JPS62152671A - Small shaft with precision finish surface and precision surface finishing method and its machine - Google Patents

Abstract

PURPOSE:To make it possible to machine the circumference of a small shaft so as to have a precision finish surface and to transfer a tape with the small shaft without giving any damage by compressively interposing a small shaft between two feed rollers and a small burnishing roller. CONSTITUTION:When feed rollers 2 are rotated, a small shaft 1 having a diameter of 2.5mm or less which is placed between a pair of feed rollers 2, 2 rotates. With this rotation, a burnishing roller is also rotated. The projections of the small shaft 1 for tape guide are crushed with the burnishing roller 4 to machine the circumference of the small shaft 1 so as to have a precision finish surface. The damage of a tape guided with the small shaft can be prevented.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention provides a small diameter steel with precision surface finishing. Small-diameter shafts for tape guides used in devices for recording and reproducing 8 voices or images on tape, and their accessories, etc., or said devices and their accessories. Small diameter shafts used in rotating bodies used in products or drive fIJ mechanisms, especially diameter 2
．． For shafts of 5 mm or less, we can provide shafts with an excellent precision surface finish that does not leave any scratches on the tape or bearings, and does not cause play due to initial wear after being inserted into the bearings, etc., at a low price. The present invention relates to a small-diameter shifter having such a precision surface finish, a precision surface finish method thereof, and an apparatus thereof.

[Technical background of the invention and its problems] A small-diameter shaft and a rotary body or drive for a tape guide, which have been conventionally used in devices for recording and reproducing audio or video on tape, and their accessories, etc. The small diameter shaft used in the fi1 mechanism and the like is made of a material v1 having corrosion resistance and wear resistance, such as stainless steel.

Therefore, when polishing the peripheral surface to prevent scratches on tapes, bearings, etc., since stainless steel is a sticky and difficult-to-cut material, a peeling phenomenon occurs as shown in Figure 12 (a). When observed with a roughness measuring machine, sharp image areas 31 were formed on the surface, which caused excessive scratches on the tape and bearings, making it unsatisfactory for use. Furthermore, even if superfinishing is performed to precisely finish the surface to a mirror-like surface, stainless steel is sticky as described above, so a small but sharp image portion 31 may be formed as shown in FIG. 12 (b). There was a drawback that a galling phenomenon occurred.

Furthermore, it was thought that most of the scratches on the tape were caused by dust, etc., mainly when the tape was in contact with a playback head, etc., or when the tape was being fed by the tape running shaft and pinch roller. .

Therefore, the small diameter shaft 1 for each tape guide in the cassette C in which the tape shown in FIG. 10 is wound and held.
The small-diameter shaft 1 in the recording/reproducing device S, etc., was not given much importance, and it was thought that it would be sufficient if the surface was simply ω1 polished, or even if it was precise, it was super finished.

However, as mentioned above, there is a drawback that the polished or super-finished surface of the small diameter shaft 1 may be scratched by contact with the tape T. If used in a playback device, the tape TS9 would be scratched. Therefore, in order to prevent fNJt scratches on the tape T, the quality of finishing of these small diameter shafts has become a major factor and has been closely focused on.

In addition, as shown in Figure 11, various small diameter shirts used in capstan shafts for video and audio tape drives and OA IN devices require very high precision, and their installation is difficult. () also requires high precision.

Therefore, if a shaft 1 that has been surface-finished using the 01 polishing or super finishing described above is used, the small-diameter shaft 1 has an image portion 31 on the circumferential surface, so the small-diameter shaft 1 is connected to the bearing 3 of the motor M. When inserted into the machine, this image part 31 wears out quickly, so-called initial wear occurs, and looseness occurs after use. It has a disadvantage that it cannot be used as a capstan shaft for driving video or audio tapes such as 1000, or as various small diameter shafts 1 used in 0△ equipment.

Therefore, in order to precisely finish the circumferential surface of the small-diameter shaft 1, in addition to the polishing method and super-finishing method described above, a rolling machine method, a lapping machine method, a polishing method, a lapping tape polishing method, a barrel method, a puff polishing method, etc. are used. Finishing experiments were carried out, but as shown below, satisfactory results could not be obtained by any of the methods.

In other words, the rolling machine method, which uses a rolling machine to finish the surface, has the disadvantage that the finish of the circumferential surface of the small diameter shaft deteriorates due to contact between the small diameter shaft and the supporting blade in the rolling machine. was there.

