JP2012076222A - Method and device for manufacturing pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pipe, capable of preventing damaging of a raw pipe surface due to inclusion of burrs or chips during correcting work by rolls.SOLUTION: This method for manufacturing the pipe includes a pipe end cutting-off process of cutting off at least one end part 2 out of both end parts of a raw pipe 1 provided by drawing, and a roll correcting proceeding process of applying roll correcting processing on the raw pipe 1 passed through the pipe end cutting-off process. An outer diameter of the raw pipe is set in a range of 12-50 mm. A thickness of the raw pipe is set in a range of 0.5-1.5 mm. In the pipe end cutting-off process, an end part 2 of the raw pipe 1 is cut off by sending one or a plurality of freely rotatable disk-like cutting blades 15 arranged in a plane vertical to the axis of the raw pipe 1 on the outside of the end part 2 of the raw pipe 1, to the inside of the raw pipe 1 while relatively moving to the raw pipe 1 in the peripheral direction of the raw pipe 1.

Description

  The present invention relates to a method for manufacturing a pipe such as a precision pipe and a pipe manufacturing apparatus.

  For example, a photosensitive drum base for supporting a photoconductive photosensitive layer such as selenium or an organic photosensitive member in a photosensitive drum of an electronic copying machine or a laser printer is formed from a metal pipe such as aluminum (including its alloy). Has been. This pipe is required to have high dimensional accuracy (eg, straightness) and high surface (outer peripheral surface) accuracy in order to obtain a high-quality image.

  By the way, in many cases, this pipe is manufactured from a raw tube obtained by drawing, but such a raw tube is bent not a little by non-uniformity of internal stress generated at the time of drawing. There are many cases. In view of this, roll straightening is applied to the raw tube in order to improve straightness.

  When this roll straightening is performed, if foreign matter such as chips or dirty oil adheres to the end of the raw tube, the foreign matter is between the straightening roll and the surface (outer peripheral surface) of the raw tube. As a result, the surface of the raw tube is damaged. In particular, when the tube is a tube of a photosensitive drum base pipe that requires high surface (outer peripheral surface) accuracy, this scratch becomes a fatal surface defect, and the yield of the product during the production of the photosensitive drum is increased. Decreases.

  Therefore, conventionally, in order to solve this problem, first, an end portion of the raw tube is cut out, and then roll correction processing is performed on the raw tube (see, for example, Patent Document 1). Further, in this case, the end portion (tube end) of the element tube is excised by feeding a cutting blade (shearing blade) linearly across the element tube using a press cutting device.

Japanese Patent Laid-Open No. 3-184623 (Claim 1, FIG. 1 (c))

  Thus, when the end portion of the pipe is cut by the conventional cutting method, the cutting blade (specifically, the cutting edge of the cutting blade) at the cutting portion of the pipe advances from the outer peripheral surface of the raw tube to the inner peripheral surface. As the cutting blade advances, inward burrs are generated in the cut part, but the cutting blade in the cutting part of the raw tube advances from the inner peripheral surface of the raw tube to the outer peripheral surface and is cut. As the cutting blade advances, an outward burr is generated in the part. In particular, if the management state of the cutting blade is poor, the size and the amount of burrs increase.

  Thus, when an outward burr | flash generate | occur | produces in the cutting part of an element pipe, the same problem as the above occurs. That is, during the roll straightening process, the burr is scraped off by the straightening roll, and the burr is caught between the straightening roll and the surface of the blank tube, resulting in a problem that the surface of the blank tube is damaged. To do.

  Conventionally, cutting of the tube end has been performed by a press cutting method using a cutting blade (shearing blade) consisting of a parting blade, so that the cutting portion of the raw tube is deformed into a flat shape upon receiving cutting force at the time of cutting. For example, the cut portion of the base tube may be locally deformed. When the cut portion of the raw tube is deformed in this way, it becomes difficult to improve the straightness at the time of roll straightening.

  The present invention has been made in view of the above-described technical background, and its purpose is to manufacture a pipe that can prevent the surface of the raw tube from being damaged by burrs or chips during roll straightening, and thus manufactured. Another object of the present invention is to provide a pipe manufacturing apparatus suitably used in the pipe manufacturing method.

  The present invention provides the following means.

