JP2002144149A - Gear cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the entry of heated chips into a moving device by avoiding the accumulation of chips such as cutting chips and cutting fluid on the top plate of a gear cutter in the gear cutter for machining a spiral bevel gear. SOLUTION: A work spindle 18 is fixedly installed on a device body upward in vertical direction, and a chip dropping hole 32 is formed between a work unit 12 and a tool unit 14. A gutter 36 is disposed under the chip dropping hole 32, and a chip collecting box 40 and a cutting fluid tank 42 are installed adjacent to the lower end of the gutter 36. Thus, chips and cutting fluid can be collected separately from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral bevel gear,
The present invention relates to an improvement in a gear cutting device for processing a bevel gear such as a hypoid gear.

[0002]

2. Description of the Related Art As a method of cutting a spiral bevel gear such as a spiral bevel gear, a hypoid gear and the like, a forming gear cutting method is generally performed. The forming gear cutting method assumes a virtual beveled bevel gear that meshes with a beveled bevel-shaped small gear (pinion), and sets the rotation axis (referred to as a tool spindle) of a tool such as a front milling cutter or a front hob to the virtual beveled bevel. By tilting the tool spindle around the cradle axis while maintaining its relative positional relationship with respect to the rotation axis (called the cradle axis) of the toothed gear, the tool rotates the tooth surface of the virtual bevel gear. Exercise to exercise. Then, by rotating the workpiece so as to mesh with the virtual spiral bevel gear, a small spiral bevel gear (pinion) meshing with the virtual spiral bevel gear is created. However, the tilt mechanism for tilting the tool spindle has a complicated structure, which increases the equipment cost, and is not suitable for high-speed operation, and it is difficult to improve the production efficiency.

On the other hand, Japanese Patent Publication No. 07-085843
In the publication, instead of providing a tilt axis for tilting the tool, the relative movement of the tool spindle and the workpiece spindle, the rotation around the respective central axes, and the workpiece spindle is orthogonal to the central axis of the workpiece spindle. There is described a gear cutting device that realizes a rotating motion while meshing a virtual bevel gear and a spiral bevel gear by combining rotation around a rotation axis. This gear cutting device includes a tool spindle, a workpiece spindle, a rotation axis for relatively rotating the tool spindle and the workpiece spindle about a rotation axis orthogonal to the tool spindle, the tool spindle and the workpiece spindle. Each has a relative movement device rotatably supported about a horizontal central axis and relatively moving along each of three straight lines perpendicular to each other. Specifically, a work headstock is provided on the base,
It is movable along a straight line extending in the horizontal direction, and is rotatable around a rotation axis extending in the vertical direction, and the workpiece spindle is placed on the workpiece headstock around a horizontal central axis. While being rotatably held, a tool headstock that rotatably holds the tool spindle is provided, and the tool headstock is arranged in a direction parallel to the straight line and two directions orthogonal to the direction and orthogonal to each other. It is attached to the base via a moving device for moving.

[0004]

In the gear cutting device, the generation of chips is inevitable, and a cutting fluid such as a cutting oil or a suspension is used in many cases. On the other hand, in the above-described gear cutting device, it is necessary to move the work headstock that holds the work during the generating motion, and to turn the work headstock accurately around the rotation axis at a minute angular velocity. An object headstock moving device and a rotating device are disposed in a so-called dirty zone where chips, cutting fluid and the like fall or scatter. For this reason, it is essential to frequently clean the work headstock within the range of motion, and even if cleaning is performed frequently, cutting fluid or chips may enter the work headstock moving device or the guide device of the rotating device. As a result, it is difficult to prevent the guide surface from being contaminated or damaged, and the accuracy of movement and rotation of the work headstock from being reduced.
Further, since the chips are at a high temperature, if they are deposited on the apparatus main body, the chip heats up the apparatus main body and causes a reduction in processing accuracy.

The gear cutting device for processing a bevel-shaped bevel gear (pinion) by the shaping gear cutting method has been described above. Even in a gear cutting device that processes a bevel-shaped bevel gear and a bevel-geared small gear, the work headstock is often moved along a straight line, and the rotation is orthogonal to the straight line. It may be pivotable about an axis. The above problem also occurs in a gear cutting device for performing the generating gear cutting method in substantially the same manner.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to reduce or eliminate at least one of the above-described problems in a gear cutting device that performs at least one of a molding gear cutting method and a creative gear cutting method. Was done as an issue,
According to the present invention, the following gear cutting devices are obtained. As in the case of the claims, each aspect is divided into sections, each section is numbered, and if necessary, the other sections are cited in a form in which the numbers are cited. This is for the purpose of facilitating the understanding of the present invention and should not be construed as limiting the technical features and combinations thereof described in the present specification to those described in the following sections. . Further, when a plurality of items are described in one section, the plurality of items need not always be adopted together. It is also possible to select and adopt only some of the items.

