JP2924890B2 - Polishing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polishing a workpiece with a polishing tape.

[0002]

2. Description of the Related Art The following is already known as one type of polishing apparatus for performing the above-mentioned polishing method. In this method, the polishing tape is pressed against the work surface of the workpiece at a predetermined polishing position, and the polishing tape and the workpiece are moved relative to each other to polish the workpiece, and the polishing tape is fed in the longitudinal direction thereof. As used herein, the term "abrasive tape" refers to a belt-like material in which an abrasive (eg, abrasive grains) is adhered to a surface of a flat base material made of cloth, paper, a synthetic resin sheet, or the like.
When sending the "polishing tape", at least one of before, after and during each polishing can be selected.

A conventional example of this type of polishing apparatus will be described with reference to FIG. First, in brief, in this polishing apparatus, an outer peripheral surface of a cylindrical work W is a processing surface, and two positions opposed to each other across the work W are set as scheduled polishing positions. And this polishing equipment,
While simultaneously pressing one polishing tape T to two predetermined polishing positions on the work W, the work W is rotated about its axis to relatively move the work W and the polishing tape T,
Thereby, the work W is polished. Further, in this polishing apparatus, the polishing tape T is kept stationary during polishing, but every time one polishing is completed, the polishing tape T is fed by a certain amount in the longitudinal direction prior to the next polishing, and the polishing tape T is polished. The portion of the tape T pressed to each of the predetermined polishing positions is sequentially updated.

More specifically, in this polishing apparatus, as shown in FIG. 1, a pair of shoes 400 opposed to each other across a work W is a pair of shoes 400 rotatable around a rotation shaft 401. By being attached to one end of the clamp arm 402, the air cylinder 403 attached to the other end of the pair of clamp arms 402 can approach and separate from each other.

The positions facing the respective shoes 400 on the outer peripheral surface of the work W are the respective predetermined polishing positions. In this polishing apparatus, the polishing tape T moves from the entrance side (the right side in the figure) to the exit side (the left side in the figure). It progresses toward and passes the shoe 400 on the way. Specifically, on the entrance side, an unused polishing tape T is wound around a tape supply reel 404 rotatably mounted on the main body of the polishing apparatus, and the polishing tape T emerging therefrom is guided by several guide rollers 406. The used polishing tape T is guided and proceeds to the outlet side via the pair of shoes 400 so that the used polishing tape T reaches the used polishing tape storage box 408 provided on the outlet side.

[0006] The path of the polishing tape T near the shoe 400 will be described in detail.
Due to 6, the pair of clamp arms 402 pass through the outside of the one located on the entrance side and reach the shoe 400 fixed to the entrance-side clamp arm 402. afterwards,
Instead of immediately going to the shoe 400 fixed to the other clamp arm 402, a pair of clamp arms 40
The second shoe 400 is directed to the other shoe 400 via a guide roller 406 disposed in the middle of the second shoe 400. That is, the polishing tape T simultaneously contacts the outer peripheral surface of the work W at two locations, but there is a non-contact portion that does not contact the work W between the two portions of the polishing tape T that contact the work W.

[0007]

