JP5735299B2 - Spindle device - Google Patents

Description

  The present invention relates to a spindle device.

  Patent Document 1 discloses a conventional spindle device. The spindle device includes a spindle body that is rotatably supported in a housing, and a tool holder that is attached to the tip of the spindle body and rotates together with the spindle body. This tool holder incorporates an ultrasonic transducer. The tool holder is provided with a socket terminal to be inserted into a power terminal provided on the spindle body. The ultrasonic vibrator can vibrate by being supplied with power from the socket terminal via the power line.

  In this spindle device, the tool holder can be mounted on the spindle body using an automatic tool changer. For this reason, this spindle device can perform ultrasonic vibration-assisted processing without changing the basic structure of the existing spindle device.

Japanese Patent Laid-Open No. 5-208349

  However, since the spindle device of Patent Document 1 incorporates an ultrasonic vibrator in the tool holder, the ultrasonic vibrator must be incorporated in all of the tool holders to be replaced. Moreover, since the ultrasonic vibrator is incorporated, the tool holder becomes large and expensive. Furthermore, when the tool holder is mounted on the tip of the spindle body, the socket terminal provided on the tool holder must be inserted into the power terminal provided on the spindle body. At this time, if the connection between the socket terminal and the power terminal is not made well, the power supply to the ultrasonic vibrator becomes unstable, and the ultrasonic vibrator does not vibrate well and the ultrasonic vibration assisted processing is good. There is a risk that it may not be possible.

  The present invention has been made in view of the above-described conventional situation, and can be easily applied to existing machine tools, and automatically performs various types of processing well with the aid of ultrasonic vibration. It is an issue to be solved to provide a spindle device that can be used.

The spindle device of the present invention includes a spindle main body rotatably supported in a housing,
A horn part incorporating an ultrasonic transducer, a fixed part formed in a disk shape fixed to the front end surface of the spindle body, a side wall part formed in a cylindrical shape extending from the outer periphery of the fixed part toward the front end, connecting portion for connecting the node portion in the axial direction of the vibration of the sidewall portion the horn section, and around the horn portion, the fixed portion, the sidewall portion, and has a cavity formed in the connecting portion A spindle tip provided on the tip side of the spindle body and rotating together with the spindle body;
A tool holder mounted on the tip side of the spindle tip and rotating together with the spindle body and the spindle tip;
It is provided with a draw bar which is inserted into the spindle core of the spindle body and the spindle core of the tip of the spindle and clamps and unclamps the tool holder.

  This spindle device has a horn portion incorporating an ultrasonic transducer at the tip of the spindle, and can transmit ultrasonic vibration to a tool holder attached to the tip of the spindle tip. For this reason, it is not necessary to incorporate an ultrasonic transducer for each tool holder, and ultrasonic vibration-assisted processing can be performed using a general tool holder. That is, since it is not necessary to make the tool holder special, many tool holders for replacement can be easily prepared. Further, since the tool holder does not increase in size, it can be easily applied to existing machine tools. In particular, ultrasonic vibration cutting / grinding using an ultra-fine tool generally has a large number of processed holes, and thus the tool needs to be frequently replaced. For this reason, this spindle device can perform fine machining efficiently by applying it to a machine tool with an automatic tool changer.

  In addition, since the ultrasonic vibrator is incorporated in the horn portion, it is not necessary to connect a power supply path to the ultrasonic vibrator every time the tool holder is replaced. For this reason, the power supply to the ultrasonic transducer is stable, and the ultrasonic transducer can be vibrated satisfactorily and ultrasonic vibration-assisted processing can be performed satisfactorily. Further, since the hollow portion is formed around the horn portion, it is possible to easily dissipate heat generated from the ultrasonic vibrator, and it is possible to prevent performance degradation due to the high temperature of the ultrasonic vibrator.

  Therefore, the spindle device of the present invention can be easily applied to existing machine tools, and can automatically perform various types of processing satisfactorily with the aid of ultrasonic vibration.

  The spindle tip may have a communication hole that communicates the cavity with the outside. In this case, the heat generated from the ultrasonic transducer can be discharged to the outside through the through hole. For this reason, it is possible to further dissipate the heat generated from the ultrasonic vibrator, and therefore it is possible to further prevent performance degradation due to the high temperature of the ultrasonic vibrator.

The drawbar is
An engaging portion for engaging the tool holder, and an elastic member for applying an elastic force in a clamping direction, and a first bar extending rearward from the spindle tip portion;
The first bar may have a rear end portion and a second bar which are arranged coaxially with a gap and can push the first bar in the unclamping direction against the elastic force of the elastic member. .

  In this case, the vibration of the ultrasonic vibrator is not transmitted to the second bar. For this reason, vibration from the ultrasonic transducer is not transmitted to the drive unit that drives the second bar, and damage to the drive unit can be prevented.

It is a principal part schematic sectional drawing which shows the clamp state of the main axis | shaft apparatus of an Example. It is a principal part schematic sectional drawing which shows the unclamped state of the spindle apparatus of an Example.

  An embodiment embodying a spindle device of the present invention will be described with reference to the drawings.

