JPH0230826B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cam grinder for grinding a cam of a camshaft.

An object of the present invention is to perform highly accurate cam grinding by rotation around the journal portion of the camshaft with a simple structure.

A conventional cam grinder supports the camshaft at both centers, and performs cam grinding using these centers as a reference. In this type of equipment, run-out occurs between the center hole and journal part due to pre-processing.
In the case where grinding is performed using the center hole as a reference, the deflection directly appears as a deflection of the base circle of the cam relative to the journal portion, and highly accurate cam grinding cannot be achieved.

For this reason, recently, as disclosed in Japanese Patent Application Laid-Open No. 144955/1983, the journal portions at both ends of the camshaft are held with chucks, etc., and the central journal portion is supported by a rest device, whereby the camshaft is supported. A cam is being developed in which the cam is ground while rotating around the journal to prevent the base circle of the cam from wobbling relative to the journal.

However, in the above device, there is a slight misalignment between the rotational axis of the chuck device and the support axis of the rest device, and the journal portions at both ends of the camshaft and the central journal portion are rotated and ground around separate axes. There was a problem in which it was difficult to obtain high-precision cam grinding.

In the present invention, a plurality of rest devices are installed in the axial direction between a headstock and a tailstock to support a plurality of journal parts of a workpiece at least at two points in the lower and lateral directions. The rest device that supports the journal part on the tailstock side is a rest device that supports at three points in the vertical and lateral directions, and a first engaging member that engages with the center hole of the workpiece is provided on the floating member, and A driving member is provided on the floating member to engage with the workpiece and transmit rotation, and the floating member is guided so as to be minutely movable in a plane perpendicular to the rotational axis of the spindle and in the rotational direction of the floating member and the spindle. A guide member to be engaged is provided on the main shaft,
A cam grinding machine is provided in which a floating device is provided between a second engaging member and a tailstock so that the second engaging member can float in the radial direction following the center hole of a workpiece.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a traverse table, 2 is a headstock, and 3 is a rocking table supported on the traverse table 1 so as to be swingable. A main shaft 4 is rotatably mounted above one end of the rocking table 3, and a tailstock 19 is fixedly mounted above the other end of the rocking table 3 at a position facing the main shaft 4. The main shaft 4
A large number of master cams 5 are fitted into the holder, and the rocking table 3 and the main shaft 4 are integrally swung back and forth in accordance with the profile of the master cams 5 by contacting follower rollers (not shown). . 23 is a three-point rest device that supports the journal portions at both ends of the camshaft W, and 24 is a two-point rest device that supports the center journal portion of the camshaft W. Both are arranged on the rocking table 3. There is.

Further, as shown in FIG. 4, a spring (floating device) 21 is fixed in the axial direction on the axial center line at the tip of the ram 20 of the tailstock 19, and the other end surface of the camshaft W is attached to the tip of the spring (floating device) 21. An engagement ball (second engagement member) 22 that engages with the center hole is fixedly provided. A spring (floating device) 21 allows the engagement ball (second engagement member) 22 to float in the radial direction.

Further, in the three-point rest device 23, as shown in FIG. 5, a rest arm 25 is pivotably supported on a rest device main body 24 fixed on a rocking table 3, using a pivot pin 31 as a fulcrum, so as to be able to swing open and close. The rest device main body 24 is provided with a lower rest shaft 26 that is moved forward and backward by an adjustment knob 28, and a lower shoe 27 is attached to this. Further, above the lower rest shaft 26, a central rest shaft 33 is connected to an adjustment knob 35.
A side shoe 34 is attached to the tip of the shoe. Further, an upper shoe 32 is attached to the rest arm 25, and the journal portion of the camshaft W is supported at three points by the upper shoe 32, the side shoe 34, and the lower shoe 27. Note that 29 and 36 are long holes, 30 and 37 are fixing bolts, and 38 is an operating rod for the rest arm 25. Furthermore, since the two-point rest device has the same configuration as the three-point rest device, except that it does not have the rest arm 25, its explanation will be omitted.

As shown in FIGS. 2 and 3, the front portion of the main shaft 4 is provided with a mechanism that engages one end of the camshaft W in a floating manner and transmits rotation. That is, a mounting plate 6 is fixed to the end of the main shaft 4, and a drive face plate 7 is attached to this mounting plate 6. A support metal 8 is brazed to the end face of this driving face plate 7, and a floating member 9 is in contact with this metal support metal 8.
This floating member 9 is held by a connecting link 10 pivotally attached to the end face of the drive face plate 7 so as to be able to float in a plane orthogonal to the rotational axis of the main shaft 4, and is further fixed at three locations on the end face of the drive face plate 7. The main shaft 4 is guided by the guide members 11a, 11b, and 11c so as to be able to move minutely within a plane orthogonal to the axis of rotation of the main shaft 4. Moreover, the guide members 11a, 11b, 1
1c and the floating member 9 can be engaged with each other in the rotational direction.

A drive member 12 is fixed to the floating member 9, and an engagement groove 13 is formed in the drive member 12, in which an engagement pin 14 protruding in the axial direction is engaged on one end surface of the camshaft W. There is. Further, a second positioning engagement member 18 is fixed on the same axis as the main shaft 4 and engages with a center hole in one end surface of the camshaft W to regulate the axial position of the camshaft W.

