JP2536294Y2 - Roller burnishing equipment for thin cylindrical materials - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a drum for a copying machine and a VT.
The outer cylindrical surface of a thin-walled cylindrical member, for which roller burnishing was previously impossible due to insufficient strength against the force to press the surface to be processed, such as an R guide roller, can be mirror-polished in one pass by roller burnishing. The present invention relates to a roller burnishing device for a thin cylindrical material.

[0002]

2. Description of the Related Art In roller burnishing, a hard small-diameter roller is pressed against the surface of a workpiece to be rolled, and fine irregularities on the surface such as a blade trace during cutting are crushed (plastically deformed). This is a processing method for forming a flat mirror surface. According to the roller burnishing process, in addition to the fact that a sophisticated mirror surface of 0.1 to 0.8 S can be obtained by a relatively simple device configuration and easy work management, the surface layer of the workpiece is work hardened, Since residual compressive stress is generated on the surface layer of the workpiece, a finished surface having excellent durability, abrasion resistance, and corrosion resistance can be obtained. Roller burnishing is widely applied as a finishing process in various applications such as an inner cylindrical surface of a cylinder of an internal combustion engine, a bearing sliding surface of a motor shaft, a valve seat of a valve, and a sealing surface of a vacuum vessel.

[0003] As one of practical roller burnishing apparatuses, there is known an apparatus of a type in which a cylindrical workpiece is automatically fed by a roller itself in the axial direction without a chuck, and the cylindrical surface is subjected to roller burnishing in one pass. Have been. This is an apparatus in which the "balls arranged along the outer periphery of the workpiece" in the "outer diameter finishing apparatus" of Japanese Utility Model Laid-Open No. 3-11557 are replaced with "rollers having a predetermined pitch angle". That is, a roller arranged at a predetermined pitch angle on a circumference along a surface to be processed, a mandrel head having a roller guide surface formed thereon, and a roller bound axially and circumferentially on the guide surface. a frame member which consists of a drive means for relatively rotating the frame member relative to the mandrel head, the roll space formed inside the roller restraining the outer mandrel head,
To accommodate workpieces slightly larger than the roller inscribed circle
Force the mandrel head and frame member to rotate relative to each other.

[0004] At this time, the workpiece that keeps line contact with the roller is forcibly fed in the axial direction by the pitch angle, that is, the inclination angle between the workpiece axis and the roller axis in the tangential direction, and the cylindrical surface is continuously rolled. Burnished. In other words, due to the relative rotation of the mandrel head and the frame member, the rollers roll on the guide surface to perform planetary motion, and roll on the cylindrical surface of the workpiece to move the workpiece one after another in the axial direction. And automatically feed at a constant speed. Mandrel
The plurality of rollers backed up by the head roll one after another spirally with respect to the cylindrical surface of the workpiece to perform roller burnishing.

Here, actually, frusto-conical rollers whose diameter is reduced toward the rear side are employed, and these rollers are also conical rollers and rollers whose diameter is reduced toward the rear side. They are arranged with a predetermined pitch angle on the guide surface to form a roll space in the form of a convoluted surface (a hyperboloid of revolution). This combination of conical roller and conical guide surface, mandrel
To allow the adjustment of the diameter of the roll space (roll inscribed circle) by axial movement of the frame members relative to Le head,
Further, the roll space in the form of a pinched surface forms a gradual retreat of the roll from the surface to be processed in the rear half portion of the roller, so that no spiral scratch is left on the finished surface.

[0006] In such a roller burnishing apparatus,
Since the processing pressure of the rollers can be offset by the rollers facing each other and the round bar-shaped workpiece can be processed automatically and efficiently without chucking, after the cylindrical surface of the elongated metal round bar is mirror-finished, It is extremely advantageous when producing a large number of shafts with simple dimensions, such as guide shafts for OA equipment and tape guide rods for VTRs, which are manufactured in short cuts.
It is a highly productive device.

Further, since no special mechanism for chucking, positioning and feeding of the workpiece is required, the structure of the apparatus can be simplified and the size can be easily reduced. In addition, a short row
Can be used to burnish unlimitedly long workpieces uniformly, and the workpieces do not need gripping for chucks, so the entire length of the workpieces can be used without waste, There is no excessive force such as twisting.