The lapping machine method, which uses a lapping machine to finish the finish, or the polishing method, which uses a polisher to finish the finish, is very laborious and takes a long processing time, and is labor-intensive due to poor workability. There were drawbacks that led to increased costs.

In addition, the lapping polishing method and the puff polishing method have disadvantages in that they have poor workability and require a lot of manpower, take a long processing time, and have poor finishing accuracy.

Furthermore, the barrel method, in which finishing is carried out by barrel polishing, has the disadvantage that small-diameter shafts are left with dents and scratches, bending occurs, and the overall finish is poor.

Therefore, if the shaft surface after polishing is finished with roller burnishing, the sharp image part 3 on the shaft surface
It was found that since the tape No. 1 was crushed to become a smooth surface, the surface of the tape was not scratched, and the initial abrasion described above did not occur.

However, in this roller burnish finishing, as shown in FIG.
A burnishing roll 34 is arranged on the opposite side of the feed roll 32, 32 to this shaft material 33, and this burnishing roll 34 is further pressed by two pressure rolls 35, 35. This vanishing roll 34
is pressed against the shaft material 33, and the two feed rolls 32 and 32 are rotated in the same direction and at the same speed, so that the shaft material 33, the burnishing roll 34, and the pressing rollers 35, 35 are rotated in conjunction with each other. The white part on the surface of the shaft material 33 is crushed to give a precision finish.

Therefore, if the diameter of the shaft material 33 is large, there is no equivalent problem, but as the diameter of the shaft material 33 becomes smaller, the shaft material 33 is divided into two parts facing each other with a slight gap between them. The burnishing roll 34 is placed between the two press rolls 35
．． 35, so that if the diameter is less than 2.5 mm, the feed roll 32.32 will come into contact with the burnishing 11-rule 34 or the press roll 35.35, making pressure contact impossible. There was a drawback that it became. Therefore, since it is not possible to perform roller burnish finishing on the surface of a small diameter shaft, the small diameter shaft 1 for a guide used in a device for recording and reproducing audio or video on a tape T, its accessories, etc., or the device described above. Roller burnish finish is not used for the surface finish of the small diameter shaft 1 used in the rotating body or drive mechanism used in the rotor and its accessories, etc., and the appearance of the small diameter shaft 1 with an excellent surface finish. , and the development of a finishing method and apparatus for the same.

[Object of the Invention] In view of the above-mentioned points, the present invention mainly relates to a small-diameter shaft or A rotating body used in the above device and its accessories, or a small diameter shaft used in the drive 1aMA, especially a diameter 2
．． We are able to provide shafts of 5 ffllll or less at low cost that have a smooth precision surface finish that does not leave any scratches on the tape or bearings, and does not cause initial wear when inserted into the bearings. It was created with the purpose of

[Summary of the Invention 1 In order to achieve the above-mentioned object, a small diameter shaft with a precision surface finish according to the present invention is used as a tape guide used in a device for recording and reproducing audio or video on a tape, and its accessories, etc. or small-diameter shafts used in rotating bodies and drive mechanisms used in the above-mentioned devices and their accessories, with a diameter of 2.5 mm or less and with corrosion and wear resistance comparable to that of stainless steel. 2 made of material and arranged to face each other with a gap between the two
It has a circumferential surface that has been given a precision surface finish by being sandwiched and brought into ffE contact while rotating in conjunction with a feed roll and a small-diameter burnishing roll that is pivotally supported on the thinner end of the thin press arm. In particular, the precision surface finishing method involves pre-polishing the circumferential surface of a shaft material with a diameter of 2.5 mm or less made of a corrosion-resistant material such as stainless steel, and then polishing the shaft material. , placed between two feed rolls that are arranged to face each other with a slight gap between them, and moved in the axial direction of the feed rolls while rotating, so that the shaft material is coated on the circumferential surface of the shaft material.
A small-diameter burnishing roll rotatably supported by the thinner end of the thin press arm is pressed from the opposite side of the feed roll, and the burnishing roll is rotated in conjunction with the small-diameter shaft material by the rotation of the feed roll. The purpose of this precision surface finishing device is to burnish the circumferential surface of the small-diameter shaft material using the circumferential surface of the burnishing roll when the small-diameter shaft material and the burnishing roll are pressed together. The feed rolls are arranged so that they face each other with a gap between them so that they can be driven and rotated in the same direction at the same speed. Set up a means of movement to move in the direction
), a burnishing roll that is rotatably supported by the thinner end of the thin pressing arm and that rotates in conjunction with the feed roll to press against the circumferential surface of the shaft material is placed in a direction opposite to the feed roll with respect to the shaft material. This is due to the fact that it was arranged in

[Embodiments of the Invention] The present invention will be described in detail below with reference to the drawings.

