JPH11165248A - Grinding method of cam, grinding device, grinding wheel for grinding cam and its dresser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding method of a cam capable of applying high precision grinding treatment on a profile surface even on the tapered cam having the profile surface inclined against an axis of rotation. SOLUTION: Two of a grinding surface and a standard surface inclined so as to face against each other are provided on a peripheral surface of a grinding wheel 21. Original point positioning is carried out by making one end surface 15a of a flange 15 of a camshaft 11 on which a tapered cam 14 is provided and the standard surface contact with each other. A precise positional relation of the grinding wheel 21 and the tapered cam 14 in the axial direction is found by this original point positioning. Thereafter, grinding is carried out by moving the grinding wheel 21 in the axial direction of the camshaft 11 with this original point position and sliding and bring the grinding wheel 21 and the tapered cam 14 into sliding contact with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for grinding a cam provided on a camshaft, a grinding apparatus used for the method, a grinding wheel for cam grinding, and a dresser therefor. The present invention relates to a grinding method, a grinding apparatus, a grindstone, and a dresser shape suitable for grinding a cam having a tapered surface inclined at an inclination angle.

[0002]

2. Description of the Related Art In recent years, a multi-valve internal combustion engine having a plurality of intake valves or exhaust valves for each cylinder has been widely used as an automobile engine. According to this method, the intake / exhaust efficiency can be increased by increasing the opening area of the valve, and the inertial mass per valve can be reduced, so that the opening and closing of the valve at high rotation can be made smoother. it can.

Generally, in such a multi-valve internal combustion engine, intake valves or exhaust valves are arranged in parallel. However, due to strong demands on the performance of the internal combustion engine, there is a case where each valve is radially arranged. FIG. 10A shows an example of such a radial valve arrangement. When the valves are arranged radially, even between the intake valves 7 or between the exhaust valves 8,
Their axes are not parallel and open at a predetermined angle 2α. In FIG. 10A, a member 2 indicates a combustion chamber, and a member 3 indicates a piston.

[0004] The shape of the combustion chamber 2 is an important factor that greatly affects the performance of the internal combustion engine, such as the combustion efficiency and exhaust gas emission in the same chamber, but the shape is generally greatly restricted by the arrangement of valves. However, by arranging the valves radially as described above, the degree of freedom of the shape is increased, and the shape of the combustion chamber 2 can be improved.

[0005] Further, particularly in the case of an internal combustion engine for high output, high intake and exhaust efficiency is required. Therefore, it is desired to increase the opening area of each valve and increase the gas flow rate in the bore mask portion. However, since the area of the cylinder bore is limited, the shape of the combustion chamber may be damaged by enlarging the opening area of the valve. In addition, in this case, the narrow angle between the intake valve and the exhaust valve increases, so that the arrangement of the valve operating mechanism for opening and closing these valves is naturally restricted. Even in such a case, by adopting the radial valve arrangement as described above, it is possible to enlarge the opening area of the valve while suitably maintaining the shape of the combustion chamber and the narrow angle between the valves.

Further, by employing the above-described radial valve arrangement, it is possible to widen the interval between the valves, and it is possible to increase the efficiency of cooling the valve seat, the spark plug, and the like.

However, when such a radial valve arrangement is employed, the swinging directions of the respective valves are different from each other, so that it is difficult to design a valve operating mechanism for driving these valves. In particular, it is difficult to employ the radial valve arrangement in the case of a direct-acting lifter type valve operating mechanism in which a valve lifter is directly pressed by a profile surface of a cam provided on a camshaft to swing the valve. That is, in such a direct hit lifter type, a DOHC (double over head camshaft) type in which an intake valve and an exhaust valve swing with separate camshafts is generally adopted, Even in this DOHC format,
Since the swing axes of a pair of valves driven to open and close by one camshaft are inclined at a predetermined angle, a normal flat cam, that is, a cam in which the rotation axis of the camshaft and its profile surface are parallel to each other is used. The profile surface of the cam cannot abut at right angles to the pivot axis of the valve,
Smooth swinging of the valve becomes difficult.

Conventionally, a taper cam having a profile surface (taper surface) inclined with respect to the rotation axis of a camshaft so that the radial valve arrangement can be adopted even in such a direct-acting lifter type valve operating mechanism. A configuration in which the valve is driven to open and close by a valve is being studied. FIG. 11 (a)
(C) shows the structure of such a tapered cam 14. FIG. 11A shows the planar structure of the tapered cam 14, and FIG.
1 (b) shows a side structure, and FIG. 11 (c) shows a perspective structure.

In the tapered cam 14, the diameter of the base circle changes continuously along the axis of the camshaft 11. However, even if the diameter of the base circle changes, the lift height of the lift portion 14b does not change. By adopting such a tapered cam 14,
As shown in FIG. 10B, the profile surface 14a of the tapered cam 14 can be brought into contact with the pivot axis of the valve 7 at a right angle, and thus the radially arranged valves 7 can be brought into contact with each other. Can be smoothly swung.

[0010]

The opening and closing timings of the intake valve and the exhaust valve are determined by the profiles of the cams that drive those valves. High accuracy is required. In particular, in the case of the taper cam in which the profile surface itself is inclined with respect to its own axis, the grinding of the profile surface is very difficult, in combination with such high precision requirements.

Conventionally, the grinding of the profile surface of a general flat cam has been performed using a grinding device 50 as shown in FIGS. 12 (a) and 12 (b). FIG. 12A shows a side structure of the grinding device 50, and FIG. 12B shows a plan structure.

The grinding device 50 grinds the profile surface of the cam 13 provided on the camshaft 11 while rotating a substantially disc-shaped grindstone 51. The camshaft 11 is rotatably supported by a chuck 55 and a tailstock 56 provided on the work headstock 57, and is driven to rotate by the work headstock 57. The work headstock 57 and the tailstock 56 are mounted on the worktable 5.
8 is fixed. The grindstone 51 is a camshaft 11
The profile surface of the cam 13 is ground while advancing and retreating in the radial direction of the shaft 11 with the rotation of. The grindstone 51 is rotatably supported by a grindstone shaft 52 provided on a grindstone stand 53 so as to be integrally rotatable, and is rotationally driven by the grindstone stand 53.

On the other hand, the grinding apparatus 50 shown in FIG.
When grinding the tapered cam 14 as illustrated in FIG. 12, the cam may be inclined by inclining the grindstone shaft 52 as shown in FIG. 12C or by inclining the work table 58 to which the camshaft 11 is attached. A method of relatively inclining the rotation axis of the shaft 11 and the grindstone shaft 52 in accordance with the inclination of the profile surface of the cam 14 is adopted. However, in order to grind the tapered cam 14 by such a method, the grinding device 50 needs to have a function of inclining the grindstone shaft 52 or the work table 58.

