JPS5835804B2 - Collection chuck of workpieces with internal gears - Google Patents

Description

Detailed Description of the Invention The present invention relates to a collet chuck for gripping a workpiece having an internal gear, and its purpose is to grip the workpiece based on the pit-in pin diameter of the internal gear. be.

Generally, when machining the outer diameter of a workpiece having an internal gear, the workpiece must be rotated about the rotation center of the internal gear of the workpiece.

However, in conventional collet chucks, a collet provided concentrically on the outer peripheral surface of a draw rod is inserted into an inner hole in a workpiece where an internal gear is not formed, and this collet is moved by the movement of the draw rod. Since the workpiece is gripped by magnification, if the center of rotation of the internal gear and the center of the inner hole are even slightly misaligned, the workpiece will be held at a different point from the center of rotation of the internal gear. Since it rotates as a shaft, it has the disadvantage that machining based on internal gears cannot be performed accurately.

In addition, a method of gripping the workpiece by pressing a collet against the tips of the internal gear teeth of the workpiece was considered, but since gear machining is generally not done with the tips of the teeth as a reference, in this case too, the workpiece cannot be machined. The center of rotation of an object cannot be made to coincide with the center of rotation of an internal gear.

The present invention has been made to eliminate such drawbacks, and is characterized in that a pin is interposed between the collet and the internal gear of the workpiece to grip the workpiece.

Practical examples of the present invention will be explained below based on the drawings.

In FIG. 1, reference numeral 1 denotes a chuck body, and the right end of this chuck body 1 is provided with a tapered portion 11 whose diameter becomes narrower toward the right.
Five pin holes 14 having a diameter slightly larger than the diameter of the pin 13 into which the pins 3 are freely engaged are bored at equal intervals in the circumferential direction and corresponding to the number of pins 13.

2 is a draw rod inserted into the chuck body 1;
At the center of the draw rod 1, on the right side of the chuck body, there is provided a tapered part 21 whose diameter decreases in the direction of the main shaft 3, and at the right end there is a tapered part 21 for a drive that engages with the spline groove of the workpiece W. A spline 22 is formed.

Further, a drive pin 23 is screwed onto the left end of the draw rod 2, and when the draw rod 2 is held between a center 31 fitted to the main shaft 3 and a center 32 of the Shinjindai (not shown), the drive pin 23 is screwed onto the left end of the draw rod 2. The pin 23 is adapted to engage with a drive pin 33 screwed onto the main shaft 3.

Further, this draw rod 2 is provided with a male thread 24 that is screwed into the nut 4, and when the nut 4 is rotated clockwise, the taper portion 11 of the chuck body 1 connects to the taper portion 21 of the draw rod 2. be approached.

Furthermore, when the nut 4 is rotated counterclockwise, the engaging portion 42 of the engaging member 41 fixed to the nut 4 and the engaging groove 15 carved in the chuck body 1 are engaged with each other. , the tapered portion 11 of the chuck body 1 is connected to the tapered portion 2 of the draw rod 2.
It can be moved away from 1.

Reference numeral 5 denotes a collet held concentrically with the low rod 2, and tapered portions 5L5 provided at both ends of the inner surface of the collet 5.
2 are fitted into the tapered portion 11 of the chuck body 1 and the tapered portion 21 of the draw rod 2, respectively.

As shown in FIG. 2, this collet 5 has grooves 53 alternately formed at ten locations on the circumference, so that the collet 4 can be easily expanded.

The collet 4 is positioned relative to the chuck body 1 by an engagement pin 54 to prevent the pin 13 from falling into the moving groove of the collet 5.

Reference numeral 6 denotes a holding member that freely holds the tip end 13a of the pin 13, and this holding member 6 is fitted into the draw rod 2 with only rotation allowed.

This holding member 6 is formed into a pentagonal shape as shown in FIG. There is.

This retaining hole 61 and the pin hole 14 of the chuck body 1
The pin 13 is held between.

The engaging portion of the engaging hole 61 is provided with a taper 62 as shown in FIG.
4 is provided with a spring 16 that presses the pin 13 toward the holding member 6 and a pedestal 17.

Therefore, when the draw rod 2 moves to the right with respect to the chuck body 1 and the distance between the chuck body 1 and the engagement hole 61 becomes longer, the spring 16 expands and the tip 13a of the pin 13 moves into the holding hole. 61.

Furthermore, when the pin 13 is pressed radially outward by the collet 5, the tip 13a of the pin 13 overcomes the pressing force of the spring 16 and freely moves along the taper 62 of the engagement hole 61.

Furthermore, since the pin hole 14 of the chuck body 1 has a diameter larger than the diameter of the pin 13 as described above, the pin 13 can move freely as the collet 5 expands, and Closely attached to gears.

Next, the operation of gripping a workpiece W having an internal gear using the collet chuck having the above configuration will be explained.

Assuming that the draw rod 2 is in the state shown in FIG. 1 and the collet 5 is not expanded, the collet 5 can rotate relative to the draw rod 2.

As described above, the collet 5 is engaged with the chuck body 1 by the engaging pin 54, and the chuck body 1 is connected to the holding member 6 by the pin 13, so the collet 5, the chuck body 1, the pin 13, The holding member 6 can be rotated as a unit.

In this state, the workpiece W having an internal gear and a spline groove
When the collet chuck is inserted from the left side, the internal gear of the workpiece W engages with the pin 13 as shown in FIG. 3, and the spline groove of the workpiece W engages with the spline 2 of the draw rod 2.
2.

