JP2007007811A - Center - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a center which can be adjusted by a simple method and at low cost such that the axis of the center coincides with the axis of the main spindle for a driving side chuck, and can precisely machine a workpiece, such as a round rod, even with a machine tool, such as a grinding machine, having poor accuracy caused by the use for a long time. <P>SOLUTION: The center having a fitting portion to be fitted into a machine and a pressing tip end portion for pressing and supporting the workpiece comprises a center body portion having the fitting portion, a first center movable portion arranged so as to move with respect to the center body portion in one direction perpendicular to the axis of the center body portion, and a second center movable portion which is arranged so as to move with respect to the first center movable portion in the direction perpendicular to the axis of the center body portion and further perpendicular to the movable direction of the first center movable portion, and has the pressing tip end portion, wherein the first center movable portion and the second center movable portion can be fixed to the center body portion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a center for rotatably holding a workpiece such as a part in a machine tool such as a grinding machine.

Conventionally, there have been centers that have been used as a single unit or a structure in which a pressing tip that comes into contact with a workpiece such as a component is rotatable.
For any type, there is no problem as long as the accuracy of the machine tool to be machined is high, but if it is used for a long time, the axis of the main shaft of the drive side chuck and the axis of the center will be When the workpiece such as a round bar is cut and supported by the chuck and the center, the outer diameter is tapered and the expected machining accuracy cannot be obtained.

  Japanese Patent Application Laid-Open No. 2004-228561 receives a projection of light irradiated on the inner diameter of a workpiece from one side by a camera with a microscope installed on the other side, and corrects a deviation from the axial center of the image by an XY adjustment mechanism. Is disclosed. However, the XY adjustment mechanism used here is not only extremely complicated in construction, but is also built between the rotation mechanism and the center gripping mechanism. The alignment by the method is very expensive. Further, Patent Document 1 does not disclose a technique for incorporating a position adjusting function in the XY direction into the center itself as in the present application described later, and does not suggest anything.

  The present invention is intended to solve the above-mentioned problems of the prior art, and is adjusted by a simple method and at a low cost so that the axis of the center of the center of the spindle of the drive side chuck is aligned. It is possible to provide a center capable of processing a workpiece such as a round bar with high accuracy even in a machine tool such as a grinding machine that has become inaccurate after long-term use. .

  The center according to claim 1, wherein the center includes a mounting portion to a mechanical device and a pressing tip portion that presses and supports a workpiece. The center includes a center main body portion having the mounting portion, and the center main body portion. A center first movable part disposed so as to be movable in one direction perpendicular to the axial direction, and the center first movable part perpendicular to the axial direction relative to the center first movable part and to the center main body part And a center second movable part that is arranged so as to be movable in a direction perpendicular to the movable direction of the center and has the pressing tip part, the center first movable part and the center second movable part being It is configured to be fixed to the center main body.

  Since the present invention is configured as described above, when the outer periphery of the workpiece 2 is cut by driving a machine tool such as a grinding machine to cut the outer periphery of the workpiece, By loosening, the fixed state of the center first movable part and the center second movable part to the center main body part is released, the position of the center first movable part is adjusted with respect to the center main body part, and the center first movable part On the other hand, by adjusting the position of the center second movable part, the center axis of the drive side chuck is adjusted so as to coincide with the axis of the spindle. After that, a machine tool such as a grinding machine whose static accuracy has deteriorated after a long period of use by a simple method of fixing the center first movable part and the center second movable part to the center main body part again by a fixing tool. Even so, it is possible to achieve an excellent effect that a workpiece such as a round bar can be processed with high accuracy. In addition, it is possible to adjust the axis of a machine tool such as a grinding machine whose accuracy has deteriorated at a much lower cost than the adjustment of the axis by an XY adjustment method on the spindle side. Furthermore, by providing the center with an XY adjustment mechanism, if the taper portion of the center mounting portion has the same shape, the center can be diverted to other facilities. .

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a cutting image diagram of a machine tool using the center of the embodiment of the present invention, and FIG. 2 is an enlarged view of the center of the embodiment of the present invention.
FIG. 3 is a cutting image diagram of a machine tool using the center of the conventional example. As described in the section of “Background Art”, 1 ′ is a uniting of the pressing tip portion, the mounting portion, and the center main body. The center of the conventional example formed is shown. Since the reference numbers other than the center 1 ′ of the conventional example are the same as the reference numbers in FIG. 1 and FIG. 2 which are the descriptions of the embodiments of the present invention described below, detailed description will be omitted.

FIG. 1 shows an image of cutting of a machine tool using the center 1 of the embodiment of the present invention.
A main shaft portion 4 and a tailstock 5 are disposed on a table 6, and the center 1 of the present invention is attached to the tailstock 5 via an attachment portion 8 (see FIG. 2). A workpiece 2 such as a round bar is sandwiched between the chuck 3 attached to the center and the pressing tip 15 of the center 1 and processed by a machine tool such as a grinding machine (not shown).

  FIG. 2 shows an enlarged state of the center 1 of FIG. The center 1 includes a center main body part 7, a center first movable part 10, a center second movable part 13, and a fixture 17.

  The center main body 7 is integrally formed with a mounting portion 8 attached to a center receiving portion (not shown) of the tailstock 5 on one end side of the cylindrical main body portion, and the mounting portion 8 is tapered on the outer periphery thereof. A tapered portion is formed and extends in the axial direction. Further, a first convex portion 9 extending in one direction perpendicular to the axial direction is integrally formed on the other end side of the cylindrical main body portion.

