CA1313308C - Grinding machine and grinding method - Google Patents

Grinding machine and grinding method

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Publication number
CA1313308C
CA1313308C CA000533872A CA533872A CA1313308C CA 1313308 C CA1313308 C CA 1313308C CA 000533872 A CA000533872 A CA 000533872A CA 533872 A CA533872 A CA 533872A CA 1313308 C CA1313308 C CA 1313308C
Authority
CA
Canada
Prior art keywords
grinding
grindstone
teaching
workpiece
moving
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA000533872A
Other languages
French (fr)
Inventor
Noboru Nagase
Masao Yamaguchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nagase Iron Works Co Ltd
Original Assignee
Nagase Iron Works Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP1986051093U external-priority patent/JPS62161963U/ja
Priority claimed from JP61078596A external-priority patent/JPS62236662A/en
Priority claimed from JP61078595A external-priority patent/JPS62236661A/en
Priority claimed from JP61081575A external-priority patent/JP2555319B2/en
Priority claimed from JP61081572A external-priority patent/JPS62241649A/en
Priority claimed from JP61081573A external-priority patent/JPS62241650A/en
Priority claimed from JP61145410A external-priority patent/JPS632659A/en
Priority claimed from JP61145411A external-priority patent/JPS632660A/en
Priority claimed from JP13055986U external-priority patent/JPS6335578U/ja
Priority claimed from JP61233953A external-priority patent/JPS6389262A/en
Priority claimed from JP61233952A external-priority patent/JP2569295B2/en
Priority claimed from JP61307445A external-priority patent/JPS63156649A/en
Application filed by Nagase Iron Works Co Ltd filed Critical Nagase Iron Works Co Ltd
Application granted granted Critical
Publication of CA1313308C publication Critical patent/CA1313308C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

ABSTRACT OF THE DISCLOSURE:
The present invention relates to a grinding machine and a grinding method. The grinding machine comprises a pair of opposed upright columns,a cross rail extended between the upper ends of the upright columns,a first moving mechanism mounted on the cross rail for reciprocal movement in a horizontal direction, a second moving mechanism mounted on the first moving mechanism for reciprocal movement in the direction perpendicular to the movement of the first moving mechanism,a third moving mechanism mounted on the second moving mechansim for vertical movement and an abrasive-stone head mounted on the third moving mechanism and having an abrasive stone The grinding steps comprises the steps of teaching the desired grinding paths by displacing the abrasive stone along the surfaces to be ground of a workpiece and storing only the desired grinding paths in a storage device independent of the velocity of the abrasive stone in the teaching step;and repeatedly causing the reciprocal movement of the abrasive stone in a predetermined range only following the desired grinding paths stored in the storage device.

Description

TITL~ OF ~ . IllVI~ TIO2~:
~rinding ivlachine and Crinding llethod Field of the Invention The present invention relates to a grinding machine and a grincling method for grining the impression or cavity surfaces in dies.
])escription of the ~.elated Art The grinding machines or performing a grinding operation in which a horizontally extended upper supporting frame is supported by the columns of a frame in such a way it is movable forwardl~ or baclcwardly; a moving body is mounted on the upper supporting frame in such a way that it is transversely movable;ancl a grindstone head is mounted on the l~oving body in such a way that the head is vertical movable have been well known to those skilled in the art.
In the grinding machines of the type described above, the uppper frame together witll tlle moving l~ody and the ~rindstone head are moved on the columns so that the position of tlle grindstone llead is varied in tlle forward or backward direction. Therefore, the guide and supporting frames for the upper frame must be disposed on both sides of the frame,so that the ~rinding machines are complicated in construction. ~urthermore,sucll guide and supporting frames close both of the right an~ left sides of the frame,so that there exists a problem tllat it is ver~ cumbe~soMe to handle a worlcpiece '-or inserting it into and removing it from the interior of the frame. In addition,in the case of grinding the surfaces having ~, -1- ~

,.. . , ... ~ .. .......

complex shapes as in the cases of dies,the grindstone must be pressed against a surface to be ground and displaced follo~7ing the variation in shape of the surface to be ground.
It is also known to those skilled in the art a grinding machine o~ the type in which a mounting member is vertically movably supported on a moving body whicll is supported on the frame n such a way that the moving body can move in mutually perpendicular in a_horizontal plane/
directions/and tl~e grindstone hea(l is vertically movably mounted on tlle mounting member.
IIowever,in the case of grinding a vertically e.~tended sur~ace to be ground by such grinding machine,when a new surface is to be ground after grinding of a surface, the direction or angle of the grindstone mouned on the grinding llead must be varied. Xspecially when the surface portions are ~rmed continuously each other in a curved state and are extended vertically, the grindstone mounting direction or angle is changed very frequently and repeatedly,so that there exists the problem that the grinding e~ficiency is extremely decreased.
In this ~rinding machine,the changirlg in position in the vertical direction of the grindstone head is limited only to a position adjacent to the grindstone head. Therefore,there exists the problem that the displacement stroke of the grindstone head is limited,so that the grinding machine cannot grind the relatively large-si~ed workpieces.
It is also known to those skilled in the art a grinding machine in which the mounting member is vertivally movably mounted on the moving body which in turn is supported by the f~ame in such a way that it is movable in mutually perpendicular directions and the grinclstone head is mo~mted on the mounting member in such a way that the head can rotate about not only the traversely horizontally exter~-ded axis but also the axis which is perpendicular to the first-mentioned axis and is extended forwardly and backwardly.
~ Iowever,in this grinding machine, the grindstone head is rotatably mounted on the mounting member which in turn is vertically movable and the center of rotation of the grindstone head is displaced in response to the movement in the vertical direction of the mounting member. Therefore,the distance between the grindstone head and the center of rotation thereof is always maintained constant. As a result, the range of the displacement of the grindstone head is limited of its rotation range and is narrow, so that there exists the problem that the grinstone cannot reach an elongated deep portion of a workpiece.
Meanwhile,the grinding tool is disclosed in Japanese Utility ~odel Publication l~1O.37-2028. A ball-and-socket joint is attached to power transmission means whicll in turn is attached to the leading end of the driving shaft and a plurality of projections are e~uiangularly extended along a circumferential direction from the inner wall of the spherical hole of the ball-and-socket joint. Furthermore, the ball of the ball-and-socket joint which is formed with enlongated sliding grooves adapted to engage with the projections,respectively, is fitted into the spherical hole in such a way that it becomes impossible to remove tl~e ball out of the spherical hole. A pad 13t3308 provided with a sheet of sandpaper is securely attached with screws with a flat head to the lower end of tlle leg portion of the ball-and-soclcet joint. In addition, a compression spring is loaded between the pad plate and the power transmission means so that the grinding operation can be easily carried out in response to the projections and valleys or recesses of a surface to be ground without changing the angle of inclination of the driving shaft.
With the grinding tool of the type described above, the force which presses the grinding machine to the surface to be ground acts on the ball-and-socket joint at the vertex of the inner wall of the ball-shaped hole of the ball-and-socket joiint spaced apart from the sandpaper. Therefore, when the pad plates follows the projections and valleys on the surface to be ground so that the center axis of the driving shaft crosses at an angle with the center axis of the pad plate,the pad plate tends to move away from the surface to be ground due to ~e gre~t~ distance from the top of the ball-and-socket joint to the sandpaper. In order to overcome this problem,a bias spring is provided to bias the pad plate or the diameter of the pad plate is selected to be by far greater than the distance between the top of tlle ball-and-socket joint and the sandpaper.
Such grinding tools have the problems that the number of component parts is increased,the construction is complicated and their assembly is cumbersome.A further problem is that it is difficult to decrease the diameter of the pad plate,so that the projections and valleys having relatively small curvature of radius ~ .

cannot be ground satisfactorily in practice.
S~R~ OF THE INVENTIO~:
One of the objects of the present invention is to provide a grinding machine whicll can facilitate the handling of a worlcpiece including the insertion and the discllarge after the completion of the grinding process.
A further object of the present invention is to provide a grinding machine whicll can easily grind the workpiecesof various sizes.
A further object of the present invention is to provide a grinding machine which can sufficiently make a grindstone reach into the deepest portion of a surface to be ground.
A further object of the present invention is to provide a grinding machine which can sequentially grind the surface to be ground of a workpiece.
A further object of the present invention is to provide a grinding machine which can efficiently grind the surface to be ground of a workpiece.
A further object of the present invention is to provide a grinding machine and a grinding method in which the switching between the energized state and the de-energized state of a pressure application cylinder can be made in a simple manner.
A further object of the present invention is to provide a grinding machine and a grinding method which can easily store the data concerning the grinding paths.
A further object of the present invention is to provide a grinding machine and a grinding method which can accomplish the grinding operation with a higll degree of efficiency without the need of indicating a grinding path at each grinding step.
A further object of the present invention is to provide a grinding method whicl-l can eliminate the displacement of a grindstone head from the end of its displacement to the starting point thereof after the completion of the teaching step,whererby the grinding operation is much facilitated.
A further object of the present invention is to provide a grinding machine and a grinding method which can substantially prevent a grindstone from striking against the projections of a surface to be ground.
A further object of the present invention is toprov~de a grinding machine and a grinding method which can eliminate the grinding operation in the case whenoverload is acting on a grindstone and the repetition of the grinding operation in accordance with an erratic data of grinding paths,whereby the safe grinding operation can be ensured.
A further object of the present invention is to provide a grinding machine which can grind a surface to be ground uniformly and with a high degree of accuracy without causing an~J grinding variations such as insufficient grinding of the recessed portions of the surface to be ground and excessive grinding of the projected portions thereof.
A further object oE the present invention is to provide a grinding machine which can reduce the transmission of vibrations of a grindstone to the frame to a minimum.
A further object of the present invention is to provide a grinding machine which can easily grind even a small portion of a surface to be ground and having a complicated pattern.
A further object of the present invention is to provide a grinding machine which can simplify the constructions of a moving body and a frame.
A further object of the present invention is to improve the capability of a grindstone following a surface to be ground, whereby the grinding operation can be accomplished smoothly.
A further object of the present invention is to provide a grinding machine which can cause a grindstone to follow the projections and valleys each having a relatively small radius of curvature so that the uniform grinding operation can be ensured.
A further object of the present invention is to provide a grinding machine which can avoid the interfer-ence between an air cylinder and a rotation mechanism due to the rotation of a grindstone head.
A further object of the present invention is to provide a grinding machine which can eliminate the step carried by an operator for changing the attachment conditions of a grindstone to a grindstone head depending upon the direction of a surface to be ground,whereby the efficiency of the grinding operation can be improved.
A further object of the present invention is to provide a grinding machine and a grinding method which,in case of the displacement of a grindstone along an erratic path in the teaching step,can eliminate the step for repeating the teaching step from its begining and also eliminate a waste of a machining time in the playback step and the variations in respective erratic grinding paths due to the excessive grinding.
A further object of the present invention is to provide a grinding machine and a grinding method which can permit the smooth continuation of the teaching step without any interruption.
A further object of the present invention is to provide a grinding machine and a grinding method which can permit the simple and quic~ correction operation in the teaching step.
To the above and other ends,the present invention provides a grinding machine characterized ~y comprising a pair of upright columns installed in opposing relationship with eacll other,a supporting frame extended between the upper ends of the upright columns,a first displacement mechanism mounted on the supporting frame in such a way that it is reciprocably movable in the horizontal direction,a second displacement mechanism which is mounted on the first displacement mechanism and is adapted to reciprocably move in the horizontal direction perpendicular to the direction of the displacement of the first displacement mechanism,a third displacement mechanism mounted on the second displacement mechanism for reciprocable movement in the vertical direction and a grindstone head which has a grindstone and is mounted on the third displacement mechanism.
Moreover the present invention provides a grinding method characterized by the steps of storing a predetermined grinding path by displacing a grindstone head along a surface to be ground by a teaching mechanism and causing the gri rl(~sLone to repeatedly reciprocate within a predetermined range according to the grinding paths stored in a stoage device.
The other objects of the present invention will become apparent from the preferred embodiments thereof to be described in detail hereinafter and from the scope of the claims and various novel features of the present invention which are not described in this specification will become apparent to those skilled in the art when the present invention is carried out.
BRIEF DESCRIPTION OF THE DRAWINGS:
Fig.l is a front view with parts broken away and parts shown in full of a first embodiment of the present inven~ion;
Fig.2 is a sectional view taken along the line II-II of Fig.l;
Fig.3 is a partial sectional view,on enlarged scale, taken along the line III-III of Fig.2;
Fig.4 is a front view with parts broken away and parts shown in full of a second embodiment of the present invention;
Fig.5 is a sectional view taken along the line V-V of Fig.4;
Fig.6 is a isectional view illustrating on an enlarged scale the construction of a grindstone head;
Fig. 7 is a side view thereof also illustrating the construction of the grindstone head;
/ Fig.~ is a diagram of an air supply control circuit for controlling the actuating of an air cylinder which pushes a _g_ grindstone;