(1) An apparatus main body, a workpiece headstock which is provided so as to be immovable relative to the apparatus main body, and which holds the workpiece main shaft so as to be rotatable around a central axis and axially immovable, and A workpiece spindle motor, which is a numerically controllable electric motor that rotationally drives the workpiece spindle, and an X-axis and a Y-axis that rotate the tool spindle around a central axis and are orthogonal to each other.
A tool spindle holding device that holds a linear motion in three directions parallel to the axis and the Z axis, and a pivotable axis about one of the X, Y, and Z axes and a central axis of the tool spindle. An X-axis moving device, a Y-axis moving device, and a Z-axis moving device for moving the tool spindle in each of the three directions of the X-axis, the Y-axis, and the Z-axis; Spindle motor for rotating the tool, and controlling the electric motors of the X-axis moving device, the Y-axis moving device, and the Z-axis moving device, and the workpiece spindle motor and the tool spindle motor, thereby attaching the tool spindle to the tool spindle. A control device for performing a motion such as a tooth of a virtual spiral gear that rotates while meshing with the spiral bevel gear attached to the workpiece spindle, A part of the device body, which is located below a machining space where the front gear cutting tool performs the machining of the workpiece, has a shape in which chips generated by the cutting process are prevented from remaining on the device body. Apparatus (Claim 1). The virtual bend gear is a crown gear at the time of processing by the generating gear cutting method, and is a bevel gear at the time of processing by the forming gear cutting. In both cases, when machining a bevel-shaped bevel-shaped small gear, the tool spindle is rotated by a rotating device in synchronization with the rotation of the tool and the workpiece during gear cutting. On the other hand, when the bevel gear is machined by the shaping method, the rotation position of the tool spindle around the rotation axis is deflected before the start of the gear cutting, but during the gear cutting. Cannot rotate. In the apparatus described in this section, the work headstock is provided so as to be relatively immovable in the apparatus main body, so that there is no need to provide a moving device or a rotating device in a so-called dirty zone on the apparatus main body. Therefore, it is possible to satisfactorily avoid cutting fluid or chips entering the guide device of the moving device or the rotating device, thereby contaminating or damaging the guide surface and the like, and lowering the processing accuracy and durability of the gear cutting device. . In addition, it is desirable to provide a cover or the like on the work headstock in order to prevent damage or the like due to chips, but in this case, it is not necessary to form a notch or the like to avoid interference with the movable part. Furthermore, only the workpiece spindle motor for rotating and driving the workpiece spindle is required to be provided on the workpiece spindle head, and the configuration of the workpiece spindle head is simple. Regarding the tool spindle holding device, it is possible to adopt a configuration in which a moving device or the like is not provided immediately below a portion where the tool contacts with the workpiece and in a peripheral area thereof. Mixing of cutting fluid, chips and the like can be avoided. In addition, since chips are prevented from remaining on the apparatus main body, it is easier to prevent chips from entering a moving device, a rotating device, or the like, or the apparatus body is heated by high-temperature chips or the like. Therefore, it is possible to favorably prevent the processing accuracy from lowering due to thermal expansion. An example of a specific measure to achieve a “shape to avoid chips remaining on the device body” is the formation of chip drop holes in item (6). A slope may be formed. (2) An electric motor that can be numerically controlled, a turning device for turning the tool spindle around the turning axis is included, and the control device is the X-axis moving device, the Y-axis moving device, and the Z-axis moving device. By controlling each electric motor of the axis moving device, the electric motor of the rotating device, the workpiece spindle motor, and the tool spindle motor, the blade portion of the front gear cutting tool attached to the tool spindle is attached to the blade. The virtual bevel gear that rotates while meshing with the bevel gear attached to the main shaft is used to move the teeth (1).
The gear cutting device according to claim (claim 2). A rotating device equipped with a numerically controllable electric motor causes the tool spindle to rotate the tool spindle and the workpiece around its central axis and a rotating axis orthogonal to any of the X, Y and Z axes during gear cutting. By synchronously rotating the gears, it is possible to realize the creation of a gear by a molding gear cutting method without providing a tilt mechanism. This will be described in detail in the section of the embodiment of the invention. (3) The tool spindle holding device holds the workpiece spindle so as to be rotatable around a central axis and immovable in the axial direction, and the tool spindle is attached to the X axis, Y axis, and Z axis. Linear motion in three parallel directions and their X axis, Y
