JP6717678B2 - Spindle device - Google Patents

Description

The present invention relates to a spindle device used when performing cutting work.

There are processing machines, such as lathes, boring machines, and gear processing machines, which hold a workpiece by a spindle (meaning "spindle") and perform cutting while rotating the spindle. For example, the gear processing device shown in the following patent document is one of them. The cutting process involves the generation of cutting chips (so-called “chips”, “chips”), and for example, the processing of the cutting chips becomes a problem. For example, if cutting waste adheres to and remains on the machined surface, it may lead to problems such as hindering the machining and damaging the machined surface.

JP, 2005-127077, A

In order to solve the above-mentioned problem, for example, providing a through hole in the spindle and discharging the generated cutting chips from the through hole is also under study. It seems that the spindle is also provided with a through hole in the gear machining device described in the above patent document, but the true meaning is not clear. Even if the chip is configured to be discharged from the through hole, it cannot be a sufficient technique unless the chip is properly discharged. The present invention has been made in view of such circumstances, and an object thereof is to provide a practical spindle device.

The spindle device of the present invention is
A spindle device used when cutting a workpiece,
A spindle for holding the work at one end, a holder for holding the spindle rotatably around its axis, and a rotary drive mechanism having a drive source for rotating the spindle around the axis,
The spindle is a hollow structure having a through hole extending along the axis, and is arranged so that the other end extends beyond the holder.
To generate the attached to the other end portion to rotate together with the spindle, the direction of flow toward the other end from the one end to the fluid in the through hole of the spindle, the outer periphery of the fluid by centrifugal force Equipped with an impeller to release ,
It is characterized in that it is used in a state in which cutting wastes at the time of cutting the work are received in the through hole of the spindle from the one end .

According to the spindle device of the present invention, when the cutting waste is discharged through the through hole of the spindle, the flow of the fluid generated by the impeller, that is, for example, the flow of the coolant, the flow of the air, etc., makes the cutting waste efficient. Will be discharged. By having such a function, the spindle device of the present invention becomes a practical spindle device.

1 is a perspective view showing a skiving machine provided with a spindle device that is an embodiment of the present invention. It is sectional drawing which shows the spindle device of an Example. It is a bottom view and a sectional view showing an impeller with which a spindle device of an example was provided.

In view of the above-mentioned functions, the spindle device of the present invention is preferably used in a state where cutting waste is received in the through hole from one end of the spindle. The spindle may directly hold the work, and when the chuck, jig, etc. are attached to one end, the spindle indirectly holds the work via the chuck, jig, etc. May be.

The fluid that causes a flow due to the impeller may be a liquid such as coolant or cutting oil applied to the workpiece when wet machining is performed, and a through hole when dry machining is performed. It may also be a gas, such as air, present in or accepted by the. For example, particularly when a large amount of coolant is applied to the work, it is desired that the coolant be efficiently discharged through the through holes. In detail, for example, if the coolant does not flow vigorously, it is expected that part of the coolant will not fit into the through hole and will overflow, causing cutting chips to adhere to the work due to the overflowed coolant. It In view of such a situation, the spindle device of the present invention is suitable for the spindle device used in a state in which the coolant applied to the work during machining is received in the through hole from one end of the spindle.

Discharging the cutting chips through the through hole of the spindle means that the inner peripheral surface of the hole provided in the workpiece, more specifically, the inner periphery of the hole when the axis of the hole is aligned with the axis of the spindle. It is suitable when cutting a surface. In view of this, the spindle device of the present invention exhibits sufficient merits when used when processing such an inner peripheral surface of such a work.

In addition, when the cutting waste is discharged through the through hole, and when the fluid is a liquid such as a coolant, it is possible to use gravity as well. It is preferable that one end portion that extends in the vertical direction or the direction that is inclined with respect to the vertical direction and that the one end portion that holds the work is positioned above and the other end portion that is provided with the impeller be positioned below. It is desirable to be used for a so-called vertical processing machine. In that case, from a different point of view, the impeller exerts the action of promoting or promoting the flow of the liquid due to gravity.

