JPS6030845A - Transmission gear of motor-driven driver - Google Patents

Abstract

PURPOSE:To provide a device which can automatically make shifting between two different transmission outputs, one being a high speed transmission output and the other being a low speed transmission output, in response to a load through a simple structure without the need for gear shifting operation, by installing an auxiliary coil which slides a slide gear against the magnetic force emanating from a permanent magnet. CONSTITUTION:A slide gear 20, gearing with an internal gear 17, is located so that it can freely engage with and disengage from the shaft 21 of a planetary gear 16. The slide gear 20 is forced to perform a repulsion action against magnetism emanating from permanent magnets 24 and 26, and this causes magnetic energization of the slide gear 20 to either of the permanent magnets to fix the internal gear 17 and the planetary gear 16, and the planetary gear 16 revolves at a high speed through integrated rotation of such gears to produce a high speed transmission output. When a motor is increased in its load and a high currnet flows to the motor 8, an auxiliary coil 29 is naturally excited, the slide gear 20 is slid in an opposite direction against the magnetic force of the permanent magnets 24 and 26 through the exciting action, and the planetrary gear 16 forms a planetrary gear reduction mechanism, which revolves at a low speed, to produce a low speed transmission output.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a transmission device for an electric screwdriver that automatically takes out a transmission output through a planetary gear intermediate groove.

(B) Background of the Invention The small electric screwdrivers that have been used in the past are mainly used for relatively light-load turning operations with high-speed, low-torque rotation, but depending on the conditions of use, even small electric screwdrivers may be used. In recent years, electric screwdrivers that can rotate at low speed and high torque have been provided because there is a desire for a screwdriver that can produce high torque output.

However, in this case, because of its small size, it was not possible to obtain the desired high torque output. When changing gears, it was necessary to change the gear each time, which significantly reduced work efficiency.In addition, the structure was complicated due to the transmission mechanism and its transmission switching mechanism, which required many gears. Moreover, it has the problem of increasing its size and cost.

(c) Purpose of the Invention Therefore, the present invention provides an electric driver that can automatically switch different types of transmission output between high speed and low speed according to the load without requiring a speed change operation or complicating the structure. The purpose is to provide transmissions for

(D) Summary of the Invention This invention enables both high-speed conduction output and low-speed conduction output to be taken out via a compact planetary gear mechanism that produces high output, and automatically as appropriate depending on the intended use. It is characterized by a transmission device for an electric screwdriver that can switch between high and low speed transmission output.

(E) Effects of the Invention According to the present invention, a slide gear that meshes with an internal gear is provided so as to be able to engage and disengage from the shaft of a planetary gear, and the slide gear is caused to perform the magnetic repulsion of a permanent magnet. As a result, the internal gear and the planetary gear are fixed by magnetically biasing the slide gear in one direction, and by the integral rotation of these gears, the planetary gear can revolve at high speed and a high-speed transmission output can be obtained. Also, when the load on the motor increases and a large current flows through the motor,
The auxiliary coil is naturally excited, and the excitation action of this coil causes the slide gear to slide in the other direction against the magnetic force of the permanent magnet, disengaging from the shaft of the planetary gear and allowing the planetary gear to rotate. As a result, the planetary gear becomes parallel to the planetary gear decelerating ta rotating at a low speed, and the low-speed transmission output can be increased by 1q.

Therefore, when using an electric screwdriver, a constant voltage current flows through the motor during rotation operation with a relatively light load, and the rotation is suitable for the relatively high-speed rotated object under the high-speed, low-torque transmission output. You can perform dynamic operations. Also, when a high load is applied to the motor, a large current flows through the motor, and in response to this, the slide gear automatically slides to perform rotational operation of low-speed, high-torque transmission output. can.

In this way, rotation operations can be performed with the required torque output according to the conditions of use, which is particularly effective when torque conversion is required at any time, and a series of rotation operations can be performed from beginning to end with one electric screwdriver. Become a highly capable driver with good work efficiency.

Furthermore, since the gear changeover mechanism is automatic, the changeover is performed only by the sliding operation of the slide gear V, so it can be done with a simple configuration.

(f) Examples of the invention An embodiment of the present invention will be described in detail below based on the drawings.

The drawings show an electric screwdriver, and in FIG. 1, an electric screwdriver 1 has a chuck 2 at its tip for gripping.

The casing 3 is formed into a cylindrical shape, and has an operating barrel 4 at its tip for setting the load on the torque limiter.By rotating the operating barrel 4 in accordance with a scale, the load on the output shaft is set. . A grip part 5 is provided in a row at the middle lower part of the casing 3, and a trigger 6 is provided on the front surface of the base of the grip part 5, and this trigger 6 operates to turn the power on and off.

