JP2005349526A - Lapping machining device and lapping machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lapping machining device and a lapping machining method, capable of preventing unevenness in machining due to wear, peeling, or deviation of abrasive grains of a lapping film, having a long life of a recessed shoe and the lapping film, and keeping evenness in machining for a long term, even when lapping machining is carried out by using the recessed shoe. <P>SOLUTION: After lapping a machined surface of work W, the lapping film 11 is made to have width L which enables moving the work W in an axial direction by a predetermined amount x and lapping that with a new abrasive grain surface of the lapping film 11. Therefore, even if the abrasive grains in a part on which the maximum load is applied wear or peel off when oscillating the work W, only by moving the work in the axial direction, lapping machining can be carried out by the new abrasive grain surface of the lapping film 11. Consequently, evenness in machining can be kept for a long term. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  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.

  In particular, in a direct-acting valve system in which the valve lifter is operated directly by the camshaft, the frictional force acting between the camshaft and the valve lifter directly affects the fuel consumption, so reducing the frictional force is extremely important. However, when the vicinity of the top portion of the cam lobe portion where the most frictional force is generated has a concave shape having the small convex portion, the small convex portion comes into contact with a smooth valve lifter, and the surface pressure increases locally. There is a possibility that the frictional force increases and a smoother operation cannot be expected.

  As a result, it is preferable that the center portion of the cam lobe is a middle convex cam lobe where the load of the valve lifter is applied. In forming such a middle convex cam lobe, a wrapping film is used. Before the superfinishing process, the cam nose portion or the vicinity of the top portion may be formed into a middle convex shape, so-called crowning shape. However, this molding process is not preferable in terms of cost because it requires a separate facility for using a grindstone.

  Therefore, recently, the shape of the tip of the shoe has a concave shape in the direction of rotation of the workpiece, and an arc-shaped concave shape in the direction of the workpiece axis. May be formed into a convex shape.

  However, if an arc-shaped concave shoe is used for the workpiece axial direction, the outer edge of the wrapping film is subjected to an excessive surface pressure than the edge of the workpiece that reciprocates during oscillation, causing abrasive wear on the abrasive grains. Otherwise, the wrapping film may be partially peeled or misaligned from the work surface of the workpiece, resulting in non-uniform wrapping, a reduction in processing amount, and product quality.

In addition, the concave shoe also suffers from abrasion due to rubbing with the wrapping film and deformation due to load, so that the predetermined concave shape cannot be maintained, the surface roughness of the workpiece is deteriorated, and it is necessary to frequently replace it, This is reflected in the product, which may increase the cost of the product itself.
JP-A-7-237116 (see FIGS. 1 and 2)

  The present invention has been made in order to solve the above-described problems. Even when a lapping process is performed using a concave shoe, the process of processing caused by abrasion and peeling or misalignment of abrasive grains of a lapping film is performed. An object of the present invention is to provide a lapping apparatus and a lapping process method that can prevent non-uniformity and maintain the processing uniformity over a long period of time, in which the life of the concave shoe and the lapping film is long.

  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. A rotation driving means for rotationally driving the workpiece; an oscillation means for oscillating the workpiece in the axial direction; and a polishing grain surface of the wrapping film on the processing surface of the workpiece. A lapping processing device having a concave shoe to be pressed, wherein the width of the lapping film is lapped on the processed surface of the workpiece, and then the workpiece is moved by a predetermined amount in the axial direction to obtain new abrasive grains of the lapping film The width is such that lapping can be performed on the surface.

  In the lapping method according to the present invention for achieving the above object, a work surface of a work having an arc shape with a non-circular cross section is covered with a long belt-like lapping film in which abrasive grains are provided on one surface of a thin substrate. The lapping film is a lapping method for lapping the work surface of the work by pressing the lapping film from the back side with a shoe to drive the rotation of the work and oscillate in the axial direction. Once lapping is performed, the workpiece is moved by a predetermined amount in the axial direction, and lapping is performed on a new abrasive surface of the lapping film.

  In the apparatus of the present invention configured as described above, the width of the wrapping film can be lapped on the abrasive surface of a new wrapping film after the work surface of the work is lapped and then moved by a predetermined amount in the axial direction. Even if the abrasive grains in the most loaded part wear and peel when the work is oscillated, if the work is moved in the axial direction, lapping is performed on the abrasive surface of the new lapping film. As a result, it is possible to prevent non-uniformity of processing due to abrasion and peeling or misalignment of the abrasive grains of the wrapping film, and to maintain good processing over a long period of time and improve product quality.