As is apparent from the above description, the above-described conventional polishing apparatus uses two polishing tapes to form two or more pieces on the same processing surface of a work. The parts are polished simultaneously. On the other hand, an object of the present invention is to make it possible to simultaneously perform a plurality of types of polishing with different conditions on the same machined surface of a workpiece. The object is achieved by the following aspects of the present invention. In the following description, each aspect of the present invention will be described in the same form as the claims, with the respective items numbered. This is to clarify the possibility of adopting a combination of the features described in each section, excluding the possibility of adopting a combination other than the combinations described here, or excluding the features described here. It does not exclude the possibility of combining the features. (1) A method of polishing a work with a polishing tape,
The polishing tape is made of two polishing tapes having different surface roughnesses to which abrasive grains are adhered, and the two polishing tapes are placed on a cylindrical processing surface of a work by two opposing surfaces across the work. A polishing method characterized in that a work is rotated about its axis while simultaneously pressing each at a predetermined polishing position (claim 1). According to this method, it is possible to simultaneously perform two types of polishing with different conditions on the same cylindrical processed surface of the work, thereby improving the polishing efficiency. Further, according to this method, the force acting on the work from the polishing tape during polishing on one of the two sides sandwiching the work and the force acting on the work from the polishing tape on the other side are opposite to each other on the same straight line, Cancel each other out. Therefore, it is not essential to take measures to prevent the work from being bent during polishing. (2) The polishing method according to item (1), wherein the workpiece is reciprocated in the direction of its rotation axis simultaneously with the rotation. In this method, during polishing, the workpiece is rotated about its axis and simultaneously reciprocated in its axial direction. (3) The two polishing tapes are held by a polishing tape holding unit that holds the two polishing tapes via a pair of cartridges that are detachable from the polishing tape holding unit (1) or The polishing method according to item (2) [Claim 3].
In this method, the polishing tape is held in a cartridge that can be separated from the polishing tape holder. Therefore, the operator can attach / detach the polishing tape via the cartridge. On the other hand, the attaching / detaching operation of the cartridge is simpler than the conventional attaching / detaching operation directly touching the abrasive tape. Therefore, according to this method, the operation of replacing the polishing tape is simplified as compared with the conventional polishing method in which the polishing tape is directly held by the polishing tape holding portion. (4) each of the pair of cartridges, (a) a tape supply unit capable of storing each of the two polishing tapes and supplying them to the outside of the cartridge, and (b) the tape of each polishing tape A pressing member that presses a part supplied to the outside of the cartridge by the supply part against the processing surface, and (c) a tape storage part capable of storing a part of each polishing tape that has entered inside from the outside of the cartridge ( Polishing method described in 3). (5) The polishing method according to (3) or (4), wherein each of the cartridges is a one-time type in which the same portion in the longitudinal direction of each of the polishing tapes is not used again for polishing. (6) the respective cartridges hold the respective polishing tapes so as to be able to circulate between the tape supply unit and the tape storage unit,
The polishing method according to item (4), wherein the same portion in the longitudinal direction of the polishing tape is a reusable type used again for polishing. When this method is adopted, it is desirable to provide a dresser for reusing the polishing tape in the cartridge. (7) In each of the cartridges, the tape supply unit is a tape supply reel, the tape storage unit is a tape take-up reel, and one polishing tape is wound around the tape supply reel and the tape take-up reel. The polishing method according to the above mode (4) or (6), wherein the polishing method is a reel type capable of holding the surface. (8) The polishing method according to (7), wherein when the polishing tape wound around the tape supply reel is unwound from the tape supply reel by the tape take-up reel, a rotation resistance is added to the tape supply reel. According to this method, when the polishing tape wound on the tape supply reel is unwound by the tape take-up reel, or when the polishing tape is pulled as the workpiece is rotated during polishing, the polishing tape becomes loose. Does not occur. (9) the tape take-up reel is attached to a housing of the cartridge via a one-way clutch,
Accordingly, the tape winding reel is allowed to rotate in the direction in which the polishing tape is wound, but is prevented from rotating in the direction in which the polishing tape is unwound. According to this method, the polishing tape does not have to be pulled out from the tape take-up reel during polishing, and the portion of the polishing tape between the tape take-up reel and the work does not need to be loosened. (10) a frame, a clamp unit connected to the frame, which has a pair of clamps for moving the pair of clamps closer to and away from each other, and each of the pair of clamps is provided with abrasive grains. A pair of polishing tape holding portions capable of holding each of two polishing tapes having different surface roughnesses adhered to each other independently, and each of the polishing tapes held by each polishing tape holding portion in a longitudinal direction thereof. A polishing tape feeder, a work holding device for rotatably holding a work to be polished around its axis, and a work rotating device for rotating the work held by the work holding device around its axis. Including polishing system. Here, the polishing tape feeding device includes, for example, a motor as a drive source, a controller for electrically controlling the motor, and the like. (11) The work holding device holds the work so as to be rotatable about its axis and reciprocally movable in the axial direction, and the polishing system further includes a work held by the work holding device. The polishing system according to item (10), further comprising a work reciprocating device for reciprocating the workpiece along its axis. (12) The clamp unit is connected to the frame so as to be relatively movable in a plane intersecting the rotation axis of the work held by the work holding device, and a portion of the work to be polished during polishing is When revolving, the pair of polishing tape holders are moved following the revolution.
A polishing system according to (10) or (11). (13) The polishing system according to any one of (10) to (12), wherein the pair of clamps are moved toward and away from each other by being moved in parallel with each other. (14) The polishing system according to any one of (10) to (13), further including a pair of cartridges detachably held by the pair of polishing tape holding portions and holding the two polishing tapes, respectively. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a more specific embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a polishing system suitable for performing a polishing method according to an embodiment of the present invention. This polishing system rotates a workpiece having an axis around its axis,
Polishing is performed by pressing the polishing tape T held in a fixed position against the work, and a predetermined amount of the polishing tape T is fed each time polishing is completed, and each polishing is performed by a new portion of the polishing tape T. Do with. Further, this polishing system uses two polishing tapes T ₁ , T ₂ in a circle of the work 10.
By rotating the work 10 around its axis while simultaneously pressing at two scheduled polishing positions facing each other with the work 10 separated on the cylindrical processing surface,
Independent polishing is performed for each scheduled polishing position.

This polishing is an example of a super-finishing process performed to secure the surface roughness of a processing surface of the work 10 (a journal surface and a pin surface of the crankshaft 10 described later). This is a paper wrapping process performed by polishing tapes T ₁ and T ₂ , which are papers with abrasive grains. The two polishing tapes T ₁ and T ₂ have different abrasive grain sizes, densities, and the like between them. As a result, the roughness of the surface to which the abrasive grains are bonded is different from each other. ing.

The work to be polished by this polishing system is a crankshaft which is an example of a work having a plurality of outer peripheral surfaces formed side by side. Crankshaft 10
As is well known, is a part used in a vehicle engine, and as shown in FIG. 2, a journal part 12 supported by a cylinder block (not shown) and a pin part connected by a piston and a connecting rod. 14 are alternately arranged. The journal portion 12 is arranged coaxially with the rotation axis of the crankshaft 10, while the pin portion 14 is arranged offset from the rotation axis of the crankshaft 10, so that the reciprocating motion of the piston causes the reciprocation of the crankshaft 10. Converted to rotational movement. The journal portion 12 and the pin portion 14 which are adjacent to each other on the crankshaft 10 are joined by an arm 16 extending in the radial direction, and a balance is provided at one end of the arm 16 on the opposite side to the connection side with the pin portion 14. A weight 18 is formed. Also, the crankshaft 10
Is formed with an output flange 19 at one end thereof.

The polishing system includes an outer peripheral surface (hereinafter also referred to as a “journal surface”) of each journal portion 12 and each pin portion 14.
And the outer peripheral surface (hereinafter, also referred to as a “pin surface”) of each is polished. Specifically, a process of simultaneously polishing a plurality of journal surfaces formed on one crankshaft 10 and a process of simultaneously polishing a plurality of pin surfaces formed on one crankshaft 10 Is performed on one crankshaft 10 in combination with the step of performing the polishing.

