JPS63174815A - Gear cutting machine - Google Patents

Abstract

PURPOSE:To enable surface roughness to be improved, by meshing a gear-shaped cutter with a workpiece gear while controlling a rotary speed and a phase angle so that a proper phase control and improvement of a cutting speed are simultaneously satisfied, in the case of a gear finishing machine. CONSTITUTION:A phase of a workpiece gear 2 and a tool 1, when they are rotated placing one tooth surface to come into contact in a normally meshing condition, is an angular velocity omega1=(r2+r1)omega2, and assuming 0 deg.. for phase displacement, the workpiece and the tool are synchronized with the phase being left as displaced by theta in a condition that the one tooth surface of the small tooth thickness tool 1 is brought into contact. This phase displacement is previously ensured by an NC unit, and a rotary speed is corrected by an NC program, distributed by a pulse distributor, given to a position control circuit, which drives servomotors 3, 4, and transmitted to the servomotors 3, 4 via a speed control circuit. Under this synchronized condition, if a slide 21 of the tool 1 is moved by a servomotor 22 so that a distance between axes obtains r1+r2, all the teeth can be cut by the predetermined dimensions.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is used in finishing machines such as gear shaving or grinding, in which force is applied while controlling the rotational speed and phase angle of a gear-shaped cutter and a workpiece gear. This invention relates to a gear processing machine that processes gears by meshing them together.

(Prior Art) In a machining method in which the contact between the workpiece gear and the tool is on one tooth surface, in order to improve the accuracy and pitch accuracy of the gear surface, the method described in Japanese Patent Publication No. 58-54935, for example, has been proposed. Control the contact pressure between the two to be constant, or
Next, drive as described in Japanese Unexamined Patent Publication No. 59-156613.

There is a method of mechanically keeping the phase of the workpiece gear and tool constant by using the internal gear number, but in the former, the machining accuracy follows the previous machining, so the pitch error improvement ability is small, and in the latter, It was difficult to maintain the ±vrt degree due to wear of the guide and gear pair, and there was a drawback that gears with ratio shafts could not be machined. Therefore, the tool and workpiece gear are each N.

There is also a third method that attempts to solve the above problem by driving the motor and performing phase synchronization.

(Problems to be Solved by the Invention) However, in this third method, the following problem arises: The rotational speed ratio of the servo motors (3) and (4) is Nl:N.

=z, :z1. Generally speaking, in order to obtain the machining speed, h>N1, so the rotation speed of the workpiece gear (2) is limited by the maximum speed of the servo motor (a). Furthermore, a position detection encoder αη detects the rotation angle of the servo motor (4), tool (1), and workpiece (2).
The rotational angular resolution is determined by the number of pulses F, , P, per rotation of , o2, but on the other hand, the pulse frequency j'1
．． No°2 is limited by the calculation speed of the No device and the encoder circuit, and this frequency J'max is several hundred K)IZ
Therefore, N≦j'max/P os.

P= 24000 pulses/rev j'max=106
If it is H2, the speed will be 500 rpm f) N, = 2sO
Orpm, N, =5N1 and Z, /Z, =1/
If 32 layers are used, N1 = about 833 rpm, and the machining efficiency is lower than the above two methods, and the cutting speed is also 14 or less, and although the pitch error can be improved by phase control,
These drawbacks are serious problems.

An object of the present invention is to provide a gear processing machine that simultaneously satisfies appropriate phase control and improvement of cutting speed.

(Means for solving the problem) Therefore, the present invention solves the problem by providing a gear processing machine as set forth in the claims. The present invention will be explained with reference to FIG. 1 showing a block diagram and FIG. 2 showing a schematic perspective view of a detailed part thereof.The present invention is based on the concept of cutting or grinding as claimed in the claims. However, at this time, the workpiece (2), which is the workpiece gear, and the tool 1 (11)
In the normal state of gear meshing (Fig. 3), the phase of is angular velocity "1 =" (rl + rl is the radius of the pitch circle), and if the phase shift at this time is θ°, then (
As shown in Fig. 4), in a state where one tooth surface of a gear-shaped tool with a thin tooth is in contact with each other, if the two are synchronized with a phase shift of θ, then w, 't=wlt10. This phase shift is N
It is secured in advance based on the command by the O device αO,
The rotational speed is commanded by the NO program so that Nyo = Z, N, and the pulse distributor (9) changes it to 21:
2. The first and second servo motors (3) (4)
) is applied to the position control circuit (7) (8) that drives the
(5) Each servo motor (
3) It is conveyed to (4). In this synchronized state, the tool (1) is slid by the third servo motor @ (Fig. 2) so that the distance between the axes becomes r, +r. If η is moved, all the teeth will be machined with the predetermined dimensions. However, since the rotational speed of the tool is controlled by the upper limit of the rotational speed due to the electrical performance mentioned above, the servo motor (4) is disconnected by the clutch α→ shown in Fig. 1, and the second servo motor (3) The chisel tool (1) is rotated (the state at this time is schematically shown in Fig. 5), and as a result, the engaged workpiece (2) is rotated, and the second
Machining was now performed at a cutting speed that far exceeded the limit on the rotational speed of the servo motor (4). Furthermore, at this time, a brake blade is installed on the workpiece support shaft (A) so as to stably contact one tooth surface. However, in this state, the main focus is on improving the surface roughness, and the dimensional accuracy has reached the target during phase control, so the accuracy of the brake torque is not so important.

(Effects of the Invention) According to the present invention, as explained above, it is possible to provide a ratio gear processing machine that simultaneously satisfies appropriate phase control and improvement of cutting speed.

Therefore, according to the present invention, it is possible to perform gear machining with high pitch accuracy using a simple mechanism, and at the same time, the cutting speed can be increased several times higher than in the case of normal NO control only, thereby improving surface roughness. In addition, there are fewer parts to wear and fewer setup changes.

Because it can be carried out by

[Brief explanation of the drawing]

Fig. 1 is a schematic block diagram showing the configuration of a gear processing machine according to an embodiment of the present invention, Fig. 2 is a schematic perspective view of a detailed part of Fig. 1, and Figs. 3 to 5 show a gear-shaped tool and a workpiece. FIG. 6 is a schematic block diagram showing the configuration of a conventional gear processing machine. l... Gear-shaped tool 2... Workpiece (workpiece gear) 3.4... Servo motor

Claims (1)

[Claims] Gear processing is a machine that grinds or shaves straight or helical gears using a gear-shaped tool, and the tool engages and rotates with the workpiece gear in contact with only one tooth surface. In a machine, a gear-shaped tool and a workpiece, which is a workpiece gear, are driven by first and second servo motors, respectively, and an NC device controls the phase angle of the two so that the phase angle thereof is always kept constant. During medium and low speed cutting, the phase angle control device performs rough machining to eliminate pitch errors, but during high speed cutting, one of the first and second servo motors for rotating the workpiece is controlled by a clutch to rotate the workpiece. A finishing machine that performs finishing machining with single tooth surface contact at a rotation speed that far exceeds the maximum rotation speed of one of the servo motors by rotating it without cutting from the support shaft and applying a constant load torque with a brake. A gear processing machine that makes it possible to improve the surface roughness of tooth surfaces.