JPH0947958A - Lapping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a strain due to wear and elasticity of a press element to force a lapping tape into press contact with a cam shaft, to improve machining precision, to provide an increased life, and to reduce a machining cost. SOLUTION: In a lapping device 10 to polish the outer periphery of a cam shaft supported rotatably forward and reverse and in such a state to be capable of vibrating in an axial direction, the lapping device comprises a press element 30 supported at a holding body in such a manner to front on a cam shaft W; and a lapping tape the back of which is pressed by the press element and which is forced into pressure contact with the cam shaft. The press element 30 comprises a base body 32 having a head part 32a on the surface of which diamond powder is welded and which is movably forward and backward supported in a fitted-in state at the holding body 31; and an elastic body 33 embedded in the back of a base body and making elastic contact with the holding body 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lapping apparatus for simultaneously polishing a work surface on the outer periphery of a work that is supported so as to be rotatable in the forward and reverse directions and capable of axial vibration.

[0002]

2. Description of the Related Art As a conventional lapping device, there is one using a pressing element 30 shown in FIG. That is, for example, a workpiece W, which is a camshaft, is supported, and the workpiece W is supported so as to be capable of forward and reverse rotation and axial vibration, and the outer periphery of a plurality of cam surfaces of the workpiece W is simultaneously polished. Then, the wrapping tape 20 is wrapped around the outer circumference of the cam surface with a tension, and a part of the wrapping tape 20 is urged and pressed by the pressing member 1 made of an elastic material so that the pressing member 1 and the outer circumference of the cam surface are The wrapping tape 20 is sandwiched between the two to be ground. The wrapping tape 20 can be fed and held by a supply mechanism.

The pressing element 1 is entirely made of an elastic material such as urethane rubber, and the pressing element 1 is held by a holder 2 so as to be slidable back and forth.

[0004]

However, in such a conventional technique, since the pressing element 1 is formed of an elastic body as a whole, the wrapping tape is hard to slip.
Moreover, its elasticity allows it to closely follow the shape of the processed product and is easy to use, but it is easy to deform due to wear and distortion due to elasticity,
In addition, the accuracy of cam surface machining varies due to the difference in molding accuracy and hardness of the elastic body, and the service life and accuracy stability of the presser are somewhat inferior, and the processing conditions are severe and the usability is not sufficient. .

The present invention has been made by paying attention to the problems of the prior art as described above, and is characterized in that the pressing member made of an elastic material has a wrapping tape that is hard to slip and that it closely follows the shape of a processed product. It is an object of the present invention to provide a lapping device capable of reducing wear and distortion and reducing variations in processing accuracy of a cam surface without impairing the above.

[0006]

The gist of the present invention for achieving the above object is to provide a workpiece (W) on the outer periphery of a workpiece which is supported so as to be capable of forward and reverse rotation and capable of axial vibration. A lapping device (1 for simultaneously polishing the processed surface (W1)
In (0), a presser (30) supported by the holder (31) facing the surface to be processed and a wrapping tape (20) whose back surface is pressed by the presser (30) and presses against the surface to be processed. The pressing element (30) is embedded in a base (32) in which diamond powder is welded to the surface of the head facing the surface to be processed and fitted and supported by a holder (31) so as to be able to move forward and backward, and in the back of the base. And the elastic body (33) elastically contacting the holding body.

The above invention operates as follows.
The pusher (30) is a base (32) facing the wrapping tape.
Wear and deformation can be reduced by using a material having high rigidity such as metal. The pusher (30) is composed of a base body (32) and an elastic body (33), and the base body (32) is held by a holding body (31) via the elastic body (33). Wrapping tape (2
0) is pressed, the elastic body (33) is compressed and the base body (32) is elastically urged to press the wrapping tape (20), resulting in a dimensional error of a surface to be processed such as a cam surface. Can respond.