Fig.9 is a front view,on enlarged scale,of a control panel;
Fig.10 is a front view,on enlarged scale,of a teaching device;
Fig.ll is a block diagram o the control circuit;
Fig.12 is a front view with parts broken away and parts shown in full of a fourth embodiment or a die polishing machine in accordance with the present invention;
Fig.13 is a front view illustrating another modification;
Fig.14 is a front view of a fifth embodiment or a die polishing machine in accordance with the present invention;
Fig. 15 is a longitudinal sectional view of a sixth embodiment or a grinding tool in accordance with the present invention;
Fig. 16iS a top view of a grindstone;
Fig. 17 is a front view of a die grinding machine;
Fig. l8 is a longltudinal sectional view illustrating a modification of the grinding tool;
Fig. 19is a front view with parts broken away and parts shown in full of a grindstone head of a seventh embodiment in accordance with the present invention;

Fig. 20 is a front view of a grinding machine;
Fig. 21 is a sectional view, on enlarged scale, taken along the line XXI-XXI of Fig. 19;
Fig. 22 is a top view of a die used to explain the mode of grinding operation thereof;
Fig. 23 is a front view of a grinding machine;
Figs. 24 and 25 are front views illustrating attachments, respectively, each equipped with a grindstone;
Fig. 26 is a perspective view of an eighth embodiment or a die polishing machine in accordance with the present invention;
Fig. 27 is a top view of the die used to explain the teaching step; and Fig. 28 is a block diagram of a control circuit for die polishing machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Now referring to Figs. 1-3, a first embodiment of a grinding machine in accordance with the present invention will be described in detail hereinafter.
The frame 1 of the grinding machine has a gantry-like construction consisting of a horizontally elongated box-shaped base 2, a pair of upright columns 3 extended from the surface of the base 2 adjacent the lateral sides, respectively, thereof and a horizontally extended upper supporting frame 4 extended between the upper ends of the upright columns 3 and securely 3~ attached thereto. Each of the upright columns 3 comprises a large-diameter stationary S~ ' ' . 1313308 cylinder 3a, a gIlide cylinder 3b fitte(l into and securely attachetl to the upper end l)ortion of the large-(liameter stationary cyliTIder 3a and a small-cliaIlIeter movaI~le cylinder 3c telescopically fitted into the guicle c~Jlinder 3c for vertical movement A pair of sliding guides 5 and 6 are disposed on the upper and lower surfaces of the upper supporting frar,~e 4 along each oE tlIe front and rear sides thereof I7itIlin each of the upriglIt columns 3 is vertically extended a threaded lif t rod 7 for rotation and the upper end of the threaded rod 7 is threadably engaged with the bottom of the movable cylinder 3c A reversible lift motor ~ is mounted in the base 2 The motor 8 is drivingly coupled through a driving pulley~ 9, an e~dless belt 10, a driven pulley 11, a recIuction gear 12, right and left transmission shafts 13 extended horizontally, driving gears 14 antl a driven gears 15 to the threaded rods 7 so that upon rotation of tlle motor 8, the threaded rods 7 are rotatecl,whereby the movable cylinders 3c are move(I vertically in unison with the upper supporting frame 4 A moving body 15is supported on the upper supporting frame 4 of the frame 1 and is guided by the guides 5 and 6 in such a way that the moving body 16 is moved in the horizontal or X-dlrection An Y.-direction movement lead screw 17 is rotatably mounted on the bottom of the upper supporting frame 4 and is threadably engaged with a threaded ball member 1~ within the X-direction moving bocly 16 An X direction reversible motor 19 is mounted at the left end of the upper supporting member 4.Upon rotation or the motor 19, the lead screw 17 is rotatecl through a transmission t313308 shaft 20 so tllat the ~ direction moving body 16 is caused to move to the left or rigllt ( or in the horizontal direction).
A Y-direction moving body 21 substantially U-shaped in cross section is supported by the X-direction moving body 16 and is guided by a pair of right and left guide 22 extended througll the ,~-direction moving body 16 so that the Y-~irection moving body 21 can be moved forwardly or baclcwardly. A Y-direction lead screw 23 is rotatably mounted on the Y-direction moving body 21 and is threadably engaged with an internally threaded ball member 24 within the ~-direction moving body 16. A Y direction reversible motor 25 is mounted at the rear end of the Y direction moving body 21. Upon rotation of the Y direction motor 25, the lead screw 23 is rotated so that the 'I-direction moving body 21 is moved forwardly or backwardly.
A cylindrical gear case 26 is attached to the front end of the Y-direction moving body 21.A first rotating body 27 is supported through an annular guide rail 2~ at the front end surface of the gear case 26 in such a way that the first rotating body 27 can rotate about a horizontal axis extended forwardly and baclcwardly.
A first rotation operation handle 29 is disposed on the right side of the gear case 26. Upon rotation of the operation handle 29, the first rotating body 27 is caused to rotate through a predetermined angle through a worm 30 and a worm wheel 31.
A pair of projected walls 27a are extended forwardly of the front surface of the first rotating body 27 and a second rotating body 32 is supported between the pair of extended walls 27a through a pair of pins 33 in such a way that tlle second rotating body 32 is rotatable about an axis which is perpendicu]ar to the axis of rotation of the first rotating bocly 27 and is extended both in the right and left directions. A second rotating handle 34 is disposed on the right side of the first rotating body 27. Upon the rotation of tl~e handle 34,the second rotating body 32 is caused to rotate tl~rough a predetermined angle through a worm 35 and a worm wheel 36.
A Z-direction moving body 37 in the form of a cylinder is extended through the second rotating body 32 and is guided by a guide 38 for vertical movement. A cylinder 39 is securely mounted on the second rotating body 32 so as to surround the Z-direction moving body 37. A Z-direction reversible motor 40 is mounted on the upper end of the supporting cylinder 39. A Z-direction lead screw 41 is extended downwardly from the motor 40 and is threadably engaged with an internally threaded ball member 42 of the Z-direction moving body 37.Upon rotation of the Z-direction motor 40,the lead screw 41 is rotated so that the Z-direction moving body 37 is caused to move vertically.
The upper end of a guide and supporting sha~t 43 is attached to the lower end of the Z direction moving body 37 and is extended downwardly through a coupling 44. A sliding body 45 is supported by the guide and supporting shaft 43 for vertical movement. A supporting arm 46 is swingably or pivotably pivoted to one side of the sliding body 45 with a pivot pin 47 extended horizontally. A grindstone head 48 is pivotably attached to the 13t3308 end of the supporting arm 46 with a pivot pin 49 extended horizontally.
A grindstone 50 is detachably attached to the lower end portion of the grindstone head 4~. Upon energization of an air motor mounted in the grindsone head 4~,the grindstone 50 is reciprocated fowardly and backwardly tllrougll an oscillation generator 51. In this case,it should be noted that instead of causing the swinging oscillation,the grindstone 50 may be rotated. A cylinder 52 is disposed at one side of the sliding body 45 and the upper end of its piston xod 53 is securely attached to the coupling 44.
Upon energization of the air cylinder 52,the sliding body 45 is forcibly moved downwardly so that the grindstone 50 is pressed against the surface to be ground of a workpiecelOlto be described in detail hereinafter.
~ leanwhile a pair of forwardly and backwardly extended guide rails 54 is laid on the base 2 of the frame 1 between the upright columns 3. A table 55 rides on the guide rails 54 through a plurality of wheels 56 in such a way that the table 55 can move forwardly or baclcwardly. A workpiece 101 such as a die is mounted on the upper surface of the table 55. The table 55 is moved forwardly or bac~wardly by a motor (not shown) so that the workpiecellis brought to a position immediately below the grindstone 50;that is,the grinding position or moved away therefrom.
Next the mode of operation of the grinding ~achine with the above-described construction will be described.
In case of grinding the surface to be ground of the workpiece 101 such as the surface of an impression or cavity in a die with the t313308 grinding machine of the type described above,the workpiece 101 is mounted on the table 55 and is brought to the grinding position immediately below the grindstone 50 as shown in Fig.2. In this case,as described above,the frame 1 has the gantry-like construction consisting of the base 2,the pair of upright columns 3 and the upper supporting frame 4 so that the whole right and left sides of the frame 1 are openedJso that the handling of the workpiece 101 including the loading and unloading it into and out of the frame 1 is much facilitated.
Thereafter upon rotation of the lift motor ~, the lead screws 7 in both the upright columns 3 are rotated so that the uprigllt columns 3 are moved vertically and consequently the upper supporting frame 4 is also moved vertically. l~len the X-, YT and Z-direction motors 19,25 and 40 are energized, the lead screws 17,23 and 41 which are drivingly coupled with these motors,respectively, are rotated so that the X-,Y- and Z-direction moving bodies 16,21 and 37 are displaced in the ,~,Y and Z directions,respectively,and consequently the grindstone head 48 is caused to displace itself in the right and left direction ( or the lateral direction in parallel with the upper supporting frame 4),in the forward and backward direction ( or the longitudinal direction in parallel with the guide rails 54) and in the vertical direction ( in parallel with the upright columns 3). In this manner, the grindstone head 48 can be displaced to a position adjacent to the surface to be ground of the workpiece 101 in a simple manner.In this case,it should be noted that the range of the vertical displacement o~
the grindstone head 48 can be made large due to the adjustment of the telescopic movement of the upright columns 3 and due to the adjustment of tlle displacement of the moving body 37 in the Z-direction. As a result,the grinding machine can grind workpieces in various si~es and shapes.
Iinlen the first and second handles 29 and 34 are rotated, he Z-direction moving body 37 is rotated in the left or right direction lon~itudinal/
about the ~ axis (extended for~ardly or backwardly~and also in the forward or backward direction about the lateral axis. In this case, the center of rotation in both directions of the Z-direction moving body 37 is always maintained at a predetermined position so that the vertical displacement takes place while the Z-direction moving body 37 is rotated in an arbitrary direction. Therefore,the grindstone head 48 can be displaced over a wide range so that it can reach a narrow deep portion of the surface to be ground of the workpiece 101.
~ hen the air cylinder 52 is energized under these con-ditions,the grindstone head 48 is further biased to move downwardly so that the grindstone 50 is pressed against the surface to be ground of the workpiece 101. When the air motor in the grindstone head 4~ is energized under these conditions,the grindstone 50 is forced to reciprocate forwardly and backwardly through the oscillation generator 51. Therefore,the grindstone 50 can be displaced arbitrarily in the lateral,longitudinal or vertical direction along the surface to be ground of the workpiece lOl,whereby the surface of the workpiece 101 can be successively ground.

