JPS6368308A - Drill device - Google Patents

Abstract

PURPOSE:To control the length of cut chips to a predetermined value before they are discharged, by securing a pair of thrust rings to a drill spindle and a casing, respectively, with a predetermined gas therebetween, and by providing a rolling element support ring between the thrust rings so that the rolling element support ring may be relatively rotated following up the rolling of rotating elements. CONSTITUTION:Rolling elements 16 stored in a rolling element support ring 20 which is rotated at a speed equal to theoretically one-half of that of a drill spindle 10, are fitted simultaneously into recesses 27, respectively, for every predetermined rotation of the spindle 10. Then, the drill spindle 10 exerting an advancing force in the thrust direction to a drilling tool 9 is displaced slightly in accordance with the depth of the recesses 27. With this arrangement, the cutting by the drilling tool 9 is instantly ceased, and therefore, chips are cut into a predetermined length for every predetermined rotation of the drill spindle 10 and are discharged from the drilled hole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a drilling device with improved chip discharge performance using a drilling tool.

[Prior art]

A drilling tool such as an annular cutter or a twist drill that has a cutting edge at its tip has a groove connected to the cutting edge on its outer periphery, and chips generated during the drilling operation are discharged out of the hole along the groove. The chips discharged out of the hole in this manner vary depending on the material to be drilled, the cutting speed, the feeding speed of the drilling blade, etc., but usually they are continuously discharged over a predetermined length.

By the way, when thrust is applied to the drilling tool while keeping the feed speed of the drill spindle almost constant, the length of the chips that are continuously ejected out of the hole becomes relatively long, and the cutting speed increases due to the increase in their own weight and ejection resistance. Chip discharge performance deteriorates, chips get stuck between the hole and the drilling tool, and the resulting increased cutting resistance impairs free-cutting performance, reducing drilling efficiency, and even causes the cutting blade to become abnormal. There was a problem that the cutting edge would become dull due to frictional heat. As a simple countermeasure in this regard, conventionally, a barrier member is fixed to the casing located above the drilling tool so that it can come into contact with a continuous series of chips, and the chips come into contact with the barrier member. Techniques have been proposed in which chips are forcibly broken off by impact or resistance during bending, but if such a barrier member is installed near the drilling tool, it not only interferes with the drilling process, but also prevents the spiral from forming. There is no guarantee that the chips that are continuously ejected with shapes or undulations will definitely come into contact with the barrier member.Also, there is no guarantee that high-pressure cutting oil is supplied through the inside of the drilling tool and the chips are cut with that pressure. It is also possible to use a gun drill that drains the oil along with the oil, but in that case a special machine tool and tool head are required, and it is not applicable to portable or relatively small drill machines such as drilling machines. be.

[Problems to be Solved by the Invention] When the above-mentioned barrier member is used as a simple means for forcibly cutting the chips that are continuously discharged from the hole,
Not only does this hinder the drilling work, but there is also the problem that the chips tend to be continuously discharged without coming into contact with the barrier member.The present invention fundamentally solves these problems.
It is an object of the present invention to provide a drilling device that can control chips to a predetermined length and discharge them from a hole.

[Means for solving problems]

As a means for solving the above-mentioned problems, the present invention provides a drill spindle equipped with a drilling tool attachment part at the tip.
A pair of thrust rings are supported on the casing so as to be reciprocally movable in the axial direction and are concentrically opposed to each other in the radial direction of the drill spindle, and are respectively fixed to the drill spindle and the casing with a predetermined gap between them; At least three rolling elements are brought into contact with both opposing surfaces of the pair of thrust rings between the thrust rings, their relative positions are regulated by a rolling element support ring, and the rolling elements are rotated in the circumferential direction. The rotor support ring is movably supported and provided on the drill spindle so as to be relatively rotatable following the rolling movement of the rotor.

A plurality of recesses are provided on the rolling track of the above-mentioned rolling elements, with a positional relationship equal to the relative position of the rolling elements regulated by the above-mentioned rolling element support ring, in which all the rolling elements temporarily engage. Adopt the formed structure.

[For production]

In the drill device of the present invention, when the rotors housed in the rotor support ring, which theoretically rotate relative to each other at half the rotational speed of the drill spindle, simultaneously fit into their respective recesses every predetermined rotation of the spindle, then The drill spindle, which applies thrust force to the drilling tool, is slightly displaced in the axial direction in response to the depth of the recess.
Instantly stops cutting with the drilling tool, thereby
Every predetermined rotation of the drill spindle, chips are cut to a predetermined length and discharged from the hole.

