JP6388251B2 - Finishing wheel brush and force control finishing method - Google Patents

Description

  The present invention relates to a finishing grindstone brush and a force control finishing processing method for finishing a workpiece by a processing robot.

Finishing is generally a work that adjusts the workpiece after casting or machining to a predetermined shape and surface roughness specified in the drawing by hand, and is deburred, chamfered, rounded, blended, Various processes such as polishing are included.
Among finishing processes, the finishing of complex-shaped parts and precision parts is difficult to automate due to changes in the shape of the parts due to heat treatment, and must be dependent on the experience and skills of skilled workers.
Therefore, there arises a problem that the work quality after finishing varies depending on the skill level of the worker.

In order to solve this problem, it has already been proposed to finish a workpiece by attaching a finishing tool to the hand of the robot arm and operating it along the machining path.
In this case, a tool that holds the brush-like grindstone that is fixed to the spindle, is rotationally driven around the axis, and extends in the axial direction is used as the finishing tool. Such a tool (hereinafter referred to as “grinding brush”) is disclosed in, for example, Patent Documents 1 to 6.

JP 2009-50967 A JP 2013-220510 A JP 2003-136413 A JP 2002-254277 A JP 2002-219656 A JP 2000-210847 A

For example, when the finishing part of the workpiece is a tooth surface of a gear tooth, there may be a non-processed part in the vicinity of the finishing part (for example, a position 4 to 6 mm away). In this case, the conventional grindstone brush has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and when rotated at a high speed (for example, 10,000 rpm or more) around the shaft center, the brush shape is caused by centrifugal force. The end face of the grindstone is enlarged. Further, the end face diameter at the time of enlargement varies depending on the protruding length of the brush and the rotation speed.
Therefore, when the non-processed part exists in the vicinity of the finished portion, the end face of the brush-shaped grindstone is enlarged by the centrifugal force and the non-processed part is processed, so that it is difficult to apply a conventional grindstone brush.

  The present invention has been developed to solve the above-described problems. That is, an object of the present invention is to provide a finished grinding wheel brush that can prevent the linear abrasive from expanding due to the centrifugal force even when the finishing grinding brush is driven to rotate at a high speed (for example, 10,000 rpm or more). And to provide a force controlled finishing method.

According to the present invention, a finishing grindstone brush that is fixed to a spindle, is rotationally driven about an axis, and holds a brush-like grindstone extending in the axial direction,
The brush-like grindstone has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and a cylindrical holding member that holds the end portion of the linear abrasive and is coaxial with the central axis of the linear abrasive And
The finishing grindstone brush has a brush sleeve provided with a diameter expansion prevention hole that is passed through the linear abrasive at the tip and is in close contact with the outer peripheral surface thereof,
Furthermore, a brush holder that accommodates the brush-shaped grinding wheel with the axis centered on the rotation axis of the spindle,
A fastening member for fixing the brush-like grindstone to the brush holder so that the position thereof can be adjusted,
The brush holder has a first hollow cylindrical shaft whose tip is open,
The first hollow cylindrical shaft is provided with a first hollow cylindrical hole that coaxially accommodates the brush-like grindstone, and a first elongated hole that extends in the axial direction on the side surface and communicates the inside and the outside.
The cylindrical holding portion is provided with a female screw hole orthogonal to the axis,
The brush sleeve is an outer sleeve having a second hollow cylindrical hole that coaxially accommodates a distal end portion of the first hollow cylindrical shaft, and an end thereof is opened, and is aligned with the first elongated hole on a side surface of the outer sleeve. Is provided with a second slot that communicates the inside and the outside,
Wherein the fastening member is a low head screw member to reduce the imbalance amount about the axis of the finishing grindstone brush, the low head screw member has a fixing male screw portion to be screwed with the female screw hole, the fixing male thread part through both of the first long hole and the second long hole, said fixing the outer sleeve and the brush holder fastened to the cylindrical holder, the finishing grindstone brush, wherein provided that.