The head portion (32a) of the substrate facing the surface to be processed
Since the diamond powder is welded to the surface of the lapping tape (20), the coefficient of friction with the back surface of the lapping tape (20) becomes larger, and the frictional force at the outer periphery of the rotating surface to be worked tends to move the lapping tape (20) being processed. It is possible to overcome the force exerted and ensure the fixation. Further, since the base body head portion (32a) has a high hardness due to the diamond powder, abrasion can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Each drawing shows an embodiment of the present invention. As shown in FIGS. 5 and 6, the lapping device 10 is for polishing a camshaft W as a workpiece, and the cam surfaces W1 and W that are the workpiece surfaces of the camshaft W.
A continuous wrapping tape 20, 20 ... arranged so that the outer periphery of 1 ...
A pusher 30 for biasing the outer periphery of the cam surface W1 of the camshaft W via a part of the wrapping tape 20,
A supply mechanism 70 capable of feeding the wrapping tape 20 is provided between the presser 30 and the outer periphery of the cam surface W1.

As can be seen from FIG. 5, a headstock 11 and a camshaft that support the base ends of the shafts of the camshafts W so as to be able to rotate in the forward and reverse directions so as to face each other on both front sides of the camshaft lapping device 10. A center headstock 12 that supports the tip of the W shaft so that it cannot swing is provided with guide bases 13 and 1, respectively.
4 is slidably arranged.

The headstock 11 and the center headstock 12 are integrally connected by a connecting rod 15.
2, a protruding member 12a is provided at a position opposite to the connecting rod 15, an oval through hole 12b is formed in the protruding member 12a, and the hydraulic motor 1 is disposed near the center headstock 12.
An eccentric cam shaft 16a that is fitted in the oval through hole 12b of the protruding member 12a is provided at the tip end of the output shaft 16b of No. 6.

As can be seen from FIG. 5, the camshaft W has four cam surfaces W1. As shown in FIG. 2, pressers 30 that can press the cam surface W1 via a part of the wrapping tape 20 are provided on both sides of the four cam surfaces W1 of the cam shaft W, respectively. ing.

As can be seen from FIGS. 2, 6 and 7,
The mechanism for pressing the cam surface W1 against the pusher 30 is symmetrically arranged about the rotation axis of the cam shaft W, and the pneumatic cylinder 41 rotates the T-shaped arm 43 via the vertical connecting rod 42. By moving, the pusher 30, which is attached to the lower portion of the T-shaped arm 43 via the pressure holding body 31, moves in the direction of pushing the cam surface W1.

The force with which the pressing element 30 presses the cam surface W1 of the cam shaft W via the wrapping tape 20 is controlled to be constant by the backward moving pneumatic cylinder 41.

As shown in FIGS. 8 and 9, the pusher 30 comprises a base 32 and an elastic body 33, and the base 32 is fitted in the concave fitting portion of the holder 31 so as to be slidable in the vertical direction in the drawings. The base 32 is fitted between the concave fitting portion on the back surface of the base 32 and the holding body 31 via an elastic body 33. Holder 31 and base 32
A sufficient gap is provided between the elastic bodies 33 to match the amount of deformation of the elastic body 33.

The substrate 32 is made of a metallic material by welding diamond powder to the head pressing surface 32a facing the wrapping tape. The elastic body 33 is formed of an elastic material (for example, urethane or nitrile rubber), and urges the base body 32 to elastically press the wrapping tape.

In FIGS. 2 and 5 to 7, the overhanging substrate 1 projecting forward from the mounting struts 17, 17 provided on both sides of the rear portion of the camshaft wrapping device 10, respectively.
The horizontal shafts 18a and 18a are provided so as to connect the Nos. 8 and 18, and the hanging metal fittings 18b are provided so as to be externally fitted to the horizontal shaft 18a. The return type pneumatic cylinder 41 is provided with the pivot pin 41a. Is attached to the hanging bracket 18b.

A ceiling board 19 is provided so as to connect the lower end portions of the overhanging boards 18, 18, and a vertical mounting plate 19a is hung and fixed to the ceiling board 19 and arranged at a predetermined position of the vertical mounting plate 19a. The one end 43a of the arm of the T-shaped arm 43 is rotatably supported by the pivot pin 19b.

The lower end of the vertical connecting rod 42 has a T-shaped arm 43.
Is connected to the other end 43b of the arm via a pivot 42a, and the upper end is connected to a piston rod 41b of a backward-moving pneumatic cylinder 41 so as to be screw-adjustable.

