JPS6322277A - Power driver - Google Patents

Abstract

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

Description

[Detailed description of the invention] 【Technical field】

The present invention relates to an electric screwdriver, and particularly to an electric screwdriver configured so that it can be used as a manual screwdriver by locking the output shaft.

[Background technology]

To be able to use an electric screwdriver manually, a mechanism is required to lock the output shaft. In this case, there are two types: one in which the locking operation is performed manually and one in which the locking is performed automatically when the motor is stopped, as shown in Japanese Patent Application Laid-Open No. 58-217274. provided. However, in the former case, both the locking operation and unlocking operation must be performed manually, which makes the operation complicated, and sometimes causes the motor to be driven with the output shaft locked, resulting in motor lock. There is a possibility that In the latter case, the lock is automatically released and locked in conjunction with the rotation and stop of the motor, so there is no problem as described above, but conventional automatic locking mechanisms of this type are Since the system utilized the characteristics of the planetary gear mechanism, this automatic locking fi structure cannot be adopted in a device that does not use a planet + PLVT as a reduction part, and it is not possible to adopt this automatic locking fi mechanism. for,
The end part is inevitably complicated, and there are many problems not only in terms of assembly but also in terms of cost.6

[Purpose of the invention]

The present invention has been made in view of these points, and its purpose is to provide an electric screwdriver that is easy to use due to its automatic locking mechanism, has a simple structure, and can be provided at low cost. It is on offer.

[Disclosure of the invention]

Accordingly, the present invention provides a locking member that engages with and locks the output portion rotationally driven by the motor, and also includes an interlocking control member that controls the movement of the locking member in conjunction with the motor power switch. A feature of the present invention is that the output section is locked and unlocked in accordance with the operation of the motor power switch. This interlocking control member includes a tI11 mechanical mechanism, such as a link that connects the operating handle of the motor power switch and the lock member, whose spring biases the lock member as the motor power switch is turned on and off. The present invention will be described in detail based on the illustrated embodiment. FIGS. 1 to 3 show one embodiment, and the pistol-shaped appearance is shown in FIGS. This electric screwdriver has a gearbox 7 housed in the tip of its housing 1, which includes a speed reduction unit 10 configured with a planetary mechanism.
An output shaft 2 is connected to a motor (not shown) through a bearing 11, and is supported by a bearing 11. The output shaft 2 protrudes from the front end surface of the housing song 1, and a screwdriver bit is attached to the tip of the output shaft 2. A chuck 8 is attached. , the output shaft 2 here is as clear from FIG.
The rear end disc portion 21 on the deceleration portion 10 side is connected to the deceleration portion 1
This disk portion 21, which functions as a planetary carrier to support the planetary gear 15 at 0, and which also serves as a member of the deceleration portion 10, is provided with meshing teeth 22 on the outer peripheral surface thereof. The output shaft 2 is located at the tip of the space inside the gearbox 7.
A mouth that can freely slide in the axial direction? A locking plate 3 is disposed on the outer periphery of the locking plate 3, and meshing teeth 32 as internal teeth that can freely mesh with the meshing teeth 22 of the disc portion 21 are provided on the outer periphery of the locking plate 3. A coupling 7-m 31 is formed which exits the gearbox 7 through a long groove 17 formed in the housing 1 and extends to the rear of the housing 1. Then, by which engagement of the long groove 17,
The rear end of this connecting arm 31, which restricts rotation of the lock plate 3 with respect to the gear box 7, is connected to one end of a link 4 whose central portion is pivotally supported on the housing 1 by a pongee 40. On the other hand, it is provided with a protrusion 50 for driving the power switch SW for the motor, and a return spring 52 in the return direction.
Attached by! ! The switch handle 5, which has a length of 8L, is provided with a connecting piece 51 that protrudes forward and is connected to the end of the link 4 at the tip thereof, and is slidable in the front-rear direction of the housing 1. When the switch handle 5 is operated, the lock plate 3 slides in the opposite direction to the switch handle 5 via the link 4. That is, when the switch handle 5 is not operated and the power switch SW is turned off, the engagement 1!132 of the lock plate 3 is caused by the disc portion of the output shaft 2, as shown in FIG. By engaging with the interlocking teeth 22 at 21,
Output MI2 is locked, so it can be used as a manual screwdriver. From this state, pull the switch handle 5 to turn on the power switch SW and energize the motor.
As shown in the figure, the lock plate 3 moves forward in conjunction with the operation of the switch handle 5 and is disengaged from the output shaft 2, so the output shaft 2 is rotationally driven by the motor output. Ru. When the switch handle 5 is released, as the switch handle 5 is returned by the return spring 52, the lock plate 3 also returns and re-engages with the output shaft 2, thereby locking the output shaft 2. Automatic locking and automatic unlocking are performed mechanically in conjunction with the operation of the switch handle 5 for the motor power switch SW. Other embodiments are shown in FIGS. 4 and 5. gear box 7
The lock plate 3 is slidably and non-rotatably provided in the tip of the gearbox 7, and the lock plate 3 is provided with meshing teeth 32 for engaging which output shaft 2. An electromagnet 6 is installed on the tip surface of the housing 1, and a return spring 33 made of a compressed fill spring has a locking plate 3 made of a magnetic material placed inside the tip of the housing 1, and a return spring 33 is used to move the output shaft 2 backward, that is, to engage the output shaft 2. This embodiment differs from the above embodiment in that it is biased by a spring in the direction. As is clear from FIG. 5, the electromagnet 6 is connected to the motor M
When the motor power switch SW is turned on, it is connected to the power supply B together with the motor M. When the power switch SW is turned off, the lock plate 3 engages and locks the output shaft 2 under the force of the return spring 33, but when the power switch SW is turned on, the electromagnet 6 sucks the lock plate 3 and moves it forward, and in order to disengage the lock plate 3 from the output shaft 2, the output shaft 2
is unlocked, and the output shaft 2 is rotationally driven by the motor M. FIG. 4 shows this state when the lock is released. S in FIG. 5 is a switch for changing the rotational direction of the motor M, and 9 in FIG. 3 is an operating handle for this switch S. In any of the embodiments, it is preferable to add a brake mechanism to stop the inertial rotation of the output shaft 2 when the power to the motor is cut off. This is because the lock plate 3 and the output shaft 2 can be re-engaged smoothly.