Further, a support member 15 is fixed to the floating member 9 so as to face the drive member 12 . This support member 15 is provided with a support piece 16 and a pressing piece 17 that come into contact with the outer diameter of the journal portion J at one end of the camshaft W.

As an example of a design modification of the above mechanism, as shown in FIGS. 6 and 7, a structure may be adopted in which the drive member 12a itself grips the journal portion J at one end of the camshaft W instead of the support member 15. In this case, a driving piece 39 is provided protruding from the driving member 39, and this driving piece 3
9 is formed with an engagement groove 13a for the engagement pin 14. The drive member 12a is provided with a support hole 43 that contacts three points on the outer diameter of the camshaft W, and a tightening piece 41 with a split groove 40 carved on the side of the center line of this support hole 43. 41 is tightened with a clamp bolt 42.

Since the present invention has the structure as described above, in the case of the embodiment shown in FIGS. 2 and 3, the rest device 2
One end of the camshaft W, which supports the journal portion at 3 and 24, is supported in contact with the support piece 16 and the pressing piece 17 of the support member 15, and the engagement pin 14 engages with the engagement groove 13 of the drive member 12. Moreover, the center hole engages with the positioning engagement member 18, and its axial position is regulated. Therefore, it is held by the drive face plate 7 via the floating member 9 so as to be able to float. On the other hand, the center hole at the other end of the camshaft W is engaged with and supported by an engagement ball 22 at the end of a spring 21 attached to the tip of the ram 20 of the tailstock 19.

When the main shaft 4 is rotated in such a supported state, the main shaft 4
The rotation is transmitted to the engagement pin 14 via the mounting plate 6, drive face plate 7, floating member 9, and drive member 12, and the camshaft W is rotationally driven. At this time, if there is misalignment between the center of the main shaft and the support axes of the rest devices 23, 24, the floating member 9 will float to self-correct, and the camshaft W will be moved to the journal portion supported by the rest devices 23, 24. The cam is rotated around the center and cam grinding is performed.

The same effect as described above can be obtained in the embodiment shown in FIGS. 6 and 7, but in this case, one end of the camshaft W is inserted into the support hole 43 of the drive member 12a and tightened with the clamp bolt 42. This embodiment differs from the embodiments shown in FIGS. 2 and 3 in that the operation of tightening the piece 41 is performed.

As described above, according to the present invention, since the journal part on the headstock side and the journal part on the tailstock side are rotatably supported at three points in the vertical and lateral directions, the cam part is rotated around the journal part. can be machined, resulting in the effect of improving the machining accuracy of the cam part. In addition, since the first engaging member and the second engaging member are engaged with the center holes formed at both ends of the workpiece, when the grindstone is separated from the workpiece, three
The advantage of the point rest device is that there is no risk of the workpiece flying out in the radial direction during rotation. Furthermore, the first
Since the engaging member and the second engaging member can float in a plane perpendicular to the rotational axis of the main shaft, there is a deflection between the journal part and the center hole, that is,
This has the effect of absorbing machining errors in the center hole.

[Brief explanation of drawings]

Fig. 1 is a partially sectional front view of the cam grinder of the present invention, Fig. 2 is a sectional view of the front part of the main shaft, Fig. 3 is a sectional view taken along the line shown in Fig. 2, and Fig. 4 is a sectional view of the tailstock. A side view of the tip of the ram, FIG. 5 is an enlarged cross-sectional view of FIG. 1 taken along the line, FIG. 6 is a cross-sectional view showing another example of the front part of the main shaft, and FIG. 7 is a cross-sectional view taken from FIG. 6 taken along the line. FIG. 1... Traverse table, 2... Headstock, 3
...Rocking table, 4...Main shaft, 5...Master cam, 6
... Mounting plate, 7 ... Drive face plate, 9 ... Floating member, 10 ... Connection link, 11a, 11b,
11c... Guide member, 12, 12a... Drive member, 13, 13a... Engagement groove, 14... Engagement pin, 15... Support member, 18... Positioning engagement member, 19... Tailstock , 20... Ram, 21... Spring, 22... Engagement ball, 23, 24...
Rest device, 40... Division groove, 41... Tightening piece, 4
2... Clamp bolt, 43... Support hole.

Claims (1)

[Claims] 1 The workpiece is rotatably supported by engaging the first engaging member of the headstock and the second engaging member of the tailstock with the center holes formed at both ends of the workpiece, and the workpiece is rotatably supported. Relatedly, in a cam grinding machine that grinds a cam portion of a workpiece by moving the workpiece relatively toward and away from a grindstone, at least a plurality of journal portions of the workpiece are held between the headstock and the tailstock. A plurality of rest devices are installed in the axial direction that support at two points in the lower and lateral directions, and among these rest devices, rest devices that support at least the journal part on the headstock and tailstock side are installed at three points in the upper, lower, and lateral directions. The first engaging member is provided on a floating member, and the floating member is provided with a driving member that engages with the workpiece and transmits rotation, and the floating member is connected to the rotational axis of the main shaft. A guide member is provided on the main shaft to allow minute movements in orthogonal planes and to engage with the floating member in the rotating direction of the main shaft, and the second engaging member is caused to flow in the radial direction following the center hole of the workpiece. A cam grinding machine characterized in that a floating device is provided between a second engaging member and a tailstock so as to enable grinding.