replaced. In particular, as described above, since the initial relative positions of the gripping member 10 and the counter pressure member 20 can be set in advance by the locking tool 80 and the knock pin 27, no adjustment after the step change is necessary. It can be easily adjusted without the need. Furthermore, if the unit is configured to include the grip type 200 and the pressure type 300 in the above-described pipe bending type unit, it is possible to provide a pipe bending tool assembly that is easy to change and adjust.

  The entire operation of the pipe bending apparatus shown in FIG. 1 will first be described. First, in a state where the locking tool 80 is held at the initial relative position where it abuts the knock pin 27, the bending object portion of the body of the pipe P The same core metal (also referred to as a mandrel and indicated by M in FIG. 1) in the pipe P, which is disposed at the bending start position (S in FIG. 2) of the bending die 100, is inserted. The core metal M has ball cores M1 and M2 supported so as to be able to tilt at its tip as shown in FIG. 5 (however, hatching is omitted in consideration of visibility). Gold M 1 and M 2 are inserted into the pipe P and driven so as to be interposed between the bending die 100 and the holding die 200 and the pressure die 300 in a predetermined rotation range of the bending die 100. Next, the holding mold 200 and the pressure mold 300 are driven in the direction of the bending mold 100, and the tip of the pipe P is held between the holding member 10 of the bending mold 100 and the holding mold 200. Is pressed between the counter pressure member 20 of the bending die 100 and the pressure die 300.

  Subsequently, in a state where the tip of the pipe P is gripped between the gripping member 10 and the gripping mold 200, the pipe P is driven to be advanced while the body of the pipe P is pressed by the pressure mold 300 against the counterpressure member 20 When the holding mold 200 and the holding member 10 are rotationally driven about the rotation axis (A), the pipe P is sequentially moved to the pipe receiving grooves (first and second groove portions 11 and 21) of the bending mold 100. The pipe P which is bent to be wound and is bent as shown in FIG. 16 is formed. During this time, a large pressure is applied in the axial and radial directions of the pipe P. However, if the above-mentioned pipe bending type unit is used, the thickening by compressive deformation of the bending inner portion of the pipe P accompanying bending is controlled. The thickness of the bent outer portion of the pipe P can be increased, the thinning of the bent outer portion of the pipe P can be prevented, and the appropriate tube thickness can be maintained even at the bent portion.

  Thus, as shown in FIG. 16, the pipe P subjected to bending using the pipe bending type unit of the present embodiment corresponds to the fitting portion between the fitting recess 12 and the fitting projection 22. Although some thick parts (knob-like parts) are formed at the position, the part continuous with this becomes a smooth curved surface. Specifically, the thickness gradually changes in a portion shown by a thin line in FIG. 16 and the flowing wall is fitted into the fitting portion (F in FIG. 2) to form the thick portion TP1. Although thick portions TP2 and TP3 are formed along the contact portion (R in FIG. 2), portions shown by thin lines in FIG. 16 are formed to be smooth curved surfaces and do not correspond to so-called wrinkles. There is no need to worry about the occurrence of parts TP1, TP2 and TP3. Rather, the bent pipe in which these thick parts TP1, TP2 and TP3 are formed is a proof that bending is performed using the pipe bending unit of the present embodiment, and the processing quality is supported.

  As described above, the bending die 100 of the present embodiment includes the gripping member 10 and the counter pressure member 20, which are hinged about the central axis of the stud 60, that is, the rotation axis (A) via the sleeve 70. The pressure member 300 is pressed against the pressure mold 300 (via the pipe P) as the pipe P is bent, since the pipe P is connected so as to be relatively rotatably supported around the rotation axis (A). It can be rotated relative to the gripping member 10 about the rotation axis (A) in the set state. Accordingly, the gripping member 10 is rotationally operated in the circumferential direction away from the counter pressure member 20 from the bending processing start position (S in FIG. 2) with respect to the pipe P.

