JP3106291B2 - Numerically controlled machine tool with bar cutting function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerically controlled machine with a bar cutting function for cutting a long bar, turning the cut work, and manufacturing a plurality of products from one bar. It concerns machines.

[0002]

2. Description of the Related Art In a numerically controlled machine tool such as an NC lathe, a long bar is sometimes used as a material when a relatively small product is machined. As this type of machining method using an NC lathe, conventionally, a bar material is supplied from a rear side of the lathe to a processing portion by a bar material supply device, the bar material is rotated together with the main shaft, and the tip of the bar material is turned into a predetermined shape. In addition, a technique for cutting a product from a bar is known. Japanese Patent Application Laid-Open No. 56-76304 and Japanese Utility Model Application Laid-Open No.
A bar feeder and the like disclosed in JP-A-123601 are known. As another processing method, there is also known a technique in which a bar is cut by a dedicated device, and the cut work is supplied to a lathe by a supply device such as a robot or a loader.
Japanese Patent Application Laid-Open No. 4-46724 discloses a technique in which the bar cutting device and the work supply device are integrated into a lathe.

[0003]

However, according to the former prior art, since the bar rotates together with the main shaft, vibration occurs around the main shaft due to whirling of the bar, which adversely affects the machining accuracy. There was a point. Also,
According to the latter conventional technique, since a dedicated bar cutting device and a work supply device are required, there is a problem that the lathe is complicated, large, and expensive.

Therefore, an object of the present invention is to suppress the vibration of the main shaft and to process the workpiece with high precision, and to cut the bar by utilizing the rotation of the main shaft, thereby providing a dedicated bar cutting device and It is an object of the present invention to provide a numerically controlled machine tool having a bar cutting function, which can omit a work supply device and thus can make the entire machine compact and inexpensive.

[0005]

In order to solve the above-mentioned problems, a numerically controlled machine tool having a bar cutting function according to the present invention comprises a headstock and a through hole rotatably supported by the headstock and through which the bar is passed. Spindle, an automatic chuck attached to the tip of the spindle, a bar supply mechanism for supplying the bar to the automatic chuck through the through hole, and a gripping mechanism for gripping the tip of the bar at a position facing the automatic chuck. A gripping mechanism grips the bar and a cutting blade that cuts the bar by rotating integrally with the main spindle with the automatic chuck releasing the bar, and the automatic chuck grips the workpiece cut from the bar. And a tool post provided with a turning tool for turning in a state.

Here, preferably, the gripping mechanism is provided on the turret of the tool rest together with the turning tool so as to be able to rotate and index.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an NC lathe will be described below with reference to the drawings. As shown in FIG. 1, the NC lathe according to the present embodiment includes a bed 1, a headstock 2 fixed on the bed 1, and a saddle on the bed 1 so that the relative position between the headstock 2 and the headstock 2 can be arbitrarily changed. The tool rest 3 is provided so as to be movable via a reference numeral 25, and the stocker 4 is provided separately from the bed 1.

A spindle 5 is rotatably supported on the headstock 2 by bearings 23 (see FIG. 2), and a through hole 5a (see FIG. 2) through which a bar 6 passes is formed at the center of the spindle 5. An automatic chuck 7 for gripping a bar 6 at the tip of the spindle 5
Is attached. The tool post 3 is provided with a turret 8 so as to be rotatable. The turret 8 is provided with a gripping mechanism 9 for gripping the tip of the bar 6 and a plurality of turning tools 26 for turning a workpiece cut from the bar 6. Have been. In this case, the gripping mechanism 9 is indexed along with the turning of the turret 8 together with the turning tool 26, so that there is an advantage that a dedicated indexing mechanism is not required.

On the stocker stock 4, a receiving table 18 for receiving the base end of the bar 6, a support 17 for supporting the guide pipe 15 of the bar 6, and the bar 6 are extruded and supplied to the automatic chuck 7. A bar supply mechanism 19 is provided. The bar feeder 19 described above can be used as the bar supply mechanism 19, and a detailed description thereof will be omitted here. A chuck driving cylinder 16 is provided at the rear end of the headstock 2.

As shown in FIG. 2, the gripping mechanism 9 can be indexed to a position which is aligned with the axis of the main shaft as the turret 8 is turned. The gripping mechanism 9 includes a plurality of gripping claws 1 for gripping the bar 6.
Reference numeral 0 is provided so as to be openable and closable by an appropriate actuator (not shown) such as a cylinder or a motor, and a contact sensor 11 for detecting that the tip end surface of the bar 6 has contacted the gripping mechanism 9 is mounted.

The automatic chuck 7 is equipped with a cutting blade 13 similar to a parting tool for cutting the tip of the bar 6 and a plurality of chuck claws 12 for gripping the cut work. The chuck pawl 12 is the chuck driving cylinder 1
6 automatically opens and closes in the chuck radial direction via the draw bar 24. A draw bar 24 is firstly inserted into the through hole 5a of the main shaft 5, and a guide pipe 15 is provided inside the draw bar 24.
Further, a bar 6 is sequentially inserted inside.

