JP3944375B2 - Tools, tool holders and machine tools - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tool for machining a workpiece mounted on a spindle of a machine tool, a tool holder for holding a processing tool such as an end mill, and a machine tool on which the tool or the tool holder is attached to and detached from the spindle.
[0002]
[Prior art]
For example, in a machine tool equipped with a spindle such as a machining center, the maximum rotation speed (per unit time) of the spindle is determined by the structure of the main bearing that holds the spindle rotatably and the lubrication method. For example, a speed increasing device is used to rotate the tool at a high rotational speed.
As the speed increasing device, for example, a device that holds a tool and can be attached to and detached from the main shaft, and increases the rotational speed of the tool by increasing the rotational force of the main shaft by a gear mechanism such as a planetary gear mechanism is known. ing.
For example, in a machining center, when it is desired to temporarily increase the rotational speed of the tool beyond the maximum rotational speed of the main shaft, the speed increasing device as described above is mounted on the main shaft in the same manner as a normal tool, Is rotating at a high speed.
[0003]
[Problems to be solved by the invention]
By the way, when the tool is increased from the rotational speed of the main shaft by the speed increasing device using the gear mechanism as described above, if the tool is rotated at an ultra high speed of several tens of thousands to several hundred thousand, the heat generation of the speed increasing device increases. , Machining accuracy may be affected by thermal expansion of the tool. In addition, at ultra high speed rotation of several tens of thousands to several hundred thousand rotations, noise from the speed increasing device also increases. Furthermore, since the speed increasing device has a highly reliable structure that can withstand, for example, tens of thousands to hundreds of thousands of rotations, there is a disadvantage that the manufacturing cost is relatively increased.
Also, in the case of a speed increasing device using a gear mechanism, the gears and bearings need to be lubricated, and since the lubricating oil supply path and discharge path are provided in the speed increasing apparatus, the size of the apparatus increases and automatic replacement by an automatic tool changer There was also the disadvantage that it was difficult.
As another speed increasing method, there is a case where a high frequency motor is used as a motor for driving the tool, a driving current is supplied from a control device specially prepared for the high frequency motor, and the tool is rotated at a high speed. is there. However, in this method, since there is a cable for supplying electric power from the outside, it is difficult to perform automatic tool change in the same manner as a normal tool, and there is a disadvantage that the equipment cost is relatively high.
[0004]
The present invention has been made in view of the above-described problems, and an object thereof is to attach a detachable tool spindle to a machine tool in the same manner as a normal tool, and to supply a machine tool without supplying power from the outside. A tool, tool holder, and a machine equipped with these tools that can achieve a higher rotational speed than the main shaft, can be driven without being connected to an external power supply, etc., and can be automatically changed. To provide a machine.
[0005]
[Means for Solving the Problems]
A tool according to the present invention is a tool that is detachably attached to a main spindle of a machine tool, and includes a processing tool for processing a workpiece, a rotating shaft to which the processing tool is mounted, and the rotating shaft and a coupling. an output shaft connected, and a motor main body for rotatably supporting the output shaft via the second bearing, an electric motor for driving the processing tool, the rotational force from the spindle of a machine tool is Ru is transmitted input A generator having a shaft and a generator main body that supports the input shaft; and a generator that generates electric power for driving the electric motor; and a detachably attached to the main shaft, and the rotational force of the main shaft is applied to the input shaft . A mounting portion for transmitting, a first case member for rotatably holding the mounting portion via a first bearing, and a coupling means coupled to the first case member, the generator body and the motor body the non-rotatable relative to the non-rotating portion of the machine tool A second case member that is held by the second case member, and a third case member that is coupled to the second case member by fastening means and rotatably holds the rotating shaft via a third bearing, The mounting portion, the generator, the electric motor, and the rotating shaft are sequentially arranged along the longitudinal direction of the main shaft, and the first case member, the second case member, and the third case member are Sealed bearings are used which are arranged in order along the longitudinal direction of the main shaft and in which a lubricant is sealed in the first bearing, the second bearing, and the third bearing.
[0006]
Preferably, the first case member, the second case member and the third casing that is constructed by connecting together the casing member is engaged with the non-rotating portion of the machine tool, the rotation is regulated Is done .
[0007]
Preferably, the generator is an AC generator that supplies a voltage having a frequency corresponding to the rotational speed of the main shaft to the electric motor, and the electric motor is an induction motor that rotates at a rotational speed corresponding to the frequency.