  Further, as described above, the gripping member 10 and the counter pressure member 20 are connected via the sleeve 70, and the level difference that may occur between the gripping member 10 and the counter pressure member 20 is suppressed to a small level. For this reason, even if a large axial load and compression load are applied to the pipe P in comparison with before, plastic deformation accompanying bending can be appropriately controlled. Moreover, when the gripping member 10 is rotationally driven with respect to the counter pressure member 20, torque due to relative rotation between the gripping member 10 and the counter pressure member 20 is not directly transmitted to the stud 60, via the sleeve 70. Rotate smoothly. As a result, the stud 60 screwed to the base 13 is not loosened (by so-called corotation), and a stable fixed state can be maintained.

  6 to 13 relate to another embodiment of the pipe bending type unit, and FIG. 6 and FIG. 7 are exploded perspective views, and the state after respective assembling is shown in FIG. 8 and FIG. And cross sections are shown in FIGS. 10-12. In the present embodiment, while the grip portion 10a (FIG. 4) described above is integrally formed on the grip member 10, the grip portion 10a portion is a separate body (shown by 10y in FIG. 6 etc.) It joins to the main body (it shows by FIG. 6 etc. with 10x) which comprises the recessed part 10b. In the present embodiment, the main body 10x is constituted by the upper mold 40 and the lower mold 50 divided in a plane orthogonal to the rotation axis (A), and a separate body 10y (constituting the grip portion 10a) is joined thereto The gripping member 10 described above is configured. That is, as shown in FIG. 6, the upper mold 40 and the lower mold 50 are respectively provided with the step 41, the opening 42, the step 51, and the opening 52, and the notches 40c and 50c. The upper die 40 and the lower die 50 are joined via the sleeve 70 so that these notches 40c, 50c and the notch 70c formed in the sleeve 70 match, and the separate member 10y of the gripping member is attached For example, it is configured to be bolted.

  In the separate member 10y of the holding member in this embodiment, the convex portions 10p and 10p are integrally juxtaposed on the back surface, and the convex portions 10p and 10p are respectively fitted in the long grooves 40d and 50d formed in the main body 10x. It is configured to be combined and fixed to the main body 10x. Thus, the groove portion 11a having a semicircular cross section formed in the grip portion 10a of the separate body 10y and the groove portion 11b having a semicircular cross section formed in the recess 10b of the main body 10x have a continuous semicircular cross section. The first groove portion 11 is configured. In addition, about the substantially same member as the above-mentioned embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Then, the sleeve 70 is interposed between the step 41 of the upper mold 40 and the step 51 of the lower mold 50 so that the notches 40c, 50c and 70c coincide (that is, in the same indexing position). The upper mold 40 and the lower mold 50 are joined via 70. Furthermore, the separate body 10y (the grip portion 10a) is fixed to the main body 10x (the upper mold 40 and the lower mold 50), and the stud 60 is accommodated through the notches 40c, 50c, 70c (in other words, the upper mold 40). , The lower mold 50 and the sleeve 70 are assembled to the stud 60), and when the stud 60 is tightened to the base 13, the state shown in FIGS. 8 and 9 is obtained.

  In the present embodiment, as shown in FIG. 12, the fitting convex portion 22 of the pressure member 20 is interposed between the upper die 40 and the lower die 50, but between the upper die 40 and the lower die 50. Is set to an appropriate value by the sleeve 70 described above, and since the clearance is not distorted even by the firm tightening to the base 13 by the stud 60, the fitting convexity between the upper mold 40 and the lower mold 50 is The smooth rotation operation of the portion 22 is ensured, and thus the smooth relative rotation of the gripping member 10 and the counter pressure member 20 is ensured.

  Further, as shown in FIGS. 6 and 7, the first member 20 x includes a member including the main portion 23 xa of the rotation support portion 23 and the joint portion 25, the auxiliary portion 23 x b of the rotation support portion 23, and the support portion 26. The two members are divided by the bolt connection between the joint portion 25 and the support portion 26, and the part 23y of the rotary support portion 23 (constituting the fitting convex portion 22) and the main body portion A second member 20y of 24 is configured to be joined to the first member 20x by bolting between the body portion 24 and the joint 25. Therefore, when replacing the counter pressure member 20, it is sufficient to replace only the second member 20y including the part 23y having a large amount of wear, the replacement operation is easy, and the cost is reduced. Moreover, since the joint portion 25 in the first member 20 x can be separated from the support portion 26, the upper mold 40, the lower mold 50 and the sleeve 70 remain assembled (the upper mold 40 and the lower mold 50 are separated And the second member 20y can be extracted horizontally, and the C-shaped rotation support portion 23 can be used to extract the member including the main portion 23xa of the rotation support portion 23 and the joint portion 25 and the second member 20y. If the configured air gap is small, replacement work can be performed particularly easily.

