JP2595522Y2 - Rotary joint for woodworking - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a woodwork having an axially small hole and a rotary joint for high-speed rotation for supplying gas such as air blown from a cutting edge of a working drill or an end mill or the like.

[0002]

2. Description of the Related Art Conventionally, in the metalworking industry and the like, a cutting oil is jetted from a cutting edge by using a tool with an oil hole (mainly a drill) for deep hole drilling and drilling of difficult-to-cut materials to thereby improve cutting performance and processing quality. Techniques for improvement have been put to practical use. In this case, a tool holder with a rotary joint for supplying a cutting oil is used except for those in which the tool does not rotate, such as a lathe. Various types of tool holders with rotary joints are commercially available.
Like a FLA type coolant flushing holder manufactured by Mizoguchi Iron Works, a housing that is rotatably provided via a plurality of bearings at the center of a tool holder integrated with a tapered shank. A rotary joint provided with a seal is configured so that the cutting oil fed from the supply port on the housing side is spouted from the tip of the drill with an oil hole mounted on the tool holder without leaking.

[0003]

The coolant flushing holder for metal working described in the prior art requires a strength sufficient to withstand high cutting resistance and a sealing structure for preventing leakage of cutting oil, so that it is relatively rotating. Since the diameter of the joint is large and a seal is used in which the lip contacts the outer periphery of the shaft of the tool holder, most of them are not suitable for dry high-speed rotation due to frictional heat and wear. Therefore, a tool with a rotary joint used to blow out gas such as air from the tool tip so that no chips remain in the machined hole as in woodworking and similar boring, for example, boring represented by a dowel joint. As a holder, there is a problem that it is too large for a woodworking machine such as a multi-axis boring shaft having a small center-to-center distance and cannot be used in terms of the number of rotations used. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a small-sized woodworking machine that can be applied to a multi-shaft boring shaft with a narrow shaft interval and can withstand dry high-speed rotation. It is an object of the present invention to provide a rotary joint for supplying gas such as air to a tool with a small hole.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, a rotary joint for woodworking according to the present invention comprises a woodwork having a fine hole in the axial direction and air jetted from a cutting edge such as a working drill or end mill or the like. A rotary joint for high-speed rotation for supplying gas, a through-hole having a tool grip at its tip, opening at the back of a tool mounting hole of the tool grip, and opening at the other end to the outer periphery of the shaft, and having a rear end. A rotating shaft having a mounting portion to a rotating shaft such as a boring shaft of a woodworking machine, and a plurality of end face shield type bearings fitted at positions on both sides which do not block the shaft outer peripheral opening of the through hole of the rotating shaft. A housing having a supply port for introducing gas such as air from a pressure source into the opening , and a housing fitted with the bearing at both ends with the supply port interposed therebetween; Perform the action. Further, the tool holder at the tip of the rotating shaft may be configured such that the tool holder unit can be detachably mounted.
Further, the end face shield type bearing can be replaced with an oil-free flat bearing such as an oil-impregnated metal.

[0005]

The gas such as air sent from the supply port into the housing of the rotary joint slightly leaks from the small gap of the bearing or the lubricated flat bearing to prevent chips generated by woodwork from entering the rotary bearing. Most of the gas such as air is ejected from the cutting edge through the through hole of the rotating shaft during high-speed rotation, passes through the small hole of the tool, and is blown away so that chips generated during machining do not remain in the machining hole.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIG. At the rear end there is provided a screw shaft 2a which is not loosened by the rotation of the boring shaft screwed into the screw hole at the end of the rotating shaft such as the boring shaft 1 of a woodworking machine, and has a tool holding portion having a tool mounting hole 2b at the tip. The shaft 2 is provided with a through-hole formed of an axial hole 2c having a stop at the end of the tool mounting hole 2b and a through-hole 2d communicating with the axial hole 2c at a substantially right angle near the stop. I have. The straight shank portion of the woodworking cone T is removably inserted into the tool mounting hole 2b at the tip of the rotating shaft 2,
The woodworking cone T is provided with a narrow hole Ta for air that branches into two at the tip, and the woodworking cone T is fixed by two fixing bolts 3.

