JP2006026800A - Lapping device and lapping film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lapping film and a lapping device which have a longer service lifetime and are capable of preventing the non-uniformity of machining and the deterioration of a machining amount caused by the positional shift of the lapping film, and also, capable of maintaining the uniformity of machining for a long period of time. <P>SOLUTION: The lapping device has a long belt-like lapping film 11, which covers the machining face of an arcuate workpiece W having a non-circular cross section and in which abrasive grains are provided on the whole face of a thin base member 11a, a rotary driving means 40 for rotationally driving the workpiece W, an oscillation means 50 for axially oscillating the workpiece W, and a recessed shoe means 70 which presses the abrasive grain face of the lapping film to the machining face of the workpiece W by a recessed shoe provided on the rear face side of the lapping film. A film holding mechanism 90, which holds at least one side end part of the lapping film 11, is provided to the recessed shoe means 70. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lapping film with abrasive grains for film lapping (hereinafter simply referred to as lapping) on a work surface of a workpiece, and a lapping apparatus.

  For example, when finishing a work having an outer peripheral surface with a circular arc cross section such as a cam lobe part or a journal part of a camshaft which is an engine part of a vehicle or a journal part or a swing pin part of a crankshaft, Wrapping is performed using a long wrapping film in the form of a belt provided with abrasive grains.

  In this lapping process, the work surface of the work is covered with a lapping film, the lapping film is pressed from the back side by a concave shoe arranged oppositely, and the work is simultaneously rotated while the lapping film is pressed against the work. This is super-finishing that oscillates (vibrates) in the axial direction and processes the workpiece with the abrasive surface of the lapping film (see, for example, Patent Document 1 below).

  In such lapping processing, the shape of the processed surface along the axial direction of the workpiece tends to be a concave shape. When the oscillation for reciprocating the workpiece in the axial direction is performed, the abrasive grain surface of the wrapping film is damaged from the edge portion of the reciprocating workpiece and the abrasive grains are quickly worn or peeled off. The abrasion and peeling of the abrasive grains occur at both outer edges of the wrapping film where the edge portion of the workpiece hits, and the number of working abrasive grains at both outer edges of the wrapping film is smaller than the number of working abrasive grains at the center. As a result, the removal amount of the work surface of the workpiece is relatively increased in the center portion as compared with both end portions, and the shape of the work surface along the axial direction of the work becomes a substantially concave shape.

  For example, if a valve lifter is operated using a cam lobe part that is unevenly worn in a concave shape, the load balance of each valve lifter acting on the cam lobe part is lost, and each valve lifter does not operate uniformly, resulting in engine operating characteristics. May change.

  In addition, when the workpiece work surface is magnified with a microscope or the like, it is not a clean circular arc with a predetermined radius of curvature, but a concave shape with a plurality of small protrusions between relatively large recesses. The desired straightness and surface roughness cannot be obtained.

  With respect to the wrapping film, when the workpiece is oscillated, there is a possibility that the position is shifted in the width direction following this. In the wrapping process, the processing amount is determined by the relative movement of the workpiece and the wrapping film. Therefore, if the wrapping film is displaced in the width direction due to oscillation, the processing amount is reduced.

In order to prevent this, the back coating of the wrapping film is back coated to increase the braking force by the shoe. However, the back coating itself is worn due to the displacement of the wrapping film, and the braking force is reduced, resulting in a shoe recess. There is a risk that entanglement and unnecessary feeding in the feeding direction will occur, processing non-uniformity and processing amount will be reduced, and product quality will be reduced.
JP-A-7-237116 (see FIGS. 1 and 2)

  The present invention has been made in order to solve the above-mentioned problems, and prevents the processing non-uniformity and processing amount from being reduced due to the positional deviation of the wrapping film, and can maintain the processing uniformity over a long period of time. It is an object of the present invention to provide a lapping apparatus and a lapping film that are particularly advantageous.

