JPH0356858B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support structure for a tool rest of a compound lathe.

Fig. 1 is a diagram showing an example of a compound lathe, where 1 is a bed, 2 is a chuck attached to the main shaft, and 3 is a chuck attached to the bed 1 so as to be slidable in the direction of the main shaft (perpendicular to the plane of the drawing). 4 is a machine base mounted on the cross slide 3 so as to be slidable in the left and right direction in the figure; 5 is a tool rest mounted on this machine base 4; 6 is a cross slide mounted on the machine base 4;
is an electric motor for sliding the machine base 4. The compound lathe is equipped with a tool mounting shaft 8 that can rotate the attached tool 7, and in addition to turning with a cutting tool or the like, various types of processing can be performed with the rotary tool 7. There are known tools that use a turret to change tools, and tools that are equipped with an automatic tool changer. 9 in the figure is an electric motor for rotating the tool mounting shaft 8.

By the way, in conventional compound lathes, the tool rest 5 is either fixed to the machine stand 4 or is rotatably mounted, and is rotated in a direction perpendicular to the main spindle and the tool axis (vertical direction in Fig. 1; hereinafter referred to as the Y-axis direction). ) is not permitted. Therefore, for example, when a milling cutter is attached to the tool mounting shaft 8 and a keyway is machined, the width of the keyway to be machined is determined by the outer diameter of the milling cutter, and when the cutter is worn out, the keyway is machined. The width of the keyway also became narrower, and even if I wanted to widen the width of the keyway a little, I had to replace the cutters one by one.

An object of the present invention is to provide a support structure for a tool rest that can give a minute displacement to the tool rest in the Y-axis direction.

To explain using the reference numerals of the illustrated embodiments, the tool rest support structure of the present invention is used in a compound lathe equipped with a tool rest 5 having a rotating tool mounting shaft 8 as shown in FIG. The tool rest 5 is connected to the tool rest 5 by pillars 10 and 34 in a direction perpendicular to the tool mounting shaft 8, and the tool rest 5 is supported so as to be able to move minutely in the axial direction of the pillar. A cylindrical hydraulic chamber 1 with a cross-sectional shape symmetrical to the axis of
1 and 35, and is provided with a feedback control device that controls the pressure of the hydraulic oil supplied to this hydraulic chamber by referring to the displacement in the axial direction of the columns 10 and 34 of the tool rest 5, and controls the pressure in the hydraulic chamber. The resulting simple tensile elastic strain in the axial direction of the struts 10 and 34 is utilized to cause the tool post 5 to undergo minute displacement in a direction orthogonal to the tool mounting shaft 8.

By making it possible to give the tool post 5 a minute feed in the Y-axis direction with this structure, when machining the aforementioned keyway, you can also give the cutter a feed in the width direction of the keyway. Dimensions can now be corrected, the complexity of tool replacement can be eliminated, and machining accuracy can also be improved.

According to the above structure, when the tool mounting shaft 8 is displaced in the Y-axis direction, it is not displaced at all in directions other than the Y-axis, making it possible to accurately apply a desired displacement to the cutter 7.

Figures 2 and 3 are diagrams showing an embodiment of the present invention, Figure 2 is a diagram showing the detailed structure of the tool post support section, and Figure 3 is a diagram showing the pressure oil supply device and its control system. be. 10 in Fig. 2 is a support, and this support 10
Its lower end is fastened to the machine stand 4, and its upper end is fastened to the tool rest 5. The tool rest 5 is provided with a cylindrical recess centered around the support column 10, and a hydraulic chamber 11 is formed therein. Reference numeral 12 designates a washer-like spring plate, and the inner diameter part of this spring plate 12 is clamped between the lower end of the column 10 and the machine base 4 and fixed to the machine base 4 side, and the outer diameter part forms the hydraulic chamber 11. The lower end of the tool rest 5 and the presser foot 13 are clamped and fixed to the tool rest 5 side. Reference numeral 15 denotes a sleeve fitted into the cylindrical recess formed in the tool rest 5;
Reference numeral 5 is provided to prevent the pressure of the hydraulic oil in the hydraulic chamber 11 from directly acting on the tool rest 5 made of cast metal. For the same reason, the upper end of the hydraulic chamber 11 is formed with a cap 16,
The column 10 and the tool rest 5 are fixed via this cap 16. Therefore, when the tool rest 5 is made of a welded structure, there is no need to provide the sleeve 15, and the column 10 can be directly fixed to the tool rest 5. 17 and 18 are pressure oil supply holes provided in the machine base 4 and the support column 10, 19 and 20 are liquid sealing devices,
21 indicated by an imaginary line is a workpiece.

