US3903651A

US3903651A - Grinding machine

Info

Publication number: US3903651A
Application number: US516661A
Authority: US
Inventors: Shigekazu Suzuki; Masaharu Shibata; Hirotake Kishi
Original assignee: NHK Spring Co Ltd
Current assignee: NHK Spring Co Ltd
Priority date: 1973-10-25
Filing date: 1974-10-21
Publication date: 1975-09-09
Anticipated expiration: 1992-09-09
Also published as: DE2450614A1

Abstract

A grinding machine has a grinding wheel mounted on one side of a straight passageway and adapted to grind the end of workpieces, such as coil springs, continuously fed on a carrier. The grinding machine further has a position setting mechanism for setting the position of the grinding wheel relative to the workpiece and a dressing mechanism for dressing the grinding surface of the grinding wheel. A speed reducer equipped reversible motor is employed for moving a position setting element of the position setting mechanism, or a dressing element of the dressing mechanism, in a direction substantially perpendicular to the grinding surface of the grinding wheel, while an air cylinder is employed for moving the position setting element, or the dressing element, in a direction parallel to the grinding surface of the grinding wheel.

Description

"United States Patent UN I Appl. No.: 516.66l

Foreign Application Priority pm Oct. 25. 1973 Japan 48-l23866IU] Oct. 25, i973 Japan 48-l23867lU] References Cited UNITED STATES PATENTS 6/1930 Rodcmcycr.... 5lll l2 4/1957 Clcrcq Sl/l l2 4/l959 Price SI/l l2 ,Suzuki et al. 5] Sept. 9, 1975 l l GRlNmNG MACHINE $640,024 2/1972 Stahn 5115 D x 3.739.528 6/l973 Robillard 5l/l65.87 X

[75] inventors: Shigeluizu Suzuki, Yokohama; 4 d 51 I I0 Masha! shibam, m; 3,84L027 Ill/I97 Ban 0 l I Hirotake Kmhi, lwute, all of Japan Primary Examiner Dna|d Q Kelly ssign: NHK Spring Co., Ltd., Yokohama, Attorney, Agent. or Firm-Flynn & Frishauf Japan 221 mu: on. 21. m4

A grinding machine has u grinding wheel mounted on one side of a straight passageway and adapted to grind the end of workpieces, such as coil springs, continuously fed on a carrier. The grinding machine further has a position setting mechanism for setting the position of the grinding wheel! relative to the workpiece and a dressing mechanism for dressing the grinding surface of the grinding wheel. A speed reducer equipped reversible motor is employed for moving a position setting element of the position setting mechanism, or a dressing element of the dressing mechanism, in a direction substantially perpendicular to the grinding surface of the grinding wheel, while an air cylinder is employed for moving the position settin element, or the dressing element. in a direction parallel to the grinding surface of the grinding wheel.

5 Claims, 3 Drawing Figures PATENTEUSEP- 9191s S'ziEEI 1 BF 3 FIG.

Pmmmw 9191s sum 2 BF 1993-551 FIG. 2

PATENTEDSEP' 9191s sum 3 nr 3 :FIG. 3

l GRINDING MACHINE BACKGROUN D OF THE INVENTION This invention relates to a grinding machine for grinding the end of workpieces such as coil springs, and

' in particular to a grinding machine having a grinding chanlsm for periodically dressing the grinding sur-' )ace of the grinding wheel so as to prevent clogging of he grinding surface of the grinding wheel, while accurately correcting a grinding-surface in an attempt to ob tain a flat grinding surface. 7 In such a grinding machine, the grinding surface of a grinding wheel is gradually worn. away, resulting in varying the grinding position of the grinding wheel relative to a workpiece. It is therefore necessary to corrcctly position the grinding surface of the grinding wheel relative to the workpiece each time a predetermined amount of grinding operation is effected. It is also necessary to prevent clogging of the grinding surface of the grinding wheel. while accurately correcting the grinding surface of the grinding wheel in an attempt to obtain a flat grinding surface.

The dressing andposition setting of the grinding wheel has heretofore been manually cffected in an arbitrary way. It is. therefore. impossible to correctly position the grinding wheel relative to the workpiece, as

well as accurately correct the grinding surface of the grinding wheel in an attempt to obtain a flat grinding surface. As a-rcsult, an'operation efficiency is prominently impaired.