Further, even in a grinding apparatus having no such function, the grinding wheel having a tapered surface inclined in accordance with the inclination angle of the profile surface of the tapered cam is used as a grinding surface, so that the tapered cam can be ground in a manner similar to the above. Can be done.

However, in any of these methods, the positioning of the grindstone and the tapered cam in the axial direction requires higher accuracy than the grinding of a general flat cam. This will be described in more detail with reference to FIG.

That is, in the case of the flat cam 13, FIG.
As shown in (a), the grindstone 51 and the cam 1 at the time of the grinding are used.
Even if the position of the cam 13 in the axial direction slightly deviates from the original position, no error occurs in the diameter of the profile surface 13a of the cam 13.

However, in the case of the tapered cam 14, as shown in FIG. 13B, the positional relationship between the tapered cam 14 and the grindstone 51 in the axial direction at the time of grinding is very important. That is, assuming that the position in the axial direction between the tapered cam 14 and the grindstone 51 is ground at a position shown by a two-dot chain line shifted by α from the original position shown by the solid line, the grinding surface 51a of the grindstone 51 Is cam 1
Since the cam 14 is inclined with respect to the axis 4, an error of β occurs in the radial direction of the profile surface 14a of the cam 14. As described above, when an error occurs in the diameter of the profile surface of the cam, valve characteristics such as the opening / closing timing of the valve and the lift amount thereof also change, so that the performance of the internal combustion engine is significantly affected.

Although FIG. 13B shows a case where the rotation axis of the taper cam and the rotation axis of the grindstone are relatively inclined for convenience, the positioning of the taper cam and the grindstone in the axial direction during such grinding is shown. The problem of accuracy also occurs in a grinding method using a grindstone having the inclined tapered surface as a grinding surface.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a high-precision grinding process for a tapered cam having a profile surface inclined with respect to the rotation axis. An object of the present invention is to provide a cam grinding method, a grinding device used for the grinding method, a cam grinding grindstone, and a dresser thereof.

[0020]

In order to achieve the above object, according to the first aspect of the present invention, the tapered surface of the tapered cam provided on the camshaft is ground by a grindstone having the same tapered surface and rotating. A cam grinding method, wherein an axial reference surface is provided on the grinding wheel, and an axial reference surface is also provided on the camshaft or its supporting portion, and the reference surfaces are brought into contact with each other to adjust the origin. After going,
The camshaft and the grindstone are relatively displaced in their respective axial directions to perform positioning in the axial direction.

According to this method, the axial reference surface provided on the grindstone and the axial reference surface provided on the camshaft or its support portion are brought into contact with each other, so that the axial origin can be adjusted. Done. By adjusting the origin, an accurate positional relationship between the grinding wheel and the camshaft can be grasped.
By moving the grindstone and camshaft relative to the axial direction based on the distance from the origin determined in this way,
The positioning between the grindstone and the tapered surface of the tapered cam ground by the grindstone can be accurately performed. Therefore,
It is possible to perform grinding with accurate positional relationship,
High-precision processing is guaranteed. The reference plane in the axial direction of the camshaft or its supporting portion can be set at an arbitrary position such as a protrusion in the camshaft or a chuck for supporting the camshaft. A base end surface of a flange usually provided at the distal end portion for suppressing the movement is particularly preferable in order to maintain high positioning accuracy in the axial direction.

According to a second aspect of the present invention, in the cam grinding method according to the first aspect, the tapered surface and the reference surface in the axial direction of the grinding wheel have a peripheral surface shape corresponding to the tapered surface and the reference surface. Is formed and re-formed each time a new grinding is performed by the dresser which rotates with the rotation.

According to this method, a decrease in precision caused by the deterioration of the grinding surface of the grindstone due to the grinding can be suppressed, so that the precision of the grinding is maintained. According to a third aspect of the present invention, in the cam grinding method according to the second aspect, the camshaft is provided with a plurality of tapered cams having tapered surfaces having different angles from each other, and the grinding wheel is provided with the tapered cams. A plurality of tapered surfaces corresponding to the respective tapered surfaces are formed. After each of the tapered surfaces of the tapered cams is ground by the grindstone, the tapered surface of the grindstone is re-formed by the dresser.

According to this method, a high-precision grinding process is guaranteed even for a camshaft provided with a plurality of tapered cams having tapered surfaces having different angles from each other. In addition, grinding can be performed as it is, without going through the process of replacing the grindstone or inclining the rotating shaft of the grindstone and the rotating shaft of the camshaft according to the angle of the tapered surface. An increase in the process or processing time can be suppressed.

According to a fourth aspect of the present invention, in the cam grinding method of the second aspect, the camshaft is provided with a plurality of tapered cams having a pair of tapered surfaces having tapered surfaces in opposite directions. The grindstone has two tapered surfaces corresponding to the tapered cams of the paired tapered cams, and the tapered surfaces of the paired tapered cams are ground by the grindstones. Is to reform.

According to this method, high-precision grinding is ensured even for a camshaft provided with a plurality of pairs of tapered cams having tapered surfaces in opposite directions. Also,
Depending on the angle of the tapered surface, it is possible to perform grinding in the same state without changing the grinding wheel or inclining the rotating shaft of the grinding wheel and the rotating shaft of the camshaft. It is possible to suppress an increase in processing time.

According to a fifth aspect of the present invention, in the method for grinding a cam according to the second aspect, the camshaft is provided with a mixture of the tapered cam and a flat cam having no tapered surface and the grinding wheel. A tapered surface corresponding to the tapered surface of the tapered cam and a parallel surface corresponding to the parallel surface of the flat cam are formed, and after grinding the tapered surface of the tapered cam and the parallel surface of the flat cam with the grindstone, respectively, The dresser reshapes the tapered and parallel surfaces of the grindstone.

According to this method, even a camshaft provided with a mixture of a tapered cam and a flat cam can be ground with a single grindstone, and further high-precision grinding is guaranteed. According to a sixth aspect of the present invention, in the cam grinding method according to the fifth aspect, the dresser includes a tapered dress surface forming the tapered surface of the grindstone and a parallel dress surface forming the parallel surface of the grindstone. In the meantime, a dresser having a vertical dress surface that forms the axial reference surface of the grinding wheel is used.

According to this method, the width of the dresser can be reduced. Therefore, interference between the dresser and other members is suppressed, and the degree of freedom of the arrangement of the dresser and the sliding range thereof are increased. Also, during dressing, the contact area between the dresser and the grindstone is reduced, so that the driving torque of the dresser is reduced.

In the invention according to claim 7, in the cam grinding apparatus, there is provided a work table which supports a camshaft provided with a tapered cam and an axial reference surface;
A grindstone table that supports a grindstone having a tapered surface and an axial reference surface, and an origin in the axial direction is set based on the contact between the camshaft's axial reference surface and the grindstone's axial reference surface. In addition, the work table and the grindstone are positioned in the axial direction based on the relative displacement of the work table and the grindstone table in the axial direction with respect to the set origin. A control device for controlling further relative displacement with respect to the table in a direction orthogonal to the axial direction, and at least a rotation driving mode of the grinding wheel.

