JP2000308946A - Toolholder with fluid passage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a degradation in the durability of toolholders even when they use mist. SOLUTION: A seal mechanism is disposed in a space 17 in practically symmetric posture relative to a fluid passage 8 through a holder body 1 in order to prevent mist out of a fluid passage through a housing 13 from leaking toward bearings 14. Inside each bearing 14 is rotatably disposed a first retaining ring 31 on the periphery of which a first O-ring 32 is arranged so as to be seated in an annular groove 13a cut in the housing 13. Inside each first retaining ring 31 are, in outer-to-inner order, a seal ring 33, a second retaining ring 34, a second O-ring 35 and a presser ring 36. A compression spring 37 is interposed between the presser rings 36 on the opposite sides of a peripheral opening 8a. The first and second retaining rings 31 and 34 have sliding movement on surfaces along the axis of the seal rings 33, the first and second O-rings 32 and 35 offer a radial seal, and the seal rings 33 provide an axial seal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder with a fluid path for ejecting a fluid such as a mist from the tip of a tool.

[0002]

2. Description of the Related Art Conventionally, a tool holder adopting a so-called side-through system in which oil is introduced from the side and injected from the tip of a tool is disclosed in, for example, Japanese Utility Model Laid-Open No. 58-8549 and Japanese Utility Model Laid-Open No. 58-169939. It is disclosed in Japanese Utility Model Application Laid-Open No. 17933/1985. This type of tool holder includes a holder body fitted on a main shaft of a machine tool, a housing rotatably provided on an outer peripheral surface of the holder body via a bearing, It is composed of a connection mechanism connected to a connection block of the machine. Each of the connection mechanism, the housing, and the holder body is provided with an oil path for guiding oil from the connection block to the tool.

[0003] Bearings for connecting the holder body and the housing are disposed on both sides of a communicating portion between an oil passage of the holder body and an oil passage of the housing, and an O-ring near the communicating portion for preventing oil from leaking to the bearing side. And lip packing is arranged. These O-rings and lip packings are pressed against the outer peripheral surface of the holder main body and the inner peripheral surface of the housing by the pressure of the oil present in the communicating portion. Particularly when the oil pressure is high, the outer peripheral surface of the holder main body and the housing It is designed to be strongly pressed against the inner peripheral surface. Since the O-ring and the lip packing slide on the outer peripheral surface of the holder main body and the inner peripheral surface of the housing, frictional heat is generated therebetween. Heat generation is prevented.

[0004]

In recent years, from the viewpoint of environmental protection and the like, a tool holder employs a system in which a small amount of oil is mist-formed and sprayed, that is, a so-called minute lubrication (MQL: minimum quantity lubrication) system. A mist comprising fine oil particles and air is sprayed to a processing point.

However, when the holder body rotates at a high speed, oil can absorb frictional heat to a certain extent, but mist cannot often absorb frictional heat sufficiently because air has a low cooling capacity. For this reason, in the conventional example, O
There is a problem that the ring and the lip packing are severely worn, and the holder body and the housing are also worn, and their durability is reduced.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a tool holder with a fluid path that does not reduce durability even when mist is used.

[0007]

According to the present invention, there is provided a tool holder with a fluid passage having a fluid passage communicating from a peripheral surface opening to an end surface opening on a tool side. In a tool holder with a fluid path, comprising a housing rotatably provided on the holder main body via bearings located on both sides of the opening, an outer seal for sealing a radial direction is provided on both sides of the peripheral surface opening. An inner seal is disposed via the respective outer ring member and the inner ring member, and a seal ring for sealing in the axial direction is disposed between the outer ring member and the inner ring member.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a partial cross-sectional view of the embodiment, and is configured so that a mist composed of fine particles such as oil and air can flow. The holder main body 1 has a front end face 1a on a side for holding a tool and a rear end face 1b on a side to be fitted to a main shaft of a machine tool.
A screw portion 2, a small diameter portion 3, a concave portion 4, a groove portion 5, and a tapered portion 6 are sequentially formed from the side a. And the holder body 1
Inside the small diameter portion 3, a fluid passage 7 having an end face opening 7 a in the front end surface 1 a and a diametrical direction extending from the deep portion of the fluid passage 7 to the outer peripheral surface of the small diameter portion 3. Is formed. The groove portion 5 is a portion to be gripped by the manipulator of the tool changing device, and the taper portion 6 is a portion to be fitted to the main shaft of the machine tool.

