JP2007307689A - Spindle device for machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle device for a machine tool, which prevents the attachment of oil mist to the inner wall face of a fluid supply pipe disposed in a through-hole of a spindle member, allows the sufficient amount of oil mist to reach an inner sleeve and a working tool without reducing the flowing amount of the oil mist, while suppressing vibration and deflection generated in the fluid supply pipe and preventing breakage of the inner sleeve, a draw bar and the like. <P>SOLUTION: The fluid supply pipe 24 is rotatably supported to the spindle member 10 with bearing members 25 and 26. When executing a prescribed work to a workpiece 40, the rotating speed of the fluid supply pipe 24 for supplying the fluid for use in lubrication and cooling to the inner sleeve 22 and the working tool 27 is set less than the rotating speed of a spindle member 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spindle device of a machine tool.

  In recent years, a spindle device 200 of a machine tool as shown in FIG. 3 has been widely used. The spindle device 200 of the machine tool includes a spindle member 10 and a drive motor 12 that rotationally drives the spindle member 10 in a hollow cylindrical housing 11 (see, for example, Patent Document 1).

  Bearing members 13 and 14 are disposed on the outer frame near the front end 10a and the outer frame near the rear end 10b of the main shaft member 10, and the main shaft member 10 is rotatable via the bearing members 13 and 14. It is supported by the housing 11 so as to be. The spindle member 10 is provided with a mounting hole 16 for mounting a tool holder 15 provided with a processing tool (cutting tool) 27 for performing desired processing on the workpiece 40 at the distal end portion 10a. A through hole 21 penetrating from the mounting hole 16 to the rear end portion 10b is formed.

  In the through hole 21, a fluid supply pipe 24 that supplies fluid used for lubrication and cooling when machining the workpiece 40 toward the tool holder 15 and the cutting tool 27 is disposed. The fluid supply pipe 24 has a front end 24 a inserted in an inner sleeve 22 provided inside the draw bar 17, and a rear end 24 b connected to a supply device 29 via an attachment member 30.

As the fluid for lubrication and cooling when machining the workpiece 40, a fluid (oil mist) made by mixing a minute amount of viscous cutting oil into high-pressure air is used. When processing the workpiece 40, the mist is supplied from the rear end portion 24b of the fluid supply pipe 24 from the supply device 29, flows through the fluid supply pipe 24, passes through the front end portion 24a, the inner sleeve 22, and the tool holder 15 or the like. The cutting tool 27 is reached.
JP 2002-172539 A

However, according to the invention disclosed in Patent Document 1, when the main shaft member 10 rotates (when the workpiece 40 is processed), the fluid supply pipe 24 also rotates together with the main shaft member 10. At this time, when the oil mist flows in the fluid supply pipe 24, the oil mist is affected by the centrifugal force generated with the rotation of the fluid supply pipe 24 and adheres to the inner wall surface of the fluid supply pipe 24 during the flow. Sometimes. Then, the flow amount of the oil mist decreases, and there is a problem that a sufficient amount of oil mist cannot reach the inner sleeve 22 (tool holder 15). Moreover,
Further, as the fluid supply pipe 24 rotates, vibration or deflection may occur in the fluid supply pipe 24. Then, the front end portion 24a of the fluid supply pipe 24 may come into contact with the inner sleeve 22, the draw bar 17, etc., and the fluid supply pipe 24, the inner sleeve 22, the draw bar 17, etc. may be damaged.

  Accordingly, the present invention has been made in view of the above-described problems, and the object thereof is to provide a fluid disposed in a through hole of the spindle member when machining the workpiece (when the spindle member rotates). The oil mist can be prevented from adhering to the inner wall surface of the supply pipe, and a sufficient amount of oil mist can reach the inner sleeve (tool holder) without reducing the flow rate of the oil mist. An object of the present invention is to provide a spindle device for a machine tool that can suppress vibrations, deflections, and the like, and can prevent damage to a fluid supply pipe, an inner sleeve, a draw bar, and the like.

  In order to solve the above-mentioned problem, a spindle device of a machine tool according to claim 1 is provided with a spindle device of a machine tool in which a machining tool for performing predetermined machining on a workpiece is mounted on a spindle member, and the machining tool is driven to rotate. In the spindle member, a through hole is formed along the rotation axis of the spindle device, and the spindle member is inserted into the through hole. A fluid supply pipe for supplying fluid, a bearing member provided between the spindle device and the fluid supply pipe, and rotatably supporting the fluid supply pipe with respect to the spindle member, and both ends of the fluid supply pipe are connected to the spindle device. A fluid supply when performing predetermined processing, comprising a seal member connected to the rotating portion and provided at the connecting portion and having a rotation damping function for attenuating the rotation of the spindle device and transmitting it to the fluid supply pipe The number of rotations of the pipe is the rotation of the main shaft member. Characterized in that less than.

