JPH09314435A - Automatic chuck opening/closing mechanism of spindle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck opening/closing mechanism of a spindle capable of rapidly changing a tool by automatically opening/closing a chuck. SOLUTION: An automatic chuck opening/closing mechanism is provided with a chuck 10 to hold a tool, a spindle shaft 20 to store the chuck inside and integratedly rotate it, and a housing 30 to fix the spindle shaft through bearings 17, 18, and the mechanism is provided in the spindle to open/close the chuck 10 by longitudinally moving the chuck 10 in the longitudinal direction. Two oblong holes 22 are provided in the spindle shaft 20, and a pin member 14 which is integratedly moved with the chuck in the longitudinal direction is passed in the oblong holes 22. In the normal condition, a spring member 16 presses the chuck backward through the pin member 14, etc. When an air compressor is operated, a cylinder 40 provided in a space S of the housing 30 receives the air pressure from the back side, and is moved forward, and the chuck 10 is moved forward against the pressing force of the spring member 16 through the pin member 14, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic chuck opening / closing mechanism for a spindle, and more particularly to an automatic chuck opening / closing mechanism suitable for a spindle attached to a main body of a processing apparatus such as a dedicated machine for boring a printed circuit board.

[0002]

2. Description of the Related Art Since the opening / closing operation of a chuck in a spindle of a conventional processing apparatus is manually performed by using a spanner, a wrench or the like, there has been a problem that it takes time to replace a tool. Therefore, for example, when performing drilling work of several types of hole diameters by a dedicated machine for drilling holes in printed circuit boards, multiple types of tools corresponding to each hole diameter are chucked on each of multiple spindles, and each spindle is attached to the machine body. Each tool was used either by replacement or by attaching the spindle to the machine body and moving the spindle up and down.

[0003]

However, in that case, there is a problem that the cost becomes high and the machine body becomes large because a plurality of kinds of spindles must be prepared.

The present invention has been made in view of the above problems, and an object thereof is to provide a chuck opening / closing mechanism for a spindle which can automate the opening / closing of the chuck to promptly exchange a tool. To do.

[0005]

SUMMARY OF THE INVENTION An automatic chuck opening / closing mechanism for a spindle according to the present invention (this mechanism) includes a chuck for holding a machining tool and a spindle shaft for accommodating the chuck inside and rotating integrally. And a housing for fixing the spindle shaft via a bearing, and is designed such that when the chuck moves forward in the spindle shaft, the tip of the chuck opens and when the chuck moves backward, the tip closes. It is provided on the spindle.

Examples of the processing device to which the spindle is attached include a drilling machine dedicated to a printed circuit board and a small diameter drilling machine.

Further, the structure for opening and closing the tip portion of the chuck by moving the chuck forward and backward within the spindle shaft is generally provided with a slit from the tip of the chuck, and
The outer diameter of the chuck tip portion is enlarged, and the enlarged portion is put in and out of the spindle shaft, and those engaging portions are tapered.

In this mechanism, the spindle shaft is bored,
Two elongated holes that are diametrically opposed to each other and that are long in the axial direction, and a pin member that moves back and forth integrally with the chuck and that projects from the elongated hole to the outside in the radial direction from the outer peripheral surface of the spindle shaft. A spring member that constantly presses the chuck rearward in the spindle shaft to such an extent that the chuck is surely closed through the pin member; and a moving member that is movably provided in a space defined inside the housing. , A fluid feeding means for feeding a fluid into a space where the rear surface of the moving member is exposed.

The axial length of each elongated hole is set so that the pin member can move along each axial hole to open and close the chuck.

The pin member is a transmission member for transmitting the pushing force of the spring member to the rear side and the force of the moving member pushed forward by the air pressure to the chuck, and the transmission member includes an appropriate member other than the pin member. But it's okay. Moreover, although air is desirable as the fluid and as the fluid,
The mechanism can be hydraulic using oil.

A compressor or the like can be used as the fluid feeding means, and the opening and closing of the joint portion may be switched by a solenoid valve.

In this mechanism, when the fluid feeding means is actuated to feed the fluid to the gap, the moving member receives the fluid pressure from the rear surface and moves forward, and the chuck moves through the pin member. Is moved forward against the pressing force of the spring member. As a result, the chuck is opened and the tool is attached / detached.

Further, if the operation of the fluid feeding means is stopped or the valve is closed while the chuck is open, the pressurization of the fluid to the moving member is sharply reduced. It moves backward, the chuck closes, and the tool is held. At this time, the fluid in the void may be positively drawn to the outside.

Further, it is possible to cause the spring member to bear the force of moving the moving member rearward and returning it to its original position. However, together with this spring member, the force for surely returning the moving member to its original position is provided. It is also possible to provide a separate spring to bear.