[0008]
The tool holder of the present invention is a tool holder that can hold a processing tool for processing a workpiece and is detachably mounted on a main spindle of a machine tool body, and has a rotating shaft on which the processing tool is mounted, has a tool holding portion for holding a processing tool rotatably, an output shaft connected through said rotary shaft and the coupling, and a motor main body for rotatably supporting the output shaft via the second bearing, wherein a an electric motor for rotating the tool holding part, an input shaft rotational force Ru is transmitted from the machine tool spindle, and a generator body for supporting the input shaft to generate power for driving the electric motor A generator, a mounting portion that is detachably mounted on the main shaft, and that transmits the rotational force of the main shaft to the input shaft , and a first case member that rotatably holds the mounting portion via a first bearing And connected to the first case member by fastening means Is, the generator and the second case member for holding the body and the motor body non-rotatably relative to the non-rotating portion of the machine tool are connected by fastening means to the second case member, the rotating shaft A third case member that rotatably supports the third bearing, and the mounting portion, the generator, the electric motor, and the rotating shaft are sequentially arranged along the longitudinal direction of the main shaft. The first case member, the second case member, and the third case member are sequentially arranged along the longitudinal direction of the main shaft, and the first bearing, the second bearing, and the third case are arranged. A sealed bearing in which a lubricant is sealed is used.
[0009]
A machine tool according to the present invention includes a machine tool body including a spindle, drive means for driving the spindle, at least one control axis for changing the relative position of the spindle and the workpiece, and a processing tool for processing the workpiece. the has a rotation shaft processing tool is attached, the motor body rotatably supporting via a second bearing the output shaft and the output shaft are connected through the rotary shaft and the coupling, the processing tool an electric motor for driving a has a generator body of a rotational force for supporting the input shaft and the input shaft Ru is transmitted from the main shaft, a generator for generating electric power for driving the electric motor, detachably to said main shaft is mounted on a mounting portion for transmitting the rotating force of the main shaft to said input shaft, a first case member for rotatably holding said mounting portion via a first bearing, said first case member are connected by fastening means, the generator present And a second case member for holding the motor main body non-rotatably relative to the non-rotating portion of the machine tool body, wherein connected by fastening means to the second case member, a third bearing the rotary shaft A machine tool having a third case member rotatably held via a tool, and a control device that drives and controls the driving means and the control shaft according to a machining program, The mounting portion, the generator, the electric motor, and the rotating shaft are sequentially arranged along the longitudinal direction of the main shaft, and the first case member, the second case member, and the third case member are Sealed bearings are used which are arranged in order along the longitudinal direction of the main shaft and in which a lubricant is sealed in the first bearing, the second bearing, and the third bearing.
[0010]
In the present invention, a tool attached to and detached from the main shaft is provided with a generator and an electric motor. Electric power is generated using the rotational force of the main shaft, and the electric motor is driven by the generated electric power to rotate the processing tool. As a result, the tool can be driven without being connected to an external power source or the like, and automatic tool change is also possible.
As described above, the tool of the present invention is completely independent from the main shaft and the external device. Therefore, the lubrication of the bearing used in the tool of the present invention is performed by, for example, supplying the lubricant from the main shaft or the outside. If it does, the supply path and discharge path of a lubricant will be needed, and the merit of making the tool completely independent from the spindle and external equipment will be lost, and the tool will be enlarged.
Therefore, in the present invention, by using a sealed bearing that does not require replenishment of a lubricant for the rotating part of the tool, the tool can be completely independent from the spindle and external equipment, and can be reduced in size. Become.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a machining center as an example of a machine tool to which the present invention is applied. The machining center is a numerically controlled machine tool capable of so-called complex machining.
The machining center 1 includes a machine tool main body 2, a numerical control device (NC device) 250, and a programmable controller (PLC) 150.
In FIG. 1, the machine tool body 2 includes a cross rail 37 supported at both ends by a shaft of a portal column 38 so as to be movable, and a saddle 44 movably supported on the cross rail 37. A ram 45 is provided so as to be movable in the vertical direction (Z-axis direction).
[0012]
A screw portion (not shown) is formed in the saddle 44 through the inside of the cross rail 37 in the horizontal direction, and a feed shaft 41 having a screw portion formed on the outer periphery thereof is screwed to the saddle 44. A servo motor 19 is connected to one end of the feed shaft 41, and the feed shaft 41 is rotationally driven by the servo motor 19.
