JPS59232773A - Motor tool - 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 [Technical Field 1] The present invention relates to power tools, particularly power tools such as electric screwdrivers and electric drills.

1 BACKGROUND TECHNOLOGY] In the power tool as described above, it is desirable from the point of view of workability that the number of revolutions of the chunk to which the driver bit or drill bit is mounted is variable.

A conventional example that takes this point into consideration is shown in Figure 1-5.
5: For the motor 3 and the chuck; The chuck 8 is designed to be coaxial with the chuck 8, and a Ni
A battery pack 2 of -Cd storage batteries is installed. To explain the power transmission system including the planetary mechanism in more detail,
The first stage planet (sun gear 4 in the structure) is fixed to the output shaft of the motor 3, which is disposed through the motor holder 12 in the main housing 1.
The stand 12 has a dimension of 1 inch for the cylindrical gear case 11. A single internal gear 6 is freely rotatably housed in the gear case 11, and a plurality of planetary gears 5 are supported within the internal gear 6 by a carrier 7 and mesh with the sun gear 4. Sun gear 1 in the second stage planetary mechanism installed on carrier 7
4. A plurality of planetary gears 15 are housed, supported by a carrier 17 integrated with an output shaft 18 having a chuck 8 at its tip and meshing with the sun gear 14. Note that both the planetary gear 5 and the planetary gear 15 mesh with the internal gear 6. As is clear from FIG. 3, the tip surface of the internal gear 6 has a large number of radially formed protrusions 36, and a steel ball held in the gear case 11 is attached to the tip surface. 37 or close. Attach it to the tip of the main body housing l (J plate 34
Between the adjustment tube 30, which is rotatable within a certain range according to the above, and the tip surface of the gear case 11, there is a washer 33 in contact with the ball 37, and a rotation of the adjustment tube 30. An adjustment plate 31 that moves back and forth with the adjustment plate 31 and a spring 32 located between the two are disposed. The ball 37 is brought into pressure contact with the tip end surface of the internal gear 6 by the spring 32. In other words, normally the engagement between the ball 37 and the protrusion 36 of the internal gear (3)
The rotation of the internal gear 6 is blocked 1), so the rotation of the motor 3 is decelerated by the two-stage planetary mechanism and transmitted to the output shaft IS and the chunk 8. However, if the load torque exceeds a predetermined value, the internal It constitutes a torque limiter that prevents the output shaft 18 from rotating when the Rugiaro starts idling, and the starting torque is adjusted.
It is made variable by adjusting the amount of compression of the spring 32 by the rotation of the spring 30. In the diagram, 19°20.21 is a washer.
22 is a thrust bearing, and 23 is a stop ring attached to the output shaft 18.

Now, the variable configuration due to the rotation of the chuck 8 in this device is achieved by changing the voltage applied to the motor 3 by switching the batteries V of the battery pack 2 between series and parallel. That is, in FIG. 2, 70 is a movable contact plate that is moved by the switch handle 10 to change the connection between the three terminals 71. In the position marked ■ in the figure, it is connected in series for high-speed simultaneous rotation, and in the position marked ■, it is connected in series for low-speed rotation. In parallel, the position of ・■ is neutral. Reference numeral 72 is a movable contact plate for switching between normal rotation and reverse rotation, and the position i is for normal rotation, and the position 11 is for reverse rotation.

In this electric motor 7 configured as described above, the reduction gear has two stages of play length (one structure), so the power transmission system from the motor 3 to the chuck 8 is compact. Therefore, it is small overall.

However, the following problems exist. That is, originally, high-speed rotation is suitable for light loads, and 1 degree rotation is suitable for heavy loads. However, the rotation speed is changed by changing the voltage applied to the motor 3, and the force and voltage at high speed rotation are high. Here, considering the characteristics of the motor 3 and considering that it is a battery \i or a N1cdW battery, the maximum load torque is larger when the applied voltage is high than when it is low, and the low speed rotation high torque 1' In addition, with regard to the batteries, there is a possibility that problems such as inter-battery discharging and overcharging may occur due to capacity imbalance between the batteries N7 when used in parallel and single.

Of course, if the speed change is made variable by incorporating a gear shifter, the above problems will not occur, but conventionally, the gearbox in this case has gears as shown in Figure 4. Binion 24 with two different numbers of teeth and a different number of teeth - Moon's teeth lj 'l 5
Since a conventional motor was used, it was inevitably large due to the large capacity of the transmission part, and in addition, locating the motor 3 and chuck 8 at the axis of the main housing 1 made it difficult to work. Therefore, it is preferable that the axes of the motor 3 and the chuck 8 are coincident with each other, but such an arrangement can be used without increasing the number of gears.

