JP3292202B2 - Chuck unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck unit for holding a workpiece such as a workpiece or a tool in a rotary machine tool.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional chuck unit has a hollow sleeve 1 having a face plate fastened to a front end thereof.
00, a draw bar 101 slidably disposed in the sleeve 100 in the axial direction, a master jaw 102 sliding in the radial direction on the face plate as the draw bar 101 moves in the axial direction, and the draw bar 101 is driven. Rotary cylinder 1
And a rotary valve 104 for supplying hydraulic pressure to the rotary cylinder 103. The rotating cylinder 103 is disposed at the rear end of the sleeve 100 and includes a piston 103a connected to the draw bar 101 and a cylinder housing 103b connected to the sleeve 100. The piston 103a is moved by receiving the supply of hydraulic pressure. The drawbar 101 is moved forward or backward in the axial direction. The master jaw 102 slides on the face plate in the radial direction along with the movement of the draw bar 101, whereby the work is attached and detached via the top jaw 105 attached to the master jaw 102.

[0003]

However, the chuck unit described above has a rotary cylinder 103 and a rotary valve 104 for driving the draw bar 101 in the axial direction.
Is arranged at the rear end of the sleeve 100, so that the overall length of the chuck unit is increased. In addition, the load on the spindle unit (rotating shaft unit) increases due to the vibration caused by the weight increase and the deterioration of the dynamic balance by the rotating cylinder 103, so that the rotation accuracy during high-speed rotation is reduced. Further, at the time of high-speed rotation, the rotary valve 104
In this case, there is a possibility that the axial dimension of the spindle portion may change due to the heat generated by the agitation of the oil in the above, and therefore, it is not possible to set the rotation speed limit high. Also, the rotary valve 10
The operation of No. 4 could not follow the high-speed rotation, and the non-stop chuck could not be performed at the time of high-speed rotation. The present invention has been made based on the above circumstances, and an object of the present invention is to provide a small-sized chuck unit that can rotate at a high speed.

[0004]

According to the present invention, in order to achieve the above object, according to the first aspect, a cylindrical rotary sleeve rotatably held and a coaxial type rotatable inside the rotary sleeve are provided .
One rotatably arranged which with a torsion bar which can store torsional force, the said rotary sleeve torsion
The chuck member moves in the radial direction according to the rotational phase difference with the bar.
A chuck mechanism that detaches a workpiece or a tool by being displaced, and a torsion bar that is driven to rotate in synchronization with the rotation of the rotating sleeve, and when both are rotating.
And a synchronous phase adjusting mechanism capable of changing the rotation phase of the above.

According to a second aspect of the present invention, a cylindrical rotary sleeve rotatably held, a torsion bar disposed coaxially within the rotary sleeve and capable of storing a torsional force, A chuck mechanism to which rotation and torsion forces are transmitted to detach and attach a workpiece, a tool, and the like, and a synchronous mechanism that rotationally drives the torsion bar in synchronization with the rotation of the rotary sleeve and changes its rotational phase. A phase adjusting mechanism, a commutator that rotates in synchronization with the rotating sleeve, and a brush that rotates in synchronization with the torsion bar; and a rotational phase amount between the rotating sleeve and the torsion bar, and an electrical phase between the brushes. And a rotational phase amount detecting means for detecting based on the ON / OFF signal of the conduction.

[0006]

The chuck unit of the present invention having the above-described structure is connected to the rotating sleeve and the torsion via the synchronous phase adjusting mechanism.
If a rotational phase difference is provided between the
The chuck member moves in the radial direction according to the difference.
Then, the work and the tool are detached. Claim 2
Includes a rotating phase amount detecting means having a commutator that rotates in synchronization with the rotating sleeve and a brush that rotates in synchronization with the torsion bar. This rotation phase amount detection means turns on / off electrical conduction between the brushes when a rotation difference occurs between the rotation sleeve and the torsion bar. It detects the amount of rotational phase between the torsion bar and the torsion bar.

[0007]

Next, an embodiment of a chuck unit according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view on the front end side of the chuck unit, and FIG. 2 is a cross-sectional view on the rear end side of the chuck unit. The chuck unit according to the present embodiment includes a rotating sleeve 1 having a cylindrical shape, a torsion bar 2 disposed coaxially in a hollow portion of the rotating sleeve 1 and capable of storing a torsional force, a rotating sleeve 1 and a torsion bar.
Chuck that is displaced in the radial direction according to the rotational phase difference from
A member (a top jaw 15 described later) is provided.
A chuck mechanism 4 for attaching and detaching a work 3 (a workpiece, a tool, or the like) via a hook member, and a torsion bar 2 that is driven to rotate in synchronization with the rotation of the rotary sleeve 1, and both rotate.
Synchronous phase adjusting mechanism 5 that can change the rotation phase when the motor is in operation , and rotation phase amount detection means (described later) that detects the rotation phase amount between rotation sleeve 1 and torsion bar 2.
And so on.