That is, the reference numeral 1 shown in FIG. 1 is a small-diameter shaft 1 as a guide shaft, which is installed in a cassette C in which, for example, a tape T is wound and held, and is used for guiding the tape T. be.

This small diameter shaft 1 is made of stainless steel having corrosion resistance and 1γ wear resistance, and has a diameter of 2.5 mm or less. The circumferential surface of this small-diameter shaft 1 is precision-finished by roller burnishing.

The roller burnish finishing method that applies this precision surface finish first polishes the shaft material U1 in advance, and then polishes the small diameter shaft 1.
Form it. Then, as shown in FIG. 2, this small diameter shaft 1 is placed between two feed rolls 2.2 which are arranged to face each other with a slight gap therebetween.

Next, a pressing arm 3 is arranged on the opposite side of the feed roll 2.2 with respect to the small diameter shaft 1.

As shown in FIG. 4, this beating force 7-m 3 is thin, and its front end is further tapered to serve as attachment parts 5, 5 for the burnishing rolls 4. When viewed from the side, this mounting portion 5.5 has an acute angle and is tapered to a point, and when viewed from the front, it has a mouth-shaped groove shape, and the burnishing roll 4 rotates within this groove to the extent that there is no play. Be as pivoted as possible.

As shown in FIGS. 6 and 9, this burnishing roll 4 is formed so that both end portions of a substantially cylindrical shape are tapered into a conical shape to form a tapered shaft support 6a as a shaft support 6, and an intermediate portion is formed to have a tapered shaft support 6a. The pressure contact surface 7 is made of a cylindrical peripheral surface. The pressure contact surface 7 has a tapered part 8 formed on the circumferential surface of one end side with a large radius so that the diameter gradually becomes smaller as it goes outward, and the other part is a straight circumferential surface. It's Toshide.

The burnishing roll 4 is pivoted to the mounting portion 5.5 by forming a tapered hole with the same inclination as the shaft support 6 in the inner wall of the groove of the mounting portion 5.5, as shown in FIG. A convex shaft support 6 is brought into surface contact with this hole to be rotatable.

Therefore, the burnishing roll 4, which is pivotally supported by the mounting portion 5.5 in this manner, is arranged at a position where the burnishing roll 4 is pressed against the small diameter shaft 1 using the mounting portion 5.5. Then, when the feed rolls 2, 2 are driven to rotate, the small diameter shaft 1 placed between the feed rolls 2.2 rotates along with the rotation of the feed rolls 2.2. The burnishing roll 4 also rotates in conjunction to apply roller burnishing and burrs.

Polished small diameter shaft 1 before burnished finish
Although the surface of the sheet has irregularities as shown in FIG. 12(A), the white portion 31 is crushed by the burnishing roll 4, so the white portion 31 on the surface is completely eliminated and the white portion 31 is crushed. Since the concave portion is also slightly filled in, the smooth surface 2 is
The proportion of number 4 becomes very large, and tape T is used when using it.
Good guidance can be performed without damaging the
It is possible to form a small-diameter shifter 1 having a circumferential surface with an excellent precision surface finish that does not cause initial wear after insertion.

Moreover, since a precision surface finish as a roller burnish finish is applied by press-contacting the small-diameter burnishing roll 4 pivotally supported by the press arm 3 to the small-diameter shaft 1 as described above, the diameter of the small-diameter shaft 1 is 2.5 mm. Even if the thickness is 5 mm or less, the feed roll 32, 32 and the venishing roll 34 or the press roll 35, 35, etc. in the conventional roller burnish finishing as shown in FIG. 14 will not come into contact and become impossible to process. Precision surface finishing can be applied.

In this case, as shown in FIG. 4, the width of the attachment part 5.5 of the press arm 3 may be formed in advance to a width that allows the burnishing roll 4 to be pivoted without play. Also, the fifth
As shown in the figure, the press arm 3 may be formed so that the adjusting body 9 can be adjusted and fixed as appropriate with a screw 10, and the burnishing roll 4 can be rotatably supported without play.

