JP2008246590A - Planar burnishing tool and burnishing method - Google Patents

Abstract

An object of the present invention is to provide a burnishing tool for a plane and a burnishing method capable of burnishing a bottom surface of a narrow flat end groove and a small-diameter circular end surface.
A planar burnishing tool (1) includes a cylindrical shank (3) mounted on a processing machine, a mandrel (2) that is inserted into and supported by the shank (3), and rotates integrally with the shank (3). An urging means SP for urging the mandrel 2 in the direction of the arranged work, and an urging force adjusting means 5 for adjusting the urging force generated by the urging means SP, are provided on the plane of the work with the tip 2f of the mandrel 2 To process. The tip portion 2 f of the mandrel 2 is installed eccentrically with respect to the rotation center Oa of the planar burnishing tool 1.
[Selection] Figure 1

Description

  The present invention relates to a burnishing tool for a plane and a burnishing method for performing burnishing by pressing against a plane portion of the surface of a workpiece.

  Conventionally, as a means of finishing the surface of a workpiece made of a metal material, a smooth finished surface such as a mirror surface can be obtained by rolling and pressing a roller onto minute irregularities on the surface of the workpiece for plastic deformation. There is a rolling process (burnishing process). In this burnishing process, various types of burnishing tools are mounted on a machine tool such as a lathe, and the parts of all shapes such as the inner diameter surface, outer diameter surface, end surface, taper surface, R surface, and spherical surface of the workpiece are rolled. Thus, the surface roughness and strength can be improved.

  FIG. 9 is a view showing a conventional burnishing tool for flat mirror finish, in which (a) is a side view, (b) is a front view, and (c) is a side view showing a state during machining of a workpiece having a stepped surface. FIG. 4D is an enlarged side view of a main part showing a state of a work on a small-diameter end face subjected to burnishing. FIG. 10 is a view showing a conventional burnishing tool for finishing a circular flat end mirror surface, wherein (a) is a side view having a partial cross section, and (b) is a workpiece processed with a burnishing tool for circular flat end mirror finishing. It is a principal part enlarged plan view which shows a processing surface.

  Conventionally, as a tool for performing burnishing by pressing a roller against a flat portion of the surface of a workpiece, a burnishing tool 100 for finishing a plane mirror as shown in FIG. 9 and a circular flat end mirror as shown in FIG. A finishing burnishing tool (see, for example, Patent Document 1) 200 is used.

  As shown in FIGS. 9 (a), (b), (c), (d) and FIGS. 10 (a), (b), any of the burnishing tools 100, 200 has a rotational motion or straight motion ( The disk-shaped frames 120 and 220 are connected to the shanks 110 and 210 fixed to the main shaft of the drive mechanism capable of feeding), and the rollers 130 and 230 are placed in the grooves formed radially on the front end surfaces of the frames 120 and 220. It is mainly composed of pivots.

  The rollers 130 and 230 are pressed by the mandrels 140 and 240 toward the plane portion of the surface of the workpiece. When the shanks 110 and 210 are rotated while the rollers 130 and 230 are pressed against the surface of the workpiece, As the rollers 130 and 230 rotate (rotate), they circularly move (revolve) with respect to the centers of the frames 120 and 220. As a result, the surface of the workpiece is rolled along the locus of circular motion of the rollers 130 and 230 and burnished.

The planar mirror finish burnishing tool 100 shown in FIG. 9C is attached to a driving unit (not shown) such as a machining center and rotated to rotate the burnishing tool 100 with a roller 130 to be machined surface W1a. , The workpiece W1 is sent in the lateral direction, and a flat desired surface W1a is burnished.
As shown in FIG. 9A, for example, a plurality of rollers 130 are arranged radially from a position away from the center O1 of the frame 120 in the outer circumferential direction by a radius C1 (for example, 4 mm) to an outer diameter B1 (for example, 28 mm). The effective machining diameter A1 is 20 mm. For this reason, the burnishing tool 100 having the roller 130 is suitable for machining a wide range.

As shown in FIG. 10A, the roller 230 is, for example, radially from a position away from the center O2 of the frame 220 in the outer peripheral direction by a radius C2 (for example, 0.75 mm) to an outer diameter B2 (for example, 10.5 mm). Is arranged in multiple. For this reason, the burnishing tool 200 having the roller 230 is suitable for processing the bottom surface of a wide groove or the like.
In the burnishing tool 200 for finishing the circular flat end mirror surface, the work W3 is rotated and used, or the burnishing tool 200 is rotated and burnishing is performed. Therefore, the work surface W3a is shown in FIG. It has a ring shape like this.