  Although the rotation support portion 23 may be integrally formed in a C-shape, in the present embodiment, since the main portion 23xa and the auxiliary portion 23xb are divided, they can be easily manufactured and the cost is reduced. be able to. Further, the space (the space between the main portion 23xa and the auxiliary portion 23xb) of the C-shaped rotation support portion 23 is sufficient for the portion supporting the portion 23y (the fitting convex portion 22) of the second member 20y. C, and the second member 20y may be set in a range that does not come off the sleeve 70 at the time of rotational driving, and a C-shape having a gap in the range of 180 ° or more on the circumference around the axis of the rotational support portion 23. It may be a shape. In other words, the main portion 23xa and the auxiliary portion 23xb shown in FIGS. 6 and 7 do not necessarily have to cover the range of 180 ° or more (on the circumference).

  At the time of stage change of the pipe bending type unit, the connection of the stud 60 to the base 13 by the screw portion 60b is loosened from the state of being mounted on the base 13 as shown in FIG. 8 and FIG. As shown in (A), a gap is generated between the engaging portion 60 a of the stud 60 and the upper mold 40. In this state, if the subassembly of upper die 40, lower die 50 and sleeve 70 is moved horizontally (in the direction shown by the white arrow in FIG. 13A), the subassembly is detached from stud 60, It will be in the state shown to (B) of FIG.

  Next, it is replaced with another subassembly (upper die 40, lower die 50 and sleeve 70), and is moved in the direction indicated by the outlined arrow in FIG. If the lower mold 50 and the sleeve 70 are attached to the stud 60 through the notches 40c, 50c and 70c, the state shown in FIG. 13A is obtained, and if the stud 60 is fastened to the base 13, FIG. It will be in the proper assembly state shown in. As described above, since the stage change can be performed only by the horizontal movement of the upper mold 40, the lower mold 50, and the sleeve 70, it is not necessary to lift a heavy load, and the workability is improved. Further, as a result, the weight reduction of the portions corresponding to the notches 40c, 50c, and 70c is also performed.

  Furthermore, as another embodiment, as shown in FIG. 14 and FIG. 15, the rotation axis (A) is centered in a form in which a plurality of bending dies 100a and 100b consisting of the above gripping member 10 and counter pressure member 20 are stacked. It can also be configured to be rotatably supported. Both the gripping members 10 and the counter pressure member 20 are connected by hinge connection via a sleeve (not shown) in the same manner as described above, and both of the bending dies 100a and 100b are as shown in FIGS. The main body 10x of the holding member configured by the upper mold and the lower mold similar to the mold 40 and the lower mold 50 is in a mode in which two layers are stacked.

  That is, the three members B1 to B3 (as well as the stud 60 and the sleeve) constitute the main bodies 10xa and 10xb of the two holding members, and the main body 10xa is the upper mold 401 (part of the member B1) and the lower mold 501 (member B2) The main body 10xb is constituted by the upper mold 402 (part of the member B2) and the lower mold 502 (part of the member B3), and the sleeve (not shown) as in the above embodiment. Is housed, and a notch (representatively represented by 100c) is formed.

  In addition, pins (not shown) are inserted in a state where the keys 45a and 45b are fitted in key grooves (references omitted) formed on opposite end surfaces of the upper molds 401 and 402 and the lower molds 501 and 502, respectively. The upper die 401, 402 and the lower die 501, 502 are joined via 45a and 45b and pins, and are configured to be bolted, for example. In addition, as shown in FIGS. 14 and 15, the holding tools 10ya and 10yb having different groove shapes according to the end shape of the object to be processed are joined to the main bodies 10xa and 10xb, respectively, and each holding member is configured. ing.