The spindle device of the present invention is not limited to the type of processing machine used. It can be used for various processing machines such as lathes, boring machines, gear cutting machines, and the like, and is particularly suitable for use in skiving processing machines. In cutting by a skiving machine, that is, in the processing for forming teeth, the cutting dust is a relatively small piece, so that, for example, as described above, the coolant has a through hole. If not properly discharged from the machine, such cutting chips are expected to adhere to the work due to the overflowed coolant. In consideration of the possibility that such an event may occur, the spindle device of the present invention is provided in a skiving machine, particularly a skiving machine that forms internal teeth on the inner peripheral surface, such as ring gear machining. When it is done, it is extremely effective.

In a processing machine that forms gear teeth, such as a skiving processing machine, the main shaft is tilted with respect to the cutter. In consideration of performing such processing on various works, it is desirable that the spindle device of the present invention includes an axis inclination changing mechanism for changing the inclination of the axis of the spindle.

The structure and shape of the impeller are not particularly limited. For example, an impeller is i) a substrate, ii) a facing plate that is opposed to the substrate at a distance from the substrate, and has a hole at the center that is connected to the through hole of the spindle, and iii) a substrate and a facing plate. In between, it is possible to employ an impeller configured to include a plurality of radially extending vane plates that are passed over the substrate and the counter plate. Such an impeller can be formed by a simple sheet metal working, unlike an impeller whose wings are three-dimensionally bent, which leads to a reduction in the manufacturing cost of the impeller.

Hereinafter, a spindle device according to an embodiment of the present invention will be described with reference to the drawings, after briefly describing a skiving machine provided with the spindle device. The spindle device of the present invention can be implemented in various modes other than the following examples, with various modifications and improvements based on the knowledge of those skilled in the art.

[A] Overall Configuration of Skiving Machine As shown in FIG. 1, a skiving machine provided with a spindle device of the embodiment has (a) a main body 10 and (b) a front surface of the main body 10. And a spindle head 12 of the embodiment described above, and (c) a machining head having a cutter rotating mechanism that rotatably holds a cutter 14 for forming internal teeth on a generally cylindrical work W and that rotates the cutter 14. 16 and (d) a head moving mechanism 18, which is supported by the main body 10 and moves the processing head 16 up, down, left and right.

The skiving machine is capable of forming teeth on the work W, and therefore, the spindle device 12 has an arbitrary axis around its own axis, that is, an axis extending in the front-rear direction about the axis of the spindle described later. An axis tilt changing mechanism 20 for tilting at an angle and changing the angle is provided. The work W is held at the upper end of the spindle device 12, more specifically, at the upper end of the spindle, as described in detail later. Although illustration is omitted, a nozzle for applying a coolant from above to the workpiece W held by the spindle device 12 during processing is provided.

[B] Configuration of Spindle Device As shown in FIG. 2, the spindle device 12 roughly rotates a spindle 30, a holder 32 that holds the spindle 30 rotatably around its axis L, and a spindle 30. For this purpose, a spindle motor 34 provided between the spindle 30 and the holder 32 and a chuck 36 attached to the upper end of the spindle 30 for holding the work W are configured. The spindle 30, the holder 32, the spindle motor 34, and the chuck 36 are configured by fastening a plurality of members, but the fastening structure between these members is omitted in the drawing.

The spindle 30 has a hollow structure in which a through hole 40 extending along the axis L is provided, that is, a cylindrical shape, and a flange is provided at the upper end portion. The holder 32 functions as a housing that rotatably supports the spindle 30, and through the roller bearing 44 and the ball bearing 46, the spindle 30 extends in the direction in which the axis L extends (hereinafter, may be referred to as “axial direction”). ) Is immovably and rotatably supported. Incidentally, the above-mentioned axis line inclination changing mechanism 20 is configured to rotate the axis line L of the spindle 30 by an arbitrary angle by rotating the holder 32. Therefore, the spindle 30 that holds the workpiece W via the chuck 36 at the upper end, which is one end, extends in the vertical direction or in the direction inclined with respect to the vertical direction, and the one end moves upward. That is, the lower end, which is the end, is positioned downward.

