JPS6128646Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a shank-type boring bar bite correction device that makes it possible to automatically correct the wear amount of the boring bar bite used in machine tools with automatic tool changers. .

2. Description of the Related Art Conventionally, in boring processing in a machine tool such as a machining center that automatically exchanges tools, an automatic adjustment device for a cutting edge of a cutting tool is known. However, in a conventional automatic adjustment device for the cutting edge of a boring bar using rotation of a ratchet wheel, the ratchet wheel is fixed to a camshaft parallel to the axis of the boring bar, as in, for example, Japanese Utility Model Publication No. 52-9677. A ratchet that operates the ratchet wheel is slidably provided in a direction orthogonal to the spindle axis, and the ratchet is operated by a cylinder on the spindle head, and the amount of displacement of the cam is determined by the rotation of the cam that is integrated with the ratchet wheel. The position of the tool cutting edge was automatically adjusted according to the situation. Therefore, for example, when the main shaft is rotating in the normal direction, it is thought that the ratchet wheel and the main shaft rotate together as a unit due to the locking of the angle positioning pawl, but if the main shaft is rotated in the reverse direction or suddenly stopped, Then, the direction of force applied to the angular positioning pawl of the ratchet wheel is reversed. At this time, the spring force pressing the positioning pawl, the reaction force of the bending tool, the frictional force of the cam, and a force greater than the external forces holding the ratchet wheel act inversely, and the ratchet wheel becomes unable to follow rapid rotational fluctuations of the spindle. That is, the rotation of the ratchet wheel is due to the influence of inertia even when no external force is applied, and the main shaft rotates, but only the ratchet wheel is left behind, and as a result, the main shaft stops.
There was a concern that the ratchet wheel would rotate by a unit amount without any external force, in the same situation as if only the ratchet wheel were rotating.

The purpose of this invention is to eliminate the influence of the inertial force of the ratchet due to sudden stop or reverse force of the main shaft by rotatably supporting the shaft to which the ratchet wheel is fixed perpendicular to the boring bar axis through a bearing. Moreover, because the influence of inertia force is eliminated, the ratchet wheel is supported by a bearing and can be rotated with a weak force, eliminating the drawbacks of the conventional method.

The present invention will be explained below with reference to the drawings.

In FIG. 1, a tapered shank portion 1 of a tool inserted into the main shaft of a machine tool has a gripper groove at its tip for use in tool exchange. At the tip of the tapered shank part, there is a large diameter flange part 19 of the boring bar.
are fixed with bolts 39 and integrated.

The shafts 25A, 25B of the ratchet wheel 18 shown in FIG.
is rotatably provided via bearings 26 and 27. Further, a sliding piece 8 having a pawl 2 that engages with the teeth of the ratchet wheel 18 shown in FIG. Installed so that it can slide freely. The sliding piece 8 is provided with an elongated hole extending in the axial direction and passing through the sliding piece 8 at right angles to the central axis of the sliding piece 8 within a plane including the axis of the main shaft.

A claw 2 is pivotably attached to a pin 3 fixed at right angles to both walls of the elongated hole. The claw 2 is inserted into a hole provided in the shank portion 1 via a spring 24.
By constantly pressing the back surface of the pawl 2 with a press pin 23 loosely fitted into the large diameter flange portion 19, the pawl 2 is engaged with the pawl of the ratchet wheel. A spring 21 is inserted in a compressed state between the shoulder of the stepped portion formed at the other end of the sliding piece 8 and the shoulder of the stepped portion of the through hole 41. 8 is being pushed out to the outside, but the pin 22 fixed to the hole provided in the large diameter flange portion 19 is pushed out of the elongated hole 4 of the sliding piece 8.
It engages with the side wall of No. 2 to prevent it from coming off.

When the boring bar attached to the main shaft is indexed to a predetermined rotation angle position, the cylinder 28 is moved around the main shaft so that the tip of the sliding piece 8 and the piston rod 7 that operates the sliding piece 8 face each other. Fixed to the head wall.

As mentioned above, the sliding piece 8 held by the pin 22 is sealed by an O-ring, and on the opposite side of the abutting portion of the sliding piece 8, a piston sealed with an O-ring is provided. Since it is screwed onto the sliding piece 8, cutting agents and chips from the outside can be removed.
Prevents other dust from entering. This complete seal traps air inside, but since the sliding piece 8 and the piston attached on the opposite side to the sliding piece have the same diameter, air is trapped in accordance with the movement of the sliding piece. The air also moves and has no effect on external forces. Also bowling bar 1
4 is provided with an axial hole 40 eccentrically with respect to the central axis of the boring bar, and a pressing member 15 is slidably provided in the hole. Near the tip of the boring bar 14, a slotted portion 1 is cut from the outer periphery on the side opposite to the bit mounting side, beyond the center axis of the boring bar.
3 is an axial hole 4 into which the pressing member 15 is loosely fitted;
I am in contact with 0. One end of the pressing member 15 is in contact with the wall on the tip side of the slotted portion, and a screw cut at the other end of the pressing member 15 is screwed into the abutting body 16 to prevent loosening and adjust the length. sim 10
It is locked by the nut 11 via the nut 11.

That is, the shim 10 squeezed between the nut 11 and the abutment body 16 has one end of the abutment body 16 in contact with the eccentric cam 17, and the shim 10 is pushed against the wall of the slotted portion 13 due to the spring action. The thickness is adjusted to apply a preload to the pressing member.

