JPH0323284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a boring device for cutting a hole in a workpiece.

<Prior Art> A boring device in which a cutting tool can be automatically switched to a plurality of protrusion amounts corresponding to different hole diameters to be machined is known from Japanese Utility Model Application No. 55-75403.

However, in this conventional device, in order to accommodate various hole diameters, the cam member must be lengthened to form a multi-stage cam surface, which makes the quill long and prone to vibrations. The positioning mechanism also becomes complicated. Therefore, in reality, only two types of hole diameters could be accommodated.

<Object of the Invention> The present invention enables a cutting tool to be adapted to any hole diameter without increasing the length of the boring quill, and allows highly accurate wear correction.

<Structure of the Invention> The present invention has a main shaft rotatably supported on a shaft head body, an eccentric shaft rotatably supported within the main shaft at a position eccentric to the main shaft axis, and a tip of the eccentric shaft. fix the boring quill concentrically with the eccentric shaft,
A cutting tool is attached to this boring quill so that it can move back and forth in the radial direction, and a movable cylinder that is threadedly engaged with a lead screw provided at the rear end of the eccentric shaft is supported within the main shaft so that it can move only in the axial direction of the main shaft. A rotation indexing mechanism is provided for rotationally indexing the eccentric shaft in order to move the cylinder in the axial direction according to the machining diameter of the workpiece so that the rotation radius from the main axis axis of the cutting tool corresponds to the machining diameter of the workpiece, A clamper is provided that engages with an engagement surface provided on the outer circumferential surface of the eccentric shaft to integrally connect the eccentric shaft in the rotational direction of the main shaft, and an unclamping device is provided that releases the clamper from the engagement surface. A forward/backward shaft is passed through the quill and the eccentric shaft so as to be movable only in the axial direction concentrically with the eccentric shaft, a cam is provided at the tip of the forward/backward shaft, and the cam and the cutting tool are connected via an operating pin, A connecting shaft is connected to the rear end of the main shaft concentrically with the main shaft so as to be relatively movable only in the axial direction,
The forward and backward shaft is rotatably supported at the tip of the connecting shaft at an eccentric position, and the forward and backward shaft is moved in the axial direction via the connecting shaft according to the amount of wear correction of the cutting tool at the rear end of the connecting shaft. This is a boring device equipped with a cutting tool extension mechanism.

<Examples> Examples of the present invention will be described below based on the drawings.
In FIG. 1, reference numeral 1 denotes a slide table that moves in parallel to the axis of the main shaft on a base (not shown). A spindle head 2 is fixed on this slide table 1,
A main shaft 3 is rotatably supported on the main shaft head 2 by a bearing. A pulley 4 is fixed to the rear end of the main shaft 3, and a belt is hung between the pulley 4 and a motor (not shown).

An eccentric shaft 5 is supported within the main shaft 3 at an axis 02 that is eccentric with respect to the main shaft axial center line 01 so as to be capable of independent index rotation and rotation integrally with the main shaft 3. A boring quill 6 is attached to the tip of the eccentric shaft 5 so as to be concentric with the axis 02 of the eccentric shaft 5. Boring quill 6
A cutting tool 7 that can move forward and backward in a direction orthogonal to the axis 02 of the eccentric shaft 5 is attached to the. 8 is a flexible portion that allows the cutting tool 7 to move forward and backward.

The independent index rotation mechanism of the eccentric shaft 5 is as follows. A lead screw 9 as a motion conversion mechanism is provided on the outer periphery of the rear end of the eccentric shaft 5, and a movable cylinder 10 is screwed onto the lead screw 9. This movable cylinder 10 can be slid relative to the main shaft 3 in the axial direction, and is engaged with the main shaft 3 by a key member 11 so as to rotate integrally with the main shaft 3 in the rotational direction.
The rear end of the movable tube 10 projects outward from the rear end surface of the main shaft 3, and a connecting body 12 is attached to the protruding rear end of the movable tube 10 to allow rotation of the movable tube 10 and restrict movement in the axial direction. are combined. This connected body 1
2 is screwed through a nut 16 to a feed screw 15 that protrudes from a gear box 14 fixed to the spindle head 2 via a bracket or the like on an axis parallel to the main shaft 3, and the feed screw 15 is attached to the gear box. The forward and reverse rotation of the servo motor 13 fixed to the gear box 14 causes the gear mechanism in the gear box 14 to decelerate and rotate the connecting body 12, moving the connecting body 12 forward and backward, transmitting the forward and backward movement of the connecting body 12 to the movable cylinder 10, The eccentric shaft 5 is indexed and rotated about its eccentric axis 02 via the lead screw 9 by the forward and backward movement of the shaft 10.

