JP6122760B2 - Dimple molding burnishing tool, machine tool, and dimple burnishing method - Google Patents

Description

  The present invention relates to a dimple molding burnishing tool for performing dimple molding for forming grooves and dimples (dents) by pressing a ball against a workpiece, and burnishing for crushing surface irregularities to be processed by rolling a roller on the workpiece, The present invention relates to a machine tool and a dimple burnishing method.

  Conventionally, dimple forming processing (hereinafter referred to as “dimple processing”) is performed when grooves and dimples (dents) are formed in a workpiece to reduce the frictional resistance of the sliding surface. The burnishing is performed when the surface hardness and surface roughness are improved by rotating the workpiece while pressing a roller to crush the processed surface of the workpiece and plastically deform it.

As other processing methods for attaching dimples to the outer surface of the workpiece, laser processing, WPC processing (fine particle shot peening processing), rolling processing, and the like are generally used.
Conventionally, when forming dimples on the outer surface of a workpiece, there is known a dimple forming burnishing tool that is attached to a driving machine such as a lathe, a milling machine, or a drilling machine to perform burnishing (see, for example, Patent Document 1).

JP 2010-105112 A

However, the dimple processing method using the laser processing and WPC processing has a problem that the processing time is long and the apparatus is expensive.
Further, the dimple processing method by rolling processing has a problem that stable processing is difficult when processing a mass-produced product because transfer on a micro order is performed.

  In addition, when machining with a workpiece held by a chuck, it is impossible to machine the part held by the chuck, so it is necessary to re-grip the workpiece and machine both sides, resulting in poor machining efficiency. There is a point.

  Further, in the dimple forming burnishing tool for dimple forming the outer peripheral surface in the radial direction of the workpiece as described in Patent Document 1, since the roller and the ball are arranged in the axial direction, the processing end point or start point is There is a problem that a deviation occurs between the processing range by the roller and the processing range by the ball.

  In addition, when a low-rigidity workpiece is machined with a dimple-forming burnishing tool, the work surface may bend or a bulge around the dimple may need to be crushed in a separate process. In some cases, when a large deflection occurs in the workpiece, there is a problem that it cannot be processed.

  The present invention has been made in view of such a background, and a dimple forming burnishing tool, a machine tool, and a dimple burnishing processing method having a simple and inexpensive structure capable of beautifully forming dimples on the outer peripheral surface of a workpiece. It is an issue to provide.

  In order to solve the above-mentioned problems, a dimple-forming burnishing tool according to the present invention includes an inner peripheral surface taper-shaped head in which a hollow portion is formed, and an insertion in which a workpiece is inserted in the axial direction and disposed in the hollow portion. A dimple-forming burnishing tool comprising a frame having a hole, a ball rotatably supported by the frame, and a roller rotatably supported by the frame, the inner peripheral surface of the head being And at least one groove portion for projecting and retracting the ball is formed, the ball and the roller are disposed on the same circumference, the roller is disposed across the groove portion in the axial direction, and the workpiece is inserted A dimple is formed on the outer peripheral surface of the workpiece by inserting into the hole and rotating either the head, the frame, or the workpiece by a driving means. Characterized in that it.

  With the dimple forming burnishing tool having such a configuration, since the groove is formed in the head, the ball can be projected and retracted, and the dimple can be intermittently formed on the outer peripheral surface of the workpiece inserted into the insertion hole. In addition, since the rollers are arranged in a state of straddling the groove where the ball is inserted, the roller can be continuously burned, and the peripheral part of the dimple (groove) bulged by dimple processing with the ball is crushed. It can be flat. For this reason, dimple processing and burnishing can be simultaneously and cleanly performed on the surface to be processed.

  Further, the roller is rotatably supported by being inclined at a predetermined angle with respect to the axis of the frame, the outer peripheral side surface has a tapered outer surface such as a frustoconical outer peripheral surface, and at least the head and the frame One is rotatably arranged, the roller is driven to rotate by the head or the frame, and the workpiece inserted into the insertion hole is brought into contact with the tapered outer surface of the roller, thereby feeding the workpiece. It is preferable to form the dimples with balls.

  A dimple forming burnishing tool having such a configuration includes a head having an inner peripheral surface tapered with a hollow portion formed therein, a frame having an insertion hole disposed in the hollow portion and into which a workpiece is inserted in the axial direction, and an inner portion of the head. And a roller having a tapered outer surface adapted to the peripheral surface taper, so that when the frame rotates, the tapered outer surface of the roller automatically presses the outer peripheral surface of the workpiece and automatically feeds the workpiece in the direction of reducing the taper diameter. be able to. That is, the workpiece inserted into the insertion hole of the rotating frame is intermittently dimple processed with a ball and continuously burned with a roller while being automatically fed through the insertion hole. In addition, since the dimple forming burnishing tool according to the present invention does not require a chuck for holding a workpiece, the structure can be simplified and the cost can be reduced, and the processing time can be greatly shortened.

  In addition, a shank is connected to the head or the frame, and at least one of the head and the frame is rotatably arranged, and any one of the head, the frame, or the workpiece is driven to rotate. Preferably, the dimples are formed with the balls while feeding the work or the dimple forming burnishing tool so that the work inserted into the insertion hole and the dimple forming burnishing tool move relatively.

  According to such a configuration, it is possible to perform dimple molding and burnishing by attaching the shank or workpiece to a lathe or milling machine.

  The roller is rotatably supported by the frame and formed in a columnar shape. At least one of the head and the frame is rotatably arranged, and the work is inserted into the insertion hole, and It is preferable to form the dimples with the balls by moving the workpiece with an automatic feeding device while abutting against the outer peripheral side surface of the roller and rotating the workpiece.

  According to such a configuration, the workpiece feeding speed can be easily adjusted.

  Further, the insertion hole communicates with a work insertion hole capable of discharging the work from a side opposite to the side where the head is disposed after forming a dimple on the work inserted into the insertion hole. Preferably it is.

  According to this configuration, the workpiece inserted into the insertion hole on the head side is dimple-processed and then discharged from the workpiece insertion hole on the opposite side of the head, thereby continuously moving the workpiece in one axial direction. Can be processed automatically. For this reason, the dimple forming burnishing tool can process a long workpiece at one time from one end side to the other end side of the outer peripheral surface in the radial direction. Further, the dimple-forming burnishing tool eliminates holding the workpiece with a chuck or the like, and can omit the workpiece attaching / detaching operation and the workpiece feeding device.

