JP2772450B2 - Non-circular workpiece machining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for turning a non-circular workpiece.

2. Description of the Related Art Conventionally, when a product Wb having a rectangular cross-sectional shape is cut from a round material Wa in an NC lathe, for example, as shown in FIG. A plurality of shape data for rough cutting is created, and the creation processing is performed by synchronously controlling the X-axis movement of the tool rest with respect to the rotation angle of the spindle.

[0003]

The machining method described in the prior art mainly involves intermittent cutting depending on the material shape and the product shape. For this reason, there is a problem that the tool life is short and cutting conditions must be set conservatively.
Further, the shape data for rough cutting must be created off-line using a personal computer or the like, and there is a problem that much time and money are wasted. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to facilitate creation of a machining program, eliminate intermittent cutting, extend tool life and improve cutting conditions. It is an object of the present invention to provide a method of processing a non-circular work that can be performed.

[0004]

In order to achieve the above object, a method for processing a non-circular work according to the present invention is to compare a radius or a lift data of a material with a lift data of a product to obtain an allowance for each angle. The maximum value of the obtained allowance is divided by the maximum depth of cut stored in advance to determine the number of cuts, the allowance for each angle is divided by the number of cuts to determine the amount of reduction for each angle per cut, The amount of reduction at each angle is sequentially subtracted from the radius or lift data of the material to obtain and store machining shape data for the number of cuts, and if necessary, reads the corresponding machining shape data into a machining program to perform turning. Is what you do.

[0005]

[Operation] The maximum machining allowance for each angle is divided by the maximum depth of cut stored in advance to determine the number of cuts, and the machining allowance for each angle is divided by this number of machining to determine the amount of reduction for each angle per cut. Ask. The first machining shape data subtracts the amount of reduction at each angle from the material radius or lift data, and the second and subsequent machining shape data sequentially subtracts the amount of reduction at each angle from the previous machining shape data. Subtract and obtain the machining shape data for the number of cuts, store it, call the machining shape data corresponding to the number of cuts into the machining program at the time of cutting, and perform synchronous control of the C-axis (spindle) and X-axis (turret) and the cutter. Creation processing is performed by cutting feed in the Z-axis direction of the table.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS This embodiment will be described below with reference to the drawings. In the NC lathe of FIGS. 1 and 2, a headstock 2 is provided on the left side of a bed 1, and a chuck 4 is fitted to a tip of a spindle 3 rotatably supported on the headstock 2. Two sets of guides in the Z-axis direction are provided on the bed 1, and a tailstock 5 is movably mounted on the lower guide. A tailstock 5 is provided on the tailstock 5 so as to be movable in the axial direction.
The center 7 is detachably attached to the tip of the. Further, a saddle 8 is movably mounted on a guide above the bed 1, and the saddle 8 is moved and positioned by a Z-axis motor 9 via a ball screw 11. A guide in the X-axis direction is provided on the saddle 8, and the tool rest 12 is movably mounted on the guide. The tool rest 12 is an X-axis motor 1
3, a turret 15 is provided on the tool rest 12 so as to be rotatable and indexable about a rotation axis in the Z-axis direction, and a plurality of tools provided on the outer periphery of the turret 15 are provided. A tool T is detachably attached to the attachment station.

The block diagram of FIG.
C control system, 16 is an input keyboard. 17 is a display CRT. Reference numeral 18 denotes an input / output interface. The material shape storage unit 19 stores the shape of the material Wa of the non-circular work W, for example, the outer diameter in the case of a round bar, and the lift data for each angle in the case of a non-circular shape. The product lift data storage unit is a part that stores lift data for each angle of the finished product Wb. The processing condition storage unit 22 is a part for storing conditions such as a maximum depth of cut and an angle. The portion for calculating the allowance of each angle is a portion for comparing the material shape with the product lift data, and calculating and storing the allowance for each angle. The number-of-cuts setting section 24 is a part for calculating the number of cuts by dividing the maximum value of the allowance by the maximum cut amount.

[0008] The reduction amount storage unit 25 for one cutting is
A part that calculates the amount of reduction for each cutting feed by dividing the allowance for each angle by the number of cuts and stores it. The machining shape data arithmetic storage unit 26 subtracts the amount of decrease for each angle from the previous data, that is, the material shape for the first time, and the immediately preceding machining shape data from the next time to obtain and store machining shape data for the number of cuts. It is. Machining program storage unit 27
Is a section for reading and storing machining shape data corresponding to the number of cuts into the machining program before the cutting feed. The servo system unit 28 controls each axis. The drive unit 29 includes a C-axis motor 31, an X-axis motor 13,
This is a part for driving the shaft motor 9.