By the rotational drive of the feed shaft 41, the saddle 44 can be moved in the Y-axis direction, whereby the ram 45 is moved and positioned in the Y-axis direction.
[0013]
Further, the saddle 44 is formed with a screw portion (not shown) in the vertical direction, and a feed shaft 42 having a screw portion formed on the outer periphery thereof is screwed into the screw portion. A servo motor 20 is connected to the end of the feed shaft 42.
The feed shaft 42 is rotationally driven by the servo motor 20, whereby the ram 45 movably provided on the saddle 44 is moved and positioned in the Z-axis direction.
[0014]
A main shaft motor 31 is built in the ram 45, and the main shaft motor 31 rotationally drives a main shaft 46 held rotatably by the ram 45.
A tool T including a processing tool such as an end mill and a tool holder for holding the processing tool is attached to the tip of the main shaft 46, and the tool T is driven by the rotation of the main shaft 46.
Below the ram 45, a table 35 to which a workpiece to be processed is fixed is provided so as to be movable in the X-axis direction. A screw portion (not shown) is formed on the table 35, and a feed shaft (not shown) provided along the X-axis direction is screwed to the table 35, and the servo motor 18 is connected to the feed shaft (not shown). Yes.
The table 35 is moved and positioned in the X-axis direction by the rotational drive of the servo motor 18.
[0015]
The two portal columns 38 are each formed with a thread portion (not shown), and the cross rail 37 is moved up and down by rotationally driving a feed shaft 32a screwed to the cross column lift servo motor 32. To do.
An automatic tool changer (ATC) 39 automatically changes various tools T with respect to the main shaft 46.
The automatic tool changer 39 stores, for example, a tool T in which various processing tools such as an end mill and a drill are held by a tool holder in a magazine (not shown), and a tool change arm (not shown) is attached to the spindle 46. The necessary tool T is mounted on the main shaft 46 by a tool changing arm.
[0016]
The NC device 250 performs drive control of the servo motors 18, 19, 20 and the cross rail lifting / lowering servo motor 32.
Specifically, the NC device 250 performs position and speed control between the tool T and the workpiece by the servo motors 18, 19, 20 and 32 according to a workpiece machining procedure defined in advance by a machining program. Further, the NC device 250 controls the rotational speed of the main spindle 46 by decoding the rotational speed (rotational speed per unit time) of the main spindle motor 31 defined by the S code in the machining program, for example.
Further, the NC apparatus 250 performs automatic exchange of various tools T by decoding the operation of exchanging the tool T defined by the M code in the NC program, for example.
[0017]
PLC 150 is connected to NC device 250 and operation panel 200. The PLC 150 performs various sequence controls such as starting and stopping the machining center 1 and outputting a signal for turning on and off the display unit of the operation panel 200 according to a predetermined sequence program.
The PLC 150 is connected to a spindle motor driver 157 that drives and controls the spindle motor 31. The PLC 150 outputs a control command for starting, stopping, and speed control of the spindle motor 31 to the spindle motor driver 157. The PLC 150 performs various sequence controls.
[0018]
FIG. 2 is a cross-sectional view showing the configuration of an embodiment of the tool of the present invention.
In FIG. 2, the tool 60 includes a cutting tool 100 and a tool holder 61 that holds the cutting tool 100. The cutting tool 100 is an embodiment of the processing tool of the present invention. Further, the tool 60 according to the present embodiment is attached to and detached from the main shaft 46 by the automatic tool changer 39 in the same manner as the normal tool T described above.
[0019]
The tool holder 61 includes a mounting portion 62, a case 65 including case members 66, 67, and 68, a generator 70, an electric motor 80, a tool holding portion 90, and a rotation preventing member 85.
[0020]
The mounting portion 62 includes a gripping portion 62a to be gripped, a taper shank portion 62b to be mounted on the taper sleeve 46a formed on the tip portion of the main shaft 46, and a pull formed on the tip portion of the taper shank portion 62b. A stud 62c and a shaft 62d that is rotatably held by the case member 66 are provided.
[0021]
The gripping part 62a of the mounting part 62 is transported from the magazine of the automatic tool changer 39 to the spindle 46 by the tool changer arm of the automatic tool changer 39 and from the spindle 46 to the magazine of the automatic tool changer 39. It is gripped when it is done.
