JPS63162156A - Roller burnishing method and device thereof - Google Patents

Abstract

PURPOSE:To perform burnishing on the outer periphery or a work efficiently without leaving indentations by pressing the work rotated around an axis at the finish start position on oblique finishing rollers, starting the roller processing, and relatively moving it under the pressed state. CONSTITUTION:When finishing rollers 18 are brought into contact with a work 14 being rotated by a work drive device, the first and second roller units 70, 71 are expanded against the energizing force of a pressing device 64 because the outer diameter of the work 14 is larger than the distance between both finishing rollers 18 when a stopper 65 hits it. At the same time, the pressing between the work 14 and the finishing rollers 18 is started, the finishing rollers 18 and backup rollers 20 start to be rotated by the rotation of the work 14, a feeding device 22 slowly continues to feed a roller holding device 16, thus the pressing position between the work 14 and rollers 18 is moved in the axial direction. Next, as the pressing position is moved, the roller processing is applied to the whole outer periphery of the large-diameter section of the work 14 to obtain the predetermined smooth surface.

Description

[Detailed Description of the Invention] The present invention relates to a technique for improving the surface roughness of the outer circumferential surface of a workpiece having a circular cross section, and particularly to a method of burnishing using a roller and a burnishing method thereof. The present invention relates to an apparatus suitable for implementation.

Conventionally, when it is necessary to finish the surface of a workpiece to a good surface roughness, lapping is performed on the workpiece after grinding with a whetstone or the like. This wrap finish is
A lapping agent is attached to the surface of the workpiece, and protrusions on the surface are scraped off by applying pressure and sliding it around. By appropriately changing processing conditions such as processing time, particle size of the lapping agent, and lapping liquid, the desired result can be achieved. This achieves machining accuracy of .

However, the surface of the workpiece by lapping is generally finished to follow the surface roughness after the pre-processing, that is, after the grinding process. If surface defects such as protrusions exist, it is difficult to correct them to a good smooth surface no matter how you change the processing conditions mentioned above and perform lapping. Furthermore, when used as an oil-tight surface with a soft seal such as an oil seal, the above-mentioned protrusions may scratch the inner peripheral surface of the oil seal that comes into sliding contact with the workpiece, causing abnormal wear. As a result, a problem arises in that oil leaks from between the workpiece and the oil seal.

Therefore, we investigated a method for smoothing even the defective surfaces as described above, and as a result, we tried the pole burnishing method instead of the lapping method. This pole burnishing method removes protrusions by bringing a rotatable carbide steel ball into point contact with the outer circumferential surface of a rotating workpiece and moving both relative to each other in the axial direction of the workpiece under appropriate pressure. It is used to flatten the finished surface by crushing it without causing any damage. As a result of the trial,
It was confirmed that by using this pole burnishing method, the outer peripheral surface of the workpiece could be machined with a surface roughness that was quite close to the ideal value.

However, finishing by this pole burnishing method has low processing efficiency and requires a lot of time for finishing because the area that can be processed by the steel ball contacting the outer peripheral surface of the workpiece at one time is small. Further, since the steel ball and the outer circumferential surface of the workpiece are pressed at one point, there is a problem that an impression of the steel ball may remain on the outer circumferential surface.

The present invention has been made in order to solve the above problems, and to provide a method for burnishing the outer peripheral surface of a workpiece with high processing efficiency and without leaving any impressions, and an apparatus suitable for carrying out the method. be.

In the roller burnishing method of the first invention, a workpiece with a circular cross section is rotated around its axis, a finishing roller having a smooth outer circumferential surface is diagonally intersected with the workpiece, and both are attached to the workpiece. Start pressing from the finishing start position determined above and move the workpiece and finishing roller relative to each other in a direction intersecting their axes within a plane parallel to their axes while rotating the finishing roller. This is a characteristic feature.

Further, the roller burnishing device of the second invention includes (a) a workpiece drive device that holds a workpiece and rotates it around its axis, and (b) a finishing roller and a backup roller having a larger diameter than the finishing roller. a roller mechanism capable of rotating while contacting each other on the outer peripheral surface, and holding a finishing roller in a state between the backup roller and the workpiece;
(The Cl roller mechanism and the workpiece drive device are moved relative to each other in a processing direction that is perpendicular to a plane parallel to the axes of the finishing roller and the workpiece, where the finishing roller and the workpiece intersect obliquely, and where they can contact each other on their outer peripheral surfaces. (e) a frame that supports the finishing roller in the desired state; It includes a feeding device that relatively moves the workpiece and the finishing roller in a direction intersecting the axes within a plane.