  In addition, a burnishing tool having a cone-shaped burnishing part as disclosed in Patent Document 2 is known as a tool capable of burnishing the stepped surface W1b.

JP 2002-127002 A JP 2001-260017 A

  However, since the burnishing tool 100 for flat mirror finish as shown in FIGS. 9A to 9B does not include a spring for adjusting the processing pressure, the burnishing tool 100 cannot cope with variations in the dimensions of the workpiece W1 and is fixed. There was a problem that it was difficult to generate thrust (working pressure).

  The burnishing tool 100 is, for example, for burnishing a wide flat work surface W1a as shown in FIG. 9C. Therefore, when the work surface W1a has a narrow step surface W1b, There was a problem that the inside of the stepped surface W1b could not be burned.

  The burnishing tools 100 and 200 as shown in FIG. 9A and FIG. 10A have rollers 130 and 230, so that the outer diameters B1 and B2 that are the processing ranges are increased. There is a problem that the bottom surface of the steel cannot be burnished.

  The burnishing tool disclosed in Patent Document 2 is a dedicated tool for burnishing the tapered inner surface W1c formed in the step surface W1b, and the bottom surface in the step surface W1b cannot be burned. There was a point.

  The above-described burnishing tool 100 for finishing a flat mirror as shown in FIGS. 9A and 9B has a workpiece W2 when the work surface W2a of the workpiece W2 as shown in FIG. 9D is a circular flat end surface. When the roller 130 comes into contact with the outer peripheral end of the processed surface W2a, the outer peripheral end is processed to be rounded and chamfered, so that a so-called sagging is formed. It was. For this reason, the burnishing tool 100 provided with the roller 130 has a problem that it is unsuitable for the burnishing of the small-diameter end face.

  On the other hand, when the workpiece W3 is burnished with a plane mirror finish burnishing tool as shown in FIGS. 10 (a) and 10 (b), the roller 230 is removed from the center O2 of the frame 220 at a radius C2 in the outer circumferential direction. Since they are arranged in the radial direction, there is a problem that an unprocessed portion W3b having a diameter of about 1.5 mm is formed on the center O2 side.

  Therefore, the present invention has been made to solve such problems, and provides a burnishing tool for a plane and a burnishing method capable of burnishing a narrow flat end groove bottom surface and a small diameter circular end surface. Is an issue.

  In order to solve the above-mentioned problems, the invention of the planar burnishing tool according to claim 1 includes a cylindrical shank mounted on a processing machine, a mandrel that is inserted into and supported by the shank and rotates integrally with the shank. And a biasing means for biasing the mandrel in the direction of the workpiece disposed on the tip end side of the shank, and a biasing force adjusting means for adjusting a biasing force generated by the biasing means. Further, it is a planar burnishing tool that presses and processes the tip portion of the mandrel, and the tip portion is installed eccentrically with respect to the rotation center of the planar burnishing tool.

According to the invention of the planar burnishing tool according to claim 1, the tip of the mandrel is installed eccentrically with respect to the rotation center of the planar burnishing tool, so that the planar burnishing tool rotates and burnishing is performed. When machining, machining is performed to draw a locus circle whose radius is the length from the center of rotation to the maximum outer diameter part of the planar burnishing tool, eliminating the occurrence of unmachined parts in the machined circle. In addition, it is possible to process a narrow portion.
Here, “narrow” means the minimum width that can be processed with a roller-type planar burnishing tool that is processed by a roller, and the planar burnishing tool of the present invention has a narrower portion. Can be processed.

  The planar burnishing tool according to claim 2 is the planar burnishing tool according to claim 1, wherein the eccentric center of the tip is a length of a radius of the tip from a center line of the mandrel. It is in the eccentric position within.

  According to the invention of the planar burnishing tool according to claim 2, the eccentric center of the tip portion of the mandrel is at an eccentric position within the length of the radius of the tip portion from the center line of the mandrel. Is rotated, the tip portion of the mandrel revolves at an eccentric position within the length of the radius of the tip portion from the center line of the mandrel, and burnishing is performed. The work surface of the burnished workpiece is the entire locus circle whose radius is the length obtained by adding the radius of the tip of the mandrel to the eccentric length from the rotation center of the planar burnishing tool. For this reason, an unprocessed surface does not exist in the circular processed surface burnished.

  The planar burnishing tool according to claim 3 is the planar burnishing tool according to claim 1, wherein the eccentric center of the tip portion is a length of a radius of the tip portion from a center line of the mandrel. It is characterized by being in an eccentric position within half of that.

  According to the invention of the burnishing tool for a plane according to the third aspect, it is possible to further reliably process the non-machined surface within the burnished circular workpiece surface.