  Moreover, it is preferable that the dimple forming burnishing tool includes burnishing amount adjusting means for adjusting the burnishing amount.

  According to such a configuration, it is possible to set and process an appropriate burnishing amount for each workpiece.

  Moreover, it is preferable that the said insertion hole or the said workpiece | work insertion hole consists of a bottomed hole in which the said workpiece | work is inserted and removed.

  According to such a configuration, the dimple-forming burnishing tool can simplify the structure of the rear peripheral portion of the insertion hole because the insertion hole is a bottomed hole. Further, the workpiece is inserted into the insertion hole, dimple processed and burnished, and then pulled back from the insertion hole, whereby the processing operation is completed.

  A machine tool according to the present invention is a machine tool provided with a dimple forming burnishing tool, and is characterized by comprising a driving means for rotating the head, the frame, or the workpiece.

  According to such a configuration, the machine tool according to the present invention includes the driving means for rotating the head, the frame, or the workpiece of the dimple forming burnishing tool. Since the balls and rollers of the forming burnishing tool or the workpiece can be rotated, the surface to be processed of the workpiece can be subjected to dimple processing and burnishing simultaneously.

  The dimple burnishing method according to the present invention includes the dimple burnishing tool or the dimple burnishing method in which the workpiece is dimple formed using the machine tool, and the ball is formed on the outer peripheral surface of the workpiece. And burnishing while forming dimples by pressing and rolling the roller.

  According to such a configuration, the dimple-forming burnishing tool or the machine tool can be used to easily dimple the radial outer circumferential surface of the workpiece having a circular cross section with a ball and burnishing with a roller. The surface hardness and surface roughness can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the dimple shaping | molding burnishing tool, machine tool, and dimple burnishing method of the cheap and simple structure which can shape | mold a dimple on the outer peripheral surface of the radial direction of a workpiece | work stably can be provided.

1 is a half sectional view showing a dimple molding burnishing device and a machine tool according to an embodiment of the present invention. It is a perspective view which shows the partial cross section which shows the dimple shaping | molding burnishing apparatus which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view taken along line XX in FIG. 1, (a) is a state before dimple processing, (b) is a state where the ball rides on the convex portion of the head, and (c) is a state where the ball is in the concave portion of the head It is a figure which shows a state when depressed. (A) is a figure which shows the measurement result of the surface of the workpiece | work before processing with a dimple shaping | molding burnishing tool, (b) is a figure which shows the measurement result of the to-be-processed surface of the workpiece | work after machining with a dimple shaping | molding burnishing tool. is there. The top view of the to-be-processed surface processed with the dimple shaping | molding burnishing tool which concerns on embodiment of this invention, (b) is the top view of the to-be-processed surface processed with the dimple shaping | molding burnishing tool provided with two balls, (c) is It is a top view of the to-be-processed surface processed with the dimple shaping | molding burnishing tool provided with one ball | bowl. It is a half sectional view showing the 1st modification of a dimple forming burnishing tool concerning an embodiment of the present invention.

  Hereinafter, a dimple forming burnishing tool 1, a machine tool, and a dimple burnishing method according to an embodiment of the present invention will be described with reference to the drawings. For convenience of explanation, in the dimple forming burnishing tool 1, the side on which the head 2 is disposed is referred to as a front side (front part), and the opposite side is referred to as a rear side (rear part). Before describing the dimple forming burnishing tool 1, a work W to be processed and a dimple forming burnishing apparatus S to which the dimple forming burnishing tool 1 is attached will be described.

≪Work structure≫
The workpiece W is composed of a rod-like member such as a shaft. The material of the workpiece W is not limited to metal, and may be wood, resin, or the like. Examples of workpieces W include camshafts, power steering shafts, brake cylinder pistons, automatic transmission shafts, air / hydraulic piston rods, piston pins, DVD drive lead screws, pump plungers, dial gauges Spindles, camera zoom shafts, printer shafts, motor shafts, fishing tackle reel shafts, and the like. In addition, it is possible to add a pattern as a decoration to a shaft of furniture or stationery. Moreover, as a material of the workpiece | work W, it can also process into a polishing material or the drawing material itself.

≪Configuration of dimple molding burnishing device≫
As shown in FIG. 1, the dimple-forming burnishing device S is a device that performs dimple processing and burnishing on a radially outer peripheral surface of a substantially cylindrical or round bar-shaped metal workpiece W extending in the axial direction. is there. That is, the dimple forming burnishing device S forms a groove or dimple Wc (dent) for reducing the frictional resistance of the sliding surface on the workpiece W, and rotates the workpiece 5 while pressing the roller 5 against the workpiece W. It has a function of plastically deforming the processed surface of W to be crushed and improving the surface hardness and surface roughness to make a mirror surface. The dimple molding burnishing device S includes a dimple molding burnishing tool 1 including a driving unit 10 that is rotationally driven by a motor 11, a ball 4 and a roller 5 that are rotationally driven using the power of the driving unit 10, and a dimple molding burnishing. The apparatus mainly includes a support member 20 that holds the tool 1, and a drive unit 10 and an apparatus main body (not shown) that holds the support member 20.
The dimple forming burnishing device S is an optimal device for dimple processing and burnishing on the outer peripheral surface in the radial direction of the workpiece W made of a rod-shaped member.

≪Configuration of drive means≫
The driving means 10 rotates the frame 3 fixed to the stem 6 disposed at the rear end portion of the dimple forming burnishing tool 1, thereby disposing the processing balls 4 disposed inside the frame 3 and contacting the workpiece W. And a rotation driving device for rotating the roller 5. The drive means 10 includes, for example, an electric motor 11, a drive pulley 12 driven by the motor 11, a belt 13 wound around the drive pulley 12, and a driven pulley that is wound around the belt 13 and rotated. 14 is mainly provided. The driving means 10 is provided in an apparatus main body (not shown).

