JPS609651A - Cam shaft grinding machine - Google Patents

Abstract

PURPOSE:To make a wide variety of cam shafts grindable in an easy manner, by setting up a rod driving device in the rear end part of a spindle after coupling a rod, which connects a master cam sleeve directly to an index driving device, in an axial direction with some play. CONSTITUTION:A lot-in-a-set of master cams 11 are made to travel on a spindle 4 and supported on a movable sleeve 24, while an index clamping device 25 between a sleeve 24 and the spindle 4 being loosely driven by a rod 34 is installed in one end of the sleeve 24 and likewise an index driving member 40 is installed in the other end. A master cam assembly 30, which makes turning motion so as to be selectively stopped by a braking member 60, and a turning member 39 are rotatably installed on the top of a shaft sleeve 41 via a coil spring 45, while an index driving member 26 is installed in its end part and further a stopper pin 44 limiting the rotation of the shaft sleeve 41 and the turning member 39 to a cam's phase angle and notch groove 39 are installed in the said end part, then a rod driving device 55 is set up in the rear end of the spindle 4. Thus, a lot-in-a- set of cam shafts can be machined with minimum master cams without replacement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cam grinding machine for copying and grinding a cam portion of a camshaft of a multi-cylinder internal combustion engine using a master cam, in particular,
This invention relates to a cam grinder for grinding camshafts with small rods.

FIG. 1 is a front view of a cradle portion that supports a workpiece in a cam grinder. On a rocking table 3 supported by a rocking shaft 2 supported at both ends by a grinding machine table, there is a headstock part A1 on the left side and a workpiece mounting part B on the right side. A work drive tool B, which is equipped with an IIA moving ring 3 that is adjustable in the rotational direction, is fixed to the end of the main shaft rotatably supported by a rocking table 3 in the headstock section A, and the workpiece W is inserted through the drive tool 6. The center 7 (!) is fixed at both ends by the center valve which can be adjusted and fixed in the direction of the main shaft axis on the rocking table 3 so that it can go in and out. Engages with the keyway at the end.

A master cam 77 group is fixed to the main shaft. In the currently used cam grinding machine, the master cam 77 group includes the total number of master cams for each type of workpiece W, and is arranged in parallel on the main spindle shaft.

The rotation of the main shaft is transmitted from the pulley 0, which is fixed at the shaft end of the motor 10, to the step pulley Is a, which is rotatably supported on the same axis as the swing shaft, 2, via the belt. / s b Pulley fixed to the end of the main shaft /6
Rotation is transmitted to and rotated by belt/7.

A rotatable follower roller 2 is arranged on the same side as the cylindrical grinding wheel 3 provided on the grinding head of the grinding machine.

In Fig. 7, grinding wheel /3 and follower o-ra/, 2
are above the rocking table 3, but these are for illustration purposes; the grinding wheel/3 and follower roller/2 are on the side of the rocking table 3, and the rocking table 3 is in the middle of grinding. is one in which one of the master cams l/ is always energized so as to be in pressure contact with the follower roller 7.2.

When the motor io is energized, the pulley /6 is turned, and the main shaft (g) is rotated. The follower rollers 2 roll on the master cam in contact with the oscillator 3, and the oscillating table 3 oscillates about the oscillating axis, and the rotating grinding wheel 13 rotates the workpiece W into a predetermined position. Form the cam profile.

In this type of conventional workpiece support device for a cam grinder, master cams are arranged in parallel in the axial direction in order to coaxially support the workpiece and rotate the master cam. The number of master cams required is the same as the number of cams in the camshaft to be machined.

However, recently there has been an increasing demand for machining many types of camshafts with the same machine, and the number of types of master cams that are incorporated into the same main shaft of a workpiece support device has also increased. However, in order to process many types of camshafts with the same machine, the number of master cams required to process one type of camshaft must be reduced, and the number of types of master cams that are incorporated into the same main shaft of the workpiece support device must be increased. is impossible.

An object of the present invention is to provide a cam grinder that can process many types of camshafts using a minimum number of master cams without having to replace the master cam.

