JPH0722849B2 - Processing equipment by non-circular gear creation method - Google Patents

Description

TECHNICAL FIELD The present invention is used in the technical field of gear machining, and particularly relates to machining non-circular gears (gears whose pitch lines are not circular).

(Prior Art) With the recent development of computers, the design and processing of non-circular gears have come into practical use. (See page 38 and subsequent pages of the 2nd Design Automation Engineering Conference). However, in the processing of non-circular gears, even if an attempt is made to use a forming tool, the shape is different for each tooth, which is not practical.

Further, Japanese Patent Laid-Open No. 49-132694 describes a machining device for non-circular gears which is numerically controlled. However, this device is dedicated to elliptical gear machining, and the machining device itself requires a dedicated format, which is not versatile.

On the other hand, when the creation method is used, not only can a gear tooth profile with arbitrary backlash or dislocation be machined without changing the tool shape, but the module and pressure angle can be changed even if the number of teeth of the gear to be machined changes. If they are the same, there is an advantage that the same tool shape may be used.

However, if a pinion cutter is used as a tool, it will be shaped, and the cutting direction will be limited to one direction. Therefore, a relieving operation is required, and a constant linear movement amount must be given to the normal direction of the gear pitch line at the contact point between the gear pitch line and the pinion cutter pitch line. Therefore, linear axis operation and rotary axis operation for escape direction angle control are also necessary for escape operation,
The operation control becomes complicated. Therefore, in this case, the structure or operation control of the machine tool is complicated. In addition, the pinion cutter itself has a complicated shape,
There is an envy that makes it expensive.

(Problems to be Solved by the Invention) The present invention solves the problem that a machine tool having a unique control function corresponding to the creation method is required in machining a non-circular gear even if the creation method is applied. It is what

(Means for Solving Problems) Means for solving the above problems will be described below with reference to the drawings.

The processing apparatus of the present invention mainly comprises a machine tool 1 and a computing means 2. The machine tool 1 includes a work holding means 4 for holding a work WO on a shaft 3 having a variable rotation angle A (a rotation angle amount of the work WO), and a tool holding means for rotatably holding a rack-shaped tool T for the work WO. 5 and 5. further,
The mutual position between the work WO and the rack-shaped tool T in a plane perpendicular to the axis 3 (for example, X and Y perpendicular to each other).
The position in the direction) is variable. And the angle A and the mutual position are device controlled. The computing means 2 computes the command value of the angle A and the mutual position so that the pitch curve P ₁ of the non-circular gear to be created and the pitch line P ₂ of the rack type tool make rolling contact, and the machine tool 1 Is output to.

(Operation) Next, the operation of the above means will be described.

When the work WO turns around the axis 3 by an angle A, the mutual position between the corresponding rack-shaped tool T and the work WO is controlled, whereby the pitch curve P _{1 of the} gear to be created on the work WO. And the pitch line P ₂ of the rack tool T are subjected to mutual movement so as to make a rolling contact, thereby creating a tooth profile along the non-circular pitch curve P ₁ .

(Example) Hereinafter, the Example of this invention is described in full detail.

In the machine tool 1, the shaft 3 of the work holding means 4 is supported in the horizontal direction, and the rotation angle A is controlled by the servomotor 4a.

The tool holding means 5 includes a horizontal shaft 5a for mounting a rack-shaped tool T (a rotary tool for grinding having only one tooth of a rack in this embodiment), a power means 5b for rotating the shaft 5a, The power means 5b is configured so that the tool T can be retracted and retracted in the direction of the shaft 5a, that is, in the same direction (X direction) as the pitch line P ₂ of the rack-shaped tool T, and the position of the tool T in the X direction is variable. Is attached. Further, the power means 5b is held by a holding frame 5d so as to be able to move up and down, and a servomotor 5c is provided on the holding frame 5d. The operation of the servomotor 5e causes the power means 5b, that is, the vertical position of the tool T (Y direction position) Is variably configured.

As the machine tool 1, for example, a commercially available CNC
(Computerised Numerical Control) An ultra-precision surface grinder can be used.

Although not shown in detail in the machine tool 1, the creation motion of the rack-shaped tool T, that is, the rotation angles A and X of the work WO,
A linear reciprocating mechanism (in the same direction as the shaft 3) asynchronous with position control in the Y direction is provided. The stroke of this reciprocating motion is configured to cover at least the margins at both ends in the thickness of the workpiece WO to be processed.

The computing means 2 is composed of a computer. The control program will be described with reference to FIG. 2 and 5, O is the equation r = f
It is the origin of (θ).

(1) First, the equation r = f (θ) of the pitch curve of the non-circular gear to be machined and other necessary information (for example, module m, tool tip coefficient C, clearance x, tool pressure angle α, etc.) are input ( Step S ₁ ).

(2) The mutual position between the work WO of the work holding means 4 and the tool T of the tool holding means 5 is position-controlled (in this embodiment, the tool T side is position-controlled), and the start point of one cycle of gear machining (the third). Position command output (step S ₂ ) so that the position is located at the position (T 'in the figure).

(3) Is calculated (step S ₃ ).

(Where ρ is the radius of curvature of the pitch curve P ₁ ) (4) From the equation r = f (θ) (the same applies to the following calculations), Is calculated. (Step S _4).

Here, the distance from the beginning to the n-th tooth (n) on Ln = pitch line P ₂ (that is, in FIG. 5, the starting point of the pitch line P 2 of the tool T corresponding to the starting point P 10 of the pitch curve P 1 of the gear is The length of the pitch line P2 from the state where it coincides with the starting point P10 of the pitch curve P1 to the n-th tooth when both pitch lines P1 and P2 make rolling contact is Ln.).