1 Objective of the Invention 1 The present invention has been developed in view of the above points, and aims to be small and easy to use, and also to be able to switch the rotation of the chuck between high and low speeds, and to rotate the chuck at low speeds. To provide a power tool that can handle heavy loads.

[Disclosure of the Invention] The present invention provides a sun gear and an internal gear provided on the output shaft of the motor, between the motor and the chuck output shaft provided coaxially with the output shaft of the motor. In a power tool equipped with a speed reducer configured with a planetary mechanism consisting of a planetary gear that meshes with an internal gear and a sun gear, and a carrier that is connected to an output shaft to the chuck and supports the M star gear, is formed by a first gear and a second gear that have different numbers of teeth and rotate as one, and the internal gear is formed with a first internal gear that has a different number of teeth and is rotatable separately from each other. and a second internal gear, and the rotation of the first internal gear that meshes with the first gear and the second internal gear that meshes with the second gear is selectively controlled by a switching lever. The reduction ratio can be changed depending on which of the first and second internal gears is stopped from rotating.

1;), the present invention will be explained in detail based on the illustrated embodiments shown in FIG. 5 and below. This power tool is the Rmi version T+'77
The structure is the same as that shown in Fig. 1, and the motor 3 is coaxially arranged inside the pistol-shaped Honjo housing 1.
A speed reducer is provided between the chuck 8 and the chuck 8, and a torque limiter is formed using a 2-Jul tl planetary structure.

However, unlike the conventional example, the internal gears in the planetary mechanism of 2 Fffi EJ and the first stage planetary mechanism are not shared; In the first stage planetary mechanism, the internal gear 6 is composed of two separately rotatable first internal gears 61 and second internal gears 62 arranged in the axial direction, and the planetary gears 5 are also sun gears. 4, the first gear 51 meshes with the first internal gear 61, and the first gear 51 meshes with the second internal gear 62.
It consists of a gear 51 and eleven second gears 52. The first internal gear 61 and the second internal gear 62 are assumed to have different numbers of teeth, and the first gear 51 and the second gear 52 are also assumed to have different numbers of teeth. In the illustrated embodiment, the first gear 51 has more teeth than the second gear 52, and the first internal gear 61 has more teeth than the second internal gear 62. Both the first internal gear 61 and the second internal gear 62 are rotatably supported by the inner surface of the gear case 11. A large number of engagement grooves 4 are formed on the outer peripheral surface of each end at intervals of one inch in the circumferential direction.
1.42 is provided. A through hole 43 is formed in the gear case 11 at a position corresponding to both the engaging grooves 41 and 42.

When the motor 3 is rotated, if both the first internal gear 61 and the second internal gear 62 are in a rotatable state, the rotation of the first internal gear 61 and the second internal gear 62 causes the motor to idle, and the chuck However, the rotation of these parts can be selectively stopped by a switching lever 9. , - switching lever 9 is disposed between the inner surface of the wooden housing 1 and the gear case 11 so as to be slidable in the axial direction of the wooden housing 1, and when retracting, the engaging protrusion 45 at one end is moved to the XO position 1t. One through hole 43 as shown here
through the engagement groove 41 of the first internal gear 61, i
; When advancing i (this is the engagement groove 42 of the second internal gear 62)
This engagement causes the first internal gear 61 to
The shaft is for preventing the rotation of the second internal gear 2. The switching lever ≦J is operated by a switch handle 10 for controlling the motor 3. That is, the switch handle 10
An arm 55 is extended further forward, a recess 56 is formed at the tip of the arm 55, and a switching lever 9 is inserted into the fourth part 55.
The receiver protruding from the rear end positions the piece 47, and
The receiver has compression springs 5 between the piece 47 and the front and rear walls of the four parts 55, respectively.
7.58 is placed. Further, the tip of the switching lever 9 is provided with a click engagement 46 that clicks into engagement with a retaining rib 44 provided on the outer surface of the gear case 11.

Now, when the switch handle 10 is not pulled, the first
As shown in FIG. 1(a), the switching lever 9 is in a state of being pushed forward by the compression spring 58, and the engaging protrusion 4
5 is engaged with the engagement groove 42 of the second internal gear 62. When the switch handle 10 is pulled out one step from this state, as shown in FIG. maintain a state in which rotation is prevented. On the other hand, by pulling the switch handle 10, the motor 3 is activated and rotates the sun gear 4.

