JPH0333404Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a support structure for a rotary joint that connects the rear end side of a drawbar in the main spindle of a machine tool and an oil supply pipe on the stationary side. The present invention relates to a support structure for a rotary joint suitable for preventing rotational vibration of the rotary joint due to rotation.

BACKGROUND OF THE INVENTION A drawbar is supported within the spindle of a machine tool, particularly a machining center. The drawbar is reciprocated in the axial direction within the main spindle, and grips and fixes a tool fitted into the main spindle within the main spindle. Further, the drawbar is generally connected to a stationary side oil supply device by a rotary joint, and the inside thereof is configured to be oiled. That is, the rotary joint is composed of two sets of members, one member is connected to the oil supply device on the stationary side and smoothes the reciprocating movement of the drawbar, and the other member is a member for connecting with the rotating drawbar.

In conventional machine tool spindle core lubrication systems, the rotary joint is placed behind the spindle and is in a free state where it is not supported by the stationary side. For this reason, the rotary joint flexes due to its own weight, and especially when the main shaft rotates at high speeds (8,000 rpm to 10,000 rpm), the runout becomes large and causes a problem in that the main shaft vibrates.

A conventional drawbar, a rotary joint, and a reciprocating operation of the drawbar will be briefly explained based on the drawings.

As shown in FIG. 2, the drawbar 15 is supported by a main shaft 17 and grips a pull stud 21 of a tool 20 via a tool collet 19. An oil passage 22 is provided within the drawbar 15. The end portion of the drawbar 15 is connected to the oil supply device 12 on the immovable side via a rotary joint 11. The first member 9 of the rotary joint 11 smoothes the reciprocating movement of the drawbar 15, and the second member 10 is a member that connects the rotating drawbar 15 and the shaft within the first member 9. Drawbar 15 inside main shaft 17
A piston 34 is provided between the rotary joint 11 and the rotary joint 11 . The reciprocating movement of the drawbar 15 is caused by the leaf spring 18 of the main shaft 17 when the drawbar 15 grips the tool 20.
The drawbar 15 releases its grip on the tool 20 when the sliding member 30 inside the piston 34 slides on the outer periphery of the drawbar 15 in the axial direction. This is done by pressing the pressing member 16 fixed above. That is, as shown in arrow E, air pressure presses the protrusion 31 of the sliding member 30, and the sliding member 30 slides within the gap chamber 32, moves forward by a distance A, and comes into contact with the pressure contact member 16. , and press this to move the drawbar 15 toward the tool 20. As a result, the tool collet 19 opens one end of the grip side and pulls the pull stud 21.
Release the grip.

The drawbar 15 rotates at high speed together with the main shaft 17,
Since the rotary joint 11 has nothing to support it and is in a free state, rotational vibration occurs due to its own weight.
As a result, the drawbar 15 and the tool 20 also generate rotational vibrations, causing defects in machining.

Problems to be Solved by the Invention The present invention attempts to solve the above-mentioned problems, and its purpose is to prevent rotational vibration of the rotary joint that connects the oil supply device on the rear end side of the drawbar and the stationary side;
An object of the present invention is to provide a support structure for a rotary joint that improves the machining accuracy of a machine tool.

Means for Solving the Problems In order to achieve the above object, the present invention provides a movable member that engages with a drawbar and moves the drawbar along the axis of the main shaft, the movable member being connected to the stationary side of the machine and the rotary joint. The drawbar is interposed removably between the outer peripheries, and when the drawbar moves in a direction to be gripped within the main shaft, an inclined surface formed at one end thereof is pressed against the inclined surface on the immovable side, and the outer periphery of the rotary joint is The means for this purpose is a support structure for a rotary joint which is provided with a collet-like member that holds the rotary joint on the immovable side.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIG. 1, the same reference numerals as those shown in FIG. 2 indicate the same components or components with the same function.

As shown in FIG. 1, the rear end side of the drawbar 15 is connected to the oil supply device 12 by a rotary joint 11B.
The rotary joint 11B is connected to the first member 9 as in the prior art.
and a second member 10. A shaft 13 is rotatably and axially slidably supported within the first member 9 . An oil passage 22 is provided within the shaft 13 and is connected to an oil passage 22B provided within the outer peripheral member of the first member 9. Second member 1
0 removably connects the rear end of the drawbar 15 and the shaft 13. A pressure contact member 16 is fixed on the outer periphery of the drawbar 15 between the second member 10 and the main shaft 17.

A collet-shaped member 1 is disposed on the outer peripheral side of the rotary joint 11B. The collet-shaped member 1 is arranged so as to straddle the first member 9 and the second member 10 and wrap around the outer peripheries thereof. The collet-like member 1 is supported at its outer side via an intervening member 3 on a stationary side 4 so as to be slidable in the axial direction.