[0008]

However, such a roller burnishing apparatus is not suitable for processing the outer cylindrical surface of a thin cylindrical material such as a copying machine drum or a video guide roller. And it was. In such a roller burnishing apparatus, a processing pressure is applied to a roller by using a difference in diameter between a roller inscribed circle and a surface to be processed, whereas a thin cylindrical material is used for a roller. As a result, the shape is elastically deformed by a local pressing force from the outside, so that the processed surface escapes from the roller, and it is not possible to secure the processing pressure necessary for the plastic deformation of the surface irregularities.

However, if the diameter difference between the roller inscribed circle and the surface to be processed is increased in order to secure the processing pressure, unevenness of the burnishing effect occurs on the surface to be processed, and the finishing accuracy deteriorates, and at the same time, the thin cylindrical material itself is deformed. As a result, the roundness after processing is extremely deteriorated. Further, there has been a problem that the workpiece cannot smoothly enter the roll space, and the automatic feeding by the roll lead angle does not work well.

Therefore, a jig for backing up the cylindrical surface is inserted inside the thin cylindrical member, and the burner is subjected to roller burnishing by sandwiching the wall surface of the thin cylindrical member between the jig and the roller. However, if the roller and the jig are not accurately positioned across the wall, the roundness of the thin cylindrical material may be lost due to uneven surface plastic deformation, and the support mechanism of the jig is complicated. As a result, the advantages of such a roller burnishing device were reduced, for example, the device became large-scale, and smooth one-pass machining was not possible.

By the way, a copying machine drum expected to be processed by a roller burnishing apparatus has, for example, a diameter of 3 mm.
It is a thin cylindrical material made of aluminum having a thickness of 0 mm, a thickness of 1.5 mm, and a length of 300 mm, and its outer peripheral surface is mirror-finished to about R8. Conventional copying machine drums are finished by rough cutting the cylindrical surface of the drawn aluminum tube by ordinary machining, followed by mirror cutting using a diamond bite, or grinding and buffing. If processing can be performed with a one-pass type roller burnishing apparatus without a king, it is expected that the material, processing time and processing labor can be significantly reduced. However, actually, since the strength of the material is low in addition to the thin cylindrical material, the conventional roller burnishing apparatus cannot be applied as described above.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a thin cylindrical material.
For the outer cylindrical surface , it is possible to perform uniform roller burnishing by securing the processing pressure required for plastic deformation of surface irregularities without adversely affecting the roundness after processing, and the conventional easy and free one-pass processing It is an object of the present invention to provide a roller burnishing device that does not impair the image quality.

According to a first aspect of the present invention, there is provided a roller burnishing apparatus for a thin cylindrical material, comprising: a plurality of rollers arranged at a predetermined lead angle on a circumference along a processing surface of the thin cylindrical material; A roller burnishing apparatus comprising: a mandrel head having a surface formed thereon; a frame member for binding rollers in the axial direction and the circumferential direction on the guide surface; and driving means for rotating the frame member relative to the mandrel head . Wherein the outer cylindrical surface of the thin-walled cylindrical material is subjected to roller burnishing in an air-core state, and as the roller, the individual biasing load is lower than the elastic deformation strength of the thin-walled cylindrical material during processing. An odd number of small-diameter rollers, which roll by pressing the outer cylindrical surface substantially uniformly, are arranged at substantially equal intervals on the circumference.

According to a second aspect of the present invention, there is provided a roller burnishing apparatus for a thin-walled cylindrical material according to the first aspect of the present invention , wherein a radius of at least the maximum radius of the roller is formed at a shoulder portion of each of the rollers on the workpiece insertion side. It is.

[0015]

In the roller burnishing apparatus for a thin-walled cylindrical material according to the first aspect, similarly to the related art, the roller whose movement in the diametrical direction is restricted by the guide surface of the mandrel head and whose movement in the circumferential direction is restricted by the frame member, The outer cylindrical surface of the workpiece (thin cylindrical material) is rolled with the relative rotation of the mandrel head and the frame member, and the irregularities on the sample surface are crushed to form a mirror surface. At this time, the processing pressure acting on the surface to be processed is canceled by some of the rollers facing each other, and the workpiece is supported by the rollers and does not require special chucking. The roller forms a spiral trajectory determined by the lead angle with respect to the surface to be processed (thin cylindrical material). When the roller is fixed in the axial direction in the device, the workpiece is automatically fed in the axial direction. Is done.