  In addition, in the drive means 10, the structure of the power transmission means which transmits rotation of the motor 11 to the dimple shaping burnishing tool 1 is not specifically limited. The power transmission means may be a chain transmission mechanism, a gear transmission mechanism, or the like other than the belt transmission mechanism. Hereinafter, a belt transmission mechanism including a drive pulley 12, a belt 13, and a driven pulley 14 will be described as an example of the power transmission means.

  The motor 11 is electrically connected to a power source via a control device (not shown). The motor 11 includes a motor shaft 11a that rotates integrally with a rotor (not shown). The front end portion of the motor shaft 11 a is inserted into the bearing portion of the drive pulley 12. The motor 11 is mounted on the apparatus main body (not shown).

  The drive pulley 12, the belt 13, and the driven pulley 14 constitute a belt reduction mechanism that decelerates the rotation of the motor shaft 11 a rotated by the motor 11 and transmits it to the stem 6 of the dimple forming burnishing tool 1. The drive pulley 12 is a belt wheel around which a belt 13 is wound, and has an outer diameter smaller than that of the driven pulley 14.

  The belt 13 is not particularly limited as long as it is wound around the drive pulley 12 and the driven pulley 14 and can transmit power. The belt 13 is composed of, for example, a flat belt or a V belt.

  The driven pulley 14 is a belt wheel that is formed to have an outer diameter larger than that of the driving pulley 12 and decelerate the rotation of the driving pulley 12. The bearing portion 14a of the driven pulley 14 is brought into contact with a stepped surface 6b formed on the rear end side of the stem 6 and is externally fitted to the small diameter portion 6c with a key or the like (not shown) interposed therebetween, and the small diameter portion 6c. The fixing nut N1 is screwed onto the stem male screw portion 6d formed at the rear end portion, so that it is sandwiched between the step surface 6b and the fixing nut N1.

≪Configuration of dimple forming burnishing tool≫
As shown in FIG. 1, the dimple-forming burnishing tool 1 performs dimple processing to form dimples by pressing against the processing surface of the workpiece W with a ball 4, and rolls the processing surface of the workpiece W with a roller 5. A tool for performing burnishing to improve surface hardness and surface roughness. The dimple-forming burnishing tool 1 is a tool that is fixed to an apparatus main body (not shown) by holding a body 9 installed on the outer peripheral portion on a support member 20, and includes a burnishing amount adjusting means 30. .

  The dimple-forming burnishing tool 1 includes a substantially cylindrical head 2 having a tapered inner surface portion 2d (see FIG. 2), a substantially cylindrical frame 3 having an insertion hole 3a, a ball 4 supported by the frame 3, and a taper. The roller 5 having the outer surface 5a, the stem 6 connected to the rear end side of the frame 3, the housing 7 provided with the bearing B on the outer peripheral portion of the stem 6, and the outer peripheral portion of the housing 7 The thimble 8 and the body 9, the adjust string R disposed on the outer periphery of the thimble 8, the lock nut N2 for fixing the adjust string R, the fixing nut N1 for fixing the driven pulley 14 to the stem 6, and the burnishing amount And a workpiece self-propelling mechanism 40 that moves the workpiece W rearward.

<Configuration of head>
As shown in FIG. 1, the head 2 is a substantially cylindrical metal member disposed outside the front end portion of the dimple forming burnishing tool 1 and is fitted into the thimble 8 so as to be integrally movable in the axial direction. Is provided. The head 2 constitutes one part of the burnishing amount adjusting means 30 described later. As shown in FIG. 2, the head 2 includes a hollow portion 2a formed inside, an inner peripheral surface 2b of the head 2, a groove portion 2c for ball placement formed on the inner peripheral surface 2b, and an inner peripheral surface 2b. The pressing surface 2g (see FIG. 3) alternately arranged with the groove portions 2c in the circumferential direction at a position where the ball 4 abuts, and the diameter of the inner peripheral surface 2b is reduced from the front end portion toward the rear end portion side. The formed taper inner surface portion 2d, the stopper 2e with which the chamfered opening edge of the thimble 8 abuts, and the head male screw portion 2f formed on the rear end side of the outer peripheral surface of the head 2 are provided.
The head 2, the frame 3, the roller 5, and the ball 4 are preferably made of high-strength steel or cemented carbide, and may be coated on the surface for extending the life.

For example, the small diameter portion 3b of the frame 3 on which the four balls 4 and the four rollers 5 are supported is inserted into the hollow portion 2a (see FIG. 3A).
The inner peripheral surface 2b is formed with a tapered inner surface portion 2d inclined at an angle θ1 that expands toward the front end side as a whole, and the groove portion 2c and the pressing surface 2g are arranged in the circumferential direction at a position near the front end portion. It is formed alternately.
As shown in FIG. 2, the tapered inner surface portion 2 d is disposed in a state where the ball 4 and the tapered outer surface 5 a of the roller 5 are in contact with each other. The taper angle θ1 of the tapered inner surface portion 2d is equal to the feed angle θ2 of the center line O1-O1 of the roller 5 arranged in contact with the tapered inner surface portion 2d with respect to the axial line OO, and the center line O1- The inclination is small with respect to the angle θ3 of the tapered outer surface 5a with respect to O1. For this reason, the taper inner surface portion 2d moves the position of the taper pin-shaped roller 5 that is disposed to be inclined with respect to the axial direction when the head 2 moves in the axial direction (front-rear) in conjunction with the adjust ring R. The adjustment drive surface of burnishing amount adjusting means 30 which will be described later is adjusted.

  As shown in FIGS. 1 and 2, the roller 5 constitutes a workpiece self-propelling mechanism 40. The workpiece self-propelling mechanism 40 generates a self-propelling force that moves the workpiece W backward during processing by rotating the roller 5 in conjunction with the frame 3 that rotates with the stem 6 interposed by the driving means 10. Mechanism. In the workpiece self-propelling mechanism 40, the roller 5 has a center line O1-O1 inclined with respect to the workpiece W at a feed angle θ2, and the taper outer surface 5a is inclined at an angle θ3 with respect to the roller centerline O1-O1. The work W can be automatically moved rearward by being arranged with a feed angle.

