JP2022149439A - Tail stock - Google Patents

Abstract

To provide a tail stock capable of measuring a workpiece length accurately.SOLUTION: A tail stock according to the present invention supports one end of a workpiece gripped by a main shaft of a machine tool. The tail stock includes: a cylinder 11 mounted to a tail stock body 10; a piston 12 fitted and inserted into the cylinder in a reciprocatable manner; piston rods 13A, 13B connected to the piston; and a center 14 connected to ends of the piston rods 13A, 13B for supporting the workpiece. A measurement gauge 16 and a detector 18 for reading scale of the measurement gauge 16 are mounted on shafts of the piston rods 13A, 13B. One of the measurement gauge 16 and the detector 18 reciprocates together with the piston rods 13A, 13B in an axial direction J of the piston rods 13A, 13B. The other of the measurement gauge 16 and the detector 18 is fixed to the tail stock body 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tailstock that supports one end of a workpiece gripped by a spindle of a machine tool.

The tailstock (tailstock), for example, as shown in FIG. 4, comprises a center (tailstock shaft) 140 that supports one end of the work, and a cylinder 110 that controls the movement of the center 140 in the direction of the main axis of the machine tool. ing. A piston rod 130 is connected to the piston 120 in the cylinder 110 , and a center 140 is connected to the end of the piston rod 130 . By moving the piston 120 in the direction of the spindle of the machine tool, the center 140 also moves in the direction of the spindle, and the center 140 presses one end of the workpiece, thereby supporting the workpiece.

Patent Literature 1 describes a detection mechanism for detecting the stop position of the center when a work is supported in the tailstock.

In the detection mechanism described in Patent Document 1, as shown in FIG. 4, a drive rod 161 is attached via bearings 190, 190 to the side surface of a base 150 to which a tailstock body 100 is fixed. The drive rod 161 is connected to the center 140 via the mounting plate 160 . A support stay 162 is connected to the drive rod 161 , and a detector 170 is fixed to the end of the support stay 162 .

The drive rod 161 moves in the axial direction integrally with the center 140, and interlocking with this, the detector 170 fixed to the drive rod 161 also moves in the axial direction. On the other hand, a scale 180 is installed along the movement direction of the center 140 on a table (not shown) on which the tailstock body 100 is placed. As a result, the detector 170 connected to the center 140 via the mounting plate 160, the drive rod 161, and the support stay 162 moves along the scale 180, and by reading the graduations of the scale with the detector 170, A stop position of the center 140 when the work is supported is detected.

JP-A-11-114703

When the center 140 strikes the work, a load moment is applied to the center 140 from the work. Therefore, as shown in FIG. 5, when the tailstock body 100 that supports the center 140 receives the load moment and bends, the axial direction J of the piston rod 130 and the center 140 (hereinafter simply referred to as "the axial direction of the piston rod 130 J”) may tilt with respect to the scale 180 placed on the table on which the tailstock body 100 is placed. Further, the amount of protrusion of the center 140 changes the rigidity of the center 140, so the amount of inclination of the piston rod 130 in the axial direction J also changes. The effects of such load moments are particularly susceptible when the tailstock body 100 is fixed to the table.

As shown in FIG. 5, when the piston rod 130 is tilted in the axial direction J, the drive rod 161 fixed to the center 140 via the mounting plate 160 is similarly tilted, and furthermore, the support to which the detector 170 is fixed is also tilted. The stay 162 is similarly inclined.

FIG. 6 is a diagram showing the difference between the case where the axial direction J of the piston rod 130 is tilted under the influence of the load moment and the case where it is not tilted. In FIG. 6, positions indicated by reference numerals 140, 162, and 170 indicate the positions of the center, support stay, and detector when the axial direction J of the piston rod 130 is tilted, and reference numerals 140', 162', and 170'. indicates the positions of the center, support stay, and detector when the piston rod 130 axial direction J is not tilted.

As shown in FIG. 6, when the axial direction J of the piston rod 130 is tilted, the support stay 162 to which the detector 170 is fixed is also tilted. The position of the detector 170' is shifted by a distance D from when the direction J is not tilted. Therefore, when the detector 170 measures the stop position of the center 140 when the center 140 strikes the workpiece, the measurement results differ depending on whether the axial direction J of the piston rod 130 is tilted or not. A problem arises.

As a result, the work length cannot be measured accurately, and the correctness of the work length cannot be accurately determined. In addition, since the amount of inclination of the piston rod 130 in the axial direction J varies depending on the amount of protrusion of the center 140, an error in measurement of the length of the work occurs for works of different lengths.

SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and its main object is to provide a tailstock that can accurately measure the length of a workpiece without being affected by the load moment.