  [1] A tube end excision step of excising at least one end portion of both ends of the element tube obtained by drawing, and a roll correction process step of performing roll correction processing on the element tube that has undergone the tube end excision step In the pipe end cutting step, one or a plurality of rotatable disk-shaped members arranged in a plane perpendicular to the axis of the raw tube outside the end of the raw tube A method for manufacturing a pipe, comprising cutting an end portion of a raw pipe by sending a cutting blade to the inside of the raw pipe while moving the cutting blade relative to the raw pipe in the circumferential direction of the raw pipe.

  [2] The method for manufacturing a pipe according to item 1, wherein a tip angle of the cutting blade is set in a range of 30 to 80 °.

  [3] The number of the cutting blades is three, and these three cutting blades are arranged on the outer side of the end portion of the raw tube, in a plane perpendicular to the axis of the raw tube, and spaced in the circumferential direction of the raw tube. 3. The method for producing a pipe according to 1 or 2 above.

  [4] The tube end excision step according to any one of items 1 to 3, wherein the revolution number of the cutting blade around the element tube is set in a range of 400 to 800 rpm and the end of the element tube is excised. Pipe manufacturing method.

  [5] In the tube end excision step, any one of items 1 to 4 above, wherein the cutting blade feed speed is set in a range of 0.5 to 1.5 m / min and the end portion of the raw tube is excised. The manufacturing method of the pipe of description.

  [6] In the tube end excision step, after performing an operation of feeding the cutting blade to the inside of the raw tube, the end portion of the raw tube is excised, and then the feed operation is continued. A method for producing a pipe according to claim 1.

  [7] In the tube end excision step, after performing the feed operation of sending the cutting blade to the inside of the raw tube, the end portion of the raw tube is cut off, and then this feed operation is continued with a feed amount of 0.5. The method for producing a pipe according to any one of the preceding items 1 to 5, which is carried out by setting it in a range of ˜2.5 mm.

  [8] The method for manufacturing a pipe according to any one of items 1 to 7, wherein the pipe is a precision pipe.

  [9] The method for manufacturing a pipe according to any one of items 1 to 7, wherein the pipe is a pipe for a photosensitive drum substrate.

  [10] A pipe manufactured by the method for manufacturing a pipe according to any one of items 1 to 9.

  [11] A tube end excision device that excises at least one end of both ends of the element tube obtained by the drawing process, and roll correction processing is performed on the element tube whose end is excised by the tube end excision device. A pipe straightening device, wherein the pipe end excision device is arranged in a plane perpendicular to the axis of the raw pipe outside the end of the raw pipe to be cut or A plurality of rotatable disc-shaped cutting blades are provided, and the cutting blades are configured to be sent from the outside to the inside of the element tube while being moved relative to the element tube in the circumferential direction of the element tube. An apparatus for manufacturing a pipe, characterized by comprising:

  [12] The pipe manufacturing apparatus according to [11], wherein a tip angle of the cutting blade is set in a range of 30 to 80 °.

  [13] The number of the cutting blades is three, and these three cutting blades are arranged on the outer side of the end portion of the raw tube at a distance in the circumferential direction of the raw tube in a plane perpendicular to the axis of the raw tube. 13. The pipe manufacturing apparatus according to 11 or 12 above.

  [14] The pipe manufacturing apparatus according to any one of the above items 11 to 13, wherein the pipe is a precision pipe.

  [15] The pipe manufacturing apparatus according to any one of the above items 11 to 13, wherein the pipe is a pipe for a photosensitive drum base.

  The present invention has the following effects.

  According to the invention of [1], in the tube end excision step, one or a plurality of rotatable disc-shaped cutting blades arranged in a plane perpendicular to the axis of the tube outside the end of the tube. Since the end of the pipe is cut by sending the pipe to the inside of the pipe while moving relative to the pipe in the circumferential direction of the pipe, the entire circumference of the cut portion of the pipe is No outward burrs are generated, and almost no chips are generated during excision. Therefore, by performing roll correction processing on the element tube whose end has been cut in this way, it is possible to prevent the element tube surface from being damaged by burrs and chips, and to obtain a pipe having high surface accuracy. it can. Moreover, the deformation | transformation of the cutting | disconnection part of the raw tube which may arise at the time of excision can be prevented. Further, the cut portion of the raw tube can be processed to be rounded inward. Therefore, the raw tube can be smoothly put into the roll straightening apparatus, and the flare of the pipe can be reduced after the roll straightening process to improve the product yield.

  According to the invention of [2], since the tip angle of the cutting blade is set within a predetermined range, generation of burrs and chips can be reliably prevented, and the cut portion of the raw tube can be surely rounded. Can be processed.

