JP2006205282A - Machining method of outer peripheral surface of cylindrical metal fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently machine an outer peripheral surface of a cylindrical metal fitting of a small article, having a large inner diameter part on one end side, having a small inner diameter part on the other end side, being thin in the thickness in the large inner diameter part and being thick in the thickness in the small inner diameter part, without replacing a chuck. <P>SOLUTION: A chuck 1 uses a device of arranging a cylindrical chuck body 2 having fitting parts 3 and 4 around which the cylindrical metal fitting 101 is fitted and a rod 30 slidably arranged on the inside. Among the body 2, openings 18 penetrating in the radial direction of a shaft G are arranged in three places in a fitting part of the small inner diameter part 105 of the cylindrical metal fitting 101, and a chuck piece 40 is displaceably arranged in the radial direction of the shaft in the respective openings 18. The cylindrical metal fitting 101 is fitted around the fitting parts 3 and 4, and the rod 30 is slid to the tip side of the body 2, and the chuck piece 40 is pushed outside by the wedge action by a tapered tip part 31 on the tip, and the cylindrical metal fitting 101 is gripped by an inner peripheral surface of the small inner diameter part 105 being thick by its pressing force. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a cylindrical accessory part (cylindrical metal fitting), which is provided with a circular large inner diameter portion on one end side of the cylindrical metal fitting itself, concentric with a portion separated from the large inner diameter portion, and a circular small metal component. The present invention relates to a method of turning an outer peripheral surface of a cylindrical metal fitting that has an inner diameter portion and that has a thin wall thickness at a large inner diameter portion and a thick wall thickness at a small inner diameter portion.

  In the manufacture of small tubular metal fittings (cylindrical parts) such as automotive engine spark plugs and oxygen sensor main metal fittings (metal fittings), for example, metal products are forged to make almost products (cylindrical parts). It is made into a shape, and after that, it completes as a cylindrical part by processing this with a cutting machine (processing machine) (patent document 1). Specifically, a metal material is subjected to cold forging (rolling) through a plurality of processes and formed into a cylindrical shape close to the product to form a semi-finished product (material for machining). The outer peripheral surface and the like of the automatic lathe are turned or finished with a screw to complete a cylindrical metal fitting.

In order to process (turn) the outer peripheral surface of the large inner diameter portion and the small inner diameter portion in such a small cylindrical metal fitting (workpiece), it is conventionally necessary to perform the chuck replacement (replacement). The inner peripheral surface of the large inner diameter portion is chucked and processed. 6 and 7 are views showing an example of the material 101 of the cylindrical metal fitting (a main metal fitting of the oxygen sensor). 6 is a longitudinal half view, and the left half of FIG. 7 is a left side view of FIG. 6, and the right half is a right side view of FIG. The cylindrical metal fitting 101 (hereinafter, also referred to as a cylindrical metal fitting including a material and a processed product) 101 has an inner peripheral surface having a large inner diameter portion 103 at a portion closer to the left end in the figure and a large inner diameter portion 103. A small inner diameter portion 105 having a relatively small diameter is provided concentrically following the right side of. However, the cylindrical metal fitting 101 of this example has a minimum inner diameter portion 107 having a relatively smaller diameter concentrically following the right of the small inner diameter portion 105. In addition, the cylindrical metal fitting 101 of the same figure is equipped with the polygonal part 110 in the bulging shape on the outer periphery of the intermediate | middle near part of the axis G direction. Here, the inner diameter of each portion is, for example, about 16.0 mm for the large inner diameter portion 103, about 11.8 mm for the small inner diameter portion 105, and about 7.4 mm for the minimum inner diameter portion 105. When turning the outer peripheral surface of each part of the cylindrical metal fitting 101 except for the polygonal part 110, the inner peripheral surface of the large inner diameter part 103 is chucked as described above. This is because, in such a small component, it is easier to grip the inner peripheral surface of the large inner diameter portion 103 and rotational blurring is small, so that accuracy in processing can be improved.
JP 2002-11543 A