~ eferring ne~t to Fig.s.4-8,a secon(l embodiment of the present invention will be described in detail. In the second embodiment,the ~-,Y- and Z- direction motors are servomotors 20~,213 and 220 and the workpiece 101 is also mounted on a table 225.
First tlle consturction of a grindstone head 219 will be described in detail with reference to Figs.6 and 7. A guide and supporting rod 231 is attached to the lower end of a Z-direction moving body 21~ through a rotary coupling 232 consisting of a stationary disk 233 and a movable disk 234. A sliding body 235 is vertically movably supported by the guide and supporting rod 231. A supporting arm 236 is pivotably attached to one side of the sliding body 235 with a laterally extended pivot pin 237.
An air motor 233 is pivotably attached to the lower end of the supporting arm 236 through a supporting cylinder 240 with a pivot pin 239 laterally extended. The air motor 238 is always maintained in an upright position under the forces of a plurality of springs 241 as shown in Fig.6. A grindstone 242 is attached to the lower end of the supporting cylinder 240 through an oscillation generator 243. Upon rotation of the air motor 238,the grindstone 242 is forced to reciprocate forwardly and backwardly through the oscillation generator 243.
As best shown in Fig.6,a first air cylinder 244 which is pressure application means is disposed on one side of the sliding body 235. The upper end of the piston rod 246 extended from the piston 245 of the air cylinder 244 is securely attached to the rotary disk 234 of the rotary coupling 232. Of the three ,~-,Y- and Z-directions of the displacement of the grindstone head 219,two directions ( for instance,X- and Y-directions) are selected and when,upon energization of the ~- and Y-direction motors 203 and 213,the grindstone head 219 is displaced in both the X- and Y-directions so as to grind the surface to be ground 104 of the impression or cavity in the workpiece lOl,the sliding body 235 is biased to move in the remaining direction;that is,in the Z-direction ( in the downward direction)/
/under-lhe-l~orc-e-o-f-rhe flrs~ air cylinder 244 so that the grindstone 242 is pressed against the surface to be ground 104.
As shown in Fig.7,a second cylinder 247 which is pressure ~ throughl application means is pivitably attacl-ed t~-a mounting plate 248 with a pivot pin 249 to the rear end portion of the sliding body 235 . The le.ading end of the rod 251 extended from the piston 250 of the second :air cylinder 247 is connected through a connecting member 252 to the supporting arm 236.A spring stopper 253 is attached through a supporting member 254 to the front portion of the sliding body 235 for engagement with the supporting arm 236,thereby restricing the rest position thereof. In .case of grinding the surface to be ground 104 at the bottom of the workpiece 101 by displacing the grindstone head 219 in both the ~- and Y-directions as described above, the second air cylinder 247 is maintained in the de-energized state and because of the engagement of the supporting arm 236 with the spring stopper 253,the supporting arm 236 is maintained in the substantially vertical rest position as indicated by the solid lines in Fig.7.

t313308 ~ len the ~- and Z-directions are selected as two directions in which the head 219 is displaced and furthermore when the grindstone head 219 is maintained through the rotary coupling 232 at the position indicatd in Figs.5 and 7 or at the position angularly spaced apart therefrom by 180 so as to grind the front and rear surfaces to be ground 103 of the workpiece 101, the second air cylinder 247 is switched to the energized mode so that the supporting arm 236 is rotated in the counterclockwise direction in Fig.7,whereby the grindstone 242 is pressed against the forward or bacl;ward surface to be ground 103 of the workpiece lOl. In additionlwhen the Y- and Z-directions are selected as the directions in which the grindstone head 219 is displaced and furthermore when the grindstone head 219 is rotated from the position indicated in Figs.5 and 7 through the rotary coupling 232 in the clockwise or counterclockwise direction by 90 so as to grind the right or left surface to be ground 102 of the workpiece lOl,the second air cylinder 247 is also switched into the energized state so that the supporting arm 236 is rotated and consequently the grindstone 242 is pressed against the right or left surface to be ground 102.
~ eferring back to Fig.4,a control panel 257 having switches and the like for selectlng the direction of the displacement of the grindstone head 219 is suspended through a supporting rod 258 on the right side of the frame 201. The grinding machine is further equipped with a teaching device 259 for previously storing the grinding paths traced by the grindstone head 219 manually.
Next referring to Fig.~,the control circuit for controlling the first and second air cylinders 244 and 247 will be described below.
In the control circuit as shown in Fig.o,an air source261 is co~nunicated witl two pairs o~ air supply lines 262 and 263;and 264 and 265. Directional control-valves 266a,266b,267a and 267b for controlling the air supply and discharge are provided in the air supply lines 262 and 264. Furthermore,pressure cotnrol valves ~6~,269,270 and 271 are provided into the air supply lines 262-265,respectively. In the pair of air supply lines 262 and 263, one pressure cotnrol valve 268 is set at a pressure including a pressure compensation component for compensating for the weight of the sliding body 235 which is lower than a set point o~ the other pressure control valve 269. In the other pair of air supply lines 264 and 265,one pressure cotnrol valve 270 is set at a pressure higher than a set point o~ the other pressure control valve 271.
The air is supplied into one cylinder chamber of the first air cylinder 244 through the directional control valve 266a and the pressure control valve 260 illcluded in the air supply line 262 while the air is supplied into the other cylinder chamber through the pressure control valve 269. The air is charged into one cylinder chamber of the second air cylinder 247 through the directional control valve 266b and the pressure control valve 270 of the air supply line 264 while the air is charged into the other cylinder chamber through the pressure control valve 271 of the air supply line 265.
~ e~t the mode of operation of the grinding machine with the above-mentioned construction will be described below.

1 3 1 330~
First,as shown in Fig.5,the workpiece 101 such as a die is mounted on the table 225 and is moved to and located at the grinding position immediately below the grindstone head 219. In case of grinding the bottom surface 104 of the workpiece lOl,the switches on the control panel 257 are so actuated that the two driections;that is,the X- and Y-directions in which the grindstone head 219 moves are selected. Then, as shown in Fig. 8, the directional control valves 266a an~ 267b are turned on while the directional control valves 266b and 267a are turned off.Then the air cylinder 244 is energized while the second air cylinder 247 remains in the inoperative or de-energized state. The first air cylinder 244 causes the grindstone 242 to press against the bottom surface 104 at a predetermined pressure in the do~ward direction. Under these conditions,the air motor 23~ is energized so that the grindstone 242 is caused to reciprocate while the grlndstone head 219 is displaced in a desired direction in the ~- and Y-directions by the ~- and Y-direction motors 20~ and 213,whereby the grindstone 242 grinds the bottom surface 104.
In this case,the pressing force exerted to the grindstone 242 from the first air cylinder 244 is determined depending upon the dif~erence in pressure set point between the pressure control valves 268 and 269. ~nlen the surface to be ground 104 is smooth, the pressure e~erted to the grindstone 242 is maintained at a pre-determined level,but when the projected portions of the surface 104 to be ground is ground,the pressure e,~erted to the grindstone 242 is set at a low level while when the recessed portions are ground, the pressure applied to the grindstone 242 is set at a hi~h level.
The setting of tlle pressures exerted to the grindstone 242 may be made by a computer in the teaching step ~y use of the teaching device 259.
I~ext in case of grinding the forward or baclcward surface to be ground 103 of the workpiece lOl,the grindstone head 219 is rotated through the rotary coupling 232 to the position indicated in Figs.5 and 7 ~r ~o tha~ rotc~t~d: by 180. Mext,the Y~ and Z-directions are selected as the directions in which the grindstone head 219 is displaced. Then the control valves 266a and 267b are turned off while the ~ control valves 266b and 267a are turned on. As a result, the first air cylinder 244 is de-energi~ed while the second air cylinder 247 is energized so that the grindstone 242 is pressed against the forward or baclcward surface to be ground 103 under a predetermined pressure. Under these conditions,the grindstone 242 is caused to reciprocate while the grindstone head 219 is displaced in both the X- and Z-directions by the ~Y- and Z-direction motors 20~ and 220,whereby the grindstone 242 grinds the forward or baclcward surface 103 of the workpiece 101.
Furthermore,in the case of grinding the right or left surface to be ground 102 of the workpiece lOl,the grindstone head 219 is rotated from the position indicated in Figs.5 and 7 to the position angularly displaced from the first-mentioned position by 90 in the ciockwise or counterclockwise direction. Mext the Y- and Z-directions are selected as the directions in which the grindstone head 219 is displaced. Then,as described above, the control valves 266a and 267b are turned off while the control valves 266b and 267a are turned on. As a result,the first air cylinder 244 is de-energized while the second air cylinder 247 is energized so that the grindstone 242 is pressed against the right or left surface 102 to be ground at a predetermined pressure. Under these conditions,the grindstone 242 is reciprocated while the grindstone head 219 is displaced in the Y- and Z-directions by the Y- and Z-direction motors 213 and 220,whereby the grinstone 242 grinds the right or left sur~ace 102 to be ground.
As described above,according to the present invention, of the three directions;that is,the Y-,Y- and Z-directions, two directions in which the grindstone head 219 is displaced are selected while in the remaining one direction,the grindstone 242 is pressed against the surface to be ground 102,103 or 104 under a predetermined pressure so that the grinding of the surfaces to be ground can be accomplished very efficiently. The switching between the energized state and the de-energized state of each of the pressure application air cylinders 244 and 247 can be easily accomplished in response to tile OM-OFF operations of the control valves 266a,266b,267a and 267b.
So far it has been described that the control valves 266a,266b,267a and 267b are alternately turned on so that the first and second air cylinders 244 and 247 are alternately energized, but it is to be understood that all the flowcontrol valves are simultaneously turned on so that the both the air cylinders 244 and 247 are concurrently energized,thereby accomplishing the grinding operation. Moreover, the control valves 266a, 266b, 267a, 267b, can be omitted from the circuit.