The gear cutting device according to the above mode (1) or (2), including a tool headstock holding device that rotatably holds the rotary shaft about a rotation axis perpendicular to a central axis of the tool spindle. . When the tool spindle is moved in the axial direction, it is also possible to relatively move the tool spindle in the axial direction with respect to the tool spindle that holds the tool spindle rotatably around the central axis, and the above-mentioned (1) And the gear cutting device described in (2) also includes the mode. However, as described in this section, it is more convenient to hold the workpiece spindle on the tool spindle so as to be rotatable about the center axis and immovable in the axial direction, and to move the tool spindle in the axial direction of the tool spindle. Often. For example, a guide device for guiding in a direction parallel to the axial direction of the tool spindle can be provided at a position far from the machining space, so that chips and the like can be effectively prevented from entering the guide device. Can be. In addition, a highly reliable moving device for moving the tool spindle in the axial direction can be easily obtained. (4) The gear cutting device according to any one of (1) to (3), wherein the workpiece headstock holds the workpiece spindle rotatably about a substantially vertical center axis. 3). It is also possible for the workpiece headstock to hold the workpiece spindle rotatably about a substantially horizontal or inclined central axis. However, if it is held rotatably about a substantially vertical center axis, the horizontal cross-sectional area of the work headstock can be reduced, or an electric motor or the like for rotating the work spindle can be used in the apparatus main body. The apparatus main body can be miniaturized. Further, it becomes easy to form the apparatus main body into a shape that avoids the swarf generated by cutting. Furthermore, it is often easier to attach the workpiece to the workpiece spindle. This effect is particularly significant when the work piece is mounted by an operator. (5) The upper surface of at least a portion of the workpiece headstock located below the machining space is an inclined surface that is inclined in a direction of being located lower as the portion is farther from the workpiece spindle, and the apparatus is further provided. The gear cutting device according to the above mode (4), wherein the main body is shaped so as to allow the chips that have slipped down the slope of the work headstock to move further downward. According to the device described in this section, chips and the like generated during processing can be favorably moved downward. (6) The workpiece headstock holds the workpiece spindle in a posture substantially parallel to the plane of rotation of the tool spindle and substantially horizontal, and the apparatus main body is configured to be in the processing space. The tooth cutting device according to any one of (1) to (5), wherein a space is formed in a portion located below the space so as to allow the chip to drop to a space below the device main body. apparatus. In the gear cutting device described in this section, the rotation axis of the tool spindle can be set at an arbitrary angle in a vertical plane orthogonal to the workpiece spindle, and the degree of freedom in layout is improved. However, as described in the next section, it is desirable that the rotation axis of the tool spindle is substantially horizontal. (7) The tool spindle holding device holds the tool spindle so as to be rotatable about a substantially horizontal rotation axis perpendicular to the workpiece spindle. A gear cutting device according to any one of the claims. In the device described in this section, a mode in which the tool spindle is rotated in a posture close to horizontal and a mode in which the tool spindle is rotated in a posture close to downward are considered. Among these, if the rotation is performed in a posture close to the downward direction, the rotation axis is arranged at a position higher than the processing portion, and it becomes easier to avoid the swarf or the like from scattering around the rotation axis. (8) A chip drop hole that allows chips to fall below the top plate is formed in the top plate of the apparatus body and located below the processing space. (1) to (7) A gear cutting device according to any one of claims (Claim 4). According to the gear cutting device described in this section, chips can be prevented from remaining on the device main body by a simple configuration in which a chip drop hole is formed in the support surface. It is desirable that nothing is provided above the chip drop hole of the apparatus main body. (9) The gear cutting device according to (8), wherein the top plate of the apparatus main body and the periphery of the chip drop hole is inclined so as to be lower as a portion closer to the chip drop hole. ). If it is a top plate and the periphery of the chip drop hole is formed so as to be inclined toward the chip drop hole, the cutting fluid or chips scattered around the chip drop hole will be guided to the chip drop hole with a simple configuration. I will (10) A chip collecting device for collecting chips dropped through the chip drop hole is provided inside the apparatus main body.
The gear cutting device according to claim (8) or (9) (claim 6). A storage box capable of storing a certain amount of chips may be provided, and chips may be collected by an operator or the like, or a chip discharging device such as a belt conveyor may be provided, and chips may be removed from the device body at any time. May be carried out from the vehicle.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gear cutting device according to an embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 10 denotes a bed on which a workpiece unit 12 and a tool unit 14 are provided.
The workpiece unit 12 includes a workpiece spindle 18, a workpiece headstock 20 that supports the workpiece spindle 18, a drive motor 22 that rotates the workpiece spindle 18, and the like. The work headstock 20 is provided on the bed 10 so as to be relatively immovable. That is, they are fixed. In particular,
As shown in FIG. 3, the work unit 12 is fixed on the top plate 24 of the bed 10, and a pair of support members 26 are provided on the top plate 24, and the tool unit 14 is supported by the support members 26. I have. A pair of support members 26
Extends in the longitudinal direction of the bed 10 (Y called ₂ axial direction), direction perpendicular thereto in the horizontal plane (Z ₂
(Referred to as the axial direction). The support members 26 each have a pair of support legs 28, and are fixed to the top plate 24 of the bed 10 at the support legs 28.