In general, a reduction in the diameter of a roller causes a reduction in the life of the roller, and an increase in the number of rollers decreases the mandrel head.
Although higher processing accuracy is required for the guide surfaces, rollers, and frame members on the guide side, the present invention makes it possible to process thin-walled cylindrical materials. An odd number and a large number of rollers arranged at equal intervals press the outer cylindrical surface of the workpiece almost uniformly, narrow the deflection range of the cylindrical surface per roller, and reduce the cross section of the thin-walled cylindrical material. In addition to increasing the resistance to deformation, the amount of elastic deformation of the contact portion with the roller is minimized. Further, the odd number of rollers has two rollers opposed to the opposite side of one roller, and converges the disturbance of the pressure distribution generated in the cross section toward an even stable state. The small pitch angle and the large number of rollers increase the number of times the rollers pass through the unit surface to be processed, and reduce the amount of plastic deformation per time, that is, the processing pressure required for one roller.

When the number of rolls is small, the cylindrical surface pressed against the rolls from the periphery is depressed inward at the position of the roll and bulges outward at the intermediate position between the two rolls, so that the cross section is reduced. It becomes a state of wavy deformation, and the elastic deflection of the thin cylindrical member is reduced to a value required for burnishing.
Makes it impossible to increase the pressure on the contact surface. When the number of rolls is increased, the cylindrical surface whose swelling is suppressed by the rolls on both sides forms an arch against the central roll and resists it.
The pressure on the roll contact surface can be increased to a necessary and sufficient value. The required number of rollers depends on the diameter, thickness, and material of the cylinder, but more than 9 for an aluminum cylinder with a diameter of about 30 mm, and more than 11 for stable processing. Was confirmed. This is more than 50% more than 5 to 7 rollers in a normal roller burnishing apparatus for processing a cylindrical material having a diameter of about 30 mm.

The relationship between the diameter and the number of rolls is expressed by He.
The contact pressure calculated from the contact theory of rz is determined so that the entire workpiece is not deformed. When roll burnishing a cylindrical surface from the outside, the radius of the workpiece is r
₂ , the longitudinal elastic modulus is E ₂ , the Poisson's ratio is ν ₂ , the radius of the roll is r ₁ , the longitudinal elastic modulus is E ₁ , the Poisson's ratio is ν ₁ , the biasing load is P, If the equivalent radius ρ of the contact surface between the workpiece and the roll is defined as 1 / ρ = 1 / r ₁ + 1 / r ₂ , the maximum pressure P _{max on the} contact surface is obtained according to Herz's contact theory.
Is P _max = {P / πlρ) E ₁ E ₂ / [E ₁ (1-r ₂ ² ) + E ₂ (1-r ₁ ² )]} ^1/2 (1) In order for the contact surface to be plastically deformed by roller burnishing, the maximum pressure _Pmax must exceed the compressive strength of the material. (1) In the equation, when a constant maximum pressure P _max, the load P equivalent radius ρ is proportional, the equivalent radius ρ b - is the radius r ₁ and proportional Le.
Therefore, Russia - requires only a more Le radius r ₁ is less load P is also small. The number and diameter of the rolls are determined together with the calculation of the strength of the thin-walled cylinder that receives a load from the outside.

On the other hand, the above-mentioned resistance force forming an arch with respect to the roll does not act on the inner cylindrical surface of the workpiece, but the suppression force of the cross-sectional deformation caused by increasing the number of rolls is the same. To help increase the pressure on the contact surface. In other words, an odd number and a large number of rollers arranged at equal intervals exert a pressing force almost uniformly, thereby narrowing the deflection range of the cylindrical surface per one roller and minimizing the amount of elastic deformation of the contact portion. A small pitch angle and a large number of arranged rollers increase the number of times the rollers pass through the unit work surface and reduce the amount of plastic deformation per operation, that is, the urging load required for one roller I do. Small diameter rollers further reduce this biasing load, as described above.

