JP2501142Y2 - Electric tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electric power tool, and more particularly to an electric power tool capable of changing the rotational speed of the tool.

[Conventional technology]

Generally, inside the tool body, a drive motor that drives a desired tool to rotate through a gear reduction mechanism consisting of planetary gear mechanisms arranged in multiple stages is arranged, and the tool motor is turned on and off. A power tool is often used which is provided with a trigger switch for performing an operation, and by operating the trigger switch, the tool is rotationally driven to perform desired machining.

In such an electric power tool, conventionally, there is one equipped with a speed change mechanism capable of switching the rotational speed of the output shaft of the gear reduction mechanism rotationally driven by the drive motor to a low speed or a high speed and transmitting the speed to the tool. is there.

An electric tool having such a speed change mechanism is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-209883 or Japanese Patent Application Laid-Open No. 62-224585.

The speed change mechanism includes a slide gear having an internal gear that meshes with a planetary gear of the planetary gear mechanism, the slide gear being movably arranged in a rotation axis direction. It is designed to be held in a rotatable state. In the conventional electric power tool, an arcuate swing member is connected to the slide gear, and the slide gear can be moved by swinging the swing member with a shift lever. . By operating the shift lever, two types of reduction ratios can be obtained by the difference between the rotation speed of the planetary gear when the rotation of the slide gear is stopped and the rotation speed of the planetary gear when the internal gear is rotatable. Therefore, the desired speed change can be performed.

[Problems to be solved by the device]

However, in the conventional power tool, the slide gear is moved by swinging the swinging member by the shift lever, and moreover, since the swinging member is formed in an arc shape, When the load is applied to the moving member or the like, the swinging member is expanded and deformed, so that the slide gear cannot be moved smoothly and the reliability of the gear shifting operation is significantly reduced. Had.

Moreover, since the gear shift lever, the swinging member, and the like are required, the number of parts is increased, the manufacturing is difficult, and the manufacturing cost is increased.

The present invention has been made in view of the above points, and provides a power tool that can smoothly move a slide gear to remarkably improve the reliability of a gear shifting operation and can be easily and inexpensively manufactured. The purpose is to do.

[Means for solving the problem]

To achieve the above object, the present invention provides a drive motor 2 for rotating a desired tool in a tool body 1 through a gear reduction mechanism having a multi-stage planetary gear mechanism. A slide gear that has internal teeth 27a meshed with the planetary gear 12, and is fixed and rotated at a predetermined moving position to switch the rotation speed of the output shaft of the gear reduction mechanism.
27 is movably arranged along the axial direction, and a slide lever 22 is integrally formed on the outer peripheral side of the slide gear 27 so as to be exposed to the outside from the small hole 36 of the tool body 1. A structure of an electric tool for moving the slide gear 27 by connecting the annular holding ring 21 having a spring property surrounding the outer periphery and capable of bending in the axial direction is adopted.

[Action]

According to the present invention, by operating the slide lever to move the annular holding ring, the slide gear is held at the fixed position or the rotating position and the desired gear shifting operation is performed. It is possible to reliably prevent deformation of the retaining ring when a load is applied, etc. As a result, the slide gear can be smoothly moved, and the reliability of the gear shifting operation can be significantly improved. Moreover, since the slide lever is formed integrally with the holding ring, the number of parts can be reduced, and the manufacturing can be performed easily and at low cost.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 6 (a) to (c) show an embodiment of an electric power tool according to the present invention, in which a drive motor 2 is arranged inside a pistol type tool main body 1. On the output end side (front side) of the drive motor 2 inside the tool body 1, a substantially cylindrical gear case 3 has a predetermined gap with respect to the inner surface of the tool body 1. It is arranged. Further, the output pinion 4 of the drive motor 2 is meshed with a plurality of planetary gears 5 constituting the first stage planetary reduction mechanism, and each of these planetary gears 5 is provided on one surface side of the planet holding plate 6. It is rotatably supported by a shaft 7 formed in a protruding manner. A sun gear 8 of a second stage planetary speed reduction mechanism is integrally formed on the other surface side of the planet holding plate 6, and each planet gear 5 is formed on the inner surface of the gear case 3. The internal gear 9 is meshed.

The second stage sun gear 8 has a plurality of planet gears rotatably supported by a shaft 11 of a second stage planet holding plate 10.
12 are meshed, and the outer peripheral portion of the planet holding plate 10 is
The outer teeth 10a are formed, and the sun gear 13 of the third stage planetary reduction mechanism is integrally formed on the other surface side of the planet holding plate 10.

Further, a plurality of planetary gears 14 are meshed with the sun gear 13 of the third stage, and an internal gear 15 in a stationary state by being in pressure contact with the gear case 3 is arranged outside each of the planetary gears 14. The internal gear 13 and the planetary gear 14 mesh with each other. Further, each of the planetary gears 14 has a shaft 17 fixed to a planet holding plate 16 as a rotation shaft, the planet holding plates 16 that are driven to rotate are connected by the shaft 17, and the inside of the planet holding plate 16 is The outer teeth 18a formed on the spindle shaft 18 are fixed by spline engagement. Further, a chuck 20 for mounting a desired tool is connected to the front end portion 18b of the spindle shaft 18. The planetary gear mechanism and the planet holding plate 16 in the first to third stages constitute a gear reduction mechanism for rotationally driving the tool.