The cutting blade 13 is supported inside the automatic chuck 7 so as to be slidable in the radial direction, and is separated from the bar 6 by the piston rod 14 of the hydraulic cylinder 20 and the main shaft 5.
Is driven between the center line and the position corresponding to the center line. The hydraulic cylinder 20 includes an automatic chuck 7 and oil passages 21 and
It is connected to the hydraulic unit of the NC lathe via a rotary joint at the base end of the spindle 2 and the spindle 5. The forward and backward end positions of the piston rod 14 are detected by limit switches, and these position signals are transmitted via a slip ring at the base end of the spindle 5 to the NC.
It is transmitted to the control device of the lathe. When the hollow bar 6 is processed, the position of the cutting edge of the cutting blade 13 may be controlled steplessly using a position detector different from the limit switch.

Next, the operation of the NC lathe configured as described above will be described. Prior to machining, first, in the automatic chuck 7, the chuck claw 12 is opened so that the bar 6 does not contact, and the cutting blade 13 is retracted outward in the chuck radial direction. Next, after the tool post 3 is positioned at a predetermined position with respect to the main shaft 5, the turret 8 is turned, the gripping mechanism 9 is indexed to a position aligned with the main shaft axis, and the gripping claws 10 are released.

Next, the bar 6 is supplied to the automatic chuck 7 through the guide pipe 15 by the bar supply mechanism 19.
When the tip surface of the bar 6 comes into contact with the contact sensor 11, the bar feed mechanism 19 is stopped and the gripping claws 10 are closed in response to the signal, whereby the tip of the bar 6 is gripped. You. In this state, the tool rest 3 is moved in the main shaft axis direction, and the cutting length of the bar 6 is adjusted.

Subsequently, the main shaft 5 is driven in a predetermined direction and the number of rotations, the hydraulic cylinder 20 is urged, and the cutting blade 13 is cut and moved in the radial direction of the chuck, whereby the bar 6 is cut. . Then, the cutting blade 13 is retracted, the chuck claws 12 are closed, and the work cut from the bar 6 is gripped by the automatic chuck 7. afterwards,
The gripping claws 10 are opened and disengaged from the work, the tool rest 3 is retracted from the main shaft 5, the turret 8 indexes a turning tool 26 into a machining area, and the tool 26 turns the work.

At this time, since the guide pipe 15 is supported by the support 17 of the material stocker 4 in a non-contact state with the main shaft 5 and stops inside the main shaft 5, the main shaft 5 rotates during the turning operation. Also, the bar 6 is kept stopped without rotating. Therefore, unlike the related art, the workpiece can be machined with high accuracy while suppressing the vibration of the main shaft 5.

Although the gripping mechanism 9 is provided on the turret 8 of the tool rest 3 in the above embodiment, it may be provided on the saddle 25. In the above embodiment, the cutting blade 1
Although the automatic chuck 7 is incorporated in the automatic chuck 7, the automatic chuck 7 may be provided on an end surface of the chuck driving cylinder 16 which does not engage with the main shaft 5. However, in this case, the material stocker 4
It is necessary to add a function of gripping the bar 6 to the above. In addition, the present invention is applied to a complex machining machine such as a so-called turning center in which a machining function using a rotary tool is added to a lathe, and the shape and configuration of each part are appropriately changed and embodied without departing from the spirit of the present invention. It is also possible.

[0018]

As described above in detail, according to the first aspect of the present invention, the cutting blade is rotated integrally with the main shaft while the gripping mechanism grips the bar and the automatic chuck releases the bar. The workpiece cut from the bar is gripped by an automatic chuck and processed with a turning tool, so the bar is stopped during the turning process and the vibration of the spindle is suppressed, making the workpiece highly accurate. In addition to cutting the bar by using the rotation of the main shaft, it is possible to omit the dedicated bar cutting device and the work supply device, and it is possible to configure a numerically controlled machine tool at a small size and at a low cost. To play.

According to the second aspect of the present invention, since the gripping mechanism is provided so as to be capable of turning indexing on the turret of the tool post together with the turning tool, there is an effect that an indexing mechanism dedicated to the gripping mechanism can be eliminated.

[Brief description of the drawings]

FIG. 1 shows an NC with a bar cutting function according to an embodiment of the present invention.
It is an outline view of a lathe.

FIG. 2 is an enlarged sectional view showing a main part of the NC lathe.

[Explanation of symbols]

1. Bed, 2. Spindle stand, 3. Tool post, 4. Material stocker, 5. Spindle, 5a, Through hole, 6, Bar, 7, Automatic chuck, 8, Turret , 9 gripping mechanism, 13 cutting blade, 15 guide pipe, 19
..Bar supply mechanism, 26..Turning tools.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23B 5/14 B23B 7/04 B23B 15/00

Claims (2)

(57) [Claims] 1. A headstock, a spindle rotatably supported by the headstock and having a through-hole through which a bar passes, an automatic chuck attached to the tip of the spindle, and a bar supplied to the automatic chuck through the through-hole. A bar feeding mechanism, a gripping mechanism for gripping the tip of the bar at a position opposite to the automatic chuck, and a gripping mechanism that grips the bar and rotates integrally with the main shaft in a state where the automatic chuck releases the bar. A numerically controlled machine tool with a bar material cutting function, comprising a cutting tool that cuts a bar material using a cutting tool, and a tool rest equipped with a turning tool that turns a workpiece cut from the bar material while holding it with an automatic chuck. 2. The numerically controlled machine tool with a bar cutting function according to claim 1, wherein the gripping mechanism is provided so as to be able to rotate and index on a turret of the tool post together with the turning tool.