In the roller burnishing apparatus for a thin-walled cylindrical material according to the second aspect of the present invention, the R formed at the shoulder portion of the roller on the workpiece insertion side is a bite between the roll space and the workpiece. To smooth out. In processing the outer cylindrical surface of the workpiece, a workpiece (particularly, a material having a diameter larger than the length) larger than the roll inscribed circle is inserted into the roll space surrounded by the roll. When the axis of the roll space and the axis of the workpiece are slightly tilted, the workpiece inserted obliquely swings, causing large irregularities with a pitch called "undulation" on the processing surface, May be deformed and the roundness after processing may be reduced. B
The R formed on the shoulder of the roller prevents the roll from sliding and the workpiece to prevent biting while the axis of the roll space does not coincide with the axis of the workpiece. Biting and roller burnishing are started when the axis and the axis of the workpiece coincide with each other and the roll pressing force reaches a maximum.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of a roller burnishing apparatus for a thin-walled cylindrical material according to the embodiment, and FIG. 2 is an explanatory view of a roller arrangement in the roller burnishing apparatus for a thin-walled cylindrical material of FIG.
FIG. 1 shows a processing head portion of a roller burnishing apparatus for processing an outer cylindrical surface, with the upper half thereof being a cross section. 2A shows the front of the roller including the frame member, FIG. 2B shows the state of contact between the side of the workpiece and the roller, and FIG. 2C shows the shape of the roller. I have.

[0023] In FIG. 1, the mandrel header consisting of mutually fastened the thimbles 6 and the mandrel head 2 which
The screw is screwed into a screw 12 formed inside the flange 17, and rotates together with the adjust ring 11 with respect to the flange 17. The rotation is performed with a mandrel against the flange 17.
Although the axial position of the rel head is shifted, it can be fixed by the lock nut 13. The roller 1 whose diameter and axial position is restricted by the frame 3 is a mandrel
Eleven are arranged at equal intervals at a pitch angle of 30 degrees on a guide surface formed on the head .

The frame 3 is integrally fixed together with the stem 15, the guide 5, the pulley 19, and the U nut 20.
The frame 3 is held inside the flange 17 by a composite needle roller bearing 10, a bush 7, and an oil seal 18, and is axially fixed to the flange 17 by a thrust ring 9 and a stop ring 14. . The Teflon guide 4 is fitted inside the frame 3, and a screw hole 16 for fixing the entire machining head is formed in the flange 17.

In the thus configured roller burnishing apparatus for a thin-walled cylindrical material, the flange 17 is fixed to the apparatus, and the pulley 19 is connected to a prime mover (not shown) by a timing belt, so that the frame 3 is connected to the mandrel head 2 .
Is driven to rotate at about 400 rpm, and 1
A thin cylindrical material having an outer diameter slightly larger than the inscribed circle of one roller 1 is made to bite between the rollers 1 from the left in the figure. Thus, the roller 1 that rolls on the guide surface of the mandrel head 2 automatically feeds the thin cylindrical material to the right while forming a spiral burnishing trajectory on the outer cylindrical surface of the thin cylindrical material. The eleven rollers 1 overlap each other to form a mirror surface on the outer cylindrical surface of the thin cylindrical material.

If the combination of the diameters of the inscribed circles of the eleven rollers 1 with respect to the outer shape of the thin cylindrical member is inappropriate, the lock nut 13 is loosened and the adjust ring 11 is rotated to shift the screwing position of the screw 12. , Flange 17 and mandrel
.Axial positional relationship with the head 2 , ie, mandrel
The positional relationship between the frame 3 and the roller 1 with respect to the guide surface of the head 2 is changed by a required amount. In practice, the roller 1 has a narrow frustoconical shape on the left, a mandrel head 2
Has a narrow conical shape on the left side, and the movement of the positional relationship changes the diameter of the guide surface of the mandrel head 2 on which the rollers 1 roll, and the diameter of the inscribed circle of the eleven rollers 1 Scale up or down. The new positional relationship is fixed again by the lock nut 13.

In FIG. 2A, 11 rollers 1
Is housed in an opening formed through the frame 3 and is constrained in the diametrical direction (at least inward direction) and the axial direction, and the circumcircle of the eleven rollers 1 is attached to the mandrel head.
The inscribed circle forms a roll space with respect to the outer cylindrical surface of the thin cylindrical material.