The present invention includes one member of an indexing fixture for rotationally driving the cradle of a cam grinding machine and a main shaft equipped with a master cam, and allows a sleeve supporting the master cam to be slid in the axial direction on the main shaft. The sleeve is arranged to rotate in the direction of rotation with resistance, and one end of the sleeve is provided with the other member of the index fixture that engages with the index 2 fixture of the main shaft, and the other end of the sleeve is The master cam assembly includes an indexing driven tool that engages with an indexing drive device provided on the main shaft, and connects the indexing drive device to a rond movable in the direction of the center axis of the main shaft, and also connects the master cam sleeve and the rond. are connected with some play in the axial direction, and a Rondo drive device is arranged at the rear end of the main shaft, and a brake device of a master cam assembly is arranged.

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the axial direction refers to the axial direction of the main shaft, although it may not be specified otherwise.

FIG. 2 is a longitudinal sectional view including the main shaft of the headstock portion A of the cam grinder.

The main shaft G is fitted into bearings 2/ and 22 provided in bearing stands /g and /9 fixed to the rocking table 3, respectively, and is supported so as not to move in the axial direction. An index plate 23 is fixed to the main shaft as one member of the circumference indexing fixture of the master cam/l. The index plate 23 has notched grooves a3-/... according to the number of cylinders, as shown in FIG. 3I, which is a developed view of the outer periphery viewed from the arrow 1 direction in FIG.
have. In the illustrated example, the y cylinder is provided with a measured number of notch grooves. Master cam// is a master cam sleeve that can rotate on the main shaft and slide in the axial direction! + are formed in parallel in the axial direction. The master cam sleeve 21I has an index dog at the end thereof as the other member of the circumferential indexing fixture of the master cam // which engages with the index plate 23. The outer circumference of Index Plug Co. 3 is shown in Figure 3 as seen from the
It is expanded and shown in Figure H. master cam sleeve, 2
4t is equipped with an index crocodile as an indexing driven tool driven by a drive device lIo, a brake disc that engages with a braking device 6Q, and a control sleeve 2g that slides into the main shaft is fixed to 27. has been done.

Master cam sleeve, 21I and control sleeve: A ring that forms a circumferential groove between 1g and slides onto the main shaft y, 2? It accommodates. On the outer periphery of the ring 2q, there is one index plate of the indexing fixture, as shown in FIG. ? (7)/f groove, 23-/
-, the same number of notch holes 3/ are provided, and at the position where the index plug 3 is engaged with the index plate 23, the notch holes 3/ and the tips of the notches 3.2 are engaged. There is. The notch 32 is a notch member housed in a cylindrical member fixed to the control sleeve 2g, and its tip is pressed against the outer periphery of the ring λ by an internal spring, and when a certain torque or more is applied, the notch 32 The tip is pushed out from the notch hole 3/, and the control sleeve 2
This is a so-called friction positioner in which g starts rotating on the main axis.

A master cam drive pin 33 having a rectangular cross section is inserted into the ring 29 and is inserted into the long hole lla extending in the axial direction and diameter of the main shaft l. The long hole Jl'a extends in the axial direction and across the diameter of the rod 71I, and the slider 33 having a circular cross section is fitted in the center hole of the rod 3g so as to be freely movable in the axial direction. The slider 33 is a push spring 36
Install it opposite the small screw 3 screwed into the rod 3 through the .

A cylindrical rotating member 39 equipped with an index dog 3t that can be engaged with the index claw 26 is supported by a bearing groove on a flanged shaft sleeve that slides into the main shaft shaft, and is supported by a plate member fixed to the rotating member 3. The stopper pin lI is fixed to the 0-axis sleeve 4I/, which has the stopper 4/3 fitted into the circumferential groove of the uniaxial sleeve &/ to prevent the rotating member 39 from moving in the axial direction with respect to the uniaxial sleeve &/. The z end is #! ■Figure 3 of the expanded view from the arrow in Figure 2■ and ■-■ of Figure 2
As shown in the cross-sectional view, the rotating member 3? A coil spring 1IAr is inserted into the rotation member 3W arranged in the circumferential notch groove 39a, one end of the coil spring 3 is locked to the rotation member 39, and the other end is locked to the rotation member 39. is locked to the shaft sleeve /I/, and the shaft sleeve 4/ rotates together with the main shaft.
When the rotating member 39 is fixed, the coiled spring 3 is wound up.

The shaft sleeve drive pin 4t is inserted through the elongated hole lIb in the axial direction and across the diameter of the main shaft, and cross-fitted into the rod 34/.
A is fixed to the shaft sleeve/. cylindrical member 39,
The shaft sleeve pin/, the bearing lI+2, the stopper pin 3, the stopper pin, the winding spring, the shaft sleeve drive pin &4, etc. constitute the index drive device qo and move simultaneously in the axial direction of the main shaft pin.