[0009] the workpiece headstock 20, workpiece spindle 18 is rotatably held about an axis extending in the vertical direction (X referred to as _two-axis direction), the workpiece (work) 30, its axis Is held in a posture extending in the vertical direction. Further, as shown in the figure, the workpiece spindle 18 has a shape in which a truncated cone and a cylindrical body are alternately arranged in the axial direction, and is provided with an upward horizontal surface facing upward. Absent. Further, the work headstock 20 is provided with a cover 29.
And the cover 29 is inclined so as to be lower as the cover 29 approaches the tool unit 14.
Therefore, chips and the like generated when the workpiece 30 held by the workpiece spindle 18 is subjected to the gear cutting are removed by the workpiece spindle 1.
It is slid down onto the bed 10 along the slope of the cover 8 and the cover 29. Although the drive motor 22 is fixed on the top plate 24 in the present gear cutting device, it may be provided so as to be accommodated in the bed 10.

[0010] The top plate 24 of the bed 10
An allowable chip drop hole 32 is formed. However,
In FIG. 1, the chip drop hole 32 is positioned behind the workpiece headstock 20.
Hidden and invisible. The chip drop hole 32 is shown in FIGS.
As shown, the workpiece unit 12 and the tool unit 14
Is formed between. Furthermore, a chip drop hole of the top plate 24
32 becomes lower as the periphery of the chip 32 approaches the chip drop hole 32.
It is tilted. Because of this,
Chips dropped or scattered to pass through pilot hole 32
Not only the chips but also the chips scattered around it fall well
It is led to the hole 32. The inside of the bed 10 is almost hollow
And a plurality of partition plates 34 are arranged in the horizontal and vertical directions.
And the bed 10 is reinforced. Be
Inside the chip 10 and below the chip drop hole 32,
36 are provided. The toe 36 is in a nearly horizontal position
But Y_TwoWhen approaching the work headstock 20 in the axial direction,
And tilted downward (see FIG. 2).
Z_TwoThe lower the distance from the workpiece spindle 20 in the axial direction
(See FIG. 3). _Twoaxis
To the length protruding from the side wall 38 of the bed 10 in the direction
Is formed. Protruding from bed 10
A chip box 40 is disposed adjacent to the end on the other side. Off
The trash box 40 receives the chips and the like that have been led to the toy 36
It is arranged as follows. The bottom of the chip box 40 is a net-like material
Material, and solid chips are collected, but the cutting fluid is
To be discharged to Further below the chip box 40
Is provided with a cutting fluid tank 42, in which the cutting fluid is
Collected. In this processing equipment, solid chips and
The cutting fluid is separated and collected. In addition, 3
6, instead of the chip box 40 and the chip box 40,
Belt conveyor as a transfer device at the
Debris and cutting fluid are automatically carried out of the bed together
You may make it.

[0011] the tool unit 14, the guide rail 50 which is fixed on the support member 26 extending in the Y ₂ axially, and a movable Y ₂ axis slide 52 or the like along the guide rail 50. The Y ₂ axis slide 52 is moved by a drive motor 54. A guide rail 56 extending in the Z ₂ axis direction is provided on the Y ₂ axis slide 52.
6 is provided with a Z _two- axis slide 58. The Z _2- axis slide 58 is moved by a drive motor 60. Z
_A column 62 is provided upright on the biaxial slide 58. The side surface (the workpiece headstock 20 side of the vertical plane) 64 of the column 62, guide rails 66 extending in the vertical direction (X ₂ axial direction)
It is mounted on the guide rail 66, X ₂ axis slide 6
8 is attached. X ₂ axis slide 68 is driven by a drive motor 70. X ₂ the rotation base 74 in the vertical surface 72 of the workpiece spindle # 20 side in the axial slide 68 is mounted rotatably parallel to the pivot axis about the Y ₂ axis, the tool to the turntable 74 The spindle head 76 is fixed. As a result, the tool spindle head 76 is rotatable to any angle of inclination in a parallel vertical plane X ₂ -Z ₂ plane. The rotating table 74 is rotated by a rotating motor 78 in the Y direction.
_The tool spindle 80 is rotated about _two axes, and is rotated by a drive motor 82. The tool spindle 80 holds a front milling cutter 84 as a processing tool.