The wrapping tape 20 has a total length of 35 to 55 m.
Is formed in a continuous strip shape, and one surface of the wrapping tape 20 is coated with a wrapping material for finely finishing the cam surface W1.

A wrapping tape guide mechanism 50 and a tensioning / holding mechanism 60 are provided for arranging the wrapping tape 20 so that the cam surface W1 of the camshaft W is wound around the camshaft W1 with a tension.

As can be seen from FIGS. 2 and 7, the wrapping tape guide mechanism 50 is arranged symmetrically about the rotation axis of the camshaft W. The side guide roller holding frame 51 is provided at both sides of the cam surface W1 of the cam shaft W.
The pressure holding body 31 is fixed to the upper side of the cam surface W1 of the cam shaft W, and the upper guide roller holding frame 52 is fixed to the vertical mounting plate 19a. The side guide roller holding frame 51 and the upper guide roller holding frame 52 are provided with a predetermined number of guide rollers R, R ... In such a manner as to surround the cam surface W1 of the cam shaft W in an inverted U shape as a whole. The guide rollers R, R disposed above and below the pressing holder 31 are attached to the side guide roller holding frame 51 so that the wrapping tape 20 is along the base body head 32a of the pressing element 30.

As shown in FIG. 2 and FIGS. 6 and 7, the tensioning and holding mechanism 60 holds both lower sides of the wrapping tape 20 arranged so as to surround the camshaft W in an inverted U shape. The wrapping tape 20 with tension,
It prevents loosening.

In the tension holding mechanism 60, the sliding member 61 is T
The lower end of the mounting board 62 and the contactor 64 which is vertically guided by the guide pins 63, 63 of the mounting board 62 fixed to the outer side of the shaped arm 43 and fixed to the lower end of the sliding member 61. The guide surface 65 is formed so that the wrapping tape 20 can be held.

A convex member 66 is provided at the upper end of the sliding member 61.
The protruding member 66 is provided so as to face the pushing member 67, and the pushing member 67 is fixed to the front and rear end portions of the front and rear extension plate 68 attached to the lower end portion of the vertical mounting plate 19a. As can be seen from FIG. 6, the pushing member 67 is configured such that when the piston rod 41b of the backward-moving pneumatic cylinder 41 rotates the T-shaped arm 43 in the opening direction via the vertical connecting rod 42, the sliding member 61 is projected. The sliding member 61 is pushed down against the biasing force of the spring member 69 by abutting against the member 66, and the wrapping tape is provided between the contactor 64 of the sliding member 61 and the lower end guide surface 65 of the mounting substrate 62. 20 is formed so as to have a gap into which it can be inserted.

As shown in FIGS. 2, 3, 5, and 6, the supply mechanism 70 includes four cam surfaces W1 of the camshaft W.
The camshaft W is arranged so that the axial distance between the camshafts W can be adjusted. The supply mechanism 70 includes a winding frame 71 around which one end of the wrapping tape 20 is wound via each guide roller R, a winding roller 72 that winds up the other end of the wrapping tape 20 via each guide roller R, and And a winding frame 73.

The winding frame 71 is rotatably supported by a supporting frame 74 projecting upward from the mounting columns 17 and 17, and the winding frame 73 is rotated around the tip of the swinging member 75 of the overhanging substrate 18. It is movably pivoted.

Next, the operation will be described.

FIGS. 1, 2 and 5 and 6 show a state in which the camshaft lapping device 10 is processing the cam surface W1 of the camshaft W. The rotating shaft of the cam shaft W is rotated in the forward and reverse directions by the headstock 11 and the center headstock 12 without swinging its tip. Further, as the hydraulic motor 16 rotates, the eccentric cam shaft 16a of the hydraulic motor 16 rotates in the oval through hole 12b of the projecting member 12a, and the center headstock 12 moves on the guide base 14 in the A direction in FIG. Reciprocating motion (vibration due to an amplitude twice the eccentric distance of the eccentric cam) causes the headstock 11 to also reciprocate on the guide base 13 via the connecting rod 15, whereby the camshaft W also reciprocates. .

