JPH0132021B2 - - Google Patents

Description

Detailed Description of the Invention This invention is a 4-axis lathe equipped with two independently movable tool rests, and the purpose of this invention is to divide the load equally between the two tool rests for the same process part, which is the purpose of reducing machining time. This invention relates to a numerical control device that improves the processing of balanced cuts in which cutting is done in synchronization.

Conventionally, as a balance cutting method, there has been a first balance cut in which two tool rests start machining at the same time, and the relative positions of the two tool rests and the workpiece are as shown in FIG.

In Fig. 1, 1 is the first turret, 2 is the second turret.
3 is the workpiece.

FIG. 2 shows an example of a tool path during balance cutting, where P and Q indicate the tool paths of the first and second tool rests 1 and 2, respectively, and L indicates the center line of the workpiece 3. A solid line indicates a cutting portion, and a broken line indicates a non-cutting portion such as rapid feed.

Figures 3a and 3b show the machining division in one machining process. Figure 3a is a developed view of Figure 3b, and the tool path of the first tool post 1 is A ₀ →A ₁ (A ′ ₁ )→A ₂
(A′ ₂ ) → A ₃ , the cutting part is the shaded part,
The tool path of the second turret 2 is B ₀ →B ₁ (B′ ₁ ) →B ₂
The cutting part is a blank part.

FIG. 4 shows a comparison of the cutting conditions in the case of one tool post and the case of the first balance cut.

Next, the operation will be explained. In the conventional first balance cut, the tool paths of the first tool rest 1 and the second tool rest 2 are symmetrical with respect to the center line L of the workpiece 3, as shown in FIG. The first tool rest 1 and the second tool rest 2 start machining at the same time and cut in synchronization by using a signal generated every rotation from an encoder attached to the main shaft or by an equivalent method. Therefore, as shown in Fig. 1, the first tool rest 1 and the second tool rest 2 are always connected.
The position is symmetrical with respect to the center line L of the workpiece 3. Furthermore, since the load is equally divided between the two tool rests, the feed rate can be doubled compared to when there is only one tool rest, and the cutting time can be reduced.

The conventional first balance cut is constructed as described above, and as shown in Fig. 3a, one cutting surface is divided and cut by two tool rests. Tools with different cutting edge shapes cannot be used for the tool rest 2 and the tools must have exactly the same cutting edge shape, and even if tools with the same cutting edge shape are used, the installation conditions of the tools cannot be used. If the material is different, there are drawbacks such as the possibility of leaving uncut parts.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and the cutting depth of one tool post is twice that of the other, and machining is started after delaying the rotation given by the parameter. By adding a second balance cut in which one turret handles one cutting surface, the restrictions for executing balance cut can be relaxed and the utilization of balance cut can be increased. The purpose of this invention is to provide a numerical control device for an enhanced four-axis lathe. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows the relative positions of the two tool rests and the workpiece when performing the second balanced cut of the present invention.

FIG. 6 shows an example of the tool path when executing the second balance cut, in which the solid line shows the cutting part, the broken line shows the non-cutting part such as rapid traverse, and the two-dot chain line shows the cutting part of the mating tool.

FIG. 7 shows a comparison of cutting conditions in the case of one tool post and the case of a second balance cut.

FIG. 8 is a block diagram showing the configuration of an embodiment of the present invention, and shows an example of a configuration that allows selective use of the first balance cut and the second balance cut added according to the present invention. In this diagram,
11 is a central processing unit (hereinafter referred to as CPU) that decodes a given instruction and processes it; 12, 12'
is a motion control unit (hereinafter referred to as "motion control unit") which creates movement data based on the commands of the CPU 11.
(referred to as MCU), 12 is a start-up control device 1
MCU 12' for the first turret with 2a is
The MCU 13, 13' for the second turret equipped with the start standby control device 12b is the MCU 12, 1
Servo processing device 14a, 14 that controls servo output based on the movement data created in step 2'
b, 14a', 14b' are the servo processing devices 13,
Amplifiers 15a, 15b, 15a', and 15b' which amplify the servo output output from 13' are servo motors.

FIG. 9 is an example of a flowchart for selectively using the first balance cut and the second balance cut of the present invention. In this figure, ~ indicates each step.

The relative positions of the first tool rest 1 and the second tool rest 2 during cutting using the second balance cut of the present invention are shown in FIG. Second turret 2
For example, the depth of cut is 2 compared to the first tool rest 1.
After the first tool post 1 starts cutting, it waits for a designated rotation and then starts cutting.

First turret 1 in second balance cut
The tool path of the second tool post 2 is as shown in Fig. 6, and each tool path is every other tool compared to the path when there is one tool post, so the tool path is halved, and the tool path is reduced by half. Therefore, it becomes possible to shorten the cutting time.

Next, the operation of the apparatus which selectively uses the two types of balance cuts shown in FIG. 8 will be explained using the balance cut flowchart shown in FIG. 9.

When a balance cut is specified, in the case of the first tool rest 1, whether it is the first balance cut or the second balance cut, the start control device 12a attaches the cut to the main shaft. Machining is started using the signal generated from the encoder every rotation. In the case of the second turret 2, the type of balance cut is determined, and in the case of the start start standby control device 12b, if the first balance cut is specified, the encoder is used to determine the type of balance cut. Processing is started using the generated signal, and in the case of second balance cut specification, processing is started using the signal after waiting for the signal a specified number of times.
.

In the above embodiment, the synchronized and simultaneous start of the first balance cut was performed using a signal issued every rotation from the encoder attached to the main shaft. It is also possible to check the synchronization and start synchronization.

As explained in detail above, according to the present invention, in the case of the conventional first balance cut, the depth of cut of the two tool posts is the same, and the tools of the two tool posts are used to form the same machining surface. However, according to the second balance cut of the present invention, the two tool rests have different depths of cut, and therefore, Since the machining surfaces are different, there is a greater degree of freedom in the shape of the cutting edge of the tool and the conditions for installing the tool, and restrictions on the material can also be significantly reduced, which has the effect of increasing the utilization of balance cutting.

[Brief explanation of drawings]

Figure 1 shows the relative positions of the first and second turrets when performing the conventional first balance cut, and Figure 2 shows the tool path during the first balance cut. Figure 3 is a diagram showing the processing division of the two turrets in the first balance cut, Figure 4
The figure shows a comparison of the cutting conditions in the case of one tool post and the case of the first balance cut, and Fig. 5 shows the cutting conditions of the first tool post and the second tool post when performing the second balance cut in this invention. A diagram showing the relative position with
Figure 6 is a diagram showing the tool path during the second balance cut, Figure 7 is a diagram comparing the cutting conditions in the case of one tool post and the case of the second balance cut, and Figure 8 is a diagram of the present invention. FIG. 9 is a block diagram showing the configuration of one embodiment, and a flowchart thereof. In the figure, 1 is the first tool rest, 2 is the second tool rest,
12a is a start start control device, 12b is a start start standby control device, 13 and 13' are servo processing devices, 1
4a, 14b, 14a', 14b' are amplifiers, 15
a, 15b, 15a', 15b' are servo motors. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 Two turrets each capable of moving in two directions
An individually equipped 4-axis lathe, which is equipped with an encoder attached to the main shaft that rotates the workpiece, and a start-start standby control device that calculates the start timing using a signal emitted from the encoder every time the work rotates, Furthermore, when performing a balance cut in which the same process part is cut in synchronization by dividing the load equally between two tool holders, the first balance cut and one of the turrets start machining at the same time. A numerical control device characterized by comprising means for selecting one of the second balance cuts for starting machining by slowing down the rotation of the table by a specified amount.