  According to this configuration, when the frame 3 rotates, the taper outer surface 5a of the roller 5 presses the outer peripheral surface of the workpiece W and automatically feeds the workpiece W in the direction in which the diameter of the roller 5 is reduced. There is no need to provide a feeding mechanism in the device S. In addition, the feed speed of the workpiece | work W can be adjusted by changing the angle of feed angle (theta) 2 (refer FIG. 2). For example, when the feed angle θ2 is increased, the feed rate is increased. In this way, the feed rate can be adjusted easily and at low cost.

As shown in FIGS. 3A to 3C, the groove 2 c of the head 2 is a groove formed on the inner peripheral surface 2 b for immersing a part of the ball 4. It arrange | positions so that a part may fit.
The pressing surface 2g is a portion where the ball 4 and the roller 5 rotated together with the frame 3 come into contact with the rotation of the frame 3. When the ball 4 and the roller 5 are pressed by the pressing surface 2g, the ball 4 and the roller 5 perform dimple processing and burnishing on the processing surface Wb of the workpiece W.
As shown in FIG. 1, the stopper 2 e is a portion that matches the front opening end of the thimble 8 that is fitted on the rear end side of the outer peripheral surface of the head 2, and is tapered in accordance with the chamfering of the front opening end of the thimble 8. Is formed.
The head male screw portion 2f is screwed to the thimble female screw portion 8b, so that the head 2 is forcibly fixed to the thimble 8 and is held so as not to rotate together even if the workpiece W is not clamped. Processing is possible.

<Frame structure>
The frame 3 includes an insertion hole 3a into which the workpiece W is inserted, a small diameter portion 3b to be inserted into the hollow portion 2a, a flange-like flange portion 3c formed on the outer peripheral surface of the central portion in the axial direction, and a flange portion A metal cylinder having a frame male screw portion 3d formed on the rear side from the rear end portion of 3c, and a ball support hole 3e and a roller support hole 3f (see FIG. 2) formed in the small diameter portion 3b. It is a member and fulfills the function of supporting the balls 4 and the rollers 5. The frame 3 has a front end portion disposed in the head 2 and a rear end portion disposed in the stem 6.

  As shown in FIG. 1, the insertion hole 3 a is disposed on the same axis as the work insertion hole 6 a formed in the stem 6, and communicates in a straight line. For this reason, the workpiece | work W is movable from the front end of the insertion hole 3a to the rear end of the workpiece insertion hole 6a. That is, the insertion hole 3a discharges the workpiece W from the rear end of the workpiece insertion hole 6a opposite to the side where the head 2 is disposed after the dimple Wc is formed on the workpiece W inserted into the insertion hole 3a. Is formed in a possible state.

The small diameter part 3b is arrange | positioned through the clearance gap with respect to the internal peripheral surface 2b of the hollow part 2a. The front end of the small diameter portion 3 b is arranged in accordance with the front opening end of the hollow portion 2 a of the head 2, and the rear end extends from the head 2 to the rear side.
The flange portion 3c is interposed between the head 2 and the stem 6, and is disposed in a state where the front end surface of the stem 6 is in contact with the rear end surface of the flange portion 3c.
The outer peripheral surface of the portion where the frame male screw portion 3d is formed is formed to have a stepped diameter decreasing toward the rear end side so as to coincide with the stepped inner surface of the stem 6, and is formed on the outer peripheral surface. It is connected to the stem 6 by a flange portion 3c (inlay portion) and a frame male screw portion 3d. Therefore, the frame 3 rotates in conjunction with the stem 6.

As shown in FIG. 3A, the ball support hole 3e is a through-hole that supports the ball 4, and four holes corresponding to the number of the balls 4 are viewed in a longitudinal section on the circumference of the frame 3. Formed at intervals of 90 degrees. The ball support hole 3e is configured such that only a part of the ball 4 is dropped from the tapered inner surface portion 2d of the ball 4 and the roller 5 that rolls on the tapered inner surface portion 2d of the head 2, so that the ball 4 intermittently moves the workpiece W. The dimple Wc is formed by being pushed into the work surface Wb.
The roller support holes 3f are through holes that support the rollers 5, and four holes corresponding to the number of the rollers 5 are arranged at intervals of 90 degrees on the circumference of the frame 3 as viewed in a longitudinal section. 3e and the circumferential direction are alternately formed.

<Ball configuration>
The balls 4 are steel balls for dimple processing, and are rotatably supported by the ball support holes 3e of the frame 3 so as to be able to roll. The balls 4 and the rollers 5 are arranged on the same circumference alternately at predetermined intervals in the circumferential direction of the frame 3. The balls 4 and the rollers 5 are made of special alloy steel and are improved in hardness, toughness and hardness by heat treatment or surface treatment.

<Roller configuration>
As shown in FIG. 2, the roller 5 is a metal rolling element in the form of a taper pin for burnishing, and the roller of the frame 3 is rotatable at a predetermined angle with respect to the axial center line OO of the frame 3. It is supported by the support hole 3f. The roller 5 includes a tapered outer surface 5a having different cross-sectional areas at both end portions in the axial direction, a rear end portion 5b having a rounded corner, and a front end portion having a larger diameter than the rear end portion 5b and having a rounded corner. 5c. The roller 5 is longer than the diameter of the ball 4 in the axial direction, and is disposed in a state of straddling the groove 2c formed in an annular shape on the inner peripheral surface 2b in the axial direction. It is rotatably arranged in 3f.

  The taper outer surface 5a has a taper that has a rear end portion 5b with a small diameter, a front end portion 5c with a large diameter, and a diameter that decreases from the front end portion 5c toward the rear end portion 5b. The tapered outer surface 5 a is formed with a tapered surface that is inclined in the same direction as the tapered inner surface portion 2 d of the head 2. As described above, the roller 5 is disposed so that the center line O1-O1 is shifted by the feed angle θ2 so that the front end side of the center line O1-O1 is expanded with respect to the axis O-O of the workpiece W inserted into the frame 3. The taper outer surface 5a is arranged with an angle θ3 shifted from the center line O1-O1.