  A lapping apparatus according to the present invention that achieves the above object includes a long belt-shaped lapping film that covers a machining surface of a work having an arc shape with a non-circular cross section and is provided with abrasive grains on one surface of a thin substrate. Rotating drive means for rotating the workpiece, oscillation means for oscillating the workpiece in the axial direction, and processing of the abrasive grain surface of the wrapping film by a concave shoe provided on the back side of the wrapping film And a concave shoe means for pressing against the surface, wherein the concave shoe means is provided with a film holding mechanism for holding at least one side end of the wrapping film.

  The wrapping film according to the present invention that achieves the above object is arranged so as to cover the work surface of the work having an arc shape with a non-circular cross section, with the abrasive surface pressed against the work surface of the work by the concave shoe, A long belt-like wrapping film that rotates the workpiece and oscillates in the axial direction, and wraps the processed surface of the workpiece. The concave / convex fitting portion to be mated is provided on at least one side end portion.

  In the lapping apparatus according to the present invention configured as described above, since at least one side end of the wrapping film is held by the film holding mechanism, a positional shift that occurs in the processed part of the wrapping film during the axial oscillation of the workpiece. Can be prevented. As a result, it is possible to prevent the processing non-uniformity due to the positional deviation, maintain good processing over a long period of time, and improve the product quality.

  The wrapping film according to the present invention configured as described above has a concave-convex fitting portion that fits with the outer periphery of the holding roller. Therefore, diamond electrodeposition as an anti-slip provided on the back side in contact with the concave shoe. No processing or back coating is required, and the cost of the wrapping film itself can be reduced. In addition, it is reliably sent without deviation, and it is possible to prevent processing defects or non-uniformity of processing due to slackness and maintain good processing over a long period of time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a schematic view of the lapping apparatus, FIG. 2 is a schematic cross-sectional view taken along line 2-2 of FIG. 1, and shows a closed state of the upper and lower arms of the lapping apparatus, and FIG. 3 shows an open state of the upper and lower arms. FIG. 4 is a schematic cross-sectional view, FIG. 4 shows a workpiece of the present embodiment, (A) is a perspective view of the workpiece, and (B) is an explanatory view of a main part of the workpiece. Note that the workpiece axial direction (left-right direction in FIG. 1) is the X direction, the horizontal direction orthogonal to the X direction (perpendicular direction in FIG. 1) is the Y direction, and the vertical direction orthogonal to the X direction (up and down direction in FIG. 1). Is defined as the Z direction.

  1 and 2, the wrapping processing apparatus 1 will be briefly described. A wrapping film 11 in which abrasive grains are provided on one surface of a non-stretchable and deformable thin base material, a back side of the wrapping film 11, A concave shoe means 70 for pressing the abrasive grain surface of the wrapping film 11 against the workpiece W by a shoe 3 (hereinafter referred to as a concave shoe 3) whose shape of the portion is made concave in the rotation direction of the workpiece W, and the workpiece W is rotationally driven. Rotation driving means 40 and oscillation means 50 for oscillating the workpiece W in the axial direction. A plurality of wrapping films 11 and concave shoe means 70 are provided in the axial direction of the camshaft 60 that is the workpiece W. Each provided cam lobe portion 61 is provided to be individually lapped.

An example of the workpiece W is the camshaft 60 shown in FIG. 4A, and the cam lobe portion 61 of the camshaft 60 serves as a machining surface. As shown in FIG. 4B, the cam lobe portion 61 generally has a substantially oval non-circular arc-shaped peripheral surface, and defines a base portion d that forms a base circle, and a cam lift. The top part a, continuous on both sides of the top part a, the event part b ₁ , b ₂ that starts opening or closing the valve of the engine, and the ramp that approaches the event part b ₁ , b ₂ from the base part d A plurality of portions c ₁ and c ₂ are provided, and the radius from the axis O (rotation center) to the machining surface changes for each portion.

The radius of curvature of each part is constant at the base part d but very large because the event parts b ₁ and b ₂ are substantially linear, the top part a is relatively small, and the cam lobe part 61 is at the top part a. The most frictional force is generated.