According to the present invention, the workpiece is rotated around the axis and is pressed at the finishing start position by the finishing roller obliquely intersecting the workpiece, and the roller application at this position is started.

Moreover, the two are moved relative to each other while maintaining this pressed state, and the pressing position of both is moved in the axial direction both on the workpiece and on the finishing roller, and finally the entire outer circumferential surface of the workpiece is covered. Smoothed by rolling.

In this way, the workpiece and the finishing roller come into contact with each other in an oblique state, so the area that can be processed with one contact is wider than in the case of the pole burnishing method described above. Therefore, the finishing efficiency is increased and the machining time is shortened, and at the same time, the possibility of leaving impressions on the finished surface is reduced. In addition, the contact surface between the workpiece and the finishing roller is sized to provide enough contact pressure to smooth out protrusions without increasing the pressing force of both to an extremely large extent. can be effectively avoided from remaining. Therefore, in the case of the above-mentioned workpiece and oil seal, the oil seal is not scratched and worn, its wear resistance is improved, and the possibility of early oil leakage is reduced.

Moreover, work hardening occurs in the surface layer of the workpiece due to the pressure of the finishing roller, and the mechanical properties such as fatigue strength of the surface layer are improved.

Furthermore, if the roller mechanism is equipped with a pair of finishing rollers, the forces applied to the workpiece from the roller mechanism in opposite directions cancel each other out, making the device that supports the workpiece less rigid. can, and
Since both sides of the outer peripheral surface of the workpiece are machined simultaneously, the time required for finishing can be further shortened, and an increase in manufacturing costs due to improvement of surface roughness can be suppressed.

Further, if the frame supports the finishing roller via an elastic support means, the finishing roller can be displaced according to the center height of the workpiece. Therefore, the workpiece is not affected by the dimensional accuracy of the frame, and even eccentric workpieces will not be subjected to uneven roller pressure.
It can always be finished with good surface roughness.

Furthermore, if this elastic support means is provided with an adjustment means, it becomes easy to adjust the center height of the finishing roller relative to the workpiece.

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

FIG. 1 is a plan view showing a roller burnishing device 10 according to an embodiment of the present invention. Reference numeral 12 denotes a workpiece drive device, which holds the workpiece 14 to be surface-finished and gives it rotational movement around its axis.

Adjacent to this workpiece drive device 12 is a roller holding device 16.
is installed. This roller holding device 16 is
4, a finishing roller 18 and a backup roller 20 are provided which intersect obliquely at an angle α0, and are supported by a moving table 24 of a feeding device 22 and moved in the feeding direction (direction of arrow A). This feeding direction is along a plane parallel to the two axes of the workpiece 14 and the finishing roller 18,
Furthermore, the direction is perpendicular to the axis of the finishing roller 18. The work drive device 12 and the feed device 22 are supported by a main frame 26.

The workpiece 14 has a large diameter portion 30 and a small diameter portion 32 formed therein. The outer peripheral surface of this large diameter portion 30 is a finished surface 34 to which surface finishing is applied.

The workpiece drive device 12 has a headstock 40 and a spindle 42 facing the headstock 40 disposed on a bed 44 . A pair of centers 48 and 50 are disposed at the end of the spindle 46 of the head stock 40 and the center support 42, and both centers 48 and 50 support both ends of the workpiece 14. Furthermore, a rotating plate 52 is also attached to the end of the main shaft 46, and this rotating plate 52
is rotated by a drive device 54. This turning plate 52
One end of the rotary ring 56 attached to the end of the small diameter portion 32 of the workpiece 14 is engaged, and the rotation of the drive device 54 is transmitted to the workpiece 14. On the other hand, the Shinshin stand 42 can be moved in the direction toward and away from the main shaft 46, and the distance between the two centers can be adjusted.

As shown in FIG. 2, the roller holding device 16 includes a roller mechanism 60 that rotatably holds the finishing roller 18 and the backup roller 20, a support member 62, a pressing device 64, a stopper 65, and an unclamping device. 66 and
It is configured by a mounting base 68.

The roller mechanism 60 includes first and second roller portions 70.7 that hold a pair of finishing rollers 18 and a backup roller 20 at opposing positions with the workpiece 14 in between.
1 is formed, and a pair of first and second arms 72.73 are connected to both roller portions 70.71. In this embodiment, the pressing force direction is the direction in which the finishing rollers 18 sandwiching the work 14 approach each other.

