JPS62224506A - Hydraulic center clip - Google Patents

Abstract

PURPOSE:To enable the automatic mounting of a workpiece between both centers by providing a cylinder for free rotation along the external surface of a center at the main spindle side and feeding oil from an external cylinder so fitted as to be freely rotatable along the external surface of the aforementioned cylinder for opening and closing a concentric collet via a piston. CONSTITUTION:A center sleeve 20 is tapered and inserted in the bore of a machine tool spindle, and a center 9 screwed thereto is properly aligned with the center of a collet 8 and a bearing 18. Working oil fed from the oil feed hole 25 of an external cylinder 1 enters between a piston 21 and a cylinder 15 via a connection hole 27, thereby pressing the collet 8 forward for the closing thereof and working oil between the piston 21 and a cylinder cover 6 is made to return from a connection hole 26 via a drain hole 28. Therefore, when a workpiece 9 is held between the center 9 and a tail stock center and a dog 23 is turned with a round rod implanted in the dog plate of the machine tool, the cylinder 15 is turned and the workpiece is turned via the piston 21 and the collet 8.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for handling a workpiece at the same time as the main axis of a machine tool when the workpiece is sandwiched between two centers in operations such as turning and grinding. It relates to grip means for rotating.

[Conventional technology]

Conventionally, in operations such as turning and grinding, when processing a workpiece by holding it between both centers, for example, in the case of a grinder, the workpiece rotates at the same rotation speed as the main shaft, so the
As shown in a) and (b), a turner 51 is attached near one end of the workpiece 52, and both centers of the workpiece 52 are connected to the spindle side center 56 of the spindle head 51 and the dead center 57 of the tailstock 58. A round bar 59 protruding from the turning plate 53 is engaged with the turning ring 53 and rotated, and the grinding wheel 55 is pressed against the workpiece 52 while rotating to perform grinding. In order to perform this installation work easily, as shown in FIG.
The metal fitting 63, which is biased in the direction of the arrow by the spring 65, is attached, the projection 62 and the metal fitting 63 are held together to widen the space for clamping the workpiece 52, the workpiece 52 is inserted, and the hand is released. The workpiece 52 is grasped in one movement by the rod-shaped metal fitting 63 having a tightening means at the tip, and the round bar 59 attached to the turning plate 53 loosens the turner 61 to which the workpiece 52 is attached. There is also a complete rotating device that rotates in the direction of arrow C instead. There is also a method of chucking using a hydraulic or chamber pressure type three-way chuck.

(Problems to be Solved by the Invention) The conventional rotary screw described above is unsuitable for mass-produced workpieces because it takes time to loosen and tighten the bolts when attaching the workpiece. However, the improved rotary ring shown in FIG. 6 also has the disadvantage that the workpiece cannot be set on or removed from the machine tool using an autoloader, robot, or the like. Furthermore, hydraulic and pneumatic three-way chucks have the disadvantage that accurate centering cannot be performed.

(Means for Solving the Problems) The hydraulic center grip of the present invention includes a substantially cylindrical outer cylinder part that does not rotate, and which has first and second oil inlets and a drain hole, and this outer cylinder part. A communication hole is installed inside the piston via a plurality of bearings and supplies hydraulic oil supplied from the first and second oil inlets to the front or rear space of the large diameter part of the piston, and the main shaft of the machine tool. a cylinder body having means for rotating with the rotation of the cylinder; a cylinder lid that is engaged with the inner surface of the cylinder body and limits the stroke of the piston;
A piston that slides back and forth between the stepped part on the inner diameter of the rear part of the cylinder body and the cylinder lid by hydraulic oil that is selectively supplied from the first and second oil inlets, the rear end of the cylinder body, and the machine tool. The thrust bearing is placed between the center sleeve fastened to the axis of the main shaft of the cylinder, and is equipped with a spherical centering means that automatically centers the cylinder body. a collet that tightens or loosens one end of the workpiece by contacting or separating from a tapered surface provided on the cylinder; and a stopper attached to the front end of the cylinder lid that prevents the collet from moving toward the workpiece. , with the center fastened to the center sleeve.

[For production]

Therefore, when hydraulic oil is supplied from the first oil inlet,
The hydraulic oil is press-fitted into the space between the surface side of the large diameter part of the piston and the cylinder lid, and the oil in the space between the rear side of the large diameter part of the piston and the stepped part of the rear inner diameter of the cylinder body is injected into the space between the surface side of the large diameter part of the piston and the cylinder lid. The collet exits from the oil inlet, the piston retreats, and the collet loosens, making it possible to easily insert both center holes of the workpiece between the spindle side center and the center of the tailstock. Next, when the supply direction of the operating shaft is switched and hydraulic oil is supplied from the second oil inlet, hydraulic oil is filled into the space between the rear side of the large diameter part of the piston and the stepped part on the rear inner diameter of the cylinder body. The oil in the space between the front side of the large diameter part of the piston and the cylinder lid exits from the first oil inlet, causing the piston to move forward, and the tapered surface of the inner diameter of the piston creates a collet with multiple slits in the axial direction. will be tightened. In addition, in this case, the automatic centering means of the thrust bearing provided between the rear end of the cylinder body and the center sleeve ensures accurate centering, and the workpiece is centered between the center of the hydraulic center grip and the tailstock. It is gripped between the centers.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the hydraulic center grip of the present invention, FIG. 2 is a layout diagram showing the hydraulic center grip installed on a cylindrical grinding machine, and FIGS. ) and (b) are the respective turning wheels (A-A in Figure 2).
FIG. 3 is a diagram showing a cross section) and a shape of a collet.

