JPS6176281A - Electric 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] (Technical field) The present invention relates to an electric screwdriver.

(Background Art) Conventionally, a large number of electric screwdrivers have been provided that use the rotational force of a motor to tighten screws, but these generally have the following drawbacks.

B. The bit rotates as soon as the switch is turned on, which is dangerous.

When working continuously, the switch may be left on, but in that case, the bit is rotating even when the bit and screw first come into contact, and there is a risk of crushing the head of the screw. There is a risk of

C. For electric screwdrivers without a clutch mechanism, it is necessary to tighten the switch handle every time you tighten the screws to prevent them from collapsing when you complete screw tightening.
Also, if you pick up the Km electric screwdriver to disconnect the bit and screw and tighten the screw without operating the switch handle, there is a risk of crushing the head of the screw because the bit is rotating in the same way as the mouth. be.

Second, when working with the switch on, the bit rotates even when the screw is not actually being tightened, which results in energy loss and is uneconomical. In particular, the problem with photoelectric electric screwdrivers is that the number of screws that can be tightened with a single charge is reduced, making them difficult to use.

(Object of the Invention) The present invention has been proposed in view of the above points, and its purpose is to provide an easy-to-use, safe and economical electric screwdriver by eliminating various drawbacks of the above-mentioned screwdrivers. There is a particular thing.

(Disclosure of invention) The present invention will be fully explained below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which i
h Handle, 2 is the main switch, and 3 is the motor.

A pinion 4 is fixed to the rotating shaft 3a of this motor 3,
The rotational driving force is transmitted to the output shaft 7 via the gears 5a, 5b and the shaft 6. A chuck 8 is attached to the tip of the output shaft 7, and this chuck 8 holds a bit (not shown).

Around the connecting portion between the output shaft 7 and the shaft 6, a cylindrical outer collar 9b, which is a deceleration block 9t, is arranged in a four-core manner.
The load detection section 10 is in contact with the rear end edge T/C. The load detection part 10 has a groove 1 formed in the upper edge thereof in the axial direction.
As shown in FIG. 1(B), a retaining protrusion 11a formed on the circular surface of the no-closing case 11 is engaged with this groove 10a. The load detection unit 10 is supported by a spring 13 between the partition wall 12 and can move slightly (1 to 2 m) in the axial direction while resisting the spring 13. At the same time, the load detecting section 10 connects the engagement protrusion 11a to the 9-jing case 11.
It is locked to prevent it from rotating.

Further, a pressing protrusion 10 is provided below the rear end of the load sensing portion IO.
b protrudes rearward, and the bit at the tip of the chuck 8 comes into contact with the head of the screw, causing the load detection unit 10 to move back slightly, and the pressing protrusion iob presses against the housing case 11.
This is to press the micro switch 14 inside. A vA portion collar 16 is disposed behind the chuck 8 and is movable in the axial direction by following the chuck 8 while resisting a spring 17.

Figure 12 shows the circuit configuration of the present invention, in which a power supply 15, a motor 3, a main switch 2 and a microswitch 14 are connected in series, and unless both switches 2 and 14 are ON, the motor 3 will not rotate, and if either one is OFF, the motor 3 will stop. In addition, the main switch 2 has an ON lock mechanism, so that the main switch 2 is kept pressed once and the ON state is maintained.
Further, if the main switch 2 is further pressed, it can be returned to the OFF state. Therefore, turn on main switch 2
Micro switch 14t-ON, O
It is possible to switch between rotating and stopping the bit during FF operation.

Next, the operation of the present invention will be explained with reference to the 31st metal. Below, assuming continuous work and tightening screws with the main switch 2kON locked, first, as shown in Figure 3 (
A) is a snap) 1111) Tip part is fully screwed 19. head 19
It shows a state in which it is in contact with a. In this state, since the pressing force is not acting on the fixed member 20K, the load detection unit 10 and the deceleration block 9 are located below F due to the restoring force of the spring 13, and the microswitch 14 via the suppressing protrusion 10b7 is in the OFF state. Therefore, motor 3
When the bit 18 is at rest, the groove in the head 19a of the screw 19 can be picked up by cutting the bit 18 in a stationary state.

Next, when a pressing force is applied in the direction of the fixed member 20, the screw 19, bit 1B and chuck 8 are
The reaction force from 0 is transmitted to the load detection unit 10 via the head collar 16 and the deceleration block 9ft, and the load detection unit 10 is moved upwardly against the spring 13 as shown in FIG. Then, the microswitch 14 is pressed by the protrusion 10b, and the motor 3 rotates and the screw 19 is tightened via the bit 18.Furthermore, after the screw tightening work is completed, , when the main body is slightly lifted as shown in Fig. 3 (c), the reaction force of the fixed member 20 disappears, and the restoring force of the spring 13 is used to move the load detection part 10 and deceleration block 9 downward. As a result, the microswitch 14 is turned off again, and the motor 3 is stopped.

In this way, in the present invention, the main switch 2 is turned on.
The motor 3 can be driven only during the operation of actually tightening the screw 19 while remaining in the locked state at 7''c.

(Effects of the Invention) As described above, according to the present invention, when a pressing force is applied to the head of the screw through the bit l that rotates as a result of the motor,
The main switch is configured so that the reaction force acting in the wheel direction of the front gc bit drives the machine V load detection section and turns on the switch connected in series to the motor together with the main switch that can be locked ON. Even if the bit is inserted, it is safe because it will not rotate until it comes into contact with A and J.

The mouth and bit do not rotate until they come into contact with the screw, and the bit makes sure to pick up the groove in the screw head before tightening the screw, so there is no chance of crushing the screw head and causing damage.

C. Since the motor rotates only while the screw tightening work is actually being performed, there is no energy loss and it is economical. This means that the number of screws to be tightened per photoelectric recess increases, especially in the case of a rechargeable type, which has the advantage of being efficient.

2. If you use the main switch with the all-on lock,
It is very convenient to use and allows you to tighten the screw by simply pressing the bit onto the head of the screw without having to operate the handle of the main switch each time.

It has the following effects.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention.
A) is an explanatory diagram of the circular structure, and the same (B)) is A- of the same (A).
AvIr surface diagram, Figure 2 is a circuit diagram, Figure 3 (a) ~ (
C) is a diagram explaining the operation. 2...Main switch, 3...Motor, lO...Load 11L detection section, Work 4...
Micro switch, 18... bit, 19.
...Screw, 19a...Head figure 3 (c)

Claims (1)

[Claims] When a pressing force is applied to the head of a screw through a bit that rotates as a result of a motor, the reaction force acting in the axial direction of the bit drives the load detection section, and the main switch, which can be locked ON, is activated. An electric screwdriver characterized by being configured to turn on a switch connected in series to a motor.