JP4771051B2 - Rotary joint for semi-dry machining - Google Patents

Description

  The present invention relates to a rotary joint for semi-dry processing for supplying oil mist to the tip of a processing tool when performing semi-dry processing with a spindle-through machine tool.

  In spindle-through machine tools that supply machining fluid from the tip of a rotating tool, there was no supply failure because a large amount of water-soluble machining fluid was conventionally supplied through a rotary joint at a high pressure. There has been a demand for semi-dry machining in through machine tools. Two methods are conceivable for semi-dry machining with the same mechanical structure. One is a method of generating mist before the rotary joint and introducing it into the rotary joint (for example, Patent Document 1). The second is to generate mist inside the rotary joint and rotary spindle.

The former example of generating mist before the rotary joint will be described with reference to FIG.
A rotary joint 21 is connected to a rotary shaft 20 of the machine tool via a rotary bearing 22 having a ball bearing. The rotary joint 21 is provided with an oil mist inlet 23 and an oil mist supply pipe 24 that communicates with the oil mist inlet 23 and is disposed along the axis of the rotary joint 21. The front end of the oil mist supply pipe 24 is in communication with the rear end of the rotary shaft 20, and the abutting surface 25 is a sliding surface.
When oil mist generated outside is introduced into the oil mist inlet 23, the oil mist moves from the oil mist inlet 23 through the oil mist supply pipe 24 and is further supplied into the rotary shaft 20 of the machine tool. The The oil mist supplied into the rotary shaft 20 is injected from a tool tip (not shown) through the main shaft of the machine tool.
Japanese Patent Laid-Open No. 11-320327 (FIG. 4 etc.)

  However, the former method of introducing pre-generated oil mist into the rotary joint has a problem that loss of oil mist is unavoidable due to the internal structure of the rotary joint, the level difference or bending of the pipe thread portion, and the like. To increase the oil mist transport efficiency, the latter method of generating mist inside the rotating spindle is advantageous. In this case, however, a dedicated structure is required and a new design is required. Get higher. In addition, the method of generating the inside of the rotary main shaft and the rotary joint has a problem that the size of the mist varies and the mist cannot be supplied to the processing point.

  The present invention has been made against the background described above, and relates to a semi-drying rotary joint that can generate fine oil mist in a rotary joint with a simple structure and efficiently transport it to a machine tool.

That is, the semi-dry machining rotary joint of the present invention is the invention according to claim 1, wherein the machining oil supply connection portion to which an external machining oil supply source is connected, and the gas supply connection portion to which an external gas supply source is connected. A processing oil supply passage communicating with the processing oil supply connection portion, a porous body connected to the processing oil supply passage and supplied with the processing oil from the processing oil supply passage, and communicating with the gas supply connection portion. the porous material gas supply path for supplying gas it mixed droplets of working oil is in contact with the surface of, and communication means for communicating the gas supply passage to the rotation axis shaft hole of the spindle of a machine tool through wherein the and rotary shaft and said communicating means is rotatable relative to abutting contact, it said porous body includes a feature that you have located over said rotary shaft shaft hole within the communicating means To do.

The invention of claim 2 semi-dry working rotary joint in that in the invention of claim 1, wherein said communicating means that the tip at least the distal end portion is positioned coaxially to the rotary shaft passed through with the rotating shaft rear end It consists of a communication cylinder, The cylinder hole of this communication cylinder is used as a gas supply path, or this cylinder hole is connected to the gas supply path, It is characterized by the above-mentioned.

The invention of the rotary joint for semi-dry processing according to claim 3 is the invention according to claim 1 or 2, wherein the processing oil supply pipe extends as a processing oil supply path, and a porous body is provided at the tip thereof. The gas supply path is configured by a gas supply pipe that extends from the rear to the front of the porous body and is coaxially positioned on the outer peripheral side of the processing oil supply pipe and extends forward .

  According to the present invention, an external processing oil supply source is connected to the processing oil supply connection portion, and the processing oil is supplied from the processing oil supply source to a processing oil supply path communicating with the processing oil supply connection portion. Further, an external gas supply source is connected to the gas supply connection portion, and gas is supplied from the gas supply source to a gas supply path communicating with the gas supply connection portion.

  The processing oil flows out to the surface through the porous body through the processing oil supply path to form microdroplets and a liquid film. The gas flowing through the gas supply path flows so as to contact the porous body. The effluent on the surface of the porous body is engulfed in this gas flow, and remains as microdroplets, or is further divided into microparticles and mixed into the gas. As a result, a stable minute processing oil mist can be obtained immediately in the rotary joint without generating processing oil droplets having a large particle diameter. This mist is injected and supplied to the rotating shaft shaft hole of the machine tool through the communication means, and is supplied to the machining point through the shaft hole of the machine tool.