〔Example〕

As shown in FIG. 4, the drill device of this embodiment has an electromagnetic adsorption base 2 at the bottom of a drill stand 3, which is fixed to a desired position of a workpiece 1 by electromagnetic adsorption. On the other hand, a punching machine 5 is supported, which can be moved forward and backward relative to the workpiece 1 by rotating an elevator handle 4 or by operating an automatic feed unit (not shown).

As shown in FIG. 1, the drilling machine 5 has an electric motor (not shown) built into a casing 6, and the rotation of the motor shaft 7 is slowed down by two sets of feed gears 8A to 8D, and has an annular cutter or the like at the tip. Drill spindle 10 to which a drilling blade 9 can be attached and detached
to communicate.

The tip of the drill spindle 10 protrudes from a housing block 11 that is screwed and fixed to the lower end of the casing 6, and the middle part of the drill spindle 10 is pivotally supported by a radial needle bearing 12 that is fitted and fixed to the housing block 11. The upper end of the drill spindle 1o is pivotally supported by a radial needle bearing 14 provided on the partition plate 13 of the casing 6. On the drill spindle 10, the portion that can be contacted and supported by the pair of radial needle bearings 12 and 14 is set to be slightly longer than the axial length of the bearings, so that the drill spindle 1O is slightly extended in the axial direction. It is installed so that it can be moved back and forth.

Reference numeral 15 denotes a first thrust ring which is rotatably fixed to the drill spindle 10 located above the radial needle bearing 12, and the outer peripheral surface of the ring receives a thrust load that is curved upwardly and is equal to the curvature of the thrust ball 16. forms a rolling track 17 to be obtained. In the outer circumferential direction of the ring 15, a second thrust ring 18, whose inner circumferential surface faces the rolling raceway 17 with a predetermined gap, is provided in the casing 6.
A rolling track 19 is formed on the inner circumferential surface of the ring 18 to receive a thrust load that is curved downwardly and is equal to the curvature of the thrust ball 16.

20 rotatably includes three thrust balls 16, 16.16 as rolling elements that can roll on the rolling raceways 17 and 19, and individually and concentrically by regulating their mutual relative positions. A sheet metal ball support ring (roller support ring) having a ball accommodation hole 22 that fits into the ball support ring 20. A part of the surface of the thrust ball 16 protrudes from the inner and outer circumferential surfaces of the ball support ring 20, and the rolling raceway 17 and The thrust rings 15 and 18 are placed in a mutually opposing space while being in contact with the thrust rings 19 . The ball accommodation holes 22 are formed at intervals of 120" with respect to the axis of the ball support ring 20. The first thrust ring 15 is spaced between the first thrust ring 15 and the upper end surface of the radial needle bearing 12 via a spacer 25. The first thrust ring 1 is urged in a direction away from the workpiece integrally with the drill spindle 10 by receiving the elastic force of the compression coil spring 26 interposed therein.
5 supports the drill spindle 1o integrated with the second thrust ring 18 in its thrust direction by elastically pressing the thrust ball 16 against the second thrust ring 18. In this way, when the pair of thrust rings 15 and 18 receive thrust load from the drill spindle 10 via the thrust ball 16, the ball support ring 2
The thrust balls 16 supported at zero are able to roll by rolling into contact with the opposing surfaces of the thrust rings 15 and 18, respectively. Therefore, since the relative rolling movement distance of the first thrust ring 15 with respect to the thrust ball 16 is made equal to the rolling movement distance of the thrust ball 16 with respect to the second thrust ring 18, the first thrust ring 15
When rotated, the thrust ball 16, 16.16 becomes
It rolls and moves on the second thrust ring 18 with a stroke that is half the rotation angle of the first thrust ring 15. That is, the three thrust balls 16 supported by the ball support ring 2o rotate relative to each other at a rotation speed that is half the rotation speed of the first thrust ring 15, which rotates together with the drill spindle 10.

On the rolling track 17 of the first thrust ring 15, the thrust balls 1 are arranged at intervals of 120' with respect to the axis thereof.
Three removable spherical recesses 27 are formed at the same depth. Since the relative positions of the three four parts 27 have the same relationship as the relative positions of the three thrust balls 16 supported by the ball support ring 20, the ratio of one rotation to two rotations of the first thrust ring 15 as described above. When the three thrust balls 16, 16.16 are rotated relative to each other together with the ball support ring 20, the three thrust balls 1
6 can be instantaneously engaged with the respective recesses 27 three times for every two revolutions of the drill spindle 10.

