JP2006187822A - Spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle device which does not damage the compactness thereof, achieves a high speed increasing/decreasing ratio, and exhibits an improved machining ability. <P>SOLUTION: The spindle device has a speed increasing/decreasing mechanism 5 arranged at a location between a spindle 4 with a chuck portion 3 for gripping a tool, on one end thereof, and an input shaft 2 with a shank portion, for increasing/decreasing the rotational speed of the spindle 4 with respect to the rotational speed of the input shaft 2. The speed increasing/decreasing mechanism 5 is of a rocking type, and comprised of a rotary body 12 which is rotatably borne by an inclined portion 10 formed on an outer peripheral surface or an inner peripheral surface of either the input shaft 2 or the spindle 4. The rotary body 12 is formed with a second gear A2 having n2 teeth engageable with a first gear A1 fixed to a spindle main body 1 and having n1 teeth, at an axial end thereof, and is formed with a third gear A3 having n3 teeth engageable with a fourth gear A4 formed on the input shaft or the spindle and having n4 teeth. Thus the rotary body performs rocking motion on the inclined portion and changes engaging locations between the respective gears. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spindle device, and more particularly to a high-performance spindle device that is used by being connected to a spindle of various machine tools and configured to drive a tool at high speed or high torque by the action of an acceleration / deceleration mechanism.

Conventionally, as a spindle device of this type, a planetary gear mechanism as a speed increasing mechanism is interposed between an input shaft connected to a machine main shaft and a spindle having a chuck portion for gripping a tool at a front end, and the planetary gear is provided. A spindle apparatus configured to increase the rotation speed of the input shaft by a mechanism and rotate the spindle at a high speed is known. (Patent Document 1)
JP-A-8-57734

  By the way, the spindle device described in Patent Document 1 can drive the tool at a high speed by the speed increasing action of the planetary gear mechanism, and can perform highly efficient machining. However, in recent years, there has been a demand for higher processing capabilities for milling machines, machining centers, and the like, and further improvement is required in Patent Document 1.

  That is, the planetary gear mechanism is generally composed of a sun gear, a pinion gear supported by a carrier, and a ring gear, and these gears are configured to mesh in the radial direction. In this method, the speed increase / decrease ratio is basically governed by the ratio of the number of teeth of the sun gear and the ring gear, that is, the ratio of the pitch circle. In order to obtain a high speed increase / decrease ratio, it is necessary to reduce the sun gear diameter and increase the ring gear diameter. is there. When the diameter of the sun gear is reduced, the shaft diameter of the spindle needs to be reduced, so that the rigidity of the spindle is lowered and the machining accuracy is affected. In order to maintain the rigidity of the spindle, it is necessary to enlarge the sun gear. However, in order to obtain a predetermined speed increase / decrease ratio, the diameter of the ring gear increases correspondingly, and the external dimensions of the spindle device increase, which is not practical. In order to secure the compactness and secure the necessary high speed increase / decrease ratio, it can be ensured by arranging a plurality of planetary gear mechanisms in the axial direction, but the structure becomes complicated and this is not practical.

  The present invention has been made paying attention to such a point, and provides a spindle device that can realize a higher acceleration / deceleration ratio and can greatly improve the machining capability without impairing the compactness of the spindle device. For that purpose.

  The means according to claim 1 of the present invention for solving the above-mentioned problem comprises an acceleration / deceleration mechanism between a spindle provided with a chuck portion for gripping a tool at one end and an input shaft, and prevents rotation of the input shaft. In the spindle apparatus configured to increase / decrease the rotation of the spindle, the acceleration / deceleration mechanism includes a rotating body rotatably supported on an inclined portion formed on an outer periphery or an inner periphery of either the input shaft or the spindle. A second gear having a number of teeth n2 meshing with a first gear having a number of teeth n1 fixed to the spindle body, and a fourth number n4 of teeth cooperating with the input shaft or the spindle. A third gear having the number of teeth n3 that meshes with the gear is formed, and is configured as a swing type acceleration / deceleration mechanism that changes the meshing position between the gears while the rotating body swings on the inclined portion. To do.

