JPH10337664A - Tail stock of cylindrical grinding machine for small workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To centrally support a small workpiece of low toughness at a proper load as well as to prevent stick slip by supporting a tailstock spindle on the head end part of which a movable center to centrally support the small workpiece is installed and on the rear end part of which an elastic member is installed on a hydrostatic bearing free to move in the axial direction. SOLUTION: A movable center 33 centrally supports a ferrule W by pressing it with a proper load by elastic springing force of a spring 34. A tailstock spindle 31 is supported on a hydrostatic bearing 32, and accordingly, stick slip is avoided even when sliding frictional force at the time of moving the tailstock spindle 31 becomes small and a tailstock load of the tailstock spindle 31 is small. Consequently, it is possible to prevent excessive impact fore against the ferrule W at the time of inserting the movable center 33 and a fixed center 21 into a fiber inserting hole (h) of the ferrule W and to prevent a chip and crack or generation of abrasion even when it is the ferrule W of low toughness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tailstock of a cylindrical grinding machine for grinding the outer periphery of a small tough work such as a ferrule used as an optical fiber connector part.

[0002]

2. Description of the Related Art In recent years, with the advent of multimedia,
There is a growing demand for ferrules, which are main connector parts for optical fibers.

The ferrule is formed, for example, from a zirconia ceramic material, has a fiber insertion hole formed in the ferrule in the axial direction, and inserts and holds an optical fiber in the fiber insertion hole.

Conventionally, as a tail stock of a cylindrical grinder for a small workpiece such as a ferrule of this type for grinding the outer periphery of a small tough workpiece, a tailstock having a structure as shown in FIG. 2 is used. Proposed.

The tailstock 10 shown in FIG.
A tailstock 12 is inserted into the housing 1, and the tailstock 12 is a rolling bearing 1 such as a ball bearing disposed in a housing 11.
3 is supported movably in the axial direction.

A movable center 1 is provided at the tip of the tailstock shaft 12.
4 and the tail end of the tailstock shaft 12 and the spring fixing seat 1
A spring 16 is interposed between the tailstock 5 and the tailstock 5 to bias the tailstock shaft 12 in one direction. Further, one end of an operating rod 17 is fixed to the rear end of the tailstock shaft 12, and the other end of the operating rod 17 is fixed to a hydraulic cylinder 18 that reciprocates in the axial direction of the tailstock shaft 12. Spring 16
Against the resilience of

When the outer periphery of the ferrule W is ground using the tailstock 10, first, a ferrule (small workpiece) W is placed between the fixed center 21 and the movable center 14.
Is supplied. Next, the operating rod 1 is moved by the hydraulic cylinder 18.
7 is actuated to release the drag on the spring 16. As a result, the tailstock shaft 12 is moved to the ferrule W by the resilience of the spring 16, and the tips of the movable center 14 and the fixed center 21 are inserted into the fiber insertion holes h of the ferrule W.
The ferrule W is supported at the center by the movable center 33 and the fixed sensor 21.

Then, the outer periphery of the ferrule W is
The ferrule W is rotated by sandwiching the roller 22 and the grindstone 23 and rotating the roller 22. Further, the grindstone 23 is rotated in the same direction as the ferrule W, and the outer periphery of the ferrule W is ground.

[0009]

By the way, in the tailstock of the cylindrical grinding machine for micro-workpieces as proposed above, the tailstock shaft 12 is supported by the rolling bearing 13 and the rolling friction force or the sliding friction force is large. When the tailstock load of the tailstock shaft 12 is small, so-called stick slip occurs in which the tailstock shaft 12 moves intermittently. For this reason, when the ferrule W is supported at the center, the followability of the tail shaft 12 with respect to the ferrule W is poor, and an excessive impact force is intermittently applied to the ferrule W having low toughness. There is a problem that cracks or wear occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent stick slip by providing a smooth movement of the tailstock shaft and toughness. It is an object of the present invention to provide a tail stock of a cylindrical grinding machine for a small workpiece capable of supporting a small workpiece with a moderate load at the center.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0012]

In order to achieve the above object,
The tailstock of the cylindrical grinding machine for micro-workpieces of the present invention has a tailstock having a movable center for supporting the center of the micro-workpiece at the front end and an elastic member mounted at the rear end, and a hydrostatic bearing. And is supported so as to be movable in the axial direction.