The rotary sleeve 1 is rotatably held by a housing 7 via bearings 6 arranged on the outer peripheral portions at both ends. Tip side of the rotating sleeve 1 (left side in FIG. 1)
A scroll holder 9 is provided on the inner peripheral portion via a metal bearing 8.
Are held rotatably, and the rear end of the scroll holder 9 and the front end of the torsion bar 2 are spline-coupled. A disc-shaped face plate 10 is fastened to the tip end surface of the rotary sleeve 1 by a bolt (not shown). On the face plate 10, a master jaw 12 having a drive pin 11 is provided.
Is arranged. The master jaw 12 has three grooves (not shown) in which the drive pins 11 are formed in the face plate 10.
Are guided so as to be slidable on the face plate 10 in the radial direction.

[0009] Further, on the tip end surface of the scroll holder 9,
As shown in FIG. 3 (A view in FIG. 1), three cam grooves 13 inclined in the radial direction are formed, and the drive pins 11 of the master jaw 12 are fitted into the cam grooves 13. .
Accordingly, when a rotational phase occurs between the face plate 10 and the scroll holder 9, the drive pin 11 moves in the radial direction with the engagement with the cam groove 13, so that the master jaw 12 moves on the face plate 10 in the radial direction. Will slide. The drive pin 11 is fastened to the master jaw 12 by a bolt 14. On the tip side of the master jaw 12,
A top jaw 15 for grasping the work 3 (workpiece or the like) is fastened by bolts 16. The chuck mechanism 4 includes a face plate 10, a scroll holder 9, a master jaw 12, a top jaw 15, and the like.

The synchronous phase adjusting mechanism 5 includes a harmonic reducer 17, a timing pulley 18, and a timing pulley 1.
9, a drive motor 20, a chuck motor 21, a clutch unit 22, and the like. The harmonic reducer 17 includes a circular spline 17a, a flex spline 17b, and a wave generator 17c. The circular spline 17a is fastened to the rear end of the rotary sleeve 1 together with the timing pulley 18. The flex spline 17b forming the output shaft is fastened to the rear end of the torsion bar 2, and the wave generator 17c forming the input shaft is connected to the timing pulley 19 by bolts 23.
Is fastened to the shaft 24 fixed to the shaft.

The timing pulley 18 is engaged via a belt 25 with an output shaft 20a of the driving motor 20 and a pulley 26 fixed to the rotor of the clutch unit 22. The timing pulley 19 is connected via a belt 27. ,
The clutch unit 22 is engaged with a pulley 28 fixed to a stator portion of the clutch unit 22. The pulley 28 is engaged via a belt 30 with a pulley 29 fixed to an output shaft 21 a of the chuck motor 21. The timing pulley 19 is connected to the timing pulley 1 via a bearing 31.
8 and is rotatably supported by the clutch unit 22.
Can be directly connected to the timing pulley 18 in the rotation direction.

The rear end face of the timing pulley 18
As shown in FIG. 2 (a BB view), the commutator 32
The pair of brushes 33 that come into contact with the commutator 32 are built in the timing pulley 19. A wiring 34 is provided at the center of the rear end of the timing pulley 19.
A signal coupler 35 (trademark) electrically connected to the brush 33 is attached, and the other signal coupler 36 facing the signal coupler 35 is provided on the rotation axis of the timing pulley 19. In addition,
The above-described rotation phase amount detecting means includes a commutator 32, a brush 33, and signal couplers 35 and 36.

Next, the operation of this embodiment will be described. By providing a rotational phase difference between the rotary sleeve 1 and the torsion bar 2 via the synchronous phase adjusting mechanism 5 and sliding the master jaw 12 on the face plate 10 in the radial direction (center direction), the top jaw 15 The work 3 is chucked via the. After the chucking, the rotation phase is further greatly changed, so that the torsion bar 2 is twisted, and the torsional force is transmitted as the chucking force. Since this chucking force is proportional to the amount of twist of the torsion bar 2, an arbitrary chucking force can be easily obtained.

The amount of rotational phase between the rotary sleeve 1 and the torsion bar 2 (the amount of torsion of the torsion bar 2) depends on the phase difference generated between the timing pulley 18 and the timing pulley 19, and the brush 33 slidingly contacts the commutator 32.
Since electric conduction is turned on and off between the signals, the on / off signal can be detected by transmitting the on / off signal to an external control unit (not shown) via the signal couplers 35 and 36. As described above, by detecting the amount of twist of the torsion bar 2 on the basis of the ON / OFF signal generated between the brushes 33, the rotating sleeve 1 rotates at a rotation speed (for example, 20,000 rpm) higher than the response of the encoder. Also, a difference (for example, 10 rpm) between the rotational speeds of the rotating sleeve 1 and the torsion bar 2 can be easily detected as an on / off pulse. For this reason, non-stop chucking at high speed rotation becomes possible.