The spindle motor 34 functions as a drive source of a rotary drive mechanism that rotates the spindle 30 around the axis L, and includes a coil 50 held by a holder 32 and a magnet 52 attached to the outer periphery of the spindle 30. It is composed of. The spindle motor 34 is configured to control the rotation speed and rotation position of the spindle motor 34, that is, the rotation speed and rotation position of the spindle 30, based on a signal from an encoder (not shown).

The chuck 36 roughly includes a housing 56, a piston 58, and a grip cylinder 60. The housing 56 has a substantially bottomed cylindrical shape in which upper and lower members are fastened together. The piston 58 is arranged inside the housing 56. More specifically, the piston 58 has a cylindrical shape with a flange, and is arranged so that the flange is housed in an annular groove formed in the housing 56. Liquid chambers 62 and 64 for accommodating the hydraulic fluid are formed above and below the flange of the piston 58. Is designed to move up and down. The piston 58 is provided with a plurality of engaging rods 66 penetrating the housing 56 and extending upward from the flange. The grip cylinder 60 is internally mounted on the upper end side of the housing 56, and the engaging rod 66 is engaged with the grip cylinder 60. When the piston 58 moves downward, the grip cylinder 60 contracts and grips the work W by the action of the inclined surface formed on the housing 56. Conversely, when the piston 58 moves upward, the grip cylinder 60 expands in diameter by its own elastic force and the grip of the work W is released. Through the chuck 36 having such a structure, the spindle 30 holds the work W at the upper end which is one end of itself. The liquid passages for introducing/discharging the hydraulic fluid to/from the liquid chambers 62 and 64 are omitted in the figure.

A hole is formed in the center of the bottom of the housing 56 of the chuck 36, and the through hole 40 of the spindle 30 and the inside of the chuck 36 are connected to each other by the hole in the center spindle device 12. In other words, a fluid passage extending vertically is formed so as to penetrate the chuck 36 and the spindle 30.

Here, the work W held by the main spindle device 12, that is, the work W to be subjected to skiving processing, has a generally cylindrical shape, as shown by a two-dot chain line in the figure, and has teeth on its inner peripheral surface. Processing for forming is performed. That is, the work W has a hole, is held with the axis of the hole aligned with the axis L, and the inner peripheral surface of the hole is cut.

In the main spindle device 12, the impeller 70 is attached to the lower end which is the other end of the spindle 30. As shown in FIG. 3, the impeller 70 includes a (A) substrate 72, and (B) a substrate 72 facing the substrate 72 with a space therebetween, and a hole 74 connected to the through hole 40 of the spindle 30 in the center. And a (C) a plurality of blade plates 78a, 78b, 78c extending radially between the substrate 72 and the counter plate 76 between the substrate 72 and the counter plate 76. Has been done. Incidentally, FIG. 3A is a IIIa-IIIa cross section in FIG. 3B.

Although the vane plates 78a, 78b, 78c have different lengths, their outer peripheral ends coincide with the outer peripheral ends of the substrate 72 and the counter plate 76. Therefore, the positions of the inner peripheral ends of the vane plates 78a, 78b, 78c are different from each other. More specifically, the four longest blades 78a are arranged at an equal angular pitch, and the four blades 78b having an intermediate length are arranged in the middle of the blades 78a and the shortest blade 78c. Are arranged exactly in the middle between the blade plate 78a and the blade plate 78b.

Each of the vane plates 78a, 78b, 78c is formed as an annular portion 80 on the inner peripheral end side. The blade plates 78a, 78b, 78c are joined to both the substrate 72 and the counter plate 76 to fix the substrate 72 and the counter plate 76 to each other. The annular portion 80 of the short blade 78c is used to fasten the bolts 82 and nuts 84. Further, the impeller 70 is attached to the lower end of the spindle 30 by a bolt 86 using the annular portion 80 of the long blade plate 78a.