  The invention of the burnishing method according to claim 4 is a burnishing method using the planar burnishing tool according to any one of claims 1 to 3, wherein the burnishing method is formed at a tip of the mandrel. Burning is performed by pressing the pressing portion against a work surface of the workpiece and rotating the pressing portion eccentrically.

  According to the invention of the burnishing processing method according to claim 4, the planar burnishing tool is obtained by pressing the pressing portion at the tip of the mandrel against the work surface of the workpiece, and rotating the tip surface eccentrically to perform burnishing. When rotating and burnishing, machining is performed while revolving so as to draw a locus circle whose radius is the length from the center of rotation to the maximum outer diameter portion of the planar burnishing tool. For this reason, the occurrence of an unprocessed portion in the processed circle is eliminated, and a narrow portion can be processed.

  The invention of the burnishing method according to claim 5 is the burnishing method according to claim 4, wherein the pressing portion is pressed against a bottom surface of a groove formed in the workpiece, and the pressing portion is eccentric. It is characterized by being burned by moving while rotating.

  According to the invention of the burnishing processing method of the fifth aspect, the pressing portion at the tip of the mandrel is pressed against the bottom surface of the groove of the workpiece, and the pressing portion is moved while being eccentrically rotated to perform various burnishing processes. The bottom surface of the shaped groove can be processed.

  According to the planar burnishing tool and the burnishing method according to the present invention, it is possible to provide a planar burnishing tool and a burnishing method capable of burnishing a narrow flat end groove bottom surface and a small-diameter circular end surface.

Hereinafter, a planar burnishing tool and a burnishing method according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a half sectional view showing a planar burnishing tool according to an embodiment of the present invention.
Before describing the planar burnishing tool 1 shown in FIG. 1, a processing machine (not shown) and a workpiece W (see FIG. 5A) to which the planar burnishing tool 1 is attached will be described.

≪Processing machine configuration≫
The processing machine (not shown) is a machine tool for attaching and rotating the planar burnishing tool 1 to the drive unit, for centering the workpiece W (see FIG. 2) and the planar burnishing tool 1, and for planar use. It consists of a machine capable of giving rotation and feed to the burnishing tool 1. The processing machine is, for example, a machining center, a lathe, a general-purpose milling machine, or the like that performs cutting by rotating a detachable tool. The processing conditions for burnishing with the planar burnishing tool 1 by this processing machine are, for example, a peripheral speed of about 50 to 200 m / min and a feed speed of 0.05 to 0.1 mm / rev. The pressing amount is about 0.1 to 0.2 mm. In addition, when the plane burnishing tool 1 is attached to the processing machine and burnishing is performed, the processing pressure, the rotation speed, and the feeding speed are gradually increased under appropriate processing conditions.

≪Work structure≫
A workpiece W (see FIG. 5A) processed by the planar burnishing tool 1 shown in FIG. 1 is, for example, a metal material having a hardness (HRC) of 40 or less and a surface roughness before burnishing of about Rmax 2 μm. For example, it is a member such as steel, aluminum alloy, copper alloy, die-cast material (aluminum alloy, zinc alloy, magnesium alloy, etc.). The workpiece W includes a flat plate member, a small-diameter end surface Wd ′ (see FIG. 7) such as a circle, a groove We (see FIG. 5A) having a flat bottom surface Wc, and a work surface Wa such as a step surface. For example, engine parts such as automobiles, hydraulic / pneumatic equipment, molds, and the like. The to-be-processed surface Wa is, for example, a flat end surface O-ring groove formed on a flat end surface for inserting an O-ring or a portion to which a sealing material such as an oil seal groove is attached.
Hereinafter, a case where the flat bottom surface Wc in the narrow groove We of the workpiece W (see FIGS. 5A and 5C) is narrow will be described as an example.

≪Configuration of burnishing tool for flat surface≫
As shown in FIG. 1, the planar burnishing tool 1 is smooth like a mirror surface by pressing the tip 2f of a mandrel 2 against the surface (plane) of a metal workpiece W (see FIG. 2) and plastically deforming it. A tool that burnishes the finished surface. The planar burnishing tool 1 is mounted on a spindle or table of a processing machine (not shown), rotates, presses the workpiece W, and performs a buffing process. In particular, the planar burnishing tool 1 is formed on a flat surface of the workpiece W. This is optimal for processing the bottom surface Wc (see FIG. 5A) of the groove Wed and the small-diameter end surface Wd ′ (see FIG. 7) described later.