  According to the first aspect of the present invention, when machining a workpiece (when the spindle device is rotating), the number of rotations of the fluid supply pipe can be significantly less than the number of rotations of the spindle member.

  Thereby, the oil mist (fluid for lubricating cooling) in the fluid supply pipe is not easily affected by the centrifugal force generated with the rotation of the fluid supply pipe, and is difficult to adhere to the inner wall surface of the fluid supply pipe. Therefore, a sufficient amount of oil mist can reach the processing tool without reducing the flow amount of oil mist. Furthermore, since the fluid supply pipe is rotatably supported with respect to the main shaft member by the bearing member, vibration and deflection generated in the fluid supply pipe are suppressed, and damage to the fluid supply pipe, the inner sleeve, the draw bar, and the like is prevented. be able to. A labyrinth seal structure is preferable as the structure of the seal member having a rotation attenuation function for attenuating the rotation of the main shaft device and transmitting it to the fluid supply pipe.

  The spindle device of the machine tool according to claim 3 is the spindle device of the machine tool according to claim 1 or 2, wherein the fluid supply pipe has a weight attached to an outer frame thereof, and the weight balance is biased. Features. According to the third aspect of the present invention, if the weight is attached to the lower side of the outer frame of the fluid supply pipe, the center of gravity of the fluid supply pipe is located below the axis. Thereby, even if it is a case where the rotation direction of a main shaft member is changed to an opposite direction in a short time, the rotation speed of a fluid supply pipe | tube can be made smaller than the rotation speed of a main shaft member.

  The spindle device of the machine tool according to claim 4 is the spindle device of the machine tool according to claim 1 or 2, wherein the fluid supply pipe has a flow path through which a fluid for lubricating cooling flows from an axis of the fluid supply pipe. It is formed unevenly, and the weight balance is uneven. According to the fourth aspect of the present invention, if the fluid supply pipe is installed so that the thick part is on the lower side, the center of gravity of the fluid supply pipe is below the axis. Thereby, even if it is a case where the rotation direction of a main shaft member is changed to an opposite direction in a short time, the rotation speed of a fluid supply pipe | tube can be made smaller than the rotation speed of a main shaft member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or is equivalent, and the description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a schematic cross-sectional view of a spindle device 100 of a machine tool and a tool holder 15 as a processing tool according to a first embodiment of the present invention. First, the tool holder 15 will be described. Although FIG. 1 shows the one-surface constrained tool holder 15, as a so-called two-surface constrained tool holder in which the flange portion 15a of the tool holder 15 contacts the end surface (tip portion 10a) of the main shaft member 10. Also good.

  The tool holder 15 is equipped with a cutting tool 27 for machining the workpiece 40 at one end and a pull stud 19 fixed to the tool holder 15 at the other end. A cavity along the axis AA is formed inside the pull stud 19, the tool holder 15, and the cutting tool 27, and a fluid pipe 28 in which oil mist as a fluid for lubricating cooling flows is formed in the cavity. Has been placed. Both end portions of the flow tube 28 are connected to the cutting tool 27 and the pull stud 19 via a seal member that attenuates the rotation of the tool holder 15 and transmits it to the flow tube 28.

  When machining the workpiece 40, oil mist supplied by a supply device 29 described later flows through the fluid supply pipe 24 and the flow pipe 28 and reaches the cutting tool 27, so that lubrication cooling at the time of machining is performed. Done. Therefore, it is desirable that a sufficient amount of oil mist reaches the cutting tool 27.

  Next, the spindle device 100 of the machine tool according to the present embodiment capable of causing a sufficient amount of oil mist to reach the cutting tool 27 will be described. A spindle device 100 of a machine tool is a built-in type in which a spindle member 10 and a drive motor 12 (12a, 12b) for rotating the spindle member 10 are housed in a hollow cylindrical housing 11.

  Bearing members 13 and 14 are disposed between the housing 11 and the main shaft member 10 in the vicinity of the front end portion 10a and the rear end portion 10b of the main shaft member 10, and the main shaft member 10 is accommodated by the bearing members 13 and 14 in the housing. 11 is supported so as to be freely rotatable. The drive motor 12 is disposed at a substantially intermediate portion between the bearing members 13 and 14, and is constituted by a rotor 12a disposed on the main shaft member 10 side (inner side) and a stator 12b disposed on the housing 11 side (outer side). Has been.