According to the present invention, there is also provided a finishing grindstone brush that is fixed to a spindle, is rotationally driven about an axis, and holds a brush-like grindstone extending in the axial direction,
The brush-like grindstone has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and a cylindrical holding member that holds the end portion of the linear abrasive and is coaxial with the central axis of the linear abrasive And
The finishing grindstone brush has a brush sleeve provided with a diameter expansion prevention hole that is passed through the linear abrasive at the tip and is in close contact with the outer peripheral surface thereof,
Furthermore, a brush holder that accommodates the brush-shaped grinding wheel with the axis centered on the rotation axis of the spindle,
A fastening member for fixing the brush-like grindstone to the brush holder so that the position thereof can be adjusted,
The brush holder has a first hollow cylindrical shaft whose tip is open,
The first hollow cylindrical shaft is provided with a first hollow cylindrical hole that coaxially accommodates the brush-like grindstone, and a first elongated hole that extends in the axial direction on the side surface and communicates the inside and the outside.
The cylindrical holding portion is provided with a female screw hole orthogonal to the axis,
The first hollow cylindrical shaft is provided with a first male screw portion on the outer surface of the tip portion thereof,
The brush sleeve is an outer cap having a second hollow cylindrical hole that coaxially accommodates the first hollow cylindrical shaft and having an open end.
The outer cap has a first female screw portion that is provided on the inner surface of the opening side and is screwed with the first male screw portion,
Wherein the fastening member is a low head screw member to reduce the imbalance amount about the axis of the finishing grindstone brush, the low head screw member has a fixing male screw portion to be screwed with the female screw hole, the fixing male thread only through the first elongated hole of the part, fixed by tightening the brush holder in the cylindrical holder, the finishing grindstone brush, wherein provided that.

According to the present invention, there is also provided a finishing grindstone brush that is fixed to a spindle, is rotationally driven about an axis, and holds a brush-like grindstone extending in the axial direction,
The brush-like grindstone has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and a cylindrical holding member that holds the end portion of the linear abrasive and is coaxial with the central axis of the linear abrasive And
The finishing grindstone brush has a brush sleeve provided with a diameter expansion prevention hole that is passed through the linear abrasive at the tip and is in close contact with the outer peripheral surface thereof,
Furthermore, a brush holder that accommodates the brush-shaped grinding wheel with the axis centered on the rotation axis of the spindle,
A fastening member for fixing the brush-like grindstone to the brush holder so that the position thereof can be adjusted,
The brush holder has a first hollow cylindrical shaft whose tip is open,
The first hollow cylindrical shaft has a first hollow cylindrical hole that coaxially accommodates the brush-like grindstone, a first elongated hole that extends in the axial direction on the side surface and communicates the inside and the outside, and the first hollow cylindrical hole. A second female thread portion located on the inner surface of the tip end side of
The brush sleeve is an inner cap having a second male screw portion that is screwed to the second female screw portion on a distal end side,
The fastening member includes a torque transmission member that is sandwiched between the end surface of the cylindrical holding portion and the end surface of the first hollow cylindrical hole, and transmits a rotational force therebetween, the inner cap, and the cylindrical holding portion. And a compression spring that urges the cylindrical holding portion in the axial direction toward the torque transmission member .

Further, according to the present invention, the above-mentioned finishing grindstone brush is used, the brush-shaped grindstone is rotationally driven around its axis, and is pressed against the finishing portion by force control in the axial direction. There is provided a force-controlled finishing method characterized by finishing the finished portion while preventing enlargement .

The finished part of the workpiece is the gear tooth edge,
(A) The measurement pin is operated by hybrid control of position and force, the edge position of the gear tooth is measured following the curved surface between the gear teeth, and this is compared with the position data acquired in advance. A coarse search step of rotating the workpiece to roughly determine the edge position;
(B) Next, the edge position is measured again by bringing the measuring pin into contact with the gear teeth by force control, and the edge position is compared with the position data acquired in advance. A precise search step for precise determination.

  The finished portion of the workpiece is a portion that has an obtuse edge among the gear tooth edges and is sensitive to displacement.

  According to the above-described apparatus and method of the present invention, the finishing grindstone brush has a brush sleeve provided with a diameter-expansion preventing hole that is passed through the linear abrasive material of the brush-like grindstone at the tip and is in close contact with the outer peripheral surface thereof. . Thereby, even if a finishing grindstone brush is rotationally driven centering on an axial center at high speed (for example, 10,000 rpm or more), the expansion by the centrifugal force of a linear abrasive can be prevented by the diameter expansion prevention hole.

It is 1st Embodiment figure of the finishing grindstone brush of this invention. It is detail drawing of the brush sleeve of FIG. It is assembly explanatory drawing of the finishing grindstone brush of FIG. It is sectional drawing which shows 2nd Embodiment of the finishing grindstone brush of this invention. It is sectional drawing which shows 3rd Embodiment of the finishing grindstone brush of this invention. It is a whole block diagram of a precision finishing robot system. It is a schematic diagram which shows a part of bevel gear which is a workpiece | work. It is a schematic diagram which shows the influence of position shift in the case of gear edge removal. It is a schematic diagram of the positioning operation of the gear teeth.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a first embodiment of a finishing grindstone brush 10 according to the present invention, in which (A) is a side view and (B) is a cross-sectional view taken along line BB in (A).
2 is a detailed view of the brush sleeve 6 of FIG. 1, wherein (A) is a side view, (B) is a cross-sectional view taken along line BB of (A), and (C) is C-- of (B). FIG.
FIG. 3 is an assembly explanatory view of the finishing grindstone brush 10 of FIG.