Further, in order to make the fluid pressure work effectively, the gap is made airtight or watertight by a suitable sealing material.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a spindle 1 attached to a hole punching machine (not shown) dedicated to a printed circuit board. The spindle 1 includes a chuck 10 for holding a drill (not shown) as a tool, and a spindle shaft 20 for accommodating the chuck 10 in a substantially cylindrical front half portion 20a.
And two ball bearings 17 and 18 for supporting the spindle shaft 20 and two ball bearings 17 and 18 for supporting the spindle shaft 20, and a housing 30 for supporting the spindle shaft 20 via the bearings 17 and 18.

A tip end portion 20 'of the spindle shaft 20 is provided with a taper portion 21 whose inner diameter gradually increases toward the tip end, and a rear end portion 20 "of the motor connecting clutch 1 is provided.
9 are connected via pins 19 '. Further, in the vicinity of the rear end of the first half portion 20a of the spindle shaft, two elongated holes 22 which are diametrically opposed to each other and are long in the axial direction are formed.

The chuck 10 is a substantially cylindrical member whose outer diameter matches the inner diameter of the spindle shaft front half portion 20a. The tip portion 10 'has a thick wall, and the taper of the spindle shaft 20 is formed on the outer peripheral surface of this thick wall portion. Inclined portion 11 engaging portion 21
Is set. Further, the chuck 10 is provided with several slits 12 along the axial direction from the tip.

Therefore, the chuck 10 is attached to the spindle shaft 20.
When moved inward, the taper portion 21 of the spindle shaft 20 tightens the chuck tip 10 ′ through the engagement with the inclined portion 11 of the chuck 10, and the chuck 10 is closed. When the chuck 10 is moved forward in the spindle shaft 20 from this state, the tightening by the spindle shaft taper portion 21 is released and the chuck 10 is opened.

A chuck connecting rod 13 is concentrically screwed to the rear end portion 10 ″ of the chuck 10, and a connecting pin 14 is diametrically penetrated near the rear end of the chuck connecting rod 13. Both ends of the are projected radially outward from the outer peripheral surface of the spindle shaft 20 through the elongated holes 22 of the spindle shaft 20, and then are received by a moving ring 15 provided around the spindle shaft 20 so as to be movable in the axial direction. The moving ring 15 is provided at its rear end with a flange portion 15 'which projects outward in the radial direction in a flange shape.

Therefore, the spindle shaft 20, which is rotationally driven from the motor of the machine body (not shown) via the motor connecting clutch 19, has the connecting pin 1 inserted through the slot 22.
4 and the chuck 10 are integrally rotated via the chuck connecting rod 13.

A chuck spring 16 is provided around the spindle shaft 20 between the front end of the moving ring 15 and the inner ring of the front bearing 17 on the rear side. The chuck spring 16 includes the moving ring 15 and the connecting pin 14. Also, via the chuck connecting rod 13, the chuck 10 is constantly pressed rearward in the spindle shaft 20 to such an extent that the chuck 10 is securely closed.

The housing 30 has a housing body 30b which surrounds the spindle shaft 20 except for the vicinity of the tip portion 20 '.
And a housing cap 30a that is fitted into the housing body 30b from the front to fix the front bearing 17.

The housing body 30b has a cylindrical portion 31 which is substantially cylindrical in the front 2/3 and a rear portion 32 which is thickened radially inward in the rear 1/3 to fix the rear bearing 18. , A protruding portion 33 that protrudes forward from the radially inner portion of the rear portion 32 in the vicinity of the spindle shaft 20. Further, the protruding portion 33 has a relatively thin front half portion 33a and a rear half portion 33b thicker than the front half portion 33a.
And the outer peripheral surface of the projecting portion 33 is stepwise reduced in diameter from the rear half 33b to the front half 33a to define the step 33 ′.

A space S is defined in front of the housing rear portion 32 in the housing body 30b, and a cylindrical cylinder 40 as a moving member is accommodated in the space S so as to be movable in the axial direction. The cylinder 40 includes the front half 3 of the housing cylindrical portion 31 and the housing protruding portion 33.
A rear part 40b which is fitted between 3a and 3a,
The front portion 40 having an inner diameter larger than that of the rear portion 40b
a, and includes a front portion 40a of the inner peripheral surface of the cylinder 40.
A step 41 is set at the boundary between the rear portion 40b and the rear portion 40b.
The outer diameter of the flange portion 15 ′ of the moving ring 15 is equal to the inner diameter of the cylinder front portion 40a and the cylinder rear portion 40a.
It is set so as to come between the inner diameter of b.

A space S'remains behind the cylinder 40 in the space S, and this space S'opens to the outside via an air passage 52 and an air inlet 51 provided in the housing rear portion 32. A joint 50 is installed at the air inlet 51, and an air inlet source such as an air compressor (not shown) is connected to the joint 50.

On the other hand, a front surface 40 'of the cylinder 40 is provided with a plurality of rod members 42 projecting forward along the axial direction. These rod members 42 are wound with a cylinder return spring 43, and then the housing head 30a. It is received in a rod receiving hole 44 provided on the rear surface. The rod receiving hole 44 has a stepwise expanded diameter rearward, and the stepped portion 44 'functions as a spring receiver.