  The spindle member 10 has a mounting hole 16 for inserting and mounting a tool holder 15 provided with a processing tool (cutting tool) 27 for processing the workpiece 40 at the distal end portion 10a. A through hole 21 is formed so as to penetrate from the rear end portion 10b to the rear end portion 10b.

  In the through hole 21, a draw bar 17 having a known structure is disposed so as to be able to advance and retract in the through direction of the through hole 21. A collet chuck 20 for sandwiching the pull stud 19 when the tool holder 15 is mounted in the mounting hole 16 is disposed at the tip of the draw bar 17. The collet chuck 20 can be opened and closed as the draw bar 17 moves forward and backward by the action of the spring 18. After the collet chuck 20 sandwiches the pull stud 19, the tool holder 15 is pulled into the mounting hole 16 via the draw bar 17 by a driving mechanism (for example, a hydraulic cylinder device) (not shown), whereby the tool holder 15 is moved to the main shaft member 10. Retained.

  In addition, a metal (for example, iron) fluid supply pipe 24 that supplies fluid (oil mist) used for lubrication and cooling when machining the workpiece 40 toward the tool holder 15 is provided in the through hole 21. The front end 24a of the fluid supply tube 24 is connected to the inner sleeve 22 and supported by a bearing member 25 disposed between the main shaft member 10 and the fluid supply tube 24. The rear end 24 b of the supply pipe 24 is connected to the attachment member 30 and supported by a bearing member 26 disposed on the attachment member 30.

  A supply device 29 is connected to the attachment member 30 to supply oil mist that is atomized by mixing a small amount of viscous cutting oil into high-pressure air. The oil mist supplied by the supply device 29 flows through the fluid supply pipe 24 through the rotary joint 23 that does not rotate with the main shaft member 10 and the attachment member 30.

  Here, when processing the workpiece 40, when the main shaft member 10 rotates, the inner sleeve 22 and the attachment member 30 rotate together with the main shaft member 10, but at the connection portions of both ends 24 a and 24 b of the fluid supply pipe 24. Since the seal member that attenuates the rotation of the main shaft member 10 and transmits it to the fluid supply pipe 24 is disposed, the rotation speed of the fluid supply pipe 24 is less than the rotation speed of the main shaft member 10. As the seal member having a rotational damping function, for example, a labyrinth seal that is a non-contact type seal having a well-known structure can be used. As a result, the main shaft member 10 rotates at a rotational speed of several thousand revolutions per minute, whereas the rotational speed of the fluid supply pipe 24 can be about several to ten and several revolutions per minute.

  Therefore, according to the spindle device 100 for a machine tool according to the present embodiment, the oil mist flowing in the fluid supply pipe 24 is not easily affected by the centrifugal force. It becomes difficult for mist to adhere, and a sufficient amount of oil mist reaches the inner sleeve 22 (tool holder 15) without decreasing the flow amount of oil mist.

  The contact surface 41 between the inner sleeve 22 and the pull stud 19 is sealed with an unillustrated elastic body or metal packing, and the oil mist that has reached the inner sleeve 22 flows through the tool holder 15 without leaking. It is fed into the tube 28. The oil mist sent to the flow pipe 28 is discharged toward the workpiece 40 from a discharge path (not shown) by the centrifugal force generated with the rotation of the cutting tool 27 and the action of the high-pressure air of the supply device 29. As a result, lubrication cooling is performed when the workpiece is machined with oil mist.

  Furthermore, according to the spindle device 100 for a machine tool according to the present embodiment, the fluid supply pipe 24 is supported by the front end portion 24a and the rear end portion 24b by the bearing members 25 and 26. The generated vibration and deflection can be suppressed, and damage to the fluid supply pipe 24, the inner sleeve 22, the draw bar 17, and the like can be prevented.

(Other embodiments)
Another embodiment of the present invention will be described with reference to FIG. FIG. 2A is a drawing showing a schematic cross section of a spindle device 110 of a machine tool according to another embodiment of the present invention. FIG. 2B is a cross-sectional view of a state in which a weight 51 is arranged on the lower side of the fluid supply pipe 24 in the drawing. FIG. 2C is a cross-sectional view of the fluid supply pipe 54.

(Part 1)
The spindle member 10 constituting the spindle device 110 of the machine tool can rotate in both the left and right directions, and the rotation direction of the spindle member 10 may be changed to the opposite direction in a short time depending on the setting of machining conditions for the workpiece 40 and the like. However, even in such a case, it is desirable that the number of rotations of the fluid supply pipe 24 is smaller than the number of rotations of the main shaft member 10 in order not to reduce the flow rate of the oil mist. Furthermore, the fluid supply pipe 24 is preferably non-rotating.