  However, in the case where the cylindrical metal fitting 101 is chucked and the outer peripheral surface thereof is turned in this way, if it is removed from the chuck after machining, the thin wall portion which is the large inner diameter portion 103 is deformed and required. High dimensional accuracy may not be obtained. The inventor of the present application investigated the cause, and when the inner peripheral surface of the thin wall portion which is the large inner diameter portion 103 is chucked, the inner peripheral surface is caused by a pressing force in the radially outward direction (pushing and spreading force) accompanying the chuck. This is because the part of the chuck hitting the nail (or top) is locally expanded outward, so that the cylindrical part is elastically deformed like a polygonal cylinder. There was found. That is, the cylindrical metal fitting 101, which is a workpiece, is turned in its chucked state, and until it is removed from the chuck (front), its outer peripheral surface is a perfect circle. This is because the roundness is lost because the deformation that has occurred is restored. This problem becomes more conspicuous as the thickness of the thin portion which is the large inner diameter portion 103 becomes thinner.

  It seems that such a problem can be solved by checking the cylindrical metal fitting 101 on the inner peripheral surface of the small inner diameter portion 105 which is a thick portion. However, the chuck that grips it on the inner peripheral surface of the small inner diameter portion 105 has a small diameter, and it is not easy to be realized even from the viewpoint of the chuck structure. In addition, even if the inner peripheral surface of the small inner diameter portion 105, which is a thick wall portion, can be chucked, the cylindrical metal fitting 101 with the large inner diameter portion 103 being too thin remains in its chucked state. When the outer peripheral surface of the large inner diameter portion 103 is processed, there is another problem that the processing accuracy is lowered due to an increase in rotational vibration of the large inner diameter portion.

  The present invention is provided with a circular large inner diameter portion on one end side of the cylindrical metal fitting itself as described above, and a circular small inner diameter portion concentric with a portion separated from the large inner diameter portion. Efficient without changing the chuck when turning the outer peripheral surface of a cylindrical metal fitting with a thin wall at the large inner diameter and a thick wall at the small inner diameter with a cutting machine It is to provide a turning method that can be performed.

In order to achieve the above object, the turning method of the outer peripheral surface of the cylindrical metal fitting according to claim 1 includes a circular large inner diameter portion on one end side of the cylindrical metal fitting itself and the other end side from the large inner diameter portion. When turning a cylindrical fitting that has a concentric and circular small inner diameter portion, a thin wall thickness at the large inner diameter portion, and a thick wall thickness at the small inner diameter portion by a cutting machine ,
A fitting that is formed into a cylindrical shape on the chuck that grips the cylindrical fitting and that is fitted to the inner peripheral surfaces of the large inner diameter portion and the small inner diameter portion by externally fitting the cylindrical fitting. A cylindrical chuck body having a joint, and a rod which is slidably arranged in the direction of the rotation axis inside the cylindrical chuck body and has a tapered portion at a tip end portion; Is provided with a plurality of openings penetrating in the radial direction of the shaft at intervals around the rotation shaft at a portion of the fitting portion where the small inner diameter portion, which is a thick metal fitting, is fitted. In addition, a chuck piece is disposed in each opening so as to be displaceable in the radial direction of the rotating shaft, and the cylindrical fitting is externally fitted to the fitting portion of the cylindrical chuck body. Below, slide the rod toward the tip of the cylindrical chuck body. Then, on the outer peripheral surface of the tapered tapered tip, the chucking piece is pushed outward in the radial direction, and by the pressing force, the cylindrical metal fitting is moved into the thick inner diameter portion. It is to use a chuck that is held on the peripheral surface.

  According to a second aspect of the present invention, the fitting portion of the chuck main body holds a small gap from each inner peripheral surface of the large inner diameter portion and the small inner diameter portion when the cylindrical fitting is externally fitted. It is formed so that it may fit, The turning method of the outer peripheral surface of the cylindrical metal fitting of Claim 1 characterized by the above-mentioned.