  Here, the “non-circular arc shape” refers to an arc shape in which the radius from the center of rotation to one part is different from the radius to the other part, such as an elliptical shape or an egg like the cam lobe portion 61 shown in the figure. Of course, the shape is included, and the outer shape is circular but the center of rotation is eccentric from the center of the circle.

Further, the lapping apparatus 1 will be described in detail. In FIG. 1, the rotation drive means 40 includes a head stock 42 that rotatably supports a main shaft 41, a chuck 43 that is provided at the tip of the main shaft 41 and grips one end of a camshaft 60 that is a workpiece W, and a main shaft 41. a spindle motor M ₁ which is connected via a belt 44, and a tailstock 46 provided with a center 45 for supporting the other end of the camshaft 60.

Camshaft 60, the rotation of the spindle motor M ₁ is transmitted through the belt 44 and the main shaft 41, by changing the rotational speed of the spindle motor M _1, the workpiece rotational speed is set to the desired speed, the workpiece during machining The rotational position of W is detected by a rotary encoder S ₁ attached to the main shaft 41.

  The head stock 42 and the tail stock 46 are respectively provided on tables 47 and 48 that are slidable along the Y direction. The tables 47 and 48 are placed on a table 49 that is slidable along the X direction. Has been.

The oscillation means 50 includes an eccentric rotator 51 that contacts the end surface of the table 49, an oscillation motor M ₂ that rotationally drives the eccentric rotator 51, and a spring that always contacts the end surface of the table 49 with the eccentric rotator 51. Etc., and elastic means 52 such as.

The oscillation speed Vo is set to a desired speed (for example, 10 Hz) by changing the rotational speed of the motor M ₂ , and the amplitude is set to the eccentric amount of the eccentric rotating body 51 with respect to the axis of the oscillation motor M _2. Set based on. In this embodiment, the amount of eccentricity is about 1 mm, and the oscillation width is about 2 mm. Change in the X-direction position of the cam shaft 60 due to the oscillation is attached a rotary encoder S ₂ for detecting the rotational position of the eccentric rotor 51 to the shaft of the eccentric rotor 51, is detected.

  For adjusting the eccentric amount of the eccentric rotating body 51, for example, known means such as changing the number of inserted adjustment plates (not shown) may be used in combination.

  FIG. 5 is a schematic view of the concave shoe portion, and FIG. 6 is a schematic cross-sectional equivalent view taken along line 6-6 of FIG.

  The concave shoe 3 is made of, for example, metal, ceramic, or a hard urethane resin excellent in oil resistance and water resistance (for example, a polyether-based urethane prepolymer).

  As shown in FIG. 5, the shape of the tip of the concave shoe 3 is such that a concave portion 3b is formed at the center, and the center line passing through the swing pin 29 is symmetrical with the center line passing through the swing pin 29 so as to be smoothly connected to the concave portion 3b. A circular arc surface 3a having a symmetrical convex cross section is formed. Therefore, when each concave shoe 3 is pressed against the processing surface of the cam lobe portion 61, the upper and lower concave shoes 3 are in line contact with the processing surface of the cam lobe portion 61 at two points, though the wrapping film 11 is interposed therebetween. Is pressed against the cam lobe portion 61, the cam lobe portion 61 comes into contact with the cam lobe portion 61 at a total of four points, and the cam lobe portion 61 rotates stably. In the present specification, the indirect contact of the concave shoe 3 with the processed surface of the workpiece W via the wrapping film 11 may be abbreviated as “contact”.

As shown in FIG. 6, the axial width M of the concave shoe 3 is equal to the width w ₁ of the processed surface of the workpiece W so that it does not deviate from the concave shoe 3 even if the workpiece W oscillates in the axial direction. has been determined taking into account the w _0.

  On the other hand, the wrapping film 11 has various types. In this embodiment, the thin base material 11a is made of a material having high non-stretch properties, for example, a polyester having a thickness of about 25 μm to 130 μm. A large number of abrasive grains (specifically, made of aluminum oxide, silicon carbide, diamond, or the like) having a particle diameter of about several μm to 200 μm are uniformly attached to the inner surface of the adhesive by an adhesive.

