JPS62130110A - Collet chuck - Google Patents

Abstract

PURPOSE:To enable the adjustment of the stroke of a collet chuck and adjustment of the reference surface of a stopper by providing a spacer and said stopper inside said collet chuck, in a collet chuck for turning. CONSTITUTION:In a collet chuck 3 installed in a chuck body 1 which is installed to a main spindle 2, an outside diameter taper part 4 is engaged with the inside diameter taper part 5 on the inner periphery of the body 1, and the collet chuck 3 is opened and closed by means of a draw bar 16 via a connecting part 8. And, a spacer 13 is inserted in a through hole 11 provided on a step side wall part 10 in between the barrel part 6 and the barrel part 9 of the collet chuck 3 and, further, a stopper 12 is installed to a tapped hole 14 with a bolt 15. The end face of the stopper 12 serves as a reference surface that keeps a right angle to an axis. By replacing a spacer 13, the stroke of a chuck cylinder, i.e. a chuck grip moving range can be varied. Also, the form of the stopper is simple enabling accurate positioning of a workpiece.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a collet chuck equipped with a stopper that accurately determines the desired longitudinal dimension of a workpiece in turning processing.

(Prior Art) Specifically, the present invention is capable of selecting and adjusting an appropriate chuck stroke while maintaining high accuracy in sizing in the longitudinal direction based on one end surface of a workpiece. This invention relates to a collet chuck in which a stopper is housed within the collet chuck.

Generally, the following two types of mechanical stoppers can be considered as a mechanical stopper that is attached to a collet chuck and has a function of determining the relative position in the axial direction by coming into contact with one end surface of the workpiece. One is that the stopper reference surface in the axial direction can be adjusted by inserting it into the entire length of the main shaft from the rear part of the main shaft and finely adjusting the nut.The second is that the stopper mounting part is inserted into the main shaft through the slotted part of the collet chuck. The former stopper type, which is exposed to the outside from the part and fixed to the spindle end or the chuck body (cap), is mainly used for machining small items when considering the use of collets, and the spindle diameter is generally small. Due to limitations on the spindle diameter, the stopper itself may also have a knockout function to remove the processed workpiece from the collet chuck.

In this method, the workpiece is inserted into the chuck from the front of the chuck either manually or through a pushing member with a handling function, but the pushing pressure of the pushing member is a compression spring that functions as a knockout operation. If the pressure is small compared to the pressure or if the stroke of the pushing member is insufficient, the joint between the workpiece and the stopper reference surface may not be accurately positioned. Furthermore, if the tolerance between the inner diameter of the spindle and the fitting surface of the stopper is loose, play may occur in the stopper, causing the seating position relative to the workpiece reference surface to be tilted, which may cause displacement in the axial direction when the chuck is clamped. All of these are factors that cause variations in the longitudinal dimensions of the workpiece. In the latter case, since the mounting portion of the stopper is exposed to the outside from the slotted portion of the collet, the collet is a special collet in which the slotted portion itself forms a split portion that is wider than usual. Similarly, the stopper attachment part must be machined into a complicated shape, and when the workpiece is frequently changed, there is an economical cost problem in preparing a considerable number of stoppers. The explanation so far has raised the problems shown in the conventional examples regarding the function of the stopper. Next, in explaining the collet chuck of the present invention, I will briefly touch on the selection stroke of chucking. Although it is indirectly connected to and controlled by a mechanical means such as a chuck cylinder or cam via a drawbar, the stroke of the chuck cylinder or the height of the cam drop is determined at the stage of selecting the chuck specifications corresponding to the machine capacity. Many things remain unchanged. However, if the cylinder stroke can be adjusted within a range that allows for collet deflection force, chucking can be achieved to a certain extent without replacing the butt and collet if there is a slight difference in workpiece diameter or shape. It is hoped that this will be possible. Conventionally, this has been done by changing the collet or butt setup.

The present invention aims to eliminate the above-mentioned two drawbacks in a collet chuck equipped with a stopper. Hereinafter, the present invention will be explained based on practical drawings.

