JP2641640B2 - Automatic polishing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic polishing apparatus for polishing an end surface of a steel material or the like.

[0002]

2. Description of the Related Art Generally, a large number of equipment pipes are laid in various plants and the like. Many of these pipes are formed by connecting a fixed-length steel pipe or a steel pipe that has been bent in advance by welding.

[0003] The connection of this pipe by welding is almost a local operation. The welding of these steel pipes may cause poor welding due to rust generated at the end of the pipe or dirt attached to the end of the pipe, thereby impairing the confidentiality of the pipe path. For this reason, when laying pipes,
Grinding around the connection of steel pipes is an important task.

[0004] The polishing operation of the steel pipe must be performed on both the outer peripheral surface and the inner surface of the steel pipe. A sandpaper wheel or the like is attached to a hand-held grinder, and an operator manually performs the polishing operation.

[0005]

However, in a large plant or the like, the number of welding points of the pipes increases, and a large amount of labor is required for polishing the pipes. The work of polishing the pipe may be a work at a high place, and even when the work is performed on the floor, the worker may have to perform the work in an unreasonable posture such as a middle waist. Therefore, there is a problem that the working efficiency is deteriorated in terms of the working environment and the working posture.

The present invention has been made in view of the above facts.
It is another object of the present invention to provide an automatic polishing apparatus that can easily and efficiently polish the end of a member to be polished such as a steel material having various shapes .

[0007]

Means for Solving the Problems] automatic polishing apparatus according to the present onset Ming is an automatic polishing apparatus for polishing the ends of the abrasive member, wherein are arranged corresponding to the end portion of the polishing member a frame that, a drive wheel which moves along said axial end of one of the peripheral surface abuts the abrasive member of the inner peripheral surface of the end portion of the polishing member, to drive the front Stories drive wheel A driving source, and a driven wheel that abuts against the other peripheral surface of the end of the polished member facing the driving wheel and moves while nipping the end of the polished member together with the driving wheel; a first polishing unit, said drive wheel to said first polishing means axis to polish while moving along the front SL one peripheral surface axially supported by the drive wheel <br/> co to the frame
Swingably supported and held in a predetermined swinging position
A first holding means, and a second polishing means for polishing while moving along the circumferential surface of the front SL other to be pivotally supported to the frame the driven wheel <br/> co, the said driven wheel first Shaft second polishing means
Swingably supported and held in a predetermined swinging position
And a second holding means .

[0008]

[0009]

SUMMARY OF] The onset Ming automatic polishing apparatus, placing the frame on the end of the polishing member, made to correspond to the driving wheel and the first abrasive member in the one peripheral surface, and a driven wheel on the other peripheral surface and the The two polishing members correspond.

In this automatic polishing apparatus, an end of a member to be polished is held between a driving wheel and a driven wheel, and the driven wheel is driven to move along the peripheral surface at the tip of the member to be polished. As the driving wheel and the driven wheel move, the first polishing means and the second polishing means respectively grind one peripheral surface and the other peripheral surface of the end of the member to be polished.

[0011] With this configuration, the first polishing means and the second polishing means can simultaneously polish both surfaces of the end of the member to be polished while running along the peripheral surface of the end of the steel material. .

[0012] The driving wheel and the driven wheels, each first holding means
And the first holding means and the second holding means are swingably attached to the frame by the second holding means.
I have. Thereby, even if the thickness of the member to be polished is different,
A drive wheel and first abrasive member abutted to one of the circumferential surface of the polishing member, its a second polishing means and the driven wheel to the other peripheral surface
Since respectively brought into contact can be held, it can be polished to ensure clamping the polished member.

[0013] Further, not only the thickness of the member to be polished is different, but also a portion formed in a fixed arc shape at the end of the tubular member or the like can be reliably sandwiched and polished. Further, by swinging the driving wheel and the driven wheel, attachment and detachment from the member to be polished can be facilitated.

As the material of the member to be polished to which the present invention is applied, a metal member such as a steel material, glass, resin or the like can be applied. Can be applied.

Further, as a driving source of the driving wheels, an electric motor may be used, but an air motor or the like may be used.

Further, as the first and second polishing means,
It is preferable that the end of the member to be polished is uniformly polished from the tip with a predetermined width. For example, a member in which sandpaper or the like is arranged on the outer peripheral surface of a cylindrical roller and the roller is rotated at high speed can be applied.