SUMMARY OF THE INVENTIQN An object of this invention is to provide a grinding machine capable of accurately positioninga grindingwheel relative to a workpiece and capable of-rapidly and positively 'correctingthe grinding surface .of the grinding'wheel in an' attempt to obtai'n'a'flat grinding surfaceas well as preventing clogging of the grinding surfaceof the grinding wheel.

Anotherobject of this invention is to provide a grinding machine capable of being automatically and periodically setting the position of a grinding wheel relative to a workpiece; as well as capable of being automatically and periodicallydressing the grindingsurface of the grinding wheel. 2 3 v 1 One feature of this invention resides in that a dressing element to be'contacted direct to the grinding surface tially perpendicular to the grinding surface of the grind ing wheel as-well as in a direction substantially parallel to the grinding surface of the grinding wheel, The perpendicular movement of the drcssing clemcnt is efmechanism including a reversible mo-- and a reciprocable plunger member driven by the air cylinder. A second feature of this inventionresides in that a position setting element for setting theposition of the grinding wheel relative to the workpiece is movable in a direction substantially perpendicular to the grinding surface of the grinding wheel as well as in a direction substantially parallel to the grinding surface of the grinding wheel. The perpendicular movement of the position setting element. is effected by a first mechanism similar in arrangement to the abovementioned first mechanism, while the parallel movement of the position setting element is effected by a second mechanism similar in arrangement to the above-mentioned second mechanism.

With the grinding machine according to this invention. the position setting and dressing of the grinding wheel can be respectively effected by the substantially similar and simple mechanism. This makes it possible to simplify the construction of the grinding wheel, leading to a low cost. The position setting and dressing of the grinding wheel can be: automatically effected in a periodic way.

In this case. not only can the reduction of labor be attained. but also an increased operational accuracy can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. -l, ,a' grinding machine according to this invention has a dressing mechanism 10 and a position setting mechanism l1 which are arranged in asso-' .shown inFlCiS. 2 and 3, which is placed in a direction transverse to the longitudinal direction of the passageway 14. The grinding wheel 12 is rotated by a shaft 15 and is-movable in the axial direction of the shaft 15 by moving mechanismnot shown. The coil springs 13 are supported bysubstantially V-shaped receiving members 18. respectively, which are successively arranged I atapredeterminedinterval on abase plate 17 driven, of the grinding wheel -is movable in a direction su'bstan- I in adirection indicated by an arrow A in FIG.- I,' by an endlessbelt 16. As will be evident from FIGS. 2 and 3, eaeh'receiving member 18 consists of three pieces 18a, 18b and 18c arranged in a direction transverse to the longitudinal direction of the passageway 14. The pieces 18a and 180 support the end portions of the spring l3. while the central piece 18b supports the eentralportinn of the coil spring l3. Each coil spring 13 is supported.

' in the. direction transverse to the longitudinal direction of the passageway 14, by the three pieces on the base plate 17 and one end of the coil spring faces the grinding wheel 12. On the side surface of the piece I811 of each receiving member 18 a clamping member l9 ti es the contaet elemcnt is contacted, with theicoil stands upright and is adapted to'clamp the coil spring U in cua'ction with the V-shape'd receiving member 18 so that. during the grinding of the end lJa of the coil spring 13, the coil spring i3 neither displaced he: dislocated from the receiving member l8.'l'he cndlessc'hain 16 is secured to the'undersurface of the .piate I? through connecting members 20 which are disposed at a predeterminedinterval on th e'undersur i'ace of the baseplatel7. I

At a suitable position of the passageway 14a contact element 21 is provided. .The contact element 21 pated be contacted with the coil spring" passing thereth ugh. The contactelement Zl is eonnec'ted to the counting mechanism count the number of spring 13. Thus. the number of the coil springs passing through the contact element, 21 can be counted Whena predetermined nu rnberfof,

sensed by the contact element 21, a dressing operation starting signalis delivered from the eountingl inecha-f. nism and whenthe other predetermined number eoil springs 13 are sensed the contact' elerrreht Ilia l posii tion setting operation starting"signaifisdeiivered from the counting ,rr'te chanism .21,