The planar burnishing tool 1 includes a cylindrical shank 3 mounted on a processing machine (not shown), a mandrel 2 that is inserted into and supported by the shank 3, and rotates together with the shank 3. A key 4 inserted into a key groove 3c formed on the tip end side in the hole 3a and a key groove 2b formed on the outer peripheral surface of the mandrel 2 to rotate the mandrel 2 integrally with the shank 3; A spring (biasing means) SP for urging the mandrel 2 in the direction of and an urging force adjusting means 5 for adjusting the urging force generated by the spring SP.
In addition, when burnishing the workpiece | work W with the plane burnishing tool 1, it is performed, supplying a working fluid. The working fluid is intended for lubrication, cleaning, and cooling, and is made of, for example, oily, water-soluble, or emulsion.

≪Mandrel configuration≫
As shown in FIG. 1, the mandrel 2 is a member having a pressing portion 2 a at the tip for burnishing by pressing and moving the work surface Wa of the workpiece W (see FIG. 2). It is made of a hard material such as metal. The mandrel 2 is inserted into the installation hole 3a of the shank 3 (see FIG. 1), and is coupled by the key 4 so as to rotate integrally in the shank 3. The mandrel 2 has a stepped portion in which a pressing portion 2a is provided at a distal end portion 2f, a spring receiving portion 2c for supporting a spring SP at a proximal end portion, a key groove 2b (see FIG. 3) and a hook-shaped stopper 2d are integrally formed on an outer side surface. It has a cylindrical shape. The mandrel 2 is formed into a substantially cylindrical shape with a thick side inserted into the installation hole 3a of the shank 3 to form a mandrel main body, and has a thin cylindrical shape with a tip side with the pressing portion 2a protruding from the mandrel main body. ing.

  The mandrel 2 formed in this manner is inserted into the installation hole 3a from the base end side of the shank 3 and the spring 2 is interposed between the spring SP, the guide 6 and the spacer 7 with the stopper 2d locked to the stepped portion 3d. Thus, the adjustment screw N1 is screwed into the female screw portion 3e, so that the adjustment screw N1 is elastically pressed toward the distal end side and is movable in the proximal end side so as to be installed in the installation hole 3a. The mandrel 2 is connected to the shank 3 by a key 4 so as to be linearly moved (retracted) along the center line Oa-Oa.

  FIG. 2 is an enlarged view of a portion X shown in FIG. FIG. 3 is a front view showing the planar burnishing tool according to the embodiment of the present invention. FIG. 4 is a front view showing the planar burnishing tool according to the embodiment of the present invention.

As shown in FIG. 2, the tip 2f of the mandrel 2 is, for example, a portion that is formed in a columnar shape with a diameter of about 2.5 mm to form the pressing portion 2a, and a radius is formed on the outer peripheral edge 2e. ing.
As shown in FIG. 3, the tip 2 f of the mandrel 2 is installed with an eccentric length L shifted from the rotation center Oa of the planar burnishing tool 1. The eccentric center Ob of the tip 2f of the mandrel 2 is located within the radius Ra of the radius of the tip 2f from the center line Oa-Oa of the mandrel 2. The length L (the amount of eccentricity) is, for example, 0.5 mm.

  As shown in FIG. 2, the pressing portion 2 a is a portion that presses and processes the work surface Wa of the workpiece W, and includes a flat surface portion formed on the tip portion 2 f of the mandrel 2. The pressing portion 2a has a flat portion with a diameter Da of, for example, about 1.7 mm. When the pressing portion 2a is rotated by the rotation of the processing machine, the length obtained by adding the eccentric length L and the length of the radius Ra of the tip portion 2f of the mandrel 2 as shown in FIG. By rotating so as to draw a locus circle having a radius as a radius, the circular machining range of the workpiece W having a diameter Db (for example, 2.7 mm) is burnished.

The spring receiving portion 2c is a portion that supports the spring SP while the tip end side of the spring SP is in pressure contact to receive a spring force.
The stopper 2d is a portion where the mandrel 2 urged toward the workpiece W by the spring SP abuts against the stepped portion 3d of the shank 3 and is prevented from moving, and is formed in a flange shape.

≪Shank configuration≫
A shank 3 shown in FIG. 1 is a substantially cylindrical member attached to a drive unit of a machine tool (not shown), and constitutes a main body of the planar burnishing tool 1. The shank 3 has an installation hole 3a drilled on the center line Oa-Oa, a lateral hole 3b drilled to connect to the installation hole 3a from the outer side surface, and a base end side in the installation hole 3a. It has the formed female screw part 3e and the groove | channel 3f formed in the circumference | surroundings of the installation hole 3a of a base end surface.