  In FIG. 1, a finishing grindstone brush 10 of the present invention is fixed to a spindle 20b (see FIG. 6 described later), is driven to rotate about an axis ZZ, and holds a brush-like grindstone 1 extending in the axial direction. It is a grindstone brush.

  As shown in FIG. 3, the brush-like grindstone 1 holds a plurality of linear abrasives 2 whose outer peripheral surfaces are bundled in a cylindrical shape, and a linear portion that holds the end portion (right end portion in the figure) of the linear abrasive 2. It has a cylindrical holding part 3 positioned coaxially with the central axis of the abrasive 2.

  The linear abrasive 2 is a wire made of, for example, an alumina fiber grindstone. The diameter and number of the linear abrasives 2 are arbitrary. The plurality of linear abrasives 2 are tightly bundled without gaps. The plurality of linear abrasives 2 are in close contact with each other, and the gaps are hollow. The cavity may be filled with an adhesive and firmly connected to each other.

  The cylindrical holding part 3 is a cylindrical metal member, and has a hollow cylindrical part that accommodates the end part of the linear abrasive 2 at one end (left end in the figure). The end portions of the plurality of linear abrasives 2 are firmly fixed by caulking or the like of the hollow cylindrical portion. In addition, you may fix by adhesion | attachment other than caulking, integral molding, etc.

The overall outer diameter d of the plurality of linear abrasives 2 is, for example, about 6 mm (4 to 8 mm), and the free length L1 from the cylindrical holding portion 3 is, for example, about 30 mm.
Moreover, the outer diameter D of the cylindrical holding part 3 is about 8 mm (6-10 mm), for example, and the length L2 of the cylindrical holding part 3 is about 10 mm, for example.

  In this example, the cylindrical holding portion 3 is provided with a female screw hole 3a orthogonal to the axis. The female screw hole 3a is preferably penetrated. The size of the female screw hole 3a is, for example, M2.4 to M3.0.

  As shown in FIG. 3, the finishing stone brush 10 of the present invention further includes a brush holder 4.

The brush holder 4 accommodates the brush-shaped grindstone 1 in the inside so that the axis of the brush-shaped grindstone 1 coincides with the rotation axis of the spindle 20b.
In FIG. 3, the brush holder 4 has a first hollow cylindrical shaft 4 a whose tip (left end in the drawing) is open, and is formed coaxially and integrally with the first hollow cylindrical shaft 4 a and extends to the end side (right side in the drawing). And an actual cylindrical fixed shaft 4b. The fixed shaft 4b can be fixed to the rotating shaft of the spindle 20b.
In this example, the first hollow cylindrical shaft 4a includes a first hollow cylindrical hole 5a that accommodates the brush-like grindstone 1 coaxially, and a first elongated hole 5b that extends in the axial direction on the side surface and communicates the inside and the outside. Is provided.
The inner diameter of the first hollow cylindrical hole 5a is slightly larger than the outer diameter D of the cylindrical holding portion 3, and is movable in the axial direction while holding the brush-like grindstone 1 coaxially.
Further, the width of the first long hole 5b is set to a size through which the fixing male screw portion 9b of the low head screw member 9A described later passes and the head portion 9a does not pass.

The finishing grindstone brush 10 of the present invention has a brush sleeve 6 provided with a diameter expansion prevention hole 7 that passes through the linear abrasive 2 of the brush-like grindstone 1 at its tip and is in close contact with the outer peripheral surface thereof. The diameter expansion prevention hole 7 is a through hole extending in the axial direction.
The brush sleeve 6 is detachably fixed to the tip end side (left end side in the figure) of the brush holder 4.

1 to 3, the outer diameter of the brush sleeve 6 is set to a size that does not interfere with the non-processed part adjacent to the finished portion of the workpiece W. The outer diameter of the brush sleeve 6 is about 12 mm (10-14 mm), for example.
In this example, the inner diameter of the diameter expansion preventing hole 7 is slightly larger than the entire outer diameter d of the plurality of linear abrasives 2 and is sized to adhere to the outer peripheral surface through the entire linear abrasive 2. Is set. The inner diameter of the diameter expansion prevention hole 7 is, for example, about 6.2 mm (4.2 to 8.2 mm).
In addition, when there is a gap between the linear abrasives 2, the inner diameter of the diameter expansion prevention hole 7 is set to be equal to the overall outer diameter d of the plurality of linear abrasives 2 as long as the plurality of linear abrasives 2 pass. It may be the same or smaller.