l3l33as Referring next to I~'igs.~--lI`,a third embodiment of the present invention will be described in comparis on with tlle second mbodiment.
the /
In the cnse of/teacllin~ step with a teaching device 359 and in the case of the grinding step accomplished in accordance witll the data o grinding paths stored in the teaching step, the detection of an overload acting on a grindstone 2;42 will be des-cribecl. As hest shown in Fig.6, a first pair of overload sensors 361 and 362 sucll as magnetic sensors are disposed at the upper and lower stroke ends,respectively,of a piStOII 245 in opposing relationsllip witll each other withill a first air cylinder 244. In the case o f grinding tlle surface to be grolmd 104 in the ~- and Y-directions, when an overload occurs,tlle upper or lower sensor 361 or 362 generates a detection signal in response to an abnormal approach oE the piston 245 to the upper or lower sensor 361 or 362. In case of grinding the surface to be ground 102 in the Y- and Z-directions or the surface to ~e ground 103 in the ~- and Z-directions, the upper overload sensor 361 detects the uppermost strolce position of the piston 245 ( at which tlle grindstone 242 is located its lowermost position),thereby determining the normal position of the grindstone 247.
As shown in Fig. 7,a second pair of overload ~ensors 363 and 364 are dispose(l at the uppermost and lowermost stroke ends, respectively,of a piston 250 in opposing relationship with each other in the second air cylincler 247.When an overload acts on the grindstone 242 in the lateral direction or longitudinal direction in case oi- grinding the surfaces to be ground 102 and 103, tlle overload sensors 363 and 364 deliver the detection signal in response to an abnormal approach of the piston 250 to the left or right sensor 363 or 364. In case of grinding the surface to be groulld 103, the le~t sensor 363 shown in Fig. 7 detects the piston 250 displaced to ltS leftmost position ( at which the supporting arm 236 is maintained in a vertical position), thereby determining the normal position of the grinclstone 242.
Furthermore,a fourth overload sensor 366 such as a magnetic sensor is disposed in a supporting member 254. ~len an overload which forces the supporting arm 236 to rotate in the clockwise direction in Fig. 7 in the case of grinding the surface 104 to be ~ro~md,the overload sensor 366 generates a detection signal in response to an abnorrnal compression of the stop spring 253 in the supporting melllber'254.
Referring bacl; to Fig.6 again,a third overload sensor 365 such as a magnetic sensor is disposed on the outer surface of an air motor 23~. I~en an overload acts on the grindstone 242 in such a manner tllat the grindstone 242 is forced to rotate abouth a pivot pin 239,the overload sensor 365 generates an overload detection signal in response to an abnor~al approach to the supporting arm 236.
Xeferring next to Fig.9, the arragement of switches on a control panel 357 will be described. A mode selection switch 371 for selecting the manual operation mode,the teaching mode or tlle grinding mode is disposed at the upper left portion of the control panel 357 an(l display lamps 372a,372h and 372c are located at the mode selection positions,respectively,of the selection switch 371. A direction selection switch 373 for selecting the directions in whicll a grin(lstone head2,19 is displaced is located below the mode selection swticll 371 and display lamps 374a,374b and 374c are disposed at the selected direction positions,respectively, of the direction selection switch 373. That is, the display lamp 374a,374b or 374c is turned on in response to the selection of the Y- and Z-directions ,the ~- and '~-directions or the X- and Z-directions.
A teaching-mode operation region 375 is allocated at the center portion of the control panel 357. A display lamp 376 which is turned on when the mode selection switch 371 has selected the teaching mode is disposed at the upper portion of the region 375.
A velocity selection switch 377 for selecting a velocity of dis-placement of the grindstone head 219 in the teaching mode or step is located wi~in the operation region 375. Display lamps 37~a, 378b and 378c co~espon~n~ to the low,medium and high velocities, respectively, are disposed a~ the positions,respectively,of the velocity selection switch 377 within the operation region 375.
A display device 379 for displaying a remaining period of time during which the grincling operation can be further stored in the teaching mode or step is disposed below the velocity selection switch 377. A start switch 380 for starting the teaching mode or step and an end switch 3~1 for interrupting the teaching mode of step are disposed on the left side of the operation region 375.
~3R2J
An operation-mode operation region-Y~s allocated at the ri~t portion of tlle control panel 357. A display lamp 383 which is turned on wllen the mode selection switcll 371 has selected the grinding mode is disposed at the llpper portion of the region 382.
A processing time indicator 384 for previously setting the whole grinding time and a time display device 385 for displaying the remaining time in the grinding mode or step are disposed at the right side within the operation region 382. A start switch 386 for starting the grinding mode or step and an end switch 3S7 for interrupting the ~rinding mode or step are disposed on the left side withirl the operation region 382.
Referring next to Fig. lo,the construction of the teaching device 359 will be described below. An operation handle 391 is extended fowardly from tlle right side of the front surface of the teaching device 359 in such a way that it can be inclined and rotated in a desired direction from the top to the left side as indicatec by the arrows marked on the front surface of the teaching device 359. A pair of direction display lamps 392 and 393 and another pair of direction display lamps 39~ and 395 are disposed at the upper and left portions,respectively, on the front surface of the teaching device 359. ~len the Y- and Z-directions in which the grindstone head 219 is displaced are se].ected by the direction selection switch 373 on the control panel 357,the display lamps 392 and 395 are turned on;when the ~- and Y-directions are selected,the display lamps 393 and 394 are turned on;and when the X- and Z-directions are selected,the display lamps 393 and 395 are turned on,thereby indicating the operation direction of the __ , o p e Là t i o n handle 391.
A pair of encoders 396 and 3~7 are disposed incorres~ondance witll the operation handle 391 within the teaching device 359 and are adapted to be activated through rotating shafts and the like in response to the horizontal inclination and rotation of the operation landle 391 so as to generate the output signals for energizing the X-,Y~ and Z-direction motors 208,213 and 220 in response to the direction of rotation and the angle o rotation. In addition,a start switch 39~ for starting the teaching mode or step and a switch 399 for decelerating the displacement velocity of the grindstone head 219 are disposed on the front surface of the teaching device 359.
~ eferring next to Fig.lL, the control circuit of the grinding machine with the above-described construction will be e~plained. A central processing unit CPU 401 is connected to a read-only memory (RO~I) 402 and a random access memory ~R~) 403 ~hich constitutes a storage means. A program for controlling all the operations to be accomplished by the grinding machine is stored in ROM 402 while the data of grinding paths to be followed by the grindstone head 219 derived from the teaching device 359 in the teaching mode or step is stored in ~ 403.
The group 404 of switches on the control panel 357, the teaching device 359 and the group of overload sensors 361-365 are connected through an input interface 406 to CPU 401. In addition, CPU 401 is connected through an output interface 408 to the X-direction motor 208,the Y-direction motor 213,the Z-direction motor 220, -29-~

the air motor 238 and a display lamp group 407 consisting of the above-described display lamps on the control panel 357 and the teaching device 359 through driving circuits 409-413,respectively, so that the driving and stop signals can be trasmitted to them.
NeY.t the ~lode of operation of the grinding machine with the above-described construction will be explained.
As shown in Figs.4 and 5,the workpiece 101 such as a die is mounted on the table 225,brought to and maintained at the operation position immediately below the grindstone head 219.
In case of the teaching mode or step in which the grinding paths are taught by displacing the grindstone head 219 along the surfaces to be ground 102,103 and 104,first the teaching mode is selected by the mode selection switch 371 on the control panel 357 and then two directions ( for instance,the X- and Y-directons) in which the grindstone head 219 is displaced are selected by the direction selection switch 373.Next the displacement velocity of the grindstone head 219 is set to a desired value such as the medium displacement velocity by the velocity selection switch 377 in the teaching operation region 375. Then,the remaining time display device 379 displays the remaining time during which the data can be stored in RA~I 403 while the display lamps 393 and 394 on the teaching device 359 Are turned on to indicate the direction in which the operation handle 391 is operated.
Thereafter,in accordance with the display lamps 393 and 394 which are turned on,the operation handle 391 is leveled and rotated in the X-direction,the Y-direction or in the direction between them. Tllen in response to the direction of rotation and the angle of rotation of the operation handle 391, the encoders 396 and 397 deliver the detection signals to CPU 401 which in turn delivers the driving signals to the .~- and Y-direction motors 208 and 213 to ener~ize them. Upon energization o the motors 20S and 213,the grindstone head 21~ is displaced by a predetermined distance in the Y- and Y-directions. Concurrently,the same signals are delivered from CPU 401 to Pl~l 403 so that only the position data is stored as the data of grinding paths regardless of the tracing velocity. Thus,when the operation handle 391 is leveled and rotated while confirming the position to which is displaced the grindstone head 219, the data o~ grinding paths in the X-and Y-directions along the bottom surface 104 to be ground of the workpiece 101 can be easily stored.
Next in case of grinding the bottom surface 104 to be ground of the workpiece 101 based on the data of grinding paths thus stored, the operation or grinding mode is selected by the mode selection switch 371 on the control panel 357 and the whole grinding operation time is set by the time setting device 384 in the operation region 382. I~hen the start switch 386 is depressed under these conditions,the remaining period of time for the grinding operation step is displayed while CPU 401 reads out the data of grinding paths from R~ 403 so that in response to the data thus read out,the driving signals are delivered to the ~'- and Y-direction motors 208 and 213. As a result,both the motors 208 and 213 are energi~ed so that the grindstone head 219 is displaced in the ~-and Y-directions.
In this case, the first air cylinder 244 as shown in Fig.6 forcibly presses tlle grindstone 242 against the bottom surface 104 to be ground of the worlcpiece 101 while the air motor ~38 causes the grindstone 242 to reciprocate. As a result,the surface 104 to be ground is ground successively along the pre-determined grinding paths.The grinding operation is repeatedly carried out as the grindstone head 219 reciprocates in accordance with the data of grinding paths until a previously set period of time set by the time setting device 3~4 has elapsed. Therefore, it is not needed to indicate a grinding path for each stroke of the grindstone head 219 so that the grinding process can be carried out efficiently.
In this embodiment,during the first displace~ent of the grindstone head 219 in the grinding step,the grindstone head 219 traces the return path from the end position to the start position of the displacement of the grindstone head 219 determined in the teaching mode or step so that it is not needed to return the grindstone head 219 from the end position to the starting position of the displacement thereof after the completion of the teaching step or mode and consequently the grinding process can be much simplified. In addition, the grindstone ~2 can be positively prevented from colliding against the projections or the like on the surface to be ground which tends to occur when the grindstone head 219 is linearly returned from the end position to the starting position of the displacement thereof.

13t3308 Furthermore,in case of grinding the left or right side surface 102 or the front or rear surface 104 of the workpiece 101, the grinding path data is inputted after the two directions such as the Y- and Z-directions or Y~- and Z-directions are selected by the direction selection switcll 373 in the teaching mode or step.
Then, according to the data of grinding paths thus obtained,the grindstone 242 can easily and efficiently grind the right and left surfaces to be ground 102 and the front and rear surfaces to be ground lQ3.
I~len the grindstone 242 collides against a projection or the like on the surface to be ground in case of the teaching or grinding step so that an overload acts on the grindstone 242, one of the overload sensors 361-366 as shown in Figs 6 and 7 delivers the detection signal to CPU 401 which in turn delivers the stop signals to the ,~-,Y- and Z-direction motors 20~,213 and 220 and the air motor 338 so that the displacement of the grindstone head 2;19 and the grinding operation by the grindstone 242 can be immediately interrupted. In addition,an "erase data " signal is delivered from CYU 401 to R~ 403 so that the grinding path data stored in R~I 403 is erased Therefore,there is no danger that the grinding operation is continued by the overloaded grindstone 242 or the repetition of the grinding operation in accordance with the erroneous data of grinding paths can be avoided. Thus,the grinding process can be safely accomplished.
In the third embodiment,the reciprocal movement in the grinding step can be determined by a predetermined times of rotations 1 31 33~8 instead of the determination by a preset period of time described above.
~ eferring ne~t to Figs.12 and13 , a fourth embodiment of the present invention or a die polishing machine embodying the present invention will be described.
The frame of the die polishing machine is equipped with a supporting cylinder 501 movable in the ,~-,Y- and Z-directions and a mounting shaft 502 is securely attached to the lower end of the supporting cylinder 501. A head bloclc 503 is carried by the mounting shaft 502 in such a way that the rotation about the vertical axis of the head bloclc 503 is adjustable and is normally securely held in a predetermined position by means of a clamping lever 504. A bracket 506 is rotatably carried by the head block 503 through a horizontal shaft 505 in such a way that it can be brought to a desired angular position through a worm 508 and a worm wheel 509 by a handwheel 507 and is normally securely held at a desired position by means of a clamping lever 510. The head block 503 and the bracket 506 constitute a grindstone head 511 of the die polishing machine.
A rail 513 is disposed within the bracket 506 and slidably supports an air cylinder 516,which is biasing means,through a slider 515. The upper end of the piston rod 517 of the air cylinder 516 is securely joined to a guide member 514. A mounting ~ember 519 formed with a plurality of mounting holes 518 is securely mounted on tl~e air cylinder 516. An air motor 522,which is driving means, is supported by the mounting member 519 by bolts 520 inserted . -34-1 31 330~
through the selected mounting holes 518 ln such a way that the position of the air motor 522 can be changed. A swinging member 524 is connected through an oscillation generator 523 to the air motor 522. A
grindstone 526 is attached with a clamping screw 525 to the lower end of the swinging member 524 in such a way that the angle of inclination of the grindstone 525 can be adjusted.
In case of grinding the surface of an impression or cavity in a die 101 by the die polish-ing machine with the above-described construction, first the angular positions of the head block 503 and the bracket 506 of the grindstone head generally indicated by the reference numeral 511 are suitably adjusted so that the grindstone 526 is brought to a position in opposing relationship with a desired surface to be ground of the work 101. For instance, the head supporting cylinder 501 is so controlled to be fed in the X- and Y-directions, the grindstone head 511 is positioned as shown in Fig. 12 so that the grindstone 526 is located in opposing relation-ship with the bottom surface of the die 101. When the head supporting cylinder 501 is so controlled as to be fed in the Y- and Z-directions and when the bracket 506 is rotated in the counterclockwise direction to a position anyularly spaced apart the position shown in Fig. 12 through 90. Then the grindstone 526 is in opposing relationship with one of the side surfaces of the work 101. When the head block 503 is rotated through ~' ~ . .