Inner rings of end-face shield type bearings 4A and 4B are fitted to both sides of the rotary shaft 2 which do not block the through hole 2d. As the bearings 4A and 4B, commercially available bearings such as a ball bearing with a flange can be used.
The outer ring is fitted into the large-diameter hole at both ends of the housing 5 via the collar 6, and the axial position is regulated by a stepped end surface 2 f of the rotating shaft 2 and a nut 7 screwed into the screw portion 2 a at the rear end. The center hole of the collar 6 is formed to have a slightly larger hole diameter than the outer periphery of the rotating shaft, and does not contact the outer periphery of the rotating shaft 2.

A screw hole 5a is formed substantially in the center radial direction of the housing 5, and an air supply port 8 is screwed into the screw hole 5a. The housing 5 is prevented from rotating by a support (not shown), and the air fed from the air supply pipe leaks slightly from the gap between the bearings 4A and 4B, but the through hole 2d of the rotating shaft 2 almost rotated at high speed by the boring shaft 1 , Through the hole 2c in the axial direction, through the small hole Ta of the woodworking cone T, and is ejected from the cutting edge.

Next, a second embodiment will be described with reference to FIG. The same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The rotating shaft 12 has a hexagonal flange portion 12b integrally, and a screw shaft 12a screwed into a screw hole of the boring shaft 1 of the woodworking machine is engraved on the rear side of the rotating shaft 12 so as not to be loosened by the rotation of the boring shaft 1, A screw hole 12c for attaching a tool holder is formed at the end of the right shaft portion concentrically.
c is the same size as the screw hole at the tip of the boring shaft. A tapped axial hole 12d is formed in the depth of the screw hole 12c, and a through hole 12e communicating with the axial hole 12d at right angles is formed near the tapped portion. Oilless flat bearings 13A and 13B, such as oil-impregnated metal, are rotatably fitted to both sides of the rotary shaft 12 that do not block the through-holes 12e.
A and 13B are hexagonal flange 12b end face and snap ring 14
Regulates the axial position.

A one-touch tool holder unit 15 is detachably screwed into a screw hole 12c of the rotary shaft 12, and a large-diameter center for inserting an inner sleeve 18 into a holder body 16 of the tool holder unit. A hole 16a and a small-diameter center hole 16c through which air passes are formed.
A tapered groove 16b whose bottom is widened in the middle of the axis 6a in the axial direction is cut. Further, a screw shaft 17 attached to the rotating shaft 12 is formed integrally with the holder main body 16, and the screw shaft 17 is cut without any loosening in the rotation direction of the rotating shaft 12. The inner sleeve 18 has a flange and a trunk 18a.
A notch 18b, which does not interfere when the inner pins 18 move in the axial direction, is cut into a straight pin 19 described later in a direction perpendicular to the central axis.

Further, a through ball seat 18c having a small diameter on the inside and a sphere 21 looking through a hole is formed at a trisection point of the circumference of the position of the body portion 18a with respect to the tapered groove 16b.
A compression spring 22 that urges the inner sleeve 18 arbitrarily is interposed in the center hole 16a. Further, the holder body 16 has a straight pin 19 engraved with a screw (not shown) at the end in a direction perpendicular to the central axis at a position where it engages with the rotating torque receiving surface Tb of the woodworking cone T over the tapered groove 16b and the notch groove 18b. A pin hole is formed in which a female screw for screwing the threaded portion is cut into the bottom of the tapered groove.