[0017]

1 to 3 show an automatic polishing apparatus 10 according to the present embodiment. The automatic grinding apparatus 10, the
It is attached to a steel pipe 11 shown as an example of a polishing member.
The steel pipe 11 has an arc-shaped end .

As shown in FIGS. 1 and 3, the automatic polishing apparatus 10 includes a frame 12 which is a long rectangular box.
Is provided. L-shaped frames 14 and 16 are fixed to the frame 12 on the side corresponding to the end surface of the steel material 11. These frames 14 and 16 have their middle portions in the longitudinal direction parallel to each other, and their distal ends are bent in directions facing each other to form bent portions 14A and 16A.

As shown in FIG. 3, the bent portions 14A, 1
6A, the frame 12 at the position opposing the
A substantially cylindrical bearing portion 18 having a through-hole communicating with the inside thereof is provided in a protruding manner. The shaft 20 is inserted into the bearing portion 18, and the bearing 2 provided on the inner surface of the bearing portion 18 is provided.
It is supported by 2. A gear 24 is fixed to the shaft 20 inside the frame 12.

On the other hand, a motor 26 is mounted on the frame 14. The drive shaft 26A of the motor 26 is
The gear 28 is fixedly inserted into the frame 12. Further, a plurality of shafts 3 are provided inside the frame 12.
0 is supported in parallel with the drive shaft 26A, and gears 32 and 33 are fixed to these shafts 30, respectively. The gear 28 of the motor 26 and the gear 24 of the two shafts 20 mesh with the gears 32 and 33 of the shaft 30 to rotate the drive shaft 26A of the motor 26 between the two shafts 20.
To be communicated to. The two shafts 20
Rotate in opposite directions.

As shown in FIGS. 1 and 3, the frame 1
A spring case 34 projects from each of the bent portions 14A and 16A toward the side opposite to the frame 12. These spring cases 34 are substantially cylindrical, and as shown in FIG.
And are formed coaxially.

A compression coil spring 36 is accommodated in these spring cases 34, and the compression coil springs 3
6, a substantially disc-shaped bearing bracket 3 is provided on the frame 12 side.
8 are provided. These bearing brackets 38 are arranged coaxially with the spring case 34 and are slidable in the axial direction along the inner surface of the spring case 34.

On the opposite side of the bearing bracket 38 from the frame 12, there is formed a pull-out knob 40 projecting from the spring case 34. A bearing 42 is fixed to the bearing bracket 38 on the frame 12 side.

The bearing 42 is urged toward the frame 12 by the compression coil spring 36.
By pulling “0” in the direction opposite to the frame 12, it moves in a direction away from the frame 12 against the urging force of the compression coil spring 36. By the movement of the bearing 42, polishing wheels 44 and 46 serving as first and second polishing means can be mounted between the bearing 42 and the bearing 22.

As shown in FIGS. 1 and 3, the grinding wheels 44 and 46 have the same shape as each other, and as shown in FIG.
And a shaft 50 which is coaxially fixed to the shaft.

A protrusion 50A is formed at the end of the shaft 50 on the bearing 22 side, and a recess 20A corresponding to the protrusion 50A is formed at the end of the shaft 20. Further, the distal end of the shaft 50 on the bearing 42 side is reduced in diameter, and a convex portion 50B is formed at the distal end. A concave portion 42B corresponding to the convex portion 50B is formed in a cap 42A which is supported by the bearing 42.

The grinding wheels 44 and 46 are provided with a shaft 50.
Is inserted into the concave portion 20A of the shaft 20, and the convex portion 50B is inserted into the concave portion 42B of the cap 42A. The protrusions 50A and 50B of the shaft 50 are brought into close contact with the shaft 20 and the bearing 42 by the urging force of the compression coil spring 36, and the rotation of the motor 26 can be transmitted. When the rotation of the motor 26 is transmitted, the polishing wheels 44 and 46 rotate. In addition, polishing wheel 4
When a load equal to or more than a certain load is applied to the portions 4 and 46, the protrusion 50
A, 50B and the sliding motor 26 between the recesses 20A, 42A.
Is not overloaded.