The dressing mechanism) more in detail; r Operated. by dressing {operation starting signal andthe position setting mechanismll as will be described latermore indetail V operated position setting operation'starting signal. 5 1-,. w

With the dressingmechanism l hownf ri 2a speedreducerfequippedreversible motor is secured: to a

maehine framejl

22,15 cylindrical ,casing,24'-is a threaded is arrangedtobe driven byithe' 'motor 23. The threaded rod 1Z5is'coupled at one endto a].

trical counting mechanism. not shown. s

- drssiri g'i'blerri'e'nt- 3 8'ieffects a good 'uniform dressing 4' i the um 36 is swung through a predetermined angle from an originatposititm shown.

,When a dressing operation starting signal is delivered from the cbu ritin'g'rnechanism connected to the contact 5 element 2i; th'e motorjli and airlcylinder 32 are oper- -The operation of the motor 23 causes the threaded rod 25 to be rotated in one direction to permit the sliding block 26.1'6 be ailvariced. This'causes the block'mernber 30 be moved in a direction substanio tinny perpendicular to the grinding surface of the grii'idiii 'wheel'tz'to'pe nir the'dres'sing element 28 to' be abutted a'gainstflhd grinding surface 120 of the grinding 'wheell Z. when, after abutment, the block member 30 is further-slightly moved. the arm 36 is swung clockwise z't'g'iiin'st'theiblasin'g force of the spring 39 to'catis'e the limit 40th closed. As a result; th'e'motor 23'is'stoppedand the'ritovement of thebloclt mcmber stopped. An electrical connection he I tween theswitch 4'0 and the motor 23 is 'oiiiinea'ih his lnE'this, state, the airicjlinder n' causes the plunger mein ber 33 to' reciproably"'mov'ed while being maintained irifa sta'td parallelito' the grinding surfac'e t2airuig inaing 12; By this reciprocating mevehi ii er'i 'e iieii ei lhernber 33 the'dressing'elef'eCipi'oCablyTmovedQivhile being urged' merit V "against the grinding surface lfla of tl-iegrinding wheel 12: substantially i'adiall'y of the grinding wheel '12 and *fi ra' direction substant ially'parallel to t grinding sure fac'e- 12d 'ofth 'grindi'n'g wheel 12. During this period.

the grinding" wheel llicontin ues to'berota ted and the' nwlieel nz'preveniing cloggin'i'g olthe grinding surface 12a of the'grindingwheel l2 while accurately correctt 'ing the grindin'gfsurface-otthe gtin ng'wheel in an atshah of ""9 m? vhF" F tempt to obtain-a flat grinding surface. the other end screwed Into anmternal thread 21 :Ylhlghl 40 zy zm'ai h p fibh a a for a piedcteb is formed inr-a sliding block of:

the shank b mjthm ed we wt t bwt ti wn a: by bearings 18 which; are fitted into the sliding bioett'zs is slidably moved outwardly of t e and is slidably retracted into .the' casing"24 by rotating the threaded rod 25 inithe' other direction.-

way. the sliding block s lidably 'guidedalong the'jnner surface b theeesi i -za A A' stub shaft? fixed tq thefputer endxo member a r: air icylinder,dziisifl'ftotttttetlitltrottgiiia .i

mally in abutment with an abutment'iportion fid ip'qf formed on the box.34. AJimit switch40 isdisposii within the chamber 35'and'adapt ed to be closed when face tza rthe grinding wheel. s ii'i neiiee'un there-' r withl'tiieaii: gr nders; s-ai-ive' ijt o''e'r ie'e the dressing n 3 l ts" 'iP Q'J' wds m n p m e .50 block 26 is secured to a block'member'30. To he bloelt fa ii fi gis w; vi.- i. w

and ai ib'iiije't'ianyjbperiited eaeh'ti iie th dressing e 't' settingmechanism ll,