  The present invention is provided with a so-called oscillating acceleration / deceleration mechanism that performs acceleration / deceleration by oscillating motion of a rotating body supported on an inclined portion. By utilizing this, it is possible to ensure the compactness of the spindle device and to improve the machining capability by realizing a high speed reduction ratio. In other words, the oscillating type speed increasing / decreasing mechanism can obtain the maximum gear ratio when the gear ratio is the smallest when the difference in the number of teeth between the meshing gears is minimum. In addition, a high speed increase / decrease ratio can be obtained, and the radial dimension of the spindle device can be reduced. In addition, since the meshing position of each gear is in the axial direction of the spindle, the shaft center portion of each gear can be made hollow, and the linkage with the input shaft or spindle as a component of the spindle device is facilitated. In addition, since the shaft diameter of each shaft can be increased, particularly in the case of a spindle in which a tool chuck is attached to the tip, shaft rigidity can be increased, which contributes to improvement of machining accuracy.

  According to a second aspect of the present invention, in the first aspect, the rotating body is rotatably supported on an inclined portion formed on the spindle, and the input shaft is linked to the fourth gear. . According to this configuration, the speed increasing / decreasing mechanism is configured as a speed increasing mechanism, and the spindle functions as a high speed spindle. In this case, the speed increasing ratio can be set very large, so that the machining capability is greatly improved.

  According to a third aspect of the present invention, in the first aspect, the rotating body is rotatably supported on an inclined portion formed on the input shaft, and the spindle is linked to the fourth gear. . According to this configuration, the speed increasing / decreasing mechanism is configured as a speed reducing mechanism, and the spindle device functions as a high speed reducing spindle device. In this case, the reduction ratio can be set very large, and the machining capability of the high torque spindle device is greatly improved.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the speed increasing / decreasing mechanism is arranged in the axial direction between the input shaft and the spindle. According to this configuration, since the radial dimension can be kept small, the space efficiency can be improved even when a plurality of spindle devices are used together.

  According to a fifth aspect of the present invention, there is provided the means according to any one of the first to fourth aspects, wherein the speed reduction mechanism and the output shaft are each arranged in a separate spindle body and configured as an independent unit body. Is characterized in that the rotational force can be transmitted to each other. According to this configuration, it can be configured as a high-performance spindle device with high deceleration and high acceleration in combination with an existing spindle device that does not include an acceleration / deceleration mechanism.

  According to a sixth aspect of the present invention, in any one of the first to third aspects, the input shaft is configured as a cylindrical member, an acceleration / deceleration mechanism is disposed on an inner peripheral portion of the input shaft, and an electric motor is disposed on the outer peripheral portion. Is arranged. According to this configuration, the overall size can be reduced in a state where the power source unique to the spindle device is provided.

  According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the speed increasing / decreasing mechanism includes a switching mechanism for limiting the speed increasing / decreasing action. According to this configuration, the rotation speed of the spindle device can be switched according to the processing mode, so that the processing applications can be expanded.

  Since the spindle apparatus of the present invention is configured as described above, a higher acceleration / deceleration ratio can be obtained without impairing the compactness of the spindle apparatus, and the machining capability can be greatly improved.

  The first embodiment will be described below with reference to FIGS. 1 and 2, the spindle apparatus of the first embodiment includes an input shaft 2 in a spindle body 1, a spindle 4 having a chuck portion 3 for holding various tools at one end, and the input shaft 2 and the spindle 4. And an oscillating type acceleration / deceleration mechanism 5 that accelerates or decelerates the rotation of the input shaft 2.