A forward/reverse rotation selector switch 7 for the forward/reverse motor is provided on the side surface of the intermediate portion of the casing 3, and by operating the switch 7 in the vertical direction, the motor can be switched between forward rotation, stop, and reverse rotation. Note that since the switch 7 is internally configured in a ring shape, the switch 7 is also provided on the opposite side surface of the casing 3.

This electric screwdriver 1 uses a battery as a power source,
This battery is arranged to be housed in the rear end of the casing 3 as appropriate.

In FIG. 2, τ2? is fixed within the casing 3? h
Fresh 3: Iy O/T* IJJ -h I+ft
! Holle l Tsuka Niyushi M Ta Km dr.

A first planetary gear reduction gate mechanism 9 with a continuous output, and second, third, etc. that reduce the speed to a constant speed and are successively installed in the succeeding stage.
The power is transmitted to the output shaft 11 through the planetary gear reduction mechanism 10, and as a result, the gear 2 is rotated.

Each of these reduction mechanisms 9, 10, . The motor 8 is housed in an inner gear case 13 opposite to the motor 8.

This first planetary gear reduction mechanism 9 includes a first planetary gear 1 connected to a first sun gear 15 which is rotatably attached to the end of the main shaft 14 of the motor 8.
6 are equally spaced in the circumferential direction and mesh with each other, and these first planetary gears 16 mesh with the first internal gear 17 and are allowed to revolve.

The first planetary gear 16 described above has each gear shaft connected to the first planetary gear 16.
The gears 16 are fixed to a gear carrier 18, and the revolution outputs of these gears 16 are transmitted to the second planetary gear reduction mechanism 10 at the subsequent stage via an intermediate output shaft 19 that is integrated with the first carrier 18.

A slide gear 1!20 that slides in the axial direction is fitted onto the main shaft 14 of the motor 8 mentioned above, and this slide gear v2
0 meshes with the first internal gear T-17, has a recess 23 on one end surface for fitting the protrusion 21 of the first planetary shaft 22, and has a permanent magnet 24 and a locking protrusion 25 on the other end surface.
It is equipped with

The above-mentioned protrusion 21 has a cone-shaped tip and serves to create a sliding action that allows the concave portion 23 to fit lightly into the corresponding concave portion 23 and to be easily removed.

The above-mentioned permanent magnet 24 is integrally fitted into the exposed end surface of the central portion of the slide gear 1720, and the permanent magnet 26 is similarly exposed on the end surface of the boss portion 8a on the motor 8 side facing this. The permanent magnets 24 and 26 are separated by the magnetic repulsion of both permanent magnets 24 and 26, and the slide gear 20 can be moved in any direction along the main shaft 14 by the magnetic repulsion and the action of a magnetic circuit described later. Slide operation is performed.

The above-mentioned opposing permanent magnets 24 and 26 have the same magnetic poles facing each other and are set in a magnetic anti-light state, so that the slide gear 20 is normally magnetically biased in a direction that separates from the motor 8 side and reverses it. The protrusion 21 of the first planetary shaft 22 is fitted and locked in the end face recess 23 on the opposite side of the slide gear 20, and the rotation of the first planetary gear 16 is locked. Therefore, if power is transmitted in this state, only the high-speed revolution of the first planetary gear 16 will result in a high-speed transmission output.

When obtaining low-speed conduction output, slide key *r2
0 slides and both permanent magnets 24.2G are in contact with each other. 27, the slide gear 20 is provided in a fixed state in which rotation is stopped, and at this time, the slide gear 20 is unlocked from the first planetary shaft 22, and the first planetary gear 16 is allowed to rotate. By transmitting power in this state, relatively low-speed transmission output can be obtained.

The above-mentioned locking protrusion 25 is provided with a spring so as to be movable forward and backward on its corresponding side, and is configured to promote a stable shock absorbing effect when it is locked with the corresponding locking portion 27.

Above) Slide operation of Slight Gear A-20 is performed using main shaft 1.
This is done by energizing an auxiliary coil 29 for guiding the slide gear that is wound around the outer circumference of the boss portion 8a of the motor 8 via an annular frame 28. The current generated from inside the motor is
Motor case 8b which is a conductor, inner gear case 13 annular frame 28, first internal gear 17, slide gear 2
0, both permanent magnets 24. '26, a magnetic circuit is constructed that circulates around a so-called auxiliary coil 29 that flows through each of the boss portions 8a, and the auxiliary coil 29 is excited by the generation of this magnetic circuit.

By the way, when the auxiliary coil 29 is excited, when the load on the rotated body increases when the electric screwdriver 1 is used and a large current is generated in the motor 8, the magnetic repulsion force is greater than the magnetic repulsion force of the permanent magnet. A magnetic circuit is generated to excite the auxiliary coil 29, and the slide gear 20 is slid by the excitation action of this magnetic circuit.