At this time, the phase between the internal gear and the spline groove of the workpiece W differs depending on the workpiece, but the pin 13 is
Since the pin 13 rotates relative to the pin 13, the internal gear and the pin 13 can be engaged regardless of the phase difference.

After inserting the collet chuck into the workpiece W in this manner, when the nut 4 is rotated clockwise, the taper portions 11 and 21 approach each other and the collet 5 is expanded.

As a result, the pin 13 is moved radially outward, but
If the phases of the five pins 13 provided on the chuck body 1 and the tooth grooves corresponding to these pins 13 do not all match, the pins 13 also move in the circumferential direction to correct this phase difference. As a result, the five pins 13 are brought into close contact with the internal gear.

Thereby, the workpiece W is gripped so that the rotation center of the internal gear and the axis of the draw rod 2 coincide with each other.

When the workpiece W is gripped as described above, the draw rod 2 is clamped between the center 31 of the main spindle 3 and the center 32 of the tailstock, and the outer peripheral surface of the workpiece W is machined by rotating the main spindle 3. .

As a result, the workpiece W is rotated around the rotation center of the internal gear, and accurate machining is performed using the internal gear as a reference.

Note that since the workpiece W is driven by the spline 22 formed on the draw rod 2, slipping will not occur even if the force applied between the taper portion 52 of the collet 5 and the taper portion 21 of the draw rod 2 is small. do not have.

Furthermore, if the force applied to the tapered portions 52 and 21 during machining of the workpiece W is smaller than the frictional force applied by tightening the nut 4, there is no need to provide the spline 22 on the draw rod 2, and the spline Even workpieces without grooves can be machined.

When the collet chuck is removed from the workpiece W after machining of the workpiece W is completed, it is sufficient to rotate the nut 4 counterclockwise, and as a result, the teniper parts 11 and 21 move away from each other, and the collet 5 becomes elastic. Shrinks at .

Therefore, the pin 13 is no longer pressed in the radial direction, and the grip on the workpiece W is released.

In this embodiment, the tip 13a of the pin 13 is tapered, and the spring 16
The pin 13 was held movably by pressing the tip 13a into the engagement hole 61 of the holding member 6, but as shown in FIG. 61 and longer than the movement range of the draw rod 2 relative to the chuck body 1 may be provided, and in this case, the spring 16 is not required.

FIG. 6 shows an embodiment in which the collet chuck of the present invention is installed on the main shaft and the draw rod is moved by a hydraulic cylinder. 01 The draw rod 2 is connected to a hydraulic cylinder 37 via a rod 36 that passes through the center of the main shaft 3.

Further, the draw rod 2 is engraved with a key groove 25 in the axial direction, and the chuck body 1 is screwed with a zero-rotation bolt 18 that engages with the key groove 25. rotates integrally with the chuck body 1.

For this reason, a pin hole 14 for holding the pin 13 is bored in a pin hole member 19 fitted to the outer peripheral surface of the chuck body 1, so that the pin 13 can freely rotate relative to the chuck body. ing.

Therefore, in this actual case, when the workpiece W is inserted from the right side, the pin hole member 19, pin 13, and holding member 6 rotate together, and the pin 13 engages with the internal gear.

Then, when pressure oil is supplied to the hydraulic cylinder 37 and the draw rod 2 moves to the left, the collet 5 expands and the workpiece W is gripped with the internal gear as a reference.

Note that in this embodiment, the collet 5 is connected to the draw rod 2.
When releasing the grip on the 01 workpiece W, the collet 5 is forcibly moved to the right.

As described above, in the collet chuck of the present invention, since the pin is interposed between the collet 5 and the internal gear of the workpiece W to grip the workpiece W, the diameter of the pit-in pin of the internal gear can be reduced. It has the advantage that the workpiece can be gripped using the internal gear as a reference, and the workpiece W can be accurately machined using the internal gear as a reference.

Furthermore, in the collet chuck of the present invention, the pin 13
Since the pin 13 and the internal gear are held in a freely movable manner, even if the pin 13 and the internal gear are not completely in phase with each other, the pin 13 can be brought into close contact with the tooth groove of the internal gear. This has the advantage that the rotation center of the gear can be precisely aligned with the main shaft axis.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the first practical example of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a view showing I in FIG.
[[-I cross-sectional view, FIG. 4 shows the pin 13 in FIG.
FIG. 5 is a partially enlarged view showing the holding structure of the holding structure, FIG. 5 is a second embodiment thereof, and FIG. 6 is a diagram showing an embodiment in which the collet chuck is attached to the main shaft. 1...Chuck body, 2...Draw rod, 3...Main shaft, 5...Collet,
6... Holding member, 11.21, 51, 52...
... Taper part, 13 ... Pin, 14 ...
...Pin hole, 16...Spring, 61...
...A workpiece having an engagement hole, W...an internal gear.

Claims (1)

[Claims] 1. A chuck body having a tapered part at the tip held concentrically with the main shaft, a draw rod inserted into the chuck body and having a tapered part outside the chuck body, and a draw rod held concentrically with the main shaft and having a tapered part outside the chuck body. a collet in which a taper portion provided at both ends of the surface fits into a taper portion provided on the chuck body and a taper portion provided on the draw rod; a plurality of pins movably held in the chuck body; a holding member provided on the draw rod to movably hold the tip of the pin, and the pin is interposed between the collet and an internal gear of the workpiece to grip the workpiece. A collet chuck for workpieces with a characteristic internal gear.