Next, a boring bar with an exchangeable tip tool is as shown in FIG. That is, a step 36 was provided on the cut surface 35 so as to diagonally cross the axial hole drilled in the boring bar on the tip side of the boring bar, and the cutting tool 12 was set with a bolt 34 based on the step 36 on the inclined surface. A cassette 33 is detachably attached. The cassette is provided with a slot, and when attached to the inclined surface of the tip of the boring bar, the wall of the slot comes into contact with the axis of the pressing member 15 at right angles.

The shim 38 sandwiched between the pressing member 15 and the bolt 37 is thick enough to apply preload to the pressing member 15 as described above. Therefore, when it is desired to change the boring diameter, by preparing several types of tip cassettes and replacing them, the large diameter flange portion 19 with a correction mechanism can be made versatile. Becomes cheaper.

The present invention is constructed as described above and operates as follows. First, when the boring process is completed, the inner diameter of the workpiece is automatically measured using a known measuring means. This measured value is stored in a storage device, the measured value and the set value are compared, and if it is within the tolerance range, boring is performed again without adjusting the bite 12 of the boring bar 14 during the next processing. If the tolerance range is exceeded, a predetermined signal for tool correction is generated when the boring bar is used for the next machining. In response to this signal, a solenoid valve (not shown) is switched, and the piston 5 is moved forward by the fluid pressure flowing in from the inlet 31 of the cylinder 28 shown in FIG.

As mentioned above, the sliding piece 8 and the piston rod 7
are indexed by the main shaft to positions opposite to each other, so that the piston rod 7 and the sliding piece 8 that have moved forward come into contact with each other. Furthermore, when the sliding piece 8 is pushed forward by the piston rod 7, the sliding piece 8
The claw 2, which is loosely fitted in a swingable manner, moves forward through the pin 3. Therefore, the ratchet wheel 18 engaged with the pawl 2 rotates clockwise by one blade, and the eccentric cam 17, which is provided integrally with the ratchet wheel, similarly rotates. Due to the rotation of the eccentric cam, the pressing member 15 moves slightly forward in the direction of the tip of the boring bar via the contact body 16 by the amount of displacement of the eccentric cam. The slotted portion is expanded by the pressing force of the pressing member that is in contact with one side wall of the slotted portion provided at the tip of the boring bar, and the cutting tool provided at the tip of the boring bar is moved in the outer radial direction. Then, when the piston rod 7 retreats, the cylinder 2
A dog 32 protruding from the rear of the sensor 8 depresses the limit switch 4, and one unit of correction determined by a certain correction value is completed.

If one unit of correction does not complete the correction, this series of steps may be repeated a predetermined number of times.

According to this invention, the inner diameter is automatically measured when the boring process is completed, the measured values are compared, and if it is out of the tolerance range, the position of the cutting tool is automatically adjusted by a predetermined correction amount. can be corrected accordingly. Therefore, it becomes possible to perform hole boring with high precision and high efficiency in a machine tool that automatically changes tools, such as a machining center.

As described above, the present invention is not limited to the configurations shown in the embodiments, and modifications are expected within the scope of the technical idea of the present invention as described in the claims.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the relationship between the boring bar of the present invention and a cylinder operated by fluid pressure. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a sectional view taken along the line BB in FIG. Fourth
The figure is a sectional view of the boring bar for large diameter machining of the present invention. In the figure, 1...Shank, 2...Claw, 3...
...Pin, 4...Limit switch, 8...Sliding piece, 10...Shim, 12...Bite, 13...Slit portion, 14...Boring bar, 15...Press member, 16...Abutting body , 17... Eccentric cam, 1
8... Ratchet wheel, 19... Large diameter flange portion, 20... Piston, 21... Spring, 22...
...Pin, 23...Press pin, 24...Spring, 25
A, 25B... shaft, 26, 27... bearing, 28...
... cylinder, 32 ... dog, 33 ... cassette, 36 ... stepped section, 38 ... shim, 42 ... oblong hole.

Claims (1)

[Scope of utility model registration request] It has a spindle that is rotatably installed on the spindle head of a machine tool, and a shank that is detachably inserted into the spindle, and the tip can be elastically deformed to be displaced in the radial direction of the bore hole of the workpiece. a tool body having a cutting edge position adjustment mechanism, and a ratchet wheel rotatably supported within the tool body in a plane parallel to a plane including the main shaft axis and having an eccentric cam in the rotation direction. , a sliding piece slidably provided in a through hole perpendicular to the spindle axis in the tool body, and a sliding piece provided swingably on the sliding piece and constantly engaged with teeth of the ratchet wheel; a pawl that rotates the ratchet wheel by a unit amount by movement of the movable piece; and a pawl arranged to face the sliding piece and come into contact with the sliding piece when the main shaft is indexed to a constant angle position. a pressing member inserted into the tool body with its tip abutting the cutting edge position adjustment mechanism and its rear end abutting the eccentric cam; and a sliding force generated by the direct acting drive source. The blade edge position adjustment mechanism is relatively elastically deformed by the displacement amount due to the rotation of the eccentric cam through the ratchet wheel by the operation of the moving piece, and the blade edge is moved in the radial direction to correct the amount of wear on the blade edge. A boring bar equipped with a tool compensation device.