Polishing roller 48 of polishing wheels 44 and 46
A polishing member formed by uniformly bonding abrasives is fixed to the outer peripheral surface of the polishing pad. This polishing member polishes the surface of the steel pipe 11 by rubbing against the surface of the steel pipe 11. A wire brush or the like can be used as the polishing member.

As shown in FIGS. 1, 2 and 4, near the frame 14, a handle 52 having a substantially U-shaped outer shape is provided. The middle part of this handle 52
The grinding wheel 44 is parallel to the axial direction. As shown in FIG. 4, at the tip of the handle 52, disk-shaped eccentric wheels 54 are formed coaxially with each other.
FIG. 4 shows the handle 52 on the frame 12 side.

As shown in FIGS. 3 and 4, these eccentric wheels 54 have eccentric holes 56 into which the bearings 18 of the frame 12 are inserted and eccentric holes 58 into which the spring case 34 of the frame 14 is inserted. Each is drilled coaxially. The bearing 18 and the spring case 34 are rotatably inserted into the eccentric wheel 54, respectively. By rotating the handle 52 in the direction indicated by the arrow A or in the direction opposite to the direction indicated by the arrow A as shown in FIGS. 2 and 4, the eccentric wheel 54 causes the eccentric wheels 54 to rotate about the axes of the eccentric holes 56 and 58. It rotates eccentrically.

Each of the eccentric wheels 54 of the handle 52 has a driving wheel frame 60 constituting a first holding means.
Are disposed. This drive wheel frame 60 is formed by joining both ends in the longitudinal direction of a pair of side plates 62, and as shown in FIG. 3, a through hole 62B into which an eccentric wheel 54 is inserted is formed at an intermediate portion. The provided substantially arc-shaped support portion 62A is formed. The drive wheel frame 60 is rotatably supported by an eccentric wheel 54 inserted into the through hole 62B. Further, on the outer peripheral surface of the eccentric wheel 54 of the spring case 34 side, coaxially groove 54A is formed in the groove 54A, separation preventing has been made by the supporting section 6 2 A enters.

As shown in FIGS. 2 and 4, the drive wheel frame 60 reciprocates along the longitudinal direction of the frame 12 by rotating the handle 52 in the direction of arrow A and in the direction opposite to the direction of arrow A. That is, it is relatively movable with respect to the polishing wheel 44. A biasing means (not shown) is provided between the support portion 62A and the eccentric wheel 54, and is biased in a direction opposite to the direction of arrow A, so that the grinding wheel 44 is tightly attached to the outer peripheral surface of the steel pipe 11. Adhered to. By turning the handle 52 in the direction of arrow A against this urging force, the polishing wheel 44 is separated from the outer peripheral surface of the steel pipe 11.

As shown in FIG. 2, the drive wheel frame 6
A drive wheel 64 is provided at one end in the longitudinal direction of the zero. The drive wheel 64 is attached to a drive shaft 64A that is supported by a pair of side plates 62. Also. Drive wheel 64
Is provided in the drive frame near the motor 66 as a drive source.
Is attached, and rotation of the motor 66 is transmitted to the transmission unit 66.
The drive wheel 64 is transmitted to the shaft 64 </ b> A via A and the drive wheel 64 is rotated.

As shown in FIGS. 1 and 2, a wheel 68 is provided at an end of the drive wheel frame 60 opposite to the drive wheel 64 in the longitudinal direction. The wheels 68 are attached to a shaft 68A that is pivotally supported by the pair of side plates 62.

As shown in FIG. 2, the polishing wheel 44 and the drive wheel frame 60 which are relatively moved by the rotation of the handle 52 are moved toward and away from the steel pipe 11 between the drive wheel 64 and the wheel 68. . Accordingly, the drive wheel 64, the wheel 68, and the grinding wheel 44 can be brought into contact with the outer peripheral surface of the steel pipe 11 regardless of the outer diameter of the steel pipe 11. The polishing wheel 44 is composed of the driving wheel 64 and the wheel 6
8, the polishing wheel 44,
The drive wheel 64 and the wheel 68 can be in contact with the same plane, that is, a flat plate.