A rotating member 9 for adjusting the protruding length of the tool is screwed into the fluid passage 7 of the holder body 1, and a collet 10 for gripping the tool and the collet 10 are driven. Moving member 11 is fitted. The moving member 11 is driven in a direction along the axis by a nut 12 screwed to the screw portion 2, and a chuck mechanism for gripping a tool by the collet 10, the moving member 11 and the nut 12 is configured.

A cylindrical housing 13 is rotatably held in the small diameter portion 3 of the holder body 1 via, for example, two bearings 14. The bearings 14 are arranged at intervals on both sides of the peripheral surface opening 8a, and the outer bearings 14 are fixed by retaining rings 16 via spacers 15. A space 17 is formed between the outer peripheral surface of the bearing 14, the outer peripheral surface of the holder body 1, and the inner peripheral surface of the housing 13, and the housing 13 has a fluid passage 18 extending radially from the space 17 and opening to the outer peripheral surface. Is formed.

A cylindrical member 22 is supported on a part of the outer peripheral surface of the housing 13 via a bracket 21, and a pin member 23 having a front end surface 23a and a rear end surface 23b is slidable inside the cylindrical member 22. Is fitted. Bracket 2
1, a fluid passage 24 communicating with the fluid passage 18 is formed. A fluid passage 25 communicating radially with the fluid passage 24 is formed in the pin member 23, and the fluid passage 25 and the rear end face 23b are oriented in the axial direction. And a fluid passage 26 communicating with the fluid passage.
A stopper member 27 that engages with the concave portion 4 of the holder body 1 and regulates the mutual rotation of the holder body 1 and the housing 13 is fixed to the outer peripheral surface of the pin member 23. The stopper member 27 is a cylindrical member. 22 is urged in the direction of engagement with the recess 4 by a compression coil spring 28 fitted on the outer peripheral surface of the recess 22.

Here, as shown in a partially enlarged view of FIG.
In the space 17, a seal mechanism for preventing the mist flowing from the fluid passage 18 of the housing 13 from leaking to the bearing 14 side is configured substantially symmetrically with the fluid passage 8 of the holder body 1. That is, the first holding ring 3 is provided inside the bearing 14.
1 is rotatably arranged so that the side surface thereof abuts the outer ring side surface of the bearing 14. On the outer peripheral surface of the first holding ring 31, the first O-ring 32
In the annular groove 13a. A minute gap 31a is provided between the inner peripheral surface of the first holding ring 31 and the outer peripheral surface of the holder main body 1, so that the first holding ring 31 can be easily rotated with respect to the holder main body 1. First O-ring 32
Has an inner diameter that protrudes from the annular groove 13a, and is smaller than the outer diameter of the first holding ring 31. As a result, the first holding ring 31 and the first O-ring 32
Is integrated with the housing 13 and is radially sealed.

Inside the first retaining ring 31, a seal ring 33, a second retaining ring 34, a second O-ring 3
5. The holding ring 36 is sequentially arranged. The press ring 36 is arranged near the peripheral opening 8a, and a compression coil spring 37 is arranged between the press rings 36 located on both sides of the peripheral opening 8a. The outer peripheral surface of the second O-ring 35 in the radial direction is formed by the holding portion 3 of the second holding ring 34.
The surface of the second O-ring 35 which is pressed by 4 a and faces in the direction along the axis of the second O-ring 35 is pressed by the pressing portion 36 a of the pressing ring 36. As a result, the second holding ring 34, the second O-ring 35, and the holding ring 36 rotate integrally with the holder body 1 and are sealed in the radial direction.

The surface of the seal ring 33, which faces in the direction along the axis, is pressed by the first holding ring 31 and the second holding ring 34, and is sealed in the axial direction. The seal ring 33 is formed in an O-ring shape from a material obtained by mixing carbon fibers with a fluorine resin, for example, Teflon (trade name). The amount of carbon fiber added is appropriately adjusted so that a small amount of friction of the seal ring 33 is promoted, and a Teflon film is always generated on the friction surface.

While the manipulator of the automatic tool changer is holding the groove 5 of the holder body 1, the stopper member 27
Engages with the concave portion 4 of the holder body 1 by the urging force of the compression coil spring 28, and the holder body 1 and the housing 13 do not rotate with each other. When the manipulator pushes the tapered portion 6 of the holder body 1 into the main shaft of the machine tool, the pin member 2
3 moves forward by the action of the connection block of the machine tool, and the stopper member 27 comes off the recess 4 so that the holder body 1
Can be rotated.