As shown in FIGS. 2 and 3, the wrapping film 11 is pulled out from the supply roller 15 in the upper part of the drawing and is provided with a pair of first guide rollers R ₁ provided at the tip of the upper arm 22, A second guide roller R ₂ attached to the lower position, a third guide roller R ₃ attached to the inner position of the lower arm 23, and a pair of fourth guide rollers provided at the tip of the lower arm 23. Guided by R ₄ or the like and wound on the winding roller 16.

A motor M ₃ is connected to the winding roller 16. When the motor M ₃ is operated to rotate the winding roller 16, the wrapping film 11 is sequentially fed from the supply roller 15. Out amount of the lapping film 11 is performed by detecting the amount of rotation by the rotary encoder S ₃ attached to the shaft of the take-up roller 16. It should be noted that the tension of the wrapping film 11 is applied locking device provided in the vicinity of the feed roller 15 and the take-up roller 16 (not shown) by the operation of the motor M _3.

  The upper arm 22 and the lower arm 23 that make a pair are relatively openable and closable in the Z direction with the support pin 24 as a center, and a fluid pressure cylinder that is operated by hydraulic pressure or pneumatic pressure at the rear end portion of the upper arm 22. One end of 25 is pin-connected, and the tip of the rod 26 is pin-connected to the rear end of the lower arm 23.

  When the rod 26 is extended by the fluid pressure cylinder 25, the upper and lower arms 22 and 23 are in the closed state shown in FIG. 2, and when they are contracted, the upper and lower arms 22 and 23 are in the open state shown in FIG. The upper and lower arms 22, 23 are pivoted around the support pin 24 together with the wrapping film 11, and the closed shoe 3 is brought into contact with the cam lobe portion 61 via the wrapping film 11 by the closing pivot and is pivoted open. As a result, the contact between the cam lobe portion 61 and the concave shoe 3 is released.

The motors M ₁ , M ₂ , M ₃ , M ₄ and the rotary encoders S ₁ , S ₂ , S ₃ are connected to a controller 200 (see FIG. 1) mainly composed of a CPU and a memory. The controller 200 controls the motors M ₁ , M ₂ , M ₃ , and M ₄ while monitoring the detection results of the rotary encoders S ₁ , S ₂ , and S ₃ . Controls the operation of each component.

The wrapping film 11 pulled out in this way is guided from the supply roller 15 to the take-up roller 16, but is only guided by the guide roller in the middle thereof, and a force is exerted in the width direction at the portion where the workpiece W is processed. When it acts, there is nothing that restricts positional deviation. Also, the width L is determined in consideration of the processed surface width w ₁ of the workpiece W, the oscillation width w ₀ (about 2 mm), and the allowance δ, as shown in FIG. However, it cannot be made unnecessarily large due to downsizing of the apparatus or cost.

  Therefore, the wrapping film 11 may cause a positional deviation in which a force is applied from the lateral direction in the processed portion of the workpiece W as in oscillation.

  When the workpiece W is oscillated in the axial direction, the contact distance between the workpiece W and the abrasive grains is increased, the number of working abrasive grains per unit time with respect to the workpiece W is increased, the machining time is shortened, and the machining efficiency of the workpiece is increased. be able to. However, when the workpiece surface is formed by lapping, the workpiece W having both edge portions of the cam lobe portion 61 having a substantially 90-degree edge portion is machined. The part hits the wrapping film 11 and the abrasive grains 4 are peeled off or dropped, and a large force acts in the axial direction during oscillation, and the wrapping film 11 may be displaced due to this force. When misalignment occurs, the number of the working abrasive grains decreases, the processing amount decreases, and the processing becomes uneven.

  For this reason, in this embodiment, in order to prevent displacement of the wrapping film 11, a film holding mechanism 90 that holds the wrapping film 11 in a fixed position is provided in the concave shoe means 70.

  7 is a schematic view of the concave shoe means of the present embodiment, FIG. 8 is a schematic plan view taken along line 8-8 of FIG. 7, and FIG. 9 is a schematic cross-sectional view taken along line 9-9 of FIG.