The tailstock of the cylindrical grinder for micro-workpieces according to the present invention is provided with a movable center for supporting the center of the micro-workpiece at the front end and an elastic member mounted at the rear end. However, it is characterized in that it is supported movably in the axial direction by a hydrostatic bearing into which the grinding fluid for the micro-workpiece has been introduced.

Further, the tailstock of the cylindrical grinder for micro-workpieces according to the present invention has a tailstock having a movable center for supporting the center of the micro-workpiece mounted at the front end and an elastic member mounted at the rear end. However, it is characterized in that it is supported movably in the axial direction by a hydrostatic bearing into which water or air is introduced.

Therefore, according to the present invention, since the tailstock is supported by the hydrostatic bearing, the sliding frictional force is reduced,
Even if the tailstock load of the tailstock is small, the tailstock can be moved smoothly.

Further, since the hydrostatic bearing uses a grinding fluid for a small workpiece, even if the grinding fluid for the hydrostatic bearing and the grinding fluid supplied to the micro-workpiece themselves are mixed, they have the same liquid quality. Therefore, there is no influence on the grinding efficiency of a small workpiece or the hydraulic pressure of the hydrostatic bearing.

Also, when water or air is used for the hydrostatic bearing, there is no effect on the grinding efficiency of the minute workpiece or the hydraulic or pneumatic pressure of the hydrostatic bearing.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic sectional view of a tailstock of a cylindrical grinding machine for a small workpiece according to an embodiment of the present invention.

In the tailstock 30 of the cylindrical grinding machine for small workpieces shown in FIG. 1, the tailstock shaft 31 has a ferrule (a small workpiece).
It is inserted through the shaft hole 32a of the hydrostatic bearing 32 into which the grinding fluid of W is introduced, and is supported so as to be movable in the axial direction.

A movable center 33 for supporting the ferrule W at the center is attached to the tip of the tailstock shaft 31. A spring 34 (elastic member) is interposed between the rear end of the tailstock shaft 31 and the spring fixing seat 35, and the tailstock shaft 31 is
4 biased in one direction. In addition, tailstock 3
The rear end of 1 is connected to a hydraulic cylinder 37 that reciprocates in the axial direction of the tailstock shaft 31 via an operating rod 36, and the hydraulic cylinder 37 resists the elastic force of the spring 34.

A plurality of injection ports 38a, 38b, 38c for the pressurized grinding fluid of the ferrule W are formed in the outer periphery of the hydrostatic bearing 32, and these injection ports 38a, 38b, 38 are provided.
c is communicated with the injection paths 39a, 39b, 39c so that the grinding fluid is injected into the shaft hole 32a from the injection ports 38a, 38b, 38c.

Since the tailstock of the cylindrical grinding machine for a small workpiece is configured as described above, when grinding the outer periphery of the ferrule W, first, the pressurized grinding fluid is supplied with the injection port 38a,
38b, 38c, the tailstock shaft 3
1 floats on the surface of the grinding fluid.

Next, the fixed center 21 and the movable center 3
When the ferrule W is supplied between the actuator 3 and the hydraulic cylinder 37, the operating rod 36 is operated by the hydraulic cylinder 37, and the drag on the spring 34 is released. Thereby, the tailstock shaft 31 is moved to the ferrule W by the resilient force of the spring 34, and the tips of the movable center 33 and the fixed center 21 are
At both ends of the fiber insertion hole h. This allows
Ferrule W is movable center 33 and fixed center 2
1 is center supported.

Thereafter, the outer periphery of the ferrule W is
The ferrule W is rotated by sandwiching the roller 22 and the grindstone 23 and rotating the roller 22. Further, the grindstone 23 is rotated in the same direction as the ferrule W, and the outer periphery of the ferrule W is ground.

In this case, the movable center 33 presses the ferrule W with an appropriate load by the elastic force of the spring 34, thereby supporting the center of the ferrule W without hindering the rotation of the ferrule W during grinding.