g ei-feiii i edhiote; "41' is mounted. A

trdtti't'edubyfthe rod connected at l ii-t l'm 4 thr shf fi v ns n i a sliding block The eeiiiiei' the threaded is" rotatably by bearings 46', 46 which ttrfe' fitied into thegeasingfii The sliding block 44 is slidably' 'b'uttva rdl'yfof the rotating the A threaded rod 43' ihgeiieaiieeueii and slidably retracted in'tothe casin'g the threaded rod 43 in'the othe r, 'cjlireetio'ni-ln this way, the sliding block 44 is slid- 'ublf'guided along the inn'er surface of cylindrical casing wa yft he dressing 'cler'n'efnt; 38xis held, under the Ptctioh of the spring 39, itiii state in which it is eltis tically urg'e'd" it towardthe grinding sufl'ace'liZa of grinding wheel 12.

I l to tiei traet 'd; A faj'res i c. thebloek'member so is" t i i. w moi isdiina' revetse" direction to eause-the'dressing 2 w Malina thsthmdcd'rodis' n "s=4!".-'' n member-sate be mated weyjrrei ithe grinding "mi-- is mounted on a 'maehine frame 22 '7 and frame '22. Within the cyii'iw' lSe ther'er'id seie eq inte'rn'al thread, 45 fonned in i 42. A stub shah 47 fixed to the outer end of the sliding block 44 is secured to a block member 48 an air cylintlcr 50 is mounted through a bracket 49.

A plunger member 51 of the air cylinder 50 passes through the block member 48 and extends below the block member 48 in a state parallel to the grinding surface 12a of the grinding wheel 12.

The structure of the above-mentioned position setting mechanism 11 is substantially similar to that of the dressing mechanism of H6. 2.

In a position somewhat remote from the lower end of the plunger member 51 an enlarged portion 5 la is intogr lly formed. A roller-like position setting element 52 is otatably mounted on the lower end portion of the p nger element 51. A lever 53 is mounted by a pivot '4 on the side surface of the enlarged portion Slu of the plunger member 51 and has upper and lower arms 53b and 53a. The lower arm 53a extends up to the posltio'nsetting element 52.'A compression spring 55 is dis posed between the upper arm 53b and-the enlarged. portion 51a. The lever 53 is constantly urgedcounterclockwise. under the-action of the compression spring 55. as shown in HQ. 3. The lever 53 is normally held against the urging force of the spring 55 inlan original position in which it is eagage dwith' a stop 56 fixedto the enlarged portion 510 of the plunger member 5 1. ln

this original position the end of the lower arm 53a of the lever 53 forwardly extends vsomewhat beyond the position setting element 52. A limit switch 57 isalso provided between the upper arm 53b of the lever 53 and the enlarged portion 51a of the plunger-member 51. The limit switch 57 is adapted'to be closed when the lever 53 is swung through a predetermined angle from the original position.

When a position setting starting signal is delivered from the counting mechanism connected to the contact element 2!, the motor 41 and aircylinder 50 are operated. The operation of the motor4l 'causes threaded rod 43 to be rotated in one direction topennit the slid-' i ing block 44 to be advanced a predetermined distance.

Simultaneously therewith.,thc block member 48 is i moved in a direction substantially perpendicular to the grinding surface 12a of the grinding wheell2 and the position setting element 52'is set in a predetermined position substantially perpendicular to the grinding sur face 120 of the grinding wheel 12.

words. the grinding wheel 12 is set in a correct grinding position. An electrical connection between the limit switch 57 and the moving mechanism is omitted.

When the position setting of the grinding wheel l2 is complete. the air cylinder is again operated to cause the plunger member 51 to be lifted up. Simultaneously therewith. the motor 41 is reverse rotated. causing the threaded rod 43 to be rotated in the other direction to permit the sliding block 44 to be retracted. ln consequence. the block member is returned to an original position and the position setting element 52 is moved away from the grinding surface 120 of the grinding wheel 12 and returned to the original position.

