US2509070A

US2509070A - Device for producing camshafts and the like

Info

Publication number: US2509070A
Application number: US767095A
Authority: US
Inventors: Musyl Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-05-25
Filing date: 1947-08-07
Publication date: 1950-05-23
Anticipated expiration: 1967-05-23
Also published as: CH269578A

Description

May 23, 1950 MUSYL 2,509,070

DEVICE FOR PRODUCING CAMSHAFTS AND THE LIKE Filed Aug. 7, 1947 6 Sheets-Sheet l IN VEN TOR.

901955 T MUSVL )4? TOFPNEV.

R. MUSYL DEVICE FOR PRODUCING CAMSHAFTS AND THE LIKE May 23, 1950 6 Sheets-Sheet 2 Filed Aug. 7, 1947 INVENTOR.

ROBER T' MUSVL A 7'TORNEK May 23, 1950 us 2,509,070

DEVICE FOR PRODUCING CAMSHAFTS AND THE LIKE 6 Sheets-Sheet 3 Fig. 7

Filed Aug. 7, 1947 IN VEN TOR.

R0551? T MUS VL A TTOPN K May 23, 1950 R. MUSYL 2,509,070

DEVICE FOR PRODUCING CAMSHAFTS AND THE LIKE Filed Aug. 7) 1947 6 Sheets-Sheet 4 Fig.8

IN VEN TOR.

ROBERT MUS VL A 7' TORNEV.

May 23, 1950 R. MUSYL 2,509,070

DEVICE FOR PRODUCING CAMSHAFTS AND THE LIKE Fig.1l]

IN VEN TOR.

ROBE/ T MUSYL A A. D

I ATTORNEK Patented May 23, 1950 DEVICE FOR PRODUCING CAMSHAFTS AND THE LIKE Robert Musyl, Vienna, Austria Application August 7, 1947, Serial No. 767,095 In Austria May 25, 1946 Section 1, Public Law 690, August 8, 1946 Patent expires May 25, 1966 13 Claims.

Conventional processes and devices for producing cams on cam shafts by means of shaving tools, and in particular by grinding, are based on the so-called copying principle whereby the grinding tool is directly controlled by a mastercam machined to the utmost degree of accuracy. However, it is a well-known fact that very substantial differences are inherent to said copying process which unfavorably affect the accuracy of the cams in case of quantity production, the greatest drawback being that with increasing wear of the grinding wheel the cam profiles become more and more distorted. Hence, the grinding wheel can be worn very little and its life is very short. Theoretically the slightest wear is sufficient for causing inaccuracy.

Avoiding excessive tool costs entails defective cams which, e. g. in engines, and in particular in internal combustion engines, causes irregular cut-offs. This explains in many cases the great differences in output and performance of the motors of the same lot.

The object of the invention is the provision of a new process and a device for executing it whereby all cams of a lot are perfectly alike and the tool machining the cam operates at right angle to the curve. This applies to the grinding of the cam a well as to the turning on the lathe. A further object of the invention consists in the provision of a method and means for performing all the working operations from turning to grinding on the same machine without interrupting the continuity between turning and finishing,

In contradistinction to the true copying process the tool is controlled by a combination of control elements which are characterized substantially by two profiles of which one is used for producing the horizontal components of the tool motion and the other producing the vertical component, both however operating in a cinematically congruent manner over concentric radii of the work.

It is further of importance that with the same device geometrically similar cam profiles may be produced within certain practical limits. Since the tool carrier travels along a relative path having approximately the shape of a kidney the lengths of whose axes are at a certain proportion to each other, which may be changed for obtaining geometrically similar profiles.

The tool arrier is arranged on a rocking lever of the type of a pendulum lever the lengthening or shortening of which acts on the increase or reduction of the cam excentricity whereby the change of the cam size influences the entire shape of the cam.

Of course, this rocking lever is rotatable at one end and telescopes for assuring freedom of its movements.