  Therefore, when the machine tool in which the spindle device 110 according to this embodiment is incorporated is a horizontal type (horizontal type), a weight 51 is attached to the lower side of the outer frame of the fluid supply pipe 24 as shown in FIG. For example, the weight balance of the fluid supply pipe 24 is biased, and the center of gravity of the fluid supply pipe 24 is located below the axis. According to the inventor's knowledge, this makes it possible to reduce the rotational speed of the fluid supply pipe 24 relative to the rotational speed of the main shaft member 10. Furthermore, by adjusting the weight of the weight 51, the fluid supply pipe 24 can be made non-rotating regardless of the rotation of the spindle device 10.

  In this embodiment, as shown in FIG. 2B, the weight 51 is mounted in the vicinity of the center of the fluid supply pipe 24. However, the position where the weight 51 is mounted is not limited to this, and the weight 51 Even if 51 is mounted at a desired position, the same effect can be obtained.

(Part 2)
Instead of attaching the weight 51 to the lower side of the outer frame of the fluid supply pipe 24, the fluid supply pipe 54 in which the flow path 55 through which the oil mist flows is formed so as to be offset from the axial center can also be used. Also, the rotational speed of the fluid supply pipe 54 can be reduced.

  That is, the fluid supply pipe 54 is formed so as to be offset from the axial center as in the fluid supply pipe 54 whose cross section is shown in FIG. Is formed. If the fluid supply pipe 54 is installed in the through hole 21 so that the thick part 52 is on the lower side, the weight balance of the fluid supply pipe 54 is biased, and the center of gravity of the fluid supply pipe 54 is the axial center. Will be below. According to the inventor's knowledge, this makes it possible to reduce the rotational speed of the fluid supply pipe 54 compared to the rotational speed of the spindle device 10. Furthermore, by adjusting the position of the flow path 55, the fluid supply pipe 54 can be made non-rotating regardless of the rotation of the spindle device 10.

  Although the best mode for carrying out the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. is there.

  In the invention according to the dependent claims of the present invention, a part of the constituent features of the dependent claims can be omitted.

It is a figure which shows the schematic cross section of the spindle apparatus of the machine tool which concerns on the 1st Embodiment of this invention. (A) is a figure which shows the schematic cross section of the spindle apparatus of the machine tool which concerns on other embodiment of this invention, (b) and (c) are used suitably for the spindle apparatus of the machine tool which concerns on other embodiment. It is sectional drawing of the fluid supply pipe | tube used. It is a figure which shows the schematic cross section of the spindle apparatus of the conventional machine tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Main shaft member, 11 ... Housing, 12 ... Drive motor, 13, 14, 25, 26 ... Bearing member, 15 ... Tool, 16 ... Mounting hole, 17 ... Drawbar, 18 ... Spring, 19 ... Pull stud, 20 ... Collet chuck, 21 ... Through hole, 22 ... Inner sleeve, 23 ... Rotary joint, 24, 54 ... Fluid Supply pipe, 27 ... cutting tool, 28 ... cavity, 29 ... supply device, 30 ... mounting member, 51 ... weight, 55 ... flow path

Claims (4)

A spindle device of a machine tool in which a processing tool for performing predetermined processing on a workpiece is mounted on a spindle member, and the processing tool is driven to rotate,
A through hole is formed in the main shaft member along the rotation axis of the main shaft device, and the main shaft member is inserted into the through hole. When the processing tool performs a predetermined processing, a fluid for lubricating and cooling the processing tool. A fluid supply pipe for supplying
A bearing member provided between the spindle device and the fluid supply pipe, and rotatably supporting the fluid supply pipe with respect to the spindle member;
Both ends of the fluid supply pipe are connected to a rotating portion of the main shaft device, and a seal provided at the connecting portion has a rotational damping function for attenuating the rotation of the main shaft device and transmitting the attenuated rotation to the fluid supply tube. With members,
A spindle device for a machine tool, wherein the rotation speed of the fluid supply pipe when performing the predetermined machining is less than the rotation speed of the spindle member.   The spindle device for a machine tool according to claim 1, wherein the seal member has a labyrinth seal structure. The fluid supply pipe is
The spindle device for a machine tool according to claim 1 or 2, wherein a weight is attached to the outer peripheral portion and the weight balance is biased. The fluid supply pipe is
The main shaft of the machine tool according to claim 1 or 2, wherein a flow path through which the fluid for lubricating cooling flows is formed offset from an axial center of the fluid supply pipe, and the weight balance is uneven. apparatus.

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