JP2936297B2 - NC boring equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an NC boring apparatus, and more particularly, to an NC boring apparatus suitable for machining a work in which there is a narrow portion between the machining portions of the work and it is difficult to perform boring from one direction. About.

[0002]

2. Description of the Related Art A boring apparatus is used for processing an inner surface of a hollow workpiece, and generally has one tool head for holding a tool for processing a workpiece.
Many are processed from one direction. By the way, for example, in a workpiece such as a bearing fitting portion on the inner surface of a hub for mounting a wheel in an automobile, it is difficult to perform machining from one direction with a narrow constricted portion therebetween. I can not use it.

[0003] For this reason, in the case of processing a work in which a narrow portion exists between the inner surface processed portions, such as a boring process of the bearing fitting portion of the hub, conventionally, a horizontally opposed type is used. Boring equipment is used. In this device, mutually independent units each having a tool head are arranged opposite to each other across the work, and each unit is driven and each unit is approached from both sides of the work in the work direction. Boring processing is performed on the processing portions on both sides of the constricted portion.

[0004]

However, in such a horizontally opposed boring apparatus, the units disposed opposite to each other are independent of each other and the tool heads are also independent, so that the tool heads are coaxially high. It is difficult to place with accuracy. For this reason, it is difficult to increase the accuracy of the coaxiality of the processing portion of the work more than ever.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has an NC boring apparatus capable of easily processing a workpiece having a narrow constricted portion between processing sections and difficult to simultaneously process from one direction with high coaxiality accuracy. The purpose is to provide.

[0006]

For this reason, the NC of the present invention
The boring device is provided at a substantially central portion on the base and holds a work to be processed, and is disposed to face the work holding portion so as to be movable toward and away from the work holding portion. A first and second unit section provided on the base, and first and second unit driving means for slidingly driving the first and second units, respectively, wherein the first unit section A hollow first spindle rotatably supported by the housing and having a hollow first tool head for holding a processing tool concentrically and removably attached to an end of the workpiece holding portion on the side of the workpiece holding portion; A hollow second spindle that penetrates the first tool head and is integrally rotatable and axially movable with respect to the first spindle and the first tool head; and a second spindle that is axially movable relative to the second spindle. A drawbar, a drawbar driving means attached to the end of the second spindle opposite to the work holding portion side for slidingly driving the drawbar with respect to the second spindle, and the second spindle being connected to the first spindle and the first spindle. A second spindle driving unit that slides and drives the tool head; and a first spindle driving unit that rotationally drives the first spindle.
The second unit portion is clamped by the tip of the draw bar, is disposed opposite to the first tool head, and detachably holds a second tool head for holding a processing tool that can be fixed to the tip of the second spindle. The first and second spindles are rotated and moved in directions opposite to each other to simultaneously process the work from both sides of the work when processing the work. An NC control unit for controlling two drive units and each spindle drive unit is provided.

[0007]

In this configuration, the first tool head and the second
The tool heads are opposed to each other with the work interposed therebetween, and furthermore, the two tool heads are substantially concentric because the second spindle for holding the second tool head is arranged to penetrate the inside of the first spindle for holding the first tool head. Since it is disposed on the upper side, it is possible to easily process a processing portion positioned with the narrow portion of the small diameter therebetween with high precision coaxiality.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view showing an embodiment of an NC boring apparatus according to the present invention. In FIG. 1, a jig 2 as a work holding unit that is carried in and out by a transfer device (not shown) is arranged at a substantially central portion on a base 1. A work 3 such as a hub is clamped in the jig 2. The first unit 4 is disposed on the right side of the figure with the jig 3 therebetween, and the second unit 5 is disposed on the left side of the figure.

The first unit 4 includes an AC servomotor 6 for driving the unit, a spindle motor 7 for rotating the first spindle, and an AC motor for driving the second spindle.
The first unit 4 includes a servo motor 8 and the like.
Is configured to be movable by the AC servomotor 6 in the direction of approaching and separating the jig 2 with respect to the base 1 in a ball screw manner. The second unit 5 is provided with a tool head holder 9 as a tool head holder for detachably holding a second tool head 40 described later, and the second unit 5 is hydraulically operated. Base 1
The jig 2 is configured to be movable toward and away from the jig 2. Then, the AC servomotors 6, 8,
The spindle motor 7, the hydraulic mechanism of the second unit 5, and the like are controlled by an NC control unit and a sequencer unit 10 as NC control means, as shown in FIGS.
The driving is controlled as shown in the flowchart shown in FIG.