A cylindrical guide member Gua is fixed to the pulley /6, and the rotational position of the guide member 4'7 is determined by degrees in correspondence with the switches LS-, 2 to LS-1 fixed on the outer periphery of the guide member Gua. Dogs D- to D3, which act on each other, are fixed. A slide yg is slid into the inner periphery of the guide member lever 7 so as to be able to move in the axial direction, and a connecting member lever 91 fixed to one end of the slide lIg is inserted so that the rod 34' touches the step at the end. It is fixed by inserting it into the rod 311 and screwing the lock nut into the male thread at the end of the shaft (l!).

Five bearing cases are fixed to the other end of the slide lIg,
Two thrust bearings sandwich the internal shoulder of the bearing case S2, and the piston rod &...? It is locked with a lock nut 37 that fits thickly into the piston rod jJa and is screwed into the end of the piston rod jJa. 3 and the three rods are on the same center line, and the rod 34t is relative to the piston 33.
forms a freely rotatable coupling joint 5Q that can rotate freely. The piston S3 is fitted into an intermediate piston Sg which is fitted into the hydraulic cylinder SS, and the piston 5J has a stroke that moves from the intermediate pistons t and rζ! It has a stroke that moves relative to t. That is, it is a known hydraulic cylinder that can be stopped in three positions.

Brake frame on rocking table 3! rq, 59 is fixed and the frame &? ,,! i? The brake bodies A and 2 slide into a guide bar 67 that is fixed to and arranged parallel to the main axis. There are movable brake pieces 6 on the brake body All.
3 is pivotally connected by a pin AII, and brake shoes Ak, L, and A are provided at one end of the movable brake piece O3 and one end of the brake body A, 2 so that the brake disc core can be compressed. The piston rod torque a end of the brake cylinder 6 fixed to the other end of the brake body 6 can suppress the other end of the movable brake piece 63. The piston rod A7a, which feeds compressed air into the brake cylinder A7, pushes the movable brake piece 63 and rotates clockwise around the pin 6g, causing the brake shoe t! 7'L/-Kiti disk 27 is braked by pressure from μ6I. When the brake cylinder 67 is released, braking stops. Brake body A
, 2 are movable brake pieces 63, brake shoes 6, t, l
, A, supports the brake cylinder A7 and moves in the axial direction of the master cam assembly Jθ to follow it.

In the present invention, two master cams are prepared for the intake and exhaust of the engine: a master cam IN for creating an intake cam and a master cam EX for creating an efgest cam. These phase differences are constant regardless of the number of cylinders.

Therefore, for example, in the case of a Hiro cylinder engine, a total of three master cams for intake and exhaust are required, but in the present invention, there are only two master cams. Similarly, in the case of a T-cylinder engine, a total of 72 intake and exhaust master cams are required, but only two are required.

When grinding the cam, piston S3 and intermediate piston rg
is located at the right end, the index plug 2.3- is fitted into the notch groove 23-/ of the index plate λ3, and the master cam assembly 30 is located at the right end. Also, the index dog 3g is fitted into the index claw 2A, the index drive device g0 is at the right end, and the stopper pin +<z is in the notch groove of the shaft sleeve 4'/? The side wall of 9a? ? The coiled spring 5 is wound up by the amount of rotation (I, 2) when it comes into contact with b.

First, the work W is fixed between both centers 7 and D, and the work drive metal 5 is engaged with the work W. As shown in FIG. 1, the phase of the intake cam/engine N is made to match the phase of the master cam IN. Next, the master cam IN is brought into contact with the follower roller/2. When motor lO is energized, pulley/6
rotates, the main shaft rotates, and the index plate, 2
From 3 to the index plug, IS and rotational force are transmitted to the master cam sleeve! 4 and the master cam l/ rotate integrally with the main shaft ke, the drive tool 6 rotates with the drive metal S to rotate the workpiece W, and the intake cam/work N is rotated by the grinding wheel/3. The follower roller 2 mounted on the table 1 performs copy grinding.

When the machining of the intake cam/N is completed, the master cam// is separated from the follower roller lλ by the retraction cylinder of the rocking table 3 having a concave path.

Next, index the grinding machine table to the position where the next exhaust cam/BX corresponds to the grinding wheel 73,
Furthermore, shift to the follower roller/collar master cam EX position and perform copy grinding with grinding wheel/3 in the same manner as above.