Other special arrangements and details relate to the dependence and adjustment of the distances between the ful-crums of the rocking levers and their sliding guides. Furthermore, provisions are made for assuring dependence of the speeds of the motors for moving the tool support and for rotating the tool. An electric coupling has been provided, by the use of synchronous motors. In the following description all these details are minutely explained.

The drawings show embodiments of the invention by way of examples, Fig. 1 illustrating the inventive principle of the process in the basic position, Fig. 2 in a position in which the work has revolved through a certain angle, Fig, 3 representing the position for machining the vertex of the cam, and Fig. 4 the machining position of a further cam flank or face. Fig. 5 illustrates the relative path of the control and the curve along which the tool frame (or support) is displaced. Figs. 6 and '7 illustrate diagrammatically the principle according to which the control is adapted to the size of the cam to be produced. Fig. 8 is a side elevation, partlyin section of the machine according to the invention, Fig. 9 a plan view of same with the gear box opened, and Fig. 10 a front view of the machine.

Referring to Fig. 1 W is the work contacted by the tool S in point I. Since the point I is situated on the connecting line MO, and also on the concentrical arc l-l, the tool S e. g. a grinding wheel occupies the zero or starting position and the centre SM of the tool s is located on the line n, which is normal to the arc. If the work rotates with the angular velocity 0: around M, the control members or the master-cams N1 .and N2 must rotate with the angular velocity w1=w. The control members N1 and N2 must be designed in such a manner that the centre of the tool SM is always located on the perpendicular to the curve.

Various preferred points of the periphery of the work are designated. by the numerals l-l, the respective perpendiculars to the curve being designated by the letters Mir-n6 whereby the perpendicular n1 is coordinated to point I as well as 1. Furthermore the angles between these perpendiculars to the curve 7L27L6 and the zero line OM are designated by az-as, the corresponding points of the master-cam or the control member N1 by l-'i, and the corresponding centres of the temporary excentnicities between i-Z, and $1 by M1 and M2, and between l-2', and l by 01 and 02.

Points

3, 4 and 5 have been selectedior demonstrating the operating conditions at the moments of their machining. The perpendicular m to the curve at point 3 encloses angle all with the axis :1: which is also the perpendicular to the curve m in the initial position. If the work is turned through angle as into the position according to the Fig. 2 the perpendicular to the curve is moved to horizontal position. The cam N1 moves the link K1 into the position 3 whereas the cam N2 controls the link K2 in such-a manner that the center SM of the tool is lifted by the distance b3, b3 signifying the distance of the perpendicular to the curve m from the connecting lineMO (Fig. 2) which is identical with the perpendicular to the curve 111 in the starting position. Hence the tool center is located on the perpendioular m to the curve portion 3 of cam N1.

Line 113 is identical with the perpendicular m of Fig. 1 turned into the horizontal direction.

If the work turns clockwise through angle :14, the link K1 is moved by the cam N1 to its maximum displacement to the right and the vertex .of the cam at 4 is machined. By the rotation through the angle 124 point l has arrived at the position according to Fig. 3. In this position the perpendicular 114 must have reached the zero position m which is identical with the line MO whilst the cam N2 has moved the link K2 to the vertical zero position.

Further rotation of the work from the position according to Fig. 1 through the angle at to the position in which the perpendicular as to curve .5 assumes position 115', causes the cam N1 to move the link K1 into the position illustrated in Fig. 4 whereas the cam N2 lowers the link K2 through the distance be whereby the center SM of the grinding wheel S is. equally lowered. Link K2 has now reached its lowermost position and returns therefrom to the zero position :c-a: according to Fig. 1. While the concentrical circular are 1-! is machined neither the link K1 nor the link Kz will be moved, the two cams N1 and N2 having a circular arc portion for this purpose. After point I of the work W has reached the initial position shown in Fig. l the movements described above are repeated.

The relative path of the tool is shown in Fig.