<Example>
As shown in FIG. 1, the spindle device of the embodiment includes a spindle body 10, a spindle tip 20, a tool holder 30, and a draw bar 40. The spindle body 10 is formed in a cylindrical shape and has a through hole 12 that penetrates the shaft core. The spindle body 10 is rotatably supported in the housing 11 via an air bearing (not shown). The spindle body 10 is connected to a driving device (not shown), and rotates by driving the driving device. Further, the spindle body 10 has a non-contact power feeding device (not shown) arranged at the rear end. Power can be supplied to an ultrasonic transducer 25 described later via a power line C connected to a non-contact power supply device.

  The spindle tip portion 20 has a horn portion 21 and an outer shell portion 22 that forms a hollow portion 23 around the horn portion 21. The horn portion 21 includes a rear portion formed in a columnar shape and a front portion formed in a truncated cone shape that narrows toward the tip direction (downward in FIG. 1), and has a through hole 24 that penetrates the shaft core. ing.

  The horn part 21 has an ultrasonic transducer 25 formed in an annular shape on the outer periphery of the rear part. The ultrasonic transducer 25 is fixed to the outer peripheral portion of the rear portion of the horn portion 21 by a fixing ring 26. The horn portion 21 has a fitting hole 29 for fitting the fitting portion 31 of the tool holder 30 at the tip portion. The fitting hole 29 communicates with the through hole 24.

  The outer shell portion 22 has a fixing portion 22A, a side wall portion 22B, and a connecting portion 22C. The fixed portion 22A is formed in a disc shape and has a through hole 27 penetrating the center portion. The fixing portion 22 </ b> A is bolted to the front end surface of the spindle body 10 so as to be concentric with the spindle body 10. The side wall portion 22B is formed in a cylindrical shape extending in the distal direction (downward in FIG. 1) from the outer peripheral portion of the distal end surface of the fixed portion 22A. The side wall portion 22B has communication holes 28 that communicate the cavity portion 23 with the outside at a plurality of locations on the fixed portion 22A side. The connecting portion 22 </ b> C connects the side wall portion 22 </ b> B and the front side surface of the horn portion 21. The connecting portion 22C is formed at a node portion of axial vibration generated by the ultrasonic transducer 25. For this reason, 22 C of connection parts can be favorably fixed to the front end surface of side wall part 22B with a volt | bolt. The fixing portion 22 </ b> A, the side wall portion 22 </ b> B, and the connecting portion 22 </ b> C constituting the outer shell portion 22 form a hollow portion 23 around the horn portion 21.

  The tool holder 30 has a substantially cylindrical fitting portion 31 that fits into the fitting hole 29 of the horn portion 21. The fitting part 31 is formed in a convex shape on the inner peripheral surface, and has a locked part that engages with a locking part of a collet described later. The tool holder 30 has an end mill, a drill, an electrodeposition wheel tool, and the like for ultrafine machining attached to the tip by shrink fitting.

  The draw bar 40 has a first bar 40A and a second bar 40B. The first bar 40A includes an engaging portion 41 that engages the tool holder 30, and a coil spring 42 that is an elastic member that applies an elastic force in the clamping direction (upward in FIG. 1). The first bar 40A penetrates through the through hole 24 and the fitting hole 29 that penetrate the shaft core of the horn part 21 of the spindle tip 20 and the center part of the fixing part 22A of the outer shell part 22 of the spindle tip 20. It is inserted into the hole 27 and extends from the spindle tip 20 into the through hole 12 that passes through the shaft core of the rear spindle body 10.

  The engaging portion 41 has a sleeve 43 connected to the tip of the first bar 40 </ b> A and a collet 44 disposed on the outer peripheral side of the sleeve 43. The collet 44 has a locking portion that engages with a locked portion formed in a convex shape on the inner peripheral surface of the fitting portion 31 of the tool holder 30 on the outer peripheral surface on the distal end side.

  The coil spring 42 is inserted between the first bar 40 </ b> A and is sandwiched between a rear end surface of the horn portion 21 and a diameter-expanded portion 45 that is enlarged at the rear portion of the first bar 40. For this reason, the elastic force of the coil spring 42 is given so that the 1st bar | burr 40A may move back (upward in FIG. 1). As described above, when the first bar 40A is moved rearward, the locking portion of the collet 44 and the locked portion of the tool holder 30 are engaged, and the tool holder 30 is fixed to the spindle tip portion 20. It will be in a clamped state. That is, the coil spring 42 imparts an elastic force so as to move the first bar 40A in the clamping direction.

  The second bar 40B is disposed with a gap between the front end 40D and the rear end 40C of the first bar 40A. The second bar 40 </ b> B is coaxial with the first bar 40 </ b> A and is disposed in the through hole 12 that penetrates the axis of the spindle body 10. The distal end portion 40D of the second bar 40B is formed to be recessed in a conical shape. On the other hand, the rear end portion 40C of the first bar 40A is formed to protrude in a conical shape.

