JP2015229221A - Burnishing tool, burnishing device, and burnishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burnishing tool, a burnishing device, and a burnishing method which can finish spherical surface parts with different spherical diameters by using the same burnishing tool.SOLUTION: A burnishing tool 6 which performs surface finishing of spherical work-piece 12, comprises: a rod-like shank part 1; a frame 2 that is connected to a tip of the shank part 1 while central axes thereof are aligned with each other; and a working member 3 that is held while being aligned with the central axis center of the frame 2. In the burnishing tool, the working member 3 has a working surface 4 recessed in a semi-circular arc shape. By moving a center 9 of the working surface 4 recessed in the semi-circular arc shape along a driving locus 10 in a circular arc shape, the working surface 4 recessed in the semi-circular arc shape is pressed along a surface of a spherical part of the work-piece 12, and the surface of the spherical part of the work-piece 12 is burnished.

Description

  The present invention relates to a spherical processing tool, a processing apparatus, and a processing method for finishing a spherical surface or a hemispherical surface formed at an end of a shaft portion.

  As background art of this technical field, there is JP 2008-194791 A (Patent Document 1). In this publication, “surface finishing of a spherical workpiece using a roller burnishing tool comprising a frame that rotates about an axis that intersects the rotation axis of the workpiece and a roller that is rotatably supported by the frame” is disclosed. The roller is configured to roll the surface of the workpiece while performing planetary movement along the surface of the workpiece in a direction intersecting with the rotation axis of the workpiece as the frame rotates. (Claim 1) ”.

JP 2008-194791 A

  In the configuration of Patent Document 1 described above, it is not necessary to rotate the frame along the surface of the work, and the roller makes a planetary motion as the frame rotates, and the surface of the rotating work is rolled from multiple directions. Then, the spherical workpiece is finished. However, since the spherical shape that can be machined is limited depending on the tool shape, it is necessary to replace the tool for machining workpieces having different spherical diameters, and there is a problem that a period and cost for preparing the tool are required each time.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spherical burnishing tool, a burnishing processing device, and a burnishing tool capable of finishing a spherical portion having different spherical diameters with the same burnishing tool and suppressing tool wear by using the tool machining surface in a wide range. It is to provide a burnishing method.

In order to solve the above-described problems, the present invention employs the configurations described in the claims.
The present invention includes a plurality of means for solving the above-mentioned problems. If an example of the burnishing tool of the present invention is given, a rod-shaped shank portion, a frame that is connected to a tip of the shank portion with a central axis aligned, and A burnishing tool for performing surface finishing of a spherical workpiece having a machining portion held in accordance with a center axis of the frame, wherein the machining portion has a machining surface recessed in an arc shape. It is what.

  Further, if one example of the burnishing apparatus of the present invention is given, a burnishing tool having a machining surface recessed in an arc shape is held, a mechanism for rotating around the central axis, and a workpiece to be processed having a spherical portion are held. A mechanism that rotates about the central axis, a mechanism that adjusts an angle at which the central axis of the burnishing tool and the central axis of the workpiece intersect, and maintains the adjusted angle, the burnishing tool, and the Surface finishing of a spherical workpiece having a mechanism for moving the workpiece in a relatively three-dimensional manner is performed.

  In addition, if an example of the burnishing method of the present invention is given, a burnishing tool having a machining surface that is recessed in an arc shape is held, a mechanism that rotates around the central axis, and a workpiece that has a spherical portion are held. A mechanism that rotates about the central axis, a mechanism that adjusts an angle at which the central axis of the burnishing tool and the central axis of the workpiece intersect, and maintains the adjusted angle, the burnishing tool, and the A burnishing method for performing surface finishing of a spherical surface portion of a workpiece using a burnishing device having a mechanism for moving the workpiece in a relatively three-dimensional manner. By moving the center of the processing surface along an arc-shaped locus, the processing surface depressed in the arc shape is pressed along the surface of the spherical portion of the workpiece, and the surface of the spherical portion of the workpiece is pressed. Roll Machining is characterized in that.

