JP2001170802A - Main spindle of nc lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a main spindle of an NC lathe capable of holding various kinds of chucks such as an opening fixture, a closing fixture, a chuck of a work sandwich clamp type, etc., free to automatically connect and disconnect. SOLUTION: This main spindle 1 of an NC lathe is held inside of a main spindle base HS free to rotate through a plural number of bearings 2. A shaft center inside of the main spindle 1 is furnished with a draw bar 6 for work clamping to hold a plug 5 to clamp a work 3 by a chuck (opening fixture) 4 on its head end part free to connect and disconnect and a cylinder 7 for work clamping to advance and retreat in the axial direction by connecting a cylinder piston 8 to a rear end of the draw bar 6 for work clamping. Additionally, the main spindle 1 is furnished with a draw bar 9 for chuck clamping provided in a concentrical tubular state by externally surrounding the draw bar 6 for work clamping and to hold the chuck (opening fixture) 4 on its head end part free to connect and disconnect and a cylinder 10 for chuck clamping to advance and retreat in the axial direction by connecting its cylinder piston 11 to a rear end of the draw bar 9 for chuck clamping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main spindle of an NC lathe, and more particularly to an NC lathe in which various chucks such as an opening toy, a closing toy and a work sandwich clamp type chuck are automatically and detachably held at an end thereof. Regarding the main spindle of a possible NC lathe.

[0002]

2. Description of the Related Art At the center of a shaft, a work clamp drawbar for detachably holding a stopper for clamping a work with a chuck at a tip portion thereof, and connected to a rear end of the work clamp drawbar to be axially connected. Conventionally, in a spindle of an NC lathe provided with a work clamping cylinder that moves forward and backward, a chuck such as an opening toy, a closing toy or a sandwich clamp type chuck is mounted on a flange fixed by screwing to an end of the spindle. Were bolted to the rear flange.

[0003]

SUMMARY OF THE INVENTION
The types (shapes and dimensions) of workpieces clamped by the same chuck are limited. Therefore, every time the type (shape or size) of the work to be clamped changes, the type (type, shape or size) of the chuck held at the tip of the spindle must also be changed. As described above, a conventional NC in which a chuck such as an opening jaw, a closing jaw or a sandwich clamp type chuck is fastened to the flange fixed to the end of the main shaft by screwing the flange at the rear end by a bolt. When changing the type (method, shape, and size) of the chuck held at the tip of the main spindle of the lathe main spindle, it is necessary to manually perform the following operations, which takes time and labor. (1) Loosen and remove fastening bolts. (2) Removal of the chuck. (3) Installation of another chuck and centering of the spindle. (4) Installation and tightening of fastening bolts.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and automatically and detachably holds various chucks such as an opening toy, a closing toy, and a work sandwich clamp type chuck at an end thereof. The main task is to provide a spindle of an NC lathe capable of performing the above. It is a second object of the present invention to provide a spindle of an NC lathe which does not require manual centering of the chuck and the spindle when replacing the chuck.

[0005]

According to a first aspect of the present invention, which solves the above-mentioned first problem, a stopper for clamping a work with a chuck is detachably held at a tip end thereof around a shaft. And a work clamp cylinder connected to the rear end of the work clamp draw bar and moving back and forth in the axial direction.
A drawbar for chuck clamp, which is provided on the main shaft of a C lathe and is concentric with the work clamp drawbar so as to detachably hold the chuck at a tip end thereof; And a chuck clamp cylinder connected to a rear end of the chuck for axially moving back and forth.
This is the main axis of the lathe.

With the above-described structure, various chucks such as an opening jaw, a closing jaw, and a work sandwich clamp type chuck can be automatically and detachably held at the end of the spindle of the NC lathe.

According to a second aspect of the present invention which has solved the first and second problems, in the first aspect, a large-diameter tube portion at the tip of the chuck clamp drawbar located at the tip of the spindle is provided. Enclosing chuck base, a plurality of projections provided circumferentially on a front end surface of the chuck base, and a plurality of engagement holes provided circumferentially on a rear end surface of a rear flange portion of the chuck. Wherein the chuck and the engaging hole are engaged with each other to determine the position of the chuck and to prevent the chuck from rotating.