In this state, the mist flows from the connection block through the fluid passages 26, 25, 24 and 18 into the space 17, and the mist in the space 17 is ejected from the tip of the tool through the fluid passages 8 and 7. . At this time, the pressure of the mist together with the urging force of the compression coil spring 37 presses the holding ring 36 toward the first holding ring 31, and the first holding ring 31
Of the seal ring 33 slides on surfaces facing in the direction along the axis of the seal ring 33, and the first O-ring 32, the seal ring 33, and the second O-ring 35 move in the radial and axial directions of the mist. Prevent leaks.

As described above, in the embodiment, since the first holding ring 31 and the second holding ring 34 slide on the surfaces facing the direction of the axis of the seal ring 33, the portion where the friction occurs is the seal ring. 33, and the durability of the seal ring 33 is improved. Further, since the first holding ring 31 and the second holding ring 34 are pressed against the seal ring 33 by the pressure of the mist and the urging force of the compression coil spring 37, the sealing force of the seal ring 33 is improved. Furthermore, the seal ring 33 is used for the holder body 1 and the housing 13.
Does not slide with respect to the holder body 1 or the housing 1
3 are not worn, and their durability is also improved.
When the seal ring 33 is worn, the sealing force is restored by replacing the seal ring 33 alone.

As shown in the front view of FIG. 3 and the sectional view of FIG. 4, the surface facing the first ring 31 in the direction along the axis of the seal ring 33 'made of a conventional material has a depth of 1 m.
Even if a plurality of cuts 33a within m are formed, the same effect as the seal ring 33 of the embodiment can be achieved. When this seal ring 33 ′ is used, the mist is cut 33
a, the lubricating efficiency is improved by flowing into the bearing 14, and the temperature of the outer peripheral surface of the housing 13 is lowered by about 40 ° C. as compared with the conventional case.

Further, not only the first holding ring 31 side of the seal ring 33 'but also the second holding ring 3 on the opposite side.
A plurality of cuts 33b may also be formed on the four sides with a phase shift. In this case, since the mist also flows into the cut 33b, the frictional resistance between the mist and the second holding ring 34 can be reduced, and a further effect can be achieved.

In the embodiment, the use of the mist has been described, but it goes without saying that a liquid such as oil can be used. Further, the compression coil spring 37 for urging the holding ring 36 toward the first holding ring 31 is provided. When the pressure of the mist is high, the pressure replaces the action of the compression coil spring 37. Is also possible. Then, the seal ring 33 'is added to the seal ring 33 of the embodiment.
It is needless to say that notches similar to the notches 33a and 33b may be formed.

[0021]

As described above, in the tool holder with a fluid path according to the present invention, since the outer ring and the inner ring slide with respect to the seal ring, a portion where friction occurs is distributed on two surfaces of the seal ring. Thus, the durability of the seal ring is improved. Further, since the seal ring does not slide with respect to the holder main body and the housing, the holder main body and the housing do not wear, and their durability is also improved. If a cut is formed on the surface of the seal ring that faces in the direction along the axis, the fluid flowing into the cut reduces friction, thereby suppressing heat generation of the seal ring and further improving durability.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of an embodiment.

FIG. 2 is a partially enlarged view.

FIG. 3 is a front view of a modified example of the seal ring.

FIG. 4 is a sectional view of a modification of the seal ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Holder main body 7, 8, 18, 24, 25, 26 Fluid path 8a Peripheral opening 13 Housing 14 Bearing 17 Space 31, 34 Holding ring 32, 35 O-ring 33, 33 'Seal ring 36 Pressing ring 37 Compression coil spring

Claims (5)

[Claims] 1. A holder main body having a fluid passage communicating from a peripheral opening to a tool-side end surface opening, and a housing rotatably provided on the holder main body via bearings located on both sides of the peripheral opening. In the tool holder with a fluid path, an outer seal and an inner seal for sealing in the radial direction are arranged on both sides of the peripheral surface opening via respective outer ring members and inner ring members, and the outer ring member A tool ring with a fluid path, wherein a seal ring for sealing in an axial direction is arranged between the inner ring member and the inner ring member. 2. The tool holder with a fluid path according to claim 1, further comprising an urging means for urging the inner ring member toward the outer ring member. 3. The tool holder with a fluid path according to claim 1, wherein the outer ring member rotates integrally with the housing, and the inner ring member rotates integrally with the holder body. 4. The tool holder with a fluid path according to claim 1, wherein a notch is formed in a surface facing a direction along an axis of the seal ring. 5. The tool holder with a fluid path according to claim 2, wherein the urging means urges the inner seal via a holding ring member.