  According to the present invention, the following effects can be obtained. In other words, in the past, when turning the outer peripheral surface of such a cylindrical metal fitting, since the chuck was carried out on the inner peripheral surface of the large inner diameter portion which is thin, as described above, the workpiece is chucked after processing. When it is removed from the machine, the deformation at the time of chucking is restored, resulting in a decrease in dimensional accuracy after processing. On the other hand, in the present invention, since the chuck has a unique chuck structure and the inner peripheral surface of the small inner diameter portion that is relatively thicker than the thickness of the large inner diameter portion is processed by chucking, the chuck itself Since the deformation of the workpiece during chucking can be reduced, the machining accuracy on the outer peripheral surface of the cylindrical metal fitting is not lowered, and the machining can be performed without changing the chuck.

  In particular, according to the second aspect of the present invention, the fitting portion of the chuck body is fitted to the inner peripheral surface of the large inner diameter portion, which is a thin wall of the cylindrical metal fitting as a workpiece, with a small gap. Therefore, even if the large inner diameter portion becomes extremely thin, it is effective in preventing the flare during rotation of the same portion and deformation during processing. That is, in processing of the outer peripheral surface of such a cylindrical metal fitting, it is difficult to cause deformation of the large inner diameter portion, and therefore there is an effect that the outer peripheral surfaces of the large inner diameter portion and the small inner diameter portion can be processed with high accuracy.

  Embodiments of the present invention will be described in detail with reference to FIGS. However, in this embodiment, the cylindrical metal fitting 101 which is a workpiece is the same as that shown in FIGS. 6 and 7, and the shape and structure thereof will be described in further detail below. That is, the cylindrical metal fitting 101 is a material for manufacturing a metal shell constituting the oxygen sensor, and has an inner peripheral surface that is cylindrical, a large inner diameter portion 103 on the one end side from the left end in the figure, and its large size. A small inner diameter portion 105 having a relatively small diameter is concentric toward the right end in the drawing (FIG. 1), which is separated from the inner diameter portion 103, and further has a relatively smaller diameter following the small inner diameter portion 105. A minimum inner diameter portion 107 is concentric. The large inner diameter portion 103 is generally thin and formed in a cylindrical shape, and its left end portion and the right small inner diameter portion 105 portions 103a and 103b are further thinned. Incidentally, the reason why such a thin wall is used is that the large inner diameter portion 103 is caulked in the direction of the axis G and inserted into the cylindrical metal fitting 101 when other parts are assembled as an oxygen sensor in the finished product of the cylindrical metal fitting 101. This is for holding the sensor element. Since the cylindrical metal fitting 101 to be processed in this embodiment has three different diameters from the left in FIG. 6, the large inner diameter portion 103, the small inner diameter portion 105, and the minimum inner diameter portion 107. The portion 105 should be called a medium inner diameter portion.

  The small inner diameter portion 105 of the cylindrical metal fitting 101 is relatively thicker than the thin wall thickness of the large inner diameter portion 103. However, of the outer peripheral surface of the small inner diameter portion 105, the portion closer to the large inner diameter portion 103 in the axis G direction is formed in a bulging shape as a polygonal portion 110 such as a hexagon when viewed from the axis G direction. Of the outer peripheral surface of the small inner diameter portion 105 of the cylindrical metal fitting 101, a screw is formed at the large inner diameter portion 105c on the right side of the polygonal portion 110 (FIG. 1). The polygonal part 110 is a part where, after being assembled as an oxygen sensor, a screw part is formed when the sensor is attached to the exhaust pipe of the engine, for example, with a screw.

  The minimum inner diameter portion 107 on the right side of the small inner diameter portion 105 (FIG. 1) is thin. Here, among the sensor elements finally set inside the cylindrical metal fitting (main metal fitting) 101, A protective cover that covers a portion protruding from the tip of the cylindrical metal fitting 101 is fitted. The inner peripheral surface of each diameter portion is formed in a cylindrical shape parallel to the axis G. However, the middle part (boundary part) of each diameter part is formed in a taper shape, and passes through the large-diameter tapered annular surface part (shelf part) 104 shown in the drawing and leftward, and the small-diameter tapered annular surface part 106 facing left. Each is concentric and circular. In this embodiment, the cylindrical metal fitting (material) 101 that is a workpiece is made of steel or stainless steel, and is formed by cold forging into a shape that is substantially close to the final product (main metal fitting). A slight machining allowance is added to the case except for the polygonal part.