  Thus, since the two bending dies 100a and 100b are held with the sleeve (not shown) penetrating them and attached to the stud 60 through the notch 100c, positioning of both is easy. . In addition, since the respective clearances between the upper molds 401 and 402 and the lower molds 501 and 502 can be set to appropriate values by the above-mentioned sleeves, smooth rotation operation of the fitting convex portion 22 (gripping member as described above) The smooth relative rotation of 10 and the counter pressure member 20 is ensured.

  The pipe bending apparatus 1 to which the pipe bending type unit of each of the above embodiments is attached is configured as shown in FIG. 17, for example, and provided with a pipe chuck CH for gripping a pipe P to be processed, and advancing the pipe P A carriage CR is provided to drive and apply an axial pressing load. By rotationally driving (indexing) the pipe chuck CH, the bending direction of the pipe P can be changed, which enables three-dimensional bending. In addition, the grip mold 200 is disposed on the rotary table 2 and is configured to be rotationally driven about the rotation axis (A) (the central axis of the stud 60 shown in FIG. 17).

  In this pipe bending apparatus 1, similarly to the pipe bending unit shown in FIGS. 14 and 15, for example, the three gripping members 10 and the counter pressure member 20 are relatively driven to rotate via the sleeve 70 described above. The pipe bending unit (designated by DU in FIG. 17) is fixed to the base 13 by means of the studs 60. The center of the stud 60 (and the sleeve 70 described above) is formed by connecting and supporting the three holding members 10 shown in FIG. 17 and the connecting and supporting member 92 connecting and supporting the three counter pressure members 20. It is rotationally driven around an axis, and the relative movement of the gripping member 10 and the counter pressure member 20 is controlled. Note that, in FIG. 17, the connection support member 92 is connected to the drive device DR via the link 93, and the three counter pressure members 20 are configured to move at the same time. The pressure members 20 may be separately driven and controlled.

DESCRIPTION OF SYMBOLS 10 gripping member 11 1st groove part 12 fitting recessed part 13 base 20 counter pressure member 20x 1st member 20y 2nd member 21 2nd groove part 22 fitting convex part 23 rotation support part 27 knock pin 40 upper mold | type 50 lower Model 60 stud (fixed shaft member)
70 sleeve (hollow shaft member)
80 Locking tool 100 Bending type 200 Gripping type 300 Pressure type A Rotation axis P pipe

Claims (13)