With the above-described structure, in addition to the operation of the first aspect, there is an effect that it is not necessary to manually center the chuck and the spindle when replacing the chuck.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially cutaway side view showing the overall schematic structure of an embodiment of the present invention, FIG. 2 is an enlarged side sectional view of a main part of the embodiment of the present invention, and FIG. FIG. 4 is a partial side sectional view for explaining an operation in the mode.

A spindle 1 of an NC lathe according to an embodiment of the present invention.
Is rotatably held inside the headstock HS via a plurality of bearings 2 as shown in FIG. At the center of the shaft inside the main spindle 1, a work clamp drawbar 6 for detachably holding a stopper 5 for clamping the work 3 with a chuck (in this example, an opening jaw) 4 at the tip thereof,
A work clamp cylinder 7 is connected to the rear end of the work clamp draw bar 6 and is connected to the cylinder piston 8 so as to advance and retreat in the axial direction.

Inside the main shaft 1, the work clamp draw bar 6 is provided so as to surround and concentric with the work clamp draw bar 6 so as to detachably hold the chuck (opening toy) 4 at the tip thereof. Main part of the main spindle 1 of the NC lathe, comprising: a draw bar 9 for chuck clamp; and a chuck clamp cylinder 10 having a cylinder piston 11 connected to a rear end of the draw bar 9 for chuck clamp to move forward and backward in the axial direction. Is configured.

Next, the structure of the plug 5 will be described.
As shown in FIG. 2, the stopper 5 has a frusto-conical stopper head 5.
t, a plug main body 5mb having the plug head 5t fixed to the tip thereof with bolts 5tb, and a pull stud 5p screwed to the rear end of the plug main body 5mb. The front end of the pull stud 5p is the plug body 5mb.
A front flange portion 5pf in contact with the rear end face, a central small diameter portion 5ps following the front flange portion 5pf, and a rear large diameter portion 5pb following the central small diameter portion 5ps. The front end of the rear large-diameter portion 5pb is connected to a front taper portion whose outer diameter gradually increases from the outer diameter of the small-diameter portion 5ps, a central same outer diameter portion following the front taper portion, and a central same outer diameter portion. The central tapered portion has an outer diameter gradually reduced from the outer diameter of the same outer diameter portion.

Next, the structures of the work clamp draw bar 6 and the work clamp cylinder 7 will be described. As shown in FIG. 1, the work clamp drawbar 6 has a work clamp drawbar front portion 6f and a work clamp whose front end is screwed to a male screw portion at the rear of the work clamp drawbar front portion 6f. Drawbar main body 6mb, and a cylinder rod 6cr connected to the male screw portion of the rear end of the work clamp drawbar main body by screwing and further extending rearward. The cylinder rod 6cr in the work clamp cylinder 7 includes: A cylinder piston 8 whose outer peripheral surface slidably contacts the inner peripheral surface of the work clamping cylinder 7 is formed.

The work clamp drawbar front part 6f
Has a large-diameter cylindrical portion 6fbp formed at the front end thereof, a central flange portion 6ff continuous with the rear end of the large-diameter cylindrical portion 6fbp, and a rear small-diameter continuous with the rear end of the central flange portion 6ff. The portion 6fb is formed to constitute a work clamp drawbar front portion 6f. The central small-diameter portion 5ps and the rear large-diameter portion 5pb of the pull stud 5p are interpolated from the front of the large-diameter cylindrical portion 6fbp. A plurality of through-holes 6fbh are radially formed in the front part of the large-diameter cylindrical portion 6fbp in the circumferential direction, and the outer diameter of each of the plurality of through-holes 6fbh is smaller than the inner diameter of these through-holes 6fbh. A slightly smaller steel ball 12 is accommodated so as to be displaceable in the radial direction.