<Stem configuration>
As shown in FIG. 1, the stem 6 is a metal cylindrical member having a workpiece insertion hole 6a through which the workpiece W after processing is discharged. The stem 6 is connected to the rear end side of the frame 3 and is rotationally driven by the driving means 10. The stem 6 includes a workpiece insertion hole 6a that is continuous with the insertion hole 3a, a step surface 6b that is disposed in a state where the front end surface of the driven pulley 14 abuts, and a small diameter portion into which the bearing portion 14a of the driven pulley 14 is inserted. 6c, a stem male screw portion 6d formed at the rear end portion of the small diameter portion 6c, and a stem female screw portion 6e screwed into the frame male screw portion 3d.

The workpiece insertion hole 6a is a hole that forms a discharge port through which the processed workpiece W is discharged, and also functions to guide the movement of the workpiece W by extending in the axial direction.
The step surface 6b, the small diameter portion 6c, and the stem male screw portion 6d are portions for holding the bearing portion 14a of the driven pulley 14, and are externally fitted to the small diameter portion 6c by a key (not shown) or an interference fit. 14a is sandwiched between the stepped surface 6b and the fixing nut N1 by screwing the fixing nut N1 onto the stem male screw portion 6d. For this reason, the stem 6 rotates integrally with the driven pulley 14.
The fixing nut N <b> 1 is a ring-shaped nut for fixing the driven pulley 14 to the stem 6.

  The housing 7 is a cylindrical metal member provided on the outer periphery of the stem 6 with a bearing B interposed therebetween and having a flange 7a at the rear end. The outer periphery of the housing 7 is fixed to the support member 20 with the body 9 interposed therebetween, and the inner periphery supports the stem 6 rotatably through the bearings B installed at the front end portion and the rear end portion. Yes.

<Configuration of burnishing amount adjusting means>
As shown in FIG. 1, the burnishing amount adjusting means 30 is based on the difference between the outer diameter before the workpiece W made of a cylindrical material is processed and the inner diameter R1 between the rollers 5 (see FIG. 3A). It is an adjustment mechanism for adjusting a so-called burnishing amount (also referred to as “burnishing amount”). The burnishing amount adjusting means 30 rotates the adjuster string R to move the head 2 screwed to the thimble 8 in the front-rear direction, thereby moving the tapered roller 5 in contact with the head 2 in the radial direction. The position of the roller 5 in the radial direction with respect to the insertion hole 3a is adjusted by fine movement.
The burnishing amount adjusting means 30 includes a thimble 8 disposed in the housing 7 so as to be able to advance and retract, an adjust string R for moving the thimble 8 in the axial direction, a body 9 screwed into the thimble male screw portion 8a of the thimble 8, and an adjuster. A lock nut N2 that restricts the rotation of the ring R and a head 2 having an inner peripheral surface 2b that is screwed into the thimble female thread portion 8b of the thimble 8 and abuts against the roller 5 are configured.

<Structure of thimble>
The thimble 8 is a substantially cylindrical metal member provided in the outer periphery of the housing 7 and the head 2 and provided in the body 9. The thimble 8 has a thimble male screw portion 8a from the front end to the rear end of the outer peripheral surface, and has a thimble female screw portion 8b on the front end side outer peripheral surface.
The rear end of the thimble male thread 8a is screwed to the body female thread 9b of the body 9, the adjuster string R is rotatably screwed to the substantially central portion, and the lock nut N2 is screwed to the front end. Yes.
A head male screw portion 2 f of the head 2 is screwed to the thimble female screw portion 8 b, and the head 2 is fixed to the front end portion of the thimble 8.

  As shown in FIG. 1, the body 9 is a member that is provided on the outer periphery of the thimble 8 and the housing 7 and is held by the support body 20 on the apparatus main body (not shown). The body 9 is a metal cylindrical member having an annular flange portion 9c at a substantially central portion. The body 9 has a cylindrical portion 9a in which the housing 7 is fitted and a support member 20 is fitted, a body female screw portion 9b screwed to the thimble male screw portion 8a of the thimble 8, and a front end surface of the support member 20 And a flange portion 9c arranged in a contact state.

The cylindrical portion 9a is sandwiched between the flange portion 7a and the adjuster ring R.
The body female thread 9b adjusts the position of the thimble 8, the head 2, and the roller 5 in the radial direction by adjusting the threaded position of the thimble male thread 8a threaded to the body female thread 9b in the front-rear direction. It can be adjusted.
A support member 20 is fixed to the outer peripheral surface of the flange portion 9c or the cylindrical portion 9a by fixing means (not shown) such as a bolt and nut.

<Adjustable configuration>
As shown in FIG. 1, the adjust ring R is an adjustment ring for adjusting the radial position (burnout amount) of the roller 5 through the thimble 8 and the head 2 by a rotating operation. The adjust ring R is a cylinder having an adjustment female thread portion Ra formed on the inner peripheral surface, a rotation operation portion Rb on the outer peripheral surface, and a plurality of locking holes Rc formed at the rear end of the rotation operation portion Rb. It consists of a shaped member. In the adjust ring R, the adjusting female screw portion Ra is engaged with the thimble male screw portion 8a and the guide groove 8c on the outer peripheral portion of the thimble 8, and the engaging claw of a turning tool (not shown) is turned into the locking hole Rc of the rotation operation portion Rb. Are engaged and rotated to move forward and backward. The adjust ring R is interposed between the body 9 and the lock nut N2 on the outer peripheral surface of the thimble 8.
The lock nut N2 is a ring-shaped loosening prevention (for prevention of falling off) nut for restricting and fixing the rotation of the adjust ring R, and is screwed into the thimble male screw portion 8a.

≪Device configuration≫
The apparatus main body (not shown) is a member constituting the main body of the dimple molding burnishing apparatus S, and the configuration, shape, and the like are not particularly limited. The apparatus main body holds the driving means 10 and the support member 20 described above.
The support member 20 is made of a thick plate-like member having a holding hole 20a in which the body 9 of the dimple forming burnishing tool 1 is mounted.

[Action]
Next, the dimple forming burnishing tool 1, the machine tool, and the dimple burnishing method according to the present embodiment will be described in the order of work steps with reference to FIGS.

  First, the lock nut N2 shown in FIG. 1 is loosened to bring the adjuster string R into a rotatable state. Next, the adjust string R is rotated left or right to move the thimble 8 and the head 2 forward and backward, thereby adjusting the burnishing amount (tool inner diameter). After adjusting the burnishing amount, whether the burnishing amount has a desired length is measured and confirmed. If the burnishing amount is appropriately adjusted, the lock nut N2 is rotated in the original direction to lock the adjuster string R, and the state is fixed.