  In this example, the brush sleeve 6 is an outer sleeve 6A having a second hollow cylindrical hole 8a that coaxially accommodates the first hollow cylindrical shaft 4a and having an open end. A side surface of the outer sleeve 6A is provided with a second long hole 8b that is positioned in alignment with the first long hole 5b and that communicates the inside and the outside.

As shown in FIG. 2, in this example, a flat surface portion 8c is provided on the side surface of the outer sleeve 6A in which the second long hole 8b is provided.
The flat surface portion 8c has a width that allows the head portion 9a of the low-head screw member 9A described later to be in close contact with each other.

The finishing grindstone brush 10 of the present invention further includes a fastening member 9 that fixes the brush-like grindstone 1 to the brush holder 4 so that the position of the brush-shaped grindstone 1 can be adjusted.
In this example, the fastening member 9 is a low head screw member 9 </ b> A that reduces the unbalance amount around the axis of the finishing grindstone brush 10. The low head screw member 9 </ b> A has a thin screw head 9 a, and minimizes an increase in the amount of unbalance around the axis of the finishing grindstone brush 10.
Further, the increase in the unbalance amount due to the fastening member 9 is reduced by the decrease due to the first long hole 5b and the flat portion 8c of the outer sleeve 6A, and the dynamic balance around the axis of the finishing grindstone brush 10 is adjusted.

In this example, the fastening member 9 (low head screw member 9A) has a fixing male screw portion 9b that is screwed into the female screw hole 3a.
With this configuration, the low head screw member 9A fastens the outer sleeve 6A and the brush holder 4 to the cylindrical holding portion 3 by fixing the male screw portion 9b for fixing through both the second elongated hole 8b and the first elongated hole 5b.

  With the configuration of the first embodiment described above, the brush-like grindstone 1 is rotationally driven around its axis ZZ, and is pressed against the finished portion with force control in the axial direction to prevent the end face of the brush-like grindstone 1 from being enlarged. While finishing, you can finish the finish.

FIG. 4 is a cross-sectional view showing a second embodiment of the finishing grindstone brush 10 of the present invention.
In this example, the first hollow cylindrical shaft 4a is provided with a first male screw portion 5c on the outer surface (left end in the drawing) of the tip.
The brush sleeve 6 is an outer cap 6B having a second hollow cylindrical hole 8a that coaxially accommodates the distal end portion of the first hollow cylindrical shaft 4a and having an open end.
The outer cap 6B has a first female screw portion 8d on the inner surface of the opening side. The first female screw portion 8d is screwed with the first male screw portion 5c.
In this example, the low-head screw member 9A fastens the brush holder 4 to the cylindrical holding portion 3 by passing the fixing male screw portion 9b only through the first long hole 5b.
Other configurations are the same as those of the first embodiment.

With the configuration of the second embodiment described above, the brush-like grindstone 1 is rotationally driven around its axis ZZ, and is pressed against the finished portion by force control in the axial direction to prevent the end face of the brush-like grindstone 1 from being enlarged. While finishing, you can finish the finish.
Further, in this configuration, the protruding length of the linear abrasive 2 from the outer cap 6B can be adjusted by changing the position of the fastening member 9 while the outer cap 6B is fixed to the first hollow cylindrical shaft 4a. .

FIG. 5 is a sectional view showing a third embodiment of the finishing grindstone brush 10 of the present invention.
In this example, the brush holder 4 has a first hollow cylindrical shaft 4a whose tip is open. The first hollow cylindrical shaft 4a is provided with a first hollow cylindrical hole 5a that accommodates the brush-like grindstone 1 coaxially, and a second female screw portion 5d that is located on the inner surface of the tip end side.
In this example, the first elongated hole 5b in the first and second embodiments is omitted, and an unbalanced amount around the axis is not generated.

  In this example, the brush sleeve 6 is an inner cap 6C having a second male screw portion 6d screwed with the second female screw portion 5d on the end side.

In this example, the fastening member 9 includes a torque transmission member 9c and a compression spring 9d.
The torque transmission member 9c is sandwiched between the end surface 3b of the cylindrical holding portion 3 and the end surface 5e of the first hollow cylindrical hole 5a, and transmits the rotational force therebetween. The torque transmission member 9c is, for example, an elastic member having a large frictional resistance and a disk having irregularities on the surface.
The compression spring 9d is, for example, a coil spring, and is sandwiched between the inner cap 6C and the cylindrical holding portion 3 and urges the cylindrical holding portion 3 in the axial direction toward the torque transmission member 9c.