  Next, the chuck 1 in each main shaft (rotary shaft) of a processing machine (for example, a multi-axis automatic lathe) for turning the cylindrical metal fitting (main metal fitting) 101 will be described with reference to FIGS. . The chuck 1 is configured as follows, with a cylindrical chuck body (body) 2 having a cylindrical shape provided concentrically with each spindle (not shown) in a multi-axis automatic lathe. The cylindrical chuck body 2 has a cylindrical shape with a closed end (right end in FIG. 1). As shown in FIGS. 1 to 3, the cylindrical metal fitting 101 is fitted on the distal end portion 2 a of the cylindrical chuck body 2, so that the large inner diameter portion 103 and the small inner diameter portion 105 of the cylindrical metal fitting 101 are fitted. The fitting part 5 which consists of the large diameter fitting part 3 and the small diameter fitting part 4 in which the outer peripheral surface was formed in a cylindrical shape with a different diameter so as to be fitted to each inner peripheral face is provided. Among these, a boss 9 is provided in a protruding manner at the center of the tip surface 7 (tip surface of the closing portion) of the small diameter fitting portion 4, and a center hole 10 for support by the center is provided at the center of the boss 9. Is provided. Between the large-diameter fitting portion 3 and the small-diameter fitting portion 4 in the axis G direction, a tip-end annular portion 14 corresponding to the large-diameter tapered annular surface portion 104 of the cylindrical metal fitting 101 is formed. . This front-facing annular portion 14 is formed with substantially the same taper as that of the large-diameter tapered annular surface portion 104 of the cylindrical fitting 101.

  Of the distal end surface 7 of the small-diameter fitting portion 4, the outer peripheral annular portion 16 corresponding to the small-diameter tapered annular surface portion 106 of the cylindrical metal fitting 101 has substantially the same taper as the taper of the small-diameter tapered annular surface portion 106. It is formed with. Such a large-diameter fitting portion 3 and a small-diameter fitting portion 4 are formed on the chuck with a small gap (for example, a diameter difference) between the inner peripheral surfaces of the large inner diameter portion 103 and the small inner diameter portion 105 of the cylindrical fitting 101. The diameter of each outer peripheral surface is set so that 0.03 mm is held and externally fitted. However, in the overall view of FIG. 1, it is shown in a close contact state without a gap. Further, the length of the fitting portion 5 in the axis G direction is such that when the tubular fitting 101 is externally fitted and pushed into the left end side of the fitting portion 5 in FIG. The annular surface portion 106 abuts on the annular portion 16 near the outer periphery of the distal end of the small-diameter fitting portion 4, and at this time, the large-diameter tapered annular surface portion 104 in the cylindrical metal fitting 101 is an annular ring facing the distal end in the fitting portion 5. It is set to hold a gap with the portion 14. That is, the positioning in the direction of the axis G in the chuck is set to be performed by the annular portion 16 near the outer periphery of the tip of the small diameter fitting portion 4 in this embodiment.

  Inside the cylindrical chuck body 2, a cylindrical hole 20 is provided that is concentric with the shaft G of the fitting portion 5. However, the tip portion 21 of the hole 20 is formed in a tapered shape (conical truncated cone) toward the closed tip surface 7 of the cylindrical chuck body 2 in this example. A round rod 30 is arranged in the hole 20 so as to be slidable in the direction of the axis G by a driving means (not shown), and a tip end portion 31 is tapered. ing. The shaft diameter of the rod 30 is slightly smaller than the inner diameter of the hole 20, and the taper of the tip 31 of the rod 30 is the same as the taper of the hole 20 of the cylindrical chuck body 2.