Further, between the tool body 1 and the gear case 3, an annular holding ring 21 made of a material such as resin having a spring property is provided.
Is arranged so as to be movable in the axial direction.
A slide lever 22 exposed to the outside from a small hole 36 on the upper surface of the tool body 1 is integrally formed on the upper portion of 21 (FIGS. 6A to 6C). Further, as shown in FIGS. 1 and 4, the upper and lower edges of the slide lever 22 are
An engagement protrusion 23 is formed, and the tool body 1 is formed with an engagement recess 24 that receives the engagement protrusion 23 at a predetermined low speed position and high speed position. Further, a pair of guide pins 25 are formed on both sides of the holding ring 21 so as to project therefrom, and the pair of guide pins 25 extend in the axial direction formed on both sides of the gear case 3. Guide hole 26
And is inserted into the inside of the gear case 3.

Further, internal teeth 27a meshed with the planetary gear 12 are formed inside the gear case 3 at a position corresponding to an outer portion of the planetary gear 12 meshed with the second stage sun gear 8. The slide gear 27 is provided so as to be movable in the axial direction, and the guide pin 25 of the holding ring 21 is provided in the annular recess 27c formed over the entire circumference of the slide gear 27.
Are engaged with each other and the slide gear 27 is rotatable. Further, in the vicinity of the inner teeth 9 of the gear case 3, a locking protrusion is provided.
28 is formed, and on the outer periphery of the slide gear 27,
An engagement recess 29 is formed to be engaged with the locking projection 28. The holding ring 21 is moved in the axial direction by operating the slide lever 22 back and forth so that the engaging projection 23 engages with the engaging recess 24 of the tool body 1.
By this movement of the holding ring 21, the guide pin 25 engaged in the annular recess 27c of the slide gear 27 is moved to the gear case 3.
The slide gear 27 is moved along the guide hole 26. Then, by moving the slide gear 27 rearward, the slide gear 27
When the engagement recess 29 of 27 is engaged with the locking projection 28 of the gear case 3, the slide gear 27 is not rotated and is in a stationary state, and the planetary gear 12 is rotationally driven at a low speed ( (Fig. 2). On the other hand, the slide gear 27 moves forward,
The engagement between the engagement concave portion 29 of the slide gear 27 and the locking projection 28 is released, and the slide gear 27 becomes rotatable, and the inner teeth of the slide gear 27 and the outer teeth of the planet holding plate 10 are also rotated.
By engaging with 10a, the slide gear 27, the planet holding plate 10, and the sun gear 8 rotate integrally, and the planet gear 12 rotates at high speed (third).
Figure).

Further, as shown in FIG. 1, a switch main body 30 for controlling the motor 2 is housed below the drive motor 2 inside the tool main body 1, and a lower end portion of the tool main body 1 is provided. A battery 31 for supplying power to the drive motor 2 is detachably mounted.

In addition, the tool body 1 has an O
A trigger switch 32 for performing N and OFF operations is attached, and a forward / reverse rotation switching lever for switching the rotation direction of the motor 2 is provided above the trigger switch 32 of the tool body 1.
33 are provided. The forward / reverse rotation switching lever 33 is rotatable about a shaft support pin 34 at a substantially central portion thereof.
The operation protrusions 35 protruding from both sides of the tool body 1 are integrally formed. In this embodiment, when the person operating the tool body 1 holds the tool body 1 and presses the portion of the operation protrusion 35 forward with his / her finger, the forward / reverse rotation switching lever 33 is moved. By rotating the switch body 30, the forward / reverse rotation switching pin (not shown) of the switch body 30 can be operated.

Next, the operation of this embodiment will be described. First, when the tool is used by rotating at a low speed, as shown in FIG. 2, the slide lever 22 is operated to the left in FIG. 1 to engage with the engaging recess 24 at the low speed position of the tool body 1. By engaging the portion 23 and moving the slide gear 27, the engaging recess 29 of the slide gear 27 is engaged with the locking protrusion 28 of the gear case 3.
To hold the slide gear 27 in a non-rotating state.

In this state, the operator holds the tool main body 1, puts a finger on the trigger switch 32, and pulls the trigger switch 32 to turn on the switch main body 30, and a signal from the switch main body 30 The drive motor 2 is rotationally driven. Then, the rotational force of the drive motor 2 is decelerated and transmitted to the spindle shaft 18 via the output pinion 4, the planetary gears 5, 12, 14 and the sun gears 8, 13, etc., so that it is mounted on the chuck 20. The tool is rotated to perform the desired processing. At this time, since the slide gear 27 is fixed in the non-rotating state, the second stage planetary gear 12 is rotated while meshing with the internal teeth of the fixed slide gear 27, and the reduction ratio is reduced. Getting higher,
The spindle shaft 18 is rotationally driven at a low speed.