As described above, the tool spindle head 76 is relatively movable with respect to the bed 10 in the X ₂ , Y ₂ , and Z ₂ axis directions, and is rotatable in a vertical plane (the inclination angle can be changed). Is provided. On the other hand, the work headstock 20 is fixed to the bed 10. Each of the drive motors 22, 54, 60, 70, 78 is a servomotor whose rotation amount can be controlled. In this gear cutting device, the rotation of the workpiece 30 held on the workpiece spindle 18 and the tool By combining the rotation and rotation of the face mill 84 held by the main shaft 50 with the horizontal movement and the vertical movement, a tooth space is created in the workpiece 30.

The present gear cutting device is provided with a gear cutting control device. The input unit of the gear cutting control device is connected to the above-described drive motors 22, 54, 60, 70 and an encoder that detects the rotation angle of the rotation motor 78, and the output unit is connected to the above-described drive motors 22, 54, 60, 70, 78, etc. are connected via a drive circuit. X ₂ , Y ₂ , Z _{2 of the} tool spindle head 76 based on the output signals from the encoders
Position in the axial direction, and (inclination angle with respect to Z ₂ axes) rotation angle around Y ₂ axis, rotation angle of the workpiece 30 is obtained, the operating state of the drive motor is controlled based on these. The rotation of the front milling cutter 84 is controlled by the control of the drive motor 82.

The present gear cutting device can create a curved bevel gear that meshes with a virtual bevel gear. The pinion can be created by the shaping method. The present gear cutting device can, of course, create a bevel gear bevel gear that meshes with the virtual crown gear (creating a gear and a pinion by the new gear cutting method). Only the point that (control of the inclination angle) is not performed is different from the creation of the pinion by the shaping method, and the detailed operation is described in JP-A-11-262816 according to the present applicant. Therefore, the description is omitted.

First, creation of a pinion by a shaping method using a conventional gear cutting device will be briefly described. As is generally known, the molding gear cutting method is used as a virtual gear.
Assuming a bevel gear (gear) itself that meshes with the pinion to be machined, move the tool to sweep over the tooth surface of the virtual bevel gear, and rotate the workpiece to mesh with the virtual bevel gear. This creates one tooth (accurately, one streak) in the workpiece. This is repeated to create a pinion, so that a gear meshing with it can be made by forming gear cutting, and the beveled bevel gear pair can be made more efficiently than the cutting gear cutting method in which both are made by forming gear cutting. (Pinions and gears).

FIG. 4 conceptually shows a main part of a conventional gear cutting device. In the conventional gear cutting device, in order to realize the above-described generating motion, (a) a cradle axis as a rotation axis for generating the generating motion, and (b) a tool spindle in a cradle plane orthogonal to the cradle axis are required. An eccentric shaft (eccentric cylinder) for moving to a position, and (c) a swivel shaft as a mechanism for fixing the direction of the tool in a predetermined direction in the circumferential direction.
(d) A mechanism (tilt axis) for tilting the tool is required. In the figure, the movement elements for realizing the above-described creation movement are indicated by arrows. FIG. 4 is an enlarged view of the cradle rotating body for easy understanding.

[0017] Hereinafter, for simplicity of explanation, and Z ₁ axis the axis of the cradle axis, an axis orthogonal to each other on the cradle plane perpendicular to the cradle axis X ₁ axis, and Y ₁ axis, defined by their the coordinate system of the conventional coordinate system X ₁ -Y ₁
It referred to as -Z _1. In conventional gear cutting apparatus, Y ₁ the tool support base 100, not shown, which is orthogonal with the X ₁ axis direction is a direction parallel to the plane, and its X ₁ axis in the paper plane
It is provided on a moving device that can move in the axial direction. The tool support base 100, the cradle rotating body 10 which rotates around the cradle axis (Z ₁ axis) perpendicular to the X ₁ -Y ₁ plane
2, the eccentric sleeve 103 is rotated about parallel eccentric axis O _E in the cradle axis (Z ₁ axis), the eccentric sleeve 10
Provided at three, parallel swivel axis Z ₁ axis (not shown)
And a tilt mechanism 106 for tilting the tool spindle 105 with respect to the cradle axis while holding the tool spindle 105 rotatably at an eccentric position of the cradle rotating body 102. A face mill 107 as a machining tool is held on the tool spindle 105. Cradle axis (Z
₁ ) coincides with the rotation axis of the virtual gear which is a virtual spiral bevel gear, and the cradle rotating body 102 is rotatable about its axis. The center of rotation of the cradle rotating body 102 is referred to as a center of rotation O. In contrast, the workpiece headstock 108 is movable in Y ₁ axis direction perpendicular to the horizontal X ₁ axis in the apparatus main body. The workpiece headstock 108 holds the workpiece spindle 110 in a posture parallel to the horizontal plane X ₁ -Z ₁ and inclined at an angle within a certain range with respect to the cradle axis (Z ₁ axis). and, it provided on the base to be movable in the Z ₁ axial direction. A workpiece 11 as a workpiece on a workpiece spindle 110
1 is held. Workpiece headstock 108 further includes
_It is rotatable around an axis parallel to _one axis. However, before and after machining the work headstock 108,
It is rotated and moved for the purpose of exchanging the workpiece and adjusting the orientation of the workpiece. During the processing, only the rotational movement for rotating the workpiece about the workpiece spindle is performed.