  According to the present invention, by using a burnishing tool having a processing portion recessed in an arc shape, by controlling the crossing angle of the workpiece and the tool and the movement trajectory of the tool, the same burnishing tool can be used. The spherical surface can be finished. Therefore, it is not necessary to replace the tool for each spherical diameter, the preparation time and cost of the tool are unnecessary, and it is possible to flexibly cope with a design change of the product.

  Furthermore, since the tool machining surface is used in a wide range, the wear of the tool can be suppressed and stable machining can be performed.

It is sectional drawing of the burnishing tool of Example 1 of this invention. It is a side view which shows the processing state of the spherical workpiece by the burnishing tool of Example 1 of this invention. It is a side view which shows transition of the processing state of the to-be-processed member which has a spherical surface part with a small spherical diameter by the burnishing tool of Example 1 of this invention. It is a side view which shows transition of the processing state of the to-be-processed member which has a spherical surface part with a large spherical diameter by the burnishing tool of Example 1 of this invention. It is a side view which shows transition of the processing state of the spherical workpiece by the burnishing tool which has the process surface dented in the circular arc shape of the range narrower than a semicircle of Example 2 of this invention. It is a side view which shows transition of the processing state of the spherical to-be-processed member by the burnishing tool which has the processing surface which the recessed part of Example 3 of this invention dented in the semi-elliptical shape. (A) is explanatory drawing for calculating | requiring the drive locus | trajectory which moves a process surface along the surface of a spherical workpiece in the burnishing tool which has a process surface where the cross section was dented in the semi-elliptical shape, (b) FIG. 5 is an explanatory diagram for obtaining a driving locus for moving a machining surface along a surface of a spherical workpiece in a burnishing tool having a machining surface recessed in a semicircular arc shape.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing for explaining the embodiment, elements having the same function are given the same name and reference numeral, and repeated explanation thereof is omitted.

  In this embodiment, for the finishing of the spherical surface of the workpiece, a burnishing tool having a semicircular arc-shaped machining portion is used, and the crossing angle of the workpiece and the burnishing tool and the movement trajectory of the burnishing tool are controlled. An example of finishing a workpiece having spherical surfaces with different spherical diameters in the same burnishing tool will be described.

  FIG. 1 is a cross-sectional view of the burnishing tool of the present invention.

The burnishing tool 6 includes a frame 2 connected to the end of the rod-shaped shank portion 1 in alignment with the central axis, a center of the processing surface 4 having a semicircular arc-shaped cross section, and the center axis of the frame 2 to match the frame 2 And a fixing member 5 for fixing the processing member 3 to the frame 2.
The machining surface 4 that is recessed in a semicircular arc shape has the same semicircular arc shape in any cross section passing through the center thereof.
The fixing member 5 is a set screw, and uses the screw holes formed in the frame 2 to fix the processed member 3 to the frame 2. The fixing method is not limited to the method using a set screw, and may be fixed by other known means such as screwing.

The processing surface 4 that is recessed in a semicircular arc shape of the processing member 3 is formed with high accuracy by polishing or grinding, which are existing processing methods. The processed member 3 is made of a hard material, and tungsten carbide, ceramic, cermet, high-speed steel, or the like is used.
Further, the shank portion 1, the frame 2, and the processed member 3 are not necessarily separate members, and may have an integrated structure as long as each constituent member fulfills its function.

  FIG. 2 is a side view showing a processing state of a spherical workpiece by the burnishing tool of the present invention.

  The shank portion 1 is held by a tool holder 8 connected to the drive shaft 7 of the machine tool, and the rotational drive of the drive shaft 7 is transmitted to the burnishing tool 6 to rotate. A workpiece 12 having a spherical surface at the shaft end is connected to a drive shaft (not shown) of a machine tool and is driven to rotate. The number of rotations of the burnishing tool or workpiece is adjustable. The central axis of the burnishing tool 6 and the central axis of the workpiece 11 intersect at an angle θ. The crossing angle θ is adjusted, and the adjusted angle is maintained. The burnishing tool 6 can be moved relative to the workpiece 12 in three axial directions (X, Y, Z) by a machine tool.