Furthermore, the mechanism for rotating the eccentric shaft 5 integrally with the main shaft 3 is as follows. A clamp rod 17 parallel to the axis of the main shaft 3 is provided so as to be movable forward and backward in the axial direction.
will be established. The clamp rod 17 is provided with a clamp spring 20 that always pushes the clamp rod 17 in the forward direction, and the forward movement of the clamp rod 17 causes the clamper 18 to engage the engagement surface 19 provided on the outer periphery of the tip of the eccentric shaft 5. The main shaft 3 and the eccentric shaft 5 are engaged with each other to integrally connect the main shaft 3 and the eccentric shaft 5 in the rotational direction. Since it is necessary to disengage the clamper 18 from the engagement surface 19 during independent index rotation of the eccentric shaft 5,
As an unclamping mechanism, a movable block 21 is provided at the rear end of the clamp rod 17, and a movable block 21 is provided at the rear end of the clamp rod 17.
A moving ring 22 is provided on the top to be slidable in the axial direction and rotatable relative to the main shaft 3. Then, the movable block 21 and the movable ring 22 are connected by a connecting pin 23. Furthermore, an unclamping cylinder 24 is installed on the spindle head 2, and an engagement block 25 is provided at the end of the piston rod. Between the engagement block 25 and the movable ring 22, a pivot lever 26 that can be pivoted in the front and rear direction is pivoted to the spindle head 2 by a pivot pin 27, and one end of the pivot lever 26 is connected to the engagement block 22. The other end is connected to the moving ring 2 through an engaging roller 51 as shown in FIG.
2, and the clamp rod 17 is moved backward against the forward pushing force of the clamping spring 20 to unclamp it.

Next, a mechanism for advancing and retracting the cutting tool 7 at the tip of the boring quill 6 will be explained with reference to FIGS. 1 and 2. This movement of the cutting tool 7 back and forth is mainly a protrusion for correcting wear of the cutting tool 7. As mentioned above,
The cutting tool 7 is attached to the tip of the boring quill 6 by a flexible portion 8 so as to be movable forward and backward. Therefore, a protruding rod 29 is provided within the axis of the boring quill 6 so as to be able to slide forward and backward in the axial direction. A cam surface 30 is formed at the tip of this protruding rod, and a movable pin 31 is interposed between this cam surface 30 and the back surface of the cutting tool 7. The cutter 7 is extended through the cutter 31. The rear end of the protruding rod 29 is connected to the tip of a reciprocating shaft 28 that runs vertically through the axis of the eccentric shaft 5. Further, the rear end of the advance/retreat shaft 28 is connected to the main shaft 3
It is joined to the tip of the connecting shaft 32 which is concentric with the connecting shaft 32 . As mentioned above, this connecting shaft 32 is concentric with the main shaft 3,
It must rotate integrally with the main shaft 3, allow forward and backward movement in the axial direction, and be connected to the forward and backward shaft 28 which is concentric with the axis 02 of the eccentric shaft 5. Therefore, the joint 33 engages the main shaft 3 in the rotational direction and allows movement in the axial direction. And this joint 3
3, the rear end of the advance/retreat shaft 28 is coupled to allow relative rotation and to restrict movement in the axial direction.

A correction device for moving the connecting shaft 32 forward and backward to extend the cutting tool 7 is shown in FIG. That is, a cylinder 35 concentric with the connecting shaft 32 is provided on a support base 34 fixed on the same slide table 1 on which the spindle head 2 is fixed, and a piston 36 can be moved forward and backward within this cylinder 35. Insert. Piston rods 37a and 37b are provided on both left and right sides of the piston 36 and project outward from both left and right side walls of the cylinder 35. A connecting block 39 is provided at the tip of one of the piston rods 37a, 37b, and the connecting shaft 32 is connected to the connecting block 39.
The rear end allows rotation and restricts movement in the axial direction. Further, an intermediate block 38 is provided on the piston rod 37a, and this intermediate block 38
A detent shaft 42 that is perpendicular to the axis of the piston rod 37a is protruded from the piston rod 37a and comes into contact with a guide surface 41 of a bracket 40 fixed to the support base 34.