Next, the detailed structure of the first unit 5 will be described with reference to FIGS. In FIG.
In the housing 21, a drive shaft 22 keyed to the shaft of the spindle motor 7 is supported. A first gear 23 is integrally connected to the outer periphery of the drive shaft 22, and a second gear 24 meshing with the first gear 23 is provided by key fitting to the outer periphery of the first spindle 25.

The first spindle 25 has a hollow, substantially cylindrical shape, is rotatably supported in the housing 21, and has a hollow first tool head (for holding a processing tool) at an end of the jig 2 that holds the work 3. The quill 26 is attached concentrically and freely. The outer shape of the first tool head 26 is formed in accordance with the shape of the work to be processed, and a chip for processing the work 3 is formed on the outer periphery so as to be detachably attachable. On the inner surface of the first spindle 25, metal bearings 27 are provided at two places via a holding member 26 or directly, and between these metal bearings 27, a spline having a substantially cylindrical shape and having spline teeth formed on the inner surface. The member 28 is fixed. Then, the first spindle 25 and the first tool head 26
, A second spindle 29 is provided.

The second spindle 29 has a hollow shape with a diameter smaller than the minimum inner diameter of the work 3, and has spline teeth for spline fitting with the spline member 28 on the inner surface of the first spindle 25. And the first tool head 26 is integrally rotated.
Also, as shown in FIG. 3, the second spindle driving AC
The servo motor 8 has a ball screw composed of a male screw 31 screwed to a nut 30 (see FIG. 2) coupled via a coupling 32. The male screw 31 has a base end and a front end mounted on the housing 21 with bearings 33, 34. Is pivoted through. When the male screw 31 is rotated by the rotation drive of the AC servomotor 8, the nut 30 moves in accordance with the rotation direction.
As shown in FIG. 7, the second spindle 29 moves in the axial direction with respect to the first spindle 25 and the first tool head 26 via a bearing 35 integrated with the nut 30. Accordingly, the second spindle 29 is configured to be integrally rotatable and axially movable relative to the first spindle 25 and the first tool head 26.

A draw bar 36 for clamping the second tool head 40 and fixing it to the tip of the second spindle 29 penetrates through the second spindle 29. The drawbar 36
As shown in FIG. 3, a rod 38 of a rotary fluid pressure cylinder 37 as a drawbar driving means connected to the base end of the second spindle 29 is connected to the base end of the second spindle 29. The rotary fluid pressure cylinder 37 supplies and discharges a working fluid to and from a fluid chamber on both sides of an internal piston through a rotary joint 39 fixed to the housing 21, and moves the draw bar 36 to the second spindle 29 relative to the second spindle 29. Move in the direction.

The details of the second tool head 40 will be described with reference to FIG. In FIG. 4, the second tool head 40 has a substantially cylindrical hollow shape, and a work processing chip (not shown) is detachably attached to the outer periphery of a head body 41 which can be key-fitted to the tip of the second spindle 29. It is supposed to be. The head body 41 has a plurality of balls around it.
And a sleeve 44 slidably provided between the outer periphery of the clamper 43 and the inner periphery of the head body.
And a spring 45 for constantly urging the sleeve 44 elastically toward the distal end of the second spindle (leftward in the figure). In a state before the connection with the second spindle 29, the sleeve 44 has a snap ring due to the elastic force of the spring 45.
It has moved to the position regulated by 46, in this state,
The concave portion 44a on the inner surface of the sleeve 44 is located at the position of the ball 42 of the clamper 43, and the ball 42 is in a state capable of protruding toward the sleeve 44 side. At this time, the leading end of the draw bar 36 enters the clamper 43 due to the approach operation of the second tool head 40 and the second spindle 29. Drawbar 36 tip is clamper 43
When the second tool head 40 and the second spindle 29 further approach each other after entering the inside, the tip of the second spindle 29 abuts against the sleeve 44 and presses the sleeve 44 against the elastic force of the spring 45, and the sleeve 44 Is the position shown in FIG. In this state, the ball 42 projects from the inner surface of the clamper 43 by the inner surface of the sleeve 44. When the draw bar 36 is moved backward (moves leftward in FIG. 4), the tip of the draw bar 36 is engaged with the ball 42, and the second tool head 40 is clamped by the draw bar 36 and integrated with the second spindle 29. Thus, the second spindle 29 and the second tool head 40 can be integrally rotated.