The rotary joint of the present invention is connected to the rotation side of the machine tool via a rotary joint portion or the like. The structure of the rotary joint portion is not particularly limited as the present invention, and can be configured by a rotary bearing or the like. The present invention can be connected to the rotary side of the machine tool with the rotary joint as a stationary side. I just need it.
Further, the communication means is not particularly limited in the present invention, but as a simple configuration, there is one that abuts the front end of the communication cylinder with the rear end of the rotating shaft of the machine tool and seals the abutting surface as a sliding surface with an oil seal or the like. It is done. In this structure, the gas supply path through which the oil mist moves and the shaft hole of the rotating shaft can be communicated without requiring a complicated configuration. In addition, a communication means using a rotary joint or the like can be used. Note that the rotary joint of the present invention does not include a rotary shaft as a component. The rotating shaft has a shaft hole connected to the main shaft hole of the machine tool, and the structure thereof is not limited to a specific one.
The communication cylinder may be interposed between the gas supply path and the rotation shaft, or may be configured as a communication cylinder by a supply pipe or the like constituting the gas supply path. .

  In addition, the arrangement position of the porous body is not limited to a specific location in the present invention, but part or all of the porous body is preferably located in the rotation shaft shaft hole of the machine tool, and a part thereof is in the rotation shaft hole. When located, it is desirable to place the other part in the gas supply path. When at least a part of the porous body is located in the rotation shaft shaft hole, part or all of the oil mist generated around the porous body is generated in the shaft hole of the rotation shaft, and as the rotation shaft rotates. The oil mist is efficiently mixed in the swirl flow in accordance with the swirl flow generated in this way. In addition, when the rotating shaft and the communicating cylinder which is the communication means are communicated by butting, a part of the porous body is in the shaft hole of the rotating shaft, and the other part is in the communicating cylinder. Is desirable. The action of the porous body in the shaft hole of the rotating shaft is as described above, and the same action can be obtained in the porous body in the vicinity thereof. In addition, the porous body in the communicating cylinder can provide an oil seal action by supplying a part of the generated oil mist to the abutting surface. This oil seal maintains lubrication and keeps the joint between the rotating shaft and the communicating cylinder well without causing seizure even when oil mist is generated or when semi-dry machining is not performed. can do.

The porous body and the gas supply path through which the gas flow moves are arranged coaxially, and more stable mist generation is achieved by moving the gas flow along the peripheral liquid outflow surface of the porous body. It becomes possible. The porous body and the gas flow path may be positioned on either the inner peripheral side or the outer peripheral side, and the one positioned on the outer peripheral side may be arranged in a cylindrical shape. At this time, by making the cross-sectional area of the gas supply path around the porous body smaller than that on the gas supply side connecting portion side, the gas flow is increased and the mist is generated more smoothly.
Moreover, although air is normally provided as a gas which produces | generates mist, gas, such as nitrogen, oxygen, a carbon dioxide, can be used as needed, and it is not limited to specific gas as this invention.

  For the porous body used in the present invention, foam metal, foam ceramic, sintered filter, resin filter, metal fiber filter, or the like is used. However, the present invention is not limited to the porous material described above, and may be a porous material made of other materials. However, the porous body needs to be able to move the fluid supplied from the fluid supply path for liquid droplets to the liquid outflow surface of the outflow portion, and the movement of the liquid is achieved by having continuity in the porous body.

  In addition, the size and density of the pores formed in the porous body are not limited to specific ones, but the liquid for droplets flows out evenly on the liquid outflow surface to form sufficiently small droplets or liquid film You may decide to do. For example, the hole size may be 0.05 to 0.1 mm in terms of the equivalent circle diameter. When oil flows out from the pores of such a size as a liquid for droplets to form an oil film, it is expected to have a thickness of about 0.01 to 0.05 mm. This thickness is the thickness that is expected to be maintained by blowing the gas stream.

  The flow rate of the gas flow is not particularly limited as the present invention. There is no problem at a flow rate of about 800 to 1200 m / sec. The diaphragm further increases the speed, and for example, the speed can be increased to reach more than 1 to 10 times.

The processing oil droplets blown off from the porous body and mixed in the gas flow are considered to have a diameter of about 0.05 to 0.1 mm at the time of peeling from the pores of the above-mentioned size. In addition, it is expected to have a diameter of about 0.01 to 0.02 mm, which is about 1/5, by receiving a shearing force in a gas flow.
However, the above numerical values are merely examples, and it is needless to say that the present invention is not limited to a specific range.

