JPS6034275A - Variable speed gear for motorized driver - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 outputs a transmission output via a planetary gear mechanism.

(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, there is a limit to the torque output due to its configuration, making it impossible to obtain the desired high torque output and being unable to apply it to a wide range of rotational work, resulting in a decline in work efficiency. was.

Further, in terms of its output structure, the 4M construction has the problem of being complicated and large due to the transmission mechanism requiring many gears and its transmission switching mechanism, resulting in high cost.

(c) Purpose of the Invention Therefore, the object of the present invention is to provide a transmission device for an electric screwdriver that can easily obtain different transmission outputs for high speed and low speed without complicating the structure.

(D) Summary of the Invention This invention is capable of extracting both high-speed conduction output and low-speed conduction output via a small-sized, high-output planetary gear mechanism and switching to high-speed and low-speed conduction output as appropriate. It is characterized by being a transmission device for an electric screwdriver.

(E) Effects of the Invention According to the present invention, the slide gear, which is provided so as to be able to engage and disengage from the shaft of the planetary gear, can be fed by an operating piece external to the driver via the mechanism. It can be easily slid between the engagement side and the disengagement side. When the sliding operation is made to the engagement side, this slide gear fixes the internal gear and the planetary gear, causing these gears to rotate as one.The planetary gear revolves at high speed and generates a high-speed transmission output of 1η. I can do it. In addition, when the IC is operated by sliding to the wi-out side, the engagement with the shaft of the planetary gear is released and the rotation of the planetary gear is allowed, so the planetary gear performs a planetary gear deceleration motion of low-speed revolution, and low-speed transmission output can be obtained. .

Therefore, when using an electric screwdriver, when the load is light, the operation piece should be moved to one side to obtain a high-speed, low-torque transmission output to perform a rotation operation suitable for a high-speed rotated object. When the load is high, the operating piece can be operated on the other side so as to obtain a low-speed, high-torque transmission output, and the rotational operation suitable for the rotated body can be performed.

In this way, the electric screwdriver can be used by adjusting the required torque output according to the conditions of use, resulting in a high-performance electric screwdriver with good working efficiency. However, not only can the speed change operation be performed from the outside with a single touch, but the internal switching mechanism can be performed only by sliding the slide gear, so it can be provided with a simple configuration.

Additionally, if the slide gear feeding mechanism is equipped with a slide function that automatically slides the slide gear based on a high load being applied to the driver, it will be possible to automatically switch to the desired high torque transmission output. .

Furthermore, if it is equipped with a locking mechanism for fixing the slide position,
It can also be set and used exclusively for high-speed or low-speed conduction output.

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

The drawing shows an electric screwdriver, and in FIG. 1, an electric screwdriver 1 has a chuck 2 at the tip, and this chuck 2
holds various rotating tools (not shown).

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 provided so as to be housed in the rear end of the casing 3 as appropriate.

In FIG. 2, is the output of the forward/reverse motor 8 fixed in the casing 3 different between high speed and low speed? ! A first planetary gear reduction mechanism 9 with a variable-speed output, and second, third, etc. idler gear reduction mechanisms 10 that decelerate to a constant speed and are sequentially installed in the succeeding stage. Power is transmitted to the output shaft 11 through the output shaft 11, and as a result, the chuck 2 is rotated.

Each of these reduction mechanisms 9, 10... is housed in an outer gear case 12 fitted into the casing 3.
The motor 8 is installed inside the annular motor mounting plate 13 fixed inside the
It is built in opposite to.

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 above-mentioned first planetary gear t-16 has each gear shaft fixed to the first carrier 18, and the revolution output of these gears 16 is transmitted to the subsequent stage through the intermediate output shaft 19 which is integrated with the first carrier. The power is transmitted to a two-planetary gear reducer 1M10.

−7= A slide gear 20 that slides in the axial direction is fitted onto the main shaft 14 of the motor 8, and this slide gear 20
meshes with the first internal gear 17, while the motor 8
The protrusion 21 of the first planetary shaft 22 is on the opposite end surface.
It is provided with a recess 23 for engaging.

The above-mentioned protrusion 21 has a conical tip and serves to generate a sliding action such that it is lightly engaged with and easily removed from the corresponding recess 23. For this reason, when a high load is applied to the driver, it is set so that it automatically disengages in response to the load pressure via the internal deceleration mechanism.