As shown in FIG. 1, the polishing system includes a frame 20, a clamp unit 22, a pair of polishing tape holding portions 24, a work holding device 26, a work rotating device 28, and a vibration device 30. As described above, since the polishing system simultaneously performs polishing on a plurality of journal surfaces and a plurality of pin surfaces simultaneously,
Although the same number of polishing units U as movable parts each comprising a clamp unit 22 and a pair of polishing tape holding parts 24 are provided as many as the number of journal surfaces or pin surfaces, only one polishing unit U is shown in the figure. Is shown in

The work holding device 26 has a table 31a having a horizontal surface. In the table 31a,
Two engaging portions 31b facing each other (including the center and the like)
The engaging portions 31b are engaged with both ends of the crankshaft 10 so that the crankshaft 10
To be rotatable about its axis. However, as shown in FIG. 3 which is a side view, the table 31a is supported by a frame 20 as a fixing member via a rail 31c, and is movable in the axial direction of the crankshaft 10.

The work holding device 26 includes a drive shaft 31 having a drive pin 31d fixed at an eccentric position.
e. The drive pin 31d fits in a hole 31f (see FIG. 2) formed beforehand at a position off the axis of the output flange 19 of the crankshaft 10 held by the two engaging portions 31b, and drives the drive shaft 31d. The shaft 31e is rotated integrally with the crankshaft 10. The drive shaft 31e is supported by the work holding device 26 so as to be able to approach and separate from the mating engaging portion 31b, and the approach and separation are performed by an air cylinder 31g as a drive source.

Further, the work holding device 26 also has a positioning mechanism for positioning the rotational direction position of the crankshaft 10 held by the work holding device 26 at a specific position. The positioning mechanism is, as shown in FIG. 4 which is a front view, (a) a rotating body 31h which rotates together with the drive shaft 31e (see FIG. 3 for the mounting position), and has a notch 31i at a specific circumferential position. (B) an air cylinder 31j as a drive source, and (c) an air cylinder 3
1j includes an engaging portion 31k that approaches and separates from the rotating body 31h.

The engaging portion 31k is displaced by the air cylinder 31j and is always retracted from the rotating body 31h. However, the engaging portion 31k is
0 is required to be positioned at a specific rotational direction position, and is pressed against the outer peripheral surface of the rotating body 31h by the air cylinder 31j to make sliding contact. When the rotational direction position of the crankshaft 10 becomes a specific position, a notch is formed. The rotator 31h is fitted into the portion 31i to lock the rotator 31h at that position. The grinding of the crankshaft 10 is completed, and after that, the proximity switch 31m detects the dog 31n rotating with the rotating body 31h for the first time, and then the rotating body 31h is decelerated by a motor described later. The cylinder 31j causes the engaging portion 31k to approach the rotating body 31h. Therefore, a situation in which the engaging portion 31k cannot be fitted into the notch 31i because the rotation speed of the rotating body 31h is too high occurs.
However, the occurrence of mechanical damage due to strong contact with the notch 31i is also reliably avoided.

On the other hand, as shown in FIG. 3, the work rotating device 28 gives a drive shaft 31e a rotational motion about an axis by a motor 28a as a drive source. Although the work rotating device 28 is fixed to the frame 20, the rotating shaft of the motor 28a is spline-fitted to the drive shaft 31e, and is connected so as to be slidable in the axial direction and relatively non-rotatable. A state of moving in a horizontal plane is secured.

The vibration device 30 shown in FIG. 1 applies an axial vibration to the table 31a and the crankshaft 10 held by the work holding device 26 in the axial direction during polishing. On the other hand, in the crankshaft 10, as shown in FIG. 2, each of the journal portions 12 and each of the pin portions 14 are each formed with a cylindrical surface that comes into contact with a mating component at a central position in the axial direction. A groove (or a corner R) is formed. Therefore, the lengths D and D 'of the cylindrical surface to be polished by the polishing tape T are shorter than the lengths C and C' of the respective journal portions 12 or the respective pin portions 14. In the present embodiment, the width of the polishing tape T is set to be substantially equal to the length D, and the polishing tape T moves each journal 12 and each pin 14 in contact with the cylindrical surface to be polished. In a reciprocating motion in the axial direction. Therefore, if the vibration device 30 applies an axial vibration to the crankshaft 10 during polishing, the crankshaft 1
0 and the reciprocating motion in the axial direction are combined to form a streak of a cross-hatching pattern on each journal surface and each pin surface, whereby the surface roughness and lubricant retention of the journal surface and the pin surface are formed. The performance is improved.

As shown in FIG. 1, a portion of the frame 20 located above the work holding device 26
Is suspended, and the hanging unit 34 is attached to the clamp unit 2.
2 are installed. The clamp unit 22 selectively performs the approach and the separation of the pair of polishing tape holding portions 24 from each other. As shown in FIG. And a clamp arm 38.

If the polishing unit U grinds only the journal portion 12 of the crankshaft 10, since the journal portion 12 is arranged coaxially with the rotation axis of the crankshaft 10, the polishing unit U is vertically polished during polishing. It is not essential to be able to move in the plane. But,
The polishing unit U is the pin portion 1 of the crankshaft 10.
4 is also polished, and the pin portion 14 revolves around the rotation axis of the crankshaft 10 during polishing, so that the polishing unit U can move in a vertical plane following the revolution of the pin portion 14 during polishing. It is essential. Therefore, the clamp unit 22 is connected to the frame 20 as follows.

A pin hole 40 is formed at the upper end of the main body 36 of the clamp unit 22.
A long hole 42 extending in the vertical direction is formed in the hanging part 34 of the zero. The main body 36 is connected to the hanging portion 34 by inserting the pins 44 into both the pin holes 40 and the elongated holes 42. Thus, the main body 36 can freely rotate around the axis of the pin 44, and the pin 44 can move up and down along the elongated hole 42. Therefore, the polishing unit U is swingable in a vertical plane around the pin hole 40 that can move up and down.