  The spindle main body 1 is provided with a flange (not shown) as an attachment portion that is attached to the attachment portion of the machine tool in a non-rotatable manner at an axial end portion on the input shaft 2 side. The input shaft 2 is rotatably supported via a bearing 6 on the inner periphery of the spindle body 1. A dog clutch type shank portion 2a is formed at one end of the input shaft 2, and a fourth gear A4 constituting the speed increasing / decreasing device 5 is formed at the other end. The spindle 4 is rotatably supported at one end on the inner peripheral portion of the input shaft 2 via a bearing 7 and at the other end via a bearing 9 on the inner periphery of a hub 8 constituting a part of the spindle body 1. And is rotatably supported. The spindle 4 includes an inclined portion 10 constituting the acceleration / deceleration mechanism 5 between the bearings 7 and 9, and the inclined portion 10 has an axis Y inclined at a predetermined angle with respect to the axis X of the spindle 4. I have.

  The speed increasing / decreasing mechanism 5 includes a first gear A1 and a fourth gear A4 that are concentric with the input shaft 2 and spaced from each other at a predetermined distance, and a second gear that meshes with the first gear and the fourth gear, respectively. A gear A2 and a third gear A3 are provided. The first gear A <b> 1 is formed as a fixed bevel gear having a predetermined pitch cone on the open end surface of the hub 8 fixed to the spindle body 1. The fourth gear A4 is formed as a bevel gear having a predetermined pitch cone at one end of the large-diameter portion of the input shaft 2. The second and third gears A2 and A3 are axial directions of the rotating body 12 that is rotatably supported via the balls 11 on the inclined portion 10 located between the first gear A1 and the fourth gear A4. Are formed as bevel gears having a predetermined pitch cone on both end faces. In this embodiment, the meshing position of the first gear A1 and the second gear A2 has a phase difference of 180 degrees with respect to the meshing position of the third gear A3 and the fourth gear A4.

  Rollers 13 are interposed in the meshing portion between the first gear A1 and the second gear A2 and the meshing portion between the third gear A3 and the fourth gear A4. As shown in FIG. 2, the tooth profile of each gear is formed in a concave shape that fits the roller 13. The rollers are arranged on the first gear A1 and fourth gear A4 side, the first and fourth gears are configured as convex teeth with the rollers 13 located in the recesses, and the second and third gears are It is configured as a concave tooth that meshes with the convex tooth.

  The speed increasing / decreasing mechanism of the present embodiment is connected to the input shaft 2 and the spindle 4 so that the rotation of the input shaft 2 is transmitted to the inclined portion 10 via the fourth gear A4 and the rotating body 12, respectively. Although it is configured as a mechanism, if this connection state is reversed, it becomes a speed reduction mechanism. That is, an inclined portion that supports the rotating body 12 is formed on the input shaft, and the spindle can be linked to the fourth gear to constitute a speed reduction mechanism.

  Hereinafter, the operating principle of the acceleration / deceleration mechanism will be described in detail. For convenience of explanation, a case will be described in which the speed increasing / decreasing mechanism is configured as a speed reducing mechanism in which the fourth gear is linked to the output side (spindle side) and the inclined portion side is the input side.

That is, the rotating body 12 performs a swinging motion with respect to the rotation of the inclined portion 10, and the second gear A2 and the third gear A3 formed on the end surfaces thereof are moved with respect to the axis of the first gear A1 and the fourth gear A4. Thus, the first and second gears and the third and fourth gears are displaced in the circumferential direction.
At this time, the circumferential relative displacement between the first gear A1 and the second gear A2 is only a value corresponding to the number of teeth difference between the first gear A1 and the second gear A2, that is, if the number of teeth difference is 1. One tooth is displaced with respect to the surface swing motion of one cycle of the rotating body. When the difference in the number of teeth is 2, two teeth are displaced. The same movement is performed between the third gear A3 and the fourth gear A4. Therefore, when the speed reduction mechanism is configured, if the speed reduction ratio is R (the rotation speed of the output shaft (spindle) when the input shaft rotates once),
R = 1− (n1 × n3) / (n2 × n4).

  Where n1 is the number of teeth of the first gear A1, n2 is the number of teeth of the second gear A2, n3 is the number of teeth of the third gear A3, n4 is the number of teeth of the fourth gear A4, and n1 = 99, n2 = When 100, n3 = 101, and n4 = 100, the reduction ratio is R = 1 / 10,000 (forward rotation).