  According to the invention of [3], the number of cutting blades is three, and these three cutting blades are arranged in the circumferential direction of the raw tube within a plane perpendicular to the axis of the raw tube outside the end of the raw tube. By being arranged at intervals, the end of the blank tube can be gripped by these three cutting teeth at the start of tube end resection. Therefore, the tube end excision work can be efficiently performed.

  According to the invention of [4], the above effect can be surely obtained by setting the revolution number of the cutting blade around the element tube to a predetermined range and cutting the end of the element tube.

  According to the invention of [5], the above-mentioned effect can be surely produced by setting the feed rate of the cutting blade within a predetermined range and cutting the end of the raw tube.

  According to the invention of [6], the above-described effect can be obtained by performing the feed operation for feeding the cutting blade to the inside of the blank tube, and then performing the feed operation after the end of the blank tube is excised. It can be played reliably.

  According to the invention of [7], after performing the feed operation for sending the cutting blade to the inside of the raw tube, the end portion of the raw tube is excised, and then the feed operation is set to a predetermined range. By doing so, the above-described effects can be achieved more reliably.

  According to the invention of [8], a precision pipe can be manufactured.

  According to the invention of [9], a pipe for a photosensitive drum substrate can be manufactured.

  According to the invention of [10], a pipe having high surface accuracy can be provided.

  According to the inventions [11] to [15], a pipe manufacturing apparatus that can be suitably used in the pipe manufacturing method according to the present invention can be provided.

It is a figure for demonstrating the manufacturing method of the pipe which concerns on 1st Embodiment of this invention, and is a partial cross section side view of the raw pipe which shows the drawing process performed about the raw pipe of the pipe. It is the whole element tube side view. (A) is a side view of the tube end excision apparatus which concerns on 1st Embodiment of this invention, (b) is a front view of a tube end excision apparatus. (A) is a side view of the cutting blade of a tube end excision apparatus, (b) is a front view of a cutting blade. (A) is a side view of the tube end excision device at the time of excision, and (b) is a front view of the tube end excision device as seen from line XX in (a). It is an expanded side view of the cutting part of the element tube after excision. It is the whole elementary tube side view after excision. (A) is a side view of the roll straightening apparatus showing a state at the start of straightening, and (b) is a side view of the roll straightening apparatus showing a state during the straightening. (A) is a side view of the tube end excision apparatus which concerns on 2nd Embodiment of this invention, (b) is a front view of the tube end excision apparatus seen from the XX line in (a). It is a figure (graph) which shows the incidence rate of the surface defect of the pipe of Example 36 (this invention), and the incidence rate of the surface defect of the pipe of the comparative example 1 (conventional example). (A) is an overall side view of the pipe used in Example 37 and Comparative Example 2, (b) is a diagram (graph) showing the measurement result of flare in Example 37, and (c) is the flare of Comparative Example 2. It is a figure (graph) which shows a measurement result.

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

  1 to 8 are diagrams for explaining a pipe manufacturing method and a pipe manufacturing apparatus according to the first embodiment of the present invention.

  The pipe manufactured by the pipe manufacturing method according to the present embodiment is a precision pipe, and more specifically, a pipe used for a base of a photosensitive drum mounted on an electronic copying machine, a laser printer, a FAX apparatus, or the like, that is, a photosensitive pipe. This is a drum base pipe.

  In FIG. 2, (1) is a base pipe of the pipe for the photosensitive drum base. This base pipe (1) has a circular cross section, and is a long product made of aluminum (including its alloy; the same applies hereinafter) obtained by drawing using a draw bench as a drawing device (40). It consists of a non-cutting drawn tube. Of the two end portions of the base tube (1), one end portion (2) is formed with a mouthpiece (2a). As shown in FIG. 1, the mouth-attaching portion (2 a) passes the end portion of the raw pipe (1) through the forming hole (41 a) of the drawing die (41) of the drawing device (40) during drawing. Therefore, it is formed by subjecting the end portion of the raw tube (1) to a reduction processing (for example, swaging processing). At the time of drawing, the opening (2a) is passed through the forming hole (41a) of the drawing die (41) and then chucked by the chuck portion (43) of the carriage (42). And an element pipe (1) is obtained by drawing in this chuck state. In FIG. 1, (44) is a plug, and (45) is its support bar.