The outer cylinder part 1 of the hydraulic center grip of this embodiment has a first oil inlet 24, a second oil inlet 25, and a drain hole 28.
A cylinder body 15 is rotatably fitted inside through two bearings 3, and the cylinder body 15 has communication ports that communicate with the first oil inlet 24 and the second oil inlet 25, respectively. 26 and 27 are provided. A large diameter portion 21 of a piston 21 is provided on the rear inner diameter of the cylinder body 15.
A stepped portion 15a is provided to form an operating space between the large diameter of the cylinder body 15, and a cylinder lid 6 that limits the movement stroke of the large diameter 21a of the piston 21 toward the 6T side is provided at the front part of the inner diameter. The front cover 5 is screwed onto the outer cylinder l.
It is screwed to with a plurality of screws 2. Furthermore, an outer rear cover 14 and an inner rear cover 16 are each attached to the rear side of the cylinder body 15 with a plurality of screws 2. The two bearings 3 arranged at the front and back inside the cylinder body 15 are fixed from the outside by screws 3a, and oil seals are installed between the front cover 5 and the outer rear cover 14 on the front and rear sides of the bearings 3, respectively. 4 is arranged to seal against leakage of hydraulic oil. The outer diameter of the piston 21 is such that the central part slides back and forth on the large diameter part of the cylinder body 15, and the rear part of the bait slides on the cylinder lid 6 and the small diameter part +5c of the stepped part +5a of the cylinder body 15, respectively. The space between the cylinder lid 6 and the cylinder body 15, between the large diameter portion of the piston 21 and the large diameter portion of the cylinder body 15, the small diameter portions at the front and rear of the piston 21, the small diameter portion of the cylinder body 15, and the cylinder lid. O-rings 12 and 13 are disposed at each sliding portion between the inner diameters of 6, respectively.

A taper 21a for tightening the collet 8 is formed on the inner diameter of the front side of the piston 21. cylinder lid 6
A stopper 7 that prevents the collet 8 from protruding forward from the outer cylinder 1 is screwed onto the inner diameter of the stopper 7.
is screwed together with the cylinder lid 6. Cylinder body 1
At the rear of the grinder 5, there is a turning plate 40 that rotates together with the main shaft of the grinder.
The cylinder body 15 is driven by a round rod 39 inserted into the cylinder body 15. A rotary ring 23 is attached by a tightening bolt 22. (See FIG. 3) A center sleeve 20 is tapered and fitted into the inner diameter (not shown) of the main shaft of the grinding machine, and is tightened to the rear end of the spindle head by a tightening bolt (not shown). Therefore, the center sleeve 20 does not rotate. Further, the center 9 is tapered fitted into the center sleeve 20 and tightened with a cap bolt 19. Between the rear end of the cylinder body 15 and the stepped portion 20a of the center sleeve 20 via the spacing piece 17, there is a spherical washer housing 11 tightened by a lock nut 10, and a spherical washer I1 having spherical seats on the front and rear sides of the double-row thrust bearing. 18 is installed.

Between the tapered part of the inner surface of the piston 2I and the stopper 7, there are slits at three locations each from the 0" side and the rear side, the cross-sectional and front views of which are shown in FIGS. 4(a) and 4(b). A collet 8 is provided.

The cylinder main body 15 is attached to the center sleeve 20 via a double-row thrust bearing 18 with a spherical seat, and the piston 21 and collet 8 built therein are attached so as to rotate together with the turning plate 40 by a turning metal 23. ′ of the center grip body 1 as shown in FIG. 51 oil inlet 24, second oil inlet 25 and drain hole 28, pipes 29, 30 and 34 are connected to the hydraulic unit 3, respectively.
5. The hydraulic unit 35 includes a motor 3
A pump 32 that is driven by the pump 3 and supplies hydraulic oil is attached thereto, and includes an electromagnetic valve 31 that switches the supply of hydraulic oil to the first oil inlet 24 and the second oil inlet 25.