The above-mentioned sliding operation of the slide gear 20 is performed by operating an operation piece 25 provided outside the driver which is linked to the feed mechanism 24 of the slide gear 20. This feed mechanism 24 is shown in FIG. As also shown,
It is composed of a feed screw 26, an operating ring 27 for operating the same, an operating piece 25 integrated therewith, and a click bin 2-8-8 for regulating its operating position.

The above-described feed screw 26 is formed into a stepped cylinder having a small diameter portion and a large diameter portion, and the small diameter portion is fitted onto the small diameter shaft portion of the slide gear 20 via a ball bearing 29. The slide gear 20 moves integrally in the axial direction and functions as a feeding member, but is connected in the circumferential direction with a ball bearing 29 blocking rotational force. On the other hand, the large diameter portion has several feed screws 26a with a large feed pitch protruding from the inner peripheral surface, and these feed screws 26a engage with feed grooves to be described later to allow axial feed. Ru.

Further, a guide protrusion 26b is provided on the outer circumferential surface to protrude in the axial direction, and this protrusion 261) is provided so as to be engaged with a guide groove 138 carved in the axial direction of the motor mounting plate 13 so as to slide in the axial direction. . In addition, there are two notches 26 in the circumferential direction of the large diameter part.
c, 26b, and has a notch for avoiding the connection rod and click bin, which will be described later.

” The series of operating rings 27 includes an engaging protrusion 27 protruding from the inner circumferential surface.
A is rotatably provided around the boss portion 8a of the motor 8 by engaging with a groove 8b carved around the boss portion 8a of the motor 8, and the above-mentioned feed screw 26a and a screw are provided on the outer peripheral surface. It has a matching feed groove 27b. In addition, these feed screws 2
6a and the feed groove 27b are set to correspond to the length of the slide gear v20 that slides into and out of engagement with the first planetary shaft 22.

In addition, a connecting rod 27c is provided protruding from one side of the outer peripheral surface.
This connecting rod 27c is connected to one notch 26 of the feed screw 26.
An operating piece 25, which is exposed to the outside of the driver, is fixed to the outer end of the driver. This operation piece 25 is installed by cutting out the inside of the casing 3 so as to be movable in the circumferential direction in accordance with the feed length, and when rotated to one side or the other side,
The operation ring 27 and the feed screw 26 are interlocked with this, and the slide gear 20 is slid in any direction along the main shaft 14. A regulating protrusion 27d corresponding to the click bin 28 is provided on the other side of the outer circumferential surface so as to protrude in correspondence with the other notch 26d of the feed screw 26 described above.

-10- The click bottle 28 described above is inserted into the bottle holding hole 13b of the motor mounting plate 13, biased by a coil spring 28a to align the tip of the bottle with the regulating protrusion 27d, and when the operating ring 27 is rotated. In addition to positioning the operation piece 25, it also serves to clarify the operation feel when switching the operation piece 25. By the way, the biasing pressure of the click bin 28 is such that when a high load is applied when using a screwdriver, the regulating protrusion 27d of the operating ring 27 automatically returns to its original state against the biasing pressure of the click bin 28 in response to this load pressure. The biasing pressure is set to be lower than the high load of the driver so that the output is automatically switched to low speed and high torque output when the driver is under high load.

Note that when the slide gear 20 slides in the direction of disengaging from the first planetary shaft 22, a fixed gear 130 is formed on the motor mounting plate 13 to mesh with the slide gear 1720 in order to stop the rotation of the slide gear 1720 at that sliding position. are doing.

Therefore, when the engagement with the first planetary shaft 22 is released, the slide gear 20 meshes with both the fixed gear 130 and the first internal gear 17 to rotate the first internal gear 17. It is a low-speed revolution that is regulated.

Using the feed mechanism 24 configured in this way, the operation piece 2
5 is operated to one side, the end face recess 23 of the slide gear 20 engages and fixes the protrusion 21 of the eleventh planetary shaft 22, and the rotation of the first planetary gear 16 is restricted. If the power is transmitted by the first planetary gear 16, only the high-speed revolution of the first planetary gear 16 will result in a high-speed transmission output.

In order to obtain a low-speed conduction output, 1q is generated when the operation piece 25 is operated to the other side. In this case, the slide gear 20 meshes with the fixed gear 13c, and the slide gear 20 and the first internal gear 17 is in a fixed state where rotation is stopped, while the slide gear v20 is installed in the first position.
If the fixation to the planetary shaft 22 is released and the first planetary gear 1716 is allowed to rotate, and power is transmitted in this state, a relatively low-speed transmission output can be obtained.