Furthermore, a stopper cylindrical shaft 43 is fitted onto the other piston rod 37b so as to be slidable in the axial direction, and the tip of the stopper cylindrical shaft 43 is connected to the cylinder 37b.
It protrudes so that it can appear inside. A screw 52 and a spline 49 are provided on the stopper cylinder shaft 43, the screw 52 is screwed into a fixing nut 44 fixed to the support base 34, and the spline 49 has a large diameter rotatably supported on the support base 34. It is spline fitted to the gear 48. Further, a pulse motor 45 for protruding the cutter is fixed on the support base 34, and the large diameter gear 48 is mounted on the rotation shaft 46 of this pulse motor 45.
A small-diameter gear 47 that meshes with is provided. 50
1 is a rotation amount detection device of the pulse motor 45, which is composed of, for example, a toothed wheel and a proximity switch.

Since the present invention has the above-described structure, when cutting the hole diameter of a workpiece, the clamp rod 17 is moved forward by the clamp spring 20, and the clamper 18 is engaged with the engagement surface 19 of the eccentric shaft 5. , the main shaft 3 and the eccentric shaft 5 rotate in the same direction. Therefore, the rotational force transmitted to the pulley 4 causes the main shaft 3 to
and the eccentric shaft 5 rotate together. Further, the movable cylinder 10 screwed into the lead screw 9 of the eccentric shaft 5 also rotates together with the main shaft 3 and the eccentric shaft 5. Further, the connecting shaft 32, which engages the movable cylinder 10 only in the rotational direction, also rotates integrally with the main shaft 3.

The eccentric shaft 5, which rotates integrally with the main shaft 3, rotates around the axis 01 of the main shaft 3. Therefore, the turning trajectory of the cutting edge of the cutting tool 7 at the tip of the boring quill 6 is a radius circle centered on the axis 01 of the main shaft 3, and the length of this radius is determined by rotating the eccentric shaft 5 to an arbitrary position with respect to the main shaft 3. The changes can be made by issuing new information.

Rotation indexing of the eccentric shaft 5 by changing the diameter of the machined hole is performed by the following operation. First, the unclamping cylinder 24 is activated, and the rotating lever 26 is rotated clockwise in FIG.
Shift 2 to the left. This moving sleeve 22
As a result of the leftward shift, the clamp rod 17 also compresses the clamping spring 20 and is shifted to the left, disengaging the clamper 18 from the engagement surface 19 and moving the clamp rod 17 toward the main shaft 3.
The rotational direction engagement between the eccentric shaft 5 and the eccentric shaft 5 is released, and the eccentric shaft 5 is allowed to rotate independently.

Next, the servo motor 13, which has received the required index signal, rotates either forward or reverse to rotate the feed screw 15. Based on the rotation of this feed screw 15, the connecting body 1
2 moves forward and backward to move the movable cylinder 10 forward and backward.
As the movable cylinder 10 moves forward and backward, the eccentric shaft 5 is rotated forward and backward by the lead screw 9, and the turning radius length of the cutting edge of the cutting tool 7 about the axis 01 of the main shaft 3 is divided so as to correspond to the hole diameter to be machined. It is put out.

Next, the operation for correcting the wear of the cutting tool 7 is as follows. That is, the pulse motor 45 operates based on the correction command, causing the small gear 47 to rotate the large gear 48 . The rotation of this large gear 48 is caused by splines 49
The transmission is transmitted to the stopper cylinder shaft 43 by the screw 52 screwed into the fixing nut 44.
3 is moved slightly to the left in FIG. 2, and the position of the tip protruding into the cylinder 35 is slightly retracted to define the retracting end (leftward advancing end in the figure) of the piston 36. Therefore, the piston 36 is at the forward end and the cutter 7 is at the retracted position where it is most released, but by moving the piston 36 to the retracting end defined by the stopper cylinder shaft 43, the piston rod 37a, the connecting shaft 32, and the forward and backward movement A rod 29 protrudes through the shaft 28
The movable pin 3 is moved backward by the cam surface 30.
1, the cutting tool 7 is protruded by the required correction amount.