When the machining of the F-gist cam/FiX is completed, the master cam// is separated from the follower roller 7.2, and the grinding machine table/1 is moved in the longitudinal direction so that the inch-Fukamco IN of the workpiece W corresponds to the grinding wheel/3. At the same time, the follower roller/2 is shifted again to correspond to the master cam IN for creating the intake cam, and 71 star cam/l is indexed to the intake cam/engine N.
The phase angle between
00) with respect to the main shaft bow. This indexing rotation of the master cam // is performed in the following manner.

This will be explained with reference to the flowchart in FIG.

The indexing operation is performed while rotating the main shaft shaft.゛First, when 5QL-, 2 of the four-way switching valve E3V/ is excited, the cylinder 1! Pressure oil is fed into the cylinder chamber of r, t7L, and the piston S3 and intermediate piston 3g move to the left.

Then, the rod 3, which is rotating together with the main shaft, is moved to the left via the left universal rotary joint. As the rod 31I moves to the left, the shaft sleeve drive pink 6 moves to the left, and the indexing drive assembly lIo moves to the left. and index dog 3g
is released from the index claw 2B, and at the same time, the rotational member 3 moves on the shaft sleeve 11 by the left direction of the coiled spring.
9 rotates, and the index dog 3g rotates in the same direction as the rotation direction of the ball shaft D relative to the index claw 2A.
V, index dog 3g is at position 3g as shown in V
-/ to position 3g-2.・ On the other hand, the force of the push spring 36 pushes the pin 3 together with the slider 3.
3 moves to the left in the long hole of the main shaft.

Calling pin 3. ? Due to the left row of the ring 29, the control sleeve, 2g1 master cam IJ-p, 24'
Move to the left and index plate, 23 notch grooves, 2
The index plug 2 left is released from 3-/ (Fig. 3 ■). The pin 33 hits the left end wall of the long hole a of the main shaft,
In the state shown in FIG. 2, the master cam assembly 3θ stops moving in the axial direction. At this time, the master cam // is held by the notch 3λ so that the phase thereof is not shifted with respect to the circumferential direction of the main shaft. The rod 311 continues to retreat a little further, and the push spring 36 is compressed.

The long hole of rod 311? The pin 33 reaches the right side of 9a.The state in which the rod 3da has reached the rearward end is as shown in FIG.

The backward end of the rod 3'l is separated from the index forward end confirmation switch LS-g of the disk-shaped dog DA fixed to the bearing case 3.2 of the universal rotary coupling joint 50, thereby opening the switch and opening the dog DA. When the master cam approaches the rearward end confirmation switch LS-4 and turns on, the four-way selector valve SV/5QL-/ is energized, pressure oil is sent into the cylinder chamber jtgR, and the intermediate piston! The piston S3 is advanced to an intermediate position, and the rod 3'l is advanced through the universal joint SO.

The indexing drive device θ moves to the right, and the index dog 3g
moves forward to the position 3g-3 where it engages with the index claw 2B (Fig. 3 ■) 1. At this time, the master cam drive pin 3
3, even when the rod 3 moves to the right, the elongated hole J4'a only moves and does not move, and since the slider 35 is pushed to the left by the push spring 36, it is tailgated by the advancement of the rod 3'l. movement is prevented.

The index intermediate position based on the forward movement of the intermediate piston rg is the dog D7 formed in a cylindrical shape on the outer periphery of the dog DA.
operates the index intermediate position confirmation switch L8-7, and the signal from this switch energizes the three-way switching valve SV, 2, 5QL-4 for the brake via a control circuit (not shown), and compressed air is sent to the brake cylinder 67. entered,
The brake disc 27 is braked, causing the master cam assembly 30 to stop rotating, thus stopping the master cam//. The main shaft is notch 3.2 and notch hole 3/
Push up the notch 3 from the notch hole 3/ against the engagement of the notch 3 and continue rotating. Since the main shaft is still rotating due to the stop of the master cam, the shaft sleeve is a coiled spring! By rotating the cylindrical member 39 in the rotating direction of the main shaft l, the index leg 3g is moved from position 3g-3 to position 3g-'I by a distance L/ The index dog 3t moves and comes into contact with the index claw 26 which is stationary. Subsequently, the stopper pin 1III fixed to the shaft sleeve rotating together with the main shaft 3 is inserted into the notch groove of the rotating member 3q. 9a
The winding blade 11.3 is wound up until it collides with the side edge Job (distance lv#I,, 2 movements), and the index dog 3g moves to the next index claw, 24 for indexing.
The resilience needed to overcome this is stored. At this time, Notsuchi 3
This engages with the notch hole 3/ of the ring holder. The master cam l/ is shifted by a phase angle et o Q with respect to the main axis l.