When pressurized oil is supplied to the hydraulic chamber 11 of the support structure configured in this manner, the pressure of the pressurized oil causes tensile stress in the axial direction to be generated in the column 10, and due to the elastic strain of the column 10 caused by this, Since the tool post 5 is slightly displaced upward in FIG. 2, it is possible to give the tool mounting shaft 8 a small amount of feed in the Y-axis direction. The spring plate 12 is provided to allow minute displacement between the machine base 4 and the tool rest 5 in the Y-axis direction, and to ensure rigidity against external forces acting perpendicularly to the axis of the support 10.

The pressure oil supply device to the hydraulic chamber 11 and its control system are shown in FIG. 3, in which 22 is a cylinder of the pressure oil supply device, 23 is a plunger that moves forward and backward within the cylinder 22, and 24 is a plunger. 23 is a screw rod formed integrally with the screw rod 24, 25 is a gear screwed into the screw rod 24, 26 is a gear meshed with the gear 25, 2
7 is a DC motor that drives the gear 26, and 28 is a hydraulic pipe. The DC motor 27 rotates under servo control by a control device to be described later, and a gear 25 is supported by a frame (not shown) via a bearing 29.
is rotated, the plunger 23 is moved back and forth to change the pressure of the hydraulic oil supplied to the hydraulic chamber 11, and the amount of displacement of the tool rest 5 in the Y-axis direction is changed.

The amount of displacement of the tool post 5 is detected by a differential transformer 30 and transmitted to the differential amplifier 3 via an isolation amplifier 31.
2, and on the other hand, command data given from an NC device or other command device (not shown) is given to the differential amplifier 32 via a DA converter, and the servo amplifier controls the DC motor 27 based on the difference signal. do. When the output of the differential amplifier 32 falls within a certain tolerance, a match signal is output from the comparator 33 to the command device, and the Y-axis direction position of the tool rest 5, that is, the tool 7, is set to the commanded position. is reported to the command device.

In the embodiment shown in FIG. 2, a hydraulic chamber 11 is formed around a support 10, but as shown in FIG.
Of course, it is also possible to form the hydraulic chamber 35 inside the support column 34 by connecting the two. Here, pillar 3
Needless to say, the upper end of 4 is fastened to the tool rest 5, and the lower end thereof is fastened to the machine stand 4.

According to the support structure described above, for example, by generating a hydraulic pressure of about 700 kg/cm ² by the plunger devices 22 and 23, the tool post 5 can be displaced about 0.3 mm in the Y-axis direction without losing its rigidity. It is possible to correct the wear amount of the rotary tool 7, correct the fitting dimensions of keyways, etc., or perform rough cutting and finishing cutting with the same tool by small feed in the Y-axis direction. Machining becomes possible, the time required to change tools is shortened, and higher precision machining is also possible.

Furthermore, according to the structure of the present invention, even if the blade 7 is displaced in the Y-axis direction, the blade 7 is not displaced at all in other directions, so that the workpiece can be accurately machined into a desired shape.

[Brief explanation of drawings]

Fig. 1 is a side view of a compound lathe seen from the tailstock side, Fig. 2 is a partially sectional side view showing details of the tool post support structure of the present invention, and Fig. 3 is a hydraulic generator and its control system. 4 are partially sectional side views showing other embodiments of the tool post support structure of the present invention. In the figure, 1 is a bed, 3 is a cross slide, 4 is a machine stand, 5 is a turret, 7 is a rotary tool, 8 is a tool mounting shaft, 10 and 34 are columns, 11 and 35 are hydraulic chambers, 1
2 is a spring plate, 13 is a presser foot, 17 and 18 are pressure oil supply holes, 21 is a workpiece, 22 is a cylinder, 23 is a plunger, 27 is a DC motor, 28 is a hydraulic pipe,
30 is a differential transformer, and 32 is a differential amplifier.

Claims (1)

[Scope of Claims] 1. In a compound lathe equipped with a tool rest 5 having a rotary tool mounting shaft 8, the tool rest 5 is provided with a support in a direction perpendicular to the tool mounting shaft 8 on a machine stand 4 that slides on a cross slide 3. 10, 34, and the tool rest 5 can be moved minutely in the axial direction of this support.
A cylindrical hydraulic chamber 11, 35 having a cross-sectional shape symmetrical to the axis of the column is formed inside or around each column, and the pressure of the hydraulic oil supplied to this hydraulic chamber is transferred to the column 10, 35 of the tool post 5. A feedback control device is provided for controlling the axial displacement of the column 1 caused by the pressure in the hydraulic chamber.
A support device for a tool rest in a compound lathe, characterized in that a minute displacement is caused in the tool rest 5 in a direction perpendicular to a tool mounting shaft 8 by using an axial simple tensile elastic strain of 0.34. 2. The tool rest support device according to claim 1, wherein the machine stand side end of the support and the tool rest are connected by a spring plate 12.