JPH0243609Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a boring device for boring a workpiece.

<Prior art> A boring quill is attached to the main shaft which is rotatably supported on the main spindle head, and the tip of this boring quill is passed through the workpiece and is fitted and supported on the support shaft supported by the support head. A boring device is known in which a cutting tool for machining one end of a workpiece is attached to the machine, and a spindle head and a support head are moved back and forth relative to each other to bore the workpiece.

In such a known boring machine, the main shaft and the support shaft are rotationally driven by separate drive motors, so when the drive motor starts or stops, there is a gap between the main shaft and the support shaft. The difference in rotational speed causes the fitting surface to wear out, and especially when the difference in rotational speed between the two shafts is large, there is a risk that seizure may occur on the fitting surface.

Therefore, it has been considered in some cases to rotate the main shaft and the support shaft synchronously via a synchronous shaft, but such a synchronization method requires a gear connection between the main shaft, the support shaft, and the synchronous shaft. Therefore, an expensive gearbox is required, the gears cause noise, and the synchronous shaft makes maintenance difficult.

<Purpose of the invention> Therefore, the purpose of the invention is to prevent relative slippage in the mating support portion of the boring quill, even if there is a difference in rotational speed between the two main shafts, without causing the two main shafts to rotate synchronously. It is to do so.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, slide bases 13 and 14 with first and second headstocks 11 and 12 facing each other are placed on a bed 10 so as to be movable forward and backward, and drive servo motors 15 and 16 as drive sources. The feed is controlled by a feed drive device. First and second spindles 17, 18 are rotatably supported on the first and second headstocks 11, 12 on the same axis, and these spindles 17, 1
8 is adapted to be rotationally driven by first and second main shaft drive motors 19 and 20 installed on the slide bases 13 and 14 via belt transmissions 21 and 22, respectively. First spindle 1
At the tip of 7, a boring quill 23 has a plurality of boring tools T1 attached to the outer circumference at intervals in the axial direction.
is fixed to the tip of the second main shaft 18, and a tool holder 24 having one counterbore tool T2 attached to the outer periphery of the tip is fixed. A through hole is formed in the center of the tool holder 24, through which the tip of the boring quill 23 is inserted.

Further, on the bed 10, both the headstocks 1
A workpiece support 26 is provided between 1 and 12, and a plurality of machined holes W are formed on this workpiece support 26.
A workpiece W having a counterbore W2 and a counterbore W2 is positioned and clamped.

Although not shown, the boring quill 23
In order to avoid interference between the machining hole W1 of the workpiece W and the cutting tool T1 when the workpiece W is inserted into the workpiece W, a lift device that lifts the workpiece support 26 upward by a small amount is provided, and the first spindle 17 byte T
A fixed position stop device is provided for stopping the device at a certain angular position with 1 facing upward.

The second main shaft 18 has, as shown in FIG.
The rotation supporter 30 is rotatably supported by a bearing 31 on the same axis as the main shaft 18, and is provided with some rotational sliding resistance by a seal ring 32. A fitting hole 33 is formed in the rotation supporter 30 in the axial direction, and a narrow diameter portion 34 formed at the tip of the boring quill 23 is inserted into the fitting hole 33.
are fitted and supported so that they can rotate and slide relative to each other. An engagement groove 35 is formed in the fitting hole 33, and an engagement member 36 that engages with this engagement groove 35.
is pivotally supported to be slidable within the diameter plane of the narrow diameter portion 34 so as to be able to protrude and retract from the outer circumferential surface of the narrow diameter portion 34, and protrude from the outer circumference of the narrow diameter portion 34 due to the repulsive force of the spring 37. biased in the direction.

Since the device of the present invention is configured as described above, first, the workpiece support 26 is lifted upward by a minute amount by a lift device (not shown), and the first headstock 11 is moved to a predetermined position by the servo motor 15. The boring quill 23 is fast-forwarded to 300 degrees and stopped at a certain angular position.
mated to. At the same time, the second headstock 12 is rapidly advanced by the servo motor 16 to a predetermined position. Thereafter, the workpiece support 26 is lowered by a small amount by the lift device.