(Example) 1 is the chuck body (hereinafter referred to as the main body), and the main shaft 2
is mounted on top. Reference numeral 3 denotes a collet chuck, and an outer diameter tapered portion 4 on the outer circumference engages with an inner diameter tapered portion 5 on the inner circumference of the main body 1. The collet chuck 3 has slotted portions 7 equally divided on the circumference in the longitudinal direction of the thick side portion of the body portion 6 which communicates with the outer diameter tapered portion 4 of the collet chuck 3. A gripping action is taken on the workpiece through the self-springing properties brought about by the function of , and the mutual wedge action of the tapered parts 4 and 5 . collet chaff 3
At the rear of the body 6, the outside diameter of the body 9 that communicates with the connection part 8 with the drawbar or the piston rod of the chuck cylinder that connects the collet chuck 3 is the body part 9 on the side that communicates with the outside diameter tapered part 4. 6, a stepped side wall portion 10 of the barrel portion 6 that communicates with the body portion 9 on the connecting portion 8 side of the collet chuck 3 and the outer diameter tapered portion 4 is provided with a circumferential portion of the stepped side wall portion 10 in the axial direction. Through-holes 11 are provided which are equally divided at the top and pass through. Reference numeral 12 denotes a stopper installed in the collet chuck 3 concentrically with the center of the collet chuck 3, and one end surface of the stopper 12 is a reference surface having a surface angle with respect to the axis of the chuck. Reference numeral 13 denotes a spacer that is located behind the body 6 of the collet chuck 3 and is inserted between the stopper 12 and the body side wall la adjacent to the step side wall IO, and is inserted through the through hole 11. A bolt 15 is inserted into the provided screw hole 14 to close the stopper 12.
are fixed on the main body l while maintaining a concentric phase. Different thicknesses of the spacer 13 can be selected within the range of the stroke of the chuck cylinder, which will be described later. Therefore, even if the stroke of the chuck cylinder is constant, spacers I3 with different thicknesses
Since the stroke of the chuck cylinder can be arbitrarily selected by replacing the collet chuck 3, the gripping movement range of the chuck can be changed within the allowable range of the deflection force of the collet chuck 3 without replacing the collet or butt. That is, the stopper 12 corresponding to both ends of the step side wall IO and the step side wall 10 abut against both ends of the main body side wall 1a, so that the axial stroke of the collet chuck 3 changes in relative position regardless of the stroke of the chuck cylinder. Adjustment is possible, and the adjustment of this stroke is determined by selecting the thickness of the spacer 13. I6 is connected to the connecting portion 8 of the collet chuck 3 by a drawbar that moves relatively in the axial direction through the link action of a chuck cylinder, cam, or lever that is a driving source mounted on the rear part of the main shaft 2. An air suita port 12a is provided on the central axis of the stopper 12, communicating with the drawbar 16 and opening to the front of the collet chuck 3, to prevent foreign matter from entering the collet chuck 3.

From the above, the shape of the stopper attached to the collet chuck of the present invention is simple, and it has a complex structure in which the spacer retains the function of coaxial phase alignment with the collet chuck and serves as a joint with the main shaft of the stopper. has an element,
Moreover, the stopper can be easily replaced.

Furthermore, the axial stroke of the collet chuck can be adjusted without being regulated by the stroke of the chuck cylinder due to the combination of the stopper and the spacer.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the collet chuck of the present invention. 3 Collet chuck 12 Stopper 13...Spacer

Claims (1)

[Claims] A body part 9 having an outer diameter smaller than the outer diameter of the body part 6 on the side communicating with the outer diameter tapered part 4 of the collet chuck 3 and communicating with the connecting part 8 side communicating with the drive source of the collet chuck 3;
A through hole 11 is provided in the stepped side wall portion 10 of the body portion 6 that communicates with the outer diameter tapered portion 4 and is equally divided on the circumference in the axial direction of the stepped side wall portion 10, and a core of the collet chuck. A stopper 12 is mounted concentrically in the collet chuck 3, and a through hole 11 is interposed between the chuck body side wall 1a adjacent to the stepped side wall 10 and the stopper 12.
A spacer 13 is inserted through the spacer 13, and a bolt 15 is inserted through a screw hole 14 provided in the axial direction of the spacer 13 to fix the stopper 12 on the chuck body 1 while maintaining a concentric phase.
A collet chuck consisting of