A pin hole 48 is also formed at the lower end of the main body 36. This pin hole 48 is for regulating the movement of the main body 36 and positioning the main body 36 at a specific position, and is a positioning member operated by using an air cylinder 49 built in the hanging portion 34 as a driving source. The pin 50 is fitted. The pin 50 is retracted from the pin hole 48 during polishing to allow the movement of the main body 36, and when the work W is attached to and detached from the pair of polishing tape holders 24, the pin 50 is inserted into the pin hole 48. The main body 36 is positioned at a specific position by being fitted. The fitting of the pin 50 into the pin hole 48 is performed by the work holding device 2.
6 is performed in a state where the rotational direction position of the crankshaft 10 is positioned at a specific position by the positioning mechanism including the air cylinder 31j.

A pair of parallel support shafts 54 are slidably fitted in the main body 36. Those support shafts 54
Are arranged side by side. Both ends of each of the support shafts 54 are exposed from the main body 36. The base end of the left one of the pair of clamp arms 38 (hereinafter referred to as “left clamp arm”) is fixed to a portion of each support shaft 54 exposed to the left in the drawing. On the other hand, the base end of the right one of the pair of clamp arms 38 (hereinafter referred to as “right clamp arm”) slides in the axial direction of the support shaft 54 in the portion of each support shaft 54 exposed to the right in the drawing. Supported as possible. Further, each support shaft 54
A housing 56 of a clamp cylinder 58 is fixed to a distal end of a portion exposed to the right in the drawing, and a distal end of a rod 60 extending from the clamp cylinder 58 is connected to the right clamp arm 38. In this embodiment, the clamp cylinder 58 is of a hydraulically operated type.

Therefore, in this clamp unit 22, the pair of clamp arms 38 are separated from each other when the clamp cylinder 58 retracts the rod 60, and conversely, when the clamp cylinder 58 extends the rod 60. , The pair of clamp arms 38 are moved closer to each other.

The clamp unit 22 of the polishing unit U has been described above in detail. Next, the pair of polishing tape holders 24 will be described in detail. The configuration of the pair of polishing tape holding units 24 is common to each other, so only one of them will be described in detail, and the other will not be described.

As shown in FIG. 5, the polishing tape holding section 24 includes a main body 6 formed at the distal end of the clamp arm 38.
4 and a cartridge 70. Main unit 6
The cartridge storage chamber 74 is formed in the cartridge storage chamber 4, and the cartridge 70 is detachably stored in the cartridge storage chamber 74.

A notch 80 is formed at the tip of the clamp arm 38, as shown in FIG. The notch 80 is formed to be open in a direction facing the notch 80 formed in the other clamp arm 38.
Further, a notch 8 is provided at the tip of the clamp arm 38.
A pair of plate members 82 as a closing member is attached so as to close the 0 from both sides thereof (a direction perpendicular to the paper surface in the figure). The notch portion 80 and the plate member 82 form a cartridge storage chamber 74. The pair of cartridge storage chambers 74 extend in the vertical direction, and each has a bottomed space that opens in a direction facing each other. Have been. As shown in FIG. 5, the plate member 82 has a plurality of windows for externally monitoring the state of the cartridge 70 stored in the cartridge storage chamber 74. The pair of clamp arms 38 in FIG.
Among them, the left side shows the state after the plate member 82 is attached, while the right side shows the state before the plate member 82 is attached.

As shown in FIG. 6 which is a perspective view, the cartridge 70 has one polishing tape T (two polishing tapes T).
₁ and T ₂ ) are wound around and held by a pair of reels arranged in the same plane, and include a housing 90, a tape supply reel 92, a tape take-up reel 94, and a shoe 95 as a pressing member. ing. Note that the cartridge 70 on the left side in the figure is
3 shows a state in which the cutting is performed on one plane including the rotation center of the tape take-up reel 94 at the same time.

The housing 90 has a box-like shape, and its outer surface is composed of six surfaces. Of the six surfaces, one of two surfaces parallel to the rotation plane of the pair of reels 92 and 94 is provided. It is open. However, when the cartridge 70 is stored in the cartridge storage chamber 74, the one plate member 82 serves to close the open surface of the housing 90. That is, in the present embodiment, the weight of the cartridge 70 is reduced by reducing the thickness of the cartridge 70 as much as possible. Note that the housing 90 is made of aluminum in the present embodiment, which also reduces the weight of the cartridge 70.

As shown in FIG. 6, of the six surfaces of the housing 90, a surface opposite to the open surface is a bottom surface, and a partition member 98 extends from the bottom plate 96 forming the bottom surface toward the open surface. I have. The partition member 98 branches and extends in a bifurcated manner along the surface of the bottom plate 96. The partition member 98 divides the space in the housing 90 into three spaces, a tape supply reel storage room 100, a tape take-up reel storage room 102, and a lock room 104, respectively. The tape supply reel 9 is provided in the tape supply reel storage chamber 100.
2. The tape winding reel 94 is stored in the tape winding reel storage chamber 102, respectively.

The respective rotation mechanisms of the tape supply reel 92 and the tape take-up reel 94 in the cartridge 70 are configured as follows. Tape supply reel 9
2 is a sectional view of the housing 90 as shown in FIG.
Is supported by a rotating shaft 110 having a flange portion which is rotatably provided on the bottom plate 96. The tape supply reel 92 is fitted to the rotating shaft 110 so as to be slidable in the axial direction and not to rotate relatively. In the present embodiment, as a relative rotation preventing means, a pin 111 a is diametrically penetrated through the rotating shaft 110, and a groove 111 b into which the pin 112 is fitted is formed on the inner peripheral surface of the tape supply reel 92 in the axial direction. They are formed in parallel.

The tape supply reel 92 is required not to loosen the polishing tape T when the polishing tape T is unwound from the tape supply reel 92 by the rotation of the tape take-up reel 94. Therefore, a mechanism for adding a rotation resistance to the tape supply reel 92 is also provided.

