JPH04223885A - Rotating tool - Google Patents

Abstract

PURPOSE:To easily change over the rotating direction of an output shaft, despite of being small sized and useless load being small. CONSTITUTION:A power transmission part to an output shaft 5 is provided on a carrier 33 or ring gear 32 in a planetary mechanism provided in the power transmission route reaching to the output shaft 5 from a motor, also a changeover means which switches the direction of the rotation transmitted to the output shaft with the rotation check of the carrier 33 or ring gear 32, is provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary tool in which the direction of rotation of an output shaft is changed by axial movement of the output shaft.

0002

[Prior Art] Rotary tools, especially rotary tools for tap-cutting, rotate in the normal direction, and after cutting a predetermined amount, rotate in the reverse direction and return a little. A rotary tool that can perform work efficiently is preferably one in which the output shaft rotates in the normal direction when pressed against the object, and rotates in the reverse direction when released.

A conventional example of a device having such a configuration is shown in FIG.
Shown in 3. A gear 92 is engaged with a pinion 91 attached to the rotating shaft of the motor 9. A gear 95 is engaged with a gear 93 that rotates together with the gear 92, and an output gear 97 is engaged with a gear 96 that is integral with the gear 95. Further, a gear 94 that rotates together with the gears 92 and 93 meshes with an output gear 98 that is disposed coaxially with the output gear 97. The output shaft 99 is slidable in its axial direction and is biased in the protruding direction by a spring 991.Furthermore, on the opposing surfaces of the output gears 97 and 98, there is an engaging member protruding from the output shaft 99. Engagement recesses 970 and 980 are formed in which the engagement protrusion 990 selectively engages.

[0004] The output shaft 99 is pressed against the object.
9 is moved backward against the spring 991, the engagement protrusion 990
Since the motor 9 engages with the engagement recess 970, the rotation of the motor 9 is transmitted to the output shaft 99 along the path shown in FIG. 13(b), and the output shaft 99 rotates in the normal direction. When the output shaft 99 is separated from the object, the output shaft 99 is biased by the spring 991 as shown in FIG. 13(a).
In other words, the engagement protrusion 990 is in the engagement recess 980.
In order to return to the state in which the motor 9 is engaged with the
(c) It is transmitted to the output shaft 99 through the path shown in
9 performs a reversal.

[0005]

[Problem to be solved by the invention] In this case, since it is a combination of a large number of gears, each of which is a spur gear, the overall size inevitably increases.
In particular, the size in the radial direction becomes large. Also gear 9
2, 93, 94 and the gears 95, 96 are arranged in locations different from the line connecting the motor 9 and the output shaft 99, so they are subjected to unbalanced loads when loaded. Since all gears are constantly rotating, that is, gears that do not contribute to power transmission are also constantly rotating, which creates a heavy load and shortens the usable time for those that operate on battery power.

Some motors are designed to change the rotational direction of the output shaft by directly switching the rotational direction of the motor, but in this case, electrical loss occurs in the brushes of the motor, shortening the life of the motor. The present invention has been made in view of these points, and its purpose is to provide a rotary tool that is small in size and has little unnecessary load, yet can easily change the rotational direction of its output shaft. There is something to do.

[0007]

[Means for Solving the Problems] The present invention provides a planetary mechanism in the power transmission path from the motor to the output shaft, and provides a carrier or ring gear in the planetary mechanism with a power transmission section to the output shaft. , is characterized in that it is provided with a switching means that switches the direction of rotation transmitted to the output shaft by blocking rotation of the carrier or the ring gear.

According to the present invention, since a planetary mechanism is used, each member can be arranged coaxially with the output shaft, and at the same time, it is possible to eliminate the situation where unnecessary members are rotating. I can do it.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail based on the illustrated embodiments. As shown in FIG. A tap bit is used to cut threads into an object, and the inside of the housing 1 includes:
As shown in FIG. 6, a motor 10, a mechanism block 2, a switch 70, etc. are housed. 7 in the figure is a battery pack, 7
1 is a switch handle.

The motor 10 and drive block 2 are assembled as a single assembly and incorporated into the housing 1 as shown in FIG. 12
is used as an input section, and the output shaft 5 is used as an output section. In the figure, 11 is a motor mounting base. Based on Figures 1 to 3,
To explain the drive block 2, it has a cylindrical case 20 connected to the rear end side of the motor mount 11, and a stepped cylindrical case 21 connected to the front end side of this cylindrical case 20. A cylindrical case 20 houses a speed reducing part, and a cylindrical case 21 houses a rotation direction switching part.