In the first roller section 70, a housing 74 supports the outer peripheral surfaces of the finishing roller 18 and the backup roller 20. Furthermore, as shown in FIG. 3, a pair of side frames 75.7 are provided at both ends of the housing 74.
6 are arranged with predetermined gaps between them. The finishing roller 18 and the backup roller 20 are slidably supported by the housing 74, and their axial movement is restricted by the side frames 75, 76.

A roller groove 78 and a through hole 80 parallel to the roller groove 78 are formed in the housing 74 . As shown in FIG. 2, the roller groove 78 has a diameter slightly larger than that of the finishing roller 18, and has a depth that allows the contact portion T of the finishing roller 18 with the workpiece 14 to be exposed from the housing 74. There is. Furthermore, as shown in FIG. 3, an escape groove 82 having a width that does not contact the outer peripheral surface of the finishing roller 18 is formed in the intermediate portion of the roller groove 78. As shown in FIG. In other words, the finishing roller 18 is rotatably supported at its outer circumferential surface near both ends by the rollers a78.

On the other hand, the through hole 80 communicates with the roller groove 78, as shown in FIG. 2, and the outer peripheral surfaces of the finishing roller 18 and the backup roller 20 can come into contact with each other. Although not shown, an appropriate number of annular oil grooves are formed in the through hole 80 so that the lubricating oil is distributed almost evenly around the entire circumference, and even when a relatively large load is applied, the backup roller 20 is designed to slide easily. therefore,
The rotation of the finishing roller 18 is transmitted to the backup roller 20 through contact between their outer peripheral surfaces, and the backup roller 20 is rotated.

As shown in FIG. 3, opposing stop centers 84, 86 are respectively screwed into the side frames 75, 76 so that the distance between the two centers can be adjusted. These dead centers 84 and 86 engage with a pair of center holes 88 provided on both end faces of the backup roller 20, and rotatably support the backup roller 20. In addition,
The center hole 88 is sized to allow slight movement of the backup roller 20 in the radial direction. Further, a pair of regulating surfaces 90 are formed on mutually opposing inner surfaces of the side frames 75 and 76, near both end surfaces of the finishing roller 18, respectively. The regulating surface 90 is a sliding surface that faces both end surfaces of the finishing roller 18 with a slight gap therebetween.

Regarding the second roller section 71, the same elements as those of the first roller section 70 are given the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 2, the middle part of the first arm 72 has a
A support shaft 98 is attached via a holding member 94. The axial center of this support shaft 98 is parallel to the finishing roller 18 and on the tangential plane P at the contact portion T with respect to the finishing roller 18.

Further, on the end surface of the first arm 72 opposite to the first roller section 70, as shown in FIG.
0.101 is provided protrudingly. These support parts 100,1
01, the pins 102 connect both ends of the bin 102 to the finishing roller 1.
It is supported in a posture parallel to 8.

Regarding the second arm 73, the same elements as those of the first arm 72 are given the same reference numerals, and detailed description thereof will be omitted.

The support member 62 rotatably supports the support shafts 98 of the first and second arms 72, 73, as shown in FIG. Moreover, both support shafts 98 are arranged such that both tangent planes P are parallel to each other and the distance between the axes of both support shafts 98 is approximately equal to the outer diameter of the workpiece 14. Therefore, even if the first and second arms 72 and 73 rotate as the outer diameter of the workpiece 14 changes, the position of the contact portion T of both finishing rollers 18 includes the axes of the two support shafts 98. There is almost no change in the direction perpendicular to the plane.

The pressing device 64 presses the first and second roller portions 70 with respect to the support shaft 98 in the first and second arms 72 and 73.
．． It is arranged at a position opposite to 71. This pressing device 64 is equipped with a compression spring 104 that always urges both roller portions 70 and 71 toward each other. In other words, the biasing force of the compression spring 104 acts as roller pressure (processing pressure) that presses the workpiece 14 and the finishing roller 18.

This compression spring 104 is a double coil spring, and each end is supported by a pair of spring seats 106 and 108.

In addition, both arms 7 are attached to the first and second arms 72 and 73.
Coaxial circular holes 1) 0.1) 2 having bottoms on the outside of 2.73 and extending in the pressing direction are formed, respectively.