90 about the vertical a~is under these conditions,the grindstone 526 is brought to a position in opposing relationship with the other side surface of the worlc 101 SO that the grindstone 526 can be fed in the ~- and Z-directions.
When the air cylinder 516 is energized after the grindstone 526 has been brought to a position in opposing relationship to the desired surface to be ground,in response to the displacement of the main body of the air cylinder 516,the grindstone 526 is pressed against the surface to be ground. The pressure applied to the grindstone 526 can be suitably adjusted by adjusting the working pressure applied to the air cylinder 516. ~len the air motor 522 is energized under these conditions,the grindstone 526 is oscillated by the oscillation generator 523 and grinds the surface to be ground. In this case,the air cylinder 516 normally presses the grindstone 526 against the surface to be ground so that it is displaced following the variations in shape of the surface to be ground. Therefore,the surface to be polished can be polished uniformly with a high d~gree of precision without causing the insufficient polishing of the recessed portions of the surface to be polished and the excessive polishing of the projected portions thereof. Furthermore,since the air cylinder 516 is disposed on the side of the grindstone 526 rather than on the side of the grindstone head 511,the vibrations of the air motor 522,the oscillation generator 523 and the grindstone 526 are damped by the air cylinder 516 so that the vibrations transmitted to the frame can be reduced to a miminum.

Fig.l3 sllows another applica~ion of the fotlrth embodiment o the present invention.An arm member 52~ is interposed bet~Jeen the grindstone llead 511 and the air cylinder 516 so that the ~rindstone 526 can be located at the deep portion of the wor}cpiece 101.
rlhnt is,a supporting arm 529 is securely attached to the heacl block 503 o~ the grindstone head 511 and tlle base end of the arm member 523 is pivotably attached ~ith a pivot pin 530 to the supporting member 529. A link 531 is interconnected between the midpoint bet~leen the ends of the arm member 52~ and the mounting hole 518 of the mounting member 519. In aclditionJ the air motor 522 having the grindstone 526 is removed from the mounting member 51~
and is mounted at the lower end of the arm member 528 with a screw 532. The force of the air cylinder 516 is transmitted through the link 531 and the arm mem~er 528 to the grinstone526 so that the latter is pressed against the surface to be ground or polished of the workpiece 101 under the force depending upon the working pressure supplied to the air cylinder 516. Tllerefore, the grindstone 526 can reach even the deepest portion of the workpiece 101 without being interrupted by the grindstone head 511 and the guide member 514 so that even the detailed portions of the surface having a complicated pattern of the workpiece 101 can be easily ground.
In the fourth embodiment,instead of the air cylinder 516 a bias spring may be used and the grindstone 526 may be directly connecred to the air motor 522 so that the surface to be ground may be ground by the rotation of the grindstone 526.
Referring next to Fig.l4,a fifth embodiment o the present invention or a die l~olislling machine emboclying tlle present invention will be describe(l.
A frame ~generally indieated by the reference numeral 601 has a gantry-lil;e constrttction having rl pair of telescopic columns S02 and a cross girder S03 and a table 604 on whicll is mounted a ~orkpiece 101 movably ride~ on a pair of rails 605 laid through the die polishing or grincling machine. An ~'-directon moving body 607 ~hich is driven by an ~-direction motor 606 is mounted on the cross girder 603 and a Y-direction moving body 609 which is driven by a Y-direction motor 60~ is mounted at the lower portion of the ~'-direetion moving body 607. A Z-direction lead screw 611 is extended downwardly througll a guide eylinder 610 seeurely mounted on the Y-direetion,moving body 609 and is driven by a Z-direetion motor 612 so that the lead screw 611 is vertieally moved.
A grindstone head 613 is mounted at the lower end of the Z-direction lead serew or shaft 611 in sueh a way that the angular position in a horizontal plane of the grindstone head 631 ean be adjusted. A braeket 615 is pivoted with a horizontal pivot pin 614 tc) the grindstone head 613 in sueh a way that its angular position in a vertieal ~lane ean be adjustecl. An air eylinder 617 is movably mounted on a guide member 616 seeurely attached to the braeket 615 and its piston rod 61~ is seeurely joined to the guide member 616. An air motor 619,which is driving means,seeurely mountecl through a mounting meTnber 622 on the air cylinder 617 and is drivingly eoupled through an oseillation generator 620 to a swinging member 621.
A grindstone 624 is connected to the swin~ing member 621 with a 3~-screw 623 in such a way that the angular position of tlle ~rindstone 624 can be adjusted. l`he grinclstone 624 is pressed against the surface to be ground of the worlcpiece 101 under the force of the air cylinder 617. I~hen the air motor 619 is energized under these conditions, the grindstone 624 is forced to slide through the oscillation generator 620,thereby grinding the surfaces of an impression or cavity in the workpiece lOl.
In the fifth embodiment,the braclcet 615,the guide member 616 and the mounting member 622 constitute a mounting assembly.
Therefore the grindstone 624 grinds the surface to be ground of the workpiece 101 at an eccentric position with respect to the axis o~ the lead screw or shaft 611 supporting the grindstone head 613. As a result,even ~hen the Z-direction lead screw or shaft 611 is extended longer do~nwardly,the vibrations caused by the rotation of the air motor 619 and the sliding motion of the grindstone 624 can be damped by a plurality of component parts interposed between the grindstone 624 and the grindstone head 613 so that impacts actlng on the moving bodies 607 and 609 and the frame 601 can be reduced to a minimum.Furthermore,since the position of the grindstone 624 is spaced apart from the extension of the axis of the Z-direction lead screw or shaft 611 in the horizontal direction by a suitable distance,there exists no danger that a very great oscillation momement due to the single harmonic motion acts on the side of the frame 601. Therefore,the constructions of the moving bodies 607 and 609 and the frame 601 can be simplified.
In the fifth embodiment,the component parts of the mounting assembly can be suitably increased or decreased in number. Furthermore, the grindstone 624 can be directly connected to the alr motor 619 so that the surface to be ground is ground by the rotation of the grindstone 624. In addition,the air motor 619 may be mounted on the frame 601 and be drivingly coupled to the oscillation generator 620 through a suita~le power tansmission mechanism using a wire so that the surface to be ground is ground.
Referring next to Figs.15-18,a sixth embodiment of the present invention will be described.
As best shown in Fig.17,a grinding tool 723 is detachably mounted at the leading end of a driving shaft 722 of an air motor 721 and is pressed against the surface to be ground of a wor~piece 101 by an air cylinder 71~.
As shown in Fig.15,a ball member 725 is formed integ~ally with the leading end of a mounting shaft 724 of the grinding tool 723 and a pair of engaging projections 726 whose axes are per-pendicular to the axis of the mounting shaft 724 are extended radially outwardly from the center portion of the ball member 725 in a symmetric relationship with each other with resect to the center of the ball member 725 in order to transmit the rotation.
A socket 72~ for receiving therein the ball member 725 is formed on the upper surface of a mounting member 727 of the grinding tool 723. The socket 72~ is formed with a pair of engaging grooves 729 in diametrically opposing relationship with each other.
The engaging projections 726 are slida~ly fitted into and guided by tlle engaging grooves 729,respectively. The inner bottom of the soc1;et 72~ is formed with a supporting recess 730 extended downwardly toward the lower surface of the mounting member 727. The supporting recess 730 is made intocon~act with a portion of the spherical surface of the ball memher 725 so that the relative rotation between the ball member 725 and the supporting recess730 is permitted in the direction in which is inclined the mounting shaft 724.
A flat circular rubber cushion member 731 is securely joined to the undersurface of the mounting member 727 and an abrasive stone 732 consisting of a sheet of diamond paper is securely joined to the undersurface of the cushion member 731. The abrasive stone 732 consists of a cloth base 733 and a plurality of partially helical abrasive layers 734 consisting of bonded synthetic diamond abrasive grains. ~ach abrasive layer 734 is formed witll a discharge surface 734a for discharging the dislodged grains and chips which is curve~ backwardly with respect to the direction of rotation of the grindstone.
I~en the air motor 721 is energiæed while the grindstone 732 is made into contact with a surface to be ground, the grind stone 732 is made into intimate contact with a wide contact portion of the forming surface of the workpiece 101 regardless of its pattern withollt leaving any non-contact portion and is rotated.
Therefore,the grinding efficiency is improved and the chips are discharged along the discharge surfaces 734a when the grindstone 732 is rotated. In addition,the abrasive stone 732 can be rotated between the position indicated by the solid lines and the position indicated by the two~dot chain lines as shown in Fig.15 ,following the projections and recesses of the surface to be ground of the workpiece 101 so t~lat the grinding operation can be carried out smoothly and that it is not needed to change the angle of inclination of the mounting shaft 724.
Because of the provision of the bracket 716,the guide member 717 and the mounting member 7ZO,the grindstone 732 grinds the surface to be ground of the workpiece 101 at a position eccentric to the a~is of the grindstone head 714 and the Z~direction lead screw or shaft 712. Therefore even when the Z-direction lead screw or shaft is extended longer downwardly,vibrations caused by the rotation of the air motor and the grinding tool 723 in the grinding operation are damped by a plurality of component parts interposed between the grindstone 732 and the grindstone head 714. As a result,impacts which act on the moving bodies 707 and 709 and the frame 702 can be reduced to a minimum.
In the grinding tool 723 of the sixth embodiment,the leading end of the mounting shaft 727 is terminated into the ball member 725 and the mounting member 727 on whicll is mounted the grindstone 732 such as diamond paper is provied with tlle socket 728 for receiving tllerein the ball member 725. The inner bottom surface of the socket 728 is formed with the supporting recess 730 which is made into contact with a portion of the spherical surface of the ball member 725 to support the same. Therefore,the supporting recess 730 upon which acts the pressing force so as to press the grindstone 732 against the forming surface of the workpiece 101 can be formed in close pro~imity of the grindstone 732.As a result.

the force for causing the grindstone 732 to move away from the surface being ground oi the worl;piece 101 ~hich is caused when the axis of tlle mounting shaft 724 intersects that of the mounting member 727 and the centrifugal force procluced upon rotation of the mounting member 727 can be reduced to a miminum. Consequently, the movement oE tlle grindstone 732 away from the surface to be ground of the workpiece 101 can be almost prevented so that the ability of the grindstone 732 to follow the pattern of the surface to be ground of the wor~piece 101 is improved and therefore the smooth grinding operation can be ensured.
In the grinding tool 723 of the sixth embodiment,the distance between the supporting recess 730 of the mounting member 727 and the grindstone 727 is shortened so that the diameter of the mounting member 732 can be decreased correspondingly. Therefore, the grindstone 732 can easily follow the projections and recesses each having a small curvature of radius of the surface to be ground of the workpiece lOl so that the uniform grinding operation can be ensured.
In addition,as compared with the relatedart grinding tools, the grinding tool 723 of the sixth embodiment has a less number of component parts and therefore is simplified in construction and asse~bly.
T~e sixth embodiment described abvoe can be modified as follows:
(1) As best shown in Fig.l~,the cushion member 731 can be eliminated and the mounting member 727 is made in the form of a flat plate.

