JPH04146063A - Work-centering method and chuck device for cylindrical grinder - Google Patents

Abstract

PURPOSE:To remarkably shorten the time necessary for centering of an eccentric work only by moving a chuck body in an eccentric direction of the eccentric work and a a direction intersecting that direction at a right angle. CONSTITUTION:A chuck body 8 is mounted on a mounting surface of a planar plate 7 mounted on the tip end portion of a spindle 3 in such a manner as to be movable in two directions intersecting each other at a right angle and including an eccentric direction of a work W. Subsequently, a test work is chucked by a collet chuck 9 mounted to the chuck body 8. Centering of the work W is performed only by moving the chuck body 8 in a required direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a workpiece centering method and a chuck device in a cylindrical grinder in which an eccentric workpiece is mainly gripped and processed by a collet chuck.

[Conventional technology]

In cylindrical grinding machines, a chuck device using bevels has traditionally been used to grip and process eccentric workpieces, and is currently the mainstream.

This chuck device manufactures a V bevel that corresponds to the amount of eccentricity of an eccentric workpiece, fits this V bevel into a U-shaped recess provided in the chuck body, and fixes it with a bolt.
The eccentric workpiece placed on the bevel is clamped from above with a clamping tool, and in this state, by rotation of the spindle,
This is a device that grinds a workpiece by rotating the chuck body.

Even if the V bevel is machined according to the drawing dimensions, it is difficult to center the workpiece in reality, so adjustment spacers are inserted into the sides and bottom of the V bevel for centering. This spacer must be installed in advance.

Make the comb thicker than the required size, gradually thin it by hand polishing, insert it into the side and bottom of the V bevel, and repeat the centering operation for final centering. There is. In this way, even if the height of the center of the workpiece can be achieved by adjusting the thickness of the spacer through manual polishing, It is not possible to obtain comprehensive accuracy including the slope, etc.

Also, even if you insert the spacer made with cash as described above into the side or bottom of the V bevel and tighten the V bevel to the chuck body with a bolt, the bolt tightening torque is too high. Centering work for chuck devices using bevels is extremely troublesome work that requires considerable skill and perseverance, as the V bevel may tilt or the center of the workpiece may change due to changes in factory temperature. . For this reason, when machining accuracy in μ units is required, it is recommended to use a torque limiter to tighten the bolts or insert an additional thicker under the spacer to make delicate centering adjustments. In reality, the centering work performed in this way is
It usually takes one to one and a half days, and even for an expert, it takes half a day.

Furthermore, the fatal drawback of chuck devices that use bevels is that if there are variations in the outer diameter dimensions of the clamp part of the workpiece in the previous process, the height of the center of the workpiece will change due to this variation in dimensions. Therefore, after machining, the eccentricity of the workpiece becomes uneven, and when machining workpieces with different eccentricity, it becomes necessary to manufacture a new chuck device including the bevel. The cost would be enormous.

[Problem to be solved by the invention]

The present invention was made in view of the above-mentioned problems of chuck devices that use bevels. By using a collet chuck, it is possible to center a workpiece in a short time and with high precision. At the same time, the main objective is to make the eccentricity of the workpiece after processing constant regardless of variations in the outer diameter dimension of the workpiece in the previous process, and to perform highly accurate grinding processing.

[Means to solve the problem]

The chuck device according to the present invention has a chuck hole formed in the center, and a face plate attached to the tip of the spindle is attached to the face so as to be movable in two mutually orthogonal directions including the eccentric direction of the workpiece. a chuck body, a collet chuck inserted into the chuck hole of the chuck body, and a collet chuck that comes into contact with the outer peripheral surface of the chuck body to position the chuck body in two directions orthogonal to each other including the eccentric direction of the workpiece. The chuck body comprises a plurality of positioning means attached to the face plate for the purpose of fixing the chuck body to the face plate, and a fixing means for fixing the chuck body to the face plate.

[Action of the invention]

The test workpiece is gripped by a collet chuck attached to the chuck body, and the chuck body is moved in the eccentric direction of the workpiece and in two directions orthogonal to this, and the chuck body is positioned using a plurality of positioning means. The final centering of the workpiece is performed by repeating the centering operation.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

FIG. 1 is a front view of a chuck device according to the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a sectional view taken along line A--A in FIG. 1. In these figures, headstock 1
A spindle 3 is rotatably supported via a bearing 2 with its axis horizontal, and a flange 5 is attached to the front end of the spindle 3 via a fixing bolt 4, and a fixing bolt 6 is attached to the front surface of the flange 5. A ring-shaped face plate 7 is attached to the front surface of the face plate 7, and a chuck main body 8 is attached as will be described later.

The chuck body 8 is formed with a chuck hole 11 in which a tapered part and a straight part are connected for mounting the collet chuck 9 in the center thereof, and has a plurality of elongated chuck holes 11 extending along the eccentric direction X of the eccentric workpiece W to be gripped. bolt holes 12 are provided. The collet chuck 9 is inserted and attached to the chuck hole 11 of the chuck body 8, and the bolt hole 12
The chuck main body 8 is fixed to the face plate 7 by a plurality of fixing bolts 13 inserted into the chuck body 8.