  In the method of the present invention configured as described above, once the work surface of the work is lapped, the work is moved by a predetermined amount in the axial direction and lapped with a new abrasive surface of the lapping film. This prevents wear and peeling of abrasive grains and non-uniform processing due to misalignment, keeps the wrapping film and shoes in good condition for a long time, and as a result maintains uniform processing and improves product quality. Can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
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 outlined. A wrapping film 11 in which abrasive grains are provided on one surface of a non-stretchable and deformable thin base material, and disposed on the back side of the wrapping film 11. The tip 3 has a concave shape in the rotational direction of the workpiece W (hereinafter referred to as the concave shoe 3) and the abrasive grain surface of the wrapping film 11 can be pressed against the workpiece W and can be swung at least in the rotational direction of the workpiece W. Oscillation along the axial direction of the workpiece W is applied to at least one of the workpiece support W and the wrapping film 11, the shoe support device 2 that supports the concave shoe 3, the rotational drive device 40 that rotationally drives the workpiece W. The wrapping film 11, the concave shoe 3, and the shoe support means 2 are workpieces W. A plurality of cam lobes 61 provided in the axial direction of the camshaft 60 are 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 forming 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 portion is constant at the base portion d, but is very large because the event portions b ₁ and b ₂ are substantially linear, and the top portion a is relatively small. For this reason, in the cam lobe part 61, since the frictional force is generated most at the top part a, the top part a may be essentially a crowning shape.

  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 sewing machine 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.

Speed Vo of the oscillation is desired speed by changing the rotational speed of the oscillation motor M ₂ (e.g., 10 Hz) is set to, amplitude of the eccentric rotor 51 relative to the axis of oscillation motor M ₂ It is set based on the amount of eccentricity. 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.

  Although the wrapping film 11 has various types, in this embodiment, the thin base material 11a (see FIG. 6) is made of a highly non-stretchable material, 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, etc.) having a particle diameter of about several μm to 200 μm are uniformly attached to the inner surface of the base material by an adhesive. .

  On the other surface of the thin base material 11a, a resistance material (not shown) such as rubber or synthetic resin is back-coated or anti-slip processing is performed in order to prevent the concave shoe 3 from slipping.

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 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.

The winding roller 16 is connected the winding motor M _3, when rotating the take-up roller 16 by actuating the take-up motor M3, the wrapping film 11 is sequentially unwound 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. Incidentally, the tension of the wrapping film 11 is given by the operation of the locking device (not shown) and a take-up motor M ₃ provided in the vicinity of the feed roller 15 and the take-up roller 16.

  The upper arm 22 and the lower arm 23 forming a pair are relatively openable and closable in the Z direction with the support pin 24 as a center, and a fluid pressure cylinder operated by hydraulic pressure or pneumatic pressure is provided 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.

  5 is a schematic view of the shoe portion of the first embodiment of the present invention, FIG. 6 is a schematic cross-sectional view taken along line 6-6 of FIG. 5, FIG. 7 is an enlarged view of the roller portion of FIG. 7 is a schematic sectional view taken along line 8-8, FIG. 9 is a side view showing the guide roller portion of FIG. 5, and FIG. 10 is a schematic sectional view taken along line 10-10 of FIG. In FIG. 5, the concave shoe 3 and the wrapping film 11 are shown separated from each other for ease of understanding.

  In particular, in the present embodiment, the width L of the wrapping film 11 is large so that the work surface of the workpiece W is lapped and then the workpiece W is moved a predetermined amount in the axial direction and lapped with a new abrasive surface. Along with this, a pair of concave shoes 3 are also arranged spaced apart by a predetermined length in the axial direction of the workpiece W.

  Further details will be described. First, as shown in FIGS. 2 and 3, the concave shoe 3 is provided at the upper part and the lower part centering on the workpiece W, but in this embodiment, as shown in FIGS. 5 and 6, A pair is also arranged in the axial direction of the workpiece W so as to be separated by a predetermined length. The upper pair of concave shoes 3 and the lower pair of concave shoes 3 are respectively supported by shoe support means 2.

  The position where the upper or lower pair of concave shoes 3 are installed apart from each other in the axial direction of the workpiece W is the position where the workpiece W is first lapped and the workpiece W is moved in the axial direction. This is the position to wrap.