  The installation hole 3a is a hole drilled along the center line Oa-Oa with the center line Oa-Oa of the shank 3 as the center. The installation hole 3a is formed in the outer periphery of the mandrel 2 in the installation hole 3a. A step portion 3d to which the stopper 2d is engaged and a female screw portion 3e to which the male screw portion N1b of the adjusting screw N1 is screwed are formed. In the installation hole 3a, a mandrel 2, a key 4, a spring SP, a guide 6, a spacer 7, and an adjustment screw N1 are provided from the front end side.

A set piece 9 and a screw member N2 are inserted into the horizontal hole 3b.
The groove 3f is a scale for preloading when the urging force of the mandrel 2 is adjusted by being screwed into the female screw portion 3e of the adjusting screw N1 and rotating. For example, the groove 3f is radially 8 centered on the installation hole 3a. It consists of a plurality of elongated V-shaped grooves formed in an equally divided state (see FIG. 4).

≪Key structure≫
As shown in FIGS. 1 and 3, the key 4 is a quadrangular columnar member that allows the shank 3 and the mandrel 2 to rotate together while the planar burnishing tool 1 is rotating. The key grooves 2b and 3c formed in the mandrel 2 and the shank 3 are inserted.

≪Configuration of biasing force adjustment means≫
The urging force adjusting means 5 shown in FIG. 1 adjusts the urging force of the spring SP that constantly presses the mandrel 2 to the work W side. If the adjusting screw N1 is screwed to the mandrel 2 side, the mandrel 2 is pressed. The urging force of the spring SP is increased, and the urging force of the spring SP is weakened if the adjusting screw N1 is loosened so as to move away from the mandrel 2 side.
The urging force adjusting means 5 supports a spring SP that presses the mandrel 2 disposed in the installation hole 3a of the shank 3 toward the distal end side, and supports the base end side of the spring SP so as to freely advance and retreat into the installation hole 3a. The inserted guide 6, the adjusting screw N1 for moving the guide 6 back and forth to a desired position, the spacer 7 interposed between the adjusting screw N1 and the guide 6, and the urging force generated by the spring force of the spring SP. And a groove 3f serving as a scale.

<Structure of spring>
The spring SP shown in FIG. 1 is a preload processing pressure spring that presses the mandrel 2 toward the tip, and is made of, for example, a coil spring that bends about 5 mm at a load of 85 to 170 N. The spring SP is inserted between the shank 3 and the guide 6 in the installation hole 3a so as to be stretchable. The spring SP is supported in a state in which the distal end side is in pressure contact with the spring receiving portion 2 c of the shank 3, and is supported in a state in which the base end portion side is in pressure contact with the spring receiving portion 6 a of the guide 6. The spring receiving portion 2c is formed on the base end surface of the mandrel 2, and has a cylindrical convex portion protruding on the center line Oa-Oa.

<Guide structure>
The guide 6 is a substantially disk-shaped member that supports the spring SP so as to expand and contract along the center line Oa-Oa, and is installed in the installation hole 3a so as to freely advance and retract. This guide 6 has a spring receiving portion 6a in which a cylindrical convex portion that supports the spring SP is formed at the center of the surface on the tip side.

<Spacer configuration>
As shown in FIG. 1, the spacer 7 is a member for transmitting the movement of the adjusting screw N1 to the guide 6, and is composed of a cylindrical member (sleeve) that is installed in the installation hole 3a so as to be able to advance and retract. The spacer 7 is interposed between the adjusting screw N1 and the guide 6 while being elastically pressed by the spring force of the spring SP. When the adjusting screw N1 is rotated, the center line Oa of the adjusting screw N1 is interposed. It is provided in the installation hole 3a so as to move along the center line Oa-Oa together with the movement in the -Oa direction.
The spacer 7 may be formed integrally with the guide 6 or the adjustment screw N1.

<Configuration of adjustment screw>
The adjustment screw N1 is a screw for adjusting the urging force of the spring SP by screwing into a female screw portion 3e formed in the opening end portion on the base end side of the installation hole 3a, and adjusting the urging force of the spring SP. It is formed from a set screw. The adjustment screw N1 has a flat distal end surface that presses against the spacer 7 on the distal end side, a hexagonal hole N1a in which a tool such as a hexagon wrench is engaged, and a male threaded portion N1b on the entire outer peripheral side surface. Is formed. The male screw portion N1b is in contact with the tip of the set piece 9 so that the adjusting screw N1 does not move due to vibration or the like.

≪Configuration of fixing means≫
The fixing means 8 is a member for preventing the adjustment screw N1 of the urging force adjusting means 5 from moving and holding it at a predetermined position, and is composed of, for example, a set piece 9 and a screw member N2.
The set piece 9 is formed of a columnar, relatively soft metal member or the like that is inserted into the horizontal hole 3b so as to freely advance and retract. The set piece 9 is provided in the horizontal hole 3b in a state in which the end surface on the axial center side abuts on the male screw portion N1b of the adjustment screw N1 and the outer end surface is pressed by the screw member N2.
The screw member N2 is formed of, for example, a hexagon socket set screw similar to the adjustment screw N1, and is installed in a state of being immersed in the lateral hole 3b.