The tape supply reel 92 is supported by a rotating shaft 110 via a bottomed tubular rotating member 112. The rotating member 112 is rotatable integrally with the tape supply reel 92, and the rotating member 112 is fitted on the rotating shaft 110 so as to form an annular space 115 between its bottom plate 114 and the bottom plate 96 of the housing 90. Let me do. Annular space 1
15 includes a pair of spacers 116 and a wave washer 11.
8 are provided. The wave washer 118 is a steel washer that has a generally annular plate shape, but is distorted in a wave shape along the circumferential direction so as to function as a spring. The wave washer 118 is sandwiched between a pair of spacers 116, and both the spacer 116 and the wave washer 118 are inserted through the rotating shaft 110.

Accordingly, the bottom plate 114 is engaged with the bottom plate 96 via the pair of spacers 116 and the wave washers 118, whereby the rotating member 112 and the bottom plate 96 are engaged.
And a frictional force is generated between them, and, consequently, resistance is given to the rotation of the tape supply reel 92. That is, the wave washer 118 mainly functions as a tape supply reel rotation resistance adding means.

A plurality of female threads 120 are passed through the rotating member 112 in parallel with the rotating shaft 110, and set screws 122 are screwed into each of the female threads. Each set screw 122 is engaged with the spacer 116 at the tip.
As the set screw 122 is screwed deeper, the set screw 122
The distance between the wave washer 11 and the bottom plate 96 is reduced.
8 is made thinner. As a result, wave washer 1
18, the elastic force generated in the direction perpendicular to the plane of the surface increases, the frictional force generated between the rotating member 112 and the bottom plate 96 increases, and the rotational resistance of the tape supply reel 92 increases. That is, the set screw 122 mainly functions as the tape supply reel rotation resistance adjusting means.

In the drawings, reference numeral 124 denotes a sleeve, and 125 denotes a washer. Sleeve 12
4 is provided to suppress wear of the bottom plate 96 by the rotating shaft 110, and the washer 125 reduces the frictional force between the flange portion of the rotating shaft 110 and the bottom plate 96 more than the frictional force based on the wave washer 118. It is provided for.

On the other hand, the tape take-up reel 94 is required to prevent the tape take-up reel 94 from rotating in the direction opposite to the take-up direction during polishing to prevent the polishing tape T from becoming loose. You. As will be described in detail later, a motor is engaged with the tape winding reel 94 to apply a rotational torque for winding the polishing tape T.
As shown in FIG.
And the crankshaft 10 is rotated in a direction in which a frictional force is generated between the crankshaft 10 and the polishing tape T to pull out the polishing tape T from the tape winding reel 94.

Therefore, the tape take-up reel 94 is, as shown on the left side in FIG.
The rotary shaft 130 is rotatably supported via a one-way clutch 128 as a reverse rotation preventing mechanism so as to be relatively non-rotatable and axially slidable. The one-way clutch 128 allows only rotation in the direction in which the tape winding reel 94 winds the polishing tape T out of both rotation directions of the rotating shaft 130, and rotation in the direction in which the polishing tape T is unwound from the tape winding reel 94. It is a clutch to prevent. Therefore, according to the present embodiment, even if the crankshaft 10 tries to pull in the polishing tape T during polishing, the one-way clutch 120 causes the tape take-up reel 94 to rotate.
Is reliably prevented from rotating in the direction in which the polishing tape T is unwound, so that loosening of the polishing tape T during polishing is reliably prevented.

The engagement between the rotating shaft 130 and the motor 126 is performed by a meshing clutch 132, which is an example of a clutch mechanism.
134. A meshing clutch 132 (driven side engaging member) is mounted on the rotating shaft 130, and a meshing clutch 134 (drive side engaging member) is integrally rotatably mounted on the motor 126.

However, a pair of meshing clutches 132,
As described above, 134 is not always engaged, and is engaged only when the polishing is not being performed and the polishing unit U is positioned at a specific position. As shown in FIG. 6, when the pin portion 14 of the crankshaft 10 is polished, the pair of cartridges 70 is swung in a vertical plane as described above. Therefore, if the motor 126 is always engaged with the motor, measures must be taken to prevent the wire extending from the motor 126 from being cut, and the weight of the entire cartridge 70 increases. Therefore, in this embodiment, the motor 126 is retracted from the cartridge 70 during polishing.

FIG. 8 shows the relationship between the motor 126 and the cartridge 70. This figure shows a case where the number of polishing units U is two, and
26 shows a case where the cartridge 26 is retracted from the cartridge 70. As shown in the figure, the motor 126 is attached to a slider 142 as a movable member.
A pair of guide bars 144 extending parallel to each other in the left-right direction are fixed to the frame 20, and a slider 142 is supported on the guide bars 144 so as to be slidable in the axial direction. The motor 126 is always connected to the engagement clutch 132 of the tape take-up reel 94 as shown in FIG.
And allows the cartridge 70 to swing in a vertical plane. And the clamp arm 3
The pin 126 is fitted into the pin hole 40 of the main body 36 of FIG. 8 and the air cylinder 152 extends the rod 154 in a state where the clamp arm 38 is positioned at a specific position. Then, the meshing clutch 134 of the motor 126 is meshed with the meshing clutch 132 of the tape take-up reel 94. After that, the motor 126 is rotated to rotate the tape winding reel 94. The technique for controlling the motor 126 will be described later in detail.

In the cartridge 70, as shown in FIG. 6, an unused polishing tape T is supplied to a tape supply reel 92.
And the tape supply reel 92
After the polishing tape T comes out of the cartridge 70 once, it is wound around the tape take-up reel 94. The front plate 150 facing the other cartridge 70 among the plurality of plates forming the outer surface of the cartridge 70 is opened at both ends thereof, and the openings serve as the outlet and the inlet of the polishing tape T, respectively. is there. In addition, the exit and the entrance respectively,
A guide roller 154 for guiding the polishing tape T is rotatably provided.