[0011] The speed reduction section includes a pinion 12 of the motor 10.
A plurality of planetary gears 13 that mesh with the planetary gears 13
The carrier 15 supports the ring gear 14 that meshes with the carrier 14, the carrier 15 that supports the planet gear 13, the planet gear 16 that meshes with the sun gear formed integrally with the carrier 15, the ring gear 17 that meshes with these planet gears 16, and the planet gear 16 that support the planet gear 16. It is composed of a two-stage planetary mechanism consisting of a carrier 18, and of both the ring gears 14 and 17, the ring gear 1
4 is fixed to the cylindrical case 20, while the ring gear 17 is allowed to slide in the axial direction, and in the state shown in FIGS. They are engaged. When the ring gear 17 is moved backward by the slide handle 25 shown in FIG. 3 via the spring 26 and the lever 27, the ring gear 17 and the carrier 15 are engaged and integrated.
The reduction ratio in the reduction section from the motor 10 to the carrier 18 changes.

The rotation direction switching unit housed in the cylindrical case 21 includes a plate 30 rotatably disposed around the outer periphery of the sun gear 19 integrally formed with the carrier 18, and a plurality of plates meshing with the sun gear 19. A planetary gear 31, a ring gear 32 that meshes with these planetary gears 31, and each planetary gear 31.
The carrier 33 supports the slide lever 4, and a pair of slide levers 4.

[0013] The plate 30 here is the carrier 3
A shaft 330 protruding from 3 and supporting the planetary gear 31
It rotates together with the carrier 33, and has a plurality of engagement projections 3 on its outer peripheral surface.
01 are provided protrudingly at equal intervals. And career 33
The ring gear 32 has a spline 330 on its inner circumferential surface, and the ring gear 32 has a plurality of engaging protrusions 321 protruding from its outer circumferential surface at equal intervals, and a spline 320 on its inner circumferential surface at one end. has been formed.

The slide lever 4 is provided with a locking projection 41 at the rear end and a locking projection 42 in the middle, and is supported so as to be slidable in the front and back directions with respect to the cylindrical case 21, and is supported by a spring 40. It is biased forward, and when moving forward, its locking protrusion 41 is engaged with the engaging protrusion 301 of the plate 30, and when retreating, its locking protrusion 42 is engaged with the engaging protrusion 321 of the ring gear 32, and the plate 30 or the rotation of the ring gear 32.

On the other hand, the output shaft 5 supported by the cylindrical case 21 via a bearing 22 so as to be rotatable and slidable in the axial direction is provided with a spline shaft 50 on the rear end side.
A flange 51 is provided near the tip, and a compression spring 52 housed in the carrier 18 comes into contact with the rear end and is biased forward. The spline shaft 50 of the spline 320 of the ring gear 32 is engaged with the spline shaft 50, and when the ring gear 32 moves backward against the compression spring 52, the spline shaft 50 is engaged with the spline 330 of the carrier 33. Further, the tip end surface of the slide lever 4 is in contact with the rear end side surface of the flange 51 via a thrust plate 53.

In the figure, 81 and 82 are thrust plates, 83 is a retaining ring for preventing the output shaft 5 from coming off, and 84 is a ring disposed between the retaining ring 83 and the bearing 22. Therefore, in this rotary tool, if the output shaft 5 is pressed against the object and the output shaft 5 is retreated against the compression spring 52, as shown in FIG.
As shown in , the spline shaft 50 of the output shaft 5 engages with the spline 330 of the carrier 33, and the carrier 33 and the output shaft 5 rotate together, and are pressed by the flange 51 of the output shaft 5. The slide lever 4, which is moved back against the spring 40, locks the locking protrusion 4 in the middle of the slide lever 4.
2 is engaged with the engagement protrusion 321 of the ring gear 32 to stop the rotation of the ring gear 32.

If the motor 10 is rotated in this state, the output of the reduction unit, that is, the rotation of the sun gear 19 integrated with the carrier 18, will mesh with the sun gear 19 and the ring gear 32 whose rotation is stopped, and the sun gear will rotate. The carrier 33 transmits the revolution movement of the planetary gear 31, which rotates and revolves along with the rotation of the planet gear 19, to the output shaft 5. As a result, the output shaft 5 rotates in the normal direction.