Then, from the front end face of the flange portion 9ff following the rear end of the large-diameter cylindrical portion 9fbp at the front end of the chuck clamp drawbar front portion 9f described later, the large-diameter cylinder at the front end of the work clamp drawbar front portion 6f. A large-diameter hole 9ffh having a predetermined length is added to the outer diameter of the portion 6fbp by a dimension slightly larger than twice the difference between the outer diameter of the steel ball 12 and the wall thickness of the large-diameter cylindrical portion 6fbp. At the rear end of the large-diameter hole 9ffh, the large-diameter hole 9ffh
h through a tapered hole that gradually decreases from the diameter of h to an inner diameter slightly larger than the outer diameter of the large-diameter cylindrical portion 6fbp at the front end of the work clamp drawbar front portion 6f.
9sh, a small-diameter through-hole slightly larger than the outer diameter of bp
Is continuous.

Next, the structure of the chuck 4 will be described. The opening toy 4 has a front large-diameter portion 4fb in contact with the inner periphery of the cylindrical work 3 and a rear end of the front large-diameter portion 4fb, the front end surface of which is in contact with the rear end surface of the cylindrical work 3. A center flange portion 4mf that is in contact with, a central small diameter portion 4ms that follows the rear end of the central flange portion 4mf, and a rear flange portion 4bf that follows the rear end of the central small diameter portion 4ms
And a pull stud 4p to which the external thread portion is screwed and fixed to the internal thread portion on the inner periphery of the rear flange portion. A plurality of radial slits 4sl are provided in the circumferential direction from the front end of the front large-diameter portion 4fb to the middle of the central small-diameter portion 4ms, and are divided into a plurality of segments. The pull stud 4p includes a front flange portion 4pf having a front end contacting a rear end surface of the rear flange portion 4bf, a central small diameter portion 4ps following the front flange portion 4pf, and a rear large diameter portion 4pb following the central small diameter portion 4ps. And The front end of the rear large-diameter portion 4pb has a front taper portion whose outer diameter gradually increases from the outer diameter of the central small-diameter portion 4ps, and a central same outer diameter portion following the front taper portion.
The center has the same outer diameter portion and a rear taper portion whose outer diameter gradually decreases from the outer diameter of the center same outer diameter portion.

Next, the constructions of the chuck clamp draw bar 9 and the chuck clamp cylinder 10 will be described. The draw bar 9 for chuck clamping includes:
As shown in FIG. 1, a rear end portion of the plug main body 5mb, the pull stud 5p, and a work clamp drawbar front portion 6
f, a tubular draw bar front part 9f for chuck chuck surrounding the f.
The front end is connected to the male screw part at the rear by screwing,
It comprises a tubular chuck clamp drawbar main body 9mb surrounding the work clamp drawbar main body 6mb, and a cylinder rod 9cr connected to the male screw portion at the rear end of the chuck clamp drawbar main body 9 by screwing and further extending rearward. At the rear end of the cylinder rod 9cr in the chuck clamping cylinder 10, a cylinder piston 11 whose outer peripheral surface slidably abuts the inner peripheral surface of the chuck clamping cylinder 10 is formed.

Drawbar front part 9 for chuck clamp
f has a large-diameter cylindrical portion 9fbp formed at the front end thereof. A central flange portion 9ff is continuous with a rear end of the large-diameter cylindrical portion 9fbp, and a rear portion is continuously formed at a rear end of the central flange portion 9ff. A small-diameter portion 9fb is formed to constitute a chuck clamp drawbar front portion 9f. A central small-diameter portion 4ps and a rear large-diameter portion 4pb of the pull stud 4p are inserted from the front of the large-diameter cylindrical portion 9fbp. A plurality of through holes 9fbh are radially formed in the front part of the large-diameter cylindrical portion 9fbp in the circumferential direction, and the outer diameter of each of the plurality of through holes 9fbh is smaller than the inner diameter of these through holes 9fbh. A slightly smaller steel ball 13 is accommodated so as to be displaceable in the radial direction.