A through hole 158 is provided in each of the upper plate located at the uppermost position and the lower plate located at the lowermost position when mounted on the clamp arm 38 among a plurality of plates forming the outer surface of the cartridge 70. ing. This through hole 158
Is a drain hole that allows the working liquid that has adhered to the polishing tape T during the winding of the polishing tape T and entered the cartridge 70 to naturally drop and be discharged to the outside.

As shown in FIG. 6, the shoe 95 is detachably attached to the front plate 150 of the housing 90 by fastening means such as screws. The shoe 95 contacts both ends of the polishing tape T with the inner surface of a portion supported by the pair of guide rollers 154, and the portion contacts the journal surface or the pin surface of the crankshaft 10 (hereinafter referred to as “working surface”). (Collectively). In the present embodiment, the shoe 95 is a block having a V-shaped groove at the tip end, and simultaneously presses the polishing tape T against the processing surface of the crankshaft 10 at two locations separated in the circumferential direction thereof.

The shoe 95 is shaped so as to make intensive contact with the work surface of the work at two places along the circumferential direction of the work via the polishing tape T. It is possible to adopt various shapes, for example, a shape in which contact is made intensively in one place or a shape in which contact is made widely in one place. In addition, shoes are three or more places along the circumferential direction of the work,
In addition, it is also possible to form a shape that makes wide contact at each location.

In the present embodiment, the shoe 95
Are made of materials different from each other in a portion that comes into contact with the polishing tape T and a portion that is attached to the housing 90. Specifically, the portion that comes into contact with the polishing tape T is made of ceramics to improve abrasion resistance. The part to be attached to is made of steel. However, the shoe 95
Various materials can be adopted. For example, the portion that comes into contact with the polishing tape T can be an elastic body such as urethane that can be elastically deformed during polishing.

The cartridge 70 is inserted into the cartridge storage chamber 7.
4, it is necessary to prevent the cartridge 70 from being detached from the cartridge storage chamber 74 and to prevent the cartridge 70 from rattling in the cartridge storage chamber 74 during polishing. is there. Therefore, in the present embodiment, the cartridge 7
The lock mechanism is provided for the clamp arm 38 and the clamp arm 38. Hereinafter, the lock mechanism will be described with reference to FIGS. 6, 9, and 10.

As shown in FIG. 6, the rear plate 1 facing the front plate 150 among a plurality of plates constituting the outer surface of the housing 90.
At 70, a notch 172 is formed at a position corresponding to the lock chamber 104. This notch 1
Reference numeral 72 denotes a lock plate to be described later when the cartridge 70 is loaded into the cartridge storage chamber 74.
The cartridge 70 has a U-shape that is open to the open surface of the cartridge 70 and extends parallel to the rotation axes of the reels 92 and 94.

The lock plate 176 is mounted on the clamp arm 38 by a rotating shaft 180 as shown in FIG. The rotation shaft 180 penetrates a bottom plate 178 of the clamp arm 38 that forms the bottom of the cartridge storage chamber 74, and is rotatably supported by the bottom plate 178. A male screw portion 182 is formed on a portion of the rotary shaft 180 located inside the cartridge storage chamber 74, and one end of a lock plate 176 is screwed to the male screw portion 182. On the other hand, an operation unit 186 is fixedly attached to a portion of the rotation shaft 180 located outside the clamp arm 38.

A stepped surface 188 is formed at a substantially axially intermediate position of the rotary shaft 180, and a retainer 190 is held there. The retainer 190 is prevented from approaching the operation portion 186 by engaging the surface near the operation portion 186 with the stepped surface 188, while the surface near the lock plate 176 has the lock plate 17
Coil spring 1 as an elastic member in cooperation with 6.
92 are held. The spring 192 prevents the lock plate 176 from rotating unnecessarily with respect to the rotation shaft 180 due to its elastic force. Further, an E-ring 194 is attached to the tip of the rotating shaft 180 as a detachment preventing means for preventing the lock plate 176 from detaching from the rotating shaft 180.

The lock plate 176 is
When 0 is not stored in the cartridge storage chamber 74, it is at the unlock position. Fig. 1
0 (a), the lock plate 176 is located at a position extending horizontally, and is parallel to the notch portion 172 that will be present when the cartridge 70 is stored in the cartridge storage chamber 74, This is a position that allows the rear plate 170 of the cartridge 70 to pass through the lock plate 176.

On the other hand, the cartridge 70 is stored in the cartridge storage chamber 74 and the operator
By rotating the lock plate 6, the lock plate 1
Since there is a gap between the inner plate 76 and the inner surface of the rear plate 170 of the cartridge 70, the lock plate 176 is
It rotates together with 0 to reach the lock position. The lock position is
The lock plate 176 is located at a position orthogonal to the notch 172 as shown in FIG. The rear plate 170 is provided with a stopper 196 that prevents the lock plate 176 from rotating beyond the orthogonal position. When the lock plate 176 is at the lock position orthogonal to the notch 172 in this manner, the rear plate 170 of the cartridge 70 is prevented from passing through the lock plate 176, and the cartridge 70 is detached from the cartridge storage chamber 74. Will be blocked.

However, simply by making the lock plate 176 orthogonal to the notch 172, the lock plate 17
Since there is a gap between the cartridge 6 and the inner surface of the rear plate 170 of the cartridge 70, the cartridge 70 may rattle during polishing. Therefore, in the present embodiment, the lock plate 176 is screwed instead of being fixed to the rotating shaft 180. Accordingly, if the operator further rotates the operation portion 186 in the same direction even after the lock plate 176 reaches the lock position, the lock plate 176 is kept at the lock position by the stopper 196, and thus such a lock is performed. The operation unit 186 approaches the plate 176. As a result, the rear plate 1 of the cartridge 70 is
The clamp 70 and the clamp arm 38 are strongly sandwiched, and the rattling of the cartridge 70 during polishing is reliably prevented.