When the output shaft 5 is moved away from the object, the output shaft 5 returns to its original position due to the compression spring 52.
As shown in FIG. 1, the spline shaft 50 engages with the spline 320 of the ring gear 32, causing the ring gear 32 and the output shaft 5 to rotate together, and the slide lever 4 to be returned by the spring 40. Accordingly, the locking protrusion 41 at the rear end of the slide lever 4 engages with the engaging protrusion 301 of the plate 30, and the rotation of the plate 30 and carrier 33 is stopped. For this reason, the rotation of sun gear 19 is
It is transmitted to the ring gear 32 and the output shaft 5 via the planetary gear 31, which only rotates on its own axis, and the output shaft 5 performs reverse rotation.

If the number of teeth of the sun gear 19 is Za and the number of teeth of the ring gear 32 is Zc, the reduction ratio Pn of the output shaft 5 with respect to the sun gear 19 during forward rotation is Pn=Za/(Za+Zc), and when the rotation is reverse rotation At this time, the reduction ratio Pr of the output shaft 5 with respect to the sun gear 19 is Pr=Za/Zc.

At this time, it is desirable to set both of the reduction ratios so that the rotational speed of the output shaft 5 is higher during reverse rotation than during forward rotation. This is because a stronger torque is required when rotating in the normal direction for screw tightening, drilling, and even tapping. Figures 7 to 9
shows another example. This means that the spline shaft 50 provided on the output shaft 5 and the spline 320 provided on the ring gear 32 are always engaged, and that the carrier 33 is slidable in the axial direction and that a compression spring disposed inside the carrier 18 is used. 52, and an engagement recess 32 formed in the inner wall of the ring gear 32 when the ring gear 32 moves forward is placed on the front surface of the carrier 33, which is in contact with the rear end surface of the output shaft 5.
2 is provided with a locking protrusion 332 that engages with. In addition, the plate 30 here is fixed to the cylindrical case 21 so that it does not rotate, and only when the carrier 33 retreats against the compression spring 52 is the shaft that supports the planetary gear 31. 330 is fitted into the shaft hole 300 to stop the rotation of the carrier 33. Note that a member corresponding to the slide lever 4 in the above embodiment is not provided.

In this case, when the output shaft 5 is moved backward, the carrier 33 pushed by the output shaft 5 moves backward against the compression spring 52 and engages the ring gear 32, as shown in FIG. When the engagement with the carrier 33 is released, the rotation of the carrier 33 is stopped via the plate 30, and the rotation of the sun gear 19 is stopped by the planetary gear 3.
1 is transmitted to the ring gear 32, and the output shaft 5 rotates together with the ring gear 32 in the normal rotation direction. At this time, the reduction ratio Pn of the output shaft 5 with respect to the sun gear 19 is Pn=
It becomes 1/Zc/Za.

When the force pressing the output shaft 5 against the object is removed, the compression spring 52 moves the carrier 33 and the output shaft 5 forward, as shown in FIG.
At the same time as the rotation is released from the rotationally fixed state, the ring gear 32 engages with the ring gear 32 and rotates together with the ring gear 32. In other words, since the carrier 33 supporting the planetary gear 31 that meshes with the sun gear 19 is directly connected to the output shaft 5 via the ring gear 32, the rotation of the sun gear 19 is directly transmitted to the output shaft 5, and the output shaft 5 Perform a reversal. In other words, the reduction ratio Pr of the output shaft 5 with respect to the sun gear 19 is 1. The reverse rotation is faster than the forward rotation, and when considering tap cutting operations, the return operation can be performed quickly.

Still other embodiments are shown in FIGS. 10 to 12. This is a configuration in which a torque limiter (safety clutch) is added to the first embodiment, and the stepped cylindrical case 2
A steel ball 70 is disposed in the hole penetrating the stepped portion of the ring gear 32, and a spring 71 is disposed between the steel ball 70 and the flange 51 of the output shaft 5. An engaging portion 325 with which the ball 70 engages is formed.

Now, if the output shaft 5 is moved back by pressing it against the object, the spline shaft 50 of the output shaft 5 will align with the spline 33 of the carrier 33, as shown in FIG.
0, the carrier 33 and the output shaft 5 rotate together, and the spring 71 pressed by the flange 51 of the output shaft 5 moves the steel ball 70 to the ring gear 32.
The ring gear 3
The rotation of motor 2 is stopped, and in this state motor 1
0, the rotation of the sun gear 19 is caused by the rotation of the planetary gear 31, which meshes with the sun gear 19 and the ring gear 32 whose rotation is stopped, and rotates and revolves as the sun gear 19 rotates. The signal is transmitted to the output shaft 5 by the carrier 33, and the output shaft 5 rotates in the normal direction.