A tailstock according to the present invention is a tailstock that supports one end of a workpiece gripped by a spindle of a machine tool. , a piston rod connected to the piston, and a center connected to the end of the piston rod for supporting a workpiece, a length measuring gauge and a detector reading the scale of the length measuring gauge on the axis of the piston rod is attached, one of the length measuring gauge and the detector reciprocates in the axial direction of the piston rod integrally with the piston rod, and the other of the length measuring gauge and the detector is fixed to the tailstock body. .

According to the present invention, it is possible to provide a tailstock that can accurately measure the length of a workpiece without being affected by load moment.

1 is a cross-sectional view schematically showing the configuration of a tailstock in one embodiment of the present invention; FIG. FIG. 10 is a diagram showing a state in which the axial direction of the piston rod is tilted by receiving a load moment from the work when the piston moves in the work direction and strikes the work at the center; FIG. 5 is a cross-sectional view schematically showing the configuration of a tailstock in a modified example of the present invention; FIG. 10 is a diagram showing the configuration of a conventional tailstock provided with a detection mechanism for detecting the stop position of the center; FIG. 5 is a diagram showing a state in which the axial direction of the piston rod is tilted with respect to the scale when a load moment is applied; FIG. 10 is a diagram showing the difference between the case where the axial direction of the piston rod is tilted under the influence of the load moment and the case where it is not tilted.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In addition, this invention is not limited to the following embodiment. In addition, appropriate modifications are possible without departing from the scope of the effects of the present invention.

FIG. 1 is a cross-sectional view schematically showing the configuration of the tailstock in one embodiment of the present invention. The tailstock in this embodiment supports one end of the workpiece gripped by the spindle of the machine tool, and is used in a state of being fixed with bolts 40 or the like to the table 30 on which the machine tool is placed.

As shown in FIG. 1, the tailstock in this embodiment has a tailstock body 10 and a cylinder 11. A piston 12 connected to a piston rod is inserted into the cylinder 11 so as to be reciprocally movable. there is

The piston rods in this embodiment are a front rod 13A connected to the work side of the piston 12 (right side in FIG. 1) and a rear rod 13B (both rods) connected to the side opposite to the work side (left side in FIG. 1). consists of Here, the cylinder 11 can use a pneumatic or hydraulic cylinder, for example.

A center 14 for supporting a work is connected to the end of the front rod 13A. At the end of the rear rod 13B, a length measuring gauge 16 that reciprocates integrally with the front and rear rods 13A, 13B is mounted on the axis J of the front and rear rods 13A, 13B. Here, the length measuring gauge 16 should have at least a length equal to or longer than the stroke length of the piston 12 .

A cover (fixed portion) 17 is attached to the tailstock body 10. On the side of the cover 17, a detector 18 for reading the scale of the length measuring gauge 16 is mounted on the axis J of the front and rear rods 13A and 13B. is fixed to

In this embodiment, the length measuring gauge 16 and detector 18 are arranged coaxially on the front and rear rods 13A, 13B. The length measuring gauge 16 moves in the axial direction J integrally with the front and rear rods 13A and 13B, while the detector 18 is fixed to the tailstock body 10 via the cover 17. As shown in FIG.

In FIG. 2, when the piston 12 moves in the work direction (right direction in FIG. 2) and hits the work at the center 14, the load moment is received from the work, and the front and rear rods 13A and 13B move in the axial direction J. is a diagram showing a tilted state. Since the tailstock is used with the base 15, which is part of the tailstock body 10, fixed to the table 30 on which the machine tool is placed, the structure is susceptible to the load moment from the workpiece. It's becoming

As shown in FIG. 2, the length gauge 16 and the detector 18 are arranged coaxially on the front and rear rods 13A, 13B, so the position of the detector 18 with respect to the length gauge 16 is the front and rear rods. There is no difference between when the axial direction J of 13A and 13B is tilted and when it is not tilted. Therefore, when the detector 18 measures the stop position of the center 14 when the center 14 strikes the workpiece, the measurement is performed when the axial direction J of the front and rear rods 13A and 13B is tilted and when it is not tilted. The results are no different. As a result, the workpiece length can be accurately measured without being affected by the load moment.

In this embodiment, the length measuring gauge 16 and the detector 18 are arranged coaxially with the front and rear rods 13A and 13B. As long as the position of the detector 18 with respect to the length measuring gauge 16 does not shift, the length measuring gauge 16 and the detector 18 do not necessarily have to be arranged on a straight line.

Further, in the present embodiment, the detector 18 is fixed to the cover 17 attached to the tailstock main body 10, but the fixing portion for fixing the detector 18 is not limited to this, and the tailstock main body 10 itself, or As long as it is a member attached to the tailstock body 10, it may be of any form.

