JPH0135767Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a boring unit for a machining center with an automatic tool changer, in particular, a screw extending in the radial direction of the unit body at the end opposite to the spindle attachment part of the unit body. This invention relates to a boring unit equipped with a tool holder that allows the unit body to be slightly moved in the radial direction by slow rotation of the shaft.

BACKGROUND ART This type of boring unit uses the slight movement of the unit body of the tool holder in the radial direction caused by the low-speed rotation of the screw shaft to slightly move the cutting tool attached to the boring bar held in the tool holder in the same direction. The purpose of this is to accurately compensate for dimensional fluctuations in the diameter of the bored hole due to wear of the cutting tool. Conventionally, this boring unit requires a high rotational speed of the unit body by the spindle and a low rotational speed of the screw shaft. Due to the fact that the ratio to the speed, that is, the reduction ratio is quite large, a relatively complex structure is required for the reduction mechanism that forms the screw shaft rotation drive device and the disconnection mechanism for this screw shaft rotation drive device, so it is compact. It is said that it is difficult to reduce the weight.

Problems that the invention aims to solve In view of the above points, the main purpose of this invention is to simplify the structure of the deceleration mechanism and intermittent mechanism of this type of boring unit to make it more compact and lightweight. The purpose is

Means for Solving the Problems According to this invention, the above object is achieved by fixing the spindle mounting portion 1 of the unit body 10 as illustrated in the drawings.
A tool holder 16 is provided at the end opposite to the tool holder 16, which can be slightly moved in the radial direction of the unit body 10 by low-speed rotation of a screw shaft 14 extending in the radial direction of the unit body 10.
In a boring unit equipped with
The outer periphery of the unit body 10 is located between the part adjacent to the spindle mounting part 12 of 0 and the screw shaft 14 setting part.
In the state where the unit body 10 protrudes outward, the unit body 10
first and second axially extending grooves 2 adjacent to each other at a distance around the axis on the outer periphery, which are installed concentrically with the unit body 10 and rotatable integrally with the unit body 10 when unrestrained;
2a and 22b, a sun gear 24 installed concentrically with the unit body 10 inside the internal gear 22, and the internal gear 22 and the sun gear 2.
A first gear reduction mechanism 20 including a planetary gear 26 interposed between An elliptical cam 32, an elliptical flexible tooth ring 38 fitted around the cam 32 via an elliptical ball bearing 34 having a flexible outer ring 36, and a flexible tooth ring 38 fitted around the flexible tooth ring 38. a first internally toothed ring capable of forming an input or output or intermediate member having the same number of teeth as the flexible toothed ring 38 and spaced axially so as to engage the long axis of the ring 38; 40 and flexible tooth ring 3
a second inner toothed ring 42 capable of forming an output or intermediate member with more than eight (for example several) teeth;
a second gear reduction mechanism 30 including a second gear reduction mechanism 30, and a pair of bevel gears that transmission connects the first tooth ring 40 or the second tooth ring 42 forming the output member of the second gear reduction mechanism 30 and the screw shaft 14. 44 and 46, while the internal gear 22 of the first gear reduction mechanism 20
Around the 10 parts of the unit body adjacent to the outer periphery of
Outer ring 5 with pressurized fluid path 50a rotatable relative to unit body 10 and internal gear 22
A first gear stopper 54 that can be fitted into the outer ring 50 and engaged with the first axially extending groove 22a of the internal gear 22 to restrain rotation of the internal gear 22.
and the first gear stopper 5 at all times.
4 is engaged with a spring 56 that urges it to engage with the first axially extending groove 22a of the internal gear 22.
A ring restraining pin 52 with a pressurized fluid passage 58 movable in the axial direction of the unit body 10 is attached to the unit body 10.
When the spindle mounting portion 12 is mounted on the spindle 70, the tip engages with the stationary fluid supply block 72 with the pressurized fluid path 74 adjacent to the spindle 70 to restrain the rotation of the outer ring 50, and the spring 56 The first gear stopper 54 is placed in a position separated from the first axially extending groove 22a of the internal gear 22 by moving against the urging force of the ring restraining pin 52. Adjacent thereto, there is a second gear stopper 62 that can engage with the second axially extending groove 22b of the internal gear 22, and the second gear stopper 62 is normally engaged with the second axially extending groove 22b of the internal gear 22. A gear restraining piston 6 movable in the axial direction of the unit body 10 is engaged with a spring 64 that urges it to assume a position where it does not engage with the axially extending groove 22b.
0 from the pressurized fluid path 74 of the stationary fluid supply block 72 to the ring restraint pin 52 and the pressurized fluid path 58 of the outer ring 50 when the spindle mounting portion 12 of the unit body 10 is mounted on the spindle 70.
When fluid pressure is applied through 50a, the spring 6
This is achieved by moving against the biasing force of 4 and positioning the second gear stopper 62 in a position where it engages with the second axially extending groove 22b.