As described above, in this embodiment, since the tailstock shaft 31 is supported by the hydrostatic bearing 32, the tailstock shaft 3
The sliding friction force at the time of the movement of No. 1 is reduced, and stick slip is avoided even if the tailstock load of the tailstock shaft 31 is small. Therefore, when the movable center 33 and the fixed center 21 are inserted into the fiber insertion hole h of the ferrule W, an excessive impact force on the ferrule W can be prevented, and even the ferrule W having low toughness may be chipped, cracked or worn. Can be prevented from occurring.

Further, since the grinding fluid for the ferrule W is used for the hydrostatic bearing 32, even if the grinding fluid for the hydrostatic bearing 32 and the grinding fluid supplied to the ferrule W itself are mixed, they are the same. Therefore, there is no influence on the grinding efficiency of the ferrule W and the hydraulic pressure of the hydrostatic bearing 32. Therefore, the grinding and the center support of the ferrule W can always be stably performed.

Since the grinding fluid for the hydrostatic bearing 32 and the grinding fluid supplied to the ferrule W itself may be mixed, the leakage of the grinding fluid in the hydrostatic bearing 32 is prevented. Since there is no need to apply a seal such as a Teflon coating seal or an air seal to the seal 32, it is effective for cost reduction.

As described above, the tailstock of the cylindrical grinding machine for a small workpiece according to the embodiment of the present invention has been described in detail.
It is not limited to the tailstock of the cylindrical grinding machine for micro-workpieces described in the above embodiment, and various designs may be made without departing from the spirit of the invention described in the claims of the invention. It can be changed.

For example, in the embodiment of the present invention, the ferrule W grinding fluid is used for the hydrostatic bearing 32, but the same effect can be expected by applying water or air instead.

[0032]

As described above, according to the present invention, since the tailstock is supported by the hydrostatic bearing into which the grinding fluid, water or air for the minute workpiece is introduced, the sliding friction force is reduced. Even when the tailstock load of the tailstock shaft is small, stick slip of the tailstock shaft can be avoided. Therefore, it is possible to prevent an excessive impact force on a small workpiece, and to prevent the occurrence of chipping, cracking or wear even in a small workpiece having low toughness.

Further, since the hydrostatic bearing uses a grinding fluid for a small workpiece, even if the grinding fluid for the hydrostatic bearing and the grinding fluid supplied to the micro-workpiece themselves are mixed, they have the same liquid quality. As a result, there is no effect on the grinding efficiency of a small workpiece or the hydraulic pressure of the hydrostatic bearing.

Further, when water or air is used for the hydrostatic bearing, it does not affect the grinding efficiency of the minute workpiece or the hydraulic or pneumatic pressure of the hydrostatic bearing.

Therefore, the grinding operation and the center support of the minute workpiece can always be stably performed.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a tailstock of a cylindrical grinding machine for a small workpiece according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a tailstock of a conventional cylindrical grinding machine for small workpieces.

DESCRIPTION OF SYMBOLS 21 Fixed center 22 Roller 23 Grinding stone 30 Tailstock 31 Tailstock shaft 32 Static pressure bearing 32a Shaft hole 33 Movable center 34 Spring 35 Spring fixing seat 36 Working rod 37 Hydraulic cylinder 38a, 38b, 38c Inlet 39a , 39b, 39c Injection path W Ferrule h Fiber insertion hole

Claims (3)

[Claims] 1. A tailstock having a movable center for supporting a micro work center at a front end thereof and an elastic member mounted at a rear end thereof is supported by a hydrostatic bearing so as to be movable in an axial direction. A tailstock for cylindrical grinding machines for small workpieces. 2. A hydrostatic bearing in which a movable center for supporting a center of a micro-workpiece is mounted at a front end thereof, and a tailstock having an elastic member mounted at a rear end thereof is provided with a grinding fluid for the micro-workpiece. A tailstock for a cylindrical grinding machine for a small workpiece, which is supported so as to be movable in the axial direction by means of a shaft. 3. A tailstock having a movable center for supporting a micro work center at a front end thereof and an elastic member mounted on a rear end thereof is axially moved by a hydrostatic bearing into which water or air is introduced. A tailstock for a cylindrical grinding machine for a small workpiece, which is movably supported.