There is a cavity 1 inside the flange 5, face plate 7, and chuck body 8, which are integrally connected by a fixed pole 6.13.
4 is formed, and a nut member 15 for connecting the collet chuck 9 and a drawbar 18, which will be described later, is disposed in the cavity 14. This NAND member 15 is the fifth
As shown in the perspective view in the figure, a fitting recess 15a that fits into a fitting protrusion 8a formed on the back side of the chuck body 8 is formed at the tip end, and a slider (to be described later) is formed at the rear end. 17 is provided with a narrow diameter portion 15b that is engaged with the elongated hole 17a, and a female screw portion 15c that is screwed into the straight portion of the collet chuck 9 is provided in the center portion. A notch 16 as shown in FIG. 6 is integrally attached to the back surface of the chuck body 8, and the notch 16 is inserted into a notch insertion hole 15d provided in the NAND member 15.

As shown in FIG. 7, a keyway 20 is formed in the rear end of the eccentric workpiece W, and when the eccentric workpiece W is inserted into the collet chuck 9 attached to the chuck body 8, the rear end surface becomes a notch 16. At the same time, the protrusion 16a of the notch 16 is inserted into the keyway 20 formed at the rear end, and the fixing position in the circumferential direction is determined. .

A slider 17 is slidably fitted onto the inner circumferential surface of the spindle 3, and this slider 17 is attached to the tip of a drawbar 18, and as shown in FIG. The narrow diameter portion 15b of the NAND member 15 is inserted into and engaged with the NAND member 15, so that the nut member 15 is movable relative to the slider 17 only in the eccentric direction X of the eccentric workpiece W.

A fitting convex portion 8 a provided on the back side of the chuck body 8 is fitted into a fitting recess 15 a provided at the tip of the nut member 15 , and a fitting convex portion 8 a provided on the back side of the chuck body 8 in the collet chuck 9 is fitted. The protruding part is the NAND member 15
The collet chuck 9 and the nut member 15 are designed so that their axes do not deviate from each other. When the drawbar 18 is pulled and the tensile force is transmitted to the collet chuck 9 via the slider 17 and the nut member 15, a part of the taper of the collet chuck 9 is reduced in diameter and the eccentric workpiece W is gripped.

Furthermore, positioning bolts 19a for positioning the chuck body 8 are provided at both end portions of the face plate 7 along the eccentric direction X of the eccentric workpiece W and at both end portions along the direction Y perpendicular thereto.

19b is installed. That is, positioning bolts 19a are attached to both end portions of the face plate 7 along the eccentric direction X of the eccentric workpiece W through dead stoppers 21, and the positioning bolts 19a are attached to both end portions of the face plate 7 along the eccentric direction X of the eccentric work W. Guide plates 22 are disposed at both end portions along the chuck body 8 to abut against both side surfaces of the chuck body 8, and positioning bolts 19b are screwed into the guide plates 22. This guide plate 22 is attached to the face plate 7 via fixing bolts 23.
Fixed.

Further, as shown in FIGS. 1 and 2, a proximity switch 24 is attached to the end face of the headstock 1, and
A dog 25 is attached to a predetermined position in the circumferential direction of the flange 5 that rotates together with the chuck body 8, and when the proximity switch 24 detects the dog 25, the chuck body 8 is always kept at a predetermined position (collet The eccentric workpiece W gripped by the chuck 9 is stopped at a position where the eccentric direction X of the workpiece W is directed upward or downward, thereby facilitating centering work.

Next, a method for centering the eccentric workpiece W using the above-mentioned chuck device will be explained.

Insert the test work W° into the collet chuck 9 attached to the chuck body 8 and bring it into contact with the notch 16, and
When the protrusion 16a of the notch 16 is inserted into the keyway 20 provided at the rear end of the test workpiece W', the chuck body 8
Next, the test workpiece W' is positioned in both the axial direction and the circumferential direction relative to the test workpiece W'. Next, a tensile force is applied to the collet chuck 9 by the draw bar 18 to grip the test workpiece W', and then the fixing bolt 13 is is loosened to release the fixation of the chuck main body 8 to the face plate 7, and at the same time, the positioning bolts 19a, 19b are slightly spaced apart from the outer peripheral surface of the chuck main body 8.

In this state, while slowly rotating the spindle 3 and visually checking the deflection of the eccentric part W'a of the test workpiece W', the test workpiece W' is struck by hitting the outer peripheral part 8b of the chuck body 8 with a wooden hammer. After roughly centering the eccentric part W'a, rotate the spindle 3 slowly in the same way and place the dial gauge on the eccentric part W'a of the test workpiece W° to check the direction of the eccentricity and its direction. While reading the amount, move the four positioning bolts 19a, 19b back and forth little by little to find the target center.

If the core of the test work W' comes out as described above,
When the chuck body 8 is fixed to the face plate 7 with the fixing bolts 13, and then the guide plates 22 arranged on both sides of the chuck body 8 are brought into contact with the chuck body 8 and fixed, all centering work is completed. do. In addition, in Fig. 1 and Fig. 3, CI and Ct respectively represent the eccentric workpiece W.
The axis of the eccentric part Wa and other parts is shown, and the axis of the eccentric part Wa coincides with the axis of the spindle 3 due to centering.