  By moving the center 9 of the machining surface 4 recessed in a semicircular arc shape along the arcuate drive locus 10 with the intersection angle θ fixed, the machining point 11 of the machining surface 4 recessed in the semicircular arc shape is obtained. Moves along the spherical surface of the workpiece 12. The semicircular arc-shaped drive locus 10 is controlled by the drive shaft of the machine tool, and by adjusting the drive locus 10, it is possible to perform burnishing (rolling pressing) with an equal amount of pressing on the spherical surface portion of the workpiece 12. .

  Further, the speed difference is provided by changing the rotational speed of the workpiece 12 as compared with the rotational speed of the burnishing tool 6. In particular, when the rotational speed of the workpiece 12 is made smaller than the rotational speed of the burnishing tool 6, the processing surface 4 that is recessed in a semicircular arc shape with respect to the spherical surface portion of the workpiece 12 is used per time. The contact time can be extended and burnishing is effectively performed. For this reason, the rotational speed of the workpiece 12 is preferably at least 1/10 or less of the rotational speed of the burnishing tool 6.

  Further, the burnishing is performed by reciprocatingly swinging the center 9 of the surface 4 of the burnishing tool 6 that is recessed in a semicircular arc shape along the drive locus 10.

  The burnishing tool of the present embodiment is mounted on a multi-tasking machine such as a machining center that can be moved in three axial directions by controlling the inclination of the burnishing tool, and can be driven to rotate on the workpiece. After performing the roughing by the above, by changing the tool to the burnishing tool of the present embodiment, it is possible to perform the processing from roughing to finishing with the same combined processing machine.

  FIG. 3 is a side view showing a transition of a machining state of a workpiece having a spherical portion with a small spherical diameter by the burnishing tool of the present invention. 3A is a position near the shaft portion in the spherical portion of the workpiece, FIG. 3B is a position near the tip in the spherical portion of the workpiece, and FIG. 3C is a spherical portion of the workpiece. A state in which the vicinity of the tip below the center axis is being processed is shown.

3A to 3C, the intersection angle between the center axis of the burnishing tool 6 and the center axis of the workpiece 12 is constant at θ1. By moving the center 9 of the machining surface 4 recessed in a semicircular arc along the arcuate drive locus 10, the workpiece is machined from a position close to the axis of the spherical surface portion of the workpiece 12 (FIG. 3A). Burnishing can be performed while moving the processing point 11 to the vicinity of the tip of the spherical portion below the central axis of the member 12 (FIG. 3C). Since the workpiece 12 is rotating, machining is performed over the entire spherical portion of the workpiece 12 by machining from a position close to the axis of the spherical portion to the vicinity of the tip below the central axis of the spherical portion.
Further, the machining surface 11 can be used on average by moving the machining point 11 on the machining surface 4 that is recessed in a semicircular arc shape. For this reason, wear on the tool surface can be suppressed.

  FIG. 4 is a side view showing a transition of a machining state of a workpiece having a spherical portion having a large sphere diameter by the burnishing tool of the present invention. 4A is a position near the shaft portion in the spherical portion of the workpiece, FIG. 4B is a position near the tip in the spherical portion of the workpiece, and FIG. 4C is a spherical portion of the workpiece. A state in which the vicinity of the tip below the center axis is being processed is shown.

  4A to 4C, the intersection angle between the center axis of the burnishing tool 6 and the center axis of the workpiece 12 is constant at θ2. By moving the center 9 of the machining surface 4 recessed in a semicircular arc along an arcuate drive locus 10, a position near the axis of the spherical surface portion of the workpiece 12 (from Fig. 4A) Processing can be performed while moving the processing point 11 up to the vicinity of the tip of the spherical portion below the central axis (FIG. 4C).

The burnishing tool 6 shown in FIGS. 3 and 4 has the same shape, and the workpiece can be machined with different sphere diameters by adjusting the crossing angle and the movement trajectory.
Since the curved drive locus becomes small and control becomes difficult, the spherical diameter of the spherical surface portion of the workpiece 12 is about 85% or less with respect to the spherical diameter of the machining surface 4 recessed in a semicircular arc shape. Is preferred.

