JPS6190842A - Automatic tool mounting and removing device - Google Patents

Abstract

PURPOSE:To stably obtain tightening torque to a fixed value, by connecting and disconnecting an engaging member with a low speed output shaft and a draw bolt by a mechanical clutch and utilizing rotary energy in a system of the low speed output shaft for tightening of the draw bolt. CONSTITUTION:A reduction member G, using a small motor M as a driving source, is connected by a flexible shaft joint J, while an output shaft 21 of this reduction member G is enabled to move in an axial direction. While the output shaft 21 is engaged with a shaft cylinder 30', 31 by a helical protrusive strip 21c, and this shaft cylinder 30', 31, being urged by a weak spring 34 to a side of the motor M, is rotatably key fitted to a cylindrical unit 25 not turned by the output shaft 21 in a racing condition due to the brake action. While an engaging member, respectively engaging with a thrust part 50b and an engaging tooth 50c provided in the tail end of a draw bolt 50, is provided in the end of the output shaft 21 and the shaft cylinder 30', being automatically connected with the draw bolt 50 by advancing the output shaft 21 or the shaft cylinder 30' to be moved by a left and a right roll start of the output shaft 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic tool attachment/detachment device that automatically attaches and detaches tools and arbor to and from the spindle of a machine tool by driving a drawing bolt inserted into the spindle of a machine tool in the forward and reverse directions using an electric motor, and has a streamlined configuration. This is intended to stabilize the tightening torque.

"Prior art" A conventional automatic tool attachment/detachment device has a pair of connecting/disconnecting means that can slide in the axial direction between the low-speed output shaft of a reduction mechanism using a small motor as the drive source and the tail end of a drawing bolt (hereinafter referred to as "draw bolt"). The connecting/disconnecting means is connected by an actuator such as an electromagnetic clutch, a solenoid, or an air cylinder, which not only complicates the mechanism, but also makes the energizing circuit and electric motor ( A synchronizing member with the motor) is required. Furthermore, when the above-mentioned connecting/disconnecting means is a dog clutch, the toothed shape is such that slipping occurs when the draw bolt is tightened (when the specified torque is reached), so the torque fluctuates due to toothed wear, resulting in long-term damage. Stable tightening torque cannot be guaranteed over time. When the gear teeth slip, a large force acts on the gear teeth, leading to early wear. In addition, in the electromagnetic clutch method, when the main shaft is running at high speed, a part of the clutch is rotating, which causes vibration during heavy cutting, which can easily cause an accident in which the tool loosens.

``Object of the present invention'' The present invention was made in view of the drawbacks and problems of the conventional automatic tool attachment/detachment device described above, and does not require an actuator at all to connect and disconnect the engaging member between the low-speed output shaft and the draw bolt. This mechanical clutch uses the rotational energy (inertia) of the low-speed output shaft system to stabilize the tightening torque of the draw bolt at a constant torque value without applying excessive force to the clutch or ball, and loosens it by tightening it at the shaft end. It is an object of the present invention to provide an automatic tool attachment/detachment device that loosens the tool while applying a thrust load.

"Structure of the present invention" In order to achieve the above object, the present invention connects a reduction member using a small motor as a drive source with a flexible shaft joint, and
While making the output shaft of this speed reduction member movable in the axial direction,
A helical protrusion engages the shaft cylinder, and this shaft cylinder is attached to the motor side with a weak spring, and is keyed loosely to the cylinder that is not rotated by the idling output shaft due to the braking action.The tail end of the draw bolt Connecting members that engage with the thrust part and the meshing teeth provided on the output shaft and the shaft cylinder are provided on the output shaft tip and shaft cylinder, and when the output shaft starts rotating left or right, the output shaft or shaft cylinder moves forward and automatically connects with the draw bolt. This eliminates the need for the biasing member of the coupling member (clutch) and its biasing electric circuit, streamlining the configuration, as well as ensuring that the engagement and disengagement of the coupling member can be performed smoothly without any difficulty or shock. It is a mechanical clutch. Also, to loosen it, rotate the draw bolt while pushing down the shaft end. Therefore, we succeeded in stabilizing the tightening torque of the draw bolt to a constant torque value by using the rotational energy (inertia) of the output shaft system, and also in loosening it smoothly.

