JPH034323B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a spindle tool clamping device that can be applied to machining centers, boring machines, radial drilling machines, and the like.

BACKGROUND OF THE INVENTION For example, in a vertical machining center, when exchanging tools on the spindle and magazine pot using an automatic tool changer with a twin-arm tool changer arm, the clamping and unclamping operations of both tools must be performed in synchronization. Furthermore, it was necessary to temporarily stop the operation of the tool changing arm in order to obtain a switching point between clamping and unclamping operations and a switching confirmation signal.

Problems to be Solved by the Invention Temporarily stopping the tool change arm in this way wastes time when the race is to shorten the tool change time by even one second and reduce idle time. This is not desirable as it requires a lot of effort, so it has become a challenge to do this in continuous operation without stopping the exchange arm.

Means to Solve the Problem In the main spindle 1 which has a collet 2 for fitting a tool into the main spindle, a tool pulling rod 7, etc., a plurality of collets 2 are arranged at equiangular positions and are long in the axial direction of the main spindle 1. A piece 6 which inserts an auxiliary pulling rod 8 into the center of the spring collet 3 and the tool pulling rod 7 and causes the spring collet to act on the tip of the auxiliary pulling rod 8.
The spring 9 is used to urge the piece 6 in the backward direction, and the spring collet 3 has a spring action in its arm before it engages with the pull stud Tb on the front side of the central fulcrum to perform automatic tool change operation. The tool can be inserted and removed in a half-clamped state with the spring collet 3 acting as before.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. Spindle 1 is the taper shank Ta of tool holder T.
The ridges 2 at the tips of the main collect 2 and the spring collect 3 are inserted into the holes 1b that extend to the tapered holes 1a in which the
A trapezoidal inner circumferential groove 1c into which a and 3a fall, an arcuate inner circumferential groove 1d in which a ball portion 3b serving as a fulcrum of the spring collet 3 engages is cut, and a small diameter hole 1e is drilled to pass through the hole 1b. has been done. In this example, the main collet 2 is split into two in the axial direction from a cylindrical state so that two spring collects 3 can be inserted therein, and the cross-sectional shape of the main collet 2 is a known one. The inclined jaw 2b on the inside of the portion 2a can engage with the slope of the neck Tc of the pull stud Tb of the tool holder T, the jaw 2c at the base engages with the jaw 4a of the drawbar, and the tip of the jaw 2c engages with the jaw 4a of the drawbar. The jaw 2b is normally biased in the opening direction by the force of the U-shaped plate spring 5 which contacts the neck 4b of the collet 2 and serves as a rotational fulcrum and presses the outside of the base of the collet 2. The spring collet 3 is a rod in the axial direction of the main shaft 1, and is slightly bent into a dogleg shape at a ball portion 3b at the middle fulcrum.
The slanted jaw 3c on the inside of the tip ridge 3a can engage with the slope of the neck Tc of the pull stud Tb, and a long arm 3d is formed up to the ball 3b which serves as a fulcrum, and this part has a spring action. Cage, ball part 3
A collector opening/closing protrusion 3f is formed on the inner side of the tip of the arm 3e, which extends further back than the arm 3d and shorter than the arm 3d. The spring action is necessary so that the pull stud Tb engaged with the jaw 3c can be inserted and removed when the arm 3d is pressed against the inner wall of the hole 1b, and its force is large enough to hold the tool without falling. The drawbar 4 is slidably inserted into the hole 1b of the main shaft 1 following the neck portion 4b, and has an oval hole 4c through which a leaf spring 5 that acts on the main collet 2 in a direction perpendicular to the axis is inserted, and an oval hole 4c that is perpendicular to the oval hole 4c. A rectangular hole 4d through which a piece 6 that acts on the spring collet 3 (described later) is inserted, and a blind hole 4e opening rearward are bored, and the ball portion 3b of the spring collet 3 extends in the outer axial direction.
Two arcuate grooves 4f are cut at 180 degrees apart and are slidable in contact with the hollow tool pull-up rod 7 with no gap, and the hollow tool pulling rod 7 is moved axially by a known drive means (not shown) on the female thread at the rear end and inserted into the hole 1e. is screwed on. An auxiliary pulling rod 8 is inserted through the center of the tool pulling rod 7, and a piece 6 inserted into the square hole 4d of the drawbar 4 is screwed to the tip of the rod.The piece 6 is moved by a spring 9 inserted into the hole 4e. Always being pushed backwards. The piece 6 is a contact surface 6 with the working protrusion 3f of the spring collet 3.
a, 6a have a length that maintains the contact state when the drawbar 4 is moved to open and close the main collet 2, and when the auxiliary pulling rod 8 is advanced, the working protrusion 3f
An escape portion 6b is provided for freeing.