5, in which E designates the long axis and A the short one. The positions corresponding to thepoints l-l of the periphery of the work W are designated by I",3", d", 5" and l". The horizontal components h of the movement are produced by the cam N1 and the analogous vertical components 1; by the cam N2.

In practice, there are a great number of geometrically similar cams or profiles. Irrespectively of whether these profiles are derived from so-called master-cams or are produced by a kinematic process it is sufficient to produce in the machine or device but one relative path of the tool. This is explained by the fact that for geometrically similar profiles the relations A:B of the relative path according to Fig. 5 is constant. If therefore a geometrically similar profile is to be produced whereby however the lift of cams N1 and N2 may be more or less high than the original profile, it is possible according to a further development of the invention to adjust the lift of the two cams continually whereby the relation A:B is maintained.

The Figs. 6 and 7 illustrate diagrammatically an embodiment of the invention.

By means of the so-called master-cam N1 the horizontal movement of member K1 is controlled, its stroke being equal to A/2. The oscillating member T is pivoted to member K1 and member T is rotatably supported at the point CS1 in the slide S1. On the oscillating member T a ball bearing G2 is provided which is supported by the slide L1 If slide K1 moves by the distance A/2 the slide I11 moves by the distance A1/2 for a specified relation of the distance 021302. For maintaining the geometrical relations telescopes T1 and T2 are inserted between points G1 and G2, and G2 and CS1. If it is desired to change the strokeA1/2 the slide S1 the movement of which is indicated by the double arrow 20 is displaced .e.-g. by rotation of a self-locking threaded spindle Gspi (indicated by dot dash lines in the drawing) whereby the relation $12022, and consequently the relation A/-2:-A1/2 is altered.

According to the shape-ofthe relative path in Fig. 5 member K1 produces also the vertical movement. If the device is arranged in such'a manner that the proportion IE3Z$4 is equal to 3011.102 (Fig. '7) the slide L1 will :movealong an enlarged or a reducedrelative path. For adapting the invention to a device of this kind, the

oscillating member Tzslides according to Fig. '7 in a guide of member K1 by way of a pendulum ball bearing Pm and in the slide L1 by way of a pedulum ball bearing Pm.

If the centers 0s1 and 052 according to the Figs. 6 and '7 are uniformly'displaced a uniform reduction or increase of the length of the axes A and B will take place. For this purpose it is advisable to connect the threaded spindles Gsm &nd GSP2 by means of toothed wheels.

There is a number of profile kinds mostly of kinematic origins in which the relative path is produced by the rotation of two different-eccentries in such a manner that-from one eccentric the horizontal component is derived and from the other only the vertical component. According to whether a two-cornered, three-cornered, or

n-cornered profile must be produced, therelation A/B will be equal to 1:2, 1:3 or .lzn.

By the 'present'inventionithe relative path according to Fig. 5 may .be derived from only one circular movement. It isxonly necessary to displace the slides S2 and S1 by diiierentdistances. This is accomplished by providing different toothed wheel gears :b'etween-the spindles Gem and Gene. For grinding anin-corneredfpart the ratio of transmission 1': n'iszemployed.

The Figs. 8-10 illustrateby'way oi'example a device or machine embodying the invention.

By way of a toothed wheel gear. Z1, Z2 and Z3 motor MO, drives an exchangeable'cam drum N. By means of the links K1 the cam drum N displaces the slide K in 'horizontaldirection. To

the straight-guided slide K a vertical guide F1 is screwed, on which the link K2 is free to glide up and down. If link K2 is movedaccording to'the shape or cam N1 the pendulum ball bearing PK! will participate in the movement. As the guide F1 moves horizontally, the link K2 glides overthe ball bearing PKlwithout-any effect (Fig. 8).. The vertical component of the relative path is transmittedby way of the pendulum ball bearing ill-K2 and the oscillating member Tazrotatable about 082 to the swinging body and :the :tool carrierSw. The horizontal movement of the body K is transmitted by way of the oscillating member T rotatable about 081 and by way of the ball bearing G2 to the straight-guided slide L1 and the guide F2. Consequently the swinging body Sw will travel along the reduced or increased resulting relative path.