  That is, since the number of teeth of the first gear A1 is 99 and the number of teeth of the second gear A2 is 100, when the input shaft 2 rotates forward once, the second gear A2 is 1/100 of the first gear A1. Only forward rotation. The movement of the second gear A2 is directly transmitted to the third gear A3, and the same meshing is performed between the third gear A3 and the fourth gear A4. In this case, if the number of teeth of the third gear A3 is 101 and the number of teeth of the fourth gear A4 is 100, the fourth gear A4 rotates backward by 1/100 with respect to the third gear A3. Therefore, one-stage deceleration is also performed between the third gear A3 and the fourth gear A4. That is, when the rotational movement of the input shaft 2 is transmitted to the output side, two-stage deceleration is performed between the first and second gears A1 and A2 and between the third and fourth gears A3 and A4. Will be done.

  In order to configure the speed reduction mechanism that performs the speed reduction action based on the above principle as the speed increase mechanism, as shown in FIG. 1, the fourth gear side is set as the input shaft 2 and the inclined portion as shown in FIG. This can be realized by using the 10 side as an output. In this case, the speed increasing ratio R is expressed by R = 1 / [1- (n1 × n3) / (n2 × n4)]. If the number of teeth of the first to fourth gears is n1 = 99, n2 = 100, n3 = 100, and n4 = 100, the speed increasing ratio R = 100 times. In this case, since the third gear A3 and the fourth gear A4 have the same number of teeth, the speed increasing action is not performed between them, and the first speed increasing action between the first gear A1 and the second gear A2 Become.

  Since the spindle device of the first embodiment is configured as described above, when the input shaft 2 is driven by the rotation of the spindle of the machine tool, the speed is increased or decreased by the speed increasing / decreasing mechanism 5 and transmitted to the spindle 4. The tool gripped by the tip chuck portion 3 is driven.

  At this time, when the speed increasing / decreasing mechanism 5 is configured as a speed increasing mechanism, the speed increasing speed is increased to an ultra-high speed state with respect to the rotation of the main shaft, for example, machining using a drill having a small diameter of 0.2 to 0.3 mm or less This is particularly effective in grinding using a grindstone. Further, when configured as a speed reduction mechanism, the torque of the main shaft is greatly amplified, which is particularly effective in processing using, for example, a large milling cutter or a large-diameter drill.

  Therefore, this embodiment has the following features.

  First, the spindle device according to the present embodiment has an oscillating acceleration / deceleration mechanism 5 that has fewer components and a large acceleration / deceleration ratio compared to a conventional planetary gear type acceleration / deceleration mechanism. Since it is arranged coaxially with the shaft 2 and the spindle 4, it is possible to reduce the size of the spindle device and to improve the performance of the spindle device by increasing the speed or torque. Further, since the gears are meshed with each other at the end face in the axial direction of each gear, the radially inner sides of the first to fourth gears A1 to A4 can be formed hollow. The shaft diameter can be increased, and sufficient shaft rigidity can be secured to improve machining accuracy. If the shaft diameter can be increased, it can be sufficiently secured as a coolant passage for the tool, and the effect is extremely great.

  In addition, since the spindle device of the present embodiment can ensure a high increase / decrease ratio by meshing gears with a small difference in the number of teeth, the ratio of the number of simultaneously meshed teeth to the total number of teeth is large, and the force applied to the teeth is small. Since the torque is reduced and the transmission torque is increased, not only the performance as a spindle device is improved, but also the durability reliability as the spindle device can be improved.

  Next, a second embodiment shown in FIG. 3 will be described. The same parts as those in the first embodiment and corresponding parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  The spindle device of the second embodiment shown in FIG. 3 is composed of two units, a first unit and a second unit, each unit having a first spindle body 1a and a second spindle body 1b, respectively. Both units are configured such that transmission of power can be interrupted as necessary. The first unit includes an input shaft 2, an acceleration / deceleration mechanism 5, and a first spindle 4a constituting a part of the spindle 4 in the first spindle body 1a. The second unit is disposed in the second spindle body 1b. A second spindle 4b having a chuck portion 3 for gripping a tool at one end is rotatably supported. A dog clutch 17 is formed at the other end of the second spindle 4b so as to be able to be connected to and disconnected from the first spindle 4a.