【Effect of the invention】

As described above, in the present invention, the output section is locked and unlocked in accordance with the operation of the motor power switch.Therefore, it is not only easy to use, but also locks the output section. Since the operation of the lock plate and the operation of the power switch are linked by an interlock control member, there is no need for a complicated mechanism like the conventional example that utilizes the characteristics of a planetary mechanism, and there is no need for a link etc. It can be easily configured with mechanical coupling means or electromagnetic coupling means such as electromagnets, and can be provided at low cost.
It can be provided with good assemblability.

[Brief explanation of the drawing]

FIG. 1 and tJS2 are cutaway side views of one embodiment of the present invention.
FIG. 3 is a perspective view of the same as above, FIG. 4 is a cutaway side view of another embodiment, and FIG. 15 is a circuit diagram of the same as above, in which 1 is a housing;
2 is an output shaft as an output part, 3 is a lock plate, 4 is a link, 5 is a switch handle, 6 is an electromagnet, 33 is a return spring, M is a motor, and SW is a power switch for the motor. Agent Patent Attorney Ishi 1) Chief Figure 7 3

Claims (3)

[Claims] (1) A locking member is provided that engages with and locks the output portion rotationally driven by the motor, and an interlocking control member is provided that controls the movement of the locking member in conjunction with the motor power switch. An electric screwdriver characterized by: (2) The electric screwdriver according to claim 1, wherein the interlocking control member is a link connecting the operating handle of the motor power switch and the locking member. (3) The electric screwdriver according to claim 1, wherein the connection control member is an electromagnet that drives the lock member against its spring bias as the motor power switch is turned on and off.