It has a bending die that has a pipe receiving groove with a semicircular cross section on the outer peripheral surface and is rotationally driven around the rotation axis,
The bending mold is
A fitting recess having a first groove with a semicircular cross section on the outer peripheral surface and being formed in the first groove and extending a first predetermined distance in a circumferential direction in a plane orthogonal to the rotation axis A gripping member having
A second groove having a semicircular cross section on the outer peripheral surface, and a fitting protrusion extending a second predetermined distance in the circumferential direction from the tip of the second groove, the fitting protrusion being A counter pressure member that fits into the fitting recess and joins the first groove and the second groove to form a pipe receiving groove having a semicircular cross section;
A hollow shaft member having the rotation axis as a central axis and rotatably supporting the gripping member and the counter pressure member;
A fixed shaft member which is accommodated in the hollow shaft member and has an engaging portion engaged with the hollow shaft member, and has a fixing portion at least at one end,
A notch with at least the gripping member and the hollow shaft member formed in the radial direction about the axis of the fixed shaft member and in the axial direction of the fixed shaft member and exceeding the radial width of the fixed shaft member And the fixed shaft member is mounted through the notch portion, and
A pipe bending unit in which the counter pressure member and the gripping member are connected by hinge connection via the hollow shaft member and supported so as to be relatively rotatable about the rotation shaft. The counter pressure member has a C-shaped rotary support portion rotatably supported by the hollow shaft member and having an opening having a width exceeding the radial width of the fixed shaft member in the radial direction;
The pipe according to claim 1, wherein a part of the rotation support portion constitutes the fitting convex portion, and an outer peripheral surface of the rotation support portion is a curved surface forming a part of the pipe receiving groove having a semicircular cross section. Bending type unit. The counter pressure member includes a first member having the rotation support portion as a main portion, and a second member joined to the first member and constituting the second groove portion and the fitting convex portion. The pipe bending unit according to claim 2. A part of the fitting convex portion is located on the front side in the advancing direction of the pipe to be processed with respect to the bending start position of the pipe, and the other part of the fitting convex portion starts the bending of the pipe The pipe bending unit according to any one of claims 1 to 3, which is located rearward with respect to the position with respect to the traveling direction of the pipe. The fitting portion of the fitting convex portion to be fitted to the fitting recess is located forward of the bending start position of the pipe to be processed in the advancing direction of the pipe, and the first portion of the holding member is The contact part of the groove part of the said, and the said 2nd groove part of the said pressure | pressure-supply member is located in the back side of the advancing direction of the said pipe with respect to the bending process start position of the said pipe. Pipe bending unit according to one aspect. The pipe bending die unit according to any one of claims 1 to 5, wherein the bending die comprises a plurality of members divided in a plane orthogonal to the central axis of the hollow shaft member. A bending die having a pipe receiving groove with a semicircular cross section on the outer peripheral surface and driven to rotate about a rotation axis;
A gripping type for gripping a pipe to be processed which is disposed in a pipe receiving groove of the bending type;
A pressure die for pressing the pipe in the bending die direction;
The bending mold is
A fitting recess having a first groove with a semicircular cross section on the outer peripheral surface and being formed in the first groove and extending a first predetermined distance in a circumferential direction in a plane orthogonal to the rotation axis A gripping member having
A second groove having a semicircular cross section on the outer peripheral surface, and a fitting protrusion extending a second predetermined distance in the circumferential direction from the tip of the second groove, the fitting protrusion being A counter pressure member that fits into the fitting recess and joins the first groove and the second groove to form a pipe receiving groove having a semicircular cross section;
A hollow shaft member having the rotation axis as a central axis and rotatably supporting the gripping member and the counter pressure member;
A fixed shaft member which is accommodated in the hollow shaft member and has an engaging portion engaged with the hollow shaft member, and has a fixing portion at least at one end,
A notch with at least the gripping member and the hollow shaft member formed in the radial direction about the axis of the fixed shaft member and in the axial direction of the fixed shaft member and exceeding the radial width of the fixed shaft member And the fixed shaft member is mounted through the notch portion, and
Pipe bending apparatus in which the counter pressure member and the gripping member are connected by hinged connection via the hollow shaft member, and relatively rotatably supported around the rotation shaft to constitute a pipe bending type unit . The counter pressure member has a C-shaped rotary support portion rotatably supported by the hollow shaft member and having an opening having a width exceeding the radial width of the fixed shaft member in the radial direction;
The pipe according to claim 7, wherein a part of the rotation support portion constitutes the fitting convex portion, and the outer peripheral surface of the rotation support portion is a curved surface forming a part of the pipe receiving groove having a semicircular cross section. Bending machine. The counter pressure member includes a first member having the rotation support portion as a main portion, and a second member joined to the first member and constituting the second groove portion and the fitting convex portion. The pipe bending apparatus according to claim 8. A portion of the fitting projection is located forward of the bending start position of the pipe in the advancing direction of the pipe, and the other portion of the fitting projection is at the bending start position of the pipe The pipe bending apparatus according to any one of claims 7 to 9, wherein the pipe bending apparatus is positioned on the rear side with respect to the traveling direction of the pipe. The fitting portion of the fitting convex portion to be fitted to the fitting recess portion is located forward of the bending start position of the pipe in the advancing direction of the pipe, and the first groove portion of the holding member 10. The contact portion between the first and second groove portions of the counter pressure member according to any one of claims 7 to 9, which is located on the rear side in the advancing direction of the pipe with respect to the bending start position of the pipe. Pipe bending apparatus according to claim 1. The pipe bending apparatus according to any one of claims 7 to 11, wherein the bending die comprises a plurality of members divided in a plane orthogonal to the central axis of the hollow shaft member. The tip according to any one of claims 7 to 12, further comprising a core metal inserted into the pipe and driven so that the tip faces the pressure die within a predetermined rotation range of the bending die. Pipe bending apparatus as described.

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