[0022]
The taper shank portion 62 b of the mounting portion 62 is mounted on the taper sleeve 46 a of the main shaft 46 so that the central axis is concentric with the central axis of the main shaft 46.
[0023]
When the mounting portion 62 is mounted on the tapered sleeve 46 a of the main shaft 46, the pull stud 62 c of the mounting portion 62 is clamped by a collet of a clamp mechanism (not shown) built in the main shaft 46. The clamping mechanism built in the main shaft 46 is a well-known technique and will not be described in detail.
[0024]
The shaft portion 62 d of the mounting portion 62 is rotatably held on the inner periphery of the case member 66 via a plurality of bearings 72. As the bearing 72, a sealed angular contact ball bearing is used as will be described later.
[0025]
A generator 70 and an electric motor 80 are held on the inner periphery of the case member 67 via a holding member 73.
In the generator 70, the input shaft 71 is concentrically connected to the shaft portion 62 d of the mounting portion 62, and the rotational force of the main shaft 46 is transmitted to the generator 70 via the mounting portion 62.
As the generator 70, for example, a three-phase synchronous generator is used.
[0026]
The electric motor 80 is supplied with electric power generated by the electric generator 70 through a conductive cable (not shown). The electric motor 80 is driven by electric power supplied from the generator 70.
As the electric motor 80, for example, a three-phase induction motor can be used.
[0027]
The tool holding unit 90 includes a rotating shaft 91, a coupling 93 that connects the rotating shaft 91 and the rotating shaft 81 of the electric motor 80, and a tool mounting member 95 fixed to the tip of the rotating shaft 91. The rotating shaft 91 and the rotating shaft 81 are an embodiment of the drive shaft of the present invention.
The rotating shaft 81 of the electric motor 80 is rotatably held by a bearing (not shown). A bearing (not shown) that supports the rotating shaft 81 of the electric motor 80 is also one of the bearings of the present invention. Further, a sealed angular contact ball bearing is used for this bearing, as will be described later.
[0028]
The rotating shaft 91 is rotatably held on the inner periphery of the case member 68 via a plurality of bearings 92. As the bearing 92, a sealed angular contact ball bearing is used as will be described later.
The distal end side of the rotation shaft 91 is prevented from being detached from the case member 68 by a retaining member 94.
[0029]
The cutting tool 100 is held by a tool mounting portion 95, and the cutting tool 100 processes a workpiece. The tool mounting portion 95 is an embodiment of the tool holding portion of the present invention. The cutting tool 100 is specifically various kinds of cutting tools such as a drill and an end mill. Other processing tools include polishing, a grindstone, and the like.
[0030]
Case members 66, 67 and 68 are connected by fastening means such as bolts, for example, and these case members 66, 67 and 68 constitute case 65.
An anti-rotation member 85 is provided on the outer periphery of the case member 66.
When the mounting portion 62 is mounted on the taper sleeve 46a of the main shaft 46, the anti-rotation member 85 has a tip 85a in the fitting hole 47a formed in the non-rotating portion 47 such as the ram 45 on the main shaft 46 side. Inserted.
Thereby, the rotation of the case member 66, that is, the case 65 is restricted even if the main shaft 46 rotates.
[0031]
Sealed angular ball bearings are used as the bearing 72 of the shaft portion 62d, the bearing 92 of the rotating shaft 91, and the bearing of the rotating shaft 81 of the electric motor 80.
The above-mentioned sealed angular contact ball bearings are special products. Generally, sealed ball bearings are called cap bearings in JIS and ISO, and those of shield type, non-contact seal type, and contact seal type are known. Yes.
A sealed angular contact ball bearing 300 shown in FIG. 3 is of a contact seal type.
In FIG. 3, a plurality of balls 301 as rolling elements are arranged so as not to contact each other by a cage 340, and are arranged between the raceway groove 330 a of the inner ring 330 and the raceway groove 330 a of the outer ring 320. Annular seal members 310 and 311 are provided on both side surfaces of the inner ring 330 and the outer ring 320.
Grease G is enclosed in a space sealed by the seal members 310 and 311.
[0032]
As the grease G, it is preferable to use, for example, a grease that has as little frictional force as possible and that evenly distributes the grease G in the bearing over a long period of time even at high speed rotation so that the loss of the grease G is small. Specifically, the trade name alkanol L75 of FAG company etc. is mentioned.