According to this configuration, by bringing the axial reference surface provided on the camshaft into contact with the axial reference surface of the grindstone, the axial origin is set. The control device relatively moves the work table and the grindstone table in the axial direction with reference to the origin, and performs the axial alignment of the grindstone and the tapered cam ground by the grindstone. Further, the control device controls the rotational drive mode of the grindstone while relatively displacing the work table and the grindstone table in a direction orthogonal to the axial direction according to the shape of the tapered cam. In this way, it is possible to perform grinding in an accurate positional relationship, and high-precision grinding is guaranteed even for a camshaft provided with a tapered cam. Note that the reference surface in the axial direction of the camshaft can be set at an arbitrary position such as a projection in the camshaft or a chuck for supporting the camshaft, but in order to suppress the movement of the camshaft in the thrust direction. The base end surface of the flange usually provided at the distal end is particularly preferable in order to maintain the axial positioning accuracy at a high level.

According to the invention described in claim 8, in the cam grinding apparatus according to claim 7, the dresser for pivotally supporting a dresser having a peripheral surface shape corresponding to a tapered surface and an axial reference surface of the grinding wheel. Further comprising a table, wherein the control device further controls the relative displacement between the grindstone table and the dresser table and the rotational drive mode of the dresser to form and reshape the tapered surface and the axial reference surface of the grindstone. It is.

According to this configuration, the control device relatively moves the dresser table that supports the dresser having the peripheral surface shape corresponding to the tapered surface of the grindstone and the reference surface in the axial direction and the grindstone table, and Is brought into sliding contact with the tapered surface and the reference surface of the grinding wheel. And the control device:
The rotational drive mode of the grindstone and the dresser is controlled to dress the taper surface and the axial reference surface of the grindstone with the peripheral surface of the dresser. In this way, it is possible to suppress a reduction in processing accuracy caused by deterioration of the grinding surface of the grindstone due to the grinding process, so that the accuracy of the grinding process is maintained.

According to a ninth aspect of the present invention, in the cam grinding apparatus according to the eighth aspect, the control device is configured to control a dressing amount of the grinding wheel based on a relative displacement amount between the grinding wheel table and the dresser table. Accordingly, the relative displacement of the work table and the grindstone table in a direction orthogonal to the axial direction is corrected.

According to this configuration, in addition to the relative position of the grinding wheel and the cam ground by the grinding wheel with respect to the axial direction, the positioning accuracy of the relative position with respect to the direction orthogonal to the axial direction is also guaranteed, and as a result, high accuracy is achieved. Accurate grinding is guaranteed.

According to a tenth aspect of the present invention, there is provided a cam grinding wheel which is rotatably supported by a rotating shaft and grinds a cam profile surface based on its rotation, wherein one or a plurality of wheels are inclined with respect to the rotating shaft. And a reference surface in the rotation axis direction.

According to this configuration, a tapered cam having a tapered surface corresponding to the inclination of the surface can be ground on the tapered surface inclined with respect to the rotation axis. Further, it is possible to accurately grasp the positional relationship between the grinding stone and the taper cam in the rotation axis direction by using the reference surface in the rotation axis direction provided on the grinding stone.
Therefore, even with a camshaft provided with a tapered cam, high-precision grinding is guaranteed.

[0038] According to the eleventh aspect of the present invention, there is provided a cam grinding grindstone which is rotatably supported by a rotating shaft and grinds a cam profile surface based on its rotation, wherein one or a plurality of wheels are inclined with respect to the rotating shaft. Tapered surface, one parallel surface parallel to the rotation axis, and a reference surface in the rotation axis direction,
It is provided with.

According to this configuration, the tapered cam can be ground by the tapered surface of the grindstone, and the flat cam can be ground by the parallel surface. Further, it is possible to accurately grasp the positional relationship in the rotation axis direction between the grinding stone and the cam to be ground by the reference surface in the rotation axis direction provided on the grinding wheel. Therefore, even with a camshaft provided with a mixture of a tapered cam and a flat cam, high-precision grinding is guaranteed.

According to a twelfth aspect of the present invention, in the cam grinding wheel of the tenth or eleventh aspect, the reference surface is provided in a manner orthogonal to the rotation axis.

According to this configuration, since the reference plane is orthogonal to the rotation axis, the alignment in the rotation axis direction can be performed easily and accurately. Further, in the invention according to the thirteenth aspect, the dresser is a dresser that is supported by a rotating shaft and dresses a grinding wheel for cam grinding that performs grinding of a cam profile surface based on the rotation thereof, wherein the dresser is inclined with respect to the rotating shaft. A plurality of tapered dress surfaces and a reference surface dress surface forming a reference surface in the rotation axis direction are provided.

According to the above configuration, even if the grinding wheel has a tapered surface inclined with respect to the rotation axis and a reference surface in the direction of the rotation axis,
It is possible to easily perform dress processing and form and re-form these surfaces.

According to a fourteenth aspect of the present invention, there is provided a dresser for supporting a cam grinding grindstone which is rotatably supported by a rotating shaft and grinds a cam profile surface based on the rotation of the dresser. One or a plurality of tapered dress surfaces, one parallel dress surface parallel to the rotation axis, and a reference surface dress surface forming a reference surface in the rotation axis direction.

According to the above configuration, dressing can be easily performed even with a grindstone having a tapered surface inclined with respect to the rotation axis, a parallel surface parallel to the rotation axis, and a reference surface in the direction of the rotation axis. It is possible to form and re-form these surfaces.

Further, in the invention according to claim 15, the reference surface dress surface is provided between the tapered dress surface and the parallel dress surface. According to the same configuration,
The width of the dresser can be reduced, interference between the dresser and other members is suppressed, and the freedom of arrangement of the dresser and the sliding range thereof are increased. Further, the contact area between the dresser and the grindstone during dressing is also reduced, so that the driving resistance of the dresser is reduced.

According to a sixteenth aspect of the present invention, in the dresser for a cam grinding wheel according to the thirteenth, fourteenth, or fifteenth aspect, the reference surface dressing surface is provided in a manner orthogonal to the rotation axis. .