  As described above, according to the rotary joint for semi-dry processing of the present invention as described above, a processing oil supply connection portion to which an external processing oil supply source is connected, a gas supply connection portion to which an external gas supply source is connected, A processing oil supply passage communicating with the processing oil supply connection portion, a porous body connected to the processing oil supply passage and supplied with the processing oil from the processing oil supply passage, and communicating with the gas supply connection portion; A gas supply path for supplying a gas mixed with droplets of processing oil in contact with the surface of the porous body, and a communication means for communicating the gas supply path with a rotation shaft shaft hole of a spindle-through machine tool; And a rotating joint portion connected in a stationary state to the rotating side of the machine tool, so that a mist having fine droplets is immediately generated near the porous body, and the axis of the machine tool is immediately generated without having a long path. Can be introduced into the hole Loss generates Rumisuto in a rotating joint efficiently send it to allow a good semi-dry process to little processing point. In addition, by using the joint, it is possible to effectively use a small amount of mist and contribute to improvement of machining accuracy and tool life.

Below, one Embodiment of this invention is described based on FIG.
The rotary joint 1 has a cavity 1a that opens to the front end on the front side, and the rotary shaft 2 of the machine tool having the shaft hole 2a is located in the cavity 1a. A rotary joint portion 3 using a ball bearing is provided on the inner peripheral surface on the front end side of the cavity 1a. The rotary joint portion 3 comes into contact with the outer peripheral surface of the rotary shaft 2 and the rotary joint 1 and the rotary shaft. 2 are connected. In addition, the contact part 2b with which the front end surface of this rotation joint part 3 contact | abuts is formed in the outer peripheral part of the rotating shaft 2, and the rotation joint part 3 is fixed in the position where the front-end | tip contacted the applicable contact part 2b. The side is fixed to the rotating shaft 2. The rotary shaft 2 can rotate with respect to the stationary rotary joint 1 via the rotary joint 3.

  In addition, a small-diameter cavity 1 b that continues to the cavity 1 a is formed on the rear side of the rotary joint 1 and opens at the rear end of the rotary joint 1. An air supply pipe 5 is slidably fitted as a gas supply path to the distal end side of the small diameter cavity 1b. The front end of the air supply pipe 5 can be butt-joined to the rear end of the rotary shaft 2, and the butt-joint with the rotary shaft 2 is made by adjusting the position by sliding with respect to the small-diameter cavity 1 b. . Note that the abutting surfaces of the rotating shaft 2 and the air supply pipe 5 are sliding surfaces, and each abutting surface 8 is made of ceramic and cemented carbide to prevent seizure. The abutting surface 8 can obtain an oil seal effect by permeation of oil mist described later. Moreover, the front-end | tip part of the air supply pipe 5 is formed in the large diameter, can hold | maintain the oil which oozed out to the front-end | tip surface, and can improve an oil seal effect.

Further, a machining oil supply block 6 having a through hole 6a is fitted into the rear opening of the small-diameter cavity 1b, and the machining oil supply block 6 serves as a machining oil supply connection portion as an external machining oil supply source (not shown). ) Can be connected. A processing oil supply pipe 7 having a pipe hole 7 a communicating with the through hole 6 a of the block 6 is connected to the tip of the processing oil supply block 6. The processing oil supply pipe 7 extends forward, is inserted into the pipe of the air supply pipe 5 so as to have a gap with the inner surface of the air supply pipe 5, and reaches a little rearward of the air supply pipe 5. The through hole 6a of the processing oil supply block 6 and the tube hole 7a of the processing oil supply pipe 7 constitute a processing oil supply path.
In addition, a cylindrical porous body 9 having an outer diameter substantially the same as the outer diameter of the processing oil supply pipe 7 is connected to the tip of the processing oil supply pipe 7. is about half a gap is formed between the position to the rotating shaft 2 shaft hole in the rotary shaft 2 of the. The gap between the processing oil supply pipe 7 and the air supply pipe 5 and the gap between the processing oil supply pipe 7 and the porous body 9 (hereinafter referred to as the gap 5a) constitute a part of the air supply path.

  Further, a side air supply hole 10 communicating with the small-diameter cavity 1b is formed on the rear side surface of the rotary joint 1 as a gas supply connection portion, and can be connected to a gas supply source such as external factory air. Yes. Therefore, the small-diameter cavity 1b connected to the side air supply hole 10 also constitutes a part of the gas supply path.