Next, the operation of the NC boring apparatus of this embodiment will be described with reference to the flowcharts and timing charts of FIGS. 5, 6, and 7. First, when the processing cycle starts, the work 3 is carried into the jig 2 by the transfer device, the work 3 is clamped, and a clamp confirmation operation of the work 3 is executed. Also, at the start of the machining cycle, an orientation for positioning the spindle and the tool head for machining the workpiece of the first unit 4 is started simultaneously with the loading of the workpiece by the transfer device.

When the clamping of the work 3 is confirmed, the AC servomotor 6 is driven to advance the first unit 4 to the jig 2 side at a rapid feed to the original processing position (processing start point). When it is confirmed that the first unit 4 has reached the original processing position, the second unit 5 is advanced to the jig 2 by the hydraulic drive at the same rapid traverse. With the forward movement of the second unit 5, the tip of the drawbar 36
The second spindle unit 29 enters the second tool head 40 held by the tool head holding unit 9 of the second unit unit 5, and the tip of the second spindle 29 is connected to the sleeve in the second tool head 40.
The sleeve 44 is pressed against the elastic force of the spring 45 in the right direction in FIG. When the second unit 5 reaches the predetermined forward end, as shown in FIG.
The drawbar 36 is located at the position shown by the dashed line, and the ball 42 of the clamper 43 is regulated by the inner surface of the sleeve 44 so as to protrude inward.

When the second unit 5 reaches a predetermined forward end, this checking operation is executed. Then, when the arrival at the forward end is confirmed, next, the supply and discharge of the working fluid to and from the rotary fluid pressure cylinder 37 are controlled to move the drawbar 36 backward. As a result, the tip of the draw bar 36 engages with the ball 42 at the solid line position in FIG.
It is integrally connected to the tip of the spindle 29. Then, the seating of the second tool head 40 is confirmed, and the tool head holder 9 is checked.
The second tool head 40 is released from the tool head holder 9 by moving in the direction of the arrow in FIG. As a result, two tool heads sandwiching the work 3
26 and 40 are coaxially opposed.

Next, the spindle motor 7 is driven to
And the rotation of the second spindles 25 and 29 starts,
The second unit 5 performs a retreat operation. In the rotation mechanism of the first and second spindles 25 and 29, when the spindle motor 7 rotates, the first gear 23 rotates via the drive shaft 22 key-fitted to the rod. The rotation of the first gear 23 is transmitted to the first spindle 25 via the second gear 24,
The first spindle 25 and the first tool head 26 rotate.
When the first spindle 25 rotates, the spline member
The second spindle 29 rotates via 28 and the fluid rotating cylinder
37 and the drawbar 36 also rotate together, and the second tool head
40 rotates. Therefore, the first and second spindles 25, 2
9. The first and second tool heads 26, 40 start to rotate integrally by the driving of the spindle motor 7.

Then, the first and second tool heads 26, 40
At the same time, the AC servo motor 6 is driven to move the first unit 4 forward, and the first spindle 25 and the first
At the same time as the tool head 26 is advanced, the AC servo motor 8 is driven to move the second spindle 29 through the ball screw including the screw 31 and the nut 30 to the first spindle 25.
Is moved backward to the opposite side of the first unit 4 to move the second tool head 40 forward to the workpiece 3 side.
The cutting of the workpiece 3 is started by the tool head 26 and the second tool head 40. At this time, since the second spindle 29 is provided on the first unit 4, the retreat speed of the second spindle 29 is set faster than the forward speed of the first unit 4.

Next, when it is confirmed that the second spindle 29 has reached the retreat end, it is determined that the work cutting on the second tool head 40 side has been completed, and the AC servo motor 8 is rotated in the reverse direction to rotate the second spindle 29. Is moved forward by fast forward. Then
When it is confirmed that the first unit 4 has reached the advancing end, it is determined that the work cutting on the first tool head 26 side has been completed, and the rotation of the spindle motor 7 is stopped to stop the first and second spindles 25 and 29. And the first and second tool heads 2
Stop the rotation of 6, 40, and
Is rotated in the reverse direction to retract the first unit section 4 by rapid traverse. Then, it is confirmed that the first unit 4 has reached the original processing position and that the second spindle 29 is at the forward end.