  In the present invention, the element tube (1) is not limited to the one made of aluminum, but may be made of another metal or other material. Moreover, the raw tube (1) is not limited to that obtained by drawing using a draw bench, and may be obtained by drawing using another drawing apparatus.

  In the present embodiment, both ends (2) and (2) of the raw tube (1) are excised (cut and removed) by the tube end excision device (10) of the first embodiment of the present invention shown in FIG. [Tube end excision step]. In FIG. 2, (L) is a planned cutting line of the end (2) of the raw tube (1). Next, the straight pipe (1) is subjected to roll straightening for bending correction by the roll straightening apparatus (20) according to the first embodiment of the present invention shown in FIG. 8 [roll straightening process]. . The desired pipe (5) is manufactured through the above steps. Therefore, the pipe manufacturing apparatus (30) of the present embodiment includes the pipe end cutting apparatus (10) and the roll straightening apparatus (20), and the pipe (5) desired by the pipe manufacturing apparatus (30) is obtained. Manufactured.

  First, the configuration of the tube end resection device (10) will be described below.

  As shown in FIGS. 3 (a) and 3 (b), the tube end excision device (10) includes a rotating body (11) that is driven to rotate by a drive motor (not shown), and three rotatable discs. And a cutting blade (15).

  The rotating body (11) is for moving (revolving) the cutting blade (15) in the circumferential direction of the end (2) of the raw tube (1). At the center of rotation of the front surface of the rotating body (11), a circular tube-shaped insertion hole (12) into which the end (2) of the raw tube (1) to be cut is inserted extends in the direction of the rotation axis. Is provided.

  In addition, three cutting blade support members (13) are arranged at equal intervals in the circumferential direction around the raw tube insertion hole (12) on the front surface of the rotating body (11), and the raw tube insertion hole ( 12) is provided so as to be slidable in the radial direction of the end portion (2) of the raw tube (1) to be inserted into 12). Each cutting blade support member (13) is slid by receiving a driving force from a driving source (not shown). As the drive source, a motor, a fluid pressure cylinder (eg, hydraulic cylinder, gas cylinder), or the like is used.

  The cutting blade (15) is rotatably supported by a corresponding cutting blade support member (13) via a support shaft (14). In this way, the three cutting blades (15) are perpendicular to the axis of the tube (1) outside the end (2) of the tube (1) inserted into the tube insertion hole (12). It arrange | positions at equal intervals in the circumferential direction of a raw pipe | tube (1) in the surface. The cutting blade support member (13) is slid in the radial direction of the raw tube (1) toward the center of the raw tube (1), so that the cutting blade (15) is moved to the end of the raw tube (1) ( 2), the cutting blade (15) is sent in the radial direction of the raw tube (1) toward the center of the end (2) of the raw tube (1). Yes. Furthermore, by rotating the rotating body (11), the cutting blade (15) is moved (revolved) in the circumferential direction of the end (2) of the raw tube (1). Note that the cutting blade (15) is rotatably supported as described above, that is, is not driven to rotate.

  As shown in FIGS. 4 (a) and 4 (b), the cutting blade (15) has a disk shape in which cutting edges (16) (cutting edges) are formed on the entire periphery. The cutting blade (16) of the cutting blade (15) is composed of a double blade having blade surfaces (16a) and (16a) formed on both surfaces thereof. As shown to Fig.4 (a), it is desirable for the front-end | tip angle (alpha) of the cutting blade (15) to be set to the range of 30-80 degrees, and it is especially set to the range of 45-70 degrees. desirable. The reason for this will be described later.

  Examples of the material of the cutting blade (15) include tool steel, cemented carbide tool steel, ceramic, diamond and the like. The magnitude | size of a cutting blade (15) is suitably selected according to the diameter and thickness of a raw tube (1). For example, the diameter of the cutting blade (15) is set in the range of 50 to 100 mm, and the thickness of the cutting blade (15) is set in the range of 2 to 20 mm. However, in the present invention, the diameter and thickness of the cutting blade (15) are not limited to such ranges.

  Next, the configuration of the roll straightening device (20) will be described below.

  As shown in FIG. 8, the roll straightening device (20) is a so-called inclined roll type straightening device that has been conventionally used. That is, the roll straightening device (20) includes, as its basic structure, straightening rolls (21) arranged in a plurality of slanted states such as a zigzag or a drum shape. In this roll straightening device (20), the raw pipe (1) is drawn by the action of the straightening roll (21) by passing the raw pipe (1) between the straightening rolls (21) from its end, The tube (1) is straightened while imparting follower rotation, and is fed forward.