Then, as shown in FIG. 6, the pivot of the pressing arm 3 is
The shaft support 6 may be a conically pointed shaft support, but as shown in FIG. On the contrary, it may be pivoted by a concave portion as a tapered hole.

Historically, as shown in FIG. 8, the rotation of the burnishing roll 4 is greatly improved when the tapered holes are supported by a ball 12 made of metal or hard material. That is, by supporting the shaft in this manner, it becomes possible to provide a shaft support with extremely high strength. Further, the taper is formed at an angle of 50° to 70″, preferably 60°, and when the angle is set at 60°, a shaft support with the highest strength can be obtained.

Further, the mounting parts 5, 5 of the pressing arm 3, the burnishing roll 4, the pivot center 11, and the ball 12's may be made of high-hardness hardened steel, a bearing alloy material, a cemented carbide, a ceramic material, or the like. When used in combination, it becomes extremely superior in terms of wear resistance. Furthermore, the pressing arm 3
mounting parts 5, 5, burnishing roll 4, pivot center 1
If suitable hard plating treatment, nitriding treatment, hard coating treatment, etc. are applied to the surfaces of 1, ball 12, etc. depending on the compatibility with each other or with the material of the small diameter shirt 1-co, it will be more effective in terms of wear resistance. Demonstrate, and
Since they are compatible, an excellent precision surface finish can be obtained.

The apparatus for performing such precision surface finishing is constructed as follows.

That is, as shown in Fig. 3, 13 is a korekudai,
On this mounting base 13, a feed roll 2.2 is mounted and held, and a set of feed rolls 2.2 are mounted at a certain set angle with respect to the feed roll 2.2 so that they are tilted to opposite sides in a perpendicular direction. a feed roll set 14, a drive gear box 16 connected to the feed roll 2.2 via a universal joint 15 for driving the feed roll 2.2;
Pressing arm 3 supporting burnishing roll 4 shown in the figures etc.
, and the small diameter shaft 1 via its burnishing roll 4
A burnishing roll support device 17 is provided to provide the necessary pressure.

The feed roll 2.2 is formed entirely in a chain shape. That is, the center lines of the feed rolls 2.2 are inclined to opposite sides in a perpendicular direction to each other, and the entire feed rolls 2.2 are formed in a shape such that the line formed by the peripheral surfaces of the feed rolls 2.2 in the cross section becomes a hyperbola. Things are good. In this case, the feed wheels 2, 2 are arranged opposite to each other so that the movement locus of the small diameter shifter 1 is linear.

Although not shown, the feed roll 2.2 has a truncated conical shape, that is, a tapered shape. It may be formed as follows. In this case as well, the inclination angle of the feed rolls 2, 2 with respect to the horizontal plane is changed according to the taper angle, similar to the above-mentioned block-shaped feed rolls 2.2, and the passage path of the small diameter shift V-lift is made into a straight line or a gently curved line. It's Toshide.

Therefore, the feed rolls 2 and 2 are
．． A small diameter shifter 1 placed between 2 and 2 is placed between feed rolls 2 and 2.
A moving means is provided for moving the small diameter shaft 1 in the axial direction along the axis 2 while rotating. The means of transportation in this case is as follows. That is, the moving force in the axial direction obtained by the interlocking rotation of the small-diameter V-shift 1 between these feed rolls 2.2 is defined as the self-propelling force. In other words, it is tsuzumi-shaped or t
In the tapered feed roll 2.2, the self-propelling force of the small diameter shaft 1 obtained from the shape of these peripheral surfaces is used as a moving means.

On the other hand, the burnishing roll support device 17 moves up and down in conjunction with an internal pressing means, and has a burnishing roll bed 19 on the front surface to which a burnishing roll head 18 is fixed, and a pressurizing feed handle 20 on the top. and a pressing amount display means 21 that digitally displays the pressing amount of the burnishing roll 4 in conjunction with the rotation of the pressurizing feed handle 20.
and configure it.

The burnishing roll head 18 axially supports the burnishing roll 4 at the bottom via the press arm 3, and is provided with a fine adjustment movement means such as a screw to move the burnishing roll 4 by a small amount in the vertical direction. ''A fine adjustment dial 22 connected to this fine adjustment moving means is disposed in a part.