  The concave shoe means 70 has a shoe case 28 as shown in FIG. 7, and this shoe case 28 is a concave portion provided at the tip of the arms 22 and 23 as shown in FIGS. 27 can be moved up and down by a spring 33. The shoe case 28 may be displaced up and down in the recess 27 by a moving means (not shown) for moving up and down a pressing bar biased by a motor-driven cam. In this case, the swing pin 29 is fitted into each arm 22, 23 with a long hole.

  In FIG. 7, the concave shoe 3 is supported in the shoe case 28 so as to swing as the work W rotates around the swing pin 29, and the film holding mechanism 90 is supported on the concave shoe 3. Is provided.

  When the film holding mechanism 90 is provided in the closest position of the concave shoe 3 as described above, the wrapping film 11 can be held at the closest position of the processed portion, and not only the positional deviation of the wrapping film 11 can be easily prevented, but also the concave shoe means 70. The overall structure can be made more compact, which is preferable. In addition, in the conventional wrapping film 11, the other surface of the thin base material 11 a is back-coated with a resistance material (not shown) such as rubber or synthetic resin in order to prevent slipping with the concave shoe 3, Alternatively, the anti-slip process is performed. However, if the wrapping film 11 is held by the film holding mechanism 90 as in the present embodiment, the wrapping film 11 can be held at a position closest to the concave shoe 3, and such an anti-slip process is unnecessary. This is extremely advantageous in terms of cost.

  More specifically, the film holding mechanism 90 includes a pair of holding rollers 91 that guides and holds the wrapping film 11 in a fixed manner, a stopper mechanism 93 that controls the rotation of the holding roller 91, and the holding rollers 91. And a pressing mechanism 97 that prevents the interval therebetween from narrowing.

  As shown in FIGS. 7 and 9, a total of four holding rollers 91 are provided, two on each side of the concave shoe 3. Each holding roller 91 has the same outer diameter and is rotatably supported by a shaft 92 protruding from the concave shoe 3. The pair of holding rollers 91 facing each other with the concave shoe 3 in between are coaxial. Provided.

  Each holding roller 91 has a so-called gear shape, and a large number of protrusions t are formed at equal intervals on the outer peripheral surface. A part of the outer peripheral surface of the holding roller 91 has a shape along the arc surface 3 a of the concave shoe 3. As shown in FIG. 8, the protrusion t is fitted with through holes or recesses (hereinafter collectively referred to as recesses r) formed at both end portions of the wrapping film 11.

  If the projection t and the recess r are fitted in this way, when the wrapping film 11 is set, it is easy to set the shape along the concave shape of the tip of the concave shoe 3, which is preferable from the viewpoint of processing.

  Further, when the holding roller 91 is rotated, the projections t and the recesses r are fitted on both sides in the width direction of the wrapping film, and the feeding on both sides of the wrapping film can be applied uniformly. The wrapping film 11 can be fed without sag in the portion 3d, and it is not misaligned and wound into the concave shoe or sent out unnecessarily, and non-uniform processing can be prevented.

  Therefore, since the wrapping film 11 is reliably held in both the feeding direction and the oscillation direction, it is possible to reliably prevent non-uniform processing due to misalignment and maintain good processing over a long period of time. it can.

  If it is not perfect and it is sufficient that the processing uniformity is maintained to some extent, two holding rollers 91 are not necessarily provided on both sides of the concave shoe 3, but two holding rollers 91 are provided only on one side or opposed to each other. Only one pair may be used. In other words, a plurality of wrapping films 11 may be provided in one of the feeding direction which is the longitudinal direction and the oscillation direction which is the width direction.

  The stopper mechanism 93 is provided at a position slightly below the holding rollers 91 on the side surface of the concave shoe 3 and is actuated by fluid pressure such as hydraulic pressure or pneumatic pressure, and a rod linearly reciprocated by the actuator 94. 95, and a frustoconical engagement member 96 provided at the tip of 95.