Next, the operation of supplying mist by the rotary joint 1 will be described.
A processing oil supply block, which is a processing oil supply connecting portion, such as a processing oil supply connecting portion, such as a processing oil supply pipe connected to a processing oil supply source (not shown), is connected to the side air supply hole 10. 6, air is supplied to the side air supply hole 10, and processing oil is supplied to the processing oil supply block 6 by pressure. In the machine tool, the rotary shaft 2 is rotated by the operation, and the rotary joint 1 is in a stationary state by the rotary joint portion 3.
The processing oil is supplied to the porous body 9 through the through hole 6 a of the processing oil supply block 6 and the tube hole 7 a of the processing oil supply pipe 7, and all of the porous body 9 is impregnated with the processing oil. The processing oil impregnated in the porous body 9 further reaches the outer surface of the porous body 9, and the oil that has flowed out of the surface pores becomes fine oil droplets or an oil film.

  On the other hand, the air introduced into the side air supply hole 10 moves through the gap 5a from the small-diameter cavity 1b. In addition, since this clearance gap 5a becomes a small cross-sectional area with respect to the small diameter cavity 1b, the air flow is accelerated. The air moving through the gap 5 a moves from the outer peripheral surface of the porous body 9 along the tip surface of the porous body 9 while being in contact with the porous body 9. As a result, fine oil droplets are effectively peeled from the surface of the porous body 9 one after another, and are entrained in the air to be misted. In the mist, fine droplets are stably generated, and then move to the tip side of the machine tool through the shaft hole 2a of the rotary shaft 2 of the machine tool. Since most of the oil mist is generated in the rotating shaft 2, minute oil droplets are smoothly mixed into the air flow accompanied by the rotating flow to be mist. The oil mist that moves through the shaft hole 2a is supplied from the tip of the machine tool to a machining point (not shown). As a result, good lubricity is provided, and semi-dry machining with a machine tool is performed well. The oil mist penetrates into the abutting surface 8 between the rotary shaft 2 and the air supply pipe 5 and oil-seals the sliding surface to surely prevent the seizure. The permeated oil is spread and held on the front end surface of the air supply pipe 5 as described above, and the lubricity in a state where no oil mist is generated can be ensured more reliably.

  Note that the oil mist generated and injected in the rotary joint as described above produces fine oil droplets stably, is stable without generating coarse oil droplets, and is accurate to the desired processing point. Is injected into. Since diffusion to an unnecessary area is suppressed, the effect of mist injection can be reliably obtained even with a small amount of mist.

  The present invention has been described based on the above embodiment. The present invention is not limited to the content of the above embodiment, and can be appropriately changed within the scope of the present invention.

It is sectional drawing which shows one Embodiment of this invention. It is sectional drawing which shows the conventional rotary joint for semi-dry processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating joint 1a Cavity 1b Small-diameter cavity 2 Rotating shaft 2a Shaft hole 3 Rotating joint part 5 Air supply pipe 5a Clearance 6 Processing oil supply block 6a Through hole 7 Processing oil supply pipe 7a Pipe hole 9 Porous body 10 Side air supply hole

Claims (3)

A processing oil supply connection portion to which an external processing oil supply source is connected, a gas supply connection portion to which an external gas supply source is connected, a processing oil supply path communicating with the processing oil supply connection portion, and the processing oil A porous body connected to the supply path and supplied with the processing oil from the processing oil supply path, and communicated with the gas supply connection portion, contacting the surface of the porous body and mixing a droplet of the processing oil A gas supply path for supplying gas; and a communication means for communicating the gas supply path with a rotation shaft shaft hole of a spindle-through machine tool , wherein the rotation shaft and the communication means are abutted and contacted so as to be relatively rotatable. cage, wherein the porous body is semi-dry working rotary joint, characterized that you have located over said rotary shaft shaft hole within the communicating means. Said communicating means comprises tip at least a tip portion is positioned coaxially to the rotary shaft from the cylindrical communicating member that passes with the rotary shaft rear end, the cylinder bore of the communicating cylindrical body with a gas supply passage, or the tubular The rotary joint for semi-dry machining according to claim 1, wherein the hole communicates with the gas supply path. A processing oil supply pipe extends as a processing oil supply path, and a porous body is provided at the tip thereof. The gas supply path is hung from the rear to the front of the porous body on the outer peripheral side of the processing oil supply pipe. The rotary joint for semi-dry processing according to claim 1, wherein the rotary joint is configured by a gas supply pipe that is coaxially positioned and extends forward .

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