With the configuration of the above-described third embodiment, the brush-like grindstone 1 is rotationally driven around its axis ZZ, and is pressed against the finishing portion by force control in the axial direction to prevent the end face of the brush-like grindstone 1 from being enlarged While finishing, you can finish the finish.
Moreover, in this structure, the protrusion length from the inner cap 6C of the linear abrasive 2 can be adjusted only by rotating the inner cap 6C.
Further, since the female screw hole 3a and the first elongated hole 5b are not provided and the low head screw member 9A is not used, it is possible to prevent an unbalance amount around the axis of the finishing grindstone brush 10 from occurring.

  The force control finishing method of the present invention uses the above-described finishing grindstone brush 10, rotationally drives the brush-shaped grindstone 1 around its axis, and presses the finished portion in the axial direction by force control, thereby brush-shaped grindstone 1. Finish the finished part while preventing the end face of the steel from expanding.

In the embodiment described later, the finishing portion of the workpiece W is an edge of a gear tooth. The force control finishing method of the present invention has a rough search step S1 and a fine search step S2.
In the rough search step S1, the measurement pin 38 (see FIG. 9 described later) is operated by hybrid control of position and force, the edge position of the gear tooth is measured following the curved surface between the gear teeth, and this is acquired in advance. Compared with the position data, the edge position is roughly determined by rotating the workpiece W.
Next, in precision search step S2, the measurement pin 38 is brought into contact with the gear teeth by force control, the edge position is measured again, and this is compared with the position data acquired in advance, and the edge position is accurately determined. Decide on.

  By this method, it is possible to perform positioning for a gear tooth having no positioning reference using the touch sensing function before finishing.

  FIG. 6 is an overall configuration diagram of a precision finishing robot system that applies intelligent technology to an industrial robot and performs finishing like a human. Hereinafter, the precision finishing robot system is simply referred to as “the present system”.

  This system includes a robot 12, a robot controller 14, a force sensor 16, an ATC 18, a hand 20, a tool 22, a control PC 24, a hand rack 26, a tool rack 28, an indexing table 30, a dressing table 32, an operation touch panel 34, and a PLC 36. Composed.

  The force sensor 16 is attached to the hand of the robot 12. An ATC 18 (Auto Tool Changer) is attached to the force sensor 16. The hand 20 includes a flange 20a attached to the ATC 18 and a spindle 20b. The tool 22 is attached to the spindle 20b. The control PC 24 calculates a target trajectory. The hand rack 26 stores the hand 20. The tool rack 28 stores the tool 22. The indexing table 30 places and rotates the workpiece W. The dressing table 32 dresses the tool 22. The PLC 36 (programmable controller) uses a microprocessor in the same way as other computers and operates by software.

The hand 20 and the tool 22 can be attached and detached using the functions attached to the ATC 18 and the spindle, respectively.
The tool 22 includes a cemented carbide cutter 23 described later in addition to the finishing grindstone brush 10 described above. Hereinafter, it is called a tool unless it is necessary to distinguish.

In this system, when an operator sets a workpiece W on the index table 30 and selects a workpiece model and finishing content on the operation touch panel 34 and starts the operation, the robot 12 uses the index table 30 and the measurement pin 38 to set the workpiece W. After specifying the finishing position, the system performs a series of selected finishing operations while automatically performing hand replacement, tool replacement, and dressing of the tool 22.
The target trajectory is calculated by the control PC 24 based on the robot trajectory data acquired in advance, the force data and torque data acquired in real time from the force sensor 16, and the position data and posture data acquired from the robot controller 14. A position command is sent to. The control cycle is about 12 [ms], for example.

The system has the following four features.
(1) Various spindles 20b and tools 22 can be used properly according to finishing.
The operator finishes the spindle 20b and the tool 22 used for finishing in various ways depending on the finishing content and conditions. The system reproduces such usage using tool change, hand change, position control, force control, and hybrid position and force control.

(2) A finishing trajectory can be created from a CAD model and a CAM.
CAD is software for creating a drawing on the screen of a personal computer. CAM is software for creating a machining program for NC machine tools on a personal computer.
This system can create finishing trajectories offline from CAD models and CAM. Actually, the created trajectory often requires fine adjustment of the trajectory by teaching work, although it depends on the finishing accuracy. This is effective when creating a trajectory that is troublesome for teaching work, such as creating a polished trajectory on a complex curved surface.