As can be seen from FIGS. 1 and 2, the T-shaped arm 4
The pusher 30 fixed to the No. 3 is located at the pushing position, and a predetermined amount of gap is formed between the pushing member 67 of the front-rear extension plate 68 and the convex member 66 of the sliding member 61, and the spring member. 69 pushes the sliding member 61 upward, and the contactor 64 of the sliding member 61.
Comes into contact with the lower end guide surface 65 of the mounting substrate 62 via the wrapping tape 20, whereby the wrapping tape 20
Is pinched immovably.

Therefore, even if the cam shaft W rotates and the wrapping tape 20 receives the frictional force of the cam surface W1, the wrapping tape 20 does not move. Further, since the wrapping tape 20 arranged in an inverted U-shape is sandwiched at both lower side positions, the wrapping tape 20 does not move even when the camshaft W rotates normally or reversely.

When the camshaft W rotates and the distance from the center of rotation of the camshaft W to the processed position of the cam surface W1 increases, the cam surface W1 is pressed by the pressing element 30 via the wrapping tape 20. , The lower end of the T-shaped arm 43 is pushed outward with the pivot pin 19b as the center,
The other end 43b of the arm of the T-shaped arm 43 is connected to the piston rod 41 of the backward-moving pneumatic cylinder 41 via the vertical connecting rod 42.
Push up b against the urging force.

From the center of rotation of the camshaft W to the cam surface W1
If the distance to the work position of
1 tries to separate from the wrapping tape 20, but the piston rod 41b of the backward-moving pneumatic cylinder 41 causes the T-shaped arm 43 to move the T-arm 43 at the lower end of the T-shaped arm 43 via the vertical connecting rod 42. Since the surface W1 is urged in the pressing direction, the wrapping tape 20 follows and presses the cam surface W1 that is about to leave. The cam surface W1 of the cam shaft W is polished as described above.

In FIG. 8 and FIG. 9, the pusher 30 is the base 3
2 and an elastic body 33, which are fitted and held by a holder 31. The elastic body 33 is, for example, urethane rubber.

The elastic body 33 is fitted in the concave fitting portion on the rear surface of the base body, and the convex portion of the base body 32 is fitted in the concave portion of the elastic body 33 also on the bottom surface of the concave fitting portion, and the elastic body 33 is also provided.
Since both end portions 33a and 33b of the elastic body 33 and the base body 32 are restrained by the side guide roller holding frame 51, the elastic body 33 and the base body 32 do not move or fall off.

When the pusher 30 presses the wrapping tape against the cam shaft, the elastic body 33 is compressed and the base body 32 is compressed.
Is elastically biased to press the wrapping tape, and can respond at high speed in accordance with the dimensional error of the cam surface.

Further, since the diamond powder is welded to the surface of the base head portion 32a facing the surface to be processed, the friction coefficient with the back surface of the lapping tape becomes larger, and the frictional force on the outer periphery of the rotating cam surface is being processed. It can overcome the force to move the wrapping tape and ensure the fixing. At the same time, the base body head portion 32a realizes high hardness by the diamond powder to prevent abrasion.

When the surface of the wrapping tape at the processing position is worn, in order to move the wrapping tape 20 to a new surface of the wrapping tape which is not worn, as shown in FIG. 7, a backward movement pneumatic cylinder is used. The air pressure of 41 is switched to the piston rod 41b of the backward-moving pneumatic cylinder 41.
Causes the vertical connecting rod 42 to be pulled upward.

As a result, the lower end of the T-shaped arm 43 rotates in the direction away from the cam shaft W about the pivot pin 19b, and when the T-shaped arm 43 rotates, the sliding member 6
The first convex member 66 comes into contact with the pushing member 67 of the front-back extending plate 68, and the sliding member 61 is pushed down against the biasing force of the spring member 69 while being guided by the guide pin 63. As shown in FIG. 7, a gap in which the wrapping tape 20 can be inserted is formed between the contactor 64 of the sliding member 61 and the lower end guide surface 65 of the mounting substrate 62.

Next, the winding roller 72 is driven to wind up one end of the wrapping tape 20 by a predetermined length, and
The winding frame 73 and the guide roller 76 attached to the swing member 75.
Thus, the wrapped wrapping tape 20 is wound up.
As a result, the wrapping tape 20 is guided and moved by the respective guide rollers R, and the wrapping surface of the wrapping tape 20 facing the cam surface W1 becomes a new non-wearing surface.
At this time, the same amount of the wrapping tape 20 moves downward from the winding frame 71.