The amount by which the polishing tape T is wound up by the motor 126 in the cartridge 70 is detected by the winding amount detecting device, and the accumulated amount of the used polishing tape T is detected by the accumulated amount detecting device.

In this embodiment, as shown in FIGS. 6 and 11, the winding amount detecting device 200 comprises: (a) a gear 202 which rotates with the winding of the polishing tape T by a motor 126; The amount of rotation of the gear 202 is determined by polishing tape T
Take-up amount sensor 20 that electrically detects the take-up amount of
4 is included. In the present embodiment, the gear 202 is located outside the cartridge 70.
The pair of guide rollers 154 is coaxially fixed to the uppermost roller when the cartridge 70 is mounted on the clamp arm 38. On the other hand, in the present embodiment, the winding amount sensor 204 is
Attached to. The cartridge 70 is mounted on the clamp arm 38 at a position close to and opposed to the gear 202. Further, the winding amount sensor 204 is a proximity switch that magnetically detects each of a plurality of teeth formed at a constant pitch on the outer peripheral surface of the gear 202 and outputs a signal corresponding thereto.

On the other hand, in the present embodiment, as shown in FIGS. 6 and 11, (a) the accumulated amount detecting device 210 is provided outside the tape take-up reel 94 around which the used polishing tape T is wound. It is configured to include a plunger 212 as a displacement member that is displaced in accordance with the diameter, and (b) an accumulation amount sensor 214 that electrically detects the displacement of the plunger 212 as an accumulation amount of the used polishing tape T. I have.

As shown in FIG. 11, the plunger 212 includes a rear plate 170 of the cartridge 70 and the clamp arm 3.
8 at the same time, and both ends thereof are respectively taken up by the tape take-up reel 94 and the clamp arm 3.
8 and a storage amount sensor 214 attached to the storage unit 8. The plunger 212 is connected to the clamp arm 3.
8 and is always urged in a direction to approach the tape take-up reel 94. However, the inner end of the plunger 212 contacts the outer diameter only when the outer diameter of the tape take-up reel 94 in a state where the used polishing tape T is wound exceeds the set value. As the outer diameter increases, the clamp arm 38 is displaced outward. The accumulation amount sensor 214 is a proximity switch that magnetically detects that the outer end of the plunger 212 has entered the detection range, and outputs a signal corresponding to the detection.

As described above, the winding of the polishing tape T in the cartridge 70 is performed by the motor 126, the winding amount sensor 202, and the accumulation amount sensor 204. The control of the motor 126 is performed by the controller 22.
Performed by 0. The controller 220 includes a CPU 222, a ROM 224, and a RAM, as shown in FIG.
226 is mainly configured. The winding amount sensor 202 and the accumulation amount sensor 212 are connected to the input side of the controller 220, and the motor 126 is connected to the output side. A warning device 232 is also connected to the output side to warn the operator that the time to replace the cartridge 70 is approaching because the accumulated amount of the used polishing tape T has exceeded the set value.

The polishing tape control routine shown in the flowchart of FIG. 13 is stored in the ROM 224 in advance, and the CPU 222 stores the routine in the RAM 226.
The polishing tape T is fed by executing the polishing tape T while utilizing.

The polishing tape control routine is repeatedly executed. At the time of each execution, first, in step S10 (hereinafter, referred to as “step S10”).
It is simply represented by “S10”. In the same manner for other steps), the accumulated amount sensor 212 determines whether the accumulated amount of the used polishing tape T on the tape take-up reel 94 is equal to or larger than a set value. Assuming that the value is not equal to or greater than the set value this time, the determination is NO, and in S20, whether or not one-time polishing has been completed is determined via a flag in the RAM 226 indicating whether or not polishing of one workpiece has been completed. It is determined whether or not. Assuming that the processing has not been completed this time, the determination is NO, and one execution of this routine ends immediately.

Thereafter, if it is assumed that one polishing operation is completed without the accumulated amount of the used polishing tape T being equal to or more than the set value while the execution of this routine is repeated many times, the determination in S10 is made. Is NO, the determination in S20 is YES, and in S30, a drive signal is output to the motor 126 engaged with the tape take-up reel 94, and
At 40, the winding amount sensor 204 determines whether the winding amount of the polishing tape T has reached a set value. The output of the drive signal to the motor 126 is performed until the winding amount of the polishing tape T reaches the set value. If the amount reaches the set value, the determination in S40 becomes YES, and one execution of this routine ends.

Thereafter, if it is assumed that the accumulated amount of the used polishing tape T has become equal to or larger than the set value while the execution of this routine is repeated many times, the determination in S10 becomes YES, and in S50, the alarm By 232, the operator is notified that it is almost time to replace the cartridge 70. This completes one execution of this routine.

When the operator determines that the cartridge 70 needs to be replaced, the operator stops the operation of the polishing system and positions the polishing unit U at a specific position (work replacing position, cartridge replacing position, etc.). The crankshaft 10 is retracted from the cartridge 70 by separating the pair of clamp arms 38 from each other. continue,
The crankshaft 10 is detached from the work holding device 26, and then the operating portion 186 is operated to
76 is the unlock position, and the cartridge 7 to be replaced
0 is pulled out from the clamp arm 38. Subsequently, a new cartridge 70 is mounted on the clamp arm 38, and the operation unit 186 is operated to set the lock plate 176 to the lock position.

When replacing the tape supply reel 92 and the tape take-up reel 94 in the cartridge 70, the operator moves the tape supply reel 92 and the tape take-up reel 94 from the rotating shafts 110 and 130, respectively. Remove and replace. At this time, the polishing tape T is
5 and is adjusted by the tape take-up reel 94 so as not to cause slack.

When replacing the tape supply reel 92 and the tape take-up reel 94 in the cartridge 70, the operator needs to directly touch the polishing tape T. However, when replacing the polishing tape T in the polishing unit U, it is only necessary to replace the cartridge 70, so that the operator can replace the polishing tape T without directly touching the polishing tape T, The replacement work of the polishing tape T is simplified, and the time required for replacement is reduced.