And the ~rindstone 732 is directly joined to the undersurface of the flat-plate-lilce mountin~ member 727.
(2) The air mo~or 721 can be mounted,for instance,on the frame 702 so as to drive tlle driving shaft 722 through a power transmission mechaism using a wire,thereby grinding the surface to be ground.
(3) The grindstone 732 can be made in the form of a flat plate.
(4) The grinding layer 734 of the grindstone 732 can be arranged ill the form of a spiral in a flat plane.
(5) The mounting member 727 and the socket 728 can be made of a hard synthetic resin and anti-abrasion sheet metal can be disposed in the engaging grooves 729 and the supporting recess 730,whereby the grinding tool can be made light in weight.
Y~eferrîng neY~t to Figs.19-25,a seventh embodiment of the present invention will be described below.
As shown in Figs.l9 and 21,a grindstone head 814 consisting of a head block 815 and a bracket 816 is attached through a rotary mechanism 817 to the lower end of a shaft 812 which can be displaced in the Z-direction ( to be referred to as " the Z-direction shaft "
for brevity hereinafter in this specification).The grindstone head 814 i5 rotatable about the axis of the Z-direction shaft 812 in unison with the rotary mechanism 817.The rotary mechanism 817 is composed of a servomotor 819 mounted on one side of a casing 818,a worm 821 securely carried by an output shaft 820 of the servomotor 819 and a worm wheel 823 carried by a supporting rod 822 extended downwardly from the lower end of the Z-direction shaft 812. The rotary mechanism 817 can be rotated from its initial position indicated in Fig.19 through 360 in both the clockwise and counter-clocwise directions. As best shown in Fig.21 ,a rotary encoder 824 for detecting the angle of rotation of the output shaft 820 is mounted on the casing 818. The head block 815 is disposed in such a way that its angular position in a horizontal plane can be adjusted with respect to the rotary mechanism 817.
As shown in Fig. 21,the bracket ol6 has a pair of supporting plates 816a and 816b between which is clamped the head block 815 and is rotatable about a horizontal shaft 825 in such a way that its angular position in a vertical plane can be adjusted suitably.
The bracket 816 is securely held in a desired position by means of a clamping lever 827 which is extended through an elongated hole 826 formed through the supporting plate 816a and is made into threadable engagement with the head block ~815. A guide member 828 with a rail 829 is securely attached to the bracket 816. A first air cylinder 831 is movably supported through a slider 830 by the rail 82~ and its piston rod 832 is securely connected to the guide member 828. An air motor 835,which is a driving means, is colmected through a ~olt 834 to a mounting member 833 which in turn is securely attached to the air cylinder 831. A grindstone 838 is rotatably attached through a mounting sha~t 837 to the driving shaft 836 of the air motor 835.
The grindstone 838 may be swingably connected through an oscillation generator 853 or 854 as shown in Fig.23 or 24~
respectively,to the air motor 835. In this case,the grindstone 838 is used to cut longitudinal grooves in order to facilitate to finish the surface to be ground of a forming die and to draw a formed product out of the die.
As shown in Figs.19 and 21, a mounting plate 839 is disposed on the other supporting plate 816b of the bracket 816 and is made into intimate contact therewith in such a way that it is rotatable about the horizontal shaft 825 and its angular position can be adjusted.
~he mounting plate 839 is securely held at a desired position by the coaction between a spacer 842 and a clamping lever 840 which is extended through an elongated hole 841 of the mounting plate 839 and is threadably engaged with the head block 815 when the clamping lever 840 is rotated.
A supporting arm 843 is extended outwardly from the outer side at the upper portion of the mounting member 839. A
second air cylinder S45 whicll rotates the bracket 816 so as to press the grindstone 838 against the surface to be ground of the workpiece lOl is rotatably supported by a shaft 846 between a pair of upright bearing members ~44 e~tended upwardly from the upper surface of the supporting arm 843. The leading end of the piston rod 847 of the air cylinder 845 is pivotably connected through a connecting member ~48 to the guide member o28. The bracket 816 becomes rotatable when tlle clamping lever 827 is loosened while the mounting plate 839 is securely held in position by the clamping lever 840. T~7hen the second air cylinder 845 is energized so that its piston rod 847 is extended,the bracket 816 is rotated from the position indicated by the solid lines to an inclined position indicated by the two-dot chain lines in Fig. 19. Both of the cylinders 831, 845 are controlled by the circuit as shown in Fig. 8.

~3~3308 In case o~ grinding the surface 105 (in the ~orm of an ellipse as shown in Fig.22 ) of a vertical recess in a workpiece lOl as shown in Fig.20 with the die grinding machine with the above-described construction,the angular position of the bracket ~16 of the abrasive stone head 814 is so adjusted that the axis of the guide member ~2~ is perpendicular to the axis of the Z-direction shaft &12. And the bracket ~16 is securely held in position by the clamping lever ~27 so that the abrasive stone 83~ is in opposed relationship with the surface to be ground 105 on the left side of the work 101. ~len the switch on the control panel ~49 is actuated under tllese conditions, the first air cylinder o31 is energized. As a result,the grindstone ~3~ is pressed against the surface to be ground 105 at a predetermined pressure by the first air cylinder ~31.
I~hen the air ~notor ~35 is energized Imder these conditions, the grindstone ~3~ is rotated while the grindstone head ~14 is moved upwardly anc~ do~m~ardly so that a portion of the curved surface to be ground 105 is ground in a predetermined width in the vertical direction.Thereafter the grindstone head ol4 is displaced downwardly a~d rightwardly in Fig.22 and is slightly rotated _4~_ stepwise by the servomotor 8l9 so that the surface to be ground 105 continuous with the ground surface ls ground successively. At the corner portions shown in Fig.22, the grindstone head 814 is rotated as indicated by the two-dot chain lines by the servomotor 819. Therefore the grindstone or abrasive stone 838 is disposed `:~
in opposing relationship with the surface to be ground lOS so that the cuFved surface to be ground 105 is contlnuously ground.

:` :

In the case of`;grinding the surface to be ground 106, the clamping lever 827~is Loosened to permit the rotation of the ~ bracket 816 while the mounting plate 839 is securely clamped ~
- ~ by the clamping lever 840. When a switch on the control panel 849 is actuated under these conditions, ~ the first ànd second air cylinders 831 and 845 are energized. Then :~ .
- the bracket 816 is rotated and located at the inclined position " ~: : ;
- ~ -48--: ' .
:`' as indicated by the two-dot chain lines in Fig.lg by the second air cylinder 845 while the grinAstone 837 is displaced along the bracket ~16 by the first air cylinder ~31. Thus,the grindstone or abrasive stone 33~ is pressed against the surface to be ground 105 under the combined force o~ both of the first and second air cylinders 831 and 845 at a predetermined pressure.
~ len the air motor ~35 is energized under these conditions, the grindstone $38 is rotated while the grindstone head ~14 is displaced not only in the right and left directions but also in the vertical direction. As a result,a predetermined width of a portion or the surface to be ground 106 is ground. Thereafter the grindstone head 814 is moved downward and rightwa~d:in Fig. 22 and the grindstone head 814 is rotated by the servomotor ~19. Therefore the grindstone or abrasive stone ~3~ is positioned in opposing relationship with the surface to be ground 106 so as to continuously grinde the same.
In case of grinding a flat surface to be ground 107, two directions;that is,the longitudinal direc~ion ( the forward and baclcward directions) and the vertical direction are selected as the directions in which rhe grindstone head 814 is displaced.Thereafter, the bracket 816 is brought to the position indicated by the solid lines in Fig.l9 and is securely held in position. Ne~t as in case of grinding the surface 105,the first air cylinder 831 is energized so that the abrasive stone 814 is displaced not only in the transverse direction but also the longitudinal direction ( perpendicular to the paper of Fig.21),thereby grinding the bottom surface 107.

_49_ In case of grinding the surfaces to be ground of a workpiece lOl as shown in Fig.23 with the die grinding machine witll the above-described construction,first the clamping lever 827 is loosened to permit the rotation of the bracket 816. In case of grinding tlle bottom surface to be ground 104 of the workpiece 101, two directions;that is,the transverse direction and the longitudinal direction are selected by actuating a switch on the control panel 849 as the directions in which the abrasive stone head 814 is displaced. Then both the first and second air cylinders 831 and 845 are energized.Therefore the bracket 816 is rotated to the position indicated by the solid lines in Fig.l9 by the second air cylinder 845 while the abrasive stone 838 is displaced along the bracket 816 in the downward direction by the first air cylinder 831 and is pressed against the surface to be ground 104 at a predetermined pressure.
In this case, a small force is exerted from the second air cylinder 845 to the surface to be ground 104 so that the guide member 82$ tends to rotate in the countercloc~wise direction about the horizontal shaft 825.
~ len the air motor 835 is energized under these conditions, the abrasive stone 838 is rotated and when the ~- and Y-direction motors 808 and 810 are energized,the abrasive stone head 814 is arbitarily displaced in the transverse and longitudinal directions so that the surface 104 is ground.

~ lext in the case of grinding the right or left side surface to be ground 102 of the workpiece 101,the longitudinal and vertical directions are selected as the directions in which tlle abrasive stone head 814 is displaced.Furthermore,the second air cylinder 845 is energized so that the piston rod 847 is extended, thereby rotating the guide member 828 to the position at which the axis of the gulde member 828 becomes perpendicular to the axis of the Z-direction shaft 812. Thereafter the first air cylinder 831 is energized so that the grindstone 838 is pressed against the surface to be ground 102 at a predetermined pressure. ~1hen the air motor 835 is energized under these conditions,the grindstone 838 is rotated while the abrasive stone head 814 is arbitarily displaced in the longitudinal and vertical directions in Fig.23 so that the abrasive stone 838 grinds the surface 102 to be ground.
In case of grinding the foward or backward surface to be ground 103 of the workpiece 101,the transverse and vertical directions are selected as the directions in which the abrasive stone head 814 is displaced. The grindstone head 814 is then rotated through 90 from the position indicated in Fig. 23 and securely held in position by the clamping lever 852. Thereafter the second air cylinder 845 is energized so that the piston rod 847 is extended to rotate the guide member 828 to a pOSitiOII at which the axis of the guide member 828 becomes perpendicular to the axis of the Z-direction shaft 812.
Then the first air cylinder 831 forces the grindstone 838 to press against the surface to be ground 102 at a predetermined pressure.
~en the air motor 835 is energized,the abrasive stone 838 is rotated ~ - , while the grindstone head 814 is displaced in the transverse and vertical directions in Fig.23 so that the abrasive stone o38 grinds the surface 103.
In case of grinding the surfaces 108 merging between the suri'aces to be ground 102,103 and 104 of the workpiece lOl,the longitudinal and vertical directions in Fig.23 are seelected as two directions in which the grindstone head 814 is displaced. Next the second air cylinder 845 is energized so that the guide member 828 is rotated to the inclined position indicated by the two-dot chain lines in Fig.l~. lhen the first and second air cylinders 831 and 845 coact to force the grindstone 838 to press against the surface to be ground 108 at a predetermined pressure. I~hen the air motor 835 is energi~ed,the grindstone 838 is rotated while the piston rod o46 of the second air cylinder 845 is extended and retracted. Concurrently,the abrasive stone head 814 is displaced in the longitudinal and vertical directions so that the abrasive stone 838 grinds the surface 108.
I~en all the surfaces of the work 101 have been ground by the rotary abrasive stone 838,the air motor 835 and the abrasive stone 838 are removed from the mounting member 833 and then the att~t as shown in Fig.24 or 25 is attached to the attachment member 833 so that the abrasive stone 838 is forced to oscillate to finish the surfaces to be ground 102,103,104 and 108 and cut logitudinal ~grooves therein.
In the seventh embodiment,the first and second air cylinders 831 and 845 coact to force the grindstone 838 to normally press against the surEace to be ground of the workpiece 101 at a predetermined pressure. Therefore,the ~rindstone ~38 can be displaced smoothly, following the variations in shape of the surface to be ground.
As a result,the grindstone $38 can grind the surface to be grolmd uniformly and with a high degree of accuracy without causing the non-uniform grinding such as the insufficient grinding of the recessed portions and the excessive grinding of the projected portions on the surface to be ground.Furthermore,the non-uniform contact of the abrasive stone 848 with the surface to be ground can be avoided.
In the seventh embodiment,the rotary mechanism 817 which rotates the abrasive stone head 814 about the axis of the Z-direction shaft 812 can be rotated in unison with the abrasive stone head ~14 so that the interference between the second air cylinder 845 and the rotary mechanism 817 due to the rotation of tlle head block 815 can be avoided.
In the senventh embodiment,the grinding of tlle surfaces to be ground 105 and 107 of the workpiece 101 can be accomplished while the bracket ~16 is maintained in the rotatable s~ate as in the case of grinding the surface 106.