(3) The position error of the workpiece W can be compensated.
In the present system, the position error of the workpiece W can be compensated for using the touch sensing function for measuring the position and position of the finished portion by bringing the measuring pin 38 into contact with the workpiece W and finishing with high accuracy.
For high-precision positioning of the workpiece W, it is necessary to use the workpiece's own high-precision machined reference surface with a jig or the like. In many cases, high-precision positioning is difficult because, for example, the reference surface cannot be used due to the burr generated by

(4) A robot language system for finishing can be used.
This system converts a series of operations necessary for finishing into commands and constructs a robot language system for finishing. As an example of the commanded operation, there are operations such as finishing by force control, recording touch sensing measurement results and using them for the finishing operation, and moving peripheral devices such as the spindle 20b.

(Application to bevel gear finishing process)
FIG. 7 is a schematic diagram showing a part of the bevel gear that is the workpiece W. FIG. The work W finished by this system is a part of the bevel gear.
Bevel gears for jet engines have complicated shapes and are precision parts that require high finishing accuracy. In the final finishing process to which this system is applied, various finishes such as chamfering of gear teeth, blending of the entire gear teeth, and blending of oil grooves are performed.
In the following, issues and finishing methods will be described, using bevel gear oil groove blending and gear edge removal as examples.
“Blend” is “an operation for smoothing the finished surface with a slight edge”, and examples thereof include an operation for removing secondary burrs that occur after chamfering and an operation for slightly chamfering and rounding the edge.

  The application location of the oil groove blend is divided into an inner diameter hole edge of a hole formed in the gear cylindrical portion and an inner diameter groove edge formed by groove processing based on the position of the inner diameter hole. Each edge needs to be slightly blended to have a similar shape in all oil grooves.

In FIG. 7, the outer end surface of the edge of the bevel gear has a chamfered edge abcdcef.
That is, the application portion of the gear edge chamfering is the chamfered edge abcdcdf.

Edges at which the angle θ shown by the broken line in the figure forms an acute angle (less than 90 °) are referred to as an acute vertical edge ab and an acute edge bc. Similarly, edges whose angle θ forms an obtuse angle (90 ° or more) are referred to as an obtuse angle edge de and an obtuse angle longitudinal edge ef.
The chamfered edges abcdfef are acute vertical edges ab, acute edges bc, obtuse edges de, obtuse vertical edges ef, and root edges cd. A total of 5 locations are intricately connected.
In addition, the gear edge removal application portion exists in a narrow portion where the gap between the teeth is a maximum of about 5 [mm].
It is necessary to chamfer the chamfered edge abcdcef, which is located in such a narrow portion, so that the chamfering width is constant and smoothly connected, and to have the same shape for all gear teeth.

The issues are the following three points.
(1) There is no standard for positioning.
There are no positioning standards for oil grooves and gear teeth.

(2) The tool 22 to be used is limited.
Since the gear is fixed to the jig (indexing table 30) during finishing, the tool 22 that can be used is limited to a shape that does not interfere with the non-machined portion other than the indexing table 30 and the finishing portion. In the case of an oil groove, since the blend amount is small, the usable tool 22 is limited to a tool having a low cutting force.

(3) It is difficult to finish only by position control.
Since the machining accuracy of the inner diameter groove with respect to the inner diameter hole is low, the position of the inner diameter groove edge differs for each inner diameter groove. Therefore, when finishing is performed by position control, an inner groove edge that cannot be finished is generated.

FIG. 8 is a schematic diagram showing the influence of displacement in the case of gear edge removal. In this figure, (A) is a case of an acute angle edge, and (B) is a case of an obtuse angle edge.
In this figure, the tool 22 is a cemented carbide cutter 23, g is the shape of the finished surface, and b is the width of the finished surface g.

In the case of a gear tooth such as a bevel gear, there is a slight edge displacement Δ caused by heat treatment error, gear attachment error, machining error, and repeated positioning error of the robot 12.
In this case, as shown in FIG. 8, the obtuse edge of (B) has a larger amount of change in the width b of the finished surface g than the acute edge of (A) and is sensitive to the edge displacement Δ, It is difficult to finish each finished surface width with position control.

(Finishing method)
FIG. 9 is a schematic diagram of the gear tooth positioning operation, where (A) shows a rough search and (B) shows a fine search.
For oil grooves and gear teeth that do not have positioning standards, positioning is performed using the touch sensing function before finishing.

  First, the measuring pin 38 is operated by hybrid control of position and force, and the gear tooth position is measured following the curved surface between the gear teeth which has been reworked after the heat treatment process and has high accuracy. In this system, when the measurement pin 38 comes into contact with the curved surface of the tooth tip and the curved surface between the gear teeth cannot be copied, the measurement pin 38 is once separated from the gear, and the indexing base 30 is rotated slightly to perform measurement again. Has retry function.

Next, compared with the gear tooth position acquired in advance, the index base 30 is rotated to roughly determine the position (coarse search).
Then, the gear teeth after the rough search are brought into contact with the measuring pin 38 by force control, the gear tooth position is measured again, and the position is precisely determined by comparison (precise search).
In the case of an oil groove, positioning is performed by performing a rough search and a fine search for the hole from the outer diameter side.