At the same time, the dog D/ provided at one location on the circumference of the control sleeve KOJ makes the switch LS-/ for detecting the master cam top sense, and at the index position of the first cylinder of the engine, the dog D/2 and the switch for confirming the first cam position are activated. Switch LS-J and dog D, which determine the a-th cam position, are placed at a position 90 degrees out of phase from the position where LS-J was in agreement.
The switch LS-3 is activated in the coincident position. In response to the signals from the master cam top detection switch LS-/and the second cam position confirmation switch LS-, 3, the solenoid 5QL-, ? of the three-way switching valve SV3 is activated via a control circuit (not shown). is excited, and the pressure oil flows into the cylinder chamber j
When the piston j3 is properly fed to gA, the piston j3 moves forward, and the rod 31I moves further forward via the universally rotating joint SO. And the indexing drive device O and the long hole of the rod 311 already? Q
The master cam assembly 3o moves to the right through the pin 33 and the ring plate 9 which are in contact with the left end wall of the index plug, the index plate 2 on the left, the notch groove plate 3-. 2, the master cam l/ is indexed to the correct position and locked. And index plug, 25 is notch groove, 2.7-, i! When inserted, the index intermediate position can be confirmed by the right row of dog D7.
f Tsuchi LS-7 is cut off, and index forward end confirmation switch L8- is turned on, and in response to the signal from switch LB-g, three-way selector valve SV, 2, 5QL-+ are cut off, and brake cylinder 67 is disabled. pressure, and the braking device 6o is released. The indexing operation of the main shaft is performed by the drive tool 6.
It is conveyed to

Ko\ Teforo Arora 7.2 (!: Mama Master Cam l
It is possible to copy and grind the intake cam aIN using the master cam IN for creating the medium intake cam, and also copy and grind the next F-gist cam, 2FtX? [In 1, the rotation indexing operation of the master cam // is not necessary, and the follower roller 12
Processing can be done by simply shifting to the master cam EX side for creating the F-Gist cam.

Similarly, while rotating the master force A// at a predetermined angle to0 (in the case of the y cylinder) with respect to the main shaft G, the intake cams 3N, 4T N, and the F-gist cam, yl are rotated.
Grind X and qEX sequentially. As a result, each individual intake and efjst cam can be patterned and ground by a set of two master cams.

When grinding other types of cams, a set of two master cams, one for creating an intake cam and one for creating an F-ggest cam, can be installed in parallel on the master cam 77 group, and the follower rollers/, 2
All you have to do is change the position of the .

The explanation of the embodiment is about cam grinding for a four-cylinder engine, but in the case of cam grinding for a large cylinder, the only difference is that the index number is divided into six circumferential divisions. It is easy to use the same multiple cylinders, and the notch groove of the index plate can be used for multiple cylinders. For example, in the case of a four-cylinder engine and an inner cylinder engine, a notch groove may be provided at the bottom. The number of index claws is also the same as the notch grooves of the index plate.

As described above, the present invention includes one set of master cams for cam generation corresponding to one type of engine camshaft, and a large number of sets of master cams for cam generation to correspond to many types of engine camshafts. One member of the indexing fixture is supported by a sleeve that is movable and rotatable in the axial direction on the main shaft, and is movably driven in the sleeve by a rod inserted through the main shaft center hole on the main shaft. A master cam sleeve and a master cam assembly are provided at one end and constitute a driven member indexed by an indexing drive member mounted on the main shaft at the other end, the rotation of which is selectively stopped by a braking device. in the axial direction of the main shaft for rotationally biasing an indexing drive member which is axially movably mounted by the rod and is engageable with an indexing driven member at the other end of the sleeve of the master cam assembly. A rotary member is provided to rotate on the shaft sleeve via a coil spring with respect to the shaft sleeve, which is movable to the shaft sleeve, and the index drive member is provided at the end of the rotary member, and Stopper pin 1I4 (and notched groove jq) that limits rotation of the moving member to the phase angle of the cam
(1) The number of master cams for one type of workpiece is minimized because the rod drive device is arranged at the rear end of the main shaft and the necessary control device is provided.