According to this configuration, it is possible to form and re-form a reference plane perpendicular to the rotation axis of the grindstone.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows the structure of a camshaft 11 provided with a tapered cam 14 to be ground in this embodiment. In addition, this camshaft 11 is a 4
It is used as a camshaft of a cylinder engine,
Four pairs of tapered cams 14 having profile surfaces (tapered surfaces) inclined so as to face each other are provided. The camshaft 11 may be either an intake-side camshaft or an exhaust-side camshaft. Here, a case where the camshaft 11 is used as an intake-side camshaft will be described. A flange 15 serving as a support portion in the thrust direction when the camshaft 11 is mounted on an upper portion of a cylinder head of an engine (not shown) is provided on a tip end (left end in FIG. 1) of the camshaft 11.
Is provided. In the present embodiment, the base end surface 15a of the flange 15 is used as a positioning reference surface when the camshaft 11 is machined or assembled into an internal combustion engine. That is, the camshaft 11
The components such as each of the cams 14 provided on the
Are arranged with reference to a distance in the axial direction from the reference surface 15a.

Next, the configuration of a grinding apparatus for grinding the profile surface of the tapered cam 14 of the camshaft 11 will be described with reference to the schematic diagram shown in FIG. The grinding device 20 mainly includes a work table 30 to which the camshaft 11 as a workpiece (work) is attached, a grindstone table 34 to which the grindstone 21 is attached, and a dresser 26.
And a control device 36 for controlling them.

On the work table 30, a headstock 33 provided with a chuck 31 for fixing the distal end side of the camshaft 11, and a tailstock 3 supporting the base end side of the shaft 11 are provided.
2 are provided. The camshaft 11 is attached to the worktable 30 with the distal end side on which the flange 15 is formed fixed by a chuck 31 so as to be integrally rotatable, and the base end supported by the tailstock 32.
When the camshaft 11 is attached, the phase in the rotation direction about the axis of the shaft 11 and the chuck 31 is accurately determined by the unevenness or the like (not shown).
The camshaft 11 and the chuck 31 are rotated by the headstock 33. This rotation is controlled by the control device 36, and the rotation phase can be accurately adjusted.

The grindstone 21 is attached to the grindstone table 34 via a grindstone shaft 22. This whetstone table 3
4 rotates the grinding wheel 21 and the grinding wheel shaft 22,
The cam shaft 11 can be moved relative to the work table 30 in the axial direction (the left-right direction in FIG. 2) and the radial direction (the up-down direction in FIG. 2). The movement of the grindstone table 34 and the rotation of the grindstone 21 are also controlled by the control device 36.

The dresser table 35 has a dresser shaft 2
The dresser 26 is attached through the sash 7. The dresser table 35 can also rotate the dresser 26 and the dresser shaft 27 and move in the axial direction and the radial direction of the camshaft 11 with respect to the work table 30. The rotation and movement are also controlled by the control device 36. Is done.

The control device 36 controls the work table 3
0, the positional relationship between the grindstone table 34 and the dresser table 35 is always accurately grasped, and the exact shape of the profile surface of the tapered cam 14 where the grinding is performed, that is, the same profile surface at a predetermined rotation phase of the camshaft 11 The distance from the axis of the shaft 11 is stored as numerical data.

The camshaft 11 and the grindstone 21 described above are used.
The rotation axes of the dresser 26 and the dresser 26 are arranged to be parallel to each other. Next, the structure of the grinding wheel 21 and the dresser 26 will be described with reference to FIG.

As shown in FIG. 3B, the grindstone 21 has a substantially disk shape as a whole, and a central portion of a peripheral surface thereof corresponds to a profile surface of a pair of tapered cams 14 to be ground. A pair of grinding surfaces (tapered surfaces) 23a and 23b inclined at an angle are formed. In addition,
The ground surfaces 23a and 23b have a configuration in which the center is convex. Further, these ground surfaces 23a and 23
Surfaces perpendicular to the rotation axis of the grindstone 21 are formed at both ends of b. Of these surfaces, the surface 24 on the tip end side of the grindstone 21 is a reference surface for axial positioning described later. ing.

Originally, the grindstone 21 is provided as a simple disk shape as shown by a two-dot chain line in FIG. 3 (b). The grinding surfaces 23a and 23b and the reference surface 24 are formed. The surface of the grindstone 21 before the dressing process has some unevenness. Therefore, in order to perform high-precision grinding or to use the side surface of the grindstone 21 as a positioning reference surface, it is necessary to perform dressing and smooth the surface.

FIG. 3A shows a dresser 26 used for dressing the grindstone 21. This dresser 2
6 also has a substantially disk shape, and its peripheral surface has a dress surface 2.
8a, 28b and 29 are formed. The dressing surfaces 28a, 28b are ground surfaces 23a, 23b of the grindstone 21.
In addition, the dress surface 29 corresponds to the reference surface 24 of the grindstone 21, and is formed such that when the peripheral surface of the grindstone 21 and the peripheral surface of the dresser 26 are brought into sliding contact, the corresponding surfaces coincide with each other. In addition, these dress surfaces 28a, 28b and 29
Is coated with high-hardness particles such as diamond powder, so that the surface of the grindstone 21 can be dressed without difficulty.

Next, the grinding process by the grinding device 20 will be described with reference to FIGS. In addition,
This grinding process is performed as a finishing process of the profile surface of the tapered cam 14 after the rough machining of the camshaft 11 is completed.

First, prior to grinding, the camshaft 11 is mounted on the work table 30 by the chuck 31 and the tailstock 32. Further, the control device 36 moves the dresser table 35 to bring the peripheral surface of the dresser 26 into sliding contact with the peripheral surface of the grindstone 21. At this time, the dressing of the peripheral surface of the grindstone 21 is performed by rotating the grindstone 21 and the dresser 26 in the same direction. Thus, on the peripheral surface of the grindstone 21, the grinding surfaces 23a and 23b and the reference surface 24 are formed or reformed.

After the dressing of the grindstone 21, the control device 36 moves the grindstone table 34 or the work table 30 so that the reference surface 24 of the grindstone 21 and the reference surface 15 a provided on the end surface of the flange 15 of the camshaft 11 abut. Let it.
The controller 36 stores the position of the grindstone table 34 or the work table 30 in the axial direction at this time as a reference position (origin).

Thereafter, the control device 36 moves the grindstone table 34 or the work table 30 using the stored reference position as the origin in the axial direction, and the profile surface of the taper cam 14 to be ground and the corresponding ground surface 23 of the grindstone 21.
a or 23b is brought into sliding contact.

By the way, depending on the mounting state of the camshaft 11 or the grindstone 21, etc., the work table 30
The positional relationship between the grinding wheel table 34 and the grinding wheel 21 and the positional relationship between the grinding wheel table 34 and the grinding wheel 21 may not be reproduced as expected. At this time, if the grinding is performed by moving the grindstone table 34 based on the positional relationship between the work table 30 and the grindstone table 34, for example, the positional relation between the taper cam 14 and the grindstone 21 is not correctly reproduced, and FIG. As described above, an error may occur in the diameter of the profile surface after grinding.

In this respect, the camshaft 11 of the present embodiment
By providing reference surfaces 15a and 24 on the grindstone 21 and performing axial alignment with them, the axial position of the tapered cam 14 to be ground and the grindstone 21 can be accurately matched with a desired position. Becomes possible.

