JPS6156846A - Main spindle construction - Google Patents

Abstract

PURPOSE:To eliminate the necessary for a power transmission mechanism and reduce weight, by providing a driving motor, for rotating a main spindle, being directly connected with the main spindle, in the case of a machine tool of machining center or the like. CONSTITUTION:A driving shaft 13 is connected between a main spindle 6 and a driving motor 15 through a connection part 13a forming a connection hole 13e. A reciprocating motion transmission means of a connection bracket 16 or the like is provided in a mount-removal means of a tool 21 in a condition that a part of the bracket is protruded outside a driving shaft 11 through the connection hole 13e. Further the driving shaft 13 provides in its peripheral part a reciprocating driving means of a piston 17 or the like movably drivably in the direction of an arrow head A, B further a reciprocating motion transmission means reciprocating and drivably. Accordingly, the reciprocating motion transmission means transmits driving force of the reciprocating driving means, provided in the peripheral part of the driving shaft 13, through the connection hole 13e to the mount-removal means of the tool provided inside a main spindle 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a spindle structure applied to a rotatable spindle for detachably holding a tool in a machine tool such as a machining center.

(b), Prior Art Conventionally, the rotatable main shaft of this plate has a tool attachment/detachment means such as a drawer for attaching/detaching the tool, and a driving means for the said attachment/detachment means such as a hydraulic cylinder, which move in the axial direction of the main shaft. They are arranged in series, and a drive motor for rotating the main shaft is installed on the side of the main shaft and independent of the main shaft.The WE drive motor and the main shaft are usually connected to a power transmission groove such as a gear train or belt was connected via.

(d) Means to solve problem 0 However, in this case, since a power transmission mechanism is interposed between the TJXiPiI motor and the spindle, the weight of the spindle head becomes heavy, and the entire spindle head becomes heavy. There were drawbacks such as a decrease in positioning accuracy when moving to a predetermined position and machining, and heat generated from the power transmission groove increased thermal displacement of the spindle, which adversely affected machining accuracy. .

As a countermeasure for this, a system in which the drive morph is directly connected to the main shaft may be considered, but if the tool attachment/detachment means, its drive means, and the drive shaft that transmits the rotational force from the drive motor to the main shaft are capable of good tool attachment/detachment operation, The question of what kind of structure to arrange it while keeping it tight remained an unresolved issue.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a spindle structure that allows a tool to be smoothly attached to and removed from the spindle, and also allows a drive motor to be directly connected to the spindle. It is something to do.

(d) Means for solving the first problem, that is, the present invention provides a drive shaft directly connected to a drive motor, and connects the main shaft and the drive shaft through a connection portion in which a connection hole is formed. At the same time, there is a method for attaching and detaching the tool.
The L motion transmission means is provided with a part thereof protruding outside the drive shaft through the connection hole, and is further provided on the outer periphery of the drive shaft. , and is configured so that the forward txgh transmission means can be driven back and forth) 1.
When attaching and detaching to h, drive the reciprocating drive means,
The reciprocating driving force is transmitted to the attachment/detachment means via the connection hole by the forward fJL motion transmission means to attach/detach the tool from the main spindle, and the yjA movement of the spindle transfers the rotation of the drive motor via the drive shaft and the connection part. It acts by transmitting it to the main shaft.

(f), Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the main shaft structure according to the present invention, FIG. 2 is a three-dimensional cross-sectional view showing the main parts of the main shaft structure according to the present invention, and FIG. 3 is a view taken in the direction of the ■ arrow in FIG. .

Machining center work 8! The spindle head 1 in the area is
As shown in FIG. 1, it has a frame 2 formed in a cylindrical shape, and a cylindrical main bearing 3 is fitted on the right side of the frame 20 in the figure. A cylindrical main shaft 6 is rotatably supported by the main bearing 3 via a plurality of bearings 5, and a tool holding portion 6 formed in a tapered shape is provided at the right end of the main shaft 6.
a is formed. A sleeve 7 is fitted on the left side of the tool holding portion 6a, and a drawbar 9 is provided on the sleeve 7 and the main shaft 6 so as to be movable in the direction of the main shaft axis, that is, in the directions of arrows A and B. . A piston portion 9a that slidingly engages with the main shaft 6 is formed at the left end of the drawbar 9.
A plurality of disc springs 10 are provided between the piston portion 9a and the sleeve 7.
The drawbar 9 is always biased in the direction of arrow A, and a collet 11 is provided at the right end of the drawbar 9 so as to be openable and closable in a radial direction with respect to the axis of the main shaft 6.