In this embodiment, since the shoe 95 as a pressing member is provided not on the main body of the polishing unit U but on the cartridge 70 itself, when replacing the polishing tape T, the polishing tape T The operation of retracting the shoe 95 from the shoe 95 or making the shoe 95 contact the shoe 95 is not essential. Therefore, according to the present embodiment, the operation of replacing the polishing tape T is further simplified.

The shoe 95 is a component that needs to be replaced in some cases during maintenance. On the other hand, in the present embodiment, the shoe 95 as the pressing member is attached to the cartridge 70, and the shoe 95 can be replaced while the cartridge 70 is removed from the polishing unit U. Therefore, according to the present embodiment, the operation of replacing the pressing member itself is simplified, and the effect of further improving the maintainability of the polishing apparatus can be obtained.

In the conventional polishing apparatus, the scheduled polishing portion of the work is revolved around the rotation axis of the work during polishing, and the polishing unit follows the scheduled polishing portion. Therefore, the polishing unit is attached to the main body of the polishing device. The tape supply unit that supplies the polishing tape to the polishing unit and the tape winding unit that winds the polishing tape are fixed to the main body of the polishing apparatus while being movably held in a plane perpendicular to the polishing unit.
Therefore, when the polishing unit moves during polishing, the relative positional relationship between the polishing unit and the tape supply unit and the tape winding unit changes accordingly. A special mechanism to prevent sagging or sagging is essential. On the other hand, in the present embodiment, the tape supply unit and the tape winding unit can be moved integrally with the polishing unit, and no force is generated in the polishing tape to pull or loosen it during polishing. Therefore, according to the present embodiment, a special mechanism for preventing cutting and loosening of the polishing tape during polishing is not indispensable, and the effect that the cost of the apparatus can be reduced can be obtained.

In the conventional polishing apparatus shown in FIG. 14, one polishing tape T is in contact with the same processing surface of the workpiece W at two places at the same time, and the pair of shoes 400 is separated from each other. The polishing tape T is pulled. Therefore, the guide roller 406 located above the pair of shoes 400 is elastically supported by the clamp arm 402 so as to approach the shoes 400. In contrast,
In the present embodiment, since the two independent polishing tapes T simultaneously contact the two positions of the workpiece W, the polishing tape T is not pulled when the pair of shoes 95 are separated from each other. Therefore, according to the present embodiment, the roller elastic support structure, which is indispensable in the conventional polishing apparatus, is no longer indispensable, so that an effect that the cost of the apparatus can be reduced can be obtained.

In this embodiment, the properties of the working fluid used for polishing are the same between the _two polishing tapes T ₁ and T ₂ , but may be different from each other.

Further, in the present embodiment, the feed timing and feed amount of the polishing tape are made to coincide with each other between the pair of polishing tape holding portions. For example, at least one of the feed timing and the feed amount is set to be equal to each other. Can be different.

While the preferred embodiment of the present invention has been described in detail with reference to the drawings, various modifications and changes may be made based on the knowledge of those skilled in the art without departing from the scope of the claims.
The present invention can be implemented in an improved form.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a polishing system for performing a polishing method according to an embodiment of the present invention.

FIG. 2 is a plan view showing a part of a crankshaft which is an example of a workpiece to be polished by the polishing method.

FIG. 3 is an enlarged side view showing the work rotating device and its peripheral portion in FIG. 1;

FIG. 4 is an enlarged front view showing a rotating body and its peripheral portion in FIG. 3;

FIG. 5 is an enlarged front view showing the polishing unit in FIG. 1;

FIG. 6 is an enlarged perspective view showing a pair of cartridges in FIG. 5;

7 is a cross-sectional view illustrating a rotation support mechanism of a tape supply reel in the cartridge in FIG.

8 is a partial front sectional view showing a motor for winding an abrasive tape in the cartridge in FIG. 6 and a peripheral portion thereof.

9 is an enlarged side sectional view showing a lock mechanism of the cartridge in FIG. 5;

FIG. 10 is a front view showing an unlocked state and a locked state of the lock mechanism of FIG. 9, respectively.

11 is a front view showing a state in which a winding amount sensor and an accumulation amount sensor are provided on the clamp arm in FIG. 5, respectively.

FIG. 12 is a block diagram showing electrical components of the polishing system.

FIG. 13 is a flowchart showing a polishing tape control routine stored in advance in a ROM in FIG. 12;

FIG. 14 is a front view showing a conventional polishing apparatus.

[Explanation of symbols]

T ₁ , T ₂ Polishing tape U Polishing unit 10 Crankshaft 22 Clamp unit 24 Polishing tape holder 26 Work holding device 28 Work rotating device 30 Vibration device 64 Main body 70 Cartridge 92 Tape supply reel 94 Tape take-up reel 95 Shoe 126 motor

Continuation of front page (56) References JP-A-3-251358 (JP, A) JP-A-1-307920 (JP, A) JP-A-7-75953 (JP, A) JP-A-61-209457 (JP) , A) JP-B63-35084 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B24B 21/00

Claims (3)

(57) [Claims] 1. A method for polishing a work with a polishing tape, wherein the polishing tape is two polishing tapes having different surface roughnesses to which abrasive grains are adhered, and the two polishing tapes are used for polishing the work. A polishing method characterized in that the work is rotated about its axis while being simultaneously pressed at two predetermined polishing positions facing each other with the work separated on a cylindrical processing surface. 2. The polishing method according to claim 1, wherein said work is reciprocated in the direction of its rotation axis simultaneously with said rotation. 3. A polishing tape holding part for holding the two polishing tapes via a pair of cartridges detachable from the polishing tape holding part. 3. The polishing method according to 1 or 2.