In addition to the correction protrusion due to the wear of the cutting tool 7, when the boring quill 6 is pulled out from the hole after cutting the hole, the piston 36 is moved to the forward end to move the cutting tool 7 backward and escape. It is also used to prevent scratches on the machined surface by preventing it from hitting the machined surface.

<Effects> As described above, according to the present invention, by rotationally indexing the eccentric shaft using the rotary indexing mechanism, the cutting tool at the tip of the boring quill performs cutting from the spindle center according to the machining diameter of the workpiece. The radius is set steplessly, allowing it to accommodate a variety of hole diameters without increasing the length of the quill.

In addition, by moving the connecting shaft and the advancing/retracting shaft integrally with each other using the cutting tool extension mechanism,
The set wear amount of the cutting tool can be corrected, and highly accurate cutting of the set hole machining size can always be obtained.

Furthermore, the rotation indexing, cutting tool extension, and coupling mechanism for integrally integrating and releasing the eccentric shaft and the main shaft are all operated fully automatically by actuator operation based on command signals, eliminating the labor and adjustment errors caused by manual adjustment by the operator. It will be resolved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the shaft head of the present invention, FIG. 2 is a sectional view of the cutting tool correction actuating device, and FIG. 3 is a sectional view of the shaft head of the present invention.
FIG. 1...Slide table, 2...Spindle cylinder, 3...
... Main shaft, 5 ... Eccentric shaft, 6 ... Boring quill, 7
...cutting tool, 9...lead screw, 10...movable tube,
12... Connecting body, 13... Servo motor, 15...
...Feed screw, 17... Clamp rod, 18...
Clamper, 19... Engaging surface, 20... Spring for clamping, 24... Cylinder for unclamping,
28...Advance/retreat axis, 29...Protruding rod, 30...
Cam surface, 32... Connection shaft, 34... Support stand, 35
...Cylinder, 36...Piston, 37a, 37
b... Piston rod, 43... Stopper cylinder shaft,
44...Fixing nut, 45...Pulse motor, 4
7... Small gear, 48... Large gear, 49... Spline, 50... Rotation amount detection device, 52... Screw.

Claims (1)

[Claims] 1. A main shaft is rotatably supported on the shaft head body, an eccentric shaft is supported within this main shaft at a position eccentric to the main shaft axis so as to be indexable and rotatable, and a boring quill is attached to the tip of this eccentric shaft as an eccentric shaft. The boring quill is fixed concentrically, and a cutting tool is attached to this boring quill so that it can move forward and backward in the radial direction, and a movable cylinder that is screwed into the lead screw provided at the rear end of the eccentric shaft inside the main shaft can be moved only in the direction of the main shaft axis. rotation for rotating and indexing the eccentric shaft in order to move the movable cylinder in the axial direction according to the machining diameter of the workpiece and to make the rotation radius from the main shaft axis of the cutting tool correspond to the machining diameter of the workpiece. An unclamping device that includes an indexing mechanism, a clamper that engages with an engagement surface provided on the outer peripheral surface of the eccentric shaft to integrally connect the eccentric shaft in the rotational direction of the main shaft, and that releases the clamper from the engagement surface. A forward and backward shaft passes through the boring quill and the eccentric shaft so as to be movable only in the axial direction concentrically with the eccentric shaft, a cam is provided at the tip of the forward and backward shaft, and the cam and the cutting tool are connected to each other by an operating pin. A connecting shaft is connected to the rear end of the main shaft concentrically with the main shaft so that it can move relative to the main shaft only in the axial direction, and a shaft bearing is provided at the tip of the connecting shaft that allows the forward and backward movement shaft to rotate only at an eccentric position. The boring device further comprises a cutting tool extension mechanism provided at the rear end of the connecting shaft to move the advancing/retracting shaft in the axial direction via the connecting shaft in accordance with the wear correction amount of the cutting tool.