  The shoe support means 2 has a shoe case 28 that can be moved up and down by a spring 33 in a recess 27 provided at the tip of the arms 22 and 23, and a pair of shoes spaced apart in the axial direction within the shoe case 28. The concave shoe 3 is supported so as to be swingable about the swing pin 29 in the direction in which the workpiece W rotates. 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.

  The concave shoe 3 is made of, for example, metal, ceramic, hard urethane resin, or the like, but the side in contact with the workpiece W, that is, the shape of the tip portion 3d is as shown in FIG. In the axial direction of the workpiece W, as shown in FIG.

  Of the shapes of the concave shoe tip 3d, the shape of the workpiece W in the rotational direction is such that the concave portion 3b is formed at the center, and the center line passing through the swing pin 29 is symmetrical with respect to the concave portion 3b. As shown in FIG. 2, a circular arc surface 3a having a symmetrical 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 this 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”.

  The shape of each concave shoe front end portion 3d in the workpiece axial direction is such that the work surface of the workpiece W is formed in a middle convex shape following the shape of the concave shoe front end portion 3d. It has a shape.

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 width L of the wrapping film 11 may be any width that allows the workpiece W to be moved by a predetermined amount in the axial direction after lapping the work surface of the work W and lapping with a new abrasive surface. Specifically, as shown in FIG. 6, the processing surface width w ₁ of the workpiece W, the oscillation width w ₀ (about 2 mm), and the allowance δ (which differs depending on the workpiece W to be processed, generally 3 mm). And the amount of movement x in the axial direction of the workpiece.

  Here, the movement amount x of the workpiece in the axial direction is not limited to the influence of the abrasion of the first processed abrasive grain surface and the peeled abrasive grains, and is not unnecessarily large. According to this, it has been found that about 6 mm is sufficient.

Accordingly, the width L 0 of the wrapping film 11 when wrapping the processing surface of one workpiece W at two locations with an oscillation width w ₀ of 2 mm, a margin δ of 3 mm, and an axial movement amount x of the workpiece 6 mm. If we calculate
3 mm + 2 mm + working surface width w ₁ +6 mm + 2 mm + working surface width w ₁ +3 mm = 2w ₁ +16 mm.

  Here, as the moving mechanism 55 for moving the workpiece W in the axial direction, as long as the tables 47 and 48 are simultaneously moved in the same direction in the X direction, a mechanism that reciprocates by hydraulic pressure or a mechanism that rotates eccentrically by a motor. However, in this embodiment, as shown in FIG. 1, it is configured by the same as the oscillation means 50.

  In order to move the workpiece W in the axial direction, a table 47 on which a head stock 42 that supports one end of the cam shaft 60 is placed, and a tail stock 46 that has a center 45 that supports the other end of the cam shaft 60 are placed. Since it is necessary to simultaneously move the table 48 in the X direction, a means for moving left and right in the X direction similar to the oscillation means 50 is provided between the tables 47 and 48.

  The wide wrapping film 11 is less likely to be misaligned during oscillation, but it is not always possible to completely prevent misalignment in any state.

For this reason, in this embodiment, as shown in FIGS. 5 and 7 to 10, the positional deviation prevention means F that regulates the positional deviation of the wrapping film 11 in the width direction is provided with guide rollers R ₁ , R ₂ , R ₃ , It is provided on R ₄ or a feed roller R (R _{1 to} R ₄ or generic name of 15, 16) such as a supply roller 15 and a take-up roller 16.

  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 machining surface is formed into a middle convex shape in the workpiece axis direction, machining the workpiece W with both end portions of the cam lobe portion 61 having an edge portion of approximately 90 degrees while machining is completed. Thus, the edge portion hits the wrapping film 11 and the abrasive grains 4 are peeled off or dropped off, and the wrapping film 11 may be displaced due to a large force acting in the axial direction. When misalignment occurs, the number of the working abrasive grains decreases, the processing amount decreases, and the processing becomes uneven.

Therefore, in the present embodiment, the positional deviation prevention means F is applied to the guide rollers R ₁ and R ₄ provided for supplying, guiding and winding the wrapping film 11 or the feed roller R such as the supply roller 15 and the take-up roller 16. Is provided.

  The misalignment prevention means F has a different configuration depending on the state where the feed roller R and the wrapping film 11 are in contact with each other.

For example, among the feed rollers R, guide rollers R ₁ , R ₄ or supply rollers 15 and take-up rollers 16 that are used at a portion where the wrapping film 11 is in contact with about 90 degrees are shown in FIGS. As shown, a U-shaped guide member 71 having a flat cross section that covers the feed roller R by about 90 degrees with a small clearance so as not to contact the feed roller R is used.