The woodworking cone T inserted into the tool holder unit 15 has a small hole Ta, and a rotary torque receiving surface Tb with which the straight pin 19 contacts is cut in the axial direction. In order to mount the woodworking cone T on the holder body 16, the inner sleeve 18 is pushed in against the force of the spring 22, and the rotation torque receiving surface Tb of the woodworking cone T is inserted in phase so as to coincide with the straight pin 19. Then, when the woodworking cone T is pushed in until the rear end thereof comes into contact with the bottom of the hole and released from the inner sleeve 18, the inner sleeve 18 is pushed out by the force of the spring 22,
The sphere 21 located at the ball seat 18c holds the shank of the woodworking cone T by the force received from the wall surface of the tapered groove 16b. Also, when removing the woodworking cone T from the holder body 16, the inner sleeve 18 is pushed away from the wall surface of the tapered groove 16b, so that the holding force of the sphere 21 is released and the sphere 21 can be removed.

The rotary shaft 12 of the second embodiment has a hexagonal flange 12b.
Has the advantage that the mounting accuracy when mounting to a rotating shaft such as a boring shaft 1 of a woodworking machine is improved. Note that the tool holder unit is not limited to the one-touch type tool holder unit 15, and it goes without saying that all tool holder units such as a collet type tool holder unit and a fixing bolt type tool holder unit can be applied. . Further, the non-lubricated plain bearings 13A and 13B are also applicable as the bearings of the rotary shaft 2 integrated with the tool holding part of the first embodiment, and the bearings 4A and 4B are used as the bearings of the rotary shaft 12 of the second embodiment. Of course, it is also applicable. The through hole is open at the back of the tool mounting hole 2b and the other end is open at the outer periphery of the shaft. It is also possible to additionally provide a sealing member inside the two bearings, but in this case, it is necessary that the lip slightly touches the rotating surface under the supply air pressure.

[0014]

[Effects of the Invention] The present invention is configured as described above and has the following effects. The bearing of the rotary joint for air supply to be ejected from the cutting edge of the tool is a shielded end bearing or a non-lubricated plain bearing, and the sealing action of the bearing itself is used, so a slight gas leak from the bearing part during woodworking As a means to prevent dust from entering the rotary joint, it improves the life of the bearing, and because it has a simple structure, it is small and lightweight, so that it can be used for woodworking machines with narrow inter-axis distances such as multi-axis boring shafts. This makes it possible to blow off chips remaining in the machined hole, particularly in the case of small-diameter drilling in woodworking, and it is not necessary to remove the chips at the time of work, which is effective in forming a work line.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a woodworking rotary joint according to a first embodiment.

FIG. 2 is a cross-sectional view of a woodworking rotary joint according to a second embodiment.

[Explanation of symbols]

2, 12 Rotary shaft 2c Axial hole 2d Through hole 3 Tightening bolt 4A, 4B Bearing 5 Housing 12c Screw hole 13A, 1
3B Flat bearing 15 Tool holder unit 16 Holder body 17 Screw shaft 18 Inner sleeve 19 Straight pin 21 Sphere T Woodworking drill Ta Small hole

Claims (3)

(57) [Scope of request for utility model registration] 1. A woodwork having an axially fine hole and the like
A rotary joint for high-speed rotation that supplies gas such as air ejected from a cutting edge such as a machining drill or an end mill, the tool having a tool grip at its tip, and opened to the back of a tool mounting hole of the tool grip and the other end. There is a through-hole that is opened in the outer periphery of the shaft, a rotating shaft having a mounting portion to a rotating shaft such as a boring shaft of a woodworking machine at the rear end, and both sides of the through-hole of the rotating shaft that do not block the shaft outer peripheral opening. A plurality of end face shield type bearings fitted at positions, and a supply port for introducing a gas such as air from a pressure source into the opening , the bearings being provided at both ends with the supply port interposed therebetween. A rotary joint for woodworking, comprising: a fitted housing; and the bearing itself performs a sealing action of gas such as air. 2. A tool holding portion at a tip end of a rotary shaft in which a tool holder unit can be detachably mounted.
The described rotary joint for woodwork. 3. The rotary joint for woodworking according to claim 1, wherein said end face shield type bearing is replaced by an oil-free metal or other oil-free flat bearing.