For altering the relative path the threaded spindles Gs1 1 and GsP2 are revolved. This is done by hand by a hand wheel (Fig. fitted with a scale disc SK by way of exchangeable spur gear wheels R1 and R2 acting on the threaded spindles GSPl and Gen. Thereby the slides S1 and S2 are displaced. This continuous adjustment of the strokes provides for utmost precision. Swing body SW glides between two lateral walls W1 and W2, and rests on ball-bearings Kg, which are guided by coupling rods St. The pressure on the guides is obtained by a spring Zrand the reaction of the tool pressure.

In the embodiment of the invention in a universal cam turning and grinding machine the entire swinging body Sw may be rotated about a pin As whereby either the grinding wheel S or the tool holder D51. may be applied. The swinging body may be clamped in any position within its range of movement.

The grinding wheel S is driven through the belt RT by a motor M02 located on the swinging body Sw. As the swinging body Sw must be moved at a certain ratio to the speed of the work the two motors M01 and M02 (Fig. 10) must be coupled mechanically or electrically. In the present case two synchronous motors have been provided.

In other respects the design of the machine is the same as that of a conventional grinding machine having a head stock II, a bed l2, and puppet I3.

I claim:

1. A machine for machining cams including a work holder, a movable tool holder, two rotating master cams, means interconnecting said cams and said tools holder for moving it horizontally under the influence of one cam and vertically under the influence of the other cam, and means connected with said first means for varying the magnitude of the horizontal and vertical movements of the tool holder.

2. A machine for machining cams including a work holder, a movable tool holder, two rotating master cams, means interconnecting said cams and said tool holder for moving its horizontally under the influence of one cam and vertically under the influence of the other cam, and means connected with said first means for varying individually the magnitude of the horizontal and vertical movements of the tool holder.

3. A machine for machining cams including a work holder, a movable tool holder, two rotating master cams, means interconnecting said cams and said tool holder for moving it horizontally under the influence of one cam and vertically under the influence of the other cam, and means connected with said first means for varying simultaneously the magnitude of the horizontal and vertical movements of the tool holder.

4. A machine for machining cams including a work holder, a movable tool holder, two rotating master cams, means interconnecting said cams and said tool holder for moving it horizontally under the influence of one cam and vertically under the influence of the other cam, and means connected with said first means for varying simultaneously the magnitude of the horizontal and vertical movements of the tool holder, the

6 variation of 'the horizontal movement' being different in magnitude from that of the vertical movement.

5. A machine for machining cams comprising a rotatable work holder, stationary bearing means for said holder, a tool holder, a movable support rotatably supporting said tool holder, a stationary base member vertically slidably connected with said support, a horizontally swingable lever member, a vertically swingable lever member, pivot means connected with said base member and individually swingably supporting said lever members, connecting means movably connected with said lever members and with said support for transferring the motions of said lever members to said support, a cam shaft rotatably supported by said base member, two master cams fixed on said shaft, a slide member horizontally slidably connected with said base member and movably connected with said first lever member and having a cam follower portion engaging one of said master earns, a second slide member vertically slidably connected with said first slide member and movably connected with said second lever member and having a cam follower portion engaged by the other master cam, and drive means connected with said work holder, with said tool holder, and with said cam shaft for driving these parts in synchronism.

6. A machine as defined in claim 5, having individual electric synchronous motors for rotating said work holder, said tool holder, and said cam shaft.

7. A machine as defined in claim 5, comprising individual support means for said pivot means movably connected with said base member and being individually displaceable in the direction of the longitudinal axes of said lever members for adjusting the leverage thereof.

8. A machine as defined in claim 5, comprising individual support means for said pivot means movably connected with said base memher and being individually displaceable in the direction of the longitudinal axes of said lever members for adjusting the leverage thereof, and a common drive means for said support means for moving same simultaneously.