  The stopper mechanism 93 has a wrapping film holding function and a tension applying function. For example, when the rod 95 is protruded by the actuator 94 and the sharpened end portion 96a of the engaging member 96 is inserted between the protrusions t of the holding rollers 91, the engaging roller 96 is engaged with the protrusions t. The rotation is prevented and the wrapping film 11 is held in a fixed position.

  Further, when the actuator 94 projects the rod 95 and the pointed portion 96a rotates the holding roller 91 in the opposite directions via the projection t, the wrapping film 11 between the both holding rollers 91 can be tightly stretched, Tension can also be applied.

  Therefore, the stopper mechanism 93 of the present embodiment exhibits a holding function and a tension applying function of the wrapping film 11, and is an extremely compact mechanism as compared with the case where those that exhibit these functions are provided separately. However, the present invention is not limited to this, and it goes without saying that the holding of the wrapping film 11 and the application of tension to the wrapping film 11 may be performed by different mechanisms.

  As shown in FIG. 9, the pressing mechanism 97 is configured by providing a pair of pins 98 and a coil spring 99 in a through hole 3 c formed near the tip of the concave shoe 3. The elastic force of the coil spring 99 pushes and widens the distance between the holding rollers 91 via the pin 98, so that the wrapping film 11 is prevented from slackening due to the narrowing of the distance between the holding rollers 91. Maintain tension in direction.

  The tip of the pin 98 is preferably formed in a spherical shape or a low friction coating such as DLC (Diamond-Like-Carbon) in order to reduce friction with the rotating holding roller 91.

  Next, the operation of this embodiment will be described.

First, both the pressing arms 22, 23 is in the open each state corresponding to each cam lobe portion 61, when operating the motor M _3, the take-up roller 16 is guided in the wrapping film 1 feed roller R is rotated, a predetermined amount The wrapping film 11 having a new abrasive surface is set on the concave shoe 3 portion.

Lock the locking device provided in the vicinity of the supply roller 15, when operating the motor M _3, a certain degree of tension is applied to the lapping film 1.

  On the other hand, in the vicinity of the processing position of the workpiece W, the stopper mechanism 93 of the film holding mechanism 90 causes the pointed portion 96a of the engaging member 96 to enter between the protrusions t of the holding roller 91 by the operation of the actuator 94, and the holding roller 91 rotates. And the wrapping film 11 is held in a fixed position. Thereby, the wrapping film 11 is held in a state along the concave portion 3 b at the tip of the concave shoe 3.

  Further, in the pressing mechanism 97, the pin 98 is protruded toward the both holding rollers 91 by the coil spring 99 so that the interval between the both holding rollers 91 is not narrowed. Thereby, the slack of the wrapping film 11 in the width direction is prevented.

  When the locking device near the winding roller 16 is locked in this state, the wrapping film 11 is attached without slack.

  When the camshaft 60 which is the workpiece W is set between the head stock 42 and the tail stock 46 and the fluid pressure cylinder 25 is operated, both the pressing arms 22 and 23 are closed, and accordingly, the wrapping film 11 is moved to the workpiece W. The abrasive grain surface is pressed against each cam lobe portion 61 which is the processing surface of the workpiece W by the concave shoe 3 with a predetermined pressing force.

Upon actuation of the motor M _1, and the workpiece W is rotated, the working surface is lapped by abrasive surface of the lapping film 11. Also, when operating the motor M _2, the eccentric rotor 51 is rotated against the elastic force of the elastic means 52 to reciprocate the table 49 in the X direction, to oscillation of the workpiece W in the X direction.

  When the workpiece W is rotated about the axis, the concave shoe 3 pressed against the workpiece W swings around the swing pin 29 while moving forward and backward along the cam lobe portion 61 having a non-circular arcuate circumferential surface. While moving, lapping is performed on the abrasive surface of the lapping film 11. The camshaft 60 has a large number of cam lobes 61, which are lapped together.

  On the other hand, when the oscillation is performed, the distance between the workpiece W and the abrasive grains is increased, the number of working abrasive grains per unit time with respect to the workpiece W is increased, the machining time is shortened, and the machining efficiency of the workpiece can be increased.