Further, the guide roller as R _2, when wrapping the film 11 is in contact about 180 degrees, as shown in FIGS. 9 and 10, sectional flattened U-shaped guide member which covers the feed roller R about 180 degrees 72 is used.

Such a guide member 71 or 72 is preferably provided on all the rollers from the supply roller 15 to the take-up roller 16, but may be disposed only on the guide rollers R ₁ , R ₂ , R ₄ , in some cases it may also be provided on the guide roller R _3.

  Next, the operation of this embodiment will be described.

Initially, both pressure arm 22, 23 is in the open each state corresponding to each cam lobe portion 61, when operating the take-up motor M _3, the wrapping film 1 by rotating the winding roller 16 is provided on the feed roller R Guided by the guide member 71 or 72 and moved by a predetermined amount without causing a positional shift, a lapping film 11 having a new abrasive grain surface is set on the concave shoe 3 portion.

Lock the locking device provided near the supply roller 15, when operating the take-up motor M _3, the wrapping film 1 is applied a predetermined tension, since the taut, take-up roller in this state Lock the lock device in the vicinity of 16.

  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 activating the oscillation motor M _2, eccentric rotor 51 rotates 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 in this way, the concave shoe 3 pressed against the workpiece W moves the swing pin 29 while moving forward and backward along the cam lobe portion 61 having a non-circular arcuate circumferential surface. Lapping is performed on the abrasive surface of the wrapping film 11 while swinging to the center. The camshaft 60 has a large number of cam lobes 61, which are lapped together.

  On the other hand, when the workpiece W is oscillated in the axial direction, 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 workpiece machining efficiency is reduced. Can be increased.

  In this embodiment, since the positional deviation prevention means F is provided in the feed roller R, the wrapping film 11 does not cause positional deviation even when oscillated. Therefore, uniform lapping can be performed without reducing the number of working abrasive grains and the amount of processing.

When the predetermined lapping process, for example, the process performed by rotating the workpiece W forward is completed in this way, the motors M ₁ and M ₂ are stopped, and the rotation of the workpiece W is also stopped. In this state, when both the pressing arms 22 and 23 are once opened and the moving mechanism 55 is operated, the workpiece W moves by a predetermined amount x in the axial direction, and the cam lobe portion 61 of each workpiece has a width L of the wrapping film 11. Move to a different position within. The width L of the wrapping film 11 of this embodiment is large, and this other position is a new abrasive grain surface that has not been lapped.

When the pressing arms 22 and 23 are closed again after the workpiece W moves in the axial direction, the concave shoe 3 adjacent to the initially used concave shoe 3 pushes the wrapping film 11 against the work surface of the workpiece W. wear. Reversely rotating the motor M _1, when actuating the oscillation motor M _2, the workpiece W is oscillation while reversed and lapping a new abrasive surface.

  Since the concave shoe 3 has an arc shape in the workpiece axial direction, the edge portion of the workpiece that reciprocates by oscillation during forward rotation or reverse rotation is large on the tip 3d of the concave shoe 3 or the wrapping film 11. A load is applied, and the wrapping film 11 causes abrasion and peeling of the abrasive grains, and the concave shoe 3 causes wear and deformation with the wrapping film 11.

  However, in this embodiment, since the position of the workpiece W and the wrapping film 11 is different between the forward rotation and the reverse rotation, and the concave shoe 3 is also different, the workpiece W is an abrasive grain portion that has been worn and peeled off by the previous processing. Then, the processing is performed without using the concave shoe 3, and the abrasion and separation of the abrasive grains in the previous processing and the deformation of the concave shoe 3 do not adversely affect the subsequent processing.

Therefore, the lapping process of the present embodiment can form the workpiece W in a middle convex shape following the middle concave shape of the wrapping film 11 while maintaining the processing uniformity over a long period of time.
<Second Embodiment>
In the embodiment described above, the misalignment prevention means F is provided on the feed roller R, but as shown in FIGS. 13 and 14, it can also be provided on the shoe portion. FIG. 11 is an enlarged front view showing the shoe portion of the second embodiment of the present invention, and FIG. 12 is a schematic sectional view taken along line 12-12 of FIG.

The displacement prevention means F of this embodiment, the bottom of the concave portions 3b formed in a deep groove shape in the central portion of the concave shoe 3, set up a tension roller R _t with axis parallel to the axis of the workpiece W, the concave the shoe 3, is provided with a guide member 73 to prevent misalignment of the wrapping film 11 wound around the tension roller R _t.