[Action]
Next, operations of the planar burnishing tool and the burnishing method according to the embodiment of the present invention will be described mainly with reference to FIGS. 1, 5A, 5B, 6C, and 6. FIG.
5A and 5B are diagrams illustrating a planar burnishing tool and a burnishing method according to an embodiment of the present invention, in which FIG. 5A is a cross-sectional view of a workpiece having a stepped portion, and FIG. 5B is a burnishing portion Y of FIG. The enlarged view which shows the state at the time of processing, (c) is sectional drawing of a ZZ line. FIG. 6 is an enlarged cross-sectional view taken along the line ZZ in FIG.

<Pre-processing before burnishing>
As shown in FIGS. 5A, 5 </ b> B, 5 </ b> C, and 6, when the finishing accuracy of the work surface Wa of the workpiece W is to be accurate, the work surface Wa is performed before burnishing. The flatness is finished by cutting or the like within 0.02 mm. Moreover, when the finished surface roughness is set to 3.2 S or less with the planar burnishing tool 1, it is desirable to process the roughness of the surface Wa to be processed to about 6.3 S to 12.5 S in advance.

<Fixing the workpiece and attaching the burnishing tool for flat surfaces>
The workpiece W shown in FIG. 5A is firmly fixed to a table of a processing machine (not shown) such as a machining center. After the plane burnishing tool 1 is attached to the processing machine, the plane burnishing tool 1 is brought close to the workpiece surface Wa of the workpiece W, and the rotation center Oa of the plane burnishing tool 1 and the workpiece surface Wa of the workpiece W are set. Match the center. Thereby, the rotation center Oa of the planar burnishing tool 1 becomes the rotational axis of the planar burnishing tool 1.

<When burnishing a workpiece with a step-shaped part>
As shown in FIGS. 5A, 5 </ b> B, 5 </ b> C, and 6, the planar burnishing tool uses the bottom surface Wc in the groove (stepped shape portion Wb) that is lowered by one step from the surface of the workpiece W as the processing surface Wa. No. 1 will be described for the case where burnishing is performed.
In this case, first, as shown in FIG. 5 (b), the tip of the mandrel 2 of the planar burnishing tool 1 is brought into contact with the work surface Wa.
Thereafter, as shown in FIG. 6, the plane burnishing tool 1 is rotated under appropriate machining conditions, the tip surface of the mandrel 2 is pressed against the machining start position of the work surface Wa of the workpiece W, and feed is applied. The tip surface 2f is eccentrically rotated while oiling is applied to burnt the surface Wa to be processed in the groove We.

More specifically, if the tip of the mandrel 2 is located at the position of the pressing portion 2a indicated by hatching in FIG. 5 (c) at the start of machining, the plane burnishing tool 1 Eccentric rotation about the rotation center Oa (Ow) so as to move from the position of the solid-line tip portion 2f to the tip portions 2f1, 2f2, and 2f3 (see FIG. 6) indicated by two-dot chain lines to draw a locus of an eccentric circle The workpiece W is moved while being moved in the direction of arrow a, and the bottom surface Wc of the step-shaped portion (groove We) Wb is burnished.
And if the to-be-processed surface Wa is mirror-finished in the desired state by the press part 2a of the mandrel 2, the mandrel 2 will be spaced apart from the workpiece | work W, rotation of the plane burnishing tool 1 will be stopped, and a process will be complete | finished.

  At this time, the workpiece is adjusted by adjusting the pressing amount by which the pressing portion 2a of the mandrel 2 burnishes the surface of the workpiece W with the biasing force adjusting means 5 and the stroke amount of the spindle of the machine tool. The irregularities on the surface of W are plastically deformed by a predetermined pressing amount, and the surface of the workpiece W is mirror-finished in a circular shape. Since the planar burnishing tool 1 incorporates a spring SP for adjusting the processing pressure, the spring SP can absorb variations in the dimension of the work surface Wa of the workpiece W, and can provide a constant urging force (thrust). To occur. The workpiece W machined in this way is finished to a mirror-finished surface Wa by the burnishing process, and at the same time, the hardness of the machined surface is improved, and a finished surface having a high density and excellent durability can be obtained. By providing the urging force adjusting means 5 in this way, the plane burnishing tool 1 does not require a lens window precision positioning mechanism or the like that is generally used, and thus the internal configuration can be simplified.