  Next, a method for manufacturing a pipe using the pipe end cutting device (10) and the roll straightening device (20) will be described below.

  First, as the raw pipe (1), as shown in FIG. 2, a pipe made of the above-described long non-cutting drawn pipe made of aluminum is prepared. For example, the length of the raw tube (1) is set in the range of 4 to 10 m, the outer diameter is set in the range of 12 to 50 mm, and the wall thickness is set in the range of 0.5 to 1.5 mm. ing. Furthermore, a mouth piece (2a) is formed at one end (2) of the both ends of the base tube (1).

  In order to cut off the end (2) including the mouthpiece (2a) of the raw tube (1), as shown in FIG. 5, the end (2) of the raw tube (1) is removed from the tube end cutting device (10). Insert the tube into the tube insertion hole (12). Then, the pipe (1) is fixed by a fixture (not shown) so that the pipe (1) does not rotate on its own axis. Next, the three cutting blades (15) are slid in the radial direction of the raw pipe (1) toward the center of the end (2) of the raw pipe (1) by three cutting blade support members (13). ) Against the outer peripheral surface of the end (2) of the base tube (1). Thereby, the edge part (2) of an elementary pipe (1) is hold | gripped with three cutting blades (15). By gripping the end (2) of the raw tube (1) in this way, the tube end excision work can be efficiently performed.

  Next, the cutting blade support member (13) is moved while the cutting blade (15) is moved (revolved) in the circumferential direction of the end (2) of the raw tube (1) by rotating the rotating body (11). The cutting blade (15) is slid toward the center of the end (2) of the tube (1) to move the cutting blade (15) from the outside to the inside of the end (2) of the base tube (1). Is sent in the radial direction of the end (2) of the pipe (1) toward the center of the end (2) of the pipe (1). By this feeding operation, the peripheral wall portion of the end portion (2) of the raw tube (1) is sheared by the cutting blade (15) over the entire circumference, so that the end portion (2) of the raw tube (1) is cut off. . FIG. 6 is an enlarged side view of the cut portion of the blank tube (1) after excision.

  By cutting the tube end as described above, outward burrs are generated around the entire circumference of the cut portion of the raw tube (1), and generation of chips during cutting is prevented. Therefore, no chips adhere to the raw tube (1). Furthermore, it is possible to prevent deformation of the cut portion of the raw tube (1) that may occur during excision. Furthermore, as shown in FIG. 6, the cut portion of the raw tube (1) can be processed to be rounded inward. (3) in the figure is an inwardly rounded portion formed in the cut portion of the raw tube (1). K is the rounding amount of the rounded portion (3) with respect to the outer peripheral surface of the raw tube (1).

  Further, after cutting off the end (2) of the tube (1) in this way, the feed operation for continuously feeding the cutting blade (15) to the inside of the end (2) of the tube (1). It is desirable to perform a feed operation in which 15) is sent in the radial direction of the end (2) of the raw tube (1) toward the center of the end (2) of the raw tube (1). By doing so, it is possible to reliably prevent the occurrence of outward burrs, and to reliably process the cut portion of the raw tube (1) inwardly. In the subsequent feeding operation of the cutting blade (15), it is desirable to set the feed amount in the range of 0.5 to 2.5 mm.

  Furthermore, it is desirable that the tip angle α of the cutting blade (15) is set in the range of 30 to 80 ° as described above. By setting α within this range, the generation of burrs and chips can be prevented more reliably, and the cut portion of the raw pipe (1) can be further rounded. In particular, α is preferably set in the range of 45 to 70 °.

  Furthermore, in the tube end cutting step, it is desirable to set the revolution number around the raw tube of the cutting blade (15) in the range of 400 to 800 rpm (particularly preferably 500 to 700 rpm).

  Furthermore, it is desirable to set the feed rate of the cutting blade (15) in the range of 0.5 to 1.5 m / min.

  Next, the other end (2) of the element tube (1) is excised by the same excision method as described above using the tube end excision device (10). Thereby, as shown in FIG. 7, the elementary tube (1) from which both ends were excised is obtained.

  Next, as shown in FIG. 8, this straight pipe (1) is subjected to roll straightening by a roll straightening apparatus (20) to correct the bending of the straight pipe (1) and improve straightness. This correction method will be described below.