By using a burnishing tool having a semicircular arc-shaped machining surface according to this embodiment and controlling the crossing angle of the central axis and the movement trajectory of the machining surface while rotating the workpiece and the burnishing tool, different diameters are obtained. A workpiece having a spherical surface can be finished with the same burnishing tool.
In addition, since the push-in amount is controlled by a machine tool having a three-axis control mechanism, it is possible to further increase the accuracy of the burnishing surface by using a highly accurate machine tool.
Therefore, the same tool can be used to finish different spherical spheres by burnishing, eliminating the need for tool design and production time for each sphere diameter, and reducing tool costs. Even when the design is changed, it is possible to respond flexibly.

In the present embodiment, an example will be described in which a finishing process is performed on a workpiece having a spherical portion by using a burnishing tool having a machining surface recessed in an arc shape in a range narrower than a semicircle.
The basic configuration is the same as that of the first embodiment except that a burnishing tool having a machining surface recessed in an arc shape in a narrower range than the semicircle is used, and the description of the portions having the same functions is omitted.

  FIG. 5 is a side view showing a transition of a machining state of a spherical workpiece by a burnishing tool having a machining surface recessed in an arc shape in a range narrower than a semicircle. 5A is a position close to the shaft portion in the spherical portion of the workpiece, FIG. 5B is a position close to the tip in the spherical portion of the workpiece, and FIG. 5C is a spherical portion of the workpiece. A state in which the vicinity of the tip below the center axis is being processed is shown.

  In FIG. 5A, the workpiece 12 has a spherical portion 14 having a radius SRw at the end of the shaft portion 13. An angle from the end of the spherical portion 14 on the shaft portion 13 side to the central axis is defined as a sphere range angle α. In FIG. 5B, the angle of the machining surface 24 that is recessed in an arc shape in a range narrower than the semicircle is a curved surface range angle β.

  The radius SRt of the machining surface 24 that is recessed in the arc shape in a range narrower than the semicircle is larger than the radius SRw of the workpiece 12 and the curved surface range angle β of the machining surface 24 that is recessed in the semicircular arc shape is the workpiece. The sphere range angle α of the member 12 is made larger.

  As described above, since the workpiece 12 rotates around the central axis, the spherical portion 14 has an angle range larger than the sphere range angle α from the end on the shaft portion 13 side of the spherical portion 14. By machining up to the tip below the central axis, burnishing can be performed in the entire spherical portion 14.

  By adjusting the intersection angle θ3 between the center axis of the burnishing tool 6 and the center axis of the workpiece 12 and controlling the arcuate movement trajectory 20, the radius SRt and the curved surface range angle β of the arcuately machined surface 24 are controlled. Thus, it is possible to burn the workpiece 12 having a spherical surface where both the radius SRw and the spherical angle α of the spherical surface are small.

  Note that the burnishing is performed for an angle wider than the spherical angle α in order not to generate an unprocessed portion. Therefore, it is preferable that the curved surface range angle β of the machining surface 24 recessed in a semicircular arc shape in a range narrower than the semicircle is larger than the spherical angle α of the spherical portion 14 of the workpiece 12 by about 3 degrees or more. .

In the present embodiment, an example will be described in which a burnishing tool having a machining surface with a semi-elliptical cross section is used to finish a workpiece having a spherical surface.
The basic configuration is the same as that of the first embodiment except that the burnishing tool having a machining surface with a semi-elliptical cross section is used, and the description of the portions having the same functions is omitted.

FIG. 6 is a side view showing a transition of a machining state of a spherical workpiece by a burnishing tool having a machining surface having a semi-elliptical cross section. 6A is a position near the shaft portion in the spherical portion of the workpiece, FIG. 6B is a position near the tip in the spherical portion of the workpiece, and FIG. 6C is a spherical portion of the workpiece. A state in which the vicinity of the tip below the center axis is being processed is shown.
In FIG. 6, the processed surface 34 having a semi-elliptical cross section has the same semi-elliptical shape in any cross section passing through the center 9.
By moving the center 9 of the machining surface 34 whose section is recessed in a semi-elliptical shape along the drive path 30 having an elliptical arc shape, a position close to the axis of the spherical surface portion of the workpiece 12 (see FIG. 6A). Processing can be performed while moving the processing point 11 to the vicinity of the tip of the spherical portion below the central axis of the processing member 12 (FIG. 6C).