Since the cause of the positional deviation of the wrapping film 11 is the force received by the wrapping film 11 during oscillation, the positional deviation prevention means F is located at a portion where the wrapping film 11 receives a force due to the oscillation, that is, a position close to the processing position. Since the wrapping film 11 is preferably provided with a tension in a portion that is essentially close to the processing position, in this embodiment, a tension roller _Rt is provided on the concave shoe 3 to provide a wrapping film. The position shift is regulated by the guide member 73 as shown in FIG. 9 and FIG.

  The concave shoe 3 of the first embodiment described above has the arcuate surface 3a having a convex cross section, but the arcuate surface 3a of the present embodiment is formed in a substantially semicircular shape so that the wrapping film 11 smoothly becomes the shoe. It is possible to move along.

The guide member 73, in order to prevent misalignment of the wrapping film 11 wound with a tension roller R _t, are opposed with a gap of small allowed so as not to be in contact with the tension roller R _t provided at the bottom of the concave portion 3b, A plate-like member having a U-shaped groove that covers the tension roller _Rt by about 180 degrees is provided on the side surface of the concave shoe 3.

Further, in this embodiment, it is also provided tensioning means T for applying tension to the lapping film 11 by using the tension roller R _t. Tensioning means T has one end to the rotary shaft 75 of the tension roller R _t is engaged, is constituted by a spring member 76 and the other end is engaged with the pivot shaft 29.

Outward tension roller R _t by the elastic force of the spring member 75, that is biased towards the bottom of the deep groove-shaped concave portion 3b, and traction while in close contact with lapping film 11 to the arcuate surface 3a of the concave shoe 3, a predetermined Of tension.

  In this way, when the misalignment prevention means F and the tension applying means T are provided on the concave shoe 3 which is the position closest to the part where the workpiece W is processed, even when the wide wrapping film 11 is provided, it is tightly stretched. Since the positional displacement can be reliably prevented, the wrapping film 11 is not loosened or peeled off, and the concave shoe 3 and the wrapping film 11 function smoothly and have a long life. Further, the lapping process can maintain the uniformity over a long period of time.

  As described above, according to each embodiment of the present invention, after the lapping film 11 is lapped on the processed surface of the workpiece W, the workpiece W is moved by a predetermined amount in the axial direction, and a new lapping film 11 is ground. Since the width L is such that lapping can be performed on the grain surface, even if the abrasive grains in the most loaded portion are worn and separated when the workpiece W is oscillated, if the workpiece is moved in the axial direction, a new one can be obtained. The lapping film 11 can be lapped on the abrasive grain surface, reducing abrasive wear and peeling, extending the life of the concave shoe and wrapping film, achieving long-term processing uniformity, and providing a good workpiece surface Can be formed into a middle convex shape.

If the width of the wrapping film 11 is determined on the basis of the processed surface width w ₁ of the workpiece W, the oscillation width w _0, and the axial movement amount x of the workpiece W, the unnecessarily wide wrapping film 11 is formed. Even without using, it is possible to stably form the processing surface of the workpiece having an intermediate convex shape.

  If the concave shoe 3 is provided at a position where the workpiece W is first lapped and a position where the workpiece W is moved in the axial direction and lapped, even if a load is applied when the workpiece W is oscillated, An extreme adverse effect can be avoided, the life of the concave shoe 3 can be extended, the uniformity of processing over a long period of time can be achieved, and the workpiece processed surface can be formed into a good middle convex shape.

  If both side ends of the wrapping film 11 are restricted by the position shift prevention means F for preventing the position shift in the width direction during oscillation, the wrapping film 11 will not be displaced even during the oscillation. Uniform processing can be performed without causing a reduction in the number of abrasive grains and a decrease in the processing amount, and the processing surface of the intermediate convex workpiece can be stably formed.

  If the misalignment prevention means F is provided on the feed roller R for supplying, guiding and winding the wrapping film 11, it will not be twisted even if the wrapping film 11 is fed, and the misalignment at the time of processing will also be reduced. Can be prevented.

  If tension is applied to the wrapping film 11 in the axial direction by a tension applying means provided in the vicinity of the workpiece processing position, the wrapping film 11 can be more reliably prevented from being displaced, and the wrapping film itself is not easily broken. Following the shape of the film 11, the work surface of the workpiece can be easily formed, and a good middle convex shape can be finished. Moreover, even the wide wrapping film 11 can hold a tightly stretched film while preventing misalignment, making the concave shoe 3 and the wrapping film 11 have a long life, which is advantageous in terms of cost, Uniformity can be maintained over a long period of time.