  Further, the peripheral wall portion of the small-diameter fitting portion 4 in the cylindrical chuck body 2 is provided with, for example, three openings 18 that penetrate in the radial direction of the shaft G at equal angular intervals around the shaft G ( (See FIG. 4). Each opening 18 has a substantially rectangular shape as shown in FIG. 3 when the cylindrical chuck body 2 is viewed from the outer peripheral surface. In each opening 18, a chucking piece (claw) 40 is arranged in a loosely fitting manner with a minute gap around it so as to be displaceable in the radial direction with respect to the axis G of the rod 30. A cylindrical pin hole 42 having a predetermined diameter is bored in the chuck piece 40 along the axis G direction (parallel to the axis G) from the front end surface side (right end surface side in FIG. 1). Then, in a state where the chuck piece 40 is fitted in the opening 18, the pin 45 driven into the annular portion 16 near the outer periphery of the small-diameter fitting portion 4 in the cylindrical chuck body 2 from the tip side along the axis G direction. The chuck hole 40 is loosely inserted into the pin hole 42 so that the chuck piece 40 is not separated or dropped from the cylindrical chuck body 2. The pin 45 has an outer diameter that is sufficiently smaller than the inner diameter of the pin hole 42 and does not reach the hole bottom end of the pin hole 42, and is fixed to the main body 2. Accordingly, the chuck piece 40 is disposed in each opening 18 so as to be displaceable in the radial direction of the axis G of the rod 30 by the gap in the fitting of the pin hole 42 of the pin 45.

  When the chuck piece 40 is arranged in this way with respect to each opening 18, a portion (outer peripheral surface portion) 46 along the outer peripheral surface side of the small diameter fitting portion 4 of the chuck piece 40 is fitted with a small diameter. A curved surface having substantially the same radius as the outer peripheral surface of the portion 4 is presented. And the site | part (inner peripheral surface site | part) 47 located in the inner peripheral surface side of the small diameter fitting part 4 is made into the plane which has the taper which substantially corresponds with the internal peripheral surface in the axis | shaft G direction. However, when the chuck top 40 is disposed with respect to each opening 18, the inner peripheral surface portion 47 located on the inner surface side of the chuck top 40 is always from the inner peripheral surface of the small diameter fitting portion 4. It is formed so as to slightly protrude toward the axis G side. On the other hand, when the chuck piece 40 is placed in a free state, that is, when the rod 30 is slid to the rear end side of the cylindrical chuck body 2, it is displaced to the inside (axial side) of the cylindrical chuck body 2. The outer peripheral surface portion 46 is set so as not to protrude from the outer peripheral surface of the small diameter fitting portion 4. On the other hand, when the rod 30 is slid to the distal end side of the cylindrical chuck body 2, the chucking piece 40 is slightly pushed outward in the radial direction by the wedge action on the outer peripheral surface of the tapered tapered distal end portion 31. The cylindrical metal fitting 101 is formed so as to be pressed and supported (supported) outwardly on the inner peripheral surface of the thick inner diameter portion 105 by the extrusion.

  The rod 30 is slid (advanced) to the distal end side by the driving means (not shown) when the cylindrical metal fitting 101 is chucked. In other cases, the rod 30 is shown by a two-dot chain line in FIG. The chuck piece 40 is slid rearward and held at a predetermined position, and the chuck piece 40 is set in a free state. Further, in this embodiment, a chamfer (round chamfer) is attached to the peripheral edge (peripheral corner) of the outer peripheral surface portion 46 in contact with the inner peripheral surface of the small inner diameter portion 105 of the cylindrical fitting in the chuck piece 40. The inner peripheral surface of the small inner diameter portion 105 of the cylindrical metal fitting 101 is not damaged during chucking. In particular, the corner of the outer peripheral surface portion 46 of the chuck piece 40 near the tip in FIG. 1 has a corner of the large-diameter tapered annular surface portion 104 when the cylindrical fitting 101 is fitted to the chuck body 2. An inclined large chamfer 48m is provided so as not to interfere with the inner peripheral edge.