  By making the machining surface concave in a semi-elliptical cross section, the cutting speed on the long radius side can be increased compared to the machining surface recessed in a semicircular arc shape having the same radius as the short radius. Speed difference can be increased.

  Next, a method for calculating the drive locus at the center of the recessed machining surface of the burnishing tool of this embodiment will be described.

  FIG. 7A is an explanatory diagram for obtaining a drive locus for moving the machining surface along the surface of the spherical workpiece in a burnishing tool having a machining surface having a semi-elliptical cross section. b) is an explanatory view for obtaining a driving locus for moving the machining surface along the surface of the spherical workpiece in a burnishing tool having a machining surface recessed in a semicircular arc shape.

  In FIG. 7A, the center Ow of the spherical portion of the workpiece 12 is the origin, the center axis of the workpiece 12 is the Z axis, and the axis passing through Ow and perpendicular to the Z axis is the X axis. The radius of the spherical surface of the workpiece 12 is r, the machining point at the angle φ is P, the major radius of the machining surface 34 in which the section of the burnishing tool 6 is recessed in a semi-elliptical shape is a, the minor radius is b, and the center point is Ot. , The angle of the central axis of the burnishing tool with respect to the X axis is λ.

  The driving locus is an example in which the center axis of the burnishing tool is calculated in parallel with the Z axis, and then the coordinates are converted at the intersection angle θ.

  When the center axis of the burnishing tool is parallel to the Z axis, λ is 90 ° (π / 2 (rad)).

  The movement trajectory of the center point Ot of the machining surface 34 of the burnishing tool 6 for bringing one point of the machining surface 34 whose cross section of the burnishing tool 6 is recessed into a semi-elliptical shape into contact with the machining point P of the spherical surface portion of the workpiece 12 is shown. The coordinates (Xo, Zo) are obtained by the following formula.

  In Equations 1 and 2, by reducing the radius r of the spherical surface portion of the workpiece 12 by the amount of pressing, a movement trajectory in which the pressing amount is added to the spherical portion of the workpiece 12 can be obtained. By converting the coordinates of the obtained movement trajectory in accordance with the intersection angle θ between the center axis of the burnishing tool and the center axis of the workpiece, the movement trajectory during actual machining can be obtained.

  When machining with an elliptical trajectory with a burnishing tool having a semi-elliptical machining surface, the radius r of the spherical surface of the workpiece is r with respect to the major radius a and minor radius b of the burnishing tool machining surface. A material satisfying <b ^ 2 / a can be processed.

  Moreover, in Formula 1 and Formula 2, by making the short radius b the same length (b = a) as the long radius a, as shown in FIG.7 (b), it has a processing surface dented in a semicircular arc shape. When the burnishing tool is used, it is possible to obtain a driving locus for moving the machining surface along the surface of the spherical workpiece.

  In addition, this invention is not limited to an above-described Example, Various modifications are included.

  For example, in the above-described embodiment, the example in which the central axis of the burnishing tool is machined at a constant angle has been shown for easy understanding of the present invention. However, the machining surface of the burnishing tool is moved along the spherical surface portion of the workpiece. If possible, there is no problem even if the angle of the central axis of the burnishing tool is changed during machining.

  Moreover, it is set as the state shifted to the Y-axis direction (direction perpendicular to the plane formed by the central axis of the burnishing tool and the central axis of the workpiece) shown in FIG. 2 with respect to the central axis of the workpiece. Since the machining point on the machining surface of the burnishing tool is pushed into the spherical surface of the workpiece, the pushing amount may be adjusted by this method. In this case, the machining is performed without passing through the midpoint of the machining surface of the burnishing tool, but there is no problem, and the invention is not necessarily limited to one having all the configurations described.

  In addition, the arc-shaped cross section of the concave machining surface of the burnishing tool includes a semicircle, an arc shape smaller than the semicircle, and a semielliptical shape.

  In addition, a part of the configuration of each embodiment can be replaced with the configuration of another embodiment, and the configuration of each embodiment can be added to the configuration of each embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  According to the present invention, by using a burnishing tool having a machining surface that is recessed in an arc shape, by controlling the crossing angle of the workpiece and the tool and the movement trajectory of the tool, the same burnishing tool can be used. The spherical surface can be finished. The present invention can be used for finishing a member having a spherical portion, for example, a ball joint used for a suspension of an automobile or the like, a piston rod used for a hydraulic pump / motor of a construction machine or the like.