On the other hand, a ring nut 8 for holding the bearing 5 is screwed onto the outer periphery of the main shaft 6.
A connecting portion 13a of the drive shaft 13 is connected to the left side in the figure via a key 12 and a plurality of bolts 14. The drive shaft 13 extends leftward in FIG. 1 to form an output shaft 15a of the drive motor 15.
As shown in FIGS. 2 and 3, the drive shaft 13 includes a solid small-diameter solid shaft 13b and a solid shaft 13b.
It has a connection part 13a consisting of stepped shafts 13c and 13d with a hollow part 13f formed inside.The stepped shafts 13c and 13d have six main shaft centers. Connecting holes 13e elongated in the direction are provided at two locations at a pitch of 180° with respect to the main shaft axis, and the stepped shaft 13c,
13 d penetrating toward the spindle axis side (i.e., the hollow part 13
f and the outside of the connecting portion 13a).
Ru.

Further, as shown in FIGS. 2 and 3, a connecting bracket 16 is fixed to the piston portion 9a of the drawbar 9 by a bolt 18 through the hollow portion 13 of the stepped shafts 13c and 13d. The connection bracket 16 is provided with two arms 16a in a five-shape shape, with their tips protruding outward from the solid shaft 13b through the connection hole 13e.

Further, a space 13h is formed on the right side of the drive shaft 13 in FIG. 2 to prevent interference between the bolt 18 and the drive shaft 13. The piston portion 9& of -9 is in contact with the inner end surface 13 of the drive shaft due to the elasticity of the disc spring 10.

In addition, as shown in FIG. 1, on the outside of the solid shaft 13b,
A piston 17 is fitted and engaged so as to be movable in the directions of arrows A and B, and a cylinder block 19 in which a cylinder 19a is formed is attached to the frame 2 corresponding to the outer peripheral portion of the piston 17.
is provided with a piston 17 slidably fitted into the cylinder 19a. Note that the number 20 is a bearing that supports the drive shaft 13.

Since the spindle head 1 has the above configuration, the tool 21
When the tool holder 6a of the main shaft 6 is mounted, pressure oil is supplied to the cylinder 19a of the cylinder block 19 to move the piston 17 in the direction B along the drive shaft 13. Then, the tip 17a of the piston 17 and the connection bracket 16
When the arm 16a contacts and the piston 17 further moves in the direction B, the arm 16a slides in the connection hole 13 of the drive shaft 13 in the direction B, and as a result, the connection bracket 16 also moves in direction B.

When the connection bracket 16 moves in direction B, the drawbar
9 is released from the abutting and engaging relationship with the drive shaft inner end i[1113g, and the disk spring 1 moves inside the main shaft 6 via the piston portion 911.
It slides in the B direction against the elasticity of 0, and the
Engagement claw 11 of collet 11 provided at the right end of K9
a is opened outward with respect to the 6th axis of the main shaft. In this state, the tool 21 is pushed and set by inserting its taper shank portion 21a into the tool holding portion 6a, and then the screw 17 is moved back in the A direction via the cylinder 19a. Then, the tip 17a of the piston 17 and the arm 16a
The abutment and engagement relationship is released, the connection bracket 16 and the drawbar 9 move in the direction A due to the elasticity of the disc spring 1 (l), and the engaging claw 11a of the collet 11 also converges in the direction of the axis of the main shaft 6. The pull stand 21b of the tool 21 is grasped and engaged.

Even after the engaging claw 11a grips the pull stud 21b, the drawbar 9 moves in the input direction, so the tool 21 is pulled in the A direction via the pull stud 21b, and the tapered shank portion 21a is attached to the tool holding portion 6a. The tool 21 is securely held on the spindle 6 by contacting with a predetermined contact pressure. (In this state, the drawbar 9 and the inner end surface 13g of the drive shaft have a predetermined distance, so the elasticity of the disc spring 10 is
The tool 21 is attached to the main shaft 6 via the drawbar 9 and the collet 11.
(It works effectively to hold ζ.) When the tool 21 is held on the main shaft 6, the drive motor 1
5 is rotated. Then, the drive shaft 13 is rotationally driven via the output shaft 15a, and the main shaft 6 is further rotated via the connecting portion 13a1, key 12, etc. As a result, the second tool attached to the tool holder 6a also moves to the collet 11.
, rotates together with the drawbar 9, the connection bracket 16, etc.,
It becomes possible to perform predetermined processing.