Thereafter, the profile surface of the tapered cam 14 is ground while rotating the grinding wheel 21 at a high speed and simultaneously rotating the camshaft 11. At this time, the control device 36 slides the grindstone 21 back and forth in the radial direction of the camshaft 11 in accordance with the required value of the distance between the profile surface and the axis based on the data on the diameter of the profile surface of the cam 14 described above. Let it. Thus, an accurate profile surface is formed.

In this manner, the pair of tapered cams 14 are ground on the corresponding ground surfaces 23a and 23b. Thereafter, the dressing of the grindstone 21 is performed again, and the grinding surfaces 23a and 23b and the reference surface 24 are formed again. Then, the camshaft 11 and the grindstone 21 are again positioned to determine the reference position, and then the next pair of tapered cams 14 are ground. By repeating such a series of steps by the number of pairs of the tapered cams 14, the grinding of the camshaft 11 is completed.

Incidentally, at the time of grinding, the abrasive grains fall off from the ground surface and the grindstone itself is worn away, so that the processing accuracy gradually deteriorates. Therefore, it is necessary to re-form the ground surface by the dresser 26 every time the taper cam 14 is newly ground. On the other hand, when the taper cam 14 is ground by the grindstone 21 having the tapered surfaces 23a and 23b as the grinding surfaces as described above, the positioning accuracy of the dresser 26 and the grindstone 21 in the axial direction is very important even during this dressing. That is, in the dressing, if an error occurs in the axial position between the dresser 26 and the grindstone 21 from the original position, an error also occurs in the diameter of the grinding surfaces 23a and 23b of the grindstone 21.
The error in the diameter of the ground surfaces 23a and 23b thus generated is naturally reflected on the cam 14 to be ground, resulting in an error in the diameter of the profile surface. In this regard, in the present embodiment, the camshaft 1 is attached to the grindstone 21 during dressing.
1 is formed. Then, each time the dressing is performed, the positioning between the grindstone 21 and the camshaft 11 is performed. Therefore, the grinding can always be performed with an accurate positional relationship.

Although the diameter of the grindstone 21 is gradually reduced by the dressing process, the control device 36 grasps the amount of the dressing of the grindstone 21 from the positional relationship between the grindstone table 34 and the dresser table 35 during the dressing process. The position of the grindstone 21 in the radial direction of the tapered cam 14 to be ground at this time is corrected according to the dress amount. Therefore, it is possible to perform grinding while always maintaining the radial position of the grindstone 21 and the tapered cam 14 to be ground accurately, and it is possible to maintain processing accuracy.

As described above, according to the present embodiment, the following effects can be obtained. -Since the grinding wheel 21 and the tapered cam 14 to be ground can be accurately positioned, the profile surface of the cam 14 can be ground with high precision.

2) The inclination angles of the grinding stones 21 are opposite to each other.
Since the grinding surfaces (tapered surfaces) 23a and 23b of the surfaces are provided, the pair of tapered cams 14 can be ground as they are without replacing the grindstone or turning the grindstone table. Therefore, the number of processing steps and the processing time can be reduced, and the processing cost can be reduced.

The two grinding surfaces 23a and 23b of the grinding wheel 21
Each time the pair of tapered cams 14 are ground, that is, the dressing is performed by the ground surfaces 23a and 23b each time one tapered cam 14 is ground, the accuracy of the profile surface of the cam 14 is improved. be able to.

Two grinding surfaces 23 formed on the grinding wheel 21
Since a, 23b and the reference surface 24 can be dressed in one process, the number of dressing processes and the number of processes can be reduced. Therefore, the processing time is reduced, the wear of the dresser 26, and the wear of the grindstone 21 are suppressed.
As a result, processing costs can be reduced.

The grinding device 20 of the present embodiment has substantially the same configuration as the conventional grinding device except for some changes such as the shape of the dresser 26. Therefore, the function equivalent to that of the grinding apparatus 20 of the present embodiment can be provided only by modifying a part of the conventional apparatus.

The present embodiment can be implemented by changing the configuration as described below. In the above embodiment, the two grinding surfaces 23a of the grindstone 21
Although 23b and 23b are formed so that the center becomes convex, as shown in FIG. 4A, they may be formed so that the center becomes concave. In this case, as shown in FIG. 4A, the shape of the dresser 26 is also changed so as to match the shape of the grindstone 21 described above. With this configuration, the same effect as in the above embodiment can be obtained.

In the above embodiment, a surface perpendicular to the rotation axis of the grindstone 21 is formed at both ends of the peripheral surface of the grindstone 21. However, such a surface is required. FIG. 4 shows only the tip side where the reference surface 24 is provided.
As shown in (b), a configuration in which a vertical surface is formed only on the tip side may be adopted. In this case, the shape of the dresser 26 is changed as before. According to the configuration, in addition to the effects of the above-described embodiment, the widths of the grindstone 21 and the dresser 26 can be reduced. (Second Embodiment) In a camshaft for an automobile engine, there is a case where both a tapered cam and a flat cam are provided. FIG. 5 shows an example of a camshaft provided with such two types of cams.

The camshaft 12 is used as an exhaust camshaft of a DOHC four-cylinder four-valve engine, and has profile surfaces inclined so as to face each other, like the camshaft 11 shown in FIG. Four pairs of tapered cams 14 are provided. Also,
A flange 15 is provided on the distal end side of the camshaft 12, and the base end side of the flange 15 serves as a reference surface 15a, similarly to the camshaft 11 in FIG. However, a flat cam 16 for a pump, which is a so-called flat cam, whose profile surface is parallel to the axis, is provided on the base end side of the camshaft 12.

The flat cam 16 for the pump is used for driving a fuel pump for pumping fuel to a delivery pipe. FIG. 6 shows a schematic configuration of a high-pressure fuel system of an engine including the fuel pump 17. The fuel pump 17 includes a plunger 18 urged against a pump flat cam 16 by a coil spring. The flat cam 16 for the pump has two lift portions, and the camshaft 1
The plunger 18 is reciprocated with the rotation of 2.

In addition to the above-described structure, there may be a case where the flat cam 13 and the tapered cam 14 are mixed, such as a five-valve engine in which three intake valves 7 are provided in one cylinder shown in FIG. is there. In the present embodiment, a description will be given of a grinding process for a camshaft in which such two types of cams are mixed, taking the case of the camshaft 12 shown in FIG. 5 as an example.

In this embodiment, the same or corresponding components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The different portions will be mainly described.

In the grinding according to the present embodiment, only the shape of the dresser 26 is changed, and otherwise, the grinding apparatus 20 according to the first embodiment is used as it is. FIG.
(A) shows the shape of the dresser 26 and the peripheral surface of the grindstone 21 formed by the dresser 26 in the present embodiment. The dresser 26 and the grindstone 21 have a substantially disk shape, similarly to the first embodiment, and are fixed to be integrally rotatable with the dresser shaft 27 and the grindstone shaft 22, respectively.