One end side of the collet-like member 1 is fitted in contact with the outer periphery 14 of the first member 9, and is slidable on the outer periphery 14 of the first member 9 in the axial direction. The outer peripheral side of this one end side of the collet-like member 1 forms an inclined surface 2 toward the end of the first member 9. The intervening member 3 facing the inclined surface 2 has the same inclined surface as the inclined surface 2, and the two inclined surfaces are joined or separated when the collet member 1 slides and reciprocates along the axial direction.

The other end of the collet-like member 1 faces the pressure member 16 with a distance m therebetween.

A gap chamber 6 is provided between the intervening member 3 and the collet-like member 1, and the gap chamber 6 is connected to an air passage 5 provided in the stationary side 4. A gap chamber 8 is provided between the stationary side 4 and the collet-like member 1, and the gap chamber 8 is connected to an air passage 7 provided in the stationary side 4.

During machining, the drawbar 15 is moved toward the rear end by the repulsive force of the leaf spring 18, and the tool collection 19
The other end is closed and the pull stud 21 of the tool 20 is gripped, and the main shaft 17 and drawbar 15 are rotated to perform machining. At this time, air pressure is supplied from the air passage 7 into the cavity chamber 8 . As a result, the collet-shaped member 1 is moved toward the first member 9, and the inside of the inclined surface 2 slides on the outer circumferential surface 14 of the first member 9. The inclined surface 2 fits into the inclined surface of the intervening member 3 and stops. Therefore, the first member 9 is supported on the stationary side 4 via the collet-like member 1 and the intervening member 3. A shaft 13 within the first member 9 is connected to a drawbar 15 via a second member 10, and is supported within the first member 9 to rotate. Even when the drawbar 15 rotates at high speed, one end side is supported by the member 9 on the immovable side, so the rotary joint 11B composed of the first member 9 and the second member 10 does not generate rotational vibration. figure,
Further, the drawbar 15 also does not generate rotational vibration.

During machining, cutting oil, etc. flows from the oil supply device 12 to the oil path 22.
The oil passage 22 and the machining location of the tool 20 are supplied with oil through B.

When the spindle 17 is stopped for automatic tool exchange or the like, air pressure is supplied to the air passage 5 in the stationary side 4. Therefore, the collet-shaped member 1 is moved a distance m toward the main shaft 17 by being pressed by air pressure, and the inclined surface 2 is moved toward the intervening member 3.
away from the inclined surface.

The other end of the collet-like member 1 contacts and presses the pressure contact member 16. Therefore, the drawbar 15 fixed to the pressure contact member 16 moves toward the tool 20 against the repulsive force of the leaf spring 18, opens one end of the tool collet 19, releases the gripping pull stud 21, and removes the tool automatically. An exchange takes place.

As described above, the rotational vibration of the rotary joint can be prevented by using the conventional rotary joint 11, and the mechanism can be simplified by eliminating the piston 34 of the prior art.

Effects of the invention As is clear from the above explanation, according to the invention,
It is possible to prevent rotational vibration of the rotary joint, thereby preventing vibration of the tool held by the drawbar, and to improve the machining accuracy of the machine tool. Further, by omitting a piston for pressing the drawbar, the mechanism can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of one embodiment of the present invention, and FIG. 2 is a side sectional view of the prior art. 1... Collet-shaped member, 2... Inclined surface, 3...
Intervening member, 4... immovable side, 5, 7... air path,
6, 8, 32...Void chamber, 9...First member, 1
0... Second member, 11, 11B... Rotating joint,
12... Oil supply device, 13... Shaft, 14... Outer peripheral surface, 15... Drawbar, 16... Pressing member, 17
... Main shaft, 18 ... Leaf spring, 19 ... Tool collection, 20 ... Tool, 21 ... Pull stud, 2
2, 22B...Oil passage, 30...Sliding member, 31...
...Protrusion, 34...Piston.

Claims (1)

[Scope of utility model registration request] In a support device for a rotary joint that connects a rear end side of a drawbar in a main shaft of a machine tool and an oil supply pipe on a stationary side, a moving member that engages with the drawbar and moves the drawbar along the axis of the main shaft. It's hot,
The drawbar is inserted and removably inserted between the stationary side of the machine and the outer periphery of the rotary joint, and when the drawbar moves in the direction of gripping a tool within the main shaft, the slope formed at one end of the drawbar is inserted into the stationary side. 1. A support structure for a rotary joint, comprising a collet-like member that presses against an inclined surface of the rotary joint and holds the outer periphery of the rotary joint on the immovable side.