The relative position and relative movement between the tool spindle 105 and the workpiece spindle 110 will be described in more detail with reference to FIGS. Here, in a plane parallel to the Z ₁ axis includes a tool spindle 105 as shown in FIG. 8, and the angle the axis of the tool spindle 105 and the cradle axis and the (Z ₁ axis) is a tilt angle i, 5 and As shown in FIG. 7, the intersection of a plane including a circle drawn by the cutting edge when the tool is rotated and the axis of the tool spindle 105 is defined as the center of the tool edge c, and from the center of the tool edge c along the axis of the tool spindle 105 to the rear of the tool. A unit vector heading toward is defined as a vector a. Incidentally, the tool edge center c, and the distance to the cradle axis (Z ₁ axis) and turning radius S. Workpiece spindle 110 is disposed offset with respect to the cradle axis (Z ₁ axis), and are tilted at an angle γ with respect to the cradle plane (X ₁ -Y ₁ plane). Specifically, the workpiece spindle 110
Is that the Y ₁ axis component is 0 and horizontal, and X ₁ -Z
They are moved away to Y ₁ axially by a distance E _P with respect to _one plane (see FIG. 7). Furthermore, the point the axis of the workpiece spindle 110 is spaced a distance Xb from the rotation center O to Z ₁ axial direction b
Intersect the Z ₁ axis in.

The center c of the tool edge is aligned with the cradle shaft (Z
₁It moves while drawing a circle of radius S around the axis)
The tool spindle 105 has a line segment of radius S and a cradle axis (Z₁
Vector a on the tool spindle 105 tilted with respect to the axis
And cradle shaft (Z₁Around the axis)
To rotate. The base end of the vector a, ie the center of the tool edge
Let the coordinates of c be (X_1s', Y_1s', Z_1s') And the vector a
The coordinates of the tip of (X_{1f '}, Y _{1f '}, Z_{1f '})
The vector a can be represented by [Equation 1], and the cradle shaft
(Z₁Axis) and the tilt angle i while maintaining the cradle axis
It can be said that it is a creative movement.

(Equation 1)

In order to create the workpiece 111,
Milling cutter 107 is cradle axis (Z ₁Axle)
The area to be moved is defined as the tool swivel area, and the tool swivel area
The tool tip position indicating the tool edge position in the
The rotation angle Δq is the tip position rotation angle. Where the rotation angle Δq is the X axis
Is a value that becomes 0 degrees in a state parallel to.

The coordinate system X shown above₁-Y₁-Z₁And each para
Based on the meter, the operation of the gear cutting device
Get movement. Here, the coordinate system X shown in FIGS._Two
-Y_Two-Z_TwoSets the workpiece spindle to X_TwoDefined as an axis
You. Based on this, the conventional coordinate system X₁-Y₁-Z₁From
Coordinate system X in this gear cutting device_Two-Y_Two-Z_TwoConvert to
The process will be schematically described. As described above, the workpiece spindle 18
Is the rotation center O (ie, the conventional coordinate system X₁-Y₁-Z₁
At the origin), Y₁Ep, Z in the axial direction₁Axial direction
Are offset from each other by Xb.₁
Y to axis₁Tilted around the axis by an angle γ
I have. Conventionally, these misalignments and tilts are eliminated.
Coordinate system X₁-Y₁-Z ₁Move and rotate X₁X axis_Two
Align with the axis. FIG.₁, Z₁The above movement and rotation of the shaft
State after doing₁’And Z₁’Axis
You. In that state, X_TwoAngle around axis
θ_wxAnd rotate the coordinate system after rotation to coordinate system X._Two-Y_Two
-Z_TwoAnd Therefore, the conventional coordinate system X₁-Y₁-Z₁
From coordinate system X_Two-Y_Two-Z_TwoThe coordinate transformation matrix T to be transformed into
It can be shown as [Equation 2]. Note that the angle θ_wxTo
This will be described in detail below.