The above-mentioned second planetary gear reduction mechanism 10 includes a second sun gear 30 that is rotatably attached to an intermediate output shaft 19, a second planetary gear 31 that meshes with this gear and is equally spaced in the circumferential direction, and a second sun gear 31 that is equally spaced in the circumferential direction. A second internal gear 32 that meshes with the second planetary gear 31, and a second internal gear that is integral with the second planetary shaft 33.
It consists of a carrier 34.

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 is in contact between these protrusions 35. However, this ball 37 is urged toward the ball locking protrusion 35 by the spring 39 via the receiving plate 38,
A ball clutch 40 is configured.

In the ball clutch 40 described above, the 1-ruke limiter 13- can be set by adjusting the biasing force of the spring 39, and adjusting the biasing force of the spring 39 is achieved by moving the second internal gear 32 toward the ball side. This is done by adjusting the amount of

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

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 to the desired forward or reverse direction of rotation, and then turn the trigger 6 ON. do. When the motor 8 rotates in the forward or reverse direction by operating the trigger 6, the output of the motor 8h) is sequentially transmitted to the output shaft via the cylinder 1, the second planetary gear reduction mechanism 9, 10, etc. Power is transmitted to 11.

At this time, if the operating piece 25 is set to the low torque side as shown in FIG. In this state, the fastening operation can be performed under conditions of high-speed rotation suitable for initial fastening of so-called bolts that allow rotation under light loads.

-14- When the fastening load gradually increases, the reduction mechanism receives load pressure, and the slide gear 20 moves due to the sliding action by the protrusion 22 of the first planetary gear 16 and the automatic return action against the click bin 28. As shown in FIG. 4, the first planetary gear 16 that had been engaged with the slide gear 20 is disengaged, allowing the gear 16 to rotate at a low speed and fully rotate. Switched to reduced speed, high torque transmission output. therefore,
When tightening bolts, etc., the high torque required at the end of tightening is automatically increased to 1q, and a rotation operation suitable for the tightening operation can be obtained with one electric screwdriver.

(g) Other Examples FIG. 5 shows another embodiment of the present invention, which is equipped with a locking mechanism 51 for fixing the slide gear in sliding positions on the high-speed transmission output side and the low-speed transmission output side. , this locking mechanism 51 is equipped with an auxiliary operation piece 53 that converts the biasing pressure against the click pin 52, and when this auxiliary operation piece 53 is set to the high biasing pressure side to press the ball 54, It can be locked and used exclusively for high-speed, low-torque transmission output, and when set to the low biasing pressure side, the locking mechanism 5 is released, allowing automatic transmission output switching according to the high load of the driver, similar to the above-mentioned embodiment. Effect can be obtained.

[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 longitudinal sectional side view of the main parts of the transmission. Figure 3 is an enlarged longitudinal sectional front view of the main part. Figure 4 is an enlarged longitudinal sectional side view of the main part of A. FIG. 5 is an enlarged vertical sectional front view of the main parts of a transmission showing another embodiment of the present invention. 1... Electric screwdriver 9... First planetary tooth width reduction mechanism 15... First sun gear 16... First planetary gear 17... First internal gear 18... First carrier 20...・Slide gear 22
...First planetary shaft-16-23...Concave portion 24. ...Feeding mechanism 25...Operation piece 51...Lock mechanism -17-

Claims (1)

[Scope of Claims] 1. A planetary tooth width reduction mechanism that includes a Zang gear connected to the main shaft of the motor, a planetary gear that meshes with the Zang gear, and an internal gear that meshes with the planetary gear, and extracts a variable speed output from a carrier that bears the planetary gear. The transmission device for an electric screwdriver is provided with a slide gear that meshes with the internal gear and engages and disengages from the shaft of the planetary gear while maintaining this meshing, and the slide gear is provided on an engagement side and a disengagement side. A transmission device for an electric screwdriver that is equipped with a slide-operated feed mechanism and an operating piece outside the driver that operates the feed mechanism. 2. The transmission device for an electric screwdriver according to claim 1, wherein the feed mechanism is configured to automatically slide the slide gear to the disengaged side based on a high load being applied to the driver. 3. The transmission device for an electric screwdriver according to claim 1, further comprising a locking mechanism for fixing the external operation piece to a sliding position between a high-speed transmission output side and a low-speed transmission output side.