  That is, as shown in FIG. 8 (a), the raw pipe (1) is inserted into the roll straightening device (20) from one end (2) and passed between the plural straightening rolls (21). Thus, the straight tube (1) is straightened while the driven tube (1) is pulled by the action of the straightening roll (21) and the driven rotation is applied. The straightened tube (1) is fed forward as shown in FIG. 8 (b). Thus, the desired pipe (5) is manufactured by performing roll correction | amendment processing over the full length about an elementary pipe (1). In addition, the arrow Z in the figure has shown the injection | throwing-in direction to the roll straightening apparatus (20) of a raw pipe (1).

  At the time of this roll straightening process, as described above, no outward burrs are generated in the cut portion of the raw tube (1), and no chips adhere to the raw tube (1). The surface (outer peripheral surface) of the raw tube (1) is not damaged by burrs or chips. Therefore, the pipe (5) having high surface accuracy can be manufactured.

  Note that inward burrs are generated at the cut portion of the tube (1), but these burrs are not in direct contact with the straightening roll (21), so this burr is scraped off by the straightening roll (21). It will never be. Therefore, in the inward burrs, the surface of the raw pipe (1) due to the burrs is hardly damaged.

  Further, as described above, since the cut portion of the raw pipe (1) is rounded inwardly, the raw pipe (1) can be smoothly put into the roll straightening device (20) and the work can be performed. Efficiency is improved. Furthermore, the flare of the pipe (5) can be reduced after the roll straightening process, the yield of the product can be improved, and the undulation of the pipe (5) can be reduced.

  Next, if necessary, the pipe (5) is cut into a plurality of pieces in the length direction corresponding to the photosensitive drum base (pipe product). The pipe cut product thus obtained is used as a pipe for a photosensitive drum substrate.

  FIG. 9 is a view for explaining a tube end cutting device in a pipe manufacturing apparatus according to a second embodiment of the present invention.

  The tube end excision device (10A) of the present embodiment includes a rotation driving means (17) for rotating the raw tube (1) by its own axis. In the present embodiment, an annular rotation drive member (18) driven by a drive motor (not shown) is provided as the rotation drive means (17). The rotation drive means (17) is a member that rotates the element tube (1) by rotating the rotation drive member (18) by mounting the rotation drive member (18) on the element tube (1). It has been. In the present invention, the rotation driving means (17) may have other configurations. For example, the rotation driving means (17) is in contact with the outer peripheral surface of the element pipe (1) and rotates the element pipe (1) by its own axis. It may be composed of a roller, or may be composed of a chuck device that can be rotationally driven to rotate the base tube (1) with the end (2) of the base tube (1) chucked. Other configurations of the tube end resection device (10A) are the same as those of the tube end resection device (10).

  In the tube end excision step using this tube end excision device (10A), the cutting blade (15) is rotated while rotating the base tube (1) by the rotation drive means (17) without rotating the rotating body (11). ) Is sent from the outside to the inside of the tube (1) to cut off the end (2) of the tube (1).

  As mentioned above, although several embodiment of this invention was described, this invention is not limited to what was shown to the said embodiment, A setting change is variously possible.

  For example, in the pipe end cutting device (10) of the pipe manufacturing apparatus according to the present invention, the number of cutting blades (15) may be one, two, or four or more. There may be. In the tube end excision step, only one end (2) of both ends of the raw tube (1) may be excised.

  Further, the pipe (5) manufactured by the pipe manufacturing method according to the present invention is not limited to the pipe for the photosensitive drum base, and for example, high surface (outer peripheral surface) accuracy and high straightness are required. Further, it may be a precision pipe such as a barrel pipe of an optical device (eg, camera).

  Next, specific examples and comparative examples of the present invention will be shown.

<Examples 1-7>
An element tube (1) obtained by drawing and having a mouthpiece (2a) formed at one end (2) was prepared. This raw tube (1) has an outer diameter of 24 mm and a wall thickness of 0.7 mm. Next, the end portion (2) of the raw tube (1) was excised using the tube end excision device (10) of the first embodiment. Table 1 shows the tip angle α of the cutting blade (15) of the tube end cutting device (10) used in this cutting step. And while evaluating the generation | occurrence | production amount of the outward burr | flash produced in the cutting | disconnection part of a raw pipe (1), and the generation amount of a chip | tip, the round part formed in the cutting | disconnection part of a raw pipe (1) The rounding amount K in (3) was examined using a projector. The results are shown in Table 1.