"Embodiment of the present invention" The automatic tool attachment/detachment device of the present invention will be described below with reference to an embodiment of the drawings. The automatic tool attachment/detachment device TL is attached to the top wall 2a (left wall in the illustration) of the spindle head 2 from which the tail end of the spindle 1 protrudes via a joint pipe 3 with several bolts (not shown). . The lower end ring 4a of the long tube body (body) 4 is connected by bolts 6, 7, etc. via a crange body 5 interposed between the joint tube 3 and a. A cylindrical casing 8 housing the deceleration member G is attached to the top end surface (the right end in the illustration) of the tube body 4 so as to be connected to the outer peripheral edge of a bearing flange 9 fixed with bolts (not shown). 10
is an upper (left side in the figure) bearing flange, which is fitted onto the top end and inner peripheral surface of the casing 8, and a small motor M is installed on the upper surface of this bearing flange 10. A small gear (pinion) 12 is fitted onto the rotating shaft 11 of the motor M via a flexible shaft joint J, and this small gear is loosely fitted onto the support shafts 13 and 14 that are bridged between the bearing flanges 9 and 10. The large diameter gears 15a and 16a of the intermediate gears 15 and 16 mesh with each other. And the small diameter gear side 15b of the intermediate gears 15 and 16
, 16b mesh with a driven gear 19 supported in the inner hole 4b of the tubular body 4 via bearings 17 and 18. The rotation of the rotating shaft 11 of the small motor M rotating at high speed is reduced to about 200 to 300 rpm by a driven gear 19, which is a known reduction member G. 20 is spline hole 1 of driven gear 19
9a, and the tail end of the output shaft 21 is connected to this inner hole 20a by a key 22. The above output shaft 21
The middle part of the tube body 25 has a throttle hole 2 which is rotatably supported by two bearings 23 and 24 in a large hole 4c formed in the center of the tube body 4.
It is loosely fitted and supported by 5a. Reference numeral 26 denotes a coil spring, which is press-fitted between the slider 20 and the thrust bearing 27 of the throttle hole 25a, and the elastic force of this spring 26 causes the output shaft 21 to
toward the motor M side, and the large diameter portion 2 on the tip side of the output shaft 21
The step edge 21b of 1a is pressed against the throttle hole 25a via the thrust bearing 28 and stopped. Note that 28' is a thrust bearing through which the cylindrical body 25 receives thrust toward the motor M side. A left-handed helical protrusion 21c is protruded from the outer periphery of the large diameter portion of the output shaft 21, and this is engaged with a female thread 30a that integrates the double-structure shaft cylinders 30' and 31. The outer periphery of the shaft cylinder 31 is connected to the large diameter inner hole 2 of the cylinder body 25.
5b so as to be slidable and rotatable. 30 is screw tube 3
1 is a ball pressurized with a spring 32, and the cylindrical body 2
A stop that engages with a concave portion of an uneven circumferential surface consisting of a peak portion 25e and a valley portion 25d formed on the outer periphery of the small diameter flange portion 25c of No. It has become a component.

Therefore, when the idling output shaft 21 rotates clockwise (in the tightening direction),
Smooth key 29 due to left-handed helical protrusion 21c
The cylindrical body 25 and the slidable shaft cylinders 30' and 31 move forward toward the draw bolt 50. On the other hand, when the output shaft 21 is rotated to the left (loosening direction), the protrusion 2 of the left-hand helix
1c, only the output shaft advances toward the draw bolt side.