On the other hand, as shown in FIG. 2, a driven wheel frame 80 constituting the second holding means is provided near the grinding wheel 46. The driven wheel frame 80
A pair of side plates 82 are provided on both sides of the polishing wheel 46 in the axial direction, and these side plates 82 are connected to each other. As shown in FIG. 3, each of the pair of side plates 82 is formed with a substantially arc-shaped support portion 82 </ b> A.
A through hole 82B into which the bearing portion 18 is inserted and a through hole 82C into which the spring case 34 is inserted are formed.

As shown in FIG. 2, the driven wheel frame 8
0 is provided with a driven wheel 84 on the drive wheel 64 side of the support portion 82A. The driven wheel 84 is attached to a shaft 84 </ b> A that is supported by the pair of side plates 82.

On the other hand, as shown in FIG. 2, a bracket 70 protrudes from the front end of the drive wheel frame 60 on the wheel 68 side. In addition, the polishing wheel 46 of the frame 12
In the vicinity, a bracket 72 is provided so as to correspond to the bracket 70. A support plate 74 extends between these brackets 70 and 72. An oblong hole 74 </ b> A is formed at an end of the support plate 74 on the bracket 70 side along the longitudinal direction of the support plate 74.

The support plate 74 is fixed to the bracket 72 by bolts 76A and nuts 76B, and the bracket 70 is provided with a thumbscrew 78 inserted into the oblong hole 74A.
Is fixed by screwing. Thus, the frame 12 is supported by the supporting portions 62A of the side plates 62 in a state where the driving wheels 64 and the wheels 68 of the driving wheel frame 60 are in contact with the outer peripheral surface of the steel pipe 11.
, And the polishing wheel 46 can be fixed in a state of contact with the inner surface of the steel pipe 11.

As shown in FIGS. 1 and 2, the side plate 82 of the grinding wheel 46 opposite to the driven wheel 84 has its tip bent toward the opposite side of the wheel 68 of the drive wheel frame 60, and is bent. A shaft 86 is hung over and connected to the distal end. A support bracket 88 is inserted into the intermediate portion of the shaft 86 and is supported by the shaft. The support bracket 88 has a support shaft 88A protruding in the radial direction. In the middle of the frame 16, the frame 12
A bracket 90 is protrudingly provided on the distal end side in the longitudinal direction. A stopper 92 is pivotally supported by the bracket 90. The stopper 92 is inserted into the support shaft 88A so as to be slidable in the axial direction.

A thumb screw 94 is screwed into the stopper 92. The tip of the thumbscrew 94 contacts the outer peripheral surface of the support shaft 88A inside the stopper 92 (not shown).
It can be fixed at any position along the axial direction of 8A. Thereby, the driven wheel 84 that swings around the axis of the polishing wheel 46 can be fixed at an arbitrary position,
With the polishing wheel 44, the driving wheel 64, and the wheel 68 all in contact with the outer peripheral surface of the pipe 11, the polishing wheel 46 and the driven wheel 84 can be fixed in contact with the inner surface of the pipe 11. . At this time, the steel pipe 11 is held by the drive wheel 64, the wheel 68, and the driven wheel 84 while being pressed from both the outer peripheral surface and the inner surface.

Next, the automatic polishing apparatus 1 applied to this embodiment
The operation of 0 will be described. FIGS. 1 and 2 show a state in which the automatic polishing apparatus 10 is mounted on a steel pipe 11. When the automatic polishing apparatus 10 is mounted on the steel material 11, the automatic polishing apparatus 10 is inserted from outside the pipe 11 in the axial direction, and the drive wheel frame 60 is disposed outside the pipe 11 and the driven wheel frame 80 is disposed inside. Drive wheel 6 of drive wheel frame 60
After the wheel 2 and the wheel 68 are brought into contact with the outer peripheral surface of the pipe 11, the handle 52 is rotated in the direction opposite to the arrow A direction. Thus, the polishing wheel 44 can be brought close to and contact with the outer peripheral surface of the steel pipe 11, and the polishing wheel 44, the driving wheel 62 and the wheel 68 contact the outer peripheral surface of the steel pipe 11. The polishing wheel 44 moves relative to the driving wheel 64 and the driven wheel 68, so that the polishing wheel 44, the driving wheel 64 and the wheel 68 are respectively moved to the steel pipe 11 even if the outer diameter of the steel pipe 11 is different.
Can be brought into close contact with the outer peripheral surface of the. In this state, the handle 52 is urged toward the outer peripheral surface of the steel pipe 11 by urging means (not shown).