[0033]
Next, an example of the operation of the tool 60 according to the present embodiment will be described.
First, the tool 60 holding the cutting tool 100 on the tool mounting portion 95 is mounted on the spindle 46 of the machine tool main body 2 by the automatic tool changer 39.
In the tool 60, the tip end portion 85a of the rotation preventing member 85 is fitted and inserted into the fitting hole 47a of the non-rotating portion 47, and the rotation of the case 65 is restricted.
[0034]
From this state, when the main shaft 46 is rotated at the rotation speed N ₀ , the mounting portion 62 of the tool 60 rotates and the rotational force of the main shaft 46 is transmitted to the generator 70.
Thereby, the generator 70 produces | generates three-phase alternating current power, when a three-phase synchronous generator is used, for example.
[0035]
The frequency f of the three-phase AC power generated by the three-phase synchronous generator is given by the following equation (1), where P ₁ is the number of poles of the three-phase synchronous generator and the rotational speed of the main shaft 46 is N ₀ [min ⁻¹ ]. ).
[0036]
[Expression 1]
_{f = P 1 × N 0/} 120 [Hz] ... (1)
[0037]
Therefore, when the main shaft 46 is rotated at the rotation speed N ₀ , the three-phase AC power having the frequency f expressed by the above equation (1) is supplied to the motor 80.
[0038]
Here, when using the electric motor 80 three-phase induction motor, the number of poles of the three-phase induction motor and P _2, a three-phase induction motor since the 2 / P ₂ rotate in one cycle of the three-phase AC, The synchronous speed N ₁ of the three-phase induction motor when there is no slip is expressed by the following equation (2).
[0039]
[Expression 2]
N ₁ = 120 × f / P ₂ [min ⁻¹ ] (2)
[0040]
Thus, the rotational speed N ₁ of the tool 60 with respect to the rotational speed N ₀ of the spindle 46 is represented by the following formula (3).
[0041]
[Equation 3]
N ₁ = N ₀ × P ₁ / P ₂ [min ⁻¹ ] (3)
[0042]
As can be seen from the equation (3), the rotational speed N ₀ of the main shaft 46 is shifted to the rotational speed N ₁ represented by the above formula (3).
As shown by the equation (3), by appropriately setting the ratio of the number of poles P ₁ of the three-phase synchronous generator and the number of poles P ₂ of the three-phase induction motor, the tool 60 with respect to the rotational speed N ₀ of the main shaft 46 is set. It can be seen that the speed ratio of the rotational speed N ₁ can be set arbitrarily.
That is, when it is desired to increase the rotational speed N ₀ of the main shaft 46, the pole number ratio P ₁ / P ₂ is made larger than 1, and when it is desired to decelerate, the pole number ratio P ₁ / P ₂ is made smaller than 1. Thus, the number of poles P ₁ of the three-phase synchronous generator and the number of poles P ₂ of the three-phase induction motor may be selected in advance.
[0043]
For example, assuming that the maximum rotational speed Nmax of the main spindle 46 is 3000 min ⁻¹ , in the machining of a workpiece using a normal tool, the rotational speed of the main spindle 46 is often sufficient within the range of the maximum rotational speed Nmax. .
On the other hand, when the machining center 1 having the maximum rotation speed Nmax of the spindle 46 of 3000 min ⁻¹ is used and, for example, an aluminum alloy material is used for the workpiece, and the high speed machining is desired, the rotation speed of the tool 60 is set to 30000 min ⁻ , for example. There are cases where you want to increase the speed to ¹ .
For such a case, the tool 60 is previously stored in the magazine of the automatic tool changer 39 of the machining center 1. The tool 60 incorporates a three-phase synchronous generator and a three-phase induction motor having the pole number ratio P ₁ / P ₂ of 10 so that the speed increasing ratio is 10.
[0044]
The automatic tool changer 39 automatically mounts the tool 60 on the spindle 46 in the same manner as a normal tool.
The main shaft 46 is rotated by driving the main shaft motor 31, and the rotational speed of the cutting tool 100 held by the tool 60 is controlled by the rotational speed of the main shaft 46. That is, in the NC program downloaded to the NC device 250, the rotation speed of the cutting tool 100 of the tool 60 is defined by designating the rotation speed of the main spindle 46 with an S code. That is, the NC device 250 controls the rotational speed of the cutting tool 100 of the tool 60 by controlling the rotational speed of the main shaft 46.