When machining with the tool 21 is completed and the tool 21 is replaced, the cylinder 19a of the cylinder block 19 + ζ pressure oil is supplied to move the piston 17 in the direction B along the drive shaft 13. When the tip 17a and the arm 16n of the connection bracket 16 come into contact with each other and the piston 17 further moves in the direction B, the arm 16a moves in the connection hole 130 of the drive shaft 13 in eight directions.
As a result, the connection bracket 16 also moves in the B direction. When the connection bracket 16 moves in direction B, the drawbar 9 also slides in eight directions within the main shaft 6 through the piston portion 9& against the elasticity of the disc spring 1θ, and the collet provided at the right end of the drawbar 9 11 engaging claws 11
a is opened outward with respect to the main shaft G axis, and the tip of the drawbar 9 KM 9 b 1. s Contact the pull stud 21b of the tool 21 and push the tool 21 in the direction B,
The state in which the tool holding portion 6n and the tapered shank portion 21m are held in close contact is released.

Therefore, the tool 21 is removed from the tool holder 6a, and the tool 21 to be used next is attached to the tool holder 6n according to the procedure already described to continue machining.

(g) 4 Effects of the Invention As explained above, according to the present invention, the main shaft 6 and the drive shaft 13 directly connected to the drive motor 15 are connected via the connection part 13a in which the connection hole 13e is formed. At the same time, a reciprocal traction transmission means such as the connection bracket 16 is attached to the IQ attachment means of the workpiece Q21 such as the drawer 9 in the form of 1) a part of it protruding outside the drive shaft 13 through the connection hole 13e; established,
Furthermore, a reciprocating drive means such as a piston 17 is provided on the outer periphery of the drive shaft 13 so as to be movable and driveable in the directions of arrows A and B, that is, in the direction of the six axes of the main shaft, and to drive the reciprocating motion transmitting means back and forth. Therefore, the reciprocating motion transmission means can transmit the driving force of the reciprocating drive means provided outside the drive shaft 13 to the tool attachment/detachment means provided inside the main shaft 6 via the connection hole 13e. In addition to making it possible to smoothly attach and detach tools, it is also possible to provide the drive motor 15 directly on the axis of the main shaft 6, so that a gear train or a There is no need to provide a power transmission mechanism such as a belt (this eliminates the influence of thermal displacement of the main shaft 6 due to heat generated from such a power transmission mechanism, and enables high-precision machining. Since this is no longer necessary, 1.1 The weight of the main spindle head 1 can be reduced, and the positioning accuracy when moving and positioning the entire main spindle head 1 can be improved.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a -''AA embodiment of the main shaft 4 according to the present invention, Fig. 2 is a three-dimensional cross-sectional view showing the main part of the main shaft sliding structure according to the present invention, and Fig. 3 is an arrow marked with ■ in Fig. 2. This is a perspective view. 6...Main shaft 6a... Tool holding section 9... Attachment/detachment means (drawer) 13...
Drive shaft 13a... Connection portion 13e... Connection hole 15... Drive motor 16... Reciprocating motion transmission means (connection bracket) 17
...Reciprocating drive means (piston) 19a...
... Reciprocating drive means (cylinder) 21 ... Tool applicant Yamazaki Iron Works Co., Ltd. Agent Patent attorney Phase 1) Shinji (and one other person)

Claims (1)

[Scope of Claims] A main shaft provided with a tool holder capable of holding a tool is rotatably provided, and a tool attachment/detachment means is provided inside the main shaft so as to be movable in the axial direction of the main shaft with respect to the main shaft. In the main shaft structure, the drive shaft is provided directly connected to the drive motor, the main shaft and the drive shaft are connected through a connection portion having a connection hole, and the reciprocating motion transmission means is connected to the attachment/detachment means. A reciprocating drive means is provided on the outer periphery of the drive shaft, a part of which protrudes outside the drive shaft through a connection hole, and the reciprocating drive means is movably driven in the direction of the axis of the main shaft. Main shaft structure configured to allow reciprocating drive.