In this state, the frame 12 is rotated about the grinding wheel 44 so that the grinding wheel 46 presses the inner surface of the steel pipe 11.
Is fixed with a thumbscrew 78. As a result, the frame 12 and the drive wheel frame 60 are fixed. This fixed state can be adjusted according to the wall thickness of the steel pipe 11 by the oval hole 74A formed in the support plate 74.

Further, the driven wheel frame 80 is rotated so that the driven wheel 82 presses against the inner surface of the pipe 11, and the support shaft 88A and the stopper 92 are fixed by the thumb screw 94. Thus, the grinding wheel 46 and the driven wheel 84 can be closely adhered to the inner surface of the steel pipe 11 according to the inner diameter of the steel pipe 11.

In this state, the automatic polishing apparatus 10
Grinding wheel 44, driving wheel 62, and wheel 68 in contact with the outer peripheral surface of the steel pipe 11, and polishing wheel 4 in contact with the inner surface of steel pipe 11.
6 and the driven wheel 82 hold the steel pipe 11 in a pressed state, and the automatic polishing device 10 is mounted on the end of the steel pipe 11.

When the automatic polishing apparatus 10 is mounted on the steel pipe 11 and the motor 66 is turned on, the drive wheel 64 is driven, and the outer peripheral surface of the steel pipe 11 moves along the end. As the drive wheel 64 moves, the wheel 68 and the driven wheel 84
Moves, and the automatic polishing apparatus 10 moves in a stable state along the end of the pipe 11.

When the motor 26 of the automatic polishing apparatus 10 is turned on, the gear 3 provided inside the frame 12 is turned on.
The grinding wheels 44, 46 are driven via 2, 33,
The outer peripheral surface and the inner surface of the steel pipe 11 are polished by a polishing member provided on the outer peripheral surface of the polishing roller 48. Polishing wheel 4
The polishing wheel 4 and the grinding wheel 46 are rotated in the opposite directions by the rotation of the motor 26. Each of the grinding wheels 44 and 46 and the surface of the steel pipe 11 rub against each other, so that the automatic grinding device 10 can travel. It has no effect.

As a result, the automatic polishing apparatus 10 can stably move along the end of the steel pipe 11 and can uniformly polish the outer and inner surfaces of the end of the steel pipe 11 with the piping. To remove the drive wheel frame 11 from the drive wheel frame 11, it is only necessary to loosen the thumb screws 78 and 94 that fix the drive wheel frame 60 and the driven wheel frame 80 to the frame 12, respectively. As a result, the driving wheel 64, the wheel 68, and the polishing wheel 44 of the driving wheel frame 60 and the driven wheel 84 of the driven wheel frame 80
Then, the end of the pipe 11 held by the polishing wheel 46 is released, and the automatic polishing apparatus 10 can be easily removed from the steel pipe 11.

Next, an example in which the automatic polishing apparatus 10 according to this embodiment is used for a flat steel material, that is, a steel plate 13, will be described.

FIG. 5 shows a state in which the automatic polishing apparatus 10 is mounted on the steel plate 13. The mounting of the automatic polishing apparatus 10 on the steel plate 13 can be performed by the same operation as the mounting on the steel pipe 11. The drive wheel 64 and the wheel 68 of the drive wheel frame 60 are brought into close contact with the surface of the steel plate 13, and the handle 52 is rotated in the direction opposite to the direction of arrow A, and the polishing wheel 44 is moved together with the drive wheel 64 and the wheel 68 to the surface of the steel plate 13. You only need to make contact. Thereafter, the polishing wheel 46 and the driven wheel 84 are brought into contact with the steel plate 13, and the drive wheel frame 60 and the driven wheel frame 80 may be fixed to the frame 12 with the thumb screws 78 and 94.

The automatic polishing apparatus 10 mounted on the end of the steel plate 13 as described above is driven by the motors 26 and 66 to move along the end of the steel plate 13 while moving along the end of the steel plate 13. Can be polished simultaneously.

The automatic polishing apparatus 10 according to the present embodiment can be easily mounted at any end of the steel pipe 11 and the steel plate 13.