  Therefore, in the spindle device of the second embodiment, the speed increasing / decreasing mechanism 5 and the second spindle having the chuck portion 3 are configured as separate units. It can be used as a functional spindle device.

  Next, a third embodiment shown in FIG. 4 will be described. The spindle device of the third embodiment shown in FIG. 4 is composed of two detachable units as in the second embodiment. The first unit includes an electric motor 14, an input shaft 2 as a cylindrical member, an acceleration / deceleration mechanism 5 having a switching mechanism 15 for intermittently increasing / decreasing action, and a first spindle 4 a in the first spindle body 1 a. Polymerization is arranged sequentially from the outside in the radial direction toward the inside. The second unit includes a second spindle main body 1b that is detachably attached to the first spindle main body 1a with a bolt. Inside the second unit, a chuck portion 3 is provided at the tip, and the first spindle 4a is driven at the other end. A second spindle 4 b that is linked in a possible manner is rotatably supported via a bearing 16.

  The electric motor 14 is configured as a unique power source independent of the motor of the machine tool, and includes a stator 14a and a rotor 14b fixed to the inner periphery of the first spindle body 1b. As a type of the electric motor 14, there are a normal type in which a winding is wound around an iron core as a core, and a coreless motor in which the winding is solidified by a resin and the core is omitted. In the present invention, any type may be used, but it is more preferable to use a coreless motor because it is possible to suppress the radial dimension expansion of the spindle device. In other words, the core of the stator is literally omitted from the coreless motor, and the occupied space in the radial direction as the electric motor is compressed accordingly.

  The input shaft 2 driven by the electric power supplied from the electric motor 14 is rotatably supported on the inner periphery of the first spindle body 1a via bearings 6 at both ends in the axial direction. A hub 2b having a fourth gear A4 formed on the end face is fixed to one end of the inner periphery of the input shaft 2 with a bolt. Further, the speed increasing / decreasing mechanism 5 located radially inward of the input shaft 2 has basically the same structure as the first and second embodiments, but the hub in which the first gear A1 is formed. 8 is configured to be able to be intermittently connected to the first spindle main body 1 a via the switching mechanism 15.

  The switching mechanism 15 includes a movable sleeve 15a that is slidable in the axial direction on the outer periphery of the hub 8 via a ball spline mechanism, a first clutch 15b that connects the movable sleeve 15a to the spindle body 1, and a movable The second clutch 15c that connects the sleeve 15a to the input shaft 2, and the movable sleeve 15a is connected to the first clutch 15b, that is, the first position (the upper side in FIG. 4) and the second clutch 15c is connected to the first clutch 15c. It comprises an operation means 15d for selectively operating two positions (the lower state in FIG. 4).

  Therefore, when the movable sleeve 15a is in the first position, the hub 8 is fixed to the spindle body 1, the first gear A1 functions as a fixed gear, and a predetermined speed increasing / decreasing action with respect to the rotation of the input shaft 2 (this embodiment). In this case, the spindle 4 is driven to exhibit a predetermined machining capability as a high-speed spindle device. When the movable sleeve 15a is in the second position, the input shaft 2 and the hub 8 rotate together, and the speed increasing / decreasing action of the speed increasing / decreasing mechanism 5 is locked. Is transmitted to the spindle 4 as it is.

  The first spindle 4a includes a dog clutch 17 that cooperates with the second spindle 4b at one end, and a rotation sensor 18 at the other end. The first spindle 4a is rotatably supported on both sides of the inclined portion 10 via bearings.

  Therefore, the spindle device of the third embodiment has the following characteristics.