Function: The boring unit according to this invention is installed in the ring restraining pin 52 before the spindle mounting part 12 of the unit body 10 is mounted on the spindle 70, as in the case where it is housed in a magazine of a machining center. The first gear stopper 54 engages with the first axially extending groove 22a of the internal gear 22, while the second gear stopper 62 attached to the gear restraint piston 60 engages with the second shaft of the internal gear 22. When the ring restraining pin 52 is attached to the spindle 70, the tip of the ring restraining pin 52 is immovably engaged with the immovable fluid supply block 72 adjacent to the spindle 70. The ring restraint pin 52 retreats against the biasing force of the spring 56, and the first gear stopper 54 disengages from the first axially extending groove 22a of the internal gear 22. As a result, the outer ring 50 Although it is separated from the gear 22, its rotation is restrained due to its engagement with the immovable fluid supply block 72, resulting in an immovable state.

Therefore, when the unit body 10 is rotated around its axis through the high speed rotation of the spindle 70 in this state, the boring bar 18 with the cutting tool 18a held in the tool holder 16 rotates at high speed integrally with this unit body 10. Therefore, a predetermined boring process is performed.

On the other hand, in this spindle installation state,
The gear restraint piston 60 is connected to the gear restraint piston 60 from the pressurized fluid passage 74 of the stationary fluid supply block 72 via the ring restraint pin 52 and the pressurized fluid passages 58, 50a of the outer ring 50.
When fluid pressure is applied to the gear restraint piston 6
The second gear stopper 62 engages with the second axially extending groove 22b of the internal gear 22 through movement against the biasing force of the spring 64 of become a state.

Therefore, when the unit body 10 is rotated at high speed via the spindle 70 in this state, the sun gear 24 rotates through the rotation along the internal teeth of the internal gear 22 of the planetary gear 26. 1 gear reduction mechanism 20 operates, and along with this,
In general, when the elliptical cam 32 is the input member, the first internal tooth ring 40 is the intermediate member and the second tooth ring 42 is the output member, or the second internal tooth ring 42 is the intermediate member and the second tooth ring 42 is the output member. The first internal toothed ring 40 serves as an output member, and when the first internal toothed ring 40 serves as an input member, the elliptical cam 32 is an intermediate member and the second internal toothed ring 40 serves as an output member.
The internal toothed ring 42 serves as an output member, and the output member rotates by an angle corresponding to the difference in the number of teeth between the second internal toothed ring 42 and the flexible toothed ring 38 for one rotation of the input member. The second gear reduction mechanism 30 operates in this manner, thereby reducing the speed of the pair of bevel gears 4.
Since the screw shaft 14 rotates at a low speed via the screw shafts 4 and 46, the tool holder 16 and the boring bar 18 with the cutting tool 18a move slightly in the radial direction of the unit body 10, and the position of the cutting tool 18a is corrected.

After that, when the action of the fluid pressure is released, the gear restraining piston 60 moves under the biasing force of the spring 64, thereby causing the second gear stopper 62 to move in the second axial direction of the internal gear 22. Since it is separated from the groove 22b, the tool 18a whose position has been corrected is in a state in which it is possible to perform desired and appropriate boring.

Effects of the invention The boring unit according to this invention has a first gear reduction mechanism 20 which is a planetary gear mechanism in which the reduction mechanisms forming the so-called driving device for the screw shaft 14 all have a short shaft length and a relatively small diameter. and a second gear reduction mechanism 30, which can also be called a quasi-gear reduction mechanism, and an intermittent mechanism for the drive device of the screw shaft 14 is connected to a ring restraint pin 5 installed on the outer ring 50.
Since it is composed of two pin-shaped or piston members, ie, the gear restraining piston 60 and the gear restraining piston 60, it can be made more compact and lightweight.

Embodiment The first gear reduction mechanism 20 in the boring unit of this invention can generally be constituted by a single planetary gear mechanism as shown in the drawing. In order to rotate integrally with the unit body 10 when the internal gear 22 is not restrained, the internal gear 22 in the first gear reduction mechanism 20 normally has a spring 28a attached to its side via a ball 28b as shown in the figure. The first and second axially extending grooves 22a and 22b provided in the internal gear 22
In addition to having a partially open shape as shown in the figure, the hole can also be completely surrounded.

Since the second gear reduction mechanism 30 has a large reduction ratio, generally an elliptical cam 32 is fixed to a rotatable sun gear 24 as an input member as shown in the figure.
The outer elliptical cam can be configured such that the first internal ring 40 is immovable and serves as an intermediate member, and the second internal ring 42 is fixed to the bevel gear 44 and serves as an output member. 32 as an input member, the second internal toothed ring 42 as an intermediate member, and the first internal toothed ring 40 as an output member, or
The internal toothed ring 40 of the elliptical cam 3 is used as an input member.
2 as an intermediate member, and the second internal tooth ring 42 as an output member. The difference in the number of teeth between the second internal tooth ring 42 and the flexible tooth ring 38 in the second gear reduction mechanism 30 can be, for example, two.