  During processing, in the present embodiment, since the film holding mechanism 90 holds the wrapping film 11 at a position closest to the concave shoe 3, positional deviation of the wrapping film is suppressed.

  For example, when the workpiece W is oscillated, the protrusion t of the holding roller 91 provided so as to face the concave shoe 3 is fitted into the concave portion r and holds both sides in the width direction of the wrapping film. The positional deviation of the wrapping film is reliably prevented. Similarly, the positional deviation is prevented with respect to the feeding direction of the wrapping film 11.

  Therefore, the wrapping film 11 is not displaced in the feeding direction due to the processing resistance and is not caught in the concave shoe 3 or sent out unnecessarily, and the processing non-uniformity due to the positional deviation of the wrapping film 11 is surely prevented. Is done. Therefore, uniform lapping is performed in a good state without a reduction in the number of working abrasive grains and a reduction in the processing amount.

When the machining is completed, the motors M ₁ and M ₂ are stopped, the workpiece W is replaced, and a new workpiece W is machined. When a predetermined number of workpieces W are processed, the wrapping film 11 is fed and processed on a new surface.

  Even when the wrapping film 11 is fed, the wrapping film 11 can be fed evenly while the projections t and the recesses r are fitted on both sides in the width direction, so that the wrapping film 11 is not displaced.

  When the actuator 94 of the stopper mechanism 93 protrudes the rod 95, the pointed portion 96a rotates the holding roller 91 in the opposite directions via the projection t, and the wrapping film 11 between the holding rollers 91 is moved in the feeding direction. It can also be tightly tensioned, and when the tension is insufficient, a predetermined tension can be applied.

  As described above, according to the present embodiment, when a plurality of holding rollers 91 are provided along at least one of the feeding direction or the oscillation direction of the wrapping film 11, the positional deviation or the wrapping film in the feeding direction of the wrapping film 11 is provided. 11 positional deviation in the oscillation direction can be suppressed.

  If the holding roller 91 is pushed and expanded by the pressing mechanism 97 so that the interval between the holding rollers 91 is not narrowed, a tension can be applied to the wrapping film 11 to prevent processing defects or processing non-uniformity due to bending of the wrapping film 11. In addition, positional deviation can be further suppressed.

  If the holding roller 91 is fixed by the stopper mechanism 93 during processing of the workpiece, the wrapping film 11 is not displaced in the feeding direction of the wrapping film 11 due to processing resistance, and is not caught in the concave shoe 3 or sent out unnecessarily. Non-uniform processing can be prevented and stable processing can be performed at low cost.

  If the wrapping film 11 is pulled in the feed direction by the tension applying means before the work is processed and the tension is applied, the processing failure or the non-uniformity of processing due to the wrapping film 11 loosening can be prevented, and the wrapping film 11 is displaced. Can be further prevented.

  When the outer peripheral projection t of the holding roller 91 is fitted into the concave portion r of the wrapping film 11, the wrapping film 11 is positioned with respect to the concave shoe 3, so that the wrapping film 11 is reliably prevented from being displaced during processing of the work. In addition, it is possible to prevent processing defects or processing non-uniformity due to loosening of the wrapping film 11, and to maintain good processing and improve product quality over a long period of time.

  In the case of the wrapping film 11 having the concave portion r into which the outer peripheral projection t of the holding roller 91 is fitted, the wrapping film itself is surely sent without deviation. Back coating is unnecessary, and the cost of the wrapping film itself can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, in the above-described embodiment, the tip portion of the concave shoe 3 has a flat shape in the axial direction of the workpiece, but depending on the workpiece W, the cam lobe portion 61 may be formed in a middle convex shape. For example, in a direct-acting valve operating system in which a valve lifter is operated directly by a camshaft, the friction force acting between the camshaft and the valve lifter directly affects the fuel consumption, so the cam lobe that generates the most frictional force is used. When the vicinity of the top part of the part is made into a concave shape, the load of the valve lifter is applied to the central part of the cam lobe part, which is preferable, and the cam lobe part may be formed into a convex shape.