Subsequently, the spindle drive motors 19 and 20 are started to rotationally drive the first and second spindles 17 and 18, and both headstocks 11 and 12 are advanced at the cutting feed rate to cut the machined hole W1 of the workpiece W. , counterbore W
2 are bored using bits T1 and T2, respectively. When machining of the machined hole W1 and the counterbore hole W2 is completed, the second headstock 12 is retreated and the cutting tool T2 is removed from the counterbore hole W2. In this state, the main shaft drive motors 19 and 20 are stopped, and the first
The main shaft 17 is stopped at a fixed angular position by a fixed position stopping device (not shown). In addition, the workpiece support 2
6 is lifted upward by a minute amount again, and then the first headstock 11 is retreated and the boring quill 23 is removed from the fitting hole 33 of the rotation supporter 30 and the workpiece W.

By the way, when the spindle drive motors 19 and 20 are started and the first and second spindles 17 and 18 are rotationally driven, it is necessary to maintain the same rotational speed curves at the time of startup of both spindles due to the load. difficult,
Although it is inevitable that there will be a relatively large difference in rotational speed between the two main shafts 17 and 18, in the present invention, the tip (small diameter portion 34) of the boring quill 23 is connected to the bearing 31 on the second main shaft 18. Therefore, it is fitted and supported by the rotation supporter 30 which is rotatably supported, and when the tip of the boring quill 23 and the rotation supporter 30 rotate relative to each other, the engagement member 36 engages with the engagement groove 35. After that, the boring quill 23 and the rotation supporter 30 rotate together. Therefore, even if a large rotational speed difference occurs between the two main shafts 17 and 18 to which the boring quill 23 and the tool holder 24 are attached, there will be almost no rotational slippage at the fitting support portion of the boring quill 23, and no seizure will occur. This will prevent wear on the mating surfaces.

<Effects of the invention> As described above, the present invention has a boring quill for machining a workpiece and a cutting tool holder attached to two main spindles, and a rotation mechanism that fits and supports the tip of the boring quill attached to one of the spindles. The supporter is rotatably supported on the other main shaft, and the rotary supporter and the boring quill are rotationally connected by an engagement member, so both main shafts are rotated by separate drive motors. Even if a difference in rotational speed occurs between the two when driven, the rotational supporter within the rotationally driven main shaft is rotated relative to each other, so rotational slippage does not occur in the fitting support portion of the boring quill. It is possible to prevent seizure and abrasion of the fitting support part, maintain high support accuracy of the boring quill over a long period of time, and also eliminate the negative effects caused by synchronously rotating both main shafts. This has the advantageous effect of eliminating this problem in practice.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view showing the entire boring machine, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 10... Bed, 11, 12... Headstock, 1
7, 18... Main shaft, 19, 20... Main shaft drive motor, 23... Boring quill, 24... Bit holder, 30... Rotation supporter, 33... Fitting hole, 3
5...Engagement groove, 36...Engagement member, T1, T2...
...Part-time job, W...workpiece.

Claims (1)

[Scope of utility model registration request] First and second headstocks are supported on the bed so as to be movable and retractable, facing each other; a main spindle, first and second drive motors for rotationally driving the first and second main spindles, and a cutting tool fixed to the tip of the first main spindle and attached to the outer periphery for boring the workpiece. A boring quill, a cutting tool fixedly attached to the tip of the second spindle and used to countersink one end of the workpiece are attached to the outer periphery, and a through hole is formed in the center through which the tip of the boring quill is inserted. a rotation supporter that is rotatably supported on the second main shaft and has a fitting hole formed therein to fit and support the tip of the first boring quill in a relatively rotatable and relatively slidable manner during processing; Boring processing characterized by comprising the rotation supporter and an engagement member provided at the fitting support portion of the boring quill to rotationally connect the rotation supporter and the boring quill by relative rotation between the two. Device.