Next, the dimple process and the burnishing process will be described.
First, the driving means 10 is driven. The rotation of the motor 11 as the driving means 10 rotates the frame 3 through the driving pulley 12, the belt 13, the driven pulley 14 and the stem 6. Next, the workpiece W is inserted into the insertion hole 3 a of the head 2. Then, the workpiece W is moved from the insertion hole 3a (front side) to the workpiece insertion hole 6a (rear side) by the workpiece self-propulsion mechanism 40, and dimple processing and burnishing processing are performed by the balls 4 and the rollers 5.
Here, the principle of dimple processing and burnishing will be described. As shown in FIG. 3A, when the ball 4 falls into the groove 2c of the head 2 and moves in the outer peripheral direction (arrow b direction), the ball 4 is not in contact with the workpiece W. Only the roller 5 is in contact with the workpiece W to perform burnishing. That is, the roller 5 rotates following the rotation of the frame 3, but does not move in the radial direction of the frame 3 and is always in contact with the outer peripheral surface of the workpiece W. For this reason, the roller 5 can stably perform the burnishing of the work surface Wb of the workpiece W.

  FIG. 3B shows a state in which the frame 3 is rotated clockwise (in the direction of arrow a) when viewed from the front side, and the ball 4 is in the state shown in FIG. 3A (the state where the ball 4 is dropped into the groove 2c). The state is shown in which the groove 2c of the head 2 is removed (moved in the inner diameter direction of the frame 3 (arrow c direction)) and the work surface Wb of the workpiece W is pushed in. At this time, the ball 4 and the roller 5 rotate (rotate) counterclockwise along the inner peripheral surface 2 b of the head 2. When the ball 4 and the roller 5 rotate counterclockwise, the workpiece W moves backward while revolving clockwise (in the direction of arrow a) along the tapered inner surface portion 2d of the head 2. At this time, the roller 5 is in contact with the workpiece W to perform burnishing.

  As shown in FIG. 3 (c), when the frame 3 further rotates, the ball 4 falls again into the groove 2c and comes into a non-contact state with the workpiece W, and each ball 4 has one dimple Wc (groove). Form. Thus, when each ball 4 rotates together with the frame 3 and alternately contacts the groove 2c and the pressing surface 2g of the head 2, when the ball 4 contacts the pressing surface 2g, the ball 4 is pivoted by the pressing surface 2g. The dimple Wc is intermittently formed by pressing the work surface Wb of the workpiece W by pressing in the center direction. The roller 5 performs burnishing by continuously pressing the work surface Wb other than the dimples Wc of the workpiece W.

When the frame 3 continues to rotate, the above-described processing steps (FIGS. 3A to 3C) are repeated, and the four balls 4 intermittently form dimples Wc (grooves).
On the other hand, the roller 5 passes over the dimple Wc (groove) processed intermittently with the ball 4 while revolving, but contacts the outer peripheral surface of the workpiece W across the groove portion 2c into which the ball 4 is dropped. Therefore, the outer peripheral surface of the workpiece W is burnished continuously, and the convex portions at the peripheral edge of the dimple Wc generated by the dimple processing are crushed by the roller 5 to finish the surface smooth. As a result, regular and beautiful dimple formation and mirror finish are performed on the outer peripheral surface of the workpiece W.
In this embodiment, the dimple Wc shown in FIG. 5A is formed on the workpiece surface.

  Further, the dimple-forming burnishing device S presses the work surface Wb of the workpiece W with the plurality of balls 4 and the plurality of rollers 5, so that the pressing force that presses the workpiece W is evenly distributed and does not bend. Therefore, even the workpiece W made of a material having low rigidity can be dimple processed.

FIG. 4A is a view showing a measurement result of the surface of the workpiece W before being processed by the dimple forming burnishing tool 1, and FIG. 4B is a view of the workpiece W after being processed by the dimple forming burnishing tool 1. It is a figure which shows the measurement result of the process surface Wb.
As shown to Fig.4 (a), the surface roughness of the surface of the workpiece | work W before a process is a rough state. When this workpiece W is machined with the dimple molding burnishing tool 1, the surface Wb of the workpiece W is improved in surface roughness (Wd) as shown in FIG. It can be seen that the grooves are formed.

  When dimple processing and burnishing are completed, the workpiece W is removed from the dimple forming burnishing tool 1. Removal of the workpiece W, as described above, if the roller 5 continues to rotate through the frame 3 or the like by the driving means 10, the workpiece W moves rearward due to the rotation of the roller 5, and thus the workpiece insertion hole 6 a of the stem 6. It is only necessary to receive the workpiece W that is automatically discharged from the machine. Thus, the dimple processing by the ball 4 and the burnishing processing by the roller 5 are completed at the same time.

As described above, the dimple forming burnishing apparatus S has a centerless structure in which the dimple forming burnishing tool 1 has the insertion hole 3a and the work insertion hole 6a, so that the work W can be held in one pass without holding the work W with a chuck or the like. It is automatically fed so that the entire circumferential surface can be machined. This eliminates the need for a chuck or workpiece W feeding device, thus simplifying the structure and reducing costs.
In addition, when the workpiece W is processed, it is not necessary to clamp the workpiece W, and the workpiece W is processed while being linearly moved. Therefore, if the workpiece W has a linear shape that can be inserted into the insertion hole 3a and the workpiece insertion hole 6a, There is no limit on the processing length. As a result, even the elongated rod-shaped workpiece W can be dimple processed.

[First Modification]
The present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the technical idea. The present invention extends to these modifications and changes. Of course.
FIG. 6 is a half sectional view showing a first modification of the dimple forming burnishing tool according to the embodiment of the present invention.

  The dimple forming burnishing tool 1 of the dimple forming burnishing apparatus S (see FIG. 1) described in the above embodiment is a driving means for a machine tool such as a lathe (not shown) or a machining center, like the dimple forming burnishing tool 1A shown in FIG. The shank 6A may be connected to (not shown), the frame 3A or the head 2A may be rotated by a motor (not shown), and the outer peripheral surface of the workpiece W may be dimple processed and burnished.