  In the column of “burr / chip” in Table 1, “◎”, “◯”, “Δ”, and “x” are given in the order from the smallest amount of outward burrs and chips. In the column of “roundness”, “O”, “Δ”, and “X” are given in descending order of the rounding amount K of the rounded portion (3).

  As shown in Table 1, by setting the tip angle α of the cutting blade (15) in the range of 30-80 ° (particularly preferably 45-70 °), the generation of burrs and chips can be reliably prevented. It was confirmed that the rounding amount K of the rounded portion (3) can be reliably increased, that is, the cut portion of the raw tube (1) can be reliably rounded.

<Examples 8 to 35>
Three elementary pipes (1) obtained by drawing and having one end (2) and a mouthpiece (2a) formed thereon were prepared. This raw tube (1) has an outer diameter of 24 mm and a wall thickness of 0.7 mm. Next, the end (2) of each elementary tube (1) was excised using the tube end excision device (10) of the first embodiment. The tip angle α of the cutting blade (15) of the tube end excision device (10) used in this excision step is set in a range of 30 to 80 °. Table 2 shows the number of revolutions around the pipe of the cutting blade (15) used in the cutting step, the feed speed, and the feed amount after cutting. Then, the shape of the cut portion of the raw pipe (1) and the amount of outward burrs generated in the cut portion of the raw pipe (1) are visually evaluated, and the cut portion of the raw pipe (1) The rounding amount K of the rounded part (3) formed was examined using a projector. The results are shown in Table 2.

  In Table 2, “Number of revolutions” is the number of revolutions around the raw tube of the cutting blade (15). The “feed speed” is a feed speed of the cutting blade (15) applied to cut off the end (2) of the raw tube (1). The “feed amount” is the feed amount after excision, that is, the feed amount of the cutting blade (15) after the end (2) of the raw tube (1) is excised. In Table 2, “1”, “2”, and “3” in the “cutting section” column are the numbers of the arbitrarily assigned raw tubes.

  Further, in the column of “shape of the cutting part” in Table 2, “◯”, “Δ”, “X”, and “XX” are given in ascending order of deformation amount of the cutting part of the raw tube (1). Further, in the column of “burrs at the cutting portion”, “O”, “X”, and “XX” are given in the order of the generation amount of outward burrs. In the column of “total evaluation”, “◯”, “Δ”, and “x” are given in the order of good comprehensive evaluation. In the column of “roundness”, “O”, “Δ”, and “X” are given in descending order of the average value of the rounding amount K of the rounded portion (3).

  As shown in Table 2, in order to prevent deformation of the cut portion of the raw tube (1), it is desirable to set the feed rate in the range of 0.5 to 1.5 m / min. It could be confirmed that it is desirable to set the range of 1 m / min. Furthermore, it has been confirmed that it is desirable to set the feed amount after excision within a range of 0.5 to 2.5 mm, and particularly desirably within a range of 0.5 to 1.5 mm.

  Further, in order to prevent the occurrence of outward burrs, it is desirable to set the feed amount after excision within a range of 0.5 to 2.5 mm, particularly within a range of 0.5 to 1.5 mm. It was possible to confirm that this was desirable.

  Further, in order to increase the rounding amount K of the rounded portion (3), it is desirable to set the feed speed in the range of 0.5 to 1.5 m / minm, particularly in the range of 1 to 1.5 m / min. It was possible to confirm that setting is desirable. Furthermore, it has been confirmed that it is desirable to set the feed amount after excision to 0.5 to 2.5 mm, and particularly to the range of 1.5 to 2.5 mm.

<Example 36>
One hundred thousand elementary tubes (1) obtained by drawing and having one end (2) formed with a mouthpiece (2a) were prepared. This raw tube (1) has an outer diameter of 24 mm and a wall thickness of 0.7 mm. Next, using this base pipe (1), a pipe (5) for a photosensitive drum base was manufactured according to the pipe manufacturing method of the first embodiment. And the incidence rate of the surface (outer peripheral surface) defect of this pipe (5) was examined. In addition, the surface (outer peripheral surface) of the pipe (5) was determined to have a surface defect if it had scratches (in detail, a scratch having a length of 0.1 mm or more) due to the inclusion of burrs and chips. As a result, the incidence of pipe surface defects was about 0.15%.