  Thus, when the outer peripheral surface of the cylindrical metal fitting 101 is turned and chucked, the cylinder is placed in the fitting portion 5 including the large-diameter fitting portion 3 and the small-diameter fitting portion 4 in the chuck body 2 described above. The metal fitting 101 is externally fitted, and the inner peripheral surfaces of the large inner diameter portion 103 and the small inner diameter portion 105 of the cylindrical metal fitting 101 are fitted. This fitting may be performed by moving the cylindrical fitting 101 in the left direction in FIG. 1 along the axis G direction so that the axis G of the cylindrical fitting 101 is aligned with the axis G of the cylindrical chuck body 2. At this time, the chuck piece 40 disposed on the lower side of the chuck 1 slightly protrudes from the opening 18 below the outer peripheral surface of the fitting portion 5 due to its own weight in the free state. Since a large inclined chamfer 48m is provided at a portion near the tip of the outer peripheral surface portion 46 of the top piece 40, there is no hindrance when the tubular metal fitting 101 is externally fitted. And after fitting the cylindrical metal fitting 101 in the fitting part 5 in the chuck | zipper main body 2 in this way, the rod 30 arrange | positioned inside the cylindrical chuck | zipper main body 2 is slid to the front end side. By doing in this way, the cylindrical metal fitting 101 which is a workpiece is chucked.

  That is, when the rod 30 is slid to the tip end side, the chuck piece 40 disposed in each opening 18 is moved to the inner peripheral surface portion 47 of the chuck piece 40 by the outer peripheral surface of the tapered tapered tip portion 31 of the rod 30. It is pressed and pushed outward in the radial direction of the axis G by the wedge action. Thus, the cylindrical metal fitting 101 is held on the inner peripheral surface of the small-diameter portion 105 which is thick due to the pressing force P as shown in the enlarged view of FIG. 1 (FIG. 1 enlarged view). And FIG. 4). As described above, in this embodiment, the chuck for turning the cylindrical metal fitting 101 is performed with a chuck having a unique chuck structure, and the cylindrical metal fitting 101 is held on the inner peripheral surface of the small inner diameter portion 105 having a thick wall. . For this reason, there is no problem in the configuration (formation) of the chuck itself, and the inner peripheral surface of the small inner diameter portion 105 that is thick is chucked, and the outer peripheral surface is processed (turned). Since the deformation of the cylindrical metal fitting 101 can be prevented at the time of chucking, an effect that the processing accuracy of the cylindrical metal fitting 101 is not lowered can be obtained.

  Further, in this embodiment, the large-diameter fitting portion 3 of the chuck body 2 is fitted to the inner peripheral surface of the thin large-diameter portion 103 of the cylindrical metal fitting 101 while holding a minute gap. Even if the large inner diameter portion 103 is extremely thin, the flare during the rotation of the portion 103 and the deformation during the turning process are effectively prevented. For this reason, turning of the outer peripheral surface of the large inner diameter portion 103 can also be performed under the same chucked state, that is, without changing the chuck. It is desirable to make this gap as small as possible within a range that does not hinder smooth fitting of the workpiece (cylindrical metal fitting) to the chuck. In order to facilitate the fitting, a chamfer 14m is formed on the intersecting ridge formed by the tip of the outer peripheral surface of the large-diameter fitting portion 3 and the outer peripheral edge of the tip-oriented annular portion 14 in the cylindrical chuck body 2. It is preferable to give. However, depending on the required machining accuracy and the thickness of the large inner diameter portion 103 in the workpiece, if there is no problem such as flutter during rotation, instead of such a small gap, as shown in FIG. A smooth chuck is hindered by the gap including the gap between the thick inner diameter portion 105 of the cylindrical metal fitting 101 and the gap between the chuck body 2 and the small diameter fitting portion 4. As long as there is not, it may be a certain size. In addition, it is preferable for chamfering 16m to also give the chamfering 16m also to the crossing ridge which the front-end | tip of the outer peripheral surface of the small diameter fitting part 4 and the outer periphery of the outer peripheral ring part 16 form.