  The second bar 40B is connected to a drive unit (not shown) at the rear end, and can move in the distal direction (downward in FIG. 1) by driving the drive unit. When this drive unit is driven and the second bar 40B moves in the distal direction, the second bar 40B pushes the first bar 40A in the distal direction against the elastic force of the coil spring 42 as shown in FIG. become. When the first bar 40A is moved in the distal direction, the engagement between the locking portion of the collet 44 and the locked portion of the tool holder 30 is released, and the tool holder 30 is detachable from the spindle distal end portion 20. It becomes an unclamped state. That is, when the drive unit is driven, the second bar 40B pushes the first bar 40A in the unclamping direction. At this time, the tip 40D of the second bar 40B recessed in the conical shape and the rear end 40C of the first bar 40A projecting in the conical shape are fitted, so the second bar 40B unclamps the first bar 40A. It can push well in the direction.

  The spindle device configured in this way has a horn portion 21 incorporating an ultrasonic transducer 25 at the spindle tip 20 and transmits ultrasonic vibrations to a tool holder 30 mounted on the tip of the spindle tip 20. Can do. For this reason, it is not necessary to incorporate an ultrasonic transducer for each tool holder 30, and ultrasonic vibration-assisted processing can be performed using a general tool holder. That is, since it is not necessary to make the tool holder 30 special, many tool holders 30 for replacement can be easily prepared. Moreover, since the tool holder 30 does not increase in size, it can be easily applied to an existing machine tool with an automatic tool changer. In particular, the ultra-fine tool ultrasonic vibration cutting / grinding process generally has a large number of processed holes, so that it is necessary to change the tool frequently. For this reason, this spindle device can perform fine machining efficiently by applying it to a machine tool with an automatic tool changer.

  Further, since the ultrasonic transducer 25 is incorporated in the horn unit 21, it is not necessary to connect a power supply path to the ultrasonic transducer every time the tool holder 30 is replaced. For this reason, the power supply to the ultrasonic transducer 25 is stable, and the ultrasonic transducer 25 can vibrate well, and ultrasonic vibration-assisted processing can be performed satisfactorily. Further, since the cavity portion 23 is formed around the horn portion 21 and has a plurality of communication holes 28 for communicating the cavity portion 23 with the outside, the heat generated from the ultrasonic transducer 25 is dissipated. It is easy to prevent performance degradation caused by the ultrasonic transducer becoming hot.

  Therefore, the spindle device of the embodiment can be easily applied to an existing machine tool, and can automatically perform various types of processing satisfactorily with the aid of ultrasonic vibration.

  In addition, since the second bar 40B has a gap between the front end portion 40D and the rear end portion 40C of the first bar 40A, vibration from the ultrasonic transducer is generated in the drive unit that drives the second bar 40B. Without being transmitted, damage to the drive unit can be prevented.

The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the embodiment, the spindle tip portion has the communication hole that communicates the cavity and the outside, but the communication hole may not be provided.
(2) In the embodiment, the draw bar is divided into the first bar and the second bar. However, the draw bar may not be divided.
(3) In the embodiment, the end mill is attached to the tool holder, but various processing tools can be attached.
(4) In the embodiment, the processing tool is attached to the tool holder by shrink fitting, but may be attached by a method other than shrink fitting.
(5) In the embodiment, the spindle body is supported by the housing via the air bearing, but various bearings constituted by ball bearings or the like may be used.

  INDUSTRIAL APPLICABILITY The present invention can be used for a machine tool for ultrasonic vibration assisted machining with an automatic tool changer.

DESCRIPTION OF SYMBOLS 10 ... Spindle main body 11 ... Housing 20 ... Spindle front-end | tip part 21 ... Horn part
22A ... fixed part
22B ... Side wall
22C ... Connecting part 23 ... Cavity part 25 ... Ultrasonic vibrator 28 ... Communication hole 30 ... Tool holder 40 ... Draw bar 40A ... First bar 40B ... Second bar 41 ... Engagement part 42 ... Coil spring (elastic member)

Claims (3)

A spindle body rotatably supported in the housing;
A horn part incorporating an ultrasonic transducer, a fixed part formed in a disk shape fixed to the front end surface of the spindle body, a side wall part formed in a cylindrical shape extending from the outer periphery of the fixed part toward the front end, connecting portion for connecting the node portion in the axial direction of the vibration of the sidewall portion the horn section, and around the horn portion, the fixed portion, the sidewall portion, and has a cavity formed in the connecting portion A spindle tip provided on the tip side of the spindle body and rotating together with the spindle body;
A tool holder mounted on the tip side of the spindle tip and rotating together with the spindle body and the spindle tip;
A spindle apparatus comprising: a draw bar which is inserted into an axis of the spindle main body and an axis of the spindle tip and clamps and unclamps the tool holder.   2. The spindle device according to claim 1, wherein the spindle tip has a communication hole for communicating the cavity with the outside. The drawbar is
An engaging portion for engaging the tool holder, and an elastic member for applying an elastic force in a clamping direction, and a first bar extending rearward from the spindle tip portion;
A second bar that is disposed coaxially with a rear end portion of the first bar and that can be pushed in the unclamping direction against the elastic force of the elastic member; 3. The spindle apparatus according to claim 1, wherein the spindle device is provided.

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