This fine adjustment movement means performs fine adjustment when a plurality of burnishing roll heads 18 are arranged in parallel on the burnishing roll bed 19, and it is used to align the burnishing roll heads 18 with each other or to change the height of the burnishing rolls 4. This makes it possible to gradually increase the amount of press. In addition, 2 in the figure
3 is a lock lever for fixing the pressurizing feed handle 20.

When feeding the material for the small-diameter shaft 1 to this device, if it is fed from the side of the burnishing part 8 of the burnishing roll 4, precision surface finishing can be carried out very smoothly.
It is something that can be done. In this case, the rotation direction of the feed rolls 2.2 may be left or right as long as the two feed rolls 2.2 rotate in the same direction and at the same speed. However, the direction of rotation and the direction of inclination of the feed roll 2.2 are appropriately set depending on the direction of movement of the small diameter shaft 1.

The small diameter shaft 1 which has been given a precision surface finish in this way can be used as a guide for the small diameter shaft 1.
In addition to completely eliminating scratches as shown in Figure 3 (B), small diameter shafts with precision surface finishing on the bearing portion are also available, as shown in Figure 13 (B). If 1 is inserted into something like the bearing 36, the initial wear that is the wear of the white part 31 shown in FIG. It is possible.

Also, the small diameter shaft 1 is connected to one burnishing O-
There are many smooth surfaces 24 because the processing is done by the
The circumferential surfaces of all processed small-diameter shafts 1 are uniformly finished. Moreover, since the small-diameter shaft 1 is passed through the small-diameter shaft 1 with the gap between the two foot rolls 2, 2 and one burnishing roll 4 set at a constant level, the uniformity of the cleanliness is very high. It is something that

[Effects of the Invention] According to the present invention configured as described above, a shaft for a tape guide used in a device for recording and reproducing audio or video on a tape T and its accessories, or a shaft for the tape guide used in the device and its accessories, etc. For small diameter shafts used in rotating bodies and drive mechanisms used in accessories, etc., the diameter is 2.5 mm.
Two feed rolls 2, 2 and a thin press arm 3, which are made of a corrosion-resistant and wear-resistant material such as stainless steel and are arranged to face each other with a slight gap between them, are made thinner. Since the small-diameter shaft 1 has a circumferential surface that has been given a precision surface finish by being pinched and pressed while rotating in conjunction with a small-diameter burnishing roll 4 that is pivotally supported at the tip, the tape T is When used as a guide small diameter shaft 11 fl-1, there is no white portion 31 on the surface of the small diameter shaft 1 and the tape T will not be scratched because of the roller burnish finish. Further, since there is no initial wear as described above when inserting the bearing into the bearing 36''S, it is possible to prevent looseness from occurring after insertion and to improve assembly accuracy.

Such a small-diameter shaft 1 is made by polishing the circumferential surface of a shaft material having a diameter of 2.5 mm or less and made of a corrosion-resistant and wear-resistant material such as stainless steel.
Thereafter, this shaft material is placed between two feed rolls 2.2 that are arranged to face each other with a slight gap between them, and is moved in the axial direction of the feed rolls 2.2 while rotating. On the other hand, a small diameter burnishing roll 4 rotatably supported by the narrower end of the bent-shaped pressing arm 3 is pressed against the circumferential surface of the roll from the opposite side of the feed rolls 2, 2, and the feed roll 2. 2 rotates the burnishing roll 4 through the small-diameter shaft material, and at this time, when the small-diameter shaft material and the burnishing D-rule 4 are pressed together, the circumferential surface of the burnishing roll 4 burnishes the circumferential surface of the small-diameter shaft 17. In conventional roller burnishing, the feed roll 32, 32 and the burnishing roll 3 are
4 or press rolls 35, 35, it was impossible to process a small diameter shaft 1 with a diameter of approximately 2.5 mm or less, but by forming such a press arm 3 and burnishing roll 4, a diameter of 2. .5mm or less small diameter shaft 1
Roller Vanilla Sea L finish is now possible. Moreover, if the small diameter shaft 1 is placed one after another between the feed rolls 2 and 2, the roller burnishing process can be performed continuously.
It is possible to automatically process a small diameter shaft 1 with a uniform circumferential surface and uniform dimensional accuracy.