Three thrust balls 16, 16, 16 simultaneously move into the recess 2.
7, the first thrust ring 1 is resiliently biased toward the opposite end by the compression coil spring 26.
The drill spindle 10, which is integral with 5, is simultaneously displaced backwards (displaced upwards in FIG. 1) by a distance corresponding to the depth dimension of its recess 27. The depth of the recess 27 is set to be approximately equal to the maximum allowable thickness of the chips to be scraped off by the punching blade 9. The maximum allowable thickness of chips is determined in relation to the maximum rotational speed of the drill spindle 10 and the maximum allowable feed rate of the drilling machine 5, which the drill device has as its maximum drilling capacity, and the material of the workpiece 1. be done. Therefore, when the thrust ball 16 engages with the recess 27 due to the feed force of the drill spindle 10 acting on the drilling tool 9 during drilling, cutting by the drilling tool 9 is momentarily stopped, thereby
The length of the chip will be controlled to a cutting length determined by approximately 2/3 revolutions of the drill spindle 10.

The drilling tool 9 is an annular cutter, and is removably fixed to the cutter aperture 30 of the drill spindle 10 with a set screw 31. On the axis of the drilling tool 9, a pilot bin 32 is installed on the lower end surface of the drilling tool 9. It is inserted so that it can appear freely. When the drilling blade 9 is attached to the drill spindle 10, the head of the pilot bin 32 is pressed by the press piece 34 which receives the elastic force of the compression coil spring 33 housed in the cutter arbor 3o of the drill spindle 10, and the head of the pilot bin 32 is pressed by the press piece 34, which maintains this state. In this case, the tip of the pilot bottle 32 protrudes from the lower end surface of the punching tool 9.
During the drilling process, the cutter arbor 30 is moved upward by rotating idly while in contact with the surface of the workpiece, more precisely, near the surface of the core, according to the feed of the drill spindle 1o, and the drilling process is performed. When the punching machine 5 returns to the upper position after the drilling is completed, the cut pieces are pushed out from inside the punching blade 9 by the elastic force of the compression coil spring 33.

Next, the operation of the above drill device will be explained.

The first thrust ring 15 is formed by pressing the three thrust balls 16 accommodated and supported by the ball support ring 20 toward the second thrust ring 18 in one elastic manner, thereby forming the drill spindle 15 integrated with the ring 15. is supported in its thrust direction.

When the drill spindle 10 is driven to rotate, the thrust ball 16 accommodated and supported by the ball support ring 2o is rotated.
A second thrust ring 18 fixed to the casing 6
The ball rotates at a rate of 1 rotation for every 2 rotations of the drill spindle 10 while rolling in relative rolling contact with the rolling raceway 19 of the drill spindle 10 and the rolling raceway 17 of the first thrust ring 15 that rotates integrally with the drill spindle 10. relative rotation with the support ring 20, thereby causing its thrust ball 1
Three thrust balls 16 move into the three recesses 2 provided on the rolling track 17 three times per one rotation of the ball 6.
7 simultaneously and momentarily. Then, the drill spindle 10 and the first thrust ring 15, which are receiving an elastic force in the opposite direction from the light end by the compression coil spring 26, move in the axial direction by a distance corresponding to the depth dimension of the recess 27, as shown in FIG. , and the state shown in FIG. 1 changes to the state shown in FIG. 3. Therefore, during drilling, the drill spindle 10, which applies a feeding force along the thrust direction to the drilling blade 9 via the rotary operation handle 4 and the automatic feeding unit (not shown), presses the drilling tool 9 into the recess 2.
When it is displaced upward in the axial direction in response to the depth of 7, the movement corresponds to substantially stopping the feed of the punching blade 9 in the cutting direction, and the amount of displacement is scraped away by the punching blade 9. Since this is approximately the same as the maximum allowable thickness of chips, cutting by the drilling tool 9 is stopped instantaneously at the same time, and thereby the chips are controlled to the cutting length determined by 273 rotations of the drill spindle 10. It is intermittently discharged from the hole that is being drilled.

Although the present invention has been described in detail based on the embodiments above, the present invention is not limited to the above embodiments, and can be modified in various ways without departing from the gist thereof.