  In forming such a workpiece W, the tip of the concave shoe 3 is formed into an arcuate concave shape in the axial direction of the workpiece, and the workpiece W is formed into a shape along this shape.

  The present invention can be applied not only to the shape of the tip of the concave shoe 3 being flat in the axial direction of the workpiece, but also to a circular concave shape.

  Further, in the above embodiment, the protrusion t is formed on the holding roller 91 and the concave portion r is formed on the wrapping film 11, but the reverse may be used, and the concave and convex fitting portion is formed by the protrusion t and the concave portion r. I just need it.

  The present invention is suitable for lapping processing for forming a cam lobe portion of a camshaft used in an automobile engine.

It is the schematic of a lapping apparatus. It is a schematic sectional drawing in alignment with line 2-2 of FIG. 1, and is a schematic sectional drawing which shows the upper and lower arm closed state of the lapping apparatus. It is a schematic sectional drawing which shows the open state of the same up-and-down arm. The workpiece | work of this embodiment is shown, (A) is a perspective view of the workpiece | work, (B) is principal part explanatory drawing of the workpiece | work. It is the schematic of the shoe part shown in FIG. FIG. 6 is a schematic cross-sectional equivalent view taken along line 6-6 of FIG. It is the schematic of the concave shoe means of this embodiment. FIG. 8 is a schematic plan view taken along line 8-8 in FIG. 7. It is a schematic sectional drawing in alignment with line 9-9 in FIG.

Explanation of symbols

3 ... concave shoe,
3b: concave portion of the concave shoe,
11 ... Wrapping film,
11a ... Thin base material,
40: Rotation drive means,
50 ... oscillation means,
70 ... concave shoe means,
90 ... film holding mechanism,
91 ... holding roller,
93 ... Stopper mechanism (tensioning mechanism)
97 ... Pressing mechanism,
r ... recess,
t ... protrusions,
W ... Work.

Claims (8)

A long strip-shaped wrapping film that covers the processed surface of the arc-shaped workpiece having a non-circular cross section and is provided with abrasive grains on one surface of the thin substrate;
A rotation driving means for rotating the workpiece;
Oscillation means for oscillating the workpiece in the axial direction;
Concave shoe means for pressing the abrasive grain surface of the wrapping film against the processing surface of the workpiece by a concave shoe provided on the back side of the wrapping film;
A lapping apparatus having
A lapping apparatus characterized in that a film holding mechanism for holding at least one side end of the wrapping film is provided in the concave shoe means.   2. The lapping apparatus according to claim 1, wherein the film holding mechanism has a concavo-convex fit between at least one side end portion of the wrapping film and a holding roller that feeds the wrapping film in the longitudinal direction. .   The lapping apparatus according to claim 2, wherein the film holding mechanism includes a plurality of holding rollers provided on the concave shoe along at least one of a feeding direction or an oscillation direction of the wrapping film.   The lapping apparatus according to claim 2 or 3, wherein the film holding mechanism includes a pressing mechanism that applies a pressing force for separating the holding rollers provided along the oscillation direction.   The lapping apparatus according to any one of claims 2 to 4, wherein the film holding mechanism includes a stopper mechanism that stops rotation of the plurality of holding rollers provided along a feeding direction of the wrapping film. .   The film holding mechanism includes a tension applying mechanism that applies tension to the wrapping film by rotating the holding rollers provided along the feeding direction of the wrapping film in opposite directions before processing the workpiece. The lapping apparatus as described in any one of 2-5.   The wrapping according to any one of claims 2 to 6, wherein the film holding mechanism has protrusions formed at equal intervals on an outer periphery of the holding roller fitted in a recess formed in the wrapping film. Processing equipment. It is arranged so as to cover the work surface of the arc-shaped work with a non-circular cross section, and while rotating the work and oscillating in the axial direction while pressing the abrasive grain surface against the work surface of the work by the concave shoe, A long belt-shaped wrapping film that wraps the processed surface of the workpiece,
A wrapping film characterized in that an uneven fitting portion for engaging with an outer periphery of a holding roller provided in the vicinity of the concave shoe is provided at at least one side end.

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