Next, the operation of this embodiment will be described in the order of the flowchart of FIG. In step S1, the material shape is input and stored, and in step S2, the lift data of the product Wb is input and stored. Step S3
In FIG. 4, a clearance Δ for each angle θ is obtained and stored from the shape data of the material Wa and the lift data of the product Wb as shown in FIG. 4, and in step S4, the maximum clearance Δmax is divided by the previously stored maximum cutting amount. The number of cuts n is determined, and in step S5, the amount of decrease Δ for each angle θ per cut
/ N are obtained and stored. The above operation will be described using specific numerical values for easier understanding. For example, as shown in FIG. 8, when the diameter of the material Wa is φ290 mm and the product Wb is 200 mm square, if the number of cuts n is 10, Allowance Δ for each angle θ and reduction Δ /
n is as shown in the table of FIG.

Next, in step S6, machining shape data for the number of cuts is calculated and stored. In step S7, the counter N is returned to 0. In step S8, the first time stored in the machining shape data calculation storage unit 26 is performed. , Ie, the lift amount for each angle obtained by subtracting the decrease amount of each angle from the material radius is read into the machining program, and in step S9, the cutting edge of the tool T is positioned at the cutting start position. Next, in step S10, the X-axis movement of the tool rest 12 is synchronized with the main shaft 3, and at the same time, the saddle 8 is moved at the predetermined cutting feed speed by moving the saddle 8 in the Z-axis to perform cutting. One cycle of the return box motion ends. Next, in step S11, the next processing shape data, that is, the second processing shape data obtained by further subtracting the reduction amount for each angle from the first shape data is read into the processing program, and in step S12, the count N + 1 is calculated. I do.

Next, in step S13, it is confirmed whether the count N has reached the number of cuts n. If NO, the process returns to step S9, and if YES, step S14.
In step S15, the final machining shape data (lift data of the finished product Wb) is read, and in step S15, one cycle of the final finish cutting is completed. Although the present embodiment has described a method of processing a non-circular workpiece W having the same cross-sectional shape continuous in the Z-axis direction, the cross-sectional shape differs at each position in the Z-axis direction as shown in FIGS. In the case of the workpieces WA and WB, each time the Z-axis moves by a predetermined pitch, the shape data obtained by the above-described method is read to perform creation processing.

[0012]

Since the present invention is configured as described above, the following effects can be obtained. The maximum allowance among the allowances for each angle obtained by comparing the material radius and the product lift data is divided by the maximum depth of cut stored in advance to obtain the number of cuts, and the allowance for each angle is calculated by the number of cuts. Divide by one to find the amount of reduction in one cut for each angle, subtract this amount of reduction sequentially from the previous shape data to obtain and store machining shape data for the number of cuts, and if necessary, process the shape corresponding to the number of cuts Since each piece of data is read out and the non-circular workpiece is created, each piece of shape data at the time of roughing can be obtained by simple calculations, eliminating the need to take time offline to create shape data. Take time is reduced. In addition, intermittent cutting is eliminated and tool life is extended,
Cutting conditions can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an NC lathe according to the present embodiment.

FIG. 2 is a block diagram of a control system of the present embodiment including a configuration diagram of a part of an NC lathe;

FIG. 3 is a flowchart for explaining the operation of the embodiment.

FIG. 4 is an operation explanatory view of the present embodiment.

FIG. 5 is a perspective view of another work of the present embodiment.

FIG. 6 is a perspective view of another work of the present embodiment.

FIG. 7 is an explanatory view of a conventional processing method.

FIG. 8 is a cross-sectional view illustrating shapes and dimensions of a workpiece and a workpiece used as a model case of the present embodiment.

FIG. 9 is a diagram illustrating a machining allowance for each angle and a reduction amount per cut.

[Explanation of symbols]

3 Spindle 9 Z-axis motor 12 Turret 13 X-axis motor 15 Turret 19 Material shape storage unit 21 Product lift data storage unit 23 Machining calculation storage unit for each angle 24 Cutting frequency setting unit 25 Reduction amount calculation storage unit per cutting 26 Machining shape data calculation storage unit 31 C-axis motor

Claims (1)

(57) [Claims] 1. A cut-off number is obtained by comparing a radius or a lift data of a material with a lift data of a product to obtain an allowance for each angle, and dividing the obtained maximum value of the allowance by a maximum depth of cut stored in advance. , The allowance for each angle is divided by the number of cuts to determine the amount of reduction for each angle per cut, and the amount of reduction for each angle is sequentially subtracted from the radius or lift data of the material to obtain the number of cuts. A machining method for a non-circular workpiece, comprising: obtaining and storing machining shape data for each minute; and loading the corresponding machining shape data into a machining program as needed to perform turning.