The inner peripheral surface of the front hollow portion 1fe of the flange 1f at the front end of the main shaft 1 shown in FIGS. 1 and 2 and the outer peripheral surface of the large-diameter cylindrical portion 9fbp at the front end of the chuck clamp drawbar front portion 9f. Small-diameter cylindrical portion 14 inserted between
bs, and a chuck (jatoy) base 1 comprising a front flange portion 14ff following the front end of the small-diameter cylindrical portion 14bs.
4 is fastened to the flange 1f by a bolt (not shown).
Fixed. From the front end surface of the front flange portion 14ff to the outside diameter of the large-diameter cylindrical portion 9fbp at the front end of the chuck clamp drawbar front portion 9f, the outer diameter of the steel ball 13 and the thickness of the large-diameter cylindrical portion 9fbp. 2 of the difference
Large-diameter hole 1 with an inner diameter that is slightly larger than double
4ffh is drilled at a predetermined depth.
At the rear end of h, through a tapered hole that gradually decreases from the diameter of the large-diameter hole 14ffh to an inner diameter slightly larger than the outer diameter of the large-diameter cylindrical portion 9fbp at the front end of the chuck clamp drawbar front portion 9f, Small diameter through holes 14sh having an inner diameter slightly larger than the outer diameter of the large diameter cylindrical portion 9fbp are continuous.

The front end face of the front flange portion 14ff of the chuck base 14 has a projection 14t projecting in parallel with the axis.
Are provided on the same circumference (for example, four), while the rear flange portion 4bf of the chuck (opening toy) 4 facing the front end face of the front flange portion 14ff of the chuck base 14 is provided with the plural The same number of the engagement holes 4bh as the projections are provided.

By operating the work clamp draw bar 6 and the chuck clamp draw bar 9 of the spindle 1 of the present embodiment configured as described above, the chuck (opening jaw) 4 is moved to the front end of the chuck clamp draw bar 9. When the stopper 5 is attached to and detached from the front end of the work clamp draw bar 6, the following procedure is performed.

A. Assembling and integrating the stopper 5 and the chuck (opening toy) 4 (1) As shown in FIG. 3, the pull stud 4p is opened at the back of the opening toy 4 and the front end face of the front flange portion 4pf of the pull stud 4p is opened in advance. Rear flange 4bf of yatoy 4
Screw it in until it touches the rear end face. or,
As shown in FIG. 3, a pull stud 5 is
p is screwed and fixed until the front end surface of the front flange portion 5pf of the pull stud 5p comes into contact with the rear end surface of the plug rear flange portion 5bf at the rear end of the plug main body 5mb. (2) As shown in FIG. 3, the plug head 5t is not fitted and bolted to the front end of the plug main body 5mb, and the bolt head 5t is not tightened.
The plug body 5mb to which the pull stud 5p is fixed in the section is inserted from the left side of the drawing into the open toy 4 to which the pull stud 4p is fixed. (3) As shown in FIG.
At the front end of b, the plug head 5t is externally fitted and fastened and fixed with bolts 5tb.