Next, a second embodiment of the present invention will be described. FIG. 5 is a sectional view of a chuck unit employing a stationary collet chuck. Components having the same functions (or names) as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The chuck unit according to the present embodiment includes a bearing 6.
The torsion bar 2 and the draw bar 37 are attached to the shaft of the rotary sleeve 1 rotatably supported by the housing 7 via
And are arranged. The draw bar 37 is slidably held in the axial direction by the torsion bar 2, and is at the rear end side (right side in FIG. 5).
A non-rotating pin 38 is fixed to the groove 39 formed on the inner peripheral surface of the rotary sleeve 1 so as to be slidable in the axial direction. A screw is formed at the tip of the draw bar 37,
A top 40 is fastened to the screw. Rotating sleeve 1
A cylindrical holder 42 is fastened to a tip end surface of the holder 42 via a bolt 41, and a sleeve 43 is provided on an inner peripheral portion of the holder 42.
Are slidably held in the axial direction. A collet 44 for attaching and detaching a work is arranged inside the sleeve 43, and a tapered surface formed on the inner periphery on the distal end side of the sleeve 43 and a tapered surface formed on the outer periphery of the collet 44 are engaged with each other. ing. A screw is formed on the outer periphery of the tip of the holder 42, and the cap 45 is fastened. In addition,
On the right side of FIG. 5, the synchronous phase adjusting mechanism 5 shown in the first embodiment is provided. can do.

In the chuck unit having the above structure, the draw bar 37 moves in the axial direction by providing a rotational phase difference between the rotary sleeve 1 and the torsion bar 2. With the movement of the draw bar 37, the collet 44
The sliding contact of the tapered surface with the sleeve 43 causes the distal end of the collet 44 to be displaced in the radial direction, thereby enabling the work to be detached. As described above, since the draw bar 37 is driven in the axial direction via the torsion bar 2, the wedge-shaped chuck 4 shown in FIG.
6, or power chucks such as a crank type chuck, a compensating type chuck, a wedge-shaped three-jaw hollow chuck, a draw down chuck, and a power change chuck.

By using a servo motor for the drive motor 20 and the chuck motor 21, even if the clutch unit 22, the commutator 32, the brush 33, and the signal couplers 35 and 36 are omitted, the rotary sleeve 1 can be used.
, The synchronous rotation and the phase rotation of the torsion bar 2 can be performed. Further, by detecting the motor current of the servomotor, the torsional force of the torsion bar 2 can be controlled more precisely. Alternatively, it is possible to set a more precise twisting force by detecting the rotation of the servomotor with an encoder. Harmonic reducer 17 was abolished, and belt 25 and torsion bar 2
It is also possible to have a simple structure that directly connects

[0018]

The chuck unit according to the present invention has a structure in which a work is detached by rotation of a torsion bar, and a chucking force is obtained by a torsional force stored in the torsion bar. Therefore, the chucking force can be set arbitrarily. In addition, since a conventional rotary cylinder or rotary valve is not required, high-speed rotation is possible, and the overall length of the chuck unit is reduced, so that downsizing can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view on the tip side of a chuck unit.

FIG. 2 is a rear end side sectional view of a chuck unit.

FIG. 3 is a view as viewed from A in FIG. 1;

FIG. 4 is a BB view of FIG. 2;

FIG. 5 is a sectional view of a chuck unit according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a power chuck.

FIG. 7 is a schematic configuration diagram of a conventional chuck unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotating sleeve 2 torsion bar 3 work (workpiece or tool) 4 chuck mechanism 5 synchronous phase adjusting mechanism 32 commutator (rotational phase amount detecting means) 33 brush (rotating phase amount detecting means) 35 signal coupler (rotating phase amount detecting means) 36 signal coupler (rotational phase amount detection means)

Claims (2)

(57) [Claims] A) a cylindrical rotary sleeve rotatably held; b) a torsion bar coaxially and rotatably disposed in the rotary sleeve to store a torsional force; c) Rotational position between the rotating sleeve and the torsion bar
The chuck member is displaced in the radial direction according to the phase difference.
A chuck mechanism for attaching and detaching a workpiece, a tool, and the like; and d) rotating the torsion bar in synchronization with rotation of the rotating sleeve, and changing a rotation phase when both are rotating . A chuck unit equipped with a synchronous phase adjustment mechanism that can be used. A) a cylindrical rotary sleeve rotatably held; b) a torsion bar disposed coaxially within the rotary sleeve and capable of storing a torsional force; c) a torsion bar. And a chuck mechanism for transmitting and receiving the rotation and torsional force of the torsion bar, and d) for rotating and driving the torsion bar in synchronization with the rotation of the rotary sleeve and changing the rotation phase thereof. E) a commutator that rotates in synchronization with the rotating sleeve and a brush that rotates in synchronization with the torsion bar, and the amount of rotational phase between the rotating sleeve and the torsion bar is adjusted by the A chuck unit comprising: a rotation phase amount detection unit that detects based on an on / off signal of electrical conduction between the brushes.