(2) Master cams for many more F5i1JN workpieces can be incorporated than in the past.

(3) When grinding the engine cam, there is no variation in the profiles of the intake cam and master cam in each cylinder.

(4) When manufacturing a model cam, it is easy to manufacture a model cam because only the intake cam and exhaust cam/set need to be manufactured, and since there are few master cams, the number of machining can be reduced.

[Brief explanation of drawings]

Fig. 1 is a front view of the cradle part of a cam grinder, Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 3 is a partially developed view of Fig. 1, and Fig. 7 is a -■ sectional view and Figure S are control flowcharts. L: Grinding machine table K: Swing axis 3: Swing table
Ri...main axis!・・Drive part 6・・Drive tool 7・e center g・-Tailstock data center /θ・・motor l
/... Master Cam lkokenshofuoq Arora 13
-Self-grinding wheel /Gu Peru't-/! ;Ft,/
! 'O-φ stage pulley /6 book pulley /7@-belt /I. /9 Bearing stand Ko@Pulley 21,2...Bearing, No. 23 index plate: 13-/. 23-. 1--Notch groove -21I--Master cam sleeve, 2&Φ index plug 26+1・Index claw: 17@・Brake disc 2g
＠-Control sleeve Kowall11 ring 3θ-O Master cam assembly 3/Separate notch hole J, 2...notch 33...Master cam drive pin 34tII-Rod, ? fa...Long hole 3k...Slider 36...Press spring 37...Machine screw 3g...Index dog
3? ...Rotating member? ? a... Notch groove lIO... Index drive device Hiroshi... Shaft sleeve Guko... Bearing Da3... Stopper +P... Stopper pin +1... Coiled spring +A... Shaft sleeve drive pin Goku/Φ guide Part qg@-Slide lI9...Connecting member SO...
Freely rotating connection joint! l...Lock nut...Bearing case! 3-Fist piston Ta3a-Piston rod 5g...Thrust bearing Left and right...Hydraulic cylinder! r?
・・Lock nut, 1L-7L-・Cylinder chamber sg
...Middle piston! gA,! sgR・-Cylinder chamber
S9...Frame Otsu0...Brake device 6/...Guide bar A2...Brake body A3...Movable brake piece 6 pieces@-pin 6366...Brake shoe A7...
・Brake cylinder A... Headstock part B... Work mounting part W... Work /Eng. N-Gue N... Intake cam /EX~pBX ・War exhaust cam E..
Mastercam EX-, Mastercam. Patent applicant Nippei Sangyo Co., Ltd. Agent Arai - Department

Claims (1)

[Claims] l Seven sets of cams arranged in parallel in the axial direction are at the same and the same angular position, and each set of cams can grind many types of camshafts including multiple cams arranged at positions with different phases. A cam grinding machine is provided with a table placed movably in the axial direction of the camshaft, and a rocking table supported on the table so as to be swingable about an axis parallel to the table movement direction. It is equipped with a main shaft that is rotatably supported on a rocking table, supports one side of the workpiece, is equipped with a master cam, and is provided with a follower roller that comes into contact with one of the master cam groups and can be shifted in the axial direction. In this case, a rod is inserted into the spindle center hole and driven by an axial drive device arranged at the rear end of the spindle, and is movable in the axial direction. 3.
a multi-coupled master cam assembly, an indexing drive on the main shaft coupled to the rod, a braking device and a control device for braking the master cam assembly, and one of the circumferential indexing fixtures on the main shaft. The master cam assembly includes a circumferential indexing fixture between one end of the master cam sleeve carrying the master cam and slid onto the main shaft, and the other member of the circumferential indexing fixture between the master cam sleeve and the main shaft, and the other end of the master cam sleeve. The master cam sleeve is provided with another indexing driven tool that can be secured to the indexing drive tool of the indexing drive device, and the master cam sleeve is engaged with the rod via a resistance member against rotation, and the master cam sleeve is engaged with the rod through a resistance member against rotation. The indexing drive device is provided with a braking member, and the indexing drive device is connected in the rotational direction to a shaft sleeve fitted into the main shaft so as to be movable in the axial direction via a spring member, and the rotation angle is limited to the master cam phase angle. A cam grinder in which a cylindrical member is fitted with a stopper and an indexing drive at the end.