B. Attachment and fixation of the opening jaw 4 and the stopper 5 (1) A pressurized fluid is supplied to each of a space behind the cylinder piston 11 of the chuck clamping cylinder 10 and a space behind the cylinder piston 8 of the work clamping cylinder 7 to perform chucking. The draw bar 9 for clamping and the draw bar 6 for work clamp are advanced to the right in the drawing.
As a result, the front portion 9f of the chuck clamp drawbar is drawn.
9fbh at the front end of the large-diameter cylindrical portion 9fbp at the front end
The large-diameter through hole 1 at the front end of the yatoy base 14
The vehicle is advanced to a position corresponding to an axial position of 4ffh. The work clamp drawbar front part 6f
Through hole 6fbh at the front of the large diameter cylindrical portion 6fbp at the front end of the
Is advanced to a position corresponding to the axial position of the large-diameter through hole 9ffh of the chuck clamp drawbar front portion 9f. (2) In this state, the opening toy 4 and the stopper 5 are pushed to the left in the drawing. At this time, in advance, each of the plurality of projections 14t on the front end face of the front flange portion 14ff of the chuck base 14 and the plurality of engagement holes 4bh on the rear end face of the rear flange portion 4bf of the opening jaw 4 are formed. Are positioned so as to engage with each other. Then, the steel ball 13 is pushed up while being rotated by the rear large diameter portion 4pb of the pull stud 4p, moves over the rear large diameter portion 4pb, and moves to the position of the rear end portion of the central small diameter portion 4ps. Also, the steel ball 12
The pull stud 5p is pushed up while being rotated by the rear large diameter portion 5pb, and moves over the rear large diameter portion 5pb to the position of the rear end portion of the central small diameter portion 5ps. (3) In this state, the pressurized fluid is supplied to the space in front of the cylinder piston 11 of the chuck clamp cylinder 10 and the space in front of the cylinder piston 8 of the work clamping cylinder 7, respectively, and the draw bar 9 for the chuck clamp and the draw bar 6 for the work clamp are supplied. To the left of the drawing.
Then, the through hole 9fbh at the front of the large-diameter cylindrical portion 9fbp at the front end of the chuck clamp drawbar front 9f.
Retreats to a position corresponding to a position behind the axial position of the large-diameter through hole 14ffh at the front end of the chuck (jatoy) base 14. Further, the through hole 6fbh at the front of the large-diameter cylindrical portion 6fbp at the front end of the work clamp drawbar front 6f is located behind the axial position of the large-diameter through-hole 9ffh at the chuck clamp drawbar front 9f. To the position corresponding to the position. As a result, the outer peripheral surface of the steel ball 13 is
ffh contacts the inner peripheral surface of the small-diameter through hole 14sh following the rear end of the pull stud 4p, so that the steel ball 13 and the rear large-diameter portion of the pull stud 4p are engaged. 4 is connected and fixed to the front part 9f of the draw bar for chuck clamp. In addition, steel ball 12
Of the small-diameter through-hole 9sh following the rear end of the large-diameter through-hole 9ffh, cannot be displaced radially outward therefrom, and the rear large-diameter of the steel ball 12 and the pull stud 5p The parts are engaged, and the stopper 5 is connected and fixed to the work clamp drawbar front part 6f.

C. Removal of the opening toy 4 and the stopper 5 (1) A pressurized fluid is supplied to each of a space behind the cylinder piston 11 of the chuck clamping cylinder 10 and a space behind the cylinder piston 8 of the work clamping cylinder 7 to perform chuck clamping. The draw bar 9 and the work clamp draw bar 6 are advanced rightward in the drawing. Then, the through-hole 9fbh at the front end of the large-diameter cylindrical portion 9fbp at the front end of the chuck clamp drawbar front portion 9f is positioned at the axial position of the large-diameter through-hole 14ffh at the front end of the chuck (jatoy) base 14. Advance to the corresponding position. Also, a through hole 6fbh at the front of the large-diameter cylindrical portion 6fbp at the front end of the work clamp drawbar front 6f,
The chuck clamp drawbar front portion 9f is advanced to a position corresponding to the axial position of the large-diameter through hole 9ffh. (2) In this state, the opening door 4 and the stopper 5 are pulled rightward in the drawing. Then, the steel ball 13
Is pushed up while being rotated by the rear large diameter portion 4pb of the pull stud 4p, the engagement between the rear large diameter portion 4pb of the pull stud 4p and the steel ball 13 is released, and the opening jaw 4 is moved to the chuck clamp draw bar. The front part 9f becomes detachable. In addition, the steel ball 12 is connected to the rear large-diameter portion 5 of the pull stud 5p.
Pushed up while being rotated by the pb, the engagement between the rear large diameter portion 5pb of the pull stud 5p and the steel ball 12 is released, and the plug 5 becomes detachable from the work clamp drawbar front portion 6f.

Next, the opening toy 4 and the stopper 5 attached and fixed to the tip of the spindle 1 as described in the above section B.
A method of attaching and detaching the work 3 to the opening toy 4 using the following will be described below. D. Removal of Work 3 (1) In a state where the work 3 is opened and clamped by the jaws 4 as shown in FIGS. 1 and 2, a pressurized fluid is supplied to the space behind the cylinder piston 8 of the work clamp cylinder 7 to perform work clamp The drawbar 6 is advanced rightward in the drawing. Then, the stopper 5 moves forward in the right direction in the drawing, and since the opening jaw 4 remains at the original position, the diameter of the opening jaw 4 is reduced by elasticity. (2) In this state, the work 3 is pulled out to the right in the drawing.