In FIG. 2B, the roller 1 has a lead angle θ with respect to the thin cylindrical material W, that is, the thin cylindrical material W
And the inclination of the axis of the roller 1 are arranged at θ. Here, only one of the eleven rollers 1 is shown. The roller 1 rolls on the outer cylindrical surface of the thin cylindrical material W to form
The roll burnishing processing surface K is formed.

In FIG. 2 (c), the side of the roller 1 into which the thin cylindrical member W is inserted, that is, the shoulder 1a of the frusto-conical cone having a large diameter is larger than the maximum radius of the roller 1. R is formed. As a result, a clear ridge 1b is formed between the shoulder 1a and the rolling surface of the roller 1. Due to the radius of the shoulder 1a, even when the frame rotation speed is increased to 400 rpm, smooth and reliable biting between the roll space of the roller 1 and the thin cylindrical material W is achieved.

As a result of processing the copying machine drum using the roller burnishing apparatus for a thin-walled cylindrical material of the present embodiment, the processing time itself was reduced in comparison with the conventional mirror cutting using a diamond tool. In addition, since it was not necessary to perform troublesome attachment / detachment of the material or machining of the attachment / detachment, the total machining time was reduced to 1/10. As a result, the manufacturing cost of the copying machine drum, for which the mirror finishing cost was dominant, was reduced to one.
/ 3.

The roller burnishing apparatus for a thin-walled cylindrical material according to the present embodiment is basically a centerless type, and does not need to clamp and position the thin-walled cylindrical material. An easy and simple system configuration with high reliability is possible even if the supply mechanism of the cylindrical material is included.

[0032]

[Effects of the Invention] In the roller burnishing apparatus for thin-walled cylindrical materials of the present invention, the outer cylindrical surface of a thin-walled, relatively large-diameter thin-walled cylindrical material, such as a copying machine drum or a video guide roller, which has been difficult to process in the past. Without adversely affecting the roundness after processing, it is possible to secure the processing pressure necessary for plastic deformation of surface irregularities and perform uniform roller burnishing processing,
A mirror surface is obtained.

In the roller burnishing device for thin-walled cylindrical material of the present invention, a special chuck mechanism and a feeding mechanism for thin-walled cylindrical material are unnecessary as in the conventional case, and the material corresponding to the attachment / detachment of the material is saved. At the same time, the one-pass processing with high work efficiency which does not require the attaching / detaching operation is maintained as it is.

[Brief description of the drawings]

FIG. 1 is a schematic view of a roller burnishing apparatus for a thin-walled cylindrical material according to an embodiment.

FIG. 2 is an explanatory view of a roller arrangement in the roller burnishing device for a thin cylindrical member of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Roller 2 Mandrel head 3 Frame 4 Teflon guide 5 Guide 6 Thimble 7 Bush 9 Thrust ring 10 Composite needle roller bearing 11 Adjust ring 12 Screw 13 Lock nut 14 Stop ring 15 Stem 16 Screw hole 17 Flange 18 Oil seal 19 Pulley 20 U nut

Claims (2)

(57) [Scope of request for utility model registration] A plurality of rollers arranged at a predetermined lead angle on a circumference along a processing surface of a thin cylindrical material;
A mandrel head forming a guide surface of the roller,
A roller burnishing apparatus comprising: a frame member for binding rollers in the axial direction and the circumferential direction on the guide surface; and driving means for relatively rotating the frame member with respect to the mandrel head . Roller burnishing the outer cylindrical surface of the cylindrical material, wherein the roller substantially uniformly presses the outer cylindrical surface with an individual biasing load lower than the elastic deformation strength of the thin-walled cylindrical material during processing. A roller burnishing apparatus for a thin-walled cylindrical material, wherein an odd number of small-diameter rollers which roll by rolling are arranged at substantially equal intervals on the circumference. 2. A roller burnishing apparatus for a thin-walled cylindrical material according to claim 1, wherein an R having a radius equal to or greater than a maximum radius of the roller is formed at a shoulder portion of each roller on a workpiece insertion side. .