When the tool is used by rotating at high speed, as shown in FIG. 3, the slide lever 22 is operated to the right in FIG. 1 to engage the engaging recess 24 of the tool body 1 at the high speed position. By engaging the portion 23 and moving the slide gear 27, the locking recess 29 of the slide gear 27 is disengaged from the locking projection 28 of the gear case 3, and the internal teeth 27 of the slide gear 27 are released.
By engaging a with the outer teeth 10a of the planet holding plate 10, the slide gear 27, the planet holding plate 10 and the sun gear 8 are integrated,
The slide gear 27 is held in a rotatable state.

In this state, when the operator pulls the trigger switch 32, the drive motor 2 is rotationally driven, and the output pinion 4, the planetary gears 5, 12, 14, ..., The sun gears 8, 13 are rotated.
The spindle shaft 18 is rotationally driven via the above. At this time, since the slide gear 27 is rotatable, the slide gear 27 is rotated together with the planetary gear 12, the sun gear 8, and the planet holding plate 10 of the second stage, and the reduction ratio is lowered. The spindle shaft 18 is driven to rotate at a high speed, and the low speed rotation and the high speed rotation can be easily switched by operating the slide lever 22.

Further, as shown in FIG. 5, when the slide lever 22 is moved, the teeth of the slide gear 27 and the teeth of the planetary gear 12 may not mesh with each other, but the holding ring 21 has a spring property. Since it is formed of the material that has, when the teeth of the drive motor 2 are brought into contact with each other by the rotation of the drive motor 2, the elasticity of the holding ring 21 allows the teeth to be engaged with each other.

Further, the operator presses the portion of the operation protrusion 35 with his / her finger to rotate the forward / reverse rotation switching lever 33, thereby causing the switch body 30 to perform a forward / reverse switching operation, and the drive motor 2 The rotation direction of is changed.

Therefore, in this embodiment, since the holding ring 21 is formed in a ring shape and the holding ring 21 is moved in the axial direction to perform the gear shifting operation, the holding ring 21 and the like are not loaded. When applied, it is possible to reliably prevent the retaining ring 21 from being deformed in the radial direction and the circumferential direction. As a result, the slide gear 27 can be smoothly moved, and the reliability of the gear shifting operation is improved. It can be significantly increased. Moreover, the slide lever 22
Since it is formed integrally with the holding ring 21, the number of parts can be reduced, and the manufacturing can be performed easily and at low cost.

[Effect of device]

According to the present invention, since the annular holding ring surrounds the slide gear and the slide lever integrated with the holding ring is pushed in the axial direction of the slide gear, the holding ring has a radial direction and a circumferential direction. Therefore, the slide gear can be smoothly and accurately moved in the axial direction without being bent, and thus without falling off from the slide gear, and the reliability of the shifting operation can be remarkably enhanced. Further, even if the teeth of the slide gear and the teeth of other gears do not mesh with each other when the slide lever moves, the annular holding ring has spring properties and can bend in the sliding direction from the position of the slide lever. When the teeth are brought into contact with each other by the rotation, the both teeth can be smoothly meshed by the elastic force of the holding ring. Furthermore, since the slide lever is formed integrally with the retaining ring,
The number of parts can be reduced, and the effects such as easy and inexpensive manufacture can be obtained.

[Brief description of drawings]

1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of FIG. 1 at a low speed, and FIG. 3 is a partially enlarged sectional view of FIG. 1 at a high speed. Fig. 4, Fig. 4 is a cross-sectional view of Fig. 2,
FIG. 5 is an explanatory view showing the operation of the retaining ring, and FIGS. 6 (a), (b), and (c) are a front view, a plan view, and a partially sectional side view of the retaining ring, respectively. 1 ... Tool body, 2 ... Drive motor, 3 ... Gear case, 5,12,14,16 ... Planet gear, 8,13 ... Sun gear, 18 ...
… Spindle shaft, 21 …… Retaining ring, 22 …… Slide lever, 23 …… Engagement protrusion, 24 …… Engagement recess, 25 …… Guide pin, 26 …… Guide hole, 27 …… Slide gear, 28 ...... Locking protrusions, 29 …… Engaging recesses, 30 …… Switch body, 32 ……
Trigger switch, 33 ... Forward / reverse rotation switching lever.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-166971 (JP, A) JP 49-56276 (JP, A) JP 55-76241 (JP, A)

Claims (1)

(57) [Scope of utility model registration request] 1. A drive motor for rotatably driving a desired tool through a gear reduction mechanism having a multi-stage planetary gear mechanism is provided inside the tool body, and is engaged with a planetary gear of the planetary gear mechanism. A slide gear, which has teeth and is fixed and rotated at a predetermined moving position to switch the rotation speed of the output shaft of the gear reduction mechanism, is arranged movably in the axial direction. The slide lever is connected to the axially bendable annular holding ring surrounding the outer periphery of the slide gear integrally formed with a slide lever exposed to the outside from a small hole of the tool body. An electric tool characterized by moving gears.