Note that a thrust bearing 3 is provided on the end surface 31b of the shaft cylinder 31.
A coil spring 34 with a weak elastic force is connected to the flange body 5 through 3.
The shaft cylinder 31 is floated so that it does not fall by itself (in the figure, it does not move to the right). A spline hole 31a is formed in the inner hole of the shaft cylinder 31,
Furthermore, annular meshing teeth (claws) 21d are carved on the tip surface of the large diameter portion 21a of the output shaft 21. Above spline hole 3
1a and the meshing teeth 21d are the thrust shaft portion 5 of the large diameter portion 50a expanded at the tail end (left end in the illustration) of the draw bolt 50.
0b and annular meshing teeth 50c provided on this end surface, and when the shaft cylinder 31 moves forward, a spline connection (31a and 50
b) The meshing teeth 21d and 50c are connected as the output shaft 21 moves forward. The draw bolt 50 is slidable on a bearing sleeve 41 that is screwed into the tail end of the rear end 1a of the main shaft 1 supported by a bearing 40, and is slidable through a thrust bearing 42 and a disc spring group 43. The draw bolt 50, which is suspended from the end face of the large diameter portion 50a, can move toward the motor M, but is held toward the tip end of the main shaft 1 by the rigidity of the disc spring 43. The draw bolt 50 has its tip threaded portion 50d integrally connected to the female thread 51a of the draw bolt main body 51.
b looks into the inner part of the tapered hole 1b of the main shaft 1, and is in a relationship of meshing with a female screw 45 provided at the tail end of the tool holder TH to be inserted therein. In addition, the above draw bolts 50, 51
The tightening torque for each member M, 11 to 5 that rotates during tightening is
It is determined by an inertial energy of 0, and the tightening force is stable.

"Action of the present invention" The automatic tool attachment/detachment device TL of the present invention is It is configured as described above, and its operation will be explained below.

First, when installing the tool T1 into the tapered hole 1b of the spindle 1,
As shown in the figure, when the tool holder TH is inserted, the female screw 45 at the tail end lightly contacts the tip screw portion 51b of the draw bolt 51. Next, when the motor M is started to rotate clockwise by pressing a button or the like, the output shaft 21 is rotated through the deceleration member G.
rotates to the right at low speed.

Now, even though the shaft cylinders 30' and 31 are rotated together by the left-handed helical protrusion 21c of the large diameter portion 21a of the output shaft, the cylinder that supports this outer periphery via the loose key body 2
5 is fastened to the ball 30 of the stop member,
The shaft cylinders 30' and 31 whose rotation is stopped are the draw bolts 50.
, moves forward toward the 51 side.

As the shaft cylinders 30' and 31 move forward, the end thrust hole 31a abuts and engages with the thrust part 50b of the draw bolt 50,
When the thrust bearing 33 is stopped at the end surface 5b of the flange body 5, the forward movement of the shaft cylinder 31 is stopped. When the forward movement of the barrel is stopped, the rotational torque of the output shaft 21 causes the barrel and the cylinder body 25 to rotate clockwise together. At this time, the ball 30 of the stop member moves by the rotation of the cylindrical body while making a sound along the uneven circumferential surface. This rotational force rotates the draw bolts 50 and 51 to the right, screwing their tip screws 51b into the female screws 45, gradually compressing the disc spring 43 strongly, and the repulsive force of this compression force causes the draw bolts 51 to move toward the tool T.
1 into the tapered hole of the main shaft 1 and fix it. The tightening torque of the above draw bolt is for each rotating part M, 1
Defined by inertia from 1 to 50. When the output shaft stops at the end of the above tightening action, the flexible shaft coupling J attached to the rotating shaft 11 of the motor M
The torsional energy stored in the motor is released, and this reaction torque rotates the output shaft to the left. This reaction force is several tens of degrees
The output shaft rotates to the left by pushing the shaft cylinders 30' and 31 from the flange body 5 back toward the motor M side by the left-handed helical protrusion 21c, and actively pulls out the spline hole 31a from the spline portion 50b of the draw bolt 50. . In conjunction with this, the resilient force of the spring 34 allows the shaft cylinders 30', 31 to be smoothly disengaged from the draw bolt 50. In addition, as mentioned above, the inertia of rotating members M, 11 to 50 is adjusted to the flexible shaft joint J.
Since the draw bolt 50 is tightened through the
The tightening torque is stabilized, the shock during tightening is reduced, and the action of separating the meshing members 31a, 50b after tightening becomes smooth. When the tightening is completed, the sound of the ball 30 disappears, and by confirming this sound, it is possible to know that the tightening is complete. still,
Because no large force acts on the ball, it has excellent durability.