DESCRIPTION OF SYMBOLS 1 Shank part 2 Frame 3 Machining member 4 Semicircular arc shaped machining surface 5 Fixed member 6 Burnishing tool 7 Machine tool drive shaft 8 Tool holder 9 Center of semicircular arc shaped machining surface 10 Drive locus 11 Machining point 12 Workpiece member 13 Shaft part 14 Workpiece member spherical surface 20 Drive track 24 Processed surface 30 recessed in an arc shape in a range narrower than a semicircle 30 Drive track 34 Processed surface recessed in a semi-elliptical shape

Claims (13)

Surface finishing of a spherical workpiece including a rod-shaped shank portion, a frame connected to a tip of the shank portion with a center axis aligned, and a processing portion held in accordance with the center axis of the frame. Burnishing tool,
The burnishing tool, wherein the machining portion has a machining surface recessed in an arc shape. The burnishing tool according to claim 1,
A burnishing tool having a semicircular shape or a circular arc shape or a semi-elliptical shape that is narrower than the semicircular shape in a cross section of the processing surface that is recessed in the arc shape. A mechanism for holding a burnishing tool having a machining surface recessed in an arc shape and rotating it around its central axis;
A mechanism for holding a workpiece having a spherical surface and rotating it around its central axis;
A mechanism for adjusting an angle at which the central axis of the burnishing tool and the central axis of the workpiece intersect, and maintaining the adjusted angle;
A burnishing apparatus for performing surface finishing of a spherical workpiece having a mechanism for relatively moving the burnishing tool and the workpiece in a three-dimensional manner. The burnishing apparatus according to claim 3,
A burnishing apparatus characterized in that a cross section of the arcuately machined surface has a semicircular shape or an arc shape or a semi-elliptical shape narrower than the semicircle. The burnishing apparatus according to claim 3,
The burnishing apparatus according to claim 1, wherein a radius of the spherical surface portion of the workpiece is smaller than a radius of the machining surface recessed in the arc shape. The burnishing apparatus according to claim 3,
The burnishing apparatus according to claim 1, wherein a spherical range angle of the spherical portion of the workpiece is narrower than a curved surface range angle of the arcuately processed surface. A mechanism for holding a burnishing tool having a machining surface recessed in an arc shape and rotating it about its central axis, a mechanism for holding a workpiece to be processed having a spherical surface and rotating it about its central axis, and the burnishing A mechanism that adjusts an angle at which the central axis of the tool and the central axis of the workpiece member intersect and maintains the adjusted angle, and the burnishing tool and the workpiece member are moved relatively three-dimensionally. A burnishing method for performing a surface finish of a spherical surface portion of a workpiece using a burnishing device having a mechanism,
By moving the center of the arcuate machining surface along an arcuate path, the arcuate machining surface is pressed along the surface of the spherical surface of the workpiece, and the workpiece A burnishing method, comprising: rolling a surface of a spherical portion of a member. The burnishing method according to claim 7,
A burnishing method characterized in that a cross section of the arc-shaped machining surface has a semicircular shape or an arc shape or a semi-elliptical shape narrower than the semicircle. The burnishing method according to claim 7,
The burnishing method according to claim 1, wherein a radius of the spherical surface portion of the workpiece is smaller than a radius of the machining surface recessed in the arc shape. The burnishing method according to claim 7,
The burnishing method according to claim 1, wherein a spherical range angle of the spherical portion of the workpiece is narrower than a curved surface range angle of the machining surface recessed in the arc shape. The burnishing method according to claim 7,
The burnishing method, wherein the arcuate locus is arcuate or elliptical. The burnishing method according to claim 7,
The burnishing method, wherein the number of rotations of the workpiece is smaller than the number of rotations of the burnishing tool. The burnishing method according to claim 7,
Burnishing is performed by shifting the center axis of the burnishing tool in a direction perpendicular to the plane formed by the center axis of the burnishing tool and the center axis of the workpiece with respect to the center axis of the workpiece. Burnishing processing method characterized by performing.

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