  In this case, the dimple-forming burnishing tool 1A includes, for example, a shank 6A that is mounted on a machine tool (not shown) and rotates, a frame 3A that rotatably supports the ball 4A and the roller 5A, and a shank 6A and a thimble. A head 2A connected to the ball 4A and the roller 5A on the outer peripheral side of the ball 4A and the roller 5A, a spring SP for urging the head 2A forward, and the head 2A and the shank 6A. The thimble 8A fitted on the outer periphery, the adjuster RA that can move the head 2A in the front-rear direction, the burnishing amount adjusting means 30A that adjusts the burnishing amount, and the workpiece self-propulsion that moves the workpiece W backward. The mechanism 40A is mainly provided.

  The shank 6A is a mounting portion with a drive machine, the rear end portion is mounted on a machine tool or the like (not shown), rotates, and is formed in a cylindrical shape having a workpiece insertion hole 6a along the axis. The side has a shank male screw portion 6Ad on the outer peripheral surface formed in a cylindrical shape having a larger diameter on the rear end side.

  The frame 3A is a cylindrical member having a ball support hole 3Ae into which the ball 4A is inserted and a roller support hole 3Af into which the roller 5A is inserted. The frame 3A is provided so as to rotate following the rotation of the shank 6A and the head 2A when the workpiece W is inserted into the insertion hole 3Aa. Hereinafter, the case where the head 2A is connected to the shank 6A and rotates integrally will be described.

The head 2A is formed of a substantially cylindrical member having a groove portion 2Ac into which the ball 4A is dropped on the inner peripheral surface 2Ab and a tapered inner surface portion 2Ad, as in the above embodiment.
The ball 4A is a steel ball for dimple processing.
The roller 5A is a taper pin for burnishing as in the above embodiment, and constitutes a workpiece self-propelling mechanism 40A that moves the workpiece W backward. A center line (not shown) of the roller 5A is disposed so as to be inclined with respect to the axial center OO of the frame 3A and the shank 6A. The dimple-forming burnishing tool 1A is used by being mounted on a lathe, a milling machine or the like. Since the lathe or the like is provided with a feed mechanism, the roller 5A is not necessarily inclined with respect to the axis OO, There is no need to provide the self-propelling mechanism 40A.

The thimble 8A is screwed to the outer peripheral surface of the shank 6A so as to be movable in the front-rear direction, and is fitted on the outer peripheral portion of the head 2 so as to move in the front-rear direction integrally with the head 2.
The adjust ring RA has an adjustment female screw portion RAa that is screwed into the shank male screw portion 6Ad formed on the outer peripheral surface of the shank 6A. By rotating the adjust string RA, the head 2A is interposed via the thimble 8A. It can be moved back and forth.

  The burnishing amount adjusting means 30A has a head 2A having an adjusting adjust ring RA and a taper inner surface portion 2Ad that moves integrally in the front-rear direction by the adjust string RA and abuts the outer peripheral surface of the ball 4A. And a roller 5A and a ball 4A for adjusting the burnishing amount.

The dimple forming burnishing apparatus SA of the first modified example configured as described above is similar to the above embodiment by mounting the dimple forming burnishing tool 1A on a machine tool such as a lathe and using the driving force of the machine tool. The workpiece W can be burned simultaneously with dimple processing.
Further, the adjust ring RA is rotated to move the head 2A in the front-rear direction via the thimble 8A, thereby adjusting the position of the roller 5A and the ball 4A in the radial direction from the axial center and adjusting the burn amount. Fine adjustments can be made.

[Second Modification]
In the first modification, the head 2A is rotated by the machine tool with the shank 6A interposed therebetween, but the head 2A may be directly rotated (second modification).
In the case of this second modification, the dimple-forming burnishing device directly drives the head 2A to rotate with a machine tool, or provides a driven pulley or the like on the outer peripheral surface of the head 2A to drive means 10 (see FIG. 1) and The head 2A is rotated by the belt 13 via the driven pulley. Thus, even if the head 2A is rotationally driven, the outer peripheral surface of the workpiece W can be dimpled and burnished.

[Third Modification]
In the first modification, the head 2A is rotated by the machine tool with the shank 6A interposed therebetween, but the frame 3A may be driven to rotate (third modification). Further, in the dimple molding burnishing apparatus S shown in FIG. 1, the frame 3 is rotated by the driving means 10, but it is sufficient that at least one of the head 2 and the frame 3 is rotated.
In the case of this third modified example, the dimple molding burnishing device connects the frame 3A to the shank 6A, fixes the head 2A, and rotationally drives the frame 3A with the shank 6A by a machine tool. Similarly, even if the frame 3A is rotated and the head 2A is fixed, the outer peripheral surface of the workpiece W can be dimple processed and burnished.

[Fourth Modification]
In the modified example, the shank 6A and the head 2A of the dimple forming burnishing tool 1A are rotated by the driving machine. However, the work W is rotated by the driving machine and inserted into the dimple forming burnishing tool 1A, and the work W or the dimple forming burnishing is obtained. Either one or both of the tools 1A may be processed while being fed by an automatic feeding device that relatively moves the workpiece W and the dimple forming burnishing tool 1A (fourth modification).
In the case of the fourth modified example, the roller 5 in contact with the workpiece W is driven to rotate and the head 2 or the frame 3 is in a fixed state, and the rotating workpiece W rolls while rotating the roller 5 and ball The dimples Wc are formed in pressure contact with 4.

[Fifth Modification]
In the dimple molding burnishing device S of the above embodiment, the case where the frame 3 is rotated by the motor 11 is described as an example, but at least one of the frame 3 and the head 2 is provided to rotate. There should be (5th modification). In this case, at least one groove 2c is formed at a location where the inner peripheral surface 2b of the head 2 and the ball 4 are in contact with each other.
For example, even if the head 2 is rotated by the motor 11 and the frame 3 is fixed, the roller 5 in contact with the head 2 is rotationally driven to bring the workpiece W into contact with the outer peripheral surface of the roller 5. The dimple Wc can be formed with the ball 4 while feeding the workpiece W.