On the peripheral surface of the grindstone 21, two grinding surfaces 23 a and 23 b inclined at an angle corresponding to the profile surface (taper surface) of the tapered cam 14 and an axis for grinding the flat cam 16 for pump are provided. Parallel grinding surface 23c
Are formed. In the following, the grinding surfaces 23a, 2
The tapered ground surface and the ground surface 23 are inclined as shown in FIG.
What is parallel to the axis, such as c, is referred to as a parallel ground surface. A surface 24 perpendicular to the axis of the grindstone 21 is formed at the tip end (left side in FIG. 8A) of the grindstone 21, and is used for positioning in the axial direction during grinding. It is the reference plane.

On the other hand, the peripheral surface of the dresser 26 is
The dress surfaces 28a, 28b,
28c and 29 are formed. The dress surface 28
a, 28b, and 28c correspond to the tapered grinding surfaces 23a and 23b and the parallel grinding surface 23c of the grindstone 21, respectively, and the dress surface 29 corresponds to the reference surface 24 of the grindstone 21.

The grinding process of this embodiment is the same as that of the first embodiment except that the profile surface of the flat cam 16 for the pump is ground by the parallel grinding surface 23c of the grinding wheel 21. Done in When grinding the flat cam 16 for the pump, after positioning is performed in the same manner as in the case of the tapered cam 14, the grinding wheel table 34 or the work table 30 is moved, and the profile surface of the cam 16 is moved by the parallel grinding surface 23c. Grind. Then, dresser 28
Is brought into sliding contact with the grindstone 21 to perform dress processing.

According to the present embodiment described above, the following effects can be obtained. Since the grinding wheel 21 can be precisely positioned with the tapered cam 14 to be ground and the flat cam 16 for the pump, the profile surfaces of these cams 14 and 16 can be ground with high precision.

The grinding wheel 21 has tapered grinding surfaces 23a, 23a
b and the parallel grinding surface 23c which is parallel to the axis is provided, so that the flat cam and the taper cam are provided in a mixed state without changing the grindstone or turning the grindstone shaft or the grindstone table. Grinding can be performed on the camshaft. Therefore, the number of processing steps and the processing time can be reduced, and the processing cost can be reduced.

The tapered grinding surfaces 23a and 23b of the grindstone 21
Each time a pair of tapered cams 14 or a flat cam 16 for a pump is ground on the parallel grinding surface 23c, dressing is performed, so that the accuracy of the profile surfaces of these cams 14, 16 can be improved.

The two tapered grinding surfaces 23a, 23b, the parallel grinding surface 23c and the reference surface 24 formed on the grinding wheel 21.
Can be processed in one step, so that the number of dress processing and the number of steps can be reduced. Therefore, the processing time can be reduced, the wear of the dresser 26 and the consumption of the grindstone 21 can be suppressed, and the processing cost can be reduced.

The grinding device 20 of the present embodiment has substantially the same configuration as the conventional grinding device except for some changes such as the shape of the dresser 26. Therefore, the function equivalent to that of the grinding apparatus 20 of the present embodiment can be provided only by modifying a part of the conventional apparatus.

The present embodiment can be implemented by changing its configuration as follows. It is only necessary that two tapered ground surfaces, one parallel ground surface, and a reference surface are formed on the peripheral surface of the grindstone 21. The arrangement is not limited to the configuration of the above-described embodiment. As shown in (b) to (d), they may be arranged in any order. When such a change is made, the shape of the peripheral surface of the dresser 26 is naturally changed to match the shape of the peripheral surface of the grindstone. (Third Embodiment) This embodiment relates to grinding of a camshaft 12 provided with a flat cam 16 for a pump as shown in FIG. 5, as in the second embodiment. This embodiment is the same as the second embodiment except for the shape of the dresser and the grindstone and the dressing process. Therefore, the same or corresponding components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted, and different portions will be mainly described.

FIG. 9 (a) shows the peripheral shapes of the grindstone 21 and the dresser 26 according to the present embodiment. A tapered grinding surface 23a, a tapered grinding surface 23b, and a parallel grinding surface 23c are formed on the peripheral surface of the grindstone 21 in order from the tip side (the left side in FIG. 9A). Further, the tapered ground surfaces 23a and 23b are arranged in such a manner that the center is concave.

On the other hand, the peripheral surface of the dresser 26 is parallel to the parallel grinding surface 2 of the grindstone 21 from its base end (left side in FIG. 9A).
Dress surface 28c corresponding to 3c, similarly tapered ground surface 2
Dressing surface 28a corresponding to 3a, similarly tapered ground surface 2
3b are arranged in the order of the dress surface 28b. In addition, a step is provided between the dress surface 28c and the dress surface 28a, and an end surface 29 of the step is a dress surface corresponding to the reference surface 24 of the grindstone 21. .

The grinding process in this embodiment is performed in the same manner as in the second embodiment except for the dressing process. Hereinafter, the dressing process of the grindstone 21 by the dresser 26 will be described with reference to FIGS. 9B and 9C.
It will be described based on.

First, as shown in FIG. 9B, the peripheral surface of the dresser 26 is brought into sliding contact with the peripheral surface of the tip side portion of the grindstone 21.
The reference surface 24, the tapered ground surface 23a, and the tapered ground surface 23b of the grindstone 21 are dressed, and these surfaces are formed or reformed. Thereafter, the dresser 26 is moved to bring the dress surface 28c into sliding contact with the portion of the parallel grinding surface 23c on the tip side of the grindstone 21. While dressing the parallel grinding surface 23c, as shown in FIG. 9C, the dresser 26 is moved to the base end side of the grindstone 21 (the right side in FIG. 9C).
To perform dress processing on the entire grinding surface 23c.

Even when the dresser 26 has the above-described shape, it is possible to dress the same grindstone as in the second embodiment. Moreover, the width of the parallel grinding surface 23c is reduced by employing a configuration in which the parallel grinding surface 23c is dressed while being moved.

According to the present embodiment described above, the following effects can be obtained in addition to the effects of the second embodiment.・ Because the width of the dresser 26 has been shortened,
The degree of freedom of arrangement can be increased, and the dresser 2
6 can be expanded.

Further, by reducing the width of the dresser 26, the driving resistance during dressing can be suppressed, and the required rotational torque can be reduced. The present embodiment can be implemented by changing the configuration as described below.