The tensioning means T, the recess 3b of the concave shoe 3, provided with a tension roller R _t having an axis 75 axis parallel to the workpiece W, the tension roller R _t the wrapping film 11 resilient means 76 in a direction perpendicular to the plane of the By energizing with, even the wide wrapping film 11 can be tightly stretched at the processing position, the processing uniformity can be maintained over a long period of time, and the workpiece processing surface can be formed into a good middle convex shape.

  When the tension applying means T has the positional deviation preventing means F, even the wide wrapping film 11 can hold the tensioned state while preventing the positional deviation, and the concave shoe 3 and the wrapping film 11 can be held. Long service life and uniform processing can be maintained over a long period of time. In addition, the work surface can be formed into a good middle convex shape.

  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 of the concave shoe 3 has an arcuate concave shape in the axial direction of the workpiece in order to form the machining surface from the fact that the workpiece W is the cam lobe portion of the camshaft into an intermediate convex shape. However, the present invention is not limited to this, and the tip of the concave shoe 3 may be flat in the axial direction depending on the workpiece W.

  INDUSTRIAL APPLICABILITY The present invention is suitable for lapping processing in which a cam lobe portion of a cam shaft used for an automobile engine is formed in a middle convex shape.

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 of 1st Embodiment of this invention. FIG. 6 is a schematic cross-sectional equivalent view taken along line 6-6 in FIG. 5. It is an enlarged view of the roller part of FIG. It is a schematic sectional drawing which follows the 8-8 line of FIG. It is a side view which shows the guide roller part of FIG. It is a schematic sectional drawing which follows the 10-10 line of FIG. It is an enlarged front view of the shoe part of 2nd Embodiment. It is a schematic sectional drawing in alignment with line 12-12 of 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,
76 ... elastic means,
F: Misalignment prevention means,
L ... The width of the wrapping film,
R ... feed roller,
R _t ... tension roller,
T: Tension applying means,
W ... work _{w 0} ... oscillation of width,
w ₁ ... the width of the workpiece surface,
x: Axial movement of workpiece.

Claims (9)

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;
A concave shoe that is provided on the back side of the wrapping film and presses the abrasive surface of the wrapping film against the work surface of the workpiece;
A lapping apparatus having
The wrapping film has a width that allows the workpiece to be moved by a predetermined amount in the axial direction and lapped on the abrasive surface of a new wrapping film after lapping the workpiece surface. Processing equipment.   2. The lapping apparatus according to claim 1, wherein the width of the lapping film is determined based on at least a width of a machining surface of the workpiece, a width of oscillation, and an axial movement amount of the workpiece.   3. The lapping apparatus according to claim 1, wherein the concave shoe is provided at a position where the workpiece is first lapped and a position where the workpiece is moved in the axial direction and lapped. 4.   The lapping film processing apparatus according to any one of claims 1 to 3, wherein both ends of the lapping film are regulated by a misalignment preventing unit that prevents misalignment in the width direction during the oscillation.   5. The lapping apparatus according to claim 4, wherein the displacement prevention means is provided on a feed roller for supplying, guiding and winding the wrapping film.   The lapping apparatus according to any one of claims 1 to 5, wherein the wrapping film is applied with a tension in an axial direction by a tension applying means provided near a position where the workpiece is processed.   The tension applying means is provided with a tension roller having an axis parallel to the axis of the workpiece in the concave portion of the concave shoe, and the tension roller is urged by an elastic means in a direction perpendicular to the surface of the wrapping film. The lapping apparatus according to claim 6, wherein the lapping apparatus is characterized.   The lapping apparatus according to claim 6 or 7, wherein the tension applying unit includes a position shift prevention unit that restricts a position shift in a width direction of the wrapping film on the concave shoe.   Cover the work surface of the arc-shaped workpiece having a non-circular cross section with a long belt-shaped wrapping film in which abrasive grains are provided on one surface of the thin substrate, and press the wrapping film with a shoe from the back side, A lapping process method for lapping a work surface of the work by rotating the work and oscillating in the axial direction, wherein the work surface of the work is lapped once, and then the work is given a predetermined amount in the axial direction. A lapping method comprising moving and lapping on a new abrasive surface of the lapping film.

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