E. Attachment of Work 3 (1) In the state described in the item (2) of D, the work 3 is externally fitted to the opening toy 4 whose diameter is reduced from the right side in the drawings of FIGS. (2) The pressurized fluid is supplied to the space in front of the cylinder piston 8 of the work clamping cylinder 7, and the work clamp drawbar 6 is retracted leftward in FIGS. 1 and 2. Then, the stopper 5 retreats to the left in the drawing, and since the opening stopper 4 remains at the original position, the diameter of the opening stopper 4 is expanded by the stopper 5. As a result, the outer periphery of the large-diameter cylindrical portion 4fb of the opening toy 4 is pressed against the inner peripheral surface of the work 3,
The work 3 is opened and clamped to the stop 4.

The operation of the embodiment of the present invention configured as described above is as follows. (1) The opening jaw 4 can be automatically and detachably held at the front end of the spindle 1 of the NC lathe. (2) The centering work between the opening toy 4 and the main shaft 1 by hand when replacing the opening toy 4 becomes unnecessary.

The configuration and operation of an embodiment of the present invention have been described above, but the present invention is not limited to this embodiment. For example, in the above-described embodiment, the opening jaw 4 has been described as an example of the chuck attached to and detached from the front end of the spindle 1. However, instead of this opening jaw 4, other chucks such as a closing jaw or a sandwich clamp type chuck may be used. It is also applicable to classes.

[0029]

The present invention has the following excellent effects. (1) According to the first aspect of the present invention, various chucks such as an open toy, a closed toy, and a work sandwich clamp type chuck can be automatically and detachably held at the end of the spindle of the NC lathe. Becomes (2) According to the second aspect of the present invention, in addition to the effect of the above item (1), there is no need for manual centering of the chuck and the spindle when replacing the chuck.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an overall schematic configuration of an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view of a main part of an embodiment of the present invention.

FIG. 3 is a partial side sectional view for explaining an operation in the embodiment of the present invention.

[Explanation of symbols]

 HS Headstock 1 Spindle 2 Bearing 3 Cylindrical work 4 Chuck (opening toy) 4bh Engagement hole 5 Plug 6 Work clamp drawbar 6f Work clamp drawbar front 6mb Work clamp drawbar body 6cr Cylinder rod 7 Work clamp cylinder 8 Cylinder piston 9 Drawbar for chuck clamp 9f Front part of drawbar for chuck clamp 9mb Drawbar body for chuck clamp 9cr Cylinder rod 10 Cylinder for chuck clamp 11 Cylinder piston 12 Steel ball 13 Steel ball 14 Chuck (jatoy) base 14t Projection

Claims (2)

[Claims] 1. A work clamp drawbar for detachably holding a stopper for clamping a work with a chuck at a front end thereof at an axis center, and a work clamp drawbar connected to a rear end of the work clamp drawbar for axial direction. A work clamp cylinder, which is provided with a work clamp cylinder for moving forward and backward, wherein the work clamp draw bar is provided so as to surround and surround the work clamp draw bar, and the chuck is detachably held at the tip end thereof. And a chuck clamp cylinder connected to the rear end of the chuck clamp draw bar for axially moving back and forth.
A spindle of an NC lathe characterized by having: 2. A chuck base surrounding a large-diameter pipe portion at a tip of the chuck clamp draw bar located at a tip of the spindle, a plurality of protrusions provided in a circumferential direction on a tip surface of the chuck base, A plurality of engagement holes with the projections provided in a circumferential direction on a rear end surface of a flange portion at a rear end of the chuck; and positioning of the chuck and rotation stop by engagement of the projections with the engagement holes. The main spindle of the NC lathe according to claim 1, wherein the main spindle is formed to perform the following.