During normal rotation of the output shaft 5, when the load torque that tries to stop the rotation of the output shaft 5 increases, a braking force is also applied to the carrier 33 which is synchronized with the output shaft 5, and drives the carrier 33. If this becomes difficult, the driving force that the planetary gear 31 applies to the ring gear 32 also increases, and the force of the planetary gear 31 trying to drive the ring gear 32 acts between the ring gear 32 and the steel ball 70. When the frictional force becomes larger than the friction force, the ring gear 32 pulls the steel ball 70 against the spring 7.
In order to start rotating while pushing back against 1, the output shaft 5
The driving force is no longer transmitted to.

If the output shaft 5 is pressed against the object and rotated in the normal direction, when the output shaft 5 is moved away from the object, the output shaft 5 is returned by the spring 70, so that the output shaft 5 rotates normally as shown in FIG. The spline shaft 50 engages with the spline 320 of the ring gear 32, and the ring gear 32 and the output shaft 5 rotate together, and as the slide lever 4 is returned by the spring 40, the slide lever 4 is rotated. The locking protrusion 41 at the rear end is the engagement protrusion 301 of the plate 30.
The plate 30 and the carrier 33 are stopped from rotating. Further, at this point, the pressing force of the steel ball 71 by the spring 70 is removed, so the ring gear 32 becomes free to rotate. For this reason, the rotation of the sun gear 19 is transmitted to the ring gear 32 and the output shaft 5 via the planetary gear 31, which only rotates on its own axis, and the output shaft 5 rotates in reverse.

Instead of the locking protrusion 42 provided on the slide lever 4 in the first embodiment, a torque limiter is used to press and fix the ring gear 32. In each of the above embodiments, forward rotation and reverse rotation are switched by the axial movement of the output shaft 5 when the output shaft 5 is pressed against the object, but a separate operation for switching is required. It is also possible to provide a switch and manually operate the switch to switch between forward and reverse directions, regardless of whether or not the output shaft 5 is pressed against an object.

[0028]

[Effects of the Invention] As described above, since the present invention utilizes a planetary mechanism, each member can be arranged coaxially with the output shaft, making it easy to downsize, especially to reduce the diameter. Moreover, because it eliminates the need for unnecessary parts to rotate, it can be used for long periods of time even in devices that have a small load and operate on battery power. Furthermore, since the direction of rotation of the motor itself is not changed, the life of the motor can be extended.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment when reverse rotation is performed, in which (a) is a longitudinal cross-sectional view and (b) is a cross-sectional view taken along the line A-A.

FIG. 2 shows one embodiment during normal rotation, in which (a) is a longitudinal cross-sectional view and (b) is a cross-sectional view taken along the line B-B.

FIG. 3 is an exploded perspective view of one embodiment.

FIG. 4 is a sectional view of a motor and a mechanism block of one embodiment.

FIG. 5 is a side view of one embodiment.

FIG. 6 is a cutaway side view of one embodiment.

FIG. 7 shows another embodiment when reversed; FIG. 7(a) is a longitudinal cross-sectional view, and FIG. 7(b) is a cross-sectional view taken along the line C--C.

FIG. 8 is a longitudinal cross-sectional view showing another embodiment during normal rotation.

FIG. 9 is an exploded perspective view of another embodiment.

FIG. 10 shows another embodiment when reversed; (a)
is a vertical cross-sectional view, and (b) is a cross-sectional view taken along the line D-D.

FIG. 11 is a longitudinal sectional view showing another embodiment during normal rotation.

FIG. 12 is an exploded perspective view of another embodiment.

FIG. 13 shows a conventional example, (a) is a sectional view, (a) is a cross-sectional view;
b) is an explanatory diagram for normal rotation, and (c) is an explanatory diagram for reverse rotation.

[Explanation of symbols]

5 Output shaft 32 Ring gear 33 Career

Claims (4)

[Claims] Claim 1: A planetary mechanism is provided in the power transmission path from the motor to the output shaft, and a carrier or ring gear in the planetary mechanism is provided with a power transmission part to the output shaft, and the rotation of the carrier or ring gear is blocked to prevent output. A rotary tool characterized by being provided with a switching means for switching the direction of rotation transmitted to the shaft. 2. The rotary tool according to claim 1, wherein the switching means is operated by axial movement of the output shaft. 3. The rotary tool according to claim 1, wherein the rotary tool has a reduction ratio that makes the reverse rotation speed of the output shaft higher than the normal rotation speed. [Claim 4] A claim characterized in that the output shaft is attached with a tap cutting tool, and the planetary mechanism also serves as a component of a safety clutch that disconnects the output shaft from the motor side when load torque increases. The rotary tool according to item 1.