Next, the orientation of the spindle and the tool head of the first unit 4 is performed, and the second unit 5 is moved forward to the work side by rapid traverse, and an operation of confirming that it has reached the forward end is performed. Next, the supply and discharge of the working fluid of the fluid rotating cylinder 37 are performed in reverse, the draw bar 36 is advanced, and the clamp of the second tool head 40 is released (unclamped). Then, the tool head holder 9 of the second unit 5 is tightened to hold the second tool head 40 on the second unit 5 side.

When the holding operation of the second tool head 40 by the tool head holder 9 is completed, the first and second unit sections 4, 5 are respectively retracted. Then, after confirming that the retreat end of each of the unit sections 4 and 5 has reached, the clamp of the cut work 3 is released (unclamped), and the work 3 is carried out by the transfer device. According to the NC boring apparatus of the present embodiment, the first unit 4
In addition, since the two tool heads 26 and 40 can be opposed to each other across the work and can be coaxially arranged, even a work 3 having a narrow portion in the middle of processing can be machined with high accuracy of coaxiality. It can be applied very easily. In this embodiment, since both tool heads 26 and 40 can be freely attached and detached, it is possible to cope with multi-kind machining. Further, the second tool head 40 is capable of automatic setup change by ATC (auto tool change).

[0023]

As described above, according to the present invention, 1
Two tool heads are placed on one unit so that they face each other with the work in between, and are arranged coaxially. Both tool heads are moved in opposite directions to enable simultaneous machining from both sides of the work. Even with a workpiece having a narrow portion with a small diameter, it is possible to extremely easily and efficiently perform processing with high coaxiality.

[Brief description of the drawings]

FIG. 1 is a schematic overall view showing an embodiment of an NC boring apparatus according to the present invention.

FIG. 2 is a configuration diagram of a spindle rotation drive unit of the first unit unit of the embodiment.

FIG. 3 is a configuration diagram of a slide drive unit of a second spindle and a drawbar of the first unit unit of the embodiment.

FIG. 4 is an enlarged configuration diagram showing a clamp mechanism of a second tool head according to the embodiment.

FIG. 5 is a flowchart for explaining a machining step of the embodiment.

FIG. 6 is a flowchart for explaining a processing step of the embodiment.

FIG. 7 is a timing chart for explaining a processing step of the embodiment.

[Explanation of symbols]

Reference Signs List 1 base 2 jig 3 work 4 first unit 5 second unit 6 AC servomotor (for driving first unit) 7 spindle motor 8 AC servomotor (for second spindle slide) 9 tool head holder 10 NC control unit and sequencer unit 25 First spindle 26 First tool head 29 Second spindle 36 Drawbar 37 Fluid rotary cylinder 40 Second tool head

Claims (1)

(57) [Claims] A work holding portion provided at a substantially central portion of a base for holding a work to be machined, and opposed to the work holding portion with the work holding portion interposed therebetween, the work holding portion being movable toward and away from the work holding portion; A first and a second unit provided on the base, and first and second unit driving means for slidingly driving the first and the second unit, respectively, wherein the first unit A hollow first spindle rotatably supported by the housing and having a hollow first tool head for holding a machining tool concentrically and removably attached to an end of the workpiece holding portion on the side of the workpiece holding portion; A hollow second spindle that penetrates the first tool head, is integrally rotatable with respect to the first spindle and the first tool head, and is axially movable with respect to the first spindle and the first tool head; A drawbar; drawbar driving means attached to an end of the second spindle opposite to the work holding portion for slidingly driving the drawbar with respect to the second spindle; and a drawbar driving means for moving the second spindle to the first spindle and the first tool. A second spindle driving unit that slides and drives the head; and a first spindle driving unit that rotationally drives the first spindle, wherein the second unit is clamped by the tip of the draw bar, and A tool head holding portion that is disposed opposite to the first tool head and that detachably holds a second tool head for holding a processing tool that can be fixed to the tip end of the second spindle, and that is configured to work. At times, the first and second spindles are rotated and moved in opposite directions to rotate the work from both sides of the work. NC boring apparatus, comprising the NC control means for controlling each drive means and the spindle drive means of said first and second units so as to simultaneously process the click.