Planetary gear 5 that meshes with sun gear 4 and first gear 51
The system rotates at a speed determined by the meshing of the second gear 52 and the second internal gear 62 while causing the @1 internal gear 61 to idle, and applies power to the subsequent members.
reach it. If the switch handle 10 is further pulled, at this time, as shown in FIG. Since the first internal gear 61 is prevented from rotating by engaging with the engagement groove 11, the rotation of the motor 3 is transmitted to the output shaft 18 while causing the second internal gear 62 to idle.

Next, the reduction ratio in both of the above states will be described.

Now, the number of teeth of sun gear 4 is ZA, and the number of teeth of planetary gear 5 is 5.
1, the number of teeth of the second gear 52 is χ1-1, the number of teeth of the first internal gear 61 is ZD, the number of teeth of the second internal gear 62 is ZE, the number of teeth of the sun gear 14 is ZF, @ The number of teeth of the star gear 15 is Zc, the number of teeth of the internal gear 16 is Z14, and the number of rotations of the output shaft of the motor 3 is N.
In the state in which the rotation of the first internal gear 61 is prevented as shown in FIG. When the rotational speed of the output shaft 18 is N2, that is, the state shown in FIG. 9 has a larger reduction ratio, resulting in a low speed, high torque output, and the state shown in FIG. 10, a high speed and low torque output. If the power tool here is one that can be used for drilling holes as an electric drill and tightening screws as an electric screwdriver, the number of revolutions required for screw tightening,
The preferred ratio to the number of rotations required for drilling is 1.5 to 2.
．． It's about 5.

, :If you find a condition where the nol rate is 2, it becomes like a dog.

However, the teeth of the sun gear 4, the planetary gear 5, the first internal gear 61, and the second internal gear 62 are the same, and the axes of the first gear 51 and the second gear 52 are the same, and ZA+2ZB:ZDI ZA+ZB+ZC =ZE.

KI:1st-Z-H-7B j ZA ZcN2
]+7. U, l/ZA=”B+Zc−Z,+1=
2 2Zc 2Zo 2 ,', Z8=32° [Advantage of the invention 1 As described above, in the present invention, since the reduction gear made of the planet ft1tfff is used, it is small and the motor and chuck are the same. It is easy to use as a shaft core, and because the reduction ratio can be switched, it is possible to use high speed rotation low torque output and substitute speed rotation high torque output for one purpose. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a broken front view of the conventional example, Fig. 2 is a circuit diagram of the same 1-, fjS: (The figure is an exploded perspective view of the same as above, and Fig. 1 is a broken front view of the conventional example of Ike. 5 is a perspective view of an embodiment of the present invention, FIG. 6 is a cutaway front view of the same, FIG. 7 is a circuit diagram of the same, FIG. 8 is an exploded perspective view of the same, and FIGS.
The figure is a cross-sectional view of the same as above, and FIGS. 11(a) (+3) and (c) are cross-sectional views explaining the switching operation of the same as above, 1 is the main body housing, 3 is the motor, 4 is the sun gear, and 5 is the planetary gear. ,
6 is internal gear, 7 is carrier, 8 is chuck,
9 is a switching lever, 10 (soil switch handle, 51
indicates fjS1 gear, 52 (Toshio 2 gear, 61 indicates 1st internal gear, and 62 indicates 2nd internal gear. Agent: Patent Attorney Ishi 1) Chief 7th Procedural Amendment (Method) October 1981 7t ] 1988 Patent Application No. 1 (1G 888 No. 2, Name of Invention Power Tool 3, Relationship with the Amendment Person Case Patent Applicant Address 1048 Oaza Kadoma, Kadoma City, Osaka Prefecture Name (583) Matsushita Electric Company) Representative of two joint stock companies
Iku Kobayashi 4, agent postal code 530 5, date of amendment order September 7, 1981

Claims (2)

[Claims] (1) Between the motor and the output shaft to the chuck provided coaxially with the output shaft of the motor, a sun gear provided on the output shaft of the motor, an internal gear, and a planet meshing with the internal gear and the sun gear. There is only one planetary gear (an electric motor equipped with a reduction gear consisting of an alternative structure) consisting of a gear and a carrier that is connected to the output shaft to the chuck and supports the planetary gear, and the number of the planetary gears is the same. The internal gear is formed by a first gear and a second gear that are different in number of teeth and rotate at -IG, and the internal gear has a first internal gear and a second internal gear that have different numbers of teeth and are rotatable independently of each other. A power tool comprising: a first internal gear that meshes with the first gear; and a second internal gear that meshes with the second gear; rotation thereof is selectively controlled by a switching lever. (2) The electric motor according to claim 1, wherein the switching lever controls the rotation of the first internal gear and the second internal gear in response to a switch handle for controlling the motor] 1 soldier.