The peripheral shapes of the grindstone 21 and the dresser 26 may be changed as shown in FIG. 9D so that the tapered ground surfaces 23a and 23b of the grindstone 21 are arranged to be convex. However, with such a configuration, the tapered ground surfaces 23a, 23b can be used during dressing of the parallel ground surface 23c.
And dresser 26 may interfere with each other. Therefore, in this case, instead of performing the dressing process on the parallel grinding surface 23c from the distal end side of the grindstone 21 as in the above-described embodiment, the dressing process is performed while moving from the base end side of the grindstone 21. desirable.

Further, each of the above embodiments can be implemented by changing the configuration as described below. In the above embodiments, the cam is ground while rotating the camshaft, but the camshaft is fixed and the cam is ground while turning the grindstone with respect to the axis of the camshaft. May be.

In each of the above embodiments, the reference surface for positioning on the camshaft side is provided on one end surface of the flange. However, if the positional relationship with the cam to be ground can be accurately grasped. The reference plane may be provided anywhere. This includes not only camshafts but also chucks and the like. If the reference surface is provided on a part other than the camshaft, the mounting accuracy of the camshaft should be increased
A device for accurately grasping the positional relationship between the mounted camshaft and the reference surface is required.

The reference surface on the grindstone side is not limited to the tip of the peripheral surface of the grindstone as in the above-described embodiments, but may be any place where the positional relationship with each ground surface can be accurately grasped. It may be provided. In addition, if the reference surfaces are brought into contact with each other at a point or a side such as a corner, the reference surfaces need not necessarily be orthogonal to the rotation axis.

The grinding device may not be provided with a dresser. For example, a dresser device for dressing a grindstone may be provided as a separate body, a large number of grindstones dressed in the above-mentioned manner by the device may be prepared in advance, and these grindstones may be replaced each time grinding is performed. In addition, the grinding wheel may be disposable, and the grinding wheel may be replaced every time the grinding is performed. However, when high processing accuracy is required, the frequency of replacing the grindstone increases, and there is a concern that the processing step or processing time may increase. Therefore,
As in each of the above embodiments, it is desirable that the grinding apparatus be provided with a dresser.

Depending on the configuration of the camshaft to be ground, only one tapered ground surface formed on the grinding wheel peripheral surface may be provided, or three or more tapered ground surfaces having various inclination angles may be provided. It may be. In this case, the shape of the dresser is also changed according to the shape of the grindstone.

In addition, technical ideas other than the above-mentioned claims that can be understood from the above embodiments are listed below together with their effects. (B) The relative movement of the first rotating shaft and the second rotating shaft in the axial direction or a direction perpendicular to the axial direction, or the rotational drive mode of the grinding wheel and the dresser is performed by numerical control. Claim 7 to Claim 9
A cam grinding device according to any one of the above.

According to this configuration, it is possible to more precisely align the grindstone with the surface to be ground, and it is possible to further improve the processing accuracy of the surface to be ground. (B) The cam according to any one of claims 1 to 6, wherein the axial reference surface provided on the camshaft or the support portion thereof is an end face of a flange portion of the camshaft. Grinding method.

(C) The cam grinding device according to any one of claims 7 to 9, wherein the reference surface in the axial direction of the camshaft is an end surface of a flange portion of the camshaft.

According to the method described in (b) and the configuration described in (c), the end surface of the flange portion of the cam shaft and the reference surface in the axial direction of the grindstone are brought into contact with each other, so that The origin is aligned with the grinding wheel in the axial direction. Since the end surface of the flange portion of the camshaft serves as a reference for axial alignment when the shaft is assembled to an internal combustion engine, it often becomes the axial origin in the design or processing of the shaft. Therefore, by using the end surface of the flange portion as a reference surface, more precise positioning can be performed, and the processing accuracy of the profile surface of the cam can be improved.

[0107]

According to the first aspect of the present invention, it is possible to accurately align the grindstone with the tapered surface of the tapered cam ground by the grindstone. By performing the grinding process with an accurate positional relationship in this manner, the accuracy of the process can be improved.

According to the second aspect of the present invention, a decrease in the processing accuracy caused by the deterioration of the grinding surface of the grindstone accompanying the grinding is suppressed, and the accuracy of the grinding can be maintained.

According to the third aspect of the present invention, a high-precision grinding process can be performed on a camshaft provided with a plurality of tapered cams having tapered surfaces having different angles.

According to the fourth aspect of the present invention, even if the camshaft is provided with a plurality of pairs of tapered cams having tapered surfaces in opposite directions, high-precision grinding is ensured. .

According to the fifth aspect of the present invention, even a camshaft in which a tapered cam and a flat cam are provided together can be ground with a single grindstone, and high-precision grinding is guaranteed. You.

According to the invention described in claim 6, the width of the dresser can be reduced. Therefore, interference between the dresser and other members is suppressed, and the degree of freedom of the arrangement of the dresser and the sliding range thereof can be increased.

According to the seventh aspect of the present invention, it is possible to perform grinding in an accurate positional relationship, and it is possible to perform high-precision grinding even for a camshaft provided with a tapered cam. .

Further, according to the invention described in claim 8, a decrease in the processing accuracy caused by the deterioration of the grinding surface of the grindstone accompanying the grinding is suppressed, and the precision of the grinding can be maintained.

According to the ninth aspect of the present invention, in addition to the relative position of the grinding wheel and the cam ground by the grinding wheel with respect to the axial direction, the relative position of the grinding wheel with respect to the direction orthogonal to the axial direction is adjusted. Accuracy is also guaranteed, and high-precision grinding is also guaranteed.

According to the tenth aspect of the present invention,
Even a camshaft provided with a tapered cam can perform high-precision grinding. According to the eleventh aspect of the present invention, a highly accurate grinding process can be performed even for a camshaft in which a tapered cam and a flat cam are provided in a mixed manner.

According to the twelfth aspect of the present invention,
Positioning in the rotation axis direction can be easily and accurately performed. According to the thirteenth aspect of the present invention, even with a grindstone having a tapered surface inclined with respect to the rotation axis and a reference surface in the direction of the rotation axis, dressing is easily performed, and these surfaces are formed and re-formed. Can be formed.

According to the fourteenth aspect of the present invention,
Even if the grindstone has a tapered surface inclined with respect to the rotation axis, a parallel surface parallel to the rotation axis, and a reference surface in the direction of the rotation axis, dressing is easily performed to form and re-form these surfaces. It can be formed.

According to the fifteenth aspect of the present invention,
The width of the dresser can be reduced. Claim 1
According to the invention described in Item 6, it is possible to form and re-form a reference surface perpendicular to the rotation axis of the grindstone.

[Brief description of the drawings]

FIG. 1 is a plan view showing a structure of a camshaft to be processed in a grinding method and a grinding apparatus according to a first embodiment.

FIG. 2 is a schematic diagram showing a schematic configuration of a grinding device according to the embodiment;

FIG. 3 is an exemplary sectional view showing the shapes of a grindstone and a dresser according to the embodiment;

FIG. 4 is a schematic view showing another example of the shape of the grinding wheel and the dresser.