(Equation 2)

The angle θ _wx is a value based on the rotation angle Δq of the tool edge position of the tool spindle (specifically, the value of the vector a when the rotation angle is Δq), and is obtained by the following calculation. In this gear cutting device, the tool spindle 80 is X ₂ −
Since it is possible to turn only in a vertical plane parallel to the Z ₂ plane, a direction orthogonal to the vertical plane (Y ₂ axis direction)
The component must always be zero. In order to realize this, a conventional cradle rotating body 102 provided with a tilt mechanism 106 rotates a work spindle 110 of the cutting device so as to mesh with a virtual bevel gear, and further, a Y ₂ axis of a tool spindle 105. Turn to adjust the directional component. As shown in FIGS. 9 and 10,
If the tool spindle 105 and the workpiece spindle 110 are rotated around the workpiece spindle 110 while maintaining the relative position between the tool spindle 105 and the workpiece spindle 110, the tool spindle 105
Can be determined angle of Y ₂ axial component becomes 0 uniquely. An additional rotation is applied to the work spindle 110. The rotation angle of the workpiece spindle 110 at this time is defined as an additional rotation angle θ _wx, and the Z
The inclination with respect to _two axes and the tilt angle i _T. The work spindle 110 and the tool spindle 105 converted by the above-described operations.
Is acquired as the relative position and rotation phase of the workpiece spindle 18 and the tool spindle 80 of the gear cutting device according to the present embodiment. 9 and 10
, The state A of the cutter before giving the additional rotation angle θ _wx is shown by a broken line, and the state B of the cutter after giving the additional rotation angle θ _wx is shown by a solid line.

Further, the additional rotation angle θ _wx and the tool inclination angle i _T will be specifically described. If the unit vector a on the tool spindle 105 is converted using the above-described coordinate conversion matrix T, the unit vector a ₂ on the tool spindle 80 of the present gear cutting device in the coordinate system X ₂ -Y ₂ -Z ₂ can be expressed as 3].

(Equation 3)

The unit vector a ₂ is determined so as to be parallel to the X ₂ -Z ₂ plane in the coordinate system X ₂ -Y ₂ -Z _{2 using the} work spindle 18 as the X ₂ axis. In other words, the additional rotation angle θ _wx is set so that the component (Y _{2f ′} −Y _{2s ′} ) in the Y ₂ axis direction of the unit vector a ₂ that has been subjected to coordinate conversion as shown in [Equation 4] becomes zero. I just need.

(Equation 4)

Therefore, the additional rotation angle θ _wx can be expressed as [Equation 5] based on [Equation 4].

(Equation 5)

The inclination i _T for Z ₂ axes in X ₂ -Z ₂ in the plane of the unit vector a ₂ in this case, the unit vector a
₂ can be expressed as [Equation 6] from the components in the X ₂ axis and Z ₂ axis directions.

(Equation 6)

As described above, when the above-mentioned main spindle rotation operation is performed within the generating motion range with respect to the tool tip position rotation angle Δq that changes due to the generating motion, the rotation angle Δq is one-to-one. , The additional rotation angle θ _wx and the inclination angle i _T corresponding to Here, the rotation angle Θ of the work spindle 110 in the conventional gear cutting device including the cradle rotating body 102 and the tilt mechanism 106.
Are the tool tip position rotation angle Δq and the cradle axis (Z
Since it is determined as the product of the rotation ratio R _e relative to the workpiece spindle 110 in _one axis), it is expressed as [Equation 7].

Equation 7

On the other hand, in the present gear cutting device, the work spindle 18 is rotated by an angle obtained by adding the above-described additional rotation angle θ _wx to the rotation angle 基 づ く based on the rotation angle Δq of the tool tip position. . That is, the rotation angle Θ _e of the work spindle 18 in the present embodiment is expressed as [Equation 8].

(Equation 8)

[0029] When the workpiece spindle in the conventional apparatus is rotated by theta, in the present embodiment, the workpiece spindle 18 is theta _e only rotated, the attitude of the tool spindle 80 at the time the inclination angle i It becomes _T.

As is clear from the above description, in the present embodiment, the bed 10 constitutes the "apparatus body" and
₂ slide 68, Y ₂ slide 52, Z ₂ slide 58,
The swivel 74 and the drive motors 54, 60, 70, 82 cooperate with each other to form a "tool spindle holding device", and the swivel 74 and the drive motor 82 cooperate with each other to form a "rotary device". .

According to the gear cutting device of this embodiment, the rotation of the tool spindle 80 and the work spindle 18 and the turning and movement of the tool spindle 80 are combined to form a beveled bevel-shaped small gear by the shaping method. Creation can be realized.

In particular, by providing the workpiece main shaft fixed upward, it is not necessary to provide a moving device or a rotating device in the dirty zone. Furthermore, by forming a chip drop hole in a portion that does not interfere with the moving device, it is easy to avoid that chips and the like accumulate on the top plate of the bed and thermally expand the device main body, thereby lowering the processing accuracy. Become.
An electric motor for rotating the work spindle, a chip collecting device, and the like can be provided in the bed, and the size of the device can be easily reduced.