The compression spring 104 extends and contracts in the same direction as the axial direction of the circular holes 1)0.1)2, and is disposed astride both the circular holes 1)0.1)2. Also, one spring seat 108 has a circular hole 1
) 2, and one end of a push screw 1) 4 is connected to this spring seat 108. The center portion of the push screw 1) 4 is screwed into the second arm 73, and the other end protrudes outside the second arm 73. The other end is provided with a tightening part 1) 6 in which a tightening tool can be secured. Furthermore, this push screw 1
) 4 can be fixed at any position with a locking nut 1) 8. Therefore, the preload of the compression spring 104 can be increased or decreased by moving the push screw 1) 4 forward or backward to decrease or increase the compression force of the compression spring 104.

The stopper 65 is connected to the first and first arms 72. The first and second roller portions 70.7
defines the accessible limit of 1.

This stopper 65 is connected to the first and second abutting members 12 made of steel.
0.122 are respectively fixed to both arms 72 and 73,
One end surface of both of these contact members 120 and 122 is a contact surface that faces each other. During processing, stopper 65
When the roller portions 70 and 71 are prevented from approaching each other, the pressing force of the finishing roller 18 against the workpiece 14 disappears, and finishing is completed. In this embodiment, this state is considered to be the machining completion state, and therefore the machining dimensions of the workpiece 14 are determined by the heights of the abutting members 120 and 122. In addition, both contact members 120, 12
2 are in the state shown in the figure when finishing is started, and are separated from each other, but when not being processed, they are always in contact with each other and the finishing roller 18
to prevent contact with other parts.

The unclamp device 66 includes first and second arms 72 .
A retaining member 126 that can be secured to the bottle 102 of 73 is connected to a rod 130 of an air cylinder 128. The forward and backward movement of this air cylinder 128 is controlled by a control circuit. Further, the air cylinder 128 is fixed to the support member 62 with its axial direction perpendicular to a plane including the axes of both support shafts 98. The retaining member 126 is formed with a contact surface 132 that can come into contact with the outer peripheral surfaces of both the bottles 102, and this contact surface 132 has an inclined surface that converts the forward force of the air cylinder 128 into a force that narrows the distance between the pins 102. We are prepared. As the distance between both pins 102 is narrowed, the distance between the first and second roller portions 70.71 is expanded.

As shown in FIG.
34 is rotatably supported at both ends.

Furthermore, this connecting pin 134 is fixed to the support member 62, so that the supporting member 62 can rotate around the connecting pin 134. In addition, the mounting base 68 and the support member 6
2 by means of a support spring 136 and adjustment means 138. Further, a height adjustment stopper 140 is disposed toward the support member 62 from the mounting base 68.

The support spring 136 elastically supports the support member 62 at a predetermined position. In this embodiment, the center of gravity of the member supported by the connecting pin 134 is
Since the support spring 136 is biased toward the first and second roller portions 70 and 71, the support spring 136 connects the support member 62 to the connecting pin 134.
It is a tension spring that biases counterclockwise in the figure.

That is, these connecting pins 134 and support springs 136 constitute elastic support means.

The adjustment means 138 applies a slight force in the forward and reverse directions to the support member 62 to adjust the relative position of the support member 62 with respect to the mounting base 68.

This adjustment means 138 includes a height adjustment screw 142 and a spring 144.
are coaxially connected. Therefore, by changing the height of the height adjustment screw 142 and changing the amount of compression of the spring 144, the magnitude and direction of the biasing force applied to the support member 62 by the spring 144 and the support spring 136 are changed, and the finishing roller 18 The center height of is changed.

The height adjustment stopper 140 can change the height of the head 146 as an abutting part by changing the depth of screwing into the mounting base 68. The height of the head 146 is set so that it does not come into contact with the support member 62 during processing, but is set at a height that allows it to come into contact with the support member 62 when not in use. Therefore, when not in use, the support member 62 is connected to the connecting pin 134 and the height adjustment stopper 1.
40 to prevent unnecessary rocking.

The feeding device 22 is equipped with a driving device (not shown) for moving the moving table 24, and the feeding speed and amount of this driving device are controlled by a control circuit.

The operation of the apparatus of this embodiment will be explained below.

First, screw in the height adjustment stopper 140 and
Lower the height of 6.