9. A machine as defined in claim 5, said lever members comprising telescoping portions for affording free movement of the connections of said lever members with said support and with said slide members.

10. A machine for machining cams comprising a rotatable work holder, stationary bearing means for said holder, a tool holder, a movable support rotatably supporting said tool holder, a stationary base member vertically slidably connected with said support, a horizontally swingable lever member, a vertically swingable lever member, connecting means movably connected with said lever members and with said support for transferring the motions of said lever members to said support, a cam shaft rotatably supported by said base member, two master cams fixed on said shaft, a slide member horizontally slidably connected with said base member and movably connected with said first lever member and having a cam follower portion engaging one of said master cams, a second slide member vertically slidably connected with said first slide member and movably connected with said second lever member and having a cam follower portion engaged by the other master cam, drive means connected with said work holder, with said tool holder, and with said cam shaft for driving these QQOQQTO parts in synchronism, individual pivot means in.- dividually-swingab'ly supporting said lever members, guide means connected with said base memher and horizontally, individually slidably supporting said pivot means for displacement. thereof: in. the direction of the longitudinal axesof said lever members, and self-locking displacing means connected with said pivot means for dis,- placing said pivot means for changing the leverage of said levers.

ll. A machine for machining cams. comprising a rotatable work holder, stationary bear: ing means for said holder, a tool holder, a movable support rotatably supporting said tool hold:- er, a stationary base member vertically slidably connected with said support, a horizontally swingable lever member, a vertically swingable lever member, conn cting means. movably connected with said lever members and with said support for transferring the motions of said lever members to said sup-port, a cam shaft rotatably supported by said base member, twolmaster cams fixed on said shaft, a slide member horizontally slidably connected with said base member and movably connected with said first lever member and having a cam follower portion engaging one of said master cams, a second slide member vertically slidably connected with said first slide member and movably connected with said second lever member and having a cam follower portion engaged by the other master cam, drive means connected with said work holder, with said tool holder, and with said cam shaft for driving these parts in synchronism, individual pivot means individually swingably supporting said lever members, bearing means for said pivot means, stationary guide means horizontally, individually slidably supporting said bearing means for displacement thereof in the direction of the longitudinal axes of said lever members, and individually threaded spindles screwed individually into said bearing means for displacing same upon rotation of the spindles.

12. A machine for machining cams comprising a rotatable work holder, stationary bearing means for said holder, a tool holder, a movable support rotatably supporting said tool holder, a stationary base member vertically slidably connected with said support, a horizontally swingable lever member, a vertically swingable lever member, connecting means,- movably Connected with said; lever members and with said. support for transferring the motions of said: lever members to-v said". support, a cam shaft rotatably sup,- ported by said base member, two master cams fixed on said shaft, a slide member horizontally slidably connected with said base member and movably connected with said first lever member and having a. cam follower portion engaging one of said master cams, a second slide member vertically slidably connected with said. first slide member and movably connected with. said second lever member and having a cam follower portion engaged by the other master cam, drive means connected with said work holder, with said tool holder, and with said cam shaft for driving these parts in synchronism, individual pivot means individually swingably supporting saidlever members, bearing means for said pivot means, stationary guide means horizontally, individually slidably supporting said bearing means for displacement thereof in the direction of the longitudinal axes of said lever members, individually threaded spindles screwed individually into said bearing means for displacing same upon rotation of the spindles, a spur gear wheel connected with each spindle, the teethof one wheel registering with the teeth of the other wheel, and a common drive for said wheels.

13. A machine as set forth in claim 12, said gear wheels having different diameters and tooth numbers for changing the leverage of said lever members in a different degree.

ROBERT MUSYL.

REFERENQES CITED,

The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,192,888 Blazek et al. Mar, 12, 1940 2,267,250 Mossdorf Dec. 23, 1941 2,415,062 Green Jan. 28, 1947 FOREIGN PATENTS Number Country Date 417,612 Great Britain Oct. 9, 1934