In the above embodiment, the workpiece spindle is provided vertically upward, and the tool spindle is provided rotatably in the vertical plane. However, the workpiece spindle is provided horizontally, and the tool spindle is directed vertically downward. It may be rotated in a posture close to. In this case, the rotation axis of the tool spindle is disposed at a position higher than the processing position, and the rotary motor of the workpiece spindle can be disposed at a position relatively distant from the processing position. Therefore, it is easy to avoid flying chips and the like.

Although some embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is described in the above section [Problems to be solved by the invention, means for solving problems and effects]. The present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, including the described embodiment.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a gear cutting device according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing the gear cutting device shown in FIG. 1;

FIG. 3 is a front sectional view showing the gear cutting device shown in FIG. 1;

FIG. 4 is a front view conceptually showing a main part of a conventional gear cutting device.

FIG. 5 is a view conceptually showing positions of a tool and a workpiece in a conventional gear cutting device.

6 is a view taken in the direction of arrows VI-VI in FIG. 5;

FIG. 7 is a view of the position of a tool and a workpiece in the conventional gear cutting apparatus as viewed from the same direction as in FIG. 4;

8 is a view taken in the direction of arrows VIII-VIII in FIG.

FIG. 9 is a view for explaining the relationship between the conventional gear cutting device and the gear cutting device shown in FIG. 1;

FIG. 10 is another diagram for explaining the relationship between the conventional gear cutting device and the gear cutting device shown in FIG. 1;

[Explanation of symbols]

18: Workpiece main spindle 24: Top plate 26: Support member 30: Workpiece 32: Chip drop hole 36: Saw 40: Chip recovery box 42: Cutting fluid tank 50, 56, 6
6: guide rail 52: Y ₂ way sliding 58: Z ₂ way sliding 68: X ₂ way sliding
74: swivel base 76: Workpiece spindle head

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Shimazu 3-4, Akatsuki-cho, Seto-shi, Aichi F-House Co., Ltd. F-term (reference) 3C011 BB21 BB22 3C025 HH03 HH09

Claims (6)

[Claims] An apparatus main body, a workpiece headstock provided so as to be relatively immovable with respect to the apparatus main body, and rotatably holding a workpiece spindle about a central axis and axially immovable; A workpiece spindle motor, which is a numerically controllable electric motor for driving the spindle, and a straight line in three directions parallel to the X-axis, Y-axis, and Z-axis which are rotatable about the center axis of the tool spindle and are orthogonal to each other. A tool spindle holding device that holds the motion and any of the X axis, Y axis, and Z axis and a rotation axis perpendicular to the center axis of the tool spindle, and an electric motor that can be numerically controlled, respectively. An X-axis moving device, a Y-axis moving device, and a Z-axis moving device for moving the tool spindle in each of the three directions of the X axis, the Y axis, and the Z axis; a tool spindle motor that rotationally drives the tool spindle; X By controlling the electric motors of the moving device, the Y-axis moving device, and the Z-axis moving device, the workpiece spindle motor, and the tool spindle motor, the blade portion of the front gear cutting tool attached to the tool spindle can A control device for performing a motion such as teeth of a virtual bevel gear that rotates while meshing with the bevel gear attached to the work spindle, and wherein the front gear cutting tool of the device main body includes the The part located below the machining space for cutting the workpiece is
A gear cutting device configured to prevent chips generated by cutting from remaining on the device main body. 2. The apparatus according to claim 1, further comprising: a rotating device provided with an electric motor capable of numerical control, for rotating the tool spindle around the rotation axis, and wherein the control device includes the X-axis moving device and the Y-axis moving device. By controlling each electric motor of the Z-axis moving device, the electric motor of the rotating device, the workpiece spindle motor and the tool spindle motor, the blade portion of the front gear cutting tool attached to the tool spindle is 2. The gear cutting device according to claim 1, wherein the gear cutting device is configured to perform a motion of sweeping the teeth of the virtual spiral bevel gear that rotates while meshing with the spiral bevel gear attached to the workpiece spindle. 3. The gear cutting device according to claim 1, wherein said workpiece headstock rotatably holds said workpiece spindle around a substantially vertical center axis. 4. A chip drop hole for allowing chips to fall below the top plate is formed in a top plate of the apparatus main body and located below the processing space. A gear cutting device according to any one of the preceding claims. 5. The gear cutting device according to claim 4, wherein a periphery of the chip drop hole on the top plate of the apparatus main body is inclined so as to become lower as a portion closer to the chip drop hole. 6. The gear cutting device according to claim 4, wherein a chip collecting device for collecting chips dropped through the chip drop hole is provided inside the device main body.