  The center first movable portion 10 is configured to movably receive a first convex portion 9 disposed in the center main body portion 7 and extends in one direction perpendicular to the axial direction. The part 11 is integrally formed at one end thereof, and the second convex part 12 extending in a direction perpendicular to the axial direction and perpendicular to the first groove 11 is integrally formed at the other end. is doing.

  The center second movable portion 13 is configured to movably receive the second convex portion 12 disposed in the center first movable portion 10, and is perpendicular to the axial direction and with respect to the first groove-shaped portion 11. A second groove-like portion 14 extending in a perpendicular direction is integrally formed on one end side thereof, and a tapered portion having a tip convex portion that engages with a concave portion provided on the end surface of the workpiece on the other end side. A pressing tip 15 is integrally formed with a conical body portion 16.

  Further, the center main body portion 7, the center first movable portion 10, and the center second movable portion 13 are each cut with a screw corresponding to the number of the fixtures 17 for receiving the fixtures 17 made of bolts, for example. A plurality of through holes 18 are provided. When the center 1 is used, the center main body 7, the center first movable portion 10, and the center second movable portion 13 are firmly fixed by the fixture 17.

Next, an adjustment operation for correcting the misalignment of the center of the center 1 with respect to the axis of the main shaft of the drive side chuck 3 based on the above-described configuration and aligning both axes will be described.
First, the center main body part 7, the center first movable part 10 and the center second movable part 13 are firmly fixed by the fixture 17, and the mounting part 8 of the center main body part 7 is a tailstock of a machine tool such as a grinding machine. 5 to the center 1 receiving part (not shown).
Next, one end portion of the workpiece 2 is fixed by the chuck 3 of the main shaft portion 4, and the tip convex portion of the center 1 is placed in a recess (not shown) provided in the other end portion of the workpiece 2. The workpiece 2 is clamped by engaging and pressing.
Next, a machine tool such as a grinding machine (not shown) is driven to cut the outer periphery of the workpiece 2, and the state of the taper generated on the outer periphery of the processed workpiece is measured. Next, the fixing tool 17 is loosened, and the center first movable part 10 is adjusted with respect to the center main body part 7 and the center second movable part 13 is adjusted with respect to the center first movable part 10 so that the taper becomes zero. After that, the center body 7, the center first movable portion 10 and the center second movable portion 13 are firmly fixed by the fixture 17, and the grinding machine is driven again to cut the outer periphery of the workpiece 2. The condition of the taper on the outer periphery of the processed workpiece is measured. If a taper still outside the allowable range is recognized, the fixing member 17 is loosened and readjusted, and after the readjustment, the fixing member 17 is tightened, and the center main body portion 7, the center first movable portion 10 and the center second movable portion. 13 is firmly fixed, and further, the grinding machine is driven to cut the outer periphery of the workpiece 2, and the state of the taper of the outer periphery of the processed workpiece is measured. Thereafter, this operation is repeated until the taper reaches a value within the allowable range, thereby correcting the misalignment of the center of the center 1 with respect to the axis of the spindle of the drive side chuck 3 and completing the adjustment work for matching the two axes. Let

  Since the present invention is as described above, when the outer periphery of the workpiece 2 is cut by driving a machine tool such as a grinding machine, the fixing tool is loosened. The center first movable part 10 and the center second movable part 13 are released from the fixed state to the center main body part 7, the position of the center first movable part 10 is adjusted with respect to the center main body part 7, and the center first By adjusting the position of the center second movable portion 13 with respect to the one movable portion 10, adjustment is made so that the axis of the center 1 coincides with the axis of the main shaft of the drive side chuck 3. After that, by using a simple method of fixing the center first movable part and the center second movable part to the center main body part 7 again with a fixing tool, a machine such as a grinder that has been used for a long time and has deteriorated static accuracy. Even if it is a machine, the outstanding effect that it becomes possible to process workpieces, such as a round bar, with high precision can be produced. In addition, it is possible to adjust the axis of a machine tool such as a grinding machine whose accuracy has deteriorated at a much lower cost than the adjustment of the axis by an XY adjustment method on the spindle side. Furthermore, by providing the center with an XY adjustment mechanism, if the taper portion of the center mounting portion has the same shape, the center can be diverted to other facilities. .

It is a cutting image figure of the machine tool which uses the center of embodiment of this invention. It is an enlarged view of the center of the embodiment of the present invention. It is a cutting image figure of the machine tool using the center of a prior art example.

Explanation of symbols

1 Center (present invention)
1 'Center (conventional example)
2 Workpiece 3 Chuck 4 Main shaft 5 Tailstock 6 Table 7 Center body 8 Mounting portion 9 First convex portion 10 Center first movable portion 11 First groove portion 12 Second convex portion 13 Center second Movable part 14 Second groove-like part 15 Pressing tip part 16 Fixing tool

Claims (1)

  In a center having a mounting portion to a mechanical device and a pressing tip portion that presses and supports a workpiece, the center includes a center main body portion having the mounting portion and an axis perpendicular to the center main body portion. A center first movable portion disposed so as to be movable in one direction; and perpendicular to the axial direction of the center first movable portion and perpendicular to the movable direction of the center first movable portion relative to the center main body portion. A center second movable part that is arranged so as to be movable in the direction and has the pressing tip part, and the center first movable part and the center second movable part with respect to the center main body part. A center characterized in that it can be fixed.

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