The outer ring 50 is fitted around the unit body 10 with a ring metal 48 interposed therebetween in order to facilitate relative rotation.

Gear restraint piston 60 installed in outer ring 50
Generally, compressed air or pressurized oil can be used as the pressurized fluid that acts on the air.

In the illustrated example, the tool holder 16 is engaged with the screw shaft 14 via a nut member 16a fixed thereto, and is also slidable in the radial direction of the unit body 10 and engaged in the form of a joint. (details not shown).

[Brief explanation of the drawing]

The drawings show one embodiment of the boring unit according to this invention. Fig. 1 is a partially cutaway front view, Fig. 2 is a partially cutaway right side view, and Fig. 3 is a partially cutaway front view. FIG. 4 is a partial sectional view taken along the line - in FIG. 2, and FIG. 4 is a partial sectional view taken along the line - in FIG. 10...Unit body, 12...Spindle attachment part, 14...Screw shaft, 16...Tool holder, 2
0...first gear reduction mechanism, 22...internal gear,
22a, 22b...Axially extending groove, 24...Sun gear, 26...Planetary gear, 30...Second gear reduction mechanism, 32...Elliptical cam, 34...Ball bearing,
36...Flexible outer ring, 38...Flexible tooth ring, 40
...First internal ring, 42... Second internal ring, 44, 46... Bevel gear, 50... Outer ring,
50a, 58, 74... Pressurized fluid path, 52... Ring restraining pin, 54... First gear stopper, 5
6, 64...Spring, 60...Gear restraint piston,
62... Second gear stopper, 70... Spindle, 72... Stationary fluid supply block.

Claims (1)

[Scope of utility model registration request] A boring unit comprising, at an end of the unit body opposite to the spindle attachment part, a tool holder that can be slightly moved in the radial direction of the unit body by low-speed rotation of a screw shaft extending in the radial direction of the unit body,
Between the part of the unit body adjacent to the spindle installation part and the screw shaft installation part, in a state where the outer peripheral part protrudes outward from the unit body, it is concentrically with the unit body and integrally with the unit body when not restrained. an internal gear rotatably installed and having first and second axially extending grooves adjacent to each other at an interval around the axis on the outer periphery, the internal gear being installed concentrically with the unit body inside the internal gear; a first gear reduction mechanism including a sun gear and a planetary gear interposed between the internal gear and the sun gear; and an input or intermediate gear reduction mechanism installed concentrically with the unit body adjacent to the first gear reduction mechanism. an elliptical cam capable of forming a member; an elliptical flexible toothed ring fitted around the cam via an elliptical ball bearing having a flexible outer ring; and a flexible toothed ring fitted around the flexible toothed ring. a first internally toothed ring capable of forming an input or output or an intermediate member having the same number of teeth as the flexible toothed ring, axially spaced to engage the longitudinal axis of the flexible toothed ring; a second gear reduction mechanism including a second internal gear ring capable of forming an output or intermediate member having more teeth than the tooth ring; and first or second teeth forming the output member of the second gear reduction mechanism. A pair of bevel gears that transmitably connect the ring and the screw shaft are installed, while a pair of bevel gears are installed around the unit body adjacent to the outer periphery of the internal gear of the first gear reduction mechanism. An outer ring with a pressurized fluid path that is relatively rotatable is fitted to the outer ring, and the outer ring can engage with a first axially extending groove of the internal gear to restrain rotation of the internal gear. an axially movable unit body having a first gear stopper and engaged with a spring that normally urges the first gear stopper to engage with the first axially extending groove; When a ring restraining pin with a pressurized fluid path is attached to the spindle mounting portion of the unit body on the spindle, the tip engages with the immovable fluid supply block with a pressurized fluid path adjacent to the spindle and prevents the rotation of the outer ring. and moves against the biasing force of the spring to take a position where the first gear stopper is separated from the first axially extending groove, and is adjacent to the ring restraining pin. The internal gear has a second gear stopper that can engage with the second axially extending groove of the internal gear, and is normally positioned at a position where the second gear stopper does not engage with the second axially extending groove. A gear restraint pin that is movable in the axial direction of the unit body and is engaged with a spring that urges the unit body to move is removed from the pressurized fluid path of the stationary fluid supply block when the spindle attachment part of the unit body is attached to the spindle. When fluid pressure is applied through the ring restraint pin and the pressurized fluid path of the outer ring, the second gear stopper moves against the biasing force of the spring and engages with the second axially extending groove. A boring unit that is installed so that it can be positioned.