The workpiece surface Wa of the workpiece W machined by the planar burnishing tool 1 is, for example, a mirror surface having a surface roughness Rmax of about 2 μm before the burnishing and a surface roughness of about Rmax 0.3 μm (0.80 μm or less). Can be finished.
As a result of the burnishing, the step-shaped portion Wb (groove) of the workpiece W, which has conventionally been impossible to be burnished, is improved in the surface roughness of the bottom surface Wc, thereby improving the sealing performance. The In addition, since the workpiece W is pressed and burned by the mandrel 2, the pressed portion Wd, which is the processing surface Wa, is plastically processed, so that the strength of the workpiece W is higher than that of cutting or grinding. Is improved.

<When burnishing the small-diameter end face of the workpiece>
FIG. 7 is a view showing the planar burnishing tool and the burnishing method according to the embodiment of the present invention, and is an enlarged view of a main part showing a state when the small-diameter end face of the workpiece is burnished.
Next, as shown in FIG. 7, for example, when the entire surface of the small-diameter end face Wd ′ having a width of about 2.7 mm that cannot be held by a lathe chuck (not shown) is burned. Will be explained.

  In this case, as shown in FIG. 7, the planar burnishing tool 1 is rotated under appropriate machining conditions, and the tip surface of the mandrel 2 is turned to the machining start position of the workpiece surface Wa ′ (small-diameter end surface Wd ′) of the workpiece W ′. The workpiece surface Wa is burnished by eccentrically rotating the pressing portion 2a on the tip surface while lubricating the working fluid.

  Then, the distal end portion 2f is eccentric so as to draw an eccentric circle at a position separated from the rotation center Oa of the planar burnishing tool 1 by the length L of the radius, as in the distal end portions 2f, 2f1, 2f2, 2f3 shown in FIG. Rotating and moving, the pressing portion 2a burnishes the entire eccentric circle. At this time, the pressing portion 2a can be burnished by pressing while rotating eccentrically without leaking the entire surface of the small-diameter end surface (work surface Wa ') Wd' of the workpiece W '. For this reason, it is possible to eliminate the occurrence of the unprocessed portion W3b (see FIG. 10B) inside the processing surface Wa 'processed into an eccentric circle.

  The processed portion of the mandrel 2 includes a pressing portion 2a formed with a flat surface, and the outer side of the pressing portion 2a is an outer peripheral edge 2e that forms a rounded shape. During processing, only the pressing portion 2a of the mandrel 2 is pressed on the entire surface of the work surface Wa of the workpiece W ′, and the outer peripheral edge 2e can minimize contact with the small-diameter end surface (work surface Wa ′) Wd ′. Therefore, the occurrence of sagging can be minimized.

  In addition, when processing only by rotation without sending the plane burnishing tool 1 in this way, the unprocessed portion of the inner bottom surface of the circular groove (hole) or the ring-shaped step surface in the circular hole is minimized. Can be burned.

<Adjustment of biasing force>
Next, the action of the biasing force adjusting means 5 for adjusting the biasing force generated by the spring (biasing means) SP that biases the mandrel 2 will be described with reference to FIG.
As shown in FIG. 1, the mandrel 2 is urged toward the distal end side by the spring force of the spring SP, and the stopper 2d is engaged with the step portion 3d in the installation hole 3a, so that the urging force (pressing force) is applied. Have. The urging force can be increased or decreased by loosening the screw member N2 of the fixing means 8 and rotating the adjustment screw N1 with a tool such as a wrench.

  In this case, the biasing force of the spring SP that presses the mandrel 2 is adjusted by adjusting the preload by the spring SP built in the shank 3. The preload is set such that a predetermined surface roughness can be obtained when the stopper 2d is pushed by about 0.1 to 0.2 mm from the zero position of the mandrel 2 in contact with the step 3d. Is optimal.

For example, if the adjustment screw N1 is rotated clockwise, the adjustment screw N1 presses and moves the guide 6 toward the distal end side via the spacer 7 to compress the spring SP. As a result, the spring SP has a stronger biasing force that presses the mandrel 2 toward the tip side by the amount compressed.
Then, if the adjustment screw N1 is rotated to the left side, the biasing force of the spring SP can be adjusted to be weaker.

  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.

  According to the present invention, in the above-described embodiment, as the work surfaces Wa and Wa ′ of the workpieces W and W ′ to be machined by the planar burnishing tool 1, the bottom surface Wc (see FIG. 5) of the linear groove We and the small-diameter end surface Wd. Although '(see FIG. 7) has been described as an example, the present invention is not limited to this.