Next, the operation of the hydraulic center grip of this embodiment will be explained. Hydraulic unit 3 sucked up by pump 32 7
The hydraulic oil in the pipe 29 is switched by the solenoid valve 31.
Through the first oil inlet 24 of the outer cylinder 1 of the center grip
is supplied to This hydraulic oil enters the space between the large diameter portion of the piston 21 and the cylinder lid 6 through the communication hole 26 of the cylinder body 15, and presses the piston 21 backward. On the other hand, the oil between the piston 2I and the stepped portion of the cylinder body 15 is pressed by the movement of the piston 21, and the communication hole 27,
It is returned to the hydraulic unit 35 via the piping 30. By moving the piston 21 to the rear piece, the Dever surface is separated from the outer surface of the collet 8, and the collet 8 is placed in a relaxed state. Here, when the solenoid valve 31 is switched to supply hydraulic oil to the second oil inlet 25 through the pipe 30, the hydraulic oil passes through the communication port 27 between the stepped portion of the cylinder body 15 and the large diameter portion of the piston 21. The piston 21 moves forward, and the oil between the large diameter part of the piston 15 and the cylinder lid 6 flows into the communication hole 26,
Hydraulic unit 3 via oil inlet 24 and piping 29
5, the inner tapered surface of the piston 21 tightens the collet 8. At this time, when the workpiece 37 is loaded between the center 9 and the center 36 of the Shinshindai, both center holes of the workpiece 37 tighten. is supported between the center 9 on the center grip side and the center 36 of the Shinshindai, and the end of the workpiece 37 on the center grip side is supported by the collet 8.
Chucked by. At this time, the center axis of the center sleeve 20 and the collet 8 to which the center 9 is fastened is
Accurate centering is achieved by a double row thrust bearing 18 with a spherical washer.

The oil that has lubricated each sliding part and the bearing 3 is returned to the hydraulic unit 35 from the drain hole 28 through the pipe 34.

[Effects of the Invention] As explained above, the present invention provides a cylinder that rotates at the same rotational speed as the main shaft of a machine tool, between a substantially cylindrical outer cylinder that does not rotate itself and a center sleeve to which a center is attached. A main body, a piston installed inside the cylinder body so as to slide in the backward direction by switching hydraulic pressure, a collet that tightens or loosens a workpiece when the piston slides back and forth, a cylinder body and A hydraulic center grip equipped with a thrust shaft equipped with a centering means that automatically centers the center sleeve and collet via a piston allows mass-produced workpieces to be mounted and removed using an autoloader, etc. each time the work is completed. This also has the effect of allowing accurate centering accuracy.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the hydraulic center grip of the present invention, FIG. 2 is a configuration diagram showing the hydraulic center grip installed on a cylindrical grinding machine, and FIG. 3 is the same as that of FIG. A-A sectional view, FIG. 4(a). (b) is a BB sectional view and front view of the collet, and Fig. 5 (a)
), (b) is an installation diagram of a conventional rotary wheel, a diagram showing a state in which the rotary rotor is attached to a cylindrical grinder, and FIG. 6 is an installation diagram of an improved rotary rotor. 1...Outer cylinder part, 2...Flat screw, 3...
Bearing, 3a...Bearing retaining screw, 4...Oil seal,
5...Front cover, 6...Cylinder lid,
7... Stopper, 8... Collet, 9...
...Center, 10-...Lock nut, 1
]...Spherical washer housing, +5...Cylinder body, 15a---Stepped part of cylinder body, (5b-...Large diameter part of cylinder body, 15cm...Small diameter part of cylinder body,! 6-・・Inner rear cover, l 7−・・
Spacing piece, 18--Double row thrust bearing with spherical washer, 19
---Cap bolt, 20--Center sleeve, 20a''-Stepped part of center sleeve, 21--Piston, 21 a-Taper part of piston, 22--Tightening bolt, 23--Turn Fri. 2 (--First oil inlet, 25--Second oil inlet,
26, 27-...Communication hole, 28...Drain hole.

Claims (1)

[Scope of Claims] A substantially cylindrical outer cylinder part that does not rotate itself and has first and second oil inlets and a drain hole, and a plurality of bearings installed inside the outer cylinder part, First,
A cylinder body equipped with a communication hole for supplying hydraulic oil supplied from a second oil inlet to a space on the front side or the rear side of the large diameter portion of the piston, and a means for rotating together with the main shaft of the machine tool; A cylinder lid that is attached to the inner surface and limits the stroke of the piston, and hydraulic oil that is selectively supplied from the first and second oil inlets between the stepped part of the rear inner diameter of the cylinder body and the cylinder lid. A spherical centering device that automatically centers the cylinder body is arranged between a piston that slides in the front-rear direction, the rear end of the cylinder body, and a center sleeve fastened to the axis of the main shaft of the machine tool. a thrust bearing provided with means; a collet that tightens or loosens one end of a workpiece by coming into contact with or separating from a tapered surface provided inside the piston as the piston moves in the front-rear direction; and the collet. A hydraulic center grip, comprising: a stopper attached to the front end of the cylinder lid, and a center fastened to the center sleeve, for preventing the cylinder lid from moving toward the workpiece.