Table 1 shows the tool 22 and the control method in the case of gear edge removal.

  After positioning, the gear teeth are chamfered with the tool 22 and the control method summarized in Table 1. That is, this method finishes the obtuse angle edge der and the obtuse angle longitudinal edge ef, which are “obtuse angle edges” sensitive to edge displacement, by force control using the finishing grindstone brush 10 of the first embodiment, The other edges are finished with a cylindrical carbide cutter 23 having a blade diameter as large as possible.

  It should be noted that in order to avoid tool interference with non-machined parts other than the finished part and smoothly connect the finished surface of the root edge cd to the finished surface of the acute edge and the obtuse edge, the tooth base edge cd which is an obtuse angle edge Uses a carbide cutter 23.

  After positioning, the inner diameter hole edge is blended by pressing a spherical electrodeposition grindstone against the inner diameter hole edge. The inner groove edge is blended by operating a disc rubber grindstone with hybrid position and force control.

  As described above, according to the apparatus and method of the present invention, the finishing grindstone brush 10 is provided with the diameter expansion prevention hole 7 that passes through the linear abrasive material 2 of the brush-like grindstone 1 at the tip and is in close contact with the outer peripheral surface thereof. A brush sleeve 6 is provided. Thereby, even if the finishing grindstone brush 10 is rotationally driven at a high speed (for example, 10,000 rpm or more) around the shaft center, the expansion due to the centrifugal force of the brush-like grindstone 1 (linear abrasive 2) is prevented from being expanded. Can be prevented.

Further, the outer diameter of the brush sleeve 6 is set to a size that does not interfere with the non-processed part adjacent to the finished portion of the workpiece W.
Thereby, even if a non-processed part exists in the vicinity (for example, a position away from 4 to 6 mm) near the finishing part, the brush-shaped grindstone 1 is driven to rotate around its axis without processing the non-processed part, In addition, the finishing portion can be finished by pressing the finishing portion in the axial direction with force control.

  In addition, this invention is not limited to embodiment mentioned above, is shown by description of a claim, and also includes all the changes within the meaning and range equivalent to description of a claim.

W work, 1 brush-like grindstone, 2 linear abrasive, 3 cylindrical holder,
3a female screw hole, 3b end face, 4 brush holder, 4a first hollow cylindrical shaft,
4b fixed shaft, 5a first hollow cylindrical hole, 5b first elongated hole,
5c first male screw part, 5d second female screw part, 5e end face,
6 brush sleeve, 6d second male thread, 6A outer sleeve,
6B outer cap, 6C inner cap, 7 diameter expansion prevention hole,
8a 2nd hollow cylindrical hole, 8b 2nd long hole, 8c plane part,
8d 1st female thread part, 9 fastening member, 9A low head screw member,
9a head, 9b male screw portion for fixing, 9c torque transmission member,
9d compression spring, 10 finishing whetstone brush, 12 robot,
14 Robot controller, 16 Force sensor, 18 ATC,
20 hands, 20a flange, 20b spindle, 22 tools,
23 Carbide cutter, 24 Control PC, 26 Hand rack,
28 tool racks, 30 index tables, 32 dress tables, 34 operation touch panels,
36 PLC, 38 measuring pins

Claims (6)