As described above,according to the seventh embodiment of the present invention,the abrasive stone head can rotate about the axis of the Z-direction shaft through the rotary mechanism so that in the cases of grinding a pluraity of vertically ex.tended surfaces to be ground of a workpiece,the operation for changing the attachment state of t~e grindstone with respect to the abrasive stone head by an operator can be eliminated and consequently the efficiency of the grinding operation can be improved. Especially,the seventh embodiment has an excellent feature that it can grind uniformly and with a high degree of accuracy a plurality of curved surfaces to be ground which merge with each other.
ile~t referring to Figs.26-28,an eighth embodiment of the present invention will be described.
As shown in Fig. 26,an X-direction moving body 902 is mounted on a frame 901 of a die polishing machine and is displaced in the transversedirection ~ the right and left directions) by an X-direction driving motor 903. A Y~direction moving body 904 is mounted on the X-direction moving body 902 and is displaced in the longitudinal direction ( forward and backward directions) by an Y-direction motor 905. A Z-direction moving body 906 is mounted on the Y-direction moving body 904and displaced vertically by a Z-direction driving motor 907 and an abrasive stone 909 is attached througll an abrasive-stone driving motor 908 to the lower end of the Z-direction moving body 906. Upon rotation of the driving motor 908,the abrasive stone 909 is forced to oscillate or rotate,thereby grinding selectively an ~-Y surface to be ground 911,an XZ surface to be ground 912 and a Y-Z surface to be ground 913 of a forming di,e 910.
A control panel 914 mounted on the frame 901 is connected _54_ through a cable 915 to a portable remote-controlled teaclling device 916. The teachig device 916 i5 provided with an operation or joy stick 917 whicll can be inclined and rotated through 360.
The direction of inclination and the angle of inclination of the operation or joy stick 917 are detected by a combined signal from a first and a second shaft encoders 918 and 919 incorporated in the teaching device 916 ( See Fig.28). The teaching device 916 is further provided with an input plate 920 and a correction switch 921 which is a correction means activated when the abrasive stone 909 follows an erroneous grinding path.
As shown in Fig.28,the input plate 920 is provided with a mode selection switch 922 ~or selecting the manual operation mode,the teaching mode or the playback mode,a surface selection switch 923 for selecting the X-Y surface 911,the ,Y-Z surface 912 or the Y-Z surface 913,a start switch 924 for starting the teaching or playback mode,an end switch 925 for interrupting each mode and a di~play device (not shown) for indicating a selected surface to be ground or polished.
These switches 921-925 and the encoders 910 and 919 are connected to the input side of a central processing unit CPU 926 incorporated in the teaching device 916 and the display device is connected to the output side thereof. The output terminal of CPU g26 is connected to a CPU 927 incorporated in the control panel 914 and the data signal is transmitted between CPUs 926 and 927.
Referring still to Fig.28, the control panel 914 is provided _55_ with a start switch 924A for starting the teaching or playbacl;
mode, an end SWitClI 925A for interrupting each mode and a display device (not sllown) ~or displaying various operation steps sucII as the teaclIi2lg mode.
The switches 924A and 925A are connected to the input side of CPU g27 and the xr- ~ Y- and Z-direction motors 903,905 and 907 and the abrasive-stone driving motor 90~ are connected to the outoput side of CPU 927 and the drive and stop signals are transmitted from CPIJ 927 to these motors. Furthermore,CPU 927 is connected to ROI~I 92~ which stores a program for controlling all steps carried out by the die polishing machine and to R~l 929 for storing the data o~ grinding paths of the abrasive stone 909 which can be reprogrammed as often as desired.
l~ext the teaching mode of the die polishing machine with the above-described construction will be described. First in case of teaclling the grinding paths, tlle teaching mode is selected by the mode selection switch 922 on the teaching device 916. Then,for instance,the X-Y surface to ~e ground 911 is selected by the surface selection switch 923 so that the direction of the displacement of the abrasive stone 909 is limited only in the Y~-and Y-directions.
Thereafter,when the operating or joy stick 917 is inclined in a desired direction,the detection signals representative of the direction of inclination and the angle of inclination,respectively, are delivered from the encoders 918 and 919 to CPU 926 and then transmitted to CPU 927 which in turn delivers the drive signals to ~.

the ~- and Y-direction motors 903 and 905,respectively. Upon rotation of the motors 903 and 905,the abrasive stone 909 is displaced along a desired grinding path in either the hr- or Y-direction and this grinding path is stored in I~AM 929.
I~lhen the abrasive stone 309 is displaced along an erroneous grinding path 109 as shown in Fig.27 and wllen the correction switch 921 is depressed when the abrasive stone 909 is at a point 110, CPU 926 delivers the signal to CPU 927. Then CPU 927 reads out the grinding path data stored in P~l 929 in the reversed direction and delivers the reverse signals to the ,~- and Y-direction motors 903 and 905. Then,the abrasive stone 909 is automatically reversed to a desired grinding path 112 along the erroneous grinding path 109 from the point 110. When the abrasive stone 909 is returned to a point 111 on the desired grinding path 112,the correction switch 921 is released. Then,CPU 927 specifies the data of the return path from the pointl10 to the pointlll as an erroneous data and then erases this erroneous data. Therefore,the abrasive stone 909 can be returned to a point of a desired grinding path from which the abrasive stone 909 has traced the erroneous grinding path and then the teaching mode can be continued smoothly without any interruption.
When the playback mode is selected by the mode selection switch 922 after the teaching mode has been accomplished,in response to the depression of the start switch 924,the data of the desired grinding paths which has been stored in RA~I 929 in the teaching mode is read out. In response to the read-out data,the ~- and Y-direction motors 903 and 905 are energi~ed so that the abrasive stone 909 are displaced along the desired paths on the ~-Y surface to be ground 911 for a predetermined number of times or a for a predetermined length of time,whereby the die 910 is automatically ground by the oscillation or rotation of the abrasive stone 909.
In the eigtll embodiment,a large number of input switches 921-925 can be easily connected to CPU 926 incorporated in the teaching device 916. Furthermore, if ado~ted a serial transmission of the data signal between CPU 926 and CPU 927 incorporated in the control panel 914,the number of cables 915 can be decreased so that the cables 915 can be made light in weight. As a result, the remote-controllability of a large-sized die polishinig machine can be especially improved. Instead of the teaching device 916, it is possible to use a wireless controller.
Furthermore,the erasure of the erroneous grinding path can be accomplished when the abrasive stone 909 is automatically retruned along the erroneous grinding path 109 to the desired gringing path 112.
As described above,according to the eigth embodiment of the present invention,when the abrasive stone is displaced along an erroneous grinding path,the data of such erroneous grinding path can be erased in storage means so that it is not needed to start the teaching mode again from the initial point. ~urthermore, there are no dangers that the grinding time is wasted in the playback mode and that the ground surEace is varied in surface roughness due to the excessive grinding of the erroneous grinding path.In _58_ the case of the displacement of the abrasive stone along an erroneous grinding path,it can be returned along the erroneous grinding path to the desired grinding path by actuating the correction means. Therefore the abrasive stone can be re-positioned again at a point on a desired grinding path from which the abrasive stone has been displaced along the erroneous grinding path and then the teaching mode can be continued again smoothly from the returned point without any interruption. ~oreover,the abrasive stone can be automatically returned to the desired grinding path in response to the actuation of the correction means so that the correction step can be accomplished easily and quickly.
It will be appreciated by those skilled in the art that variations,alternations and/ or modifications may be resotred to without departing from the spirit of the present invention and the present invention is not restricted to the above-described embodiments and may be practiced otherwise than specifically described within the scope of the following claims.

Claims (36)