Moreover, the apparatus for performing this precision surface finishing method is also provided with two feed rolls 2, 2 facing each other with a slight gap between them so that they can both be driven and rotated in the same direction at the same speed. 2 includes a feed roll 2.
A moving means is provided to move the shaft material placed between 2.2 and 1g processed on the circumferential surface in the axial direction along the feed roll 2.2, and is rotatable at the thinner tip of the book-shaped pressing arm 3. A burnishing roll 4 which is pivotally supported by the feed roll 2.2 and rotates in conjunction with the feed roll 2.2 to press against the circumferential surface of the shaft material is arranged in a direction opposite to the feed rolls 2, 2 with respect to the shaft material. Therefore, the structure is not complicated, so there are few failures, and it can be provided at a low price. By connecting a simple shaft material supply bag, it is easy to achieve complete automation, and it does not require manpower, so the small diameter shaft The cost reduction of precision surface finishing can be avoided.

Moreover, the circumferential surface of the small-diameter shaft 1 formed in this way is pressed by a smooth circumferential surface of a roll to smooth out minute protrusions on the surface of the small-diameter shaft 1, unlike the method of polishing or superfinishing. It is formed by rolling. Therefore, the finished machined surface has a cross-sectional shape in which the smooth surface 24 accounts for a very large proportion, as shown in FIG. 12(c). This finished smooth surface 24 becomes optimal as a circular surface for a tape guide.

That is, since the circumferential surface formed in this way is a combination of the smooth surface 24 and the concave portion, the adhesion of the tape can be weakened, and the smoothness l1fl'i24 can prevent the tape from being damaged. It is from.

Furthermore, the surface hardness of this peripheral surface increases through work hardening, and durability can also be improved.

However, since the machined surface undergoes plastic deformation similar to that of one rolled at room temperature, the crystal grains on the surface become finer, unlike those inside, and are subjected to shear deformation in the direction of roll finishing. As a result, the surface becomes a fibrous structure with compressive residual stress and a microstructure with work hardening, which can increase the surface hardness.

As explained above, according to the present invention, it is possible to smooth the circumferential surface of a small diameter shaft with a diameter of 25 mm or less, and furthermore, the durability of the machined surface can be improved by work hardening, and furthermore, continuous machining is possible. The small diameter shaft that has been processed is ideal for guides as it does not damage tapes and bearings, and it also does not cause initial wear after being inserted into bearings, making it easy to assemble and process. It has various excellent effects, such as being able to provide excellent accuracy, and being able to provide products that are uniform and excellent in consistency at a low cost.

[Brief explanation of drawings]

Figures 1 to 9 show embodiments of this invention.
Figure 1 is an enlarged perspective view of the installed small diameter shaft, Figure 2 is a side sectional view of the main part of the precision surface finishing device, Figure 3 is a front view of the same, and Figure 4 is a partially cutaway perspective view of the press arm. Figure 5 is an exploded perspective view of an embodiment of the press arm, Figure 6 is a sectional view of the main part showing the rotary support state of the burnishing roll, and Figures 7 and 8 are the rotary support state of the burnishing roll. 9 is a front view of a burnishing roll, FIG. 10 is a plan sectional view showing an example of using a small diameter shaft, and FIG. 11 is an example of using a small diameter shaft. Figure 12 is a waveform diagram of the surface roughness measurement of each scale's surface-finished small-diameter shaft, and Figure 13 is a diagram showing the state of use of the surface-finished small-diameter shaft. FIG. 14 is a side sectional view of a main part of a conventional roller burnish finishing device. S...Recording/reproducing device, C...Cassette, ■...Tape, M...Motor, 1...Small diameter shaft, 2...Feed roll, 3...
... Pressing arm, 4... Vanishing roll, 5...
Take A" part, 6... Pivot support, 6a... Pivot support surface, 7...
- Pressure contact surface, 8... Moving portion, 9... Adjustment body, 10
...Screw, 11...Spindle center, 12...Ball, 13...Mounting base, 1/! ... Feed roll set, 15... Universal joint, 16... Drive gear P box, 17... Burnishing roll support device, 18...
Burnishing roll head, 19... Burnishing roll bed, 20... Pressure feed handle, 21... Pressing amount display means, 22... Fine adjustment dial, 23...
Lock lever 124...smooth surface, 31...white part,
32...Feed roll, 33...Shaft, 34
... Burnishing roll, 35 ... Press roll, 36
···bearing. Patent applicant: Sanwa Needle Bearing Co., Ltd. 1 Figure 11 Figure 14 Figure 10 Section 2 Figure 121 (B) No. 13
Figure) (B) (
ZX) 9th ff? j