For example, in the above embodiment, the drill spindle 10 is slidably displaced three times for every two revolutions of the drill spindle 10, but this may be difficult to achieve when an annular cutter with a relatively large cutting diameter is applied. , rolling track 1 of the above embodiment
7, six four parts 27 are formed at intervals of 60@, and the drill spindle 10 can be configured to slide and displace three times per rotation of the drill spindle 10.1 Various drilling operations can be performed. By appropriately setting and combining the number of thrust balls and recesses according to the conditions, the ratio of the number of backward displacements of the drill spindle to the number of rotations of the drill spindle can be increased to 3.
72 or more can be changed in various ways.

Furthermore, the rollers interposed between the pair of thrust rings are not limited to thrust balls, but may be changed to tapered rollers.
Further, the recess into which the rolling element can be fitted may be formed in at least one of the pair of thrust rings.
Further, the drilling blade attached to the tip of the drill spindle is not limited to an annular cutter, but may be a twist drill.

In the above embodiment, the present invention is applied to a drill device equipped with a portable electromagnetic attraction base, but the present invention can also be applied to a small drilling machine or an electric drill.

〔Effect of the invention〕

The drill device of the present invention has a drill spindle having a drilling tool mounting portion at its tip supported by a casing so as to be able to reciprocate along the axial direction, and a pair of drill spindles arranged concentrically opposite each other in the radial direction of the drill spindle. thrust rings are respectively fixed to the drill spindle and casing with a predetermined gap between them, and at least three
A rotor support ring regulates the relative positions of the rotors and supports the rotors so that they can roll in the circumferential direction. 1 and 2 are provided so as to be relatively rotatable following the rolling movement of the rotor, and further, on the rolling track of the rotor, the rotor has a positional relationship equal to the relative position of the rotor regulated by the rotor support ring. A plurality of four parts are formed in which all the rotors temporarily engage, and the rotors accommodated in the rotor support ring, which theoretically rotate relative to each other at half the rotational speed of the drill spindle, maintain the specified rotation of the spindle. When the drill spindle is inserted into each recess at the same time, the drill spindle, which applies thrust force to the drilling blade, is slightly displaced in the axial direction in response to the depth of the recess. According to the invention,
The cutting by the drilling tool can be stopped instantaneously and accurately, thereby cutting the chips into short and long pieces every predetermined rotation of the drill spindle and intermittently discharging the chips from the hole in the process of drilling. Can be done. Therefore, the chips discharged outside the hole do not continue for a long time and the discharge performance deteriorates, and the chips do not get stuck between the hole and the drilling tool, and free cutting is possible as before. It is possible to reliably prevent a situation in which the drilling efficiency is reduced due to loss of performance, or the cutting blade is abnormally worn.

[Brief explanation of the drawing]

The drawings show one embodiment of the drill device according to the present invention, and FIG. 1 is a vertical sectional view around the drill spindle showing the normal state of the drill spindle during cutting, and FIG. 2 is a longitudinal sectional view of the drill spindle when cutting is interrupted. FIG. 3 is a vertical cross-sectional view of the area around the drill spindle showing the state of FIG. FIG. 4 is a schematic front view showing the entire drill device. 5...Drilling machine, 6...Casing, 9...Drilling knife. DESCRIPTION OF SYMBOLS 10... Drill spindle, 15... First thrust ring, 16... Thrust ball (roller), 17...
...Rolling track, 18...Second thrust ring, 19.
... Rolling raceway, 20 ... Ball support ring (roller support ring), 22 ... Ball accommodation hole, 27 ... Recess. Patent applicant Nitto Kohki Co., Ltd. Figure 2 Figure 3 X2□

Claims (1)

[Claims] A drill spindle having a mounting portion for a drilling tool at its tip is supported on a casing so as to be reciprocally movable along the axial direction, and 1 facing concentrically in the radial direction of the drill spindle.
Pairs of thrust rings are respectively fixed to the drill spindle and casing with a predetermined gap between them, and at least three rolling elements are arranged between the thrust rings in contact with both opposing surfaces of the pair of thrust rings. The relative positions of the rollers are regulated by a roller support ring, and the rollers are supported so as to be able to roll in the circumferential direction, and the roller support ring follows the rolling movement of the rollers on the drill spindle. Further, on the rolling track of the rotor,
A drill device in which a plurality of recesses are formed in which all the rotors temporarily engage, with a positional relationship equal to the relative position of the rotors regulated by the rotor support ring.