<Comparative Example 1>
100,000 pieces of the same tube (1) used in Example 1 were prepared. Next, a pipe (5) for a photosensitive drum substrate was manufactured using the base pipe (1) according to a conventional pipe manufacturing method. That is, the end (2) of the raw tube (1) was cut by linearly feeding the cutting blade so as to cross the raw tube (1) using a press cutting device. Thereafter, the pipe (1) was subjected to roll correction processing to produce a photosensitive drum base pipe. And the incidence rate of surface defect was investigated about this pipe (5). As a result, the incidence of pipe surface defects was about 0.41%.

  FIG. 10 is a graph of the occurrence rate of pipe surface defects in Example 36 and the occurrence rate of pipe surface defects in Comparative Example 1. As shown in the figure, in Example 36, it was confirmed that the occurrence rate of pipe surface defects can be significantly reduced as compared with Comparative Example 1.

<Example 37>
An element tube (1) obtained by drawing and having a mouthpiece (2a) formed at one end (2) was prepared. This raw tube (1) has an outer diameter of 24 mm and a wall thickness of 0.7 mm. Next, using this base pipe (1), a pipe (5) for a photosensitive drum base was manufactured according to the pipe manufacturing method of the first embodiment. This pipe (5) is shown in FIG. The length of this pipe (5) is 6 m. In addition, the arrow Z in the figure has shown the injection | throwing-in direction to the roll straightening apparatus (20) of this pipe (5) applied at the roll straightening process. Then, the pipe (5) was cut into 15 pieces in the length direction corresponding to the photosensitive drum base. The flare of each pipe cut product thus obtained was measured. The result is shown in FIG.

<Comparative example 2>
The same tube used in Example 37 was prepared. Next, a pipe (5) for a photosensitive drum substrate was manufactured using the base pipe (1) according to a conventional pipe manufacturing method. In the same manner as in Example 37, the pipe (5) was cut into 15 pieces in the length direction corresponding to the photosensitive drum base. The flare of each pipe cut product thus obtained was measured. The result is shown in FIG.

  11B and 11C, the vertical axis represents the relative value of the fle when the flare management value is 1.

  As can be seen from the comparison between FIG. 11B and FIG. 11C, in Example 37, the flare of the pipe cut product can be made smaller than that in Comparative Example 2, and therefore the yield of the photosensitive drum can be improved. I was able to confirm.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a pipe manufacturing method and a pipe manufacturing apparatus such as a precision pipe (for example, a pipe for a photosensitive drum base, a pipe for a lens barrel of an optical instrument).

1 ... Elementary tube 2 ... End
2a ... Mouth part 3 ... Round part 5 ... Pipe
10 ... Tube end resection device
11 ... Rotating body
12 ... Tube insertion hole
13 ... Cutting blade support member
14 ... Support shaft
15 ... Cutting blade
17 Rotation drive means
20 ... Roll straightening device
21 ... Straightening roll
30 ... Pipe manufacturing equipment
40 ... Drawing device

Claims (2)

A tube end excision step of excising at least one end of both ends of the raw tube obtained by drawing;
A roll straightening process for performing roll straightening on the raw tube that has undergone the pipe end cutting process;
In the manufacturing method of the pipe containing
The outer diameter of the raw tube is set in a range of 12 to 50 mm, and the wall thickness of the raw tube is set in a range of 0.5 to 1.5 mm.
In the tube end excision step, one or a plurality of freely rotatable disc-shaped cutting blades that are arranged in a plane perpendicular to the axis of the tube and outside the end of the tube are rotated. A method of manufacturing a pipe, wherein the end of the raw pipe is cut by sending the pipe inside the pipe while being moved relative to the pipe in the circumferential direction. A tube end excision device for excising at least one end of both ends of the raw tube obtained by drawing;
A roll straightening apparatus that performs roll straightening on the raw pipe whose end has been cut by the pipe end cutting apparatus;
In a pipe manufacturing apparatus comprising:
The outer diameter of the raw tube is set in a range of 12 to 50 mm, and the wall thickness of the raw tube is set in a range of 0.5 to 1.5 mm.
The tube end excision device includes one or a plurality of rotatable disk-shaped cutting blades that are arranged in a plane perpendicular to the axis of the raw tube outside the end of the raw tube to be cut and are not driven to rotate. In addition, the pipe manufacturing apparatus is configured such that the cutting blade is sent from the outside to the inside while being moved relative to the pipe in the circumferential direction of the pipe.

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