  First, since the electric motor 14 as a unique power source is integrally incorporated in the spindle body, the spindle device functions in a self-contained manner without being influenced by the power source of the machine tool. Will improve. Further, since the constituent members of the spindle device are arranged in the dead volume in the inner peripheral portion of the rotor of the electric motor, the entire device can be made compact. Moreover, since the components of the spindle device including the electric motor are arranged in the radial direction so that the driving force is transmitted from the radially outer side to the radially inner side, the torque transmission efficiency of the electric motor is increased. Will improve. Furthermore, since the speed increasing / decreasing action of the speed increasing / decreasing device can be limited according to the machining characteristics, the ability of the spindle device can be further diversified.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

In each of the above embodiments, the acceleration / deceleration operation by the acceleration / deceleration mechanism has been described for the example of two-stage acceleration / deceleration. It can also be limited to a one-step deceleration action between the first and second gears, and can be arbitrarily set as required.
In the spindle devices of the first to third embodiments, the speed increasing / decreasing mechanism is configured as a speed increasing mechanism. In any of the embodiments, an inclined portion is formed on the input shaft, and the rotating body is formed by the inclined portion. Can be configured so as to be rotatable, and the spindle can be linked to the fourth gear to constitute a speed reduction mechanism.

  That is, by changing the cooperation direction of the speed increasing / decreasing mechanism with respect to the spindle as the input shaft and the output shaft, it functions as a speed increasing mechanism or a speed reducing mechanism. Therefore, when configured as a speed increasing mechanism, the processing capability can be improved as a high speed spindle device, and when configured as a speed reducing mechanism, the processing capability can be increased as a high torque spindle device.

1 is a sectional view of a spindle device according to a first embodiment of the present invention. Explanatory drawing which shows the meshing part of the gear of the said Example. Sectional drawing of the spindle apparatus concerning 2nd Example of this invention. Sectional drawing of the spindle apparatus concerning 3rd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spindle main body 1a 1st spindle main body 1b 2nd spindle main body 2 Input shaft 3 Chuck part 4 Spindle 4a 1st spindle 4b 2nd spindle 5 Acceleration / deceleration mechanism 10 Inclination part 11 Ball 12 Rotating body 14 Electric motor 15 Switching mechanism
A1 1st gear
A2 Second gear
A3 3rd gear
A4 4th gear

Claims (7)

In the spindle apparatus configured to increase / decrease the rotation of the spindle with respect to the rotation of the input shaft, including an acceleration / deceleration mechanism between the spindle provided with a chuck portion for gripping the tool at one end and the input shaft,
The speed increasing / decreasing mechanism includes a rotating body that is rotatably supported at an inclined portion formed on the outer periphery or inner periphery of either the input shaft or the spindle, and the spindle body is attached to an end portion in the axial direction of the rotating body. Forming a second gear with n2 teeth meshing with the fixed first gear with n1 teeth and a third gear with n3 teeth meshing with the fourth gear with n4 teeth linked to the input shaft or spindle; A spindle device characterized in that it is configured as a swing type acceleration / deceleration mechanism that changes the meshing position between the gears while the rotating body swings on the inclined portion. The rotating body is rotatably supported at an inclined portion formed on the spindle,
The spindle device according to claim 1, wherein the input shaft is linked to the fourth gear. The rotating body is rotatably supported at an inclined portion formed on the input shaft,
The spindle device according to claim 1, wherein the spindle is linked to the fourth gear.   4. The spindle apparatus according to claim 1, wherein the speed increasing / decreasing mechanism is disposed in the axial direction between the input shaft and the spindle.   The speed increasing / decreasing mechanism and the spindle are respectively arranged in separate spindle bodies and configured as independent unit bodies, and the independent units are configured to be capable of transmitting rotational force. The spindle device according to any one of 1 to 4.   4. The input shaft according to claim 1, wherein the input shaft is configured as a cylindrical member, an acceleration / deceleration mechanism is disposed on an inner peripheral portion of the input shaft, and an electric motor is disposed on the outer peripheral portion. The spindle device according to one. The spindle device according to claim 1, wherein the speed increasing / decreasing mechanism includes a switching mechanism for limiting an speed increasing / decreasing action.

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