A finishing whetstone brush that is fixed to a spindle, is driven to rotate about an axis, and holds a brush-like whetstone extending in the axial direction,
The brush-like grindstone has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and a cylindrical holding member that holds the end portion of the linear abrasive and is coaxial with the central axis of the linear abrasive And
The finishing grindstone brush has a brush sleeve provided with a diameter expansion prevention hole that is passed through the linear abrasive at the tip and is in close contact with the outer peripheral surface thereof,
Furthermore, a brush holder that accommodates the brush-shaped grinding wheel with the axis centered on the rotation axis of the spindle,
A fastening member for fixing the brush-like grindstone to the brush holder so that the position thereof can be adjusted,
The brush holder has a first hollow cylindrical shaft whose tip is open,
The first hollow cylindrical shaft is provided with a first hollow cylindrical hole that coaxially accommodates the brush-like grindstone, and a first elongated hole that extends in the axial direction on the side surface and communicates the inside and the outside.
The cylindrical holding portion is provided with a female screw hole orthogonal to the axis,
The brush sleeve is an outer sleeve having a second hollow cylindrical hole that coaxially accommodates a distal end portion of the first hollow cylindrical shaft, and an end thereof is opened, and is aligned with the first elongated hole on a side surface of the outer sleeve. Is provided with a second slot that communicates the inside and the outside,
Wherein the fastening member is a low head screw member to reduce the imbalance amount about the axis of the finishing grindstone brush, the low head screw member has a fixing male screw portion to be screwed with the female screw hole, the fixing male thread through both of the second long hole and the first slot of the section, fixed by tightening the outer sleeve and the brush holder in the cylindrical holder, finishing grindstone brush, characterized in that. A finishing whetstone brush that is fixed to a spindle, is driven to rotate about an axis, and holds a brush-like whetstone extending in the axial direction,
The brush-like grindstone has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and a cylindrical holding member that holds the end portion of the linear abrasive and is coaxial with the central axis of the linear abrasive And
The finishing grindstone brush has a brush sleeve provided with a diameter expansion prevention hole that is passed through the linear abrasive at the tip and is in close contact with the outer peripheral surface thereof,
Furthermore, a brush holder that accommodates the brush-shaped grinding wheel with the axis centered on the rotation axis of the spindle,
A fastening member for fixing the brush-like grindstone to the brush holder so that the position thereof can be adjusted,
The brush holder has a first hollow cylindrical shaft whose tip is open,
The first hollow cylindrical shaft is provided with a first hollow cylindrical hole that coaxially accommodates the brush-like grindstone, and a first elongated hole that extends in the axial direction on the side surface and communicates the inside and the outside.
The cylindrical holding portion is provided with a female screw hole orthogonal to the axis,
The first hollow cylindrical shaft is provided with a first male screw portion on the outer surface of the tip portion thereof,
The brush sleeve is an outer cap having a second hollow cylindrical hole that coaxially accommodates the first hollow cylindrical shaft and having an open end.
The outer cap has a first female screw portion that is provided on the inner surface of the opening side and is screwed with the first male screw portion,
Wherein the fastening member is a low head screw member to reduce the imbalance amount about the axis of the finishing grindstone brush, the low head screw member has a fixing male screw portion to be screwed with the female screw hole, the fixing male thread only through the first elongated hole of the part, fixed by tightening the brush holder in the cylindrical holder, finishing grindstone brush, characterized in that. A finishing whetstone brush that is fixed to a spindle, is driven to rotate about an axis, and holds a brush-like whetstone extending in the axial direction,
The brush-like grindstone has a plurality of linear abrasives whose outer peripheral surfaces are bundled in a cylindrical shape, and a cylindrical holding member that holds the end portion of the linear abrasive and is coaxial with the central axis of the linear abrasive And
The finishing grindstone brush has a brush sleeve provided with a diameter expansion prevention hole that is passed through the linear abrasive at the tip and is in close contact with the outer peripheral surface thereof,
Furthermore, a brush holder that accommodates the brush-shaped grinding wheel with the axis centered on the rotation axis of the spindle,
A fastening member for fixing the brush-like grindstone to the brush holder so that the position thereof can be adjusted,
The brush holder has a first hollow cylindrical shaft whose tip is open,
The first hollow cylindrical shaft has a first hollow cylindrical hole that coaxially accommodates the brush-like grindstone, a first elongated hole that extends in the axial direction on the side surface and communicates the inside and the outside, and the first hollow cylindrical hole. A second female thread portion located on the inner surface of the tip end side of
The brush sleeve is an inner cap having a second male screw portion that is screwed to the second female screw portion on a distal end side,
The fastening member includes a torque transmission member that is sandwiched between the end surface of the cylindrical holding portion and the end surface of the first hollow cylindrical hole, and transmits a rotational force therebetween, the inner cap, and the cylindrical holding portion. And a compression spring that urges the cylindrical holding portion in the axial direction toward the torque transmission member. 4. The brush-like grindstone using the finishing grindstone brush according to any one of claims 1 to 3, wherein the brush-like grindstone is rotationally driven around its axis, and is pressed against the finishing portion by force control in the axial direction. A force-controlled finishing method, wherein the finishing portion is finished while preventing the end face of the sheet from being enlarged. The finished part of the workpiece is the gear tooth edge,
(A) The measurement pin is operated by hybrid control of position and force, the edge position of the gear tooth is measured following the curved surface between the gear teeth, and this is compared with the position data acquired in advance. A coarse search step of rotating the workpiece to roughly determine the edge position;
(B) Next, the edge position is measured again by bringing the measuring pin into contact with the gear teeth by force control, and the edge position is compared with the position data acquired in advance. The force control finishing method according to claim 4 , further comprising a precise search step that is precisely determined. 5. The force-controlled finishing method according to claim 4 , wherein the finishing portion of the workpiece is a portion having an obtuse angle edge among the gear tooth edges and sensitive to displacement.

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