JPH0574715U - Key chuck - Google Patents

Abstract

(57) [Summary] [Structure] The axis of the work W fixed to the spindle 10 and the spindle 10
Device 20 that clamps by aligning with the axis of
And a key groove 25C formed in the work W as a phasing reference in camshaft and crankshaft grinding.
And a reference key 25 for engaging with the reference key 2
Reference numeral 5 is composed of a handle portion 25B which is thin in the radial direction of the main shaft 10 and an engaging portion 25A at the tip thereof, and the thin handle portion 25A is elastically deformable in the radial direction of the main shaft 10. [Effect] Even if an error occurs in the position of the key groove 25C of the work W, the reference key 25 elastically deforms in the radial direction of the spindle 10 to absorb the error. Can be matched and clamped. Therefore, defective grinding can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key chuck device having a reference key that engages with a key groove formed as a phase determination reference at a work shaft end in a camshaft or crankshaft grinder.

[0002]

[Prior Art]

 In grinding the camshaft or crankshaft, the reference key fixed to the chuck device is also eccentric with respect to the axis so that it engages with the key groove formed at the position eccentric with respect to the axis as a reference for phase determination at the shaft end of the work. With the reference key and the key groove of the work engaged, clamping is performed by the chuck device so that the axis line of the fixed spindle of the chuck device matches the axis line of the work. ..

[0003]

[Problems to be solved by the device]

 If there is a positional error in the key groove formed at the shaft end of the work, the chuck device will not be able to align the spindle and the work axis to clamp them, and the grinding accuracy will deteriorate, resulting in poor grinding. Therefore, strict precision guarantee is required.

[0004]

[Means for Solving the Problems]

 A chuck device that is rotatably supported on the headstock and a chuck device that is fixed to the end surface of the spindle and that clamps the shaft end of the workpiece by aligning the axis line of the spindle with the axis line of the workpiece and the workpiece shaft end. The reference key engages with a key groove formed eccentrically, and the reference key engages with the key groove at a tip end of the handle portion, which is elastically deformable in the radial direction of the main shaft. And a reference key having an engaging portion.

[0005]

[Action]

 The key groove formed at the end of the work shaft is engaged with the engaging portion of the reference key, and the end of the work shaft is clamped by the chuck device. At this time, if there is an error α in the key groove position, the handle portion of the reference key is elastically deformed in the radial direction according to the error α due to the clamping force when clamping.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 10 is a main shaft, and a positioning shaft 15 is provided in the center of the main shaft 10 for aligning the shaft center with O and for axially positioning the work W. The main shaft 10 is provided with a gear (not shown). It is rotationally driven around the axis O by a motor.

A chuck device 20 is fixed to the tip surface 11 of the main shaft 10 concentrically with the axis O. The chuck device 20 includes a chuck body 21, a collet 24 provided inside the chuck body 21 for gripping a shaft end of a work W, and a sleeve for expanding and contracting the collet 24 by moving in the axial direction of the main shaft 10. 23 and a reference key that engages with the end surface of the work W.

An inner hole 22A centered on the axis O and a collet operating cylinder 22B are formed in the chuck body 21, and a piston 35 formed at the rear end of the sleeve 23 is slidable in the cylinder 22B. Has been inserted into. In addition, oil passages 41 and 42 from the main shaft 10 are formed in the chuck body 21, and communicate with the oil chambers 30 and 40 sandwiching the piston 35 in the cylinder 22B, respectively.

The collet 24 has a thin-walled cylindrical shape at the center, the rear end is fixed to the chuck body 21, and holds the work W from the tip to the position P as shown in FIG. It is divided into two claws 24P. A taper T engaging with the sleeve 23 is provided on the outer periphery of the tip of the claw 24P.₂Are formed. The sleeve 23 has a taper T of the claw 24P on the inner peripheral surface.₂Taper T engaging with ₁ Is formed and is slidably inserted in the axial direction of the main shaft in an annular hole formed by the inner hole 22A and the cylinder 22B formed in the chuck body 21 and the collet 24. Scale 24.

As shown in FIG. 3, the reference key 25 has a handle 25B in which a height h in the radial direction of the main shaft 10 is thin and a hole 25D is formed, and an engaging portion 25A formed at the tip thereof. It is fixed to the hanging portion 21A formed in the central portion of the chuck body 21 such that the shaft center is located at a position eccentric from the axis O by ε. The reference key 25 can be elastically deformed only in the radial direction of the main shaft 10 by its thin handle portion 25B as shown by the dotted line, and the engaging portion 25A at the tip can change its position in the radial direction of the main shaft. In the circumferential direction of the main shaft (lateral direction in FIG. 3 (C)), there is a wall thickness that can maintain the specified rigidity. Since the reference key 25 has the hole 25D, it can help the handle portion 25B to elastically deform in the radial direction of the main shaft 10, so that the handle portion 25B can be shortened.

The operation of the above configuration will be described below. As a reference for phasing, there is a work W in which a key groove 25C is formed at a position eccentric from the axis O at the shaft end. The work W is engaged with the engaging portion 25A and the key groove 25C, and the positioning shaft It is brought into contact with 15 for axial positioning. The oil passages 41 and 42 cause a pressure difference in the oil chambers 30 and 40 of the cylinder 22B to operate the piston 35. When the sleeve 23 is slid in the X ₁ direction, the six pawls 24P are evenly bent inward by the action of the tapers T ₁ and T ₂ , and the axis of the work W and the spindle 10 are separated from each other. The claws 24P clamp the shaft end of the work W by matching the axes.

If there is an α error in the position of the key groove 25C of the work W, when the key groove 25C and the engaging portion 25A are engaged and clamped as described above, the clamping force of the reference key 25 causes The handle portion 25B elastically deforms according to the error α, and the engaging portion 25A at the tip absorbs the error α and is clamped. In the above-mentioned embodiment, the reference key 25 may be only a thick handle without the hole 25D, and the reference key 25 and the key reference 25C are thin and elastically deformable pins and pins in the radial direction of the spindle 10. It is also possible to replace it with a hole and drive by pin.

[0013]

[Effect of the device]

 The key chuck of the present invention has a structure in which a reference key having an engaging portion formed at the tip of a handle portion that is elastically deformable in the radial direction of the main shaft is engaged with a key groove formed in a work to be clamped. Even in a work having an error in the groove position, the reference key is elastically deformed in the radial direction of the spindle to absorb the error, so that the axes of the spindle and the work can be aligned and clamped. Therefore, since the keying abnormality can be prevented, the grinding accuracy and the phase angle accuracy can be improved, and the grinding failure can be reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a front view of the embodiment of the present invention.

FIG. 3 is an external view of a reference key.

[Explanation of symbols]

 10 Spindle 15 Positioning Axis 20 Chuck Device 21 Chuck Body 22B Cylinder 23 Sleeve 24 Collet 24P Claw 25 Reference Key 25A Engagement Part 25B Handle 25C Key Groove 25D Hole

Claims (1)

[Scope of utility model registration request] 1. A spindle rotatably hindered by a spindle stock,
A chuck device that is fixed to the end surface of the main shaft and that clamps the shaft end of the work by aligning the axis of the main shaft with the axis of the work, and a reference key that engages with a key groove formed eccentrically to the work shaft end. In a key chuck comprising: a reference key, the reference key includes a handle portion that is elastically deformable in a radial direction of the spindle, and an engaging portion that is formed at a tip of the handle portion and engages with the key groove. Characteristic key chuck.