With the impeller 70 having the structure as described above, in the main spindle device 12, the through hole 40 of the spindle 30 and the outer periphery of the impeller 70 are connected via the space between the blade plates 78a, 78b, 78c, A fluid flow path is formed. The impeller 70 rotates integrally with the spindle 30 as the spindle 30 rotates.

[C] Action by Impeller With this skiving machine, when gear cutting is performed on the inner peripheral surface of the work W, a large amount of coolant is discharged toward the work W, and as shown in FIG. Most of the generated coolant is discharged downward through the through hole 40 of the spindle 30. The chips produced by the machining are small pieces, and the chips should be discharged downward together with the coolant through the through hole 40. However, when the amount of the coolant becomes considerably large, it is expected that the flow of the coolant through the through hole 40 is not sufficient. In extreme terms, the coolant may overflow above the work W. In such a case, the cutting chips may drift inside the work W or adhere to the inner peripheral surface of the work W, that is, the machined surface, especially when it is in the form of small pieces. In that case, the cutting scraps may cause scratches on the surfaces of the cut teeth.

The impeller 70 is effective in avoiding the above situation. Specifically, as shown by the thick arrow in FIG. 2, when the spindle 30 rotates and the impeller 70 rotates, the coolant inside the impeller 70 is vigorously discharged from the outer periphery of the impeller 70 by the centrifugal force, whereby The coolant inside the through hole 40 is sucked downward. As a result, the flow of the coolant inside the through hole 40, specifically, the flow velocity is promoted. As a result, the coolant vigorously flows downward, and the flow of the coolant also discharges the cutting chips properly, in other words, efficiently.

As described above, the impeller 70 attached to the other end (lower end) of the spindle 30 moves from one end (upper end) to the other end toward the fluid in the through hole 40, specifically, the coolant. It is an effective means to generate directional flow. In other words, it is an effective means for promoting the flow. Therefore, by adopting the main spindle device 12, that is, the main spindle device 12 in which the impeller 70 exhibiting the above-described action is attached to the spindle 30, the workpiece machined by the skiving machine is not damaged by the machining. Is suppressed.

12: Spindle device 20: Axis inclination changing mechanism 30: Spindle 32: Holder 34: Spindle motor [rotary drive mechanism] [driving source] 36: Chuck 40: Through hole 70: Impeller 72: Substrate 74: Hole 76: Opposing plate 78a , 78b, 78c: vane W: work L: spindle axis

Claims (7)

A spindle device used when cutting a workpiece,
A spindle for holding the work at one end, a holder for holding the spindle rotatably around its axis, and a rotary drive mechanism having a drive source for rotating the spindle around the axis,
The spindle is a hollow structure having a through hole extending along the axis, and is arranged so that the other end extends beyond the holder.
To generate the attached to the other end portion to rotate together with the spindle, the direction of flow toward the other end from the one end to the fluid in the through hole of the spindle, the outer periphery of the fluid by centrifugal force Equipped with an impeller to release ,
A spindle device, which is used in a state in which cutting waste generated during cutting of the work is received in the through hole of the spindle from the one end . The impeller is
Board,
An opposing plate that faces the substrate with a distance from the substrate, and has a hole connected to the through hole of the spindle in the center,
The spindle device according to claim 1, further comprising: a plurality of blade plates extending between the substrate and the counter plate and extending radially between the substrate and the counter plate. The spindle device according to claim 1 or 2, wherein the spindle device according to claim 1 or 2 is used in a state in which a coolant to be applied to the work during cutting is received in a through hole of the spindle from one end. The workpiece has a hole, in any one of claims 1 to 3 used in cutting an inner peripheral surface of the hole the axis of the hole while being coincident with the axis of the spindle The described spindle device. It said spindle extends inclined direction with respect to the axis of it or vertical direction in the vertical direction, and said one end upward, used the other end so as to become an attitude that is located below The spindle device according to any one of claims 1 to 4 . The spindle device according to any one of claims 1 to 5, further comprising an axis tilt changing mechanism that changes a tilt of the axis of the spindle. Spindle device according to any one of claims 1 to 6 Ru deployed in skiving machine.

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