  The present invention is not limited to the embodiment described above, and can be embodied with various design changes without departing from the gist thereof. For example, the number of chuck pieces in the chuck may be four or more. In addition, the case where the cylindrical fitting that is the workpiece is a metal fitting for the oxygen sensor has been embodied, but the method of turning the outer peripheral surface of the cylindrical fitting according to the present invention is of course applicable to other workpieces. it can. That is, the cylindrical metal fitting which is a workpiece in the present invention includes a circular large inner diameter portion on one end side of the cylindrical metal fitting itself, and a concentric circular small inner diameter portion on the other end side than the large inner diameter portion. In addition, although the thickness at the large inner diameter portion is thin and the thickness at the small inner diameter portion is thick, it can be widely applied to turning of the outer peripheral surface. Therefore, the present invention can be widely applied to various small cylindrical fittings such as a metal fitting body for various sensors for engines such as automobiles and a metal fitting body for a spark plug having such a configuration. Furthermore, in the above description, the multi-axis automatic lathe is embodied as an example in the cutting machine, but it is only necessary to be able to turn the outer peripheral surface of the cylindrical metal fitting. Therefore, as a matter of course, it can be applied to a chuck in a single-axis lathe. it can.

Sectional drawing of the principal part of the state which fitted the cylindrical metal fitting to the chuck | zipper explaining embodiment of this invention, and its principal part enlarged view. Sectional drawing of the principal part of the chuck | zipper in FIG. The figure which looked at FIG. 2 from the bottom. The AA line expanded sectional view of FIG. Sectional drawing of the principal part of another example of the state which fitted the cylindrical metal fitting to the chuck | zipper. The longitudinal section half view of a cylindrical metal fitting. The left half is a left side view of FIG. 6, and the right half is a right side view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chuck of cutting machine 2 Cylindrical chuck main body 3,5 Fitting part of cylindrical chuck main body 18 Opening in fitting part 30 Rod 31 Tip of rod 40 Chuck top 101 Cylindrical metal fitting 103 Large inner diameter part of cylindrical metal fitting 105 Small inner diameter part of cylindrical fitting G-axis

Claims (2)

The cylindrical metal fitting itself is provided with a circular large inner diameter portion on one end side, a concentric circular small inner diameter portion on the other end side than the large inner diameter portion, and the wall thickness at the large inner diameter portion is thin. When turning the outer peripheral surface of the cylindrical metal fitting whose wall thickness in the small inner diameter portion is thick with a cutting machine,
A fitting that is formed into a cylindrical shape on the chuck that grips the cylindrical fitting and that is fitted to the inner peripheral surfaces of the large inner diameter portion and the small inner diameter portion by externally fitting the cylindrical fitting. A cylindrical chuck body having a joint, and a rod which is slidably arranged in the direction of the rotation axis inside the cylindrical chuck body and has a tapered portion at a tip end portion; Is provided with a plurality of openings penetrating in the radial direction of the shaft at intervals around the rotation shaft at a portion of the fitting portion where the small inner diameter portion, which is a thick metal fitting, is fitted. In addition, a chuck piece is disposed in each opening so as to be displaceable in the radial direction of the rotating shaft, and the cylindrical fitting is externally fitted to the fitting portion of the cylindrical chuck body. Below, slide the rod toward the tip of the cylindrical chuck body. Then, on the outer peripheral surface of the tapered tapered tip, the chucking piece is pushed outward in the radial direction, and by the pressing force, the cylindrical metal fitting is moved into the thick inner diameter portion. A method of turning an outer peripheral surface of a cylindrical metal fitting, characterized by using a chuck that is gripped on the peripheral surface. The fitting portion of the chuck body is formed so as to be fitted with a small gap between the inner peripheral surface of the large inner diameter portion and the small inner diameter portion when the cylindrical metal fitting is externally fitted. The turning method of the outer peripheral surface of the cylindrical metal fitting of Claim 1 characterized by the above-mentioned.

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