  FIG. 8 is a diagram showing a work that can be machined by the planar burnishing tool and the burnishing method according to the embodiment of the present invention, where (a) is the bottom surface of the ring-shaped groove, and (b) is the curved groove. (C) is a perspective view showing a step-shaped portion formed in a hole, and (d) is a perspective view showing a bottom surface of a circular groove.

As shown in FIGS. 5 c and 6, the planar burnishing tool 1 sends, for example, a table of a processing machine (not shown) to which the workpiece W is fixed in the direction of arrow a along the workpiece surface Wa of the workpiece W. If moved, in addition to the linear groove We, the bottom surface of the ring-shaped groove We1 as shown in FIG. 8A, the bottom surface of the curved groove We2 as shown in FIG. The bottom surface of the groove of the shape, the bottom surface of the groove of any shape such as the annular groove formed on the outer peripheral surface of the cylinder, and the burnishing of the step-shaped portion We3 formed in the hole as shown in FIG. it can. Even if the table of a processing machine (not shown) to which the workpiece W is fixed is simply pressed against the workpiece Wa of the workpiece W, the circular groove (hole) We4 as shown in FIG. Burnishing can also be performed to minimize the unprocessed portion on the bottom surface.
In this way, the bottom surface of the narrow groove We having a width b (for example, about 2 mm) for providing an O-ring, an oil seal, or the like can be burnished.

It is a half sectional view showing the burnishing tool for planes concerning the embodiment of the present invention. It is an enlarged view of the X section shown in FIG. It is a front view which shows the burnishing tool for planes concerning embodiment of this invention. It is a front view which shows the burnishing tool for planes concerning embodiment of this invention. It is a figure which shows the burnishing tool for planes and the burnishing processing method which concern on embodiment of this invention, (a) is sectional drawing of the workpiece | work which has a level | step-difference part, (b) is when burnishing the Y part of (a). The enlarged view which shows a state, (c) is sectional drawing of a ZZ line. It is ZZ expanded sectional drawing of FIG.5 (b). It is a figure which shows the burnishing tool for planes and the burnishing process which concern on embodiment of this invention, and is a principal part enlarged view which shows the state when burnishing the small diameter end surface of a workpiece | work. It is a figure which shows the workpiece | work which can be processed with the burnishing tool for planes and the burnishing processing method which concerns on embodiment of this invention, (a) is the bottom face of a ring-shaped groove, (b) is the bottom face of a curved groove, (c ) Is a step-shaped portion formed in the hole, and (d) is a perspective view showing a bottom surface of a circular groove. It is a figure which shows the conventional burnishing tool for plane mirror surface finishing, (a) is a side view, (b) is a front view, (c) is a side view which shows the state at the time of the process of the workpiece | work which has a level | step difference surface, (d FIG. 4 is an enlarged side view of a main part showing a state of a work on a small-diameter end face subjected to burnishing. It is a figure which shows the burnishing tool for the conventional circular flat end mirror finishing, (a) is a side view which has a partial cross section, (b) shows the to-be-processed surface processed with the burnishing tool for circular flat end mirror finishing. It is a principal part enlarged plan view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar burnishing tool 2 Mandrel 2a Press part 2f Tip part 3 Shank 5 Energizing force adjustment means Oa Rotation center Oa-Oa Center line Ob Eccentric center Ra Length of radius of tip part SP Spring W, W 'Work Wa, Wa' Work surface Wb, Wb1 Stepped shape portion Wc Bottom surface We, We1, We2, We3 Groove

Claims (5)

A cylindrical shank mounted on a processing machine;
A mandrel that is inserted into and supported by the shank and rotates integrally with the shank;
An urging means for urging the mandrel in the direction of the workpiece disposed on the tip side of the shank;
And a biasing force adjusting means for adjusting a biasing force generated by the biasing means, and a plane burnishing tool that presses and processes the tip of the mandrel on the plane of the workpiece,
The planar burnishing tool is characterized in that the tip portion is installed eccentrically with respect to the rotation center of the planar burnishing tool.   2. The planar burnishing tool according to claim 1, wherein an eccentric center of the tip portion is located at an eccentric position within a length of a radius of the tip portion from a center line of the mandrel.   2. The planar burnishing tool according to claim 1, wherein an eccentric center of the tip portion is located at an eccentric position within half of a radius of the tip portion from a center line of the mandrel. A burnishing method using the planar burnishing tool according to any one of claims 1 to 3,
A burnishing method comprising: pressing a pressing portion formed at a tip of the mandrel against a surface to be processed of the workpiece, and performing burnishing by rotating the pressing portion eccentrically.   5. The burnishing method according to claim 4, wherein the pressing portion is pressed against a bottom surface of a groove formed in the workpiece, and the pressing portion is moved while being eccentrically rotated and burnishing is performed.

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