The above-mentioned position setting mechanism It is operated after the dressing mechanism 10 has been operated so as to prevent clogging of the grinding surface 120 of the grinding wheel 12. while accurately correcting the grinding surface of the grinding wheel. Even when the dressing mechanism 10 is not operated. the position setting mechanism I1 is usually operated, for

. example, prior to a grinding operation. The time intervals of both the mechanism 10 and it can be suitably determined dependent upon the size and material of a workpiece to be ground. The position setting mechanism 11 and dressing mechanism l0may have substantially the same structure as mentioned above. Since the speed reducer equipped reversible motors 23 and 41 are used as driving means for moving the dressing element 38 and the position setting element 52, respectively in the direction substantially perpendicular to the grinding surface 120 of the grinding wheel I2. 21 very acclirate movement can be provided. With the abovementionedcmbodiment the air cylinders 32 andSO are employed as driving means for moving the

elements

38 and 52, respectively. in the direction substantially parallel to the grinding surface 120 of the grinding wheel 12. Since in this case no accuracy is required. the air cylinders 32, are employed as such.

The motors 23 and 41 and

air cylinders

32 and 50 are automatically operated by applying an electrical or mechanical signal thereto. It is therefore possible to easily incorporate the mechanisms 10 and 11 into an automatic control system. As a result. not only can reduc- The air cylinder so is supplied with ahttiifmih'aii air supply source. not shown, to cause the plunger member 5! to be driven to permit the position setting element 52 to be lowered in a manner.substantiallyparallel to 'tion of labor be attained but also a more accurate,

rapid operation can be effected.

What we claim is: l. A grinding machine comprising a machine frame,

' carrier means for moving workpieces such as coil the grinding surface 12a of the'grinding wheel. IZL 'As a result, the position setting element.SZisset'inapredetermined position substantially parallelf'to the 'grindff ing surface 120 of the grinding wheel 12;:

when t e position'setting'element 52 has hee' s set,

the movingmechanism. not showm is' operated to c'a use l the grinding wheel 12 to be moved toward the position setting element 52 to pcrmit' the grinding surface 12a.

of the, grinding wheel 12 m be abutt'ed agairist the ment 52. Before this abutmer gthe arm-5349f thelever 53 is abutt'ed against the grinding surfacefjhtiof the grinding wheel 12 to cause the lever 53 to be swung. Si

multaneously. with the abutment of the element 52 against the grinding surface l2'aof the g rindin'gwheel 12. the limit switch 57 is closed to cause thei rnoving mechanism to he stopped. As a rcsult. the. grinding wheel 12 is stopped in the abutted-" positiomln other springs. while holding them in a direction transverse to the longitudinal direction of a passageway, driving means for driving the carrier means,- and a grinding wheel rotatably mounted on one sideof the passageway and having agrinding surface substantially perpendicular to an axis of-the workpiece, said grinding wheel being movable in the direction transverse to the longitudinal'direction of the passageway so as to vary a grindir gde pth, said grinding machine further including a reversible -'rn otor mounted" on the machine. frame. a

cylindrical casing..a threaded rod disposed within the cylindrical casing and rotatably driven by the motor. a sliding bloclthaving an internal thread into which the threaded rod is screwed. said sliding block being slidably advanced and retracted by the rotation of the threaded rod. a block member secured to the sliding block and movable in a direction substantially perpcn dicular to the grinding surface of the grinding wheel as t arcsult of the sliding movement of the sliding block. an

air cylinder supported by the block member. a plunger member reciprocably movable by the air cylinder in a direction substantially parallelto the' grinding surface of the grinding wheel. and a'dressing element coupled to one end of the plunger member and adapted to be 5 contacted with the grinding surface'of the grinding wheel. in which the dressing element'is moved. by 'the reversible motor, into abutment with the grinding'sur} face of the grinding wheel and is reciprocably movable.-

by the air cylinder. on the grinding rface oi grinding wheel substantially radially thereof. t

dressing element is elastically urged under the uc-' tin of a spring against the grinding surface 01 the nding wheel.