The reason why the collet chuck 9 can be used to center the eccentric workpiece W in this way is that even after the drawbar 18 applies a tensile force to the collet chuck 9 to grip the eccentric workpiece W, the collet chuck 9 can be centered. This is because the center and the axis of the spindle 3 maintain parallelism. What made this possible was the slider 1 on the inner peripheral surface of the spindle 3.
7 are slidably fitted together, and the nut member 15
By fitting the fitting convex part 8a of the chuck body 8 into the fitting concave part 15a of the collet chuck 9, the axes of both are aligned and do not shift, so that the direction of the tensile force acting on the collet chuck 9 is always aligned with the spindle 3. This is because it was designed to be parallel to the axis of the

In addition, when centering another eccentric workpiece with a different amount of eccentricity, the positioning of the workpiece in the direction Y perpendicular to the eccentric direction X has already been performed by the first centering operation described above. Centering can be performed only by fine adjustment using the positioning bolt 19a provided in the eccentric direction X of the workpiece. Therefore, the time required for the second and subsequent centering operations is halved.

The above-mentioned eccentric workpiece W has a keyway 20 provided at its rear end at a position in the same phase as the eccentric direction, and this keyway 20 is used to position the chuck body 8 in the circumferential direction. If there is no reference part for positioning the workpiece in the circumferential direction, as is generally done, a separate device is installed to determine the circumferential phase of the workpiece, and at the same time, the positioning of the chuck body when setting the workpiece is If a device W (a device that inserts a V-shaped slot into the side of the chuck body is often used) for determining the stopping position is provided, it is possible to center any eccentric workpiece.

In addition, in FIG. 1 and FIG. 3, 26 indicates a grinding wheel.

〔Effect of the invention〕

(1) Centering of an eccentric workpiece can be performed only by moving the chuck body in the eccentric direction of the eccentric workpiece and in a direction orthogonal thereto. As a result, compared to a conventional chuck device using a V bevel, the time required for centering a workpiece is significantly shorter, and at the same time, no special skill is required for centering.

In addition, in the second and subsequent centering operations, centering can be performed by moving the chuck body only in the eccentric direction of the workpiece, so that the time required for centering operations is further reduced.

(2) If a workpiece with the same loft has been machined for a long period of time and the center of the workpiece has shifted, the center of the workpiece can be immediately restored by just finely adjusting the positioning bolt. As a result, it is not necessary to stop the grinding operation for a long time to adjust the centering.

(3) By simply moving the chuck body and changing the fixing position using the positioning bolt, it is possible to freely perform from coaxial machining to eccentric axis machining.

(4) Since the workpiece is gripped by a collet chuck, even if the outer diameter of the gripping part varies in the previous process, it does not affect the eccentricity of the workpiece to be processed at all.

(5) In this way, setup changes due to changes in workpieces can be made in a short time by simply moving the chuck body, which is extremely effective in multi-product machining, and it is also possible to use separate tools such as spacers for centering. Because no body parts are used, high processing accuracy is maintained over a long period of time. For this reason, the present invention eliminates the numerous drawbacks of the conventional chuck device using bevels.

[Brief explanation of the drawing]

FIG. 1 is a front view of a chuck device according to the present invention, and FIG.
The figure is also a plan view, and Figure 3 is A-A in Figure 1.
&l+ sectional view, FIG. 4 is a sectional view taken along line B-B in FIG. 3, FIG. 5 is a perspective view of the nut member 15, FIG. 6 is a perspective view of the notch 16, and FIG. 7 is an eccentric workpiece. It is a perspective view of W. The explanations of the symbols of the main parts constituting the present invention are as follows. W: Eccentric workpiece Wa: Eccentric part of the eccentric workpiece Bolt (fixing means for the chuck body) 19a,
19b: Positioning bolt (positioning means for chuck body) Patent applicant Kondo Seisakusho Co., Ltd.

Claims (2)

[Claims] (1) The chuck body is movably mounted on the mounting surface of the face plate attached to the tip of the spindle in two directions orthogonal to each other, including the eccentric direction of the workpiece, and the test workpiece is held by the collet chuck attached to this chuck body. A method for centering a workpiece in a cylindrical grinder, characterized by centering the workpiece only by gripping it and moving the chuck body in a required direction. (2) a chuck body that has a chuck hole formed in its center and is movably mounted on the mounting surface of a face plate attached to the tip of the spindle in two mutually orthogonal directions, including the eccentric direction of the work; A collet chuck that is inserted into a chuck hole of a chuck body and attached to the chuck body; and a collet chuck that comes into contact with the outer peripheral surface of the chuck body and is attached to the face plate for positioning the chuck body in two directions orthogonal to each other including the eccentric direction of the workpiece. A chuck device for a cylindrical grinding machine, comprising: a plurality of attached positioning means; and a fixing means for fixing the chuck body to the face plate.