Next, the feeding device 22 is driven to move the roller holding device 16 in the feeding direction, and the finishing roller 18 is brought into contact with the workpiece 14 being rotated by the workpiece driving device 12 . At this time, since the outer diameter of the workpiece 14 is slightly larger than the distance between the finishing rollers 18 when the stopper 65 is in contact with the stopper 65, the first and second roller portions 70 and 71 resist the urging force of the pressing device 64. Expanded.

At the same time, pressing between the workpiece 14 and the finishing roller 18 is started, and the finishing roller 18 and the backup roller 20 begin to rotate as the workpiece 14 rotates. Since the feeding device 22 continues to feed the roller holding device 16 gradually, the pressing positions of the workpiece 14 and the finishing roller 18 are moved in the direction of their axes. By moving the pressing position, the entire outer circumferential surface of the large diameter portion 30 of the workpiece 14 is rolled to a predetermined smooth surface.

Additionally, in the roller holding device 16 of this embodiment, the pair of arms 72 and 73 are connected to the respective support shafts 9.
8 and rotates integrally with a pair of holding members 94 rotatably fitted to the holding members 94 . Therefore, while providing the fitting gap necessary for smooth rotation between the support shaft 98 and the holding member 94,
In order to suppress the amount of wobbling between the two as much as possible, it is desirable that the substantial length of engagement between the support shaft 98 and the holding member 94 is as long as possible. In this embodiment, since the length of the support shaft 98 and the fitting length of each of the pair of holding members 94 can be made approximately equal, the roller holding device 16 is large in order to reduce the amount of wobbling. There is no need to lengthen the support shaft 98, while avoiding the possibility of increase in length.

Although one embodiment of the present invention has been described above based on the drawings,
It goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a roller burnishing device according to an embodiment of the present invention, and FIG. 2 is a side view showing a roller holding device of the embodiment device. FIG. 3 is a plan view partially showing the periphery of the finishing roller of the apparatus of the above embodiment. 10: Roller burnishing device 12: Work drive device 14: Work 16: Roller holding device 18: Finishing roller 20: Back unroller 22: Feeding device 26: Frame 60: Roller mechanism 62: Support member 64: Pressing device 66:
Unclamping device 68: Mounting base

Claims (6)

[Claims] (1) A workpiece with a circular cross section is rotated around its axis, a finishing roller having a smooth outer circumferential surface is diagonally crossed over the workpiece, and both are pressed from a predetermined finishing start position on the workpiece, and the finishing roller By moving the workpiece and finishing roller relative to each other in a direction that intersects their axes within a plane parallel to their axes while rotating the A roller burnishing method characterized in that the outer circumferential surface of the workpiece is smoothed by rolling the workpiece by moving both the rollers in the axial direction. (2) A workpiece drive device that holds a workpiece and rotates it around its axis, a finishing roller and a backup roller with a larger diameter than the finishing roller, which can rotate while contacting each other on their outer peripheral surfaces, and are capable of finishing the workpiece. A roller mechanism in which the roller is held between the backup roller and the workpiece, and the roller mechanism and the workpiece driving device are connected to each other so that the finishing roller and the workpiece are obliquely intersecting each other, and both are on the outer peripheral surface. By bringing the roller mechanism and the workpiece drive device closer together in the processing direction, the frame supports the frame in a state where they can be in contact with each other and can move relative to each other in a processing direction perpendicular to a plane parallel to their axes, and the workpiece can be moved in the processing direction. a pressing device that presses the roller mechanism and the finishing roller; and a feeding device that moves the roller mechanism and the workpiece drive device relatively within the one plane in a direction intersecting the axes of the workpiece and the finishing roller. . (3) The roller mechanism includes a pair of arms that hold the finishing roller and the backup roller in opposing positions with the workpiece in between, and the frame supports the pair of arms. The finishing roller includes a supporting member rotatably supported around an axis parallel to the axis of the finishing roller, and the feeding device moves the supporting member in a direction parallel to the one plane. A roller burnishing device according to claim 2. (4) The pair of arms is provided with a stopper that defines the limit of rotation of the pair of arms in a direction in which both the finishing rollers approach each other.
The roller burnishing device described in Section 1. (5) The frame supports the finishing roller via elastic support means, and the elastic support means:
Claim 2, wherein the finishing roller is held at a predetermined constant position and is allowed to move in the radial direction of the workpiece as the finishing roller starts contacting the workpiece. Roller burnishing equipment. (6) The roller burnishing device according to claim 5, wherein the elastic support means has an adjusting means for adjusting the fixed position of the finishing roller.