FIG. 1 shows a normal state of the spindle 1 in which the air supply source is not operating. The pressing force pushes the spindle shaft 20 rearward and closes the drill shaft to a certain extent. Also, the cylinder 40
Is pushed rearward by the urging force of the cylinder return spring 43 and is in contact with the step portion 33 ′ of the housing protruding portion 33. There is some clearance between the connecting pin 14 and the rear end of the slot 22. In the above state, the spindle shaft 20
Is rotated to perform a predetermined drilling process.

When replacing the drill with one having a different diameter, the rotation of the spindle shaft 20 is stopped and the air feed source is operated. As a result, air enters the space S ′ through the joint 50, the air inlet 51 and the air passage 52, and presses the rear surface 40 ″ of the cylinder 40 by the air pressure. In order to prevent air leakage from the space S ′, O-rings 45 and 46 are provided on the outer peripheral surface of the cylinder 40 and the inner peripheral surface of the cylinder rear portion 40b, respectively.

2, the cylinder 40, which receives air pressure on the rear surface 40 ", moves forward against the bias of the cylinder return spring 43. During this forward movement, the step 41 of the cylinder 40 is moved. Is the flange portion 15 'of the moving ring 15.
And the moving ring 15 is pushed forward against the pressing force of the chuck spring 16. As a result, the connecting pin 14 moves forward in the elongated hole 22, and accordingly, the chuck connecting rod 13 and the chuck 10 move forward in the spindle shaft to open the chuck 10 as described above. Replace the drill in this state.

After a new drill is attached to the chuck 10, the operation of the air feed source is stopped or the solenoid valve provided near the joint portion 50 is closed to remove air, and the air pressure on the rear surface 40 "of the spindle 40 disappears. The cylinder 40 returns to its original position due to the pressing force of the cylinder return spring 43 (see FIG. 1), and the moving ring 15 also returns to its original position due to the pressing force of the chuck spring 16 to move the chuck 10 inside the spindle shaft 20. The drill moves backward, the chuck closes again, and the drill is held.The above operations are performed instantaneously, so that the drill can be replaced quickly.

In the above embodiment, the cylinder 40
Although the return spring 43 is used to reliably return to the original position, it is also possible to return the cylinder 40 to the original position by, for example, making the space S ′ negative pressure. Further, the chuck opening / closing can be automated by a hydraulic type instead of a pneumatic type.

[0034]

As described above, in the automatic chuck opening / closing mechanism of the spindle according to the present invention, the back-and-forth movement of the chuck in the spindle shaft utilizes the movement of the moving member by the fluid pressure and the pressing force of the spring member. Since it can be automatically and quickly performed, attachment / detachment, holding, or replacement of the tool by opening and closing the chuck can be made significantly quicker than the conventional manual method.

Therefore, it is not necessary to prepare a plurality of spindles to be attached to the machine body.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a spindle with a chuck closed.

FIG. 2 is a cross-sectional view of the spindle in a state where the air supply source is activated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spindle 10 Chuck 11 Inclined part 12 Slot split 13 Chuck connecting rod 14 Connecting pin 15 Moving ring 16 Chuck spring 17,18 Ball bearing 20 Spindle shaft 20a Spindle shaft front half 21 Tapered part 30 Housing 30a Housing cap 30b Housing body 31 Housing Cylindrical portion of the main body 32 Rear portion of the housing main body 33 Protruding portion of the housing main body 33 ', 41, 44' Step portion 33a Front half of the protruding portion 33b Rear half of the protruding portion 40 Cylinder 40a Cylinder front portion 40b Cylinder rear portion 42 bar member 43 cylinder return spring 44 bar receiving hole 45,46 O-ring 50 joint 51 air inlet 52 air passage S space S'void

Claims (1)

[Claims] 1. A chuck for holding a machining tool,
A spindle shaft for accommodating the chuck inside and rotating integrally, and a housing for fixing the spindle shaft via a bearing are provided. When the chuck moves forward in the spindle shaft, the tip portion of the chuck is moved. An automatic chuck opening / closing mechanism provided on a spindle designed to close the tip when opened and moved rearward, comprising two diametrically opposed and axially long holes formed in the spindle shaft. With the elongated hole, a pin member that moves back and forth integrally with the chuck and that projects radially outward from the outer peripheral surface of the spindle shaft through the elongated hole, and the chuck secures the chuck through the pin member. A spring member that constantly pushes backward in the spindle shaft to the extent that A moving member and a fluid feeding means for feeding a fluid to a space where the rear surface of the moving member is exposed, and when the fluid feeding means is operated to send the fluid to the space, the moving member causes a fluid pressure from the rear surface. An automatic chuck opening / closing mechanism for a spindle, characterized in that the automatic chuck opening / closing mechanism is configured to move forward upon receipt of the force and to move the chuck forward via the pin member against the pressing force of the spring member.