(5) Next Is calculated (step S ₅ ).

Here, Lθ = perimeter up to the angle θ of the pitch curve P ₁ (second
Referring to FIGS. 5 and 5, the circumference from the starting point P10 corresponding to the first tooth of the pitch curve P1 to P1n corresponding to the nth tooth, the pitch curve P1 and the pitch line P2 are in rolling contact. Note that you do. ). (6) Is calculated (step S ₆ ).

Here, ψ is a tilt angle indicating the normal direction of the pitch curve at the angle θ, that is, the normal direction at the point B on the pitch curve P1 at the angle θ, the origin 0 of the equation r = f (θ), and It is an angle formed by a straight line connecting point B.

(7) From the results of Ln, Lθ and ψ, X = Ln−L
Calculate θ + r.sin ψ. (Step S _7).

(8) Further calculate Y = r.cos θ (step
S ₈ ).

(9) Furthermore, A = θ−ψ is calculated (step
S ₉ ).

(10) for outputting the computed X, Y and A (step S _10).

(11) It is determined whether or not the amount of X change has reached 2 W (whether or not one cycle has ended) (step S ₁₁ ).

(12) Step S ₁₁ in a incomplete machining of one cycle if NO, the proceed further control to processing returns to step S _4. If YES in step S ₁₁ all machining of the workpiece WO termination determines whether (step S _12).

(13) Back Further If NO in the step S ₁₂ to step S ₂ to perform the processing of the next cycle. Y in step S ₁₂
If ES, terminate the program.

In addition to the above, the embodiment of the present invention can be modified as described below.

(1) In the machine tool 1, the work WO of the work holding means 4 does not move, and the tool T of the tool holding means 5 is X and Y.
In addition to moving in the direction, the work WO on the work holding means 4 side may be movable. Both may be movable.

(2) The machine tool 1 can be implemented as long as it can control the rotation angle A and the positions X and Y in addition to the surface grinder.

(3) The rack-shaped tool T may have not only one tooth of the rack but also a plurality of teeth arranged in parallel. The tool T is
It may be a grinding tool or a cutting tool. When machining with these tools, the finishing allowance may be divided into plural times and not finished at once.

(4) The X direction is the direction of the axis 5a, that is, the rack type tool T
The direction of the pitch line P ₂ may be the same as that of the pitch line P ₂ of FIG. In this case, the arithmetic means 2 may be provided with means for converting the intersecting rectangular coordinate value into a rectangular coordinate value including a straight line parallel to the pitch line P ₂ .

(5) Furthermore, the mutual position of the work WO of the work holding means 4 and the tool T of the tool holding means 5 is necessarily controlled by a Cartesian coordinate system on a plane perpendicular to the axis 3 in the machine tool 1. Instead, it may be controlled by another coordinate system (for example, a polar coordinate system). In this case, the calculation means 2 requires a means for coordinate conversion.

(Effects of the Invention) As described above, the processing apparatus of the present invention is based on the creation method using the rack-shaped tool, so that the tool shape is simple and the accuracy is easy to obtain, and the tool shape can be adjusted against any backlash or dislocation. Not only is it possible without changing it, but since the rack type tool can be formed as a rotary tool whose cross-sectional shape is formed in a straight line, grinding and stone can be applied at times, and only the cutting can be performed by the gear creation method. In addition to having the advantage that grinding can be performed easily, it does not require a special machine tool capable of complicated operation control like when using a pinion cutter as a creation method, it is a machine tool with simple operation It has the effect of Further, a non-circular gear having an arbitrary shape defined by the pitch line r = f (θ) can be targeted.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings each show an embodiment of the present invention. FIG. 1 is an overall perspective view, FIG. 2, FIG. 3 and FIG. FIG. 4 is a flow chart of the program, showing the coordinate system for fixing the work. 1 ... Machine tool, 2 ... Calculation means, 3 ... Axis, 4 ... Work holding means, 5 ... Tool holding means, A ... Rotation angle,
T: rack type tool, WO: workpiece, X and Y: control direction.

Claims (1)

[Claims] 1. A machining device by a method of creating a non-circular gear, comprising a work holding means for holding a work on a shaft having a variable rotation angle A, and a tool for rotatably holding a rack-shaped tool for this work. At least holding means is provided, and between the work and the rack-shaped tool, an X-axis in the same direction as the pitch line of the rack-shaped tool in a plane perpendicular to the axis, and a Y-axis perpendicular thereto. A machine tool having a mutual position variable in the axial direction and capable of numerically controlling the mutual position in the rotation angle amount A and the XY direction is provided, and a command of the rotation angle amount A and the mutual position XY is given to the machine tool. A calculation means for calculating and outputting the position is provided, and the calculation means is a polar coordinate equation r of the pitch curve of the non-circular gear.
= Distance from the first tooth to the nth tooth on the pitch line of the tool from f (θ) Perimeter of pitch curve up to angle θ of non-circular pitch curve And the tilt angle indicating the normal direction of the pitch curve at the angle θ Means for calculating and X = Ln−Lθ tens r · sin ψ, Y =
A means for calculating r · cos ψ and A = θ−ψ is provided, and relative motion is applied so that the pitch curve of the non-circular gear and the pitch line of the rack-shaped tool make rolling contact. , Processing equipment by non-circular gear creation method.