In addition, in the separation operation between the slide gear 20 and the boss portion 8a, it is possible to use a spring instead of a permanent magnet, but in this case, the frictional resistance at the supporting contact surfaces at both ends of the spring is high. Therefore, it is not preferable to use a permanent magnet.

The 23rd mentioned above! The i2 star gear reduction mode 4!610 includes a second lean gear 30 that is pivotally attached to the intermediate output shaft 19, and a second lean gear A that meshes with this gear and is equally spaced in the circumferential direction.
31, a second internal gear 32 meshing with the second planetary gear 31, and a second carrier 34 integral with the second planetary shaft 33.

The decelerating rotational force from the intermediate output shaft 19 is further decelerated through these gears, and the power is transmitted to the second carrier 34. (omitted) are arranged in series so that the output shaft 11 has a predetermined deceleration rotation speed.

A ball locking protrusion 35 is formed around the side surface of the second internal gear 32 facing the motor 8, and a ball 37 supported by a ball support plate 36 abuts between these protrusions 35. The ball 37 is urged toward the ball locking protrusion 35 by three springs via the receiving plate 38, thereby forming a ball clutch 40.

The above-mentioned ball clutch 40 can set a torque limiter by adjusting the biasing force of the spring 39.
The biasing force of the three springs is adjusted by moving the second internal gear 32 toward the ball side.

In the figure, 41, 42, and 43 are spacers, and 44 is a bearing.

FIG. 3 shows an electric circuit, in which a forward/reverse changeover switch 7 switches the polarity of a forward/reverse motor 8 to operate a forward/reverse motor. The auxiliary coil 29 is interposed between the positive side of the battery 45 and the trigger 6.

When tightening bolts, nuts, etc. using the electric screwdriver configured in this way, operate the forward/reverse selector switch 7 from the neutral stop position i row to the desired forward or reverse direction of rotation, and then turn the trigger 6 ONJ Ru. trigger 6
When the motor 8 rotates in the forward or reverse direction due to the operation of Power is transmitted to.

At this time, the slide gear 20 is magnetically energized at the 1st M star gear deceleration 1 side 9, and the first planetary gear t-16
It is in a state of high-speed transmission output with its rotation locked, and the tightening operation is performed under conditions of high-speed rotation suitable for initial tightening such as so-called Pol 1, which allows rotation under light loads, and is tightened carefully. .

When the fastening load increases as desired, the auxiliary coil 29 is automatically excited, and accordingly, the slide gear 1720
slides from 1 to 1 in response to the generation of a magnetic circuit, and the first planetary gear 16, which was locked to this slide gear 20, is unlocked and this gear 16 is allowed to rotate, and rotates at a low speed to complete the rotation. The output is switched to low-speed, high-torque transmission output that is decelerated. Therefore, in the tightening operation of bolts, etc., the high torque required at the end of tightening can be automatically obtained, and a rotation operation suitable for the tightening operation can be obtained with one electric screwdriver.

In the above-mentioned embodiment, the tightening operation of a rotating object such as a bolt is taken as an example, but this is not limited to the tightening operation of a rotating object such as when removing a bolt or the like, as well as other rotating objects for which torque exchange is desired. It can be applied to rotational operations.

[Brief explanation of drawings]

The drawings show one embodiment of the invention, and FIG. 1 is a side view of an electric screwdriver. FIG. 2 is an enlarged vertical sectional view of the main parts of the transmission. FIG. 3 is its electrical circuit diagram. 1... Electric screwdriver 9... First planetary gear reduction mechanism 15... First sun gear 16... First planetary gear 17... First internal gear 18... First carrier 20... Slide gear 22
...First planetary shaft 23...Concave portion 24.26...Permanent magnet 29...
・Auxiliary coil Fig. 2 1 Fig. 3

Claims (1)

[Scope of Claims] 1. A planetary gear, which is equipped with a zanghi 11 connected to the main shaft of the motor, a planetary gear 17 that meshes with it, and an internal gear that meshes with the planetary gear, and that outputs a gear change output from the rear gear that supports the planetary gear. A transmission device for an electric screwdriver equipped with a gear reduction mechanism, which meshes with the internal gear and, while maintaining this mesh, slides as far as the shaft of the brane gear t. a slide gear that engages with a stopping engagement part whose rotation is stopped, and a pair of permanent gears that face each other with the same magnetic poles on mutually opposing surfaces of the slide gear and the boss part of the motor. Magnet, Candy @ Core,; Noge, 4I' Poison, 9^Pay also [M Kerosuke], excite the magnetic circuit based on the increased load on the motor and the large current flowing through the motor, and permanently A transmission device for an electric screwdriver equipped with an auxiliary coil that slides a slide gear in a direction to disengage it from a shaft of a planetary gear against the magnetic force of a magnet.