Gear cutting – milling – or planing – Milling – With means to control temperature or lubricate
Reexamination Certificate
2002-01-09
2003-06-24
Briggs, William (Department: 3722)
Gear cutting, milling, or planing
Milling
With means to control temperature or lubricate
C408S059000
Reexamination Certificate
active
06582167
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a spindle device of a machine tool spouting spray coolant from the tip of a tool.
BACKGROUND OF THE INVENTION
As to machining by machine tools, much coolant is supplied into machining points to cool and lubricate workpieces and tools, or to eliminate cutting chips. In this case, there are many problems, such as ill effects to an environmental pollution and human health due to coolant, high cost resulting from waste oil disposal of the coolant, shortening the life of a tool resulting from undercooling the workpieces, and sliding friction due to excessive coolant at a minute slitting of the tool. Besides, much coolant adheres to the cutting chips in machining, and therefore, when treating and recycling cutting chips, the adhesive coolant must be separated.
In recent years, to settle the above problems, there appear machine tools performing so-called dry cutting that cut as supplying spray into machining points. Here, the spray is formed from a very small quantity of coolant.
Applicant has already practiced machine tools for the dry cutting, for example, their spindle device is like
FIG. 5
or FIG.
6
.
First, an explanation about
FIG. 5
will follow. Numeral
2
is a spindle,
7
is a draw-bar, and
11
is a clamp-rod. Here, the draw-bar
7
is provided in the center of the spindle
2
, and the clamp-rod
11
is screwed on the tip of the draw-bar
7
. Besides, an in-spindle spray coolant passage
102
is provided over both centers of the draw-bar
7
and the clamp-rod
11
. Numeral
18
c
is a tapered interfitting axis of a tool holder
18
, which is closely fitted into a tapered interfitted hole
5
a
provided in the tip of the spindle
2
, pulled backward f
2
by a collet
12
, and comes to be in grasp. Numeral
14
is an atomizing nozzle for coolant,
103
is an in-holder spray coolant passage provided in the center of the tool holder
18
. The front end of the passage
103
opens to the tip face of the tool fixed on the tool holder
18
, and the rear end thereof opens to a bottom face of a cavity “b” provided in the center of the tapered interfitting axis
18
c.
Next, an explanation about
FIG. 6
will follow. A canister
25
is fixed at the center of the spindle
2
, and a steel ball
26
is supported on a through hole
25
a
on a peripheral wall of the canister
25
so as to be displaced in radial direction. The steel ball
26
is pushed to a wedge-shaped cavity
27
in accordance with the backward displacement of the clamp-rod
11
combined with the draw-bar
7
, displaced in outward radial direction of the canister
25
, and fitted into a circular hole b
1
provided on a peripheral wall of the tapered interfitting axis
18
c
of the tool holder
18
, thereby pulling the tapered intermitting axis
18
c
backward f
2
. Hence, the tapered interfitting axis
18
c
comes to be in grasp. The others are same with those of FIG.
5
.
In
FIG. 5
or
FIG. 6
, spray coolant spouts from an outlet of the atomizing nozzle
14
within the spindle
2
into the in-spindle spray coolant passage
102
. The spouted spray coolant flows into the cavity “b” of the tool holder
18
from the front opening of the clamp-rod
11
, and then flows out the air from the tip of the tool through the in-holder spray coolant passage
103
and a spray coolant passage provided in the center of the tool fixed on the holder
18
.
According to this kind of machine tool, even if the tool cuts deep position of a workpiece, its machining point is effectively lubricated by the spray coolant spouted from the tip of the tool. Accordingly, cutting is rationally accomplished.
However, according to the above conventional machine tool, the spray coolant reached the inside of the cavity “b” of the tool holder
18
flows out the air through an opening between parts. Therefore the coolant is wasted.
Besides, since the cavity “b” has a comparative large diameter in comparison with its front and back passages, the spray coolant reached the cavity “b” is liquefied. The liquefaction hinders the coolant from being stably supplied to the machining point of the workpiece, and does harm to a response to start or stop spouting the spray coolant from the tip of the tool.
Objects of the present invention are to provide a spindle device of a machine tool which can settle the above problems.
SUMMARY OF THE INVENTION
To achieve the above objects, in a spindle device of the present invention, as shown in claim
1
, a machine tool fixs mechanical-detachably a tool holder on the tip of a spindle by collet-clamping means. A mouthpiece member in a fixed length is protrudently installed on the bottom face of a cavity formed in the center of the tool holder with a screw. A gas-liquid passage, an atomizing means and an in-spindle spray coolant passage are provided in the center of a draw-bar of a spindle side clamping means. The atomizing means comprises an atomizing nozzle and a compressed air supplying valve. The atomizing nozzle mixes and stirs coolant and compressed air which are supplied from the outside of the spindle through the gas-liquid passage, and generates spray coolant. When pressure of the spray coolant spouted into the in-spindle spray coolant passage in front of the nozzle falls, the compressed air supplying valve is displaced forward a little, and directly blows the compressed air within a compressed air passage into the spray coolant. The in-spindle spray coolant passage is formed from an inner hole of the compressed air supplying valve, and contacts on the rear end of the mouthpiece member of the above tool holder.
Accordingly, the in-spindle spray coolant passage, the in-holder spray coolant passage, and the extension passage are hardly different in their diameters, and are closely communicated with each other. Therefore, the spray coolant passing these passages is prevented being liquefied by vast differences between their diameters, and stably spouting from the tip of a tool of the tool holder. Besides, since these passages are closely connected, the spray coolant is prevented flowing out the air in vain through an opening between parts. Moreover, since the extension passage is provided to the tool holder, a structure of the conventional spindle side can be used as it is.
This invention can be materialized as follows.
That is, as shown in claim
2
, an external form of the compressed air supplying valve is formed in one having level difference of a large diameter portion and a small diameter portion. The small diameter portion is located in an central hole of a joint screw fitted in an inner hole of a clamp-rod of the clamping means. A spring is provided between the joint screw and the level difference, and presses the compressed air supplying valve to the atomizing nozzle side.
In this case, as shown in claim
3
, when fastening the tool holder, the tip of the small diameter portion of the compressed air supplying valve is partially inserted into the rear end of the mouthpiece member of the tool holder.
Moreover, in the tool holder of the present invention, the extension passage is provided in the center of the bottom face of a comparative large diameter cavity provided on a tapered intermitting axis in the state that the in-holder spray coolant passage provided in the center of a holder body is extended backward. Accordingly, conventional clamping means can be almost used as it is.
In this case, the extension passage may be provided so as to go in and out in its longitudinal direction, as well as so as to be pressed backward by spring force.
REFERENCES:
patent: 5676506 (1997-10-01), Sugata
patent: 5690137 (1997-11-01), Yamada
patent: 5755537 (1998-05-01), Lubbering
patent: 5762454 (1998-06-01), Yamada
patent: 5860776 (1999-01-01), Sato et al.
patent: 5984595 (1999-11-01), Mizoguchi
patent: 6305696 (2001-10-01), Sugata et al.
patent: 62-15055 (1987-01-01), None
patent: 9-192963 (1997-07-01), None
patent: 9-239637 (1997-09-01), None
patent: 2000-736 (2000-01-01), None
patent: 2000-158285 (2000-06-01), None
Kobayashi Takashi
Seo Yoshihide
Sugata Shinsuke
Briggs William
Horkos Corp.
Shannon John P.
Venable LLP
LandOfFree
Spindle device of machine tool does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spindle device of machine tool, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spindle device of machine tool will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3154059