1. A grinding apparatus for processing a first surface of a workpiece and a second surface of said workpiece, said second surface intersecting said first surface, said apparatus comprising:
a frame including a pair of supports standing in opposing relation to each other and a support frame which is stretched between and secured to the respective upper end portions of said supports;
first moving means provided on said support frame in such a manner that said first moving means is reciprocatable in a first horizontal direction;
second moving means provided on said first moving means in such a manner that said second moving means is reciprocatable in a second horizontal direction which intersects the first horizontal direction at right angles;
third moving means provided on said second moving means in such a manner that said third moving means is reciprocatable in the vertical direction;
a wheel head having a longitudinal axis, said wheel head being provided on said third moving means to be movable in the vertical direction;
grinding means provided on said wheel head for performing a grinding operation on said first and second surfaces of said workpiece;
first pressing means operatively connected between said third moving means and said wheel head to urge said wheel head in the direction of the longitudinal axis thereof toward said first surface of said workpiece so that said grinding means is pressed against said first surface of said workpiece while performing the grinding operation; and second pressing means operatively con-nected between said third moving means and said wheel head to urge said wheel head in a direction inter-secting the direction of the longitudinal axis of said wheel head toward said second surface of said workpiece so that said grinding means is pressed against said second surface of said workpiece while performing the grinding operation, said apparatus further comprising control means operatively connected with and controlling said first and second pressing means so that, when two directions among three directions are selected as directions of movement of said grinding means, at least one of said first and second pressing means presses said grinding means against said surfaces of said workpiece in the remaining one of said three directions with a predetermined pressure.
2. A grinding apparatus according to claim 1, wherein a table for supporting the workpiece in the area between said supports is provided so as to be movable to the area between said supports.
3. A grinding apparatus according to claim 1, wherein each of said supports comprises a fixed tube and a movable tube which is slidably fitted to said fixed tube and which is vertically movable by drive means.
4. A grinding apparatus according to claim 1, wherein first rotating means is provided between said second moving means and said third moving means so that said third moving means is rotatable about an axis which extends in the direction of movement of said second moving means.
5. A grinding apparatus according to claim 4, wherein second rotating means is provided between said first rotating means and said third moving means so that said third moving means is rotatable about a horizontal axis which intersects at right angles the axis extending in the direction of movement of said second moving means.
6. A grinding apparatus according to claim 1, wherein said first pressing means is provided between a guide support bar attached to the lower end of said third moving means and a slide member which is provided on said support bar in such a manner that said slide member is slidable in the longitudinal direction of said support bar; and said second pressing means is provided between said slide member and a support arm which is pivotally provided on said slide member through a shaft which extends in the direction of movement of said first moving means.
7. A grinding apparatus according to claim 6, wherein a control circuit is connected to a first air cylinder and a second air cylinder, said control circuit including switching valves for switching these air cylinders from an operative state to an inoperative state and vice versa.
8. A grinding apparatus according to claim 6, wherein an air motor for driving the grinding means is provided between said support arm and said grind-ing means, and an overload sensor is provided outside said air motor, said sensor being adapted to detect abnormal approach of said support arm during machin-ing of a processed surface of the workpiece which faces in the direction of movement of said third moving means and to thereby detect generation of an overload acting on said support arm.
9. A grinding apparatus according to claim 6, wherein said first pressing means comprises an air cylinder mounted on said slide member, and a piston rod having its distal end secured to said third moving means.
10. A grinding apparatus according to claim 9, wherein a pair of first overload sensors are provided inside said air cylinder at both its ends, respectively, said first overload sensors being adapted to detect abnormal approach of a piston during machining of a processed surface of the workpiece which faces in the direction of movement of said third moving means and to thereby detect an overload acting on said grinding means.
11. A grinding apparatus according to claim 6, wherein said second pressing means comprises an air cylinder which is pivotally mounted on said slide member through a shaft extending horizontally, and a piston rod having its distal end secured to said support arm.
12. A grinding apparatus according to claim 11, wherein a pair of second overload sensors are provided inside said air cylinder at both its ends, respectively, said second overload sensors being adapted to detect abnormal approach of a piston during machining of processed surfaces of the work-piece which face in the directions of movement of said first and second moving means, respectively, and to thereby detect an overload acting on said grinding means.
13. A grinding apparatus according to claim 11, wherein said slide member is provided with a stopper on the side thereof which faces said second pressing means, said stopper being adapted to limit the pivoting of said support arm.
14. A grinding apparatus according to claim 13, wherein said slide member is further provided with a support member for receiving said stopper, said support member being provided therein with a fourth overload sensor adapted to detect abnormal withdrawal of said stopper during machining of a processed surface of the workpiece which faces in the direction of movement of said third moving means and to thereby detect generation of an overload acting on said support arm.
15. A grinding apparatus according to claim 6, wherein said third moving means has a moving shaft at its lower end, and rotating means is provided between said moving shaft and said wheel head, said wheel head being rotatable together with said rota-ting means about the axis of said moving shaft.
16. A grinding apparatus according to claim 15, wherein said rotating means comprises a casing mounted on said moving shaft, a servomotor provided on one side of said casing, a worm provided inside said casing and rotated by said servomotor, and a worm wheel provided at the lower end of said moving shaft and engaged with said worm.
17. A grinding apparatus according to claim 16, wherein said casing is further provided with a rotary encoder which detects an angle of rotation of said worm.
18. A grinding apparatus according to claim 15, wherein said first and second pressing means include a bracket pivotally attached through a horizontally extending shaft to a head block which is mounted on said third moving means, said first pressing means being mounted on said bracket and adapted to move said grinding means in a direction parallel to said bracket and to thereby press said grinding means against a processed surface of the workpiece with a predetermined pressure, said second pressing means being mounted between said head block and said bracket and being adapted to pivot said bracket and to thereby press said grinding means against a processed surface of the workpiece in the direction of pivoting of said bracket with a predetermined pressure.
19. A grinding apparatus according to claim 18, wherein said first and second pressing means are first and second air cylinders, respectively, and drive means for activating said grinding means to perform a grinding motion is provided between said first air cylinder and said grinding means.
20. A grinding apparatus according to claim 19, wherein said drive means is detachable with respect to said wheel head together with said grind-ing means.
21. A grinding apparatus according to claim 20, wherein each of said first air cylinder and said second air cylinder is provided with a pressure regulating mechanism for regulating the amount of supply of a fluid, said pressure regulating mechanism being provided on said wheel head or on the side of said third moving means which is in the vicinity of said wheel head.
22. A grinding apparatus according to claim 21, wherein said pressure regulating mechanism comprises a pressure regulating valve and a pressure gauge.
23. A grinding apparatus according to claim 22, wherein said pressure regulating mechanism is provided on a mounting ring which is rotatably fitted on the lower end of said third moving means.
24. A grinding method comprising the steps of (a) teaching the desired grinding paths by displacing an abrasive stone along surfaces of a workpiece to be ground, with a teaching means and storing said desired grinding paths in a storage means independently of the displacement velocity; and (b) repeatedly reciprocating said abrasive stone within a predetermined range following said desired grinding paths stored in said storage means.
25. A grinding method as set forth in claim 24, wherein a first displacement of said abrasive stone follows a return path of the desired grinding path from an end position to a start position of the displacement of said abrasive stone in step (a).
26. A grinding method as set forth in claim 24, wherein when said abrasive stone is displaced along an erroneous grinding path in said step (a), a correction means is actuated so that said abrasive stone is reversed in direction along said erroneous grinding path and is automatically returned to said desired grinding path; and the data concerning said erroneous grinding path is erased from said storage means.
27. A grinding method as set forth in claim 24, wherein said teaching step (a) comprises the steps of selecting the mode by a mode selection switch on a control panel electrically connected to said teaching means; selecting by a direction selection switch on said control panel two of a first horizontal direction, a second horizontal direction perpendicular to said first horizontal direction and a third vertical direction as the directions in which an abrasive stonehead carrying said abrasive stone is displaced; and setting by a velocity setting switch on said control panel the displacement velocity of said abrasive stonehead.
28. A grinding method as set forth in claim 27, wherein said teaching means and said control panel are electrically connected to a control circuit which controls said respective steps and incorporates therein said storage means; a remaining period of time for permitting the storage of the data by said control circuit in said step (a) is displayed on a remaining time display device; and display lamps which are mounted on said teaching means are turned on; and the operation direction in which said abrasive stone is displaced by manipulating an operation handle disposed on said teaching means and the path of displacement of said abrasive stonehead is stored in said control circuit is indicated.
29. A grinding method as set forth in claim 24, wherein a control circuit which controls said respective steps and incorporates therein said storage means is electrically interconnected between said teaching means and said abrasive stone; overload sensors are provided to detect the overload acting on said abrasive stone and deliver the output signal representative of the overloaded abrasive stone to said control circuit; and when said abrasive stone is overloaded in each of said steps, its grinding operation is interrupted through said overload sensors and said control circuit; and the data of the grinding path stored in said storage means is erased.
30. A grinding method for grinding a workpiece comprising a teaching step in which a predetermined grinding path is profiled by teaching means and the grinding path alone is stored in memory means irrespective of the profiling speed; and a machining step in which a grindstone is repeatedly reciprocated only within a range designated in advance in accord-ance with said grinding path stored in said memory means.
31. A grinding method according to claim 30, wherein first movement of said grindstone in said machining step starts from a movement terminating position towards a movement starting position of said grindstone in said teaching step, such that the grinding path in said teaching step is followed reversely.
32. A grinding method according to claim 30, wherein said teaching step further includes the step in which, when said grindstone is moved along an erroneous path, correcting means is actuated to move said grindstone along said erroneous path reversely, thereby automatically returning said grindstone to said grinding path; and a step of erasing the data concerning said erroneous path from said memory means at the same time as said returning step is carried out.
33. A grinding method according to claim 30, wherein the teaching step includes the step of selecting the teaching mode using a mode selecting switch provided on a control board electrically connected to said teaching means; the step of select-ing two directions from the three directions, namely, a first horizontal direction, a second horizontal direction intersecting said first direction at right angles, and a third direction which extends verti-cally, as directions of movement of a wheel head supporting said grindstone by actuating a direction selecting switch provided on said control board; and the step of setting a speed of movement of said wheel head by actuating a speed setting switch provided on said control board.
34. A grinding method according to claim 33, in which a control circuit which has said memory means and controls each of said steps is electrically connected to said teaching means and said control board, so that, in said teaching step, a remaining period of time for which data can be stored in said control circuit is indicated on a remaining time indicating section provided on said control board, and indicating lamps provided on said teaching means are turned on to designate directions in which an operating handle for moving said wheel head which is provided on said teaching means may be actuated.
35. A grinding method according to claim 30, wherein a control circuit which has said memory means and controls each of said steps is electrically connected between said teaching means and said grindstone, and there is also provided an overload sensor which detects an overload acting on said grindstone and outputs a signal to said control circuit, so that, when an overload is applied to said grindstone in each of said steps, the operation of said grindstone is suspended through said overload sensor and said control circuit and the grinding path data stored in said memory means is erased.
36. A grinding method according to claim 30, wherein the teaching step comprises moving said grindstone along a desired path by a manual operation of an operating member to input the moving path into memory means; and including a playback step in which the processed surface of said workpiece is ground by moving a grindstone along a grinding path which is shifted a predetermined amount from the stored moving path.
CA000533872A 1986-04-05 1987-04-03 Grinding machine and grinding method Expired - Fee Related CA1313308C (en)

Applications Claiming Priority (24)

Application Number Priority Date Filing Date Title
JP61-78596 1986-04-05
JP1986051093U JPS62161963U (en) 1986-04-05 1986-04-05
JP61078595A JPS62236661A (en) 1986-04-05 1986-04-05 Polishing machine
JP61-51093 1986-04-05
JP61-78595 1986-04-05
JP61078596A JPS62236662A (en) 1986-04-05 1986-04-05 Polishing machine
JP61081572A JPS62241649A (en) 1986-04-09 1986-04-09 Polishing machine
JP61-81572 1986-04-09
JP61-81573 1986-04-09
JP61081573A JPS62241650A (en) 1986-04-09 1986-04-09 Polishing method
JP61081575A JP2555319B2 (en) 1986-04-09 1986-04-09 Pressurizing device for grindstone in sander
JP61-81575 1986-04-09
JP61145411A JPS632660A (en) 1986-06-21 1986-06-21 Polising machine
JP61-145410 1986-06-21
JP61145410A JPS632659A (en) 1986-06-21 1986-06-21 Polishing machine
JP61-145411 1986-06-21
JP13055986U JPS6335578U (en) 1986-08-27 1986-08-27
JP61-130559 1986-08-27
JP61233953A JPS6389262A (en) 1986-09-30 1986-09-30 Polishing device
JP61-233952 1986-09-30
JP61-233953 1986-09-30
JP61233952A JP2569295B2 (en) 1986-09-30 1986-09-30 Polishing equipment
JP61307445A JPS63156649A (en) 1986-12-22 1986-12-22 Teaching method for polishing machine
JP61-307445 1986-12-22

Publications (1)

Publication Number Publication Date
CA1313308C true CA1313308C (en) 1993-02-02

Family

ID=27583325

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000533872A Expired - Fee Related CA1313308C (en) 1986-04-05 1987-04-03 Grinding machine and grinding method

Country Status (1)

Country Link
CA (1) CA1313308C (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108544364A (en) * 2018-05-24 2018-09-18 镇江金莱宝光电有限公司 A kind of sapphire stereo omnibearing formula grinding device
CN108890446A (en) * 2018-07-25 2018-11-27 湖州永昆石材有限公司 A kind of stone machining equipment
CN114126792A (en) * 2019-07-24 2022-03-01 西铁城时计株式会社 Machining device, control device used for same, and control method for machining device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108544364A (en) * 2018-05-24 2018-09-18 镇江金莱宝光电有限公司 A kind of sapphire stereo omnibearing formula grinding device
CN108890446A (en) * 2018-07-25 2018-11-27 湖州永昆石材有限公司 A kind of stone machining equipment
CN114126792A (en) * 2019-07-24 2022-03-01 西铁城时计株式会社 Machining device, control device used for same, and control method for machining device

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