When the steel material is polished, the polishing powder is scattered. The automatic polishing apparatus 10 can suppress the scattering of the polishing powder by providing a means for sucking the polishing powder in the vicinity of the polishing wheels 44, 46. . The abrasive powder suction means may be provided on the downstream side in the rotation direction of each of the polishing rollers 48 in the vicinity where the polishing roller 48 comes into contact with the steel material. Since each of the polishing wheels 44 and 46 is rotating in a fixed direction, it is easy to attach the abrasive powder suction means.

For example, when the polishing wheel 44 is rotated in the direction of arrow A (shown in FIGS. 2 and 5), the polishing powder mainly scatters between the polishing wheel 44 and the wheel 48. A polishing powder suction means may be provided between the polishing wheel 44 and the wheel 48, and a polishing powder suction means between the polishing wheel 46 and the driven wheel 84 may be provided.

Incidentally, the polishing wheel 44 is constituted by the eccentric wheel 5.
4, it is possible to protrude from the drive wheel 64 and the wheel 68 toward the surface of the steel pipe 11 or the steel material 13 from the space between the drive wheel 64 and the wheel 68. However, the present invention is not limited to this. It may be possible to appear and disappear.
That is, an oval hole is formed in the frame 12 in an arc shape, and the shaft 20 of the polishing wheel 44 is movable along the oval hole while being supported by the shaft. The driving force of the motor 26 may be transmitted while maintaining the meshing state with the motor 33.

Further, in this embodiment, the automatic polishing apparatus for polishing the end portion of the steel material has been described, but a member of another material can be used as the member to be polished. That is, by changing the polishing member provided on the polishing wheel, it becomes possible to polish a member such as a glass, a resin, or a metal material other than steel.

[0057]

Automatic grinding apparatus of the present invention as has been described above moves while sandwiching a polished member by a driving wheel and a driven wheel, the first and second abrasive member, the end of the polishing member Both sides of the part can be polished simultaneously. Thus, the work of polishing the member to be polished only requires the operator to attach the automatic polishing device to the end of the member to be polished, and the working efficiency can be greatly improved. Further, since both surfaces of the member to be polished can be simultaneously polished while running along the end of the member to be polished, the operation time of the polishing operation can be reduced.

[0058] Further, automatic grinding apparatus of the present invention, the easier it der also mounted a tube be polished member flat,
In addition, mounting is easy regardless of the thickness of the member to be polished .

As described above, the automatic polishing apparatus according to the present invention
There is an excellent effect that the work of polishing the member to be polished can be easily and efficiently performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an automatic polishing apparatus according to an embodiment.

FIG. 2 is a main part side view showing the use of the automatic polishing apparatus according to the present embodiment.

FIG. 3 is a sectional view of an essential part taken along line 3-3 in FIG. 2;

FIG. 4 is a perspective view showing a main part of the automatic polishing apparatus according to the embodiment.

FIG. 5 is a side view similar to FIG. 2, showing a modification of the use of the automatic polishing apparatus according to the embodiment.

[Explanation of symbols]

 Reference Signs List 10 automatic polishing apparatus 11 steel pipe (member to be polished) 12 frame 13 steel plate (member to be polished) 44 polishing wheel (first polishing means) 46 polishing wheel (second polishing means) 64 driving wheel 66 motor (drive source) 84 Driven wheel

Claims (1)

(57) [Claims] 1. An automatic polishing apparatus for polishing an end of a member to be polished, comprising: a frame disposed corresponding to an end of the member to be polished; and inner and outer circumferences of the end of the member to be polished. a drive wheel which moves along the end portion in the axial direction of one of the peripheral surface abuts the abrasive member of the faces, and a driving source for driving the front Symbol driving wheels, the object to be opposite to the previous SL drive wheel a driven wheel that moves while sandwiching an end portion of the polishing member on the other of the peripheral surface of the end portion of the polishing member with contact drive wheels, the circumferential surface of the front Symbol one to axially supported by the drive wheel co to the frame A first polishing means for polishing while moving along the driving wheel;
The means is pivotally supported on the shaft and at a predetermined swing position.
A first holding means for holding, a second polishing means that is pivotally supported to the frame to Ken <br/> grinding while moving along the circumferential surface of the front SL other to the driven wheel and co, the driven wheel The second polishing
The means is pivotally supported on the shaft and at a predetermined swing position.
An automatic polishing apparatus , comprising: a second holding means for holding .