Function The tool pulling rod 7 in the spindle 1 is now in the forward position, the main collet 2 is in an open state with the peak 2a falling into the trapezoidal groove 1c, and the auxiliary pulling rod 8 is in the retracted position, with the piece 6 in the spring position. The spring collet 3 is placed in a closed state by abutting against the operating protrusion 3f of the collet 3. In this state, when the taper shank Ta of the tool holder T is inserted into the taper hole 1a of the spindle 1 by the tool changer, the head of the pull stud Tb comes into contact with the inner slope of the tip crest 3a of the spring collet 3, and the arm 3d When the pull stud Tb is bent and pushed open, the pull stud Tb enters and its neck Tc engages with the inclined jaw 3c of the spring collet 3. After that, when the tool pulling rod 7 is pulled, the drawbar 4 slides on the arcuate groove 4f on the ball portion 3b of the spring collet 3, and the contact surface 6b of the piece 6 slides on the action protrusion 3f, causing the drawbar 4 to slide over the jaw portion of the spring collet 3. 3c, the jaws 4a of the drawbar 4 engage the jaws 2 at the base of the main collect 2.
c is pulled in, the tip crest 2a is pushed along the slope of the trapezoidal groove 1c, and is displaced in the direction of exiting and closing the trapezoidal groove 1c, and the ridge 2a is pulled into the hole 1b, thereby opening the jaw 2.
b engages with the neck Tc of the pull stud Tb to draw the tool holder T, and the taper shank Ta is firmly fitted into the taper hole 1a. This retraction of the main collet 2 ensures that it is held securely against cutting forces.
When removing the tool, move the tool pulling bar 7 forward to move the drawbar 4 forward, and the main collet 2 is pushed out by the shoulder of the neck 4b of the drawbar 4, and the crest 2a falls into the trapezoidal groove 1c. Open and release the grip. However, the working protrusion 3f at the rear end of the spring collet 3 continues to be closed by the contact surface 6a of the piece 6, which advances at the same time as the drawbar, and the jaw 3c of the spring collet 3 is engaged with the neck Tc of the pull stud Tb. Although the tool is in a semi-clamped state, there is sufficient holding force to prevent the tool from falling. When the tool change arm rotates and the gripper grips the groove of the flange of the tool holder T and moves in the axial direction, the pull stud Tb pushes the arm 3d in the direction of opening the tip of the spring collet 3 using the engagement slope of the neck Tc. It is removed by bending it.

When it is necessary to manually attach or detach a tool, as with automatic attachment or detachment, if the clamping force from the spring collet 3 remains, a considerable amount of force will be required to pull it out, and there is a risk of injury from the recoil when the tool is pulled out. Therefore, the clamping force is completely removed. That is, the tool is held in the hand so that it does not fall out, and the tool pulling rod 7 is advanced as described above to place the tool in a semi-clamped state.At the same time, the auxiliary pulling rod 8 is advanced against the force of the spring 9 to close the contact surface of the piece 6. 6a from the working protrusion 3f at the rear end of the spring collet 3.
drop into the relief part 6b and touch the end face of the pull stud Tb with the tip of the drawbar 4 to loosen the taper fit. Since the operating protrusion 3f of the spring collet 3 is free, no gripping force is applied and the tool can be easily pulled out. When installing, if you insert the tool holder T in this state, the spring tip 3 will be in the open state, so the taper shank
Ta can be inserted without any resistance to the position where it touches the taper hole 1a of the main shaft 1, and when the tool pull-up rod 7 and the auxiliary pull-up rod 8 are pulled in, the main collet 2 is pulled, and the spring collet 3 is held at the tip by the piece 6. When closed, the pull stud Tb is tightly grasped.

Effects As detailed above, the present invention provides a spring collet with a spring action between the main collets, so that when a tool is automatically attached or detached, the spring collet is always in action before starting the tool exchange operation. In order to perform tool exchange with the tool in a half-clamped state, the automatic tool exchange arm is driven by a cam, allowing the exchange operation to be performed independently of other operations and without the need for confirmation, thereby reducing exchange time by several seconds. It has the effect of

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the operating state of the spring collet when the tool is clamped, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is a sectional view showing the operating state of the main collet.
The figure shows the end face of the main collet and spring collet, and is a sectional view taken along the line B-B in Figure 1. Figure 4 is a diagram showing the tool in a half-clamped state. Figure 5 is a diagram showing the tool in a fully unclamped state. It is. 1... Main shaft, 2... Main collect, 3... Spring collect, 4... Drawbar, 5... Leaf spring,
6... Piece, 7... Tool pulling rod, 8... Auxiliary pulling rod.

Claims (1)

[Claims] 1. In a main spindle that includes a plurality of collects that pull up the pull stud of a tool or tool holder attached to the main spindle, and a drive member that performs the tool clamping action and tool unclamping action of the collects, between the plurality of collects, etc. A plurality of arms having a spring action on the pull stud engagement side from a pivoting fulcrum of a rod interposed at an angular position and having its longitudinal direction in the axial direction of the main shaft, and having an opening/closing end on an arm farther from the fulcrum. a spring collet; an auxiliary pulling rod slidably inserted through the center of the tool pulling rod of the drive member; A piece that acts in the direction of closing the collet, and a member that constantly urges the piece and the auxiliary pulling rod in the backward direction,
A spindle tool clamping device characterized in that a spring collet remains in action when inserting and removing a tool.