  As described above, the dimple forming burnishing tool 1, 1 </ b> A according to the present invention rotates either the head 2, 2 </ b> A, the frame 3, 3 </ b> A, or the workpiece W by the driving means 10 (or the driving means of the machine tool). The outer peripheral surface of the workpiece W with the balls 4 and 4A while feeding the workpiece W or the dimple forming burnishing tool 1, 1A so that the workpiece W inserted into the insertion holes 3Aa, 3a and the dimple forming burnishing tool 1, 1A move relatively. Dimples can be formed on

[Sixth Modification]
In the above embodiment, the case where the four balls 4 and the four rollers 5 are alternately arranged at equal intervals as an example of the dimple-forming burnishing tool 1 has been described, but the present invention is limited to this. It is not a thing. The dimple-forming burnishing tool 1 has a dimple shape and a dimple by appropriately changing the number of balls 4 and rollers 5, the outer diameter of the balls 4, the outer diameter and shape of the rollers 5, the roller feed angle, the concave shape of the head 2, and the like. The distribution may be changed by manipulating (sixth modification).

For example, when the number of balls 4 of the dimple forming burnishing tool 1 is two in total, the dimple Wc1 and the burnishing Wd1 can be formed on the work W1, as shown in FIG. The dimples Wc1 are processed so that the distance between the dimples Wc1 is widened by reducing the number of balls 4 by half.
Further, when the number of balls 4 of the dimple forming burnishing tool 1 is one in total, the dimple Wc2 and the burnishing Wd2 can be formed on the work W2, as shown in FIG. In this case, the dimples Wc1 are processed so that the distance between the dimples Wc2 is further increased as the number of the balls 4 is further reduced.

[Other variations]
The dimple-forming burnishing tool 1A in the first modified example has a workpiece insertion hole 6Aa, and the workpiece W is discharged from a discharge port on the rear side of the workpiece insertion hole 6Aa opposite to the insertion hole 3Aa, but the workpiece insertion hole 6Aa. Even if the dimple-forming burnishing tool 1A is closed, the workpiece W can be dimpled and burnished. That is, the insertion hole 3Aa or the workpiece insertion hole 6Aa may be a bottomed hole into which the workpiece W is inserted and removed. In this case, when the work W reaches the closed portion and the processing is finished, the motor 11 may be stopped and the work W may be pulled out manually.

  Moreover, although the case where the electric motor 11 was utilized as the drive means 10 which rotates the stem 6, the flame | frame 3, etc. of the dimple shaping burnishing tool 1 was demonstrated, what is necessary is just what can rotate them, for example, An air motor that uses compressed air, a hydraulic motor that uses hydraulic pressure, a motor that uses a motor, or the like may be used.

  Moreover, durability etc. can be improved by carrying out surface treatment of the consumable parts, such as the ball | bowl 4 and the roller 5 of the dimple shaping | molding burnishing apparatus S suitably.

S, SA Dimple forming burnishing device 1, 1A Dimple forming burnishing tool 2, 2A Head 2a Hollow portion 2b, 2Ab Inner peripheral surface 2c, 2Ac Groove portion 2d, 2Ad Taper inner surface portion (inner peripheral surface taper)
3, 3A frame 3a insertion hole 4, 4A ball 5, 5A roller 5a taper outer surface 6a, 6Aa work insertion hole 6A shank 11 driving means 30 burnishing amount adjusting mechanism (burnishing amount adjusting means)
W, W1 Work Wc, W1c Dimple

Claims (9)

A head having a tapered inner peripheral surface with a hollow portion formed therein;
A frame having an insertion hole into which the workpiece is inserted in the axial direction and disposed in the hollow portion;
A ball rotatably supported by the frame;
A dimple-forming burnishing tool comprising a roller rotatably supported by the frame,
On the inner peripheral surface of the head, at least one groove for allowing the ball to appear and disappear is formed,
The ball and the roller are arranged on the same circumference,
The roller is disposed across the groove in the axial direction,
A dimple is formed on the outer peripheral surface of the workpiece by inserting the workpiece into the insertion hole and rotating any of the head, the frame, or the workpiece by a driving means. Molding burnishing tool. The roller is rotatably supported by being inclined at a predetermined angle with respect to the axis of the frame, and the outer peripheral side surface has a tapered outer surface such as a frustoconical outer peripheral surface,
At least one of the head and the frame is rotatably arranged,
The roller is driven to rotate by the head or the frame, and the work inserted into the insertion hole is brought into contact with the taper outer surface of the roller to form the dimple with the ball while feeding the work. The dimple forming burnishing tool according to claim 1. A shank is connected to the head or the frame,
At least one of the head and the frame is rotatably arranged,
Any one of the head, the frame or the workpiece is driven to rotate, and the workpiece or the dimple-forming burnishing tool is moved relative to the workpiece inserted into the insertion hole and the dimple-forming burnishing tool. The dimple forming burnishing tool according to any one of claims 1 and 2, wherein the dimple is formed with the ball while feeding a wire. The roller is rotatably supported by the frame and formed in a cylindrical shape,
At least one of the head and the frame is rotatably arranged,
The workpiece is inserted into the insertion hole, and the dimple is formed by the ball by moving the workpiece with an automatic feeding device while being brought into contact with the outer peripheral side surface of the roller and rotating the workpiece. The dimple forming burnishing tool according to claim 1.   The insertion hole communicates with a work insertion hole capable of discharging the work from the side opposite to the side where the head is disposed after forming dimples on the work inserted into the insertion hole. The dimple-forming burnishing tool according to any one of claims 1 to 4, wherein:   The dimple-forming burnishing tool according to any one of claims 1 to 5, further comprising burnishing amount adjusting means for adjusting the burnishing amount.   The dimple forming burnishing tool according to any one of claims 1 to 6, wherein the insertion hole or the workpiece insertion hole is a bottomed hole into which the workpiece is inserted and removed. A machine tool comprising the dimple-forming burnishing tool according to any one of claims 1 to 7,
A machine tool comprising drive means for rotating the head, the frame, or the workpiece. In the dimple burnishing method according to any one of claims 1 to 8, or the dimple burnishing method in which the workpiece is dimple formed using the machine tool according to claim 8.
A dimple burnishing method characterized by burnishing while forming dimples by pressing and rolling the ball and the roller against the outer peripheral surface of the workpiece.

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