FIG. 5 is a plan view showing a structure of a camshaft to be machined in a grinding method and a grinding apparatus according to a second embodiment.

FIG. 6 is an explanatory diagram showing a use state of a flat cam provided on the camshaft.

FIG. 7 is a schematic diagram showing a cam shape in a five-valve engine.

FIG. 8 is a schematic diagram showing shapes of a grindstone and a dresser according to the second embodiment.

FIG. 9 is an explanatory diagram showing shapes of a grindstone and a dresser and a dressing process according to a third embodiment.

FIG. 10 is a schematic diagram showing a configuration of radially arranged valves.

FIG. 11 is an explanatory view showing the shape of a tapered cam.

FIG. 12 is a schematic view showing a conventional grinding device.

FIG. 13 is an explanatory diagram showing a positional relationship between a cam and a grindstone during grinding.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Intake side camshaft, 12 ... Exhaust side camshaft, 13 ... Flat cam, 14 ... Taper cam, 14b ... Profile surface, 15 ... Flange, 15a ... Reference surface, 16 ... Pump cam, 20 ... Grinding device, 21 ... Whetstone, 23, 23
a, 23b, 23c: grinding surface, 24: reference surface, 26: dresser, 27: dresser shaft, 28a, 28b, 28c ...
Dress surface, 30: Work table, 33: Headstock, 34
... Whetstone table, 35 ... Dresser table, 36 ... Control device.

Claims (16)

[Claims] 1. A cam grinding method for grinding a tapered surface of a tapered cam provided on a camshaft with a grindstone which also has a tapered surface and rotates, wherein said grindstone is provided with an axial reference surface. An axial reference surface is also provided on the camshaft or its supporting portion, and after the reference surfaces are brought into contact with each other to adjust the origin, the camshaft and the grindstone are relatively displaced in their respective axial directions. A grinding method for a cam, wherein the positioning is performed in the axial direction. 2. A taper surface and an axial reference surface of the grinding wheel are dressed by a dresser which rotates with a peripheral surface shape corresponding to the taper surface and the reference surface, each time a new grinding is performed.
The method of claim 1 wherein the cam is formed and reformed. 3. The cam grinding method according to claim 2, wherein the camshaft is provided with a plurality of tapered cams having tapered surfaces having different angles, and the grindstone corresponds to each tapered surface of the tapered cams. A cam grinding method comprising: forming a plurality of tapered surfaces; grinding the tapered surfaces of the tapered cams with the grindstone; and re-forming the tapered surfaces of the grindstone with the dresser. 4. The method of grinding a cam according to claim 2, wherein the camshaft is provided with a plurality of tapered cams having tapered surfaces in mutually opposite directions, and the grinding wheel is provided with a pair of tapered cams. Two tapered surfaces corresponding to each tapered surface of the tapered cam are formed, and after grinding the tapered surfaces of the tapered cams forming the pair by the grindstone,
A cam grinding method, wherein the dresser reshapes a tapered surface of the grinding wheel. 5. A cam grinding method according to claim 2, wherein said camshaft is provided with a mixture of said tapered cam and a flat cam having no tapered surface, and said grinding wheel corresponds to a tapered surface of said tapered cam. A tapered surface to be formed and a parallel surface corresponding to the parallel surface of the flat cam are formed, and after grinding the tapered surface of the tapered cam and the parallel surface of the flat cam with the grindstone, respectively, the tapered surface and the parallel surface of the grindstone are parallelized by the dresser. A cam grinding method characterized by reshaping a surface. 6. A vertical dress as the dresser, wherein the reference surface in the axial direction of the grindstone is formed between a tapered dress surface forming the tapered surface of the grindstone and a parallel dress surface forming the parallel surface. The cam grinding method according to claim 5, wherein a dresser having a surface is used. 7. A worktable for supporting a camshaft provided with a tapered cam and an axial reference surface, a grinding wheel table for supporting a grinding wheel having a tapered surface and an axial reference surface, and a shaft of the camshaft. Based on the contact between the direction reference surface and the axial reference surface of the grinding wheel, the origins in the axial direction are set, and the axial direction of the work table and the grinding wheel table with reference to the set origin. Positioning in the axial direction based on the relative displacement to the, further relative displacement of the work table and the grindstone table in a direction perpendicular to the axial direction at this position, and at least the rotational drive of the grindstone A control device for controlling an aspect, comprising: a grinding device for a cam. 8. The cam grinding apparatus according to claim 7, further comprising a dresser table for pivotally supporting a dresser having a peripheral surface shape corresponding to a tapered surface of the grinding wheel and an axial reference surface. A cam grinding apparatus characterized in that a relative displacement between the grinding wheel table and the dresser table and a rotation driving mode of the dresser are further controlled to form and re-form a tapered surface and an axial reference surface of the grinding wheel. 9. The apparatus according to claim 6, wherein the controller is configured to move the work table and the grindstone table in a direction orthogonal to the axial direction according to a dress amount of the grindstone based on a relative displacement between the grindstone table and the dresser table. The cam grinding device according to claim 8, wherein the relative displacement is corrected. 10. A grinding wheel for cam grinding which is supported by a rotating shaft and grinds a cam profile surface based on the rotation thereof, comprising: one or a plurality of tapered surfaces inclined with respect to the rotating shaft; A grinding wheel for cam grinding, comprising: a reference surface; 11. A cam grinding grindstone that is supported by a rotating shaft and grinds a cam profile surface based on rotation thereof, wherein the grinding shaft includes one or more tapered surfaces inclined with respect to the rotating shaft. A grinding wheel for cam grinding, comprising: one parallel surface that is parallel; and a reference surface in the rotation axis direction. 12. The cam grinding wheel according to claim 10, wherein the reference surface is provided in a manner orthogonal to the rotation axis. 13. A dresser for supporting a cam grinding grindstone that is supported by a rotating shaft and grinds a cam profile surface based on the rotation thereof, wherein the dresser includes one or more tapered dress surfaces inclined with respect to the rotating shaft. A dresser for a grinding wheel for cam grinding, comprising: a reference surface dress surface forming the reference surface in the rotation axis direction. 14. A dresser which is supported by a rotating shaft, and which dresses a grinding wheel for cam grinding which grinds a cam profile surface based on rotation thereof, wherein the dresser has one or more tapered dress surfaces inclined with respect to the rotating shaft. A dresser for a grinding wheel for cam grinding, comprising: a single parallel dress surface parallel to the rotation axis; and a reference surface dress surface forming a reference surface in the rotation axis direction. 15. The dressing surface of the reference surface is provided between the tapered dressing surface and the parallel dressing surface.
Dresser for the described grinding wheel for cam grinding. 16. The reference surface dress surface is provided so as to be orthogonal to the rotation axis.
Dresser for the described grinding wheel for cam grinding.