For example, when it is desired to rotate the cutting tool 100 of the tool 60 at 30000 min ⁻¹ , the number of rotations of the main shaft 46 is specified as 3000 min ⁻¹ with an S code in the NC program.
[0045]
When the main shaft 46 is rotated at 3000 min ⁻¹ , the generator 70 generates a three-phase alternating current having a frequency corresponding to the number of rotations of the main shaft 46 and the number of poles P ₁ .
The electric motor 80 is driven by the three-phase alternating current supplied from the generator 70, and the cutting tool 100 of the tool 60 rotates at a rotational speed of approximately 30000 min- ¹ .
[0046]
In the state where the cutting tool 100 is accelerated as described above, the work is cut by moving the work fixed to the table 35 and the cutting tool 100 (main shaft 46) in accordance with the machining program.
[0047]
Thereby, for example, when the machining center 1 in which the maximum number of rotations of the main shaft 46 is limited is used, the cutting tool 100 is rotated at a number of rotations exceeding the maximum number of rotations of the main shaft 46, thereby enabling high-speed machining of the workpiece.
[0048]
As described above, according to the present embodiment, the generator 70 and the electric motor 80 are built in the tool holder 61 that is unitized in the same way as a normal tool, and the electric motor 80 is driven by the electric power generated by the electric generator 70. In order to increase the rotational speed of the tool 60 with respect to the main shaft 46, even if the main shaft 46 is rotated at a high speed, heat generation does not increase as in the gear device, and thermal expansion of the tool 60 is suppressed, so that deterioration in machining accuracy is suppressed. Is done.
[0049]
Furthermore, according to this embodiment, since the inertia of the electric motor 80 can be made smaller than the inertia of the main shaft 46, the responsiveness of the cutting tool 100 can be improved as compared with the case where the main shaft 46 is directly rotated at a high speed.
[0050]
Further, according to the present embodiment, the tool 60 for increasing the rotational speed of the main shaft 46 can be attached to and detached from the main shaft 46 and can be replaced by the automatic tool changer 39 in the same manner as a normal tool. Therefore, it is possible to immediately respond to the demand for high-speed processing while performing processing within the range of the normal rotation speed.
Moreover, according to this embodiment, since the blade 100 is driven by the electric power generated by the rotation of the main shaft 46, it is not necessary to supply a driving current from the outside, and as a result, wiring for supplying power is not necessary.
[0051]
Furthermore, according to the present embodiment, by using a sealed angular contact ball bearing as the bearing used in the tool 60, it is not necessary to supply the lubricant from the outside of the tool 60, and the lubricant supply path and the discharge path are provided in the tool 60. There is no need to provide it inside. For this reason, the tool 60 can be reduced in size, and as a result, the tool 60 is suitable for automatic change by the automatic tool changer 39.
[0052]
【The invention's effect】
According to the present invention, it is possible to obtain a tool, a tool holder, and a machine tool including these that can obtain a higher rotational speed than the main spindle of the machine tool without supplying electric power from the outside.
Further, according to the present invention, it is detachably mounted on the spindle of the machine tool in the same manner as a normal tool, can be driven without being connected to an external power source, etc., and is miniaturized so that automatic tool change is possible. A tool, a tool holder, and a machine tool including these are obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a machining center as an example of a machine tool to which the present invention is applied.
FIG. 2 is a cross-sectional view showing the configuration of an embodiment of the tool of the present invention.