Next, as shown in FIG. 7 to FIG. 2, the air pressure of the backward-moving pneumatic cylinder 41 is switched, the piston rod 41b of the backward-moving pneumatic cylinder 41 is pushed out, and vertically connected. The T-arm 43 is rotated via the rod 42 in a direction in which the pusher 30 approaches the camshaft W.

When the T-arm 43 is rotated, the sliding member 6
The convex member 66 of No. 1 is one end 19a of the arm of the T-shaped arm 43.
And the sliding member 6 is rotated by the spring member 69.
The convex member 66 of No. 1 moves upward while separating from the pushing member 67 of the front-back extending plate 68, and the sliding member 61 becomes the sliding member 6
The first contactor 64 contacts the lower end guide surface 65 of the mounting member 62 via the wrapping tape 20 and stops. As a result, the wrapping tape 20 is held immovably.

When the T-shaped arm 43 is further rotated, the convex member 66 of the sliding member 61 and the pushing member 6 of the front-rear extending plate 68.
As shown in FIG. When machining the outer circumferences of the cam surfaces of different types of camshafts, the air pressure of the backward-moving pneumatic cylinder 41 is adjusted so that the force pressing the outer circumference of the cam surface of the camshaft is adapted to it. can do.

When the lapping process is performed, the pneumatic cylinder 41 works and the pressing element 30 presses the lapping tape against the cam surface of the cam shaft.

[0045]

[Embodiment] FIG. 11 is measurement data showing an embodiment of the present invention, in which the processing accuracy is shown by the straightness indicating the height or depth of the unevenness with respect to the plane (straight line) of the processing surface.

[0046]

According to the wrapping device according to the present invention,
The pressing element is not made of urethane rubber alone, but is composed of a base body in which diamond powder is welded and fitted and supported by the holding body so as to be able to advance and retreat, and an elastic body embedded in the back part of the base body and elastically contacting the holding body. Because of the structure, distortion due to wear and elasticity is reduced, processing accuracy is improved, processing accuracy is improved, and the life of the presser is extended, so product quality can be improved and processing cost can be reduced. it can.

[Brief description of drawings]

FIG. 1 is a front view showing a main part of a lapping apparatus according to an embodiment of the present invention.

FIG. 2 is a front view showing the whole of the lapping device according to the embodiment of the present invention.

FIG. 3 is a view showing a main part of a lapping device according to an embodiment of the present invention, and is a view taken along the arrow III in FIG.

FIG. 4 is a IV arrow view of FIG. 2 showing a main part of the lapping apparatus according to the embodiment of the present invention.

FIG. 5 is a side view of the lapping device according to the embodiment of the present invention.

FIG. 6 is a VI arrow view of FIG. 5 showing a main part of the lapping apparatus according to the embodiment of the present invention.

FIG. 7 is a VI arrow view of FIG. 5 showing the operation of the lapping apparatus according to the embodiment of the present invention.

FIG. 8 is a perspective view of a main part including a presser of the lapping device according to the embodiment of the present invention.

FIG. 9 is a perspective view of a pusher of the lapping device according to the embodiment of the present invention.

FIG. 10 is a side view showing a main part of a conventional example.

FIG. 11 is a measurement comparison chart of the present invention and a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wrapping device 20 ... Wrapping tape 30 ... Press element 31 ... Press holding body 32 ... Base body 33 ... Elastic body 50 ... Wrapping tape guide mechanism 60 ... Tension holding mechanism 70 ... Supply mechanism

Claims (1)

[Claims] 1. A lapping apparatus for simultaneously polishing a work surface on the outer periphery of a work, which is rotatably and reversibly supported and capable of axial vibration, and is supported by a holder facing the work surface. A pressing element and a wrapping tape that is pressed against the surface to be processed by pressing the back surface of the pressing element, the pressing element is welded with diamond powder on the surface of the head facing the processing surface, and the holding A lapping apparatus comprising: a base body fitted and supported so as to be capable of advancing and retracting to and from a body; and an elastic body embedded in a back portion of the base body and elastically contacting the holding body.