Claims (1)

[Claims] 1. A shaft for a tape guide used in a device for recording and reproducing audio or video on a tape and its accessories, or a rotating shaft used in the device and its accessories, etc. In small diameter shafts used in bodies and drive mechanisms,
It has a diameter of 2.5 mm or less and is made of a corrosion-resistant and wear-resistant material such as stainless steel, and is composed of two feed rolls and a thin press arm, which are arranged to face each other with a slight gap between them. A small-diameter shaft with a precision surface finish, characterized in that the circumferential surface has a precision surface finish applied by being sandwiched and pressed together while rotating in conjunction with a small-diameter burnishing roll that is pivotally supported at the tip of the shaft. . 2. The circumferential surface of a shaft material with a diameter of 2.5 mm or less made of a corrosion-resistant and wear-resistant material such as stainless steel is polished in advance, and then this shaft material is placed facing each other with a slight gap between them. It is placed between two feed rolls arranged so that it rotates on its own axis and moves in the axial direction of the feed rolls, and is attached to the thinner end of the thin press arm on the circumference of the shaft material so that it can rotate freely. A small-diameter burnishing roll, which is pivotally supported by the feed roll, is pressed from the opposite side of the feed roll, and the burnishing roll is rotated in conjunction with the small-diameter shaft material by the rotation of the feed roll, and at this time, when the small-diameter shaft material and the burnishing roll are pressed together, , a precision surface finishing method for a small-diameter shaft, characterized in that the circumferential surface of the small-diameter shaft is burnished by the circumferential surface of a burnishing roll. 3. The feed rolls are made so that their center lines are inclined to opposite sides in a perpendicular direction to each other, so that the line formed by the peripheral surface of the feed roll in the cross section becomes a hyperbola, so that the movement locus of the shaft material is A precision surface finishing method for a small diameter shaft according to claim 2, wherein the shaft is formed so as to be in a straight line. 4. The burnishing roll is configured such that the end of the shaft material on the cutting side gradually becomes smaller in diameter as it goes outward to facilitate the cutting of the shaft material in the cutting process in continuous machining. Precision surface finishing method for small diameter shafts. 5. The burnishing roll is supported by a shaft support surface formed by a tapered surface, and the burnishing roll side is convex and the shaft support side is concave, or the burnishing roll side is concave and the shaft support is concave. 3. A precision surface finishing method for a small-diameter shaft according to claim 2, which is carried out by using a combination of convex sides, or concave sides, and arranging metal or hard material balls between the concave tapered surfaces. 6. The precision surface finishing method for a small diameter shaft according to claim 5, wherein the taper of the shaft supporting surface is approximately 60°. 7. Two feed rolls are provided so as to face each other with a slight gap between them so that they can both be driven and rotated in the same direction at the same speed. A moving means for moving the shaft material in the axial direction along the feed roll is provided, and the shaft material is rotatably supported by the thinner end of the thin pressing arm, and rotates in conjunction with the feed roll to move the shaft material in the axial direction. A precision surface finishing device for small diameter shafts, characterized in that a burnishing roll that is brought into pressure contact with the shaft material is arranged in the opposite direction to the feed roll. 8. The means for moving the shaft material is such that the center lines of the feed rolls are inclined to opposite sides in a perpendicular direction to each other, and the whole is shaped like a chain so that the line formed by the peripheral surface of the feed roll in the cross section becomes a hyperbola. 8. The precision surface finishing device for a small diameter shaft according to claim 7, wherein the shaft material is formed so that the movement locus is on a straight line. 9. The burnishing roll is narrowed so that the end of the shaft material on the cutting side gradually becomes smaller in diameter as it goes outward to facilitate the cutting of the shaft material in the cutting process in continuous machining. Precision surface finishing equipment for small diameter shafts. 10. The burnishing roll is supported by a shaft support surface formed by a tapered surface, and the burnishing roll side is convex and the shaft support side is concave, or the burnishing roll side is concave and the shaft support side is concave. 8. A precision surface finishing device for a small diameter shaft according to claim 7, wherein the surface finishing device is a combination of a convex shape, or a concave shape, and a metal or hard material ball arranged between the concave tapered surfaces. 11. The precision surface finishing device for a small diameter shaft according to claim 10, wherein the shaft support surface has a taper of approximately 60 degrees.