(Modification)
FIG. 3 is a cross-sectional view schematically showing the configuration of the tailstock in the modification of the invention.

As shown in FIG. 3, in the tailstock of this modified example, a cylinder 11 is attached to a tailstock body 10, and a piston 12 connected to a piston rod 13 is inserted into the cylinder 11 so as to be reciprocally movable. ing. In this modification, the piston rod 13 is connected (single rod) only to the work side of the piston 12 (the right side in FIG. 3). A center 14 for supporting a work is connected to the end of the piston rod 13 .

The piston 12 and the piston rod 13 are formed with a groove 20 extending through the piston 12 and into the interior of the piston rod 13 on the axis J of the piston rod 13 . A length measuring gauge 16 is mounted on the piston rod 13 within the groove 20 .

A cover (fixed portion) 17 is attached to the cylinder 11 , and the cover 17 has a shaft portion 17 a inserted into the groove 20 . A through hole is formed in the shaft portion 17a so that the length measuring gauge 16 can reciprocate. The detector 18 is fixed to a portion of the shaft portion 17a located on the center 14 side. A hole is formed in the cover 17 for taking out the signal line from the detector 18 .

In this modification, the length measuring gauge 16 and the detector 18 are arranged coaxially with the piston rod 13 . The length measuring gauge 16 moves together with the piston rod 13 in the axial direction J, while the detector 18 is fixed to the tailstock body 10 via the cover 17 and the cylinder 11 .

Also in this modification, since the length measuring gauge 16 and the detector 18 are arranged coaxially with the piston rod 13, the position of the detector 18 with respect to the length measuring gauge 16 is such that the axial direction J of the piston rod 13 is tilted. There is no difference between the case of tilting and the case of not tilting. Therefore, when the detector 18 measures the stop position of the center 14 when the center 14 strikes the workpiece, the measurement results differ depending on whether the axial direction J of the piston rod 13 is tilted or not. no. As a result, the workpiece length can be accurately measured without being affected by the load moment.

In addition, in this modification, the piston rod 13 is connected only to the workpiece side of the piston 12 (single rod), so the length of the tailstock in the axial direction J is shortened compared to the double rods in the above embodiment. can do.

Although the present invention has been described in terms of preferred embodiments, such description is not intended to be limiting, and various modifications are of course possible. For example, in the above embodiment, the length measuring gauge 16 is attached to the end of the rear rod 13B. may be attached to the rear rod 13. In this case, the cover 17 may also be formed with a shaft portion to be inserted into the groove, and the detector 18 may be fixed to a portion of the shaft portion located on the center 14 side, as in the above modified example.

In the above embodiment, the length measuring gauge 16 is attached to the piston rod 13 so as to reciprocate integrally with the piston rod 13, and the detector 18 is attached to the cover (fixed portion) attached to the tailstock body 10. 17, the detector 18 is attached to the piston rod 13 so as to reciprocate integrally with the piston rod 13, and the length measuring gauge 16 is attached to the cover (fixed portion) attached to the tailstock body 10. 17 may be fixed. In this case, a groove longer than the stroke length of the piston 12 is formed in the piston rod 13, and the length measuring gauge 16 is inserted into this groove and fixed to the tailstock body 10. good.

10 Tailstock body
11 cylinder
12 Piston
13 Piston rod
13A forward rod
13B rear rod
14 center
16 length gauge
17 cover (fixed part)
17a shaft
18 detector
20 groove
30 tables

Claims (4)

A tailstock that supports one end of a workpiece gripped by a spindle of a machine tool,
a cylinder attached to the tailstock body;
a piston reciprocally inserted into the cylinder;
a piston rod connected to the piston;
a center connected to the end of the piston rod and supporting the work,
A length measuring gauge and a detector for reading the scale of the length measuring gauge are mounted on the shaft of the piston rod,
One of the length measuring gauge and the detector reciprocates integrally with the piston rod in the axial direction of the piston rod, and the other of the length measuring gauge and the detector is fixed to the tailstock body. Yes, tailstock. The length measuring gauge is attached to the piston rod,
2. The tailstock of claim 1, wherein the detector is secured to a fixture attached to the tailstock body. The piston rod comprises a front rod connected to the work side of the piston and a rear rod connected to the side opposite to the work side of the piston,
3. The tailstock of claim 2, wherein said length gauge is attached to the end of said rearward rod. the piston and the piston rod are formed with a groove extending through the piston and into the piston rod on the axis of the piston rod;
The length measuring gauge is attached to the piston rod in the groove,
The fixed part has a shaft part inserted into the groove,
The shaft portion is formed with a through hole through which the length measuring gauge can reciprocate,
3. The tailstock according to claim 2, wherein the detector is fixed to a portion of the shaft portion located on the center side.

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