Subsequently, the releasing action of the tool T1 is performed by first starting the motor M to rotate to the left using the starting switch, so that the output shaft 21 rotates to the left at a low speed via the deceleration member G. Now, although the shaft cylinders 30' and 31 try to rotate together due to the left-handed helical protrusion 21c, the cylinder body 25 is held in place by the ball 30 of the stop member through the play key, so that rotation is prevented. The stopped shaft cylinders 30' and 31 are pressed against the bearing 28, and the output shaft 21 advances toward the draw bolt 50 due to the reaction. As a result, the meshing tooth 21d at the tip thereof is connected to the meshing tooth 50c at the tail end of the draw bolt. After this connection, the output shaft 21
While pushing the shaft of the draw bolt by the strong rotational torque, the cylinder 25, shaft cylinders 30', and 31 become integrated with the output shaft and begin to rotate to the left, and the draw bolt is rotated to the left to remove the tool T1 from the draw bolt. In this case as well, the draw bolt can be reliably loosened with less shock by the flexible shaft joint J. When the draw bolt is rotated to the left, the tool T1 comes off the draw bolt and is caught by hand. With this separation, the start switch is turned OFF and the motor M
When the motor is stopped, the output shaft 21 is moved back toward the motor by the spring 26, and the coupling member is removed.

"Effects of the Present Invention" According to the present invention, the reduction member using a small motor as the drive source is connected by a flexible shaft coupling, and the output shaft of this reduction member is movable in the axial direction, while the helical protrusion This shaft cylinder is applied to the motor side with a weak spring and is keyed loosely to the cylinder body which is not rotated by the output shaft in the idling state that generates the braking force, and the tail end of the draw bolt is engaged with the cylinder body. Connecting members that engage with the thrust part and the meshing teeth provided on the output shaft and the shaft cylinder are provided on the output shaft tip and shaft cylinder, and when the output shaft starts rotating left or right, the output shaft or shaft cylinder moves forward and automatically connects with the draw bolt. This eliminates the need for the biasing member of the coupling member and the biasing circuit, which streamlines the configuration, and also prevents the coupling member from engaging and disengaging, and does not apply a large force to the ball that accelerates wear. In addition to smooth operation, it has many other excellent effects, such as stabilizing the tightening torque of the draw bolt to a constant torque value by using the rotational energy (inertia) of the output shaft system.

[Brief explanation of the drawing]

FIG. 1 is an overall sectional view of the automatic tool attachment/detachment device of the present invention, and FIG.
The figure is a perspective view of the dog clutch, and FIG. 3 is an end sectional view of the torque limiter. TL...Automatic tool attachment/detachment device, M...Small motor, G...Reduction member, J...Flexible shaft coupling, 21...Output shaft, 21c...Helical protrusion, 30
'...Shaft cylinder, 30...Ball, 34, 26...Spring, 50, 5
1... Draw bolt, 25... Cylindrical body, 50b... Thrust part,
50c...meshing tooth, 50a...large diameter part, 21a...large diameter part, 3
1a...Spline hole, 21d...Meshing tooth, T1...Tool, 1
...Main shaft, 43...Disc spring.

Claims (1)

[Claims] In addition to being connected to a speed reduction member using a small motor or the like as a drive source, the output shaft of this speed reduction member can be moved in the axial direction via a flexible shaft joint at a suitable location, and the shaft is A stop member applies braking force to the shaft cylinder, and a weak spring applies it to the motor side, and when the motor is idling, a key is applied to the cylinder body that is not rotated by the stop member. The configuration is such that the output shaft rotates after the clutch is engaged, and a coupling member (clutch member) that engages the thrust part and meshing teeth provided at the tail end of the draw bolt is provided on the output shaft tip and shaft cylinder, respectively. Automatic tool attachment/detachment characterized by moving the output shaft or shaft cylinder forward by starting rotation to the left or right and automatically connecting it to the draw bolt, and then using the tightening reaction force to deflect and detach the connecting member by the force of the shaft coupling and the spring. Device.