FIG. 3 is a cross-sectional view of an example of a sealed angular contact ball bearing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Machining center 2 ... Machine tool main body 31 ... Main shaft motor 39 ... Automatic tool changer 46 ... Main shaft 60 ... Tool 62 ... Mounting part 65 ... Case 66, 67, 68 ... Case member 70 ... Generator 80 ... Electric motor 90 ... Tool holding Part 95 ... Tool mounting part 100 ... Cutting tool 250 ... NC device 300 ... Sealed angular ball bearings 310, 311 ... Seal members

Claims (8)

A tool that is detachably attached to a spindle of a machine tool,
A processing tool for processing the workpiece;
A rotating shaft on which the processing tool is mounted;
An output shaft connected through said rotary shaft and the coupling, an electric motor and a motor main body for rotatably supporting the output shaft via the second bearing, for driving the processing tool,
A generator from said machine tool spindle and input shaft rotational force Ru is transmitted, and a generator body for supporting the input shaft to generate power for driving the electric motor,
A mounting portion that is detachably mounted on the main shaft, and that transmits a rotational force of the main shaft to the input shaft ;
A first case member that rotatably holds the mounting portion via a first bearing;
A second case member connected to the first case member by fastening means and holding the generator main body and the electric motor main body non-rotatably with respect to a non-rotating portion of the machine tool ;
A third case member connected to the second case member by fastening means, and rotatably holding the rotating shaft via a third bearing;
Have
The mounting portion, the generator, the electric motor, and the rotating shaft are sequentially arranged along the longitudinal direction of the main shaft,
The first case member, the second case member, and the third case member are sequentially disposed along the longitudinal direction of the main shaft,
A sealed bearing in which a lubricant is sealed is used for the first bearing, the second bearing, and the third bearing. The case configured by connecting the first case member, the second case member, and the third case member to each other engages with a non-rotating portion of the machine tool, and rotation is restricted. The tool according to 1. The generator is an AC generator that supplies a voltage with a frequency corresponding to the rotational speed of the main shaft to the motor.
The tool according to claim 1, wherein the electric motor is an induction motor that rotates at a rotation speed corresponding to the frequency. A tool holder that can hold a processing tool for processing a workpiece and is detachably attached to a spindle of a machine tool body,
A tool holding unit that has a rotating shaft on which the processing tool is mounted, and rotatably holds the processing tool;
An output shaft connected through said rotary shaft and the coupling, and a motor main body for rotatably supporting the output shaft via the second bearing, an electric motor for rotating the tool holder,
A generator from said machine tool spindle and input shaft rotational force Ru is transmitted, and a generator body for supporting the input shaft to generate power for driving the electric motor,
A mounting portion that is detachably mounted on the main shaft, and that transmits a rotational force of the main shaft to the input shaft ;
A first case member that rotatably holds the mounting portion via a first bearing;
A second case member connected to the first case member by fastening means and holding the generator main body and the electric motor main body non-rotatably with respect to a non-rotating portion of the machine tool ;
A third case member connected to the second case member by fastening means, and rotatably holding the rotating shaft via a third bearing;
Have
The mounting portion, the generator, the electric motor, and the rotating shaft are sequentially arranged along the longitudinal direction of the main shaft,
The first case member, the second case member, and the third case member are sequentially disposed along the longitudinal direction of the main shaft,
A tool holder in which a sealed bearing in which a lubricant is sealed is used for the first bearing, the second bearing, and the third bearing. The case configured by connecting the first case member, the second case member, and the third case member to each other engages with a non-rotating portion of the machine tool, and rotation is restricted. 4. The tool holder according to 4. The generator is an AC generator that supplies a voltage with a frequency corresponding to the rotational speed of the main shaft to the motor.
The tool holder according to claim 4, wherein the electric motor is an induction motor that rotates at a rotation speed corresponding to the frequency. A machine tool body comprising a main shaft, drive means for driving the main shaft, and at least one control shaft for changing the relative position of the main shaft and the workpiece;
A processing tool for processing a workpiece, and a rotary shaft, wherein the processing tool is attached, the motor main body for rotatably supporting the output shaft and the output shaft are connected through the rotary shaft and coupled via a second bearing has an electric motor for driving the processing tool has a generator body of a rotational force for supporting the input shaft and the input shaft Ru is transmitted from the main shaft, the generator for generating electric power for driving the electric motor A mounting portion that is detachably mounted on the main shaft, and that transmits a rotational force of the main shaft to the input shaft; and a first case member that rotatably holds the mounting portion via a first bearing; A second case member connected to the first case member by fastening means, and holding the generator main body and the electric motor main body non-rotatably with respect to a non-rotating part of the machine tool main body; and the second case member Connected to the case member by fastening means A tool with a third case member for rotatably holding said rotary shaft via a third bearing,
A machine tool having a control device for driving and controlling the driving means and the control shaft according to a machining program,
In the tool,
The mounting portion, the generator, the electric motor, and the rotating shaft are sequentially arranged along the longitudinal direction of the main shaft,
The first case member, the second case member, and the third case member are sequentially disposed along the longitudinal direction of the main shaft,
A sealed bearing in which a lubricant is sealed is used for the first bearing, the second bearing, and the third bearing. The machine tool according to claim 7, further comprising an automatic tool changer that attaches and detaches the tool to and from the spindle.

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