osition 1h=fs "8 surme'bf t g 'it i g-.v'1heel relative totheworkpicee; i a r ond reversible motor fi xedjto the machine frame. a second cylindrical casing, a second threaded rod disposed within the second cylindrical casingandfrotatablydriven by the second motor. a second sliding slidabiy movable along the inner surface. of the second cylindrieal casing as a result of the rotationpt' the second thre'aded rod. a second block membersecuredto' they 9 grinding machine according to claim I, in which 3. A grinding machine according to clai rnl, further including a position setting meehanism for setting the second sliding block and movable in a direction suhstantially vertical to the grinding surface of the grinding wheel as a result of the sliding movement of the second sliding block. :i'second air cylinder supported on the second block" member. a second plunger member driven by the second air cylinder in a direction substantially parallel to the grinding surface of the grinding wheel. and a positioii setting element connected to one end of the seco'nd plunger and movable into abutment with the grinding surface of the grinding wheel. in which the position of the grinding wheel relative to the workpiece is set by moving said position setting element by these'cond reversible motor in a predetermined position substantially perpendicular to the grinding surface oi the grinding wheel. moving said position serting elernent'by the second, air cylinder into a predeterrnined position substantiallyparallel to th'e grinding surface-bf the=grindii1g wheel and moving the grinding I said position setting mechanisrn further includes .a lever pivoted in a'neighborhood ofpnc end'of the second plunger member and having first'andsecond arms. said first arm 'es tendingin a'neighhorhood of the position -25 setting clement-and being adapted to be abetted against v a the grinding wheel before the'grinding wheel is abutted a'g'ainsttheposition setting element;

-. i one a e e' V:

'intb'abutment position setting element. -zo 5..A grinding machine according to claim'4, in which 1

Claims

1. A grinding machine comprising a machine frame, carrier means for moving workpieces such as coil springs, while holding them in a direction transverse to the longitudinal direction of a passageway, driving means for driving the carrier means, and a grinding wheel rotatably mounted on one side of the passageway and having a grinding surface substantially perpendicular to an axis of the workpiece, said grinding wheel being movable in the direction transverse to the longitudinal direction of the passageway so as to vary a grinding depth, said grinding machine further including a reversible motor mounted on the machine frame, a cylindrical casing, a threaded rod disposed within the cylindrical casing and rotatably driven by the motor, a sliding block having an internal thread into which the threaded rod is screwed, said sliding block being slidably advanced and retracted by the rotation of the threaded rod, a block member secured to the sliding block and movable in a direction substantially perpendicular to the grinding surface of the grinding wheel as a result of the sliding movement of the sliding block, an air cylinder supported by the block member, a plunger member reciprocably movable by the air cylinder in a direction substantially parallel to the grinding surface of the grinding wheel, and a dressing element coupled to one end of the plunger member and adapted to be contacted with the grinding surface of the grinding wheel, in which the dressing element is moved, by the reversible motor, into abutment with the grinding surface of the grinding wheel and is reciprocably movable, by the air cylinder, on the grinding surface of the grinding wheel substantially radially thereof.

2. A grinding machine according to claim 1, in which said dressing element is elastically urged under the action of a spring against the grinding surface of the grinding wheel.

3. A grinding machine according to claim 1, further including a position setting mechanism for setting the position of the grinding surface of the grinding wheel relative to the workpiece.

4. A grinding machine according to claim 3, in which said position setting mechanism further includes a second reversible motor fixed to the machine frame, a second cylindrical casing, a second threaded rod disposed within the second cylindrical casing and rotatably driven by the second motor, a second sliding block slidably movable along the inner surface of the second cylindrical casing as a result of the rotation of the second threaded rod, a second block member secured to the second sliding block and movable in a direction substantially vertical to the grinding surface of the grinding wheel as a result of the sliding movement of the second sliding block, a second air cylinder supported on the second block member, a second plunger member driven by the second air cylinder in a direction substantially parallel to the grinding surface of the grinding wheel, and a position setting element connected to one end of the second plunger and movable into abutment with the grinding surface of the grinding wheel, in which the position of the grinding wheel relative to the workpiece is set by moving said position setting element by the second reversible motor in a predetermined position substantially perpendicular to the grinding surface of the grinding wheel, moving said position setting element by the second air cylinder into a predetermined position substantially parallel to the grinding surface of the grinding wheel and moving the grinding wheel into abutment with said position setting element.

5. A grinding machine according to claim 4, in which said position setting mechanism further includes a lever pivoted in a neighborhood of one end of the second plunger member and having first and second arms, said first arm extending in a neighborhood of the position setting element and being adapted to be abutted against the grinding wheel before the grinding wheel is abutted against the position setting element.