JPH01257572A - Electric driver - Google Patents

Abstract

PURPOSE:To manufacture a push-start electric driven and a lever-start electric driver at a low coat and easily by constructing both drivers in the same manner. CONSTITUTION:A push-start electric driver where a driven shaft is reciprocated by tool pressing force to turn on a starting switch 19 and a lever-start electric driver where a starting switch is turned on by a lever are constructed in the same manner except a difference that while a lever is provided in the latter, a push-start switch rod 18 is provided in the former. Accordingly, the push-start electric driver and the lever-start electric driver different in a starting method can be manufactured only by replacing a switch rod with a lever.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a push start type electric screwdriver and a lever start type electric screwdriver.

[Background of the invention]

Conventionally, there are push-start type electric screwdrivers that use tool pressing force to activate the starting switch, and lever-start type electric screwdrivers that activate the starting switch using a lever.
The configuration has to be changed due to the difference in the starting method, which reduces the number of common parts, increases the cost of parts, and increases manufacturing costs both in terms of assembly and parts management.

[Purpose of the invention]

The purpose of the present invention is to provide a push start type electric screwdriver and a lever type electric screwdriver with almost the same configuration.
As a manufacturer, our objective is to provide an electric screwdriver that is easy to manufacture and inexpensive.

[Summary of the invention]

A feature of the present invention is that a button-type electric screwdriver and a lever-type electric screwdriver, which have different starting methods, are easily manufactured by changing the switch rod and lever to minimize the difference in structure.

[Embodiments of the invention]

The present invention will be explained in detail below using the embodiments shown in FIGS. 1 to 4.

FIG. 1 is a partial longitudinal sectional view showing an embodiment of the bush type electric screwdriver of the present invention, showing the rest state or the screw tightened state, in which the fixed clutch 3 and the steel balls 4, which are part of the movable clutch, are engaged. It shows the state of FIG. 2 is an overall view of the bush type electric screwdriver. FIG. 3 is a partial longitudinal sectional view of the lever type electric screwdriver, and FIG. 4 is an overall view of the lever type electric screwdriver. In FIG. 1, 1 is a motor, 2 is a speed reduction device using a planetary gear mechanism, and 3 is a fixed clutch that supports planetary teeth and a planetary gear 2a of a wheel mechanism 2. Note that the fixed clutch 3 holds the needle 3a and forms a cam surface. A steel ball 4 is placed in the hole 5a of the holding plate 6.
The sleeve 9. The rod 7 is press-fitted to the fixed clutch 3 via the movable clutch 5 and engages with the fixed clutch 3 to form a movable cam surface. In addition, a socket 14 for holding a driver bit (not shown) is connected and supported at one end of the shaft] 7 by a pin 15, and a key 12 is connected to the other end of the shaft.
A holding plate 6 is attached to the shaft 17 and rotates together with the shaft 17. The shaft 17 is capable of reciprocating in the axial direction, and when attached to the groove 17b compresses the spring 11 with a retaining ring. Numeral 13 is a gear cover housing the above-mentioned parts, and numeral 10 is a push-button limit switch fixed to the gear cover 13, which is turned on and off by a sleeve 9.

Next, the operation of each part during tightening work will be explained. When a driver bit (not shown) is pressed against a screw (not shown), the pressing force is applied via the bit, socket 14, shaft 17, and switch rod 18, and when the start switch 19 is turned on and the motor 1 is rotated, the rotation speed is increased. The speed is reduced by the planetary gear mechanism 2 and transmitted to the driver bit through the retaining plate 6, shaft 17, and socket 14 by the engagement between the needle 3a of the fixed clutch 3 and the steel ball 4, and tightens the screw.

As the screw continues to be tightened and reaches a tightening force determined by the pressing force of the torque adjustment spring 16, the friction angle between the needle 3a and the steel ball 4, the amount of engagement, and the radius of rotation, the steel ball 4 will tighten the needle 3.
When the spring 16 is compressed on the needle 3a and the movable clutch 5 is pushed out by the steel ball 4, the sleeve 9 is pushed out via the rod 7, and the limit switch 10 is activated. It operates and cuts off the power supply to the motor. On the other hand, the groove 17 of the shaft 17
Although the spring 11 is compressed via the retaining ring 8 attached to b, when the tool pressing force during tightening disappears after the tightening operation is completed, the shaft is pushed back by the recovery force of the spring 11 and the next tightening is started. have

FIG. 3 is a longitudinal sectional view of a lever-type electric screwdriver in which a retaining ring 8 is attached to the groove 17a of the shaft 17 to prevent the shaft 17 from reciprocating in the axial direction. In addition, the switch rod 18 shown in FIG. 1 is removed, and the lever spacer 21 is also removed, and the lever 22 and spring 23 are attached.

〔Effect of the invention〕

According to the present invention described above, it is possible to switch between a bush type electric screwdriver and a lever type electric screwdriver by simply changing a few parts, which has the advantage of ease of manufacture.

[Brief explanation of the drawing]

Figures 1 to 4 show embodiments of the present invention, respectively. Figure 1 is a vertical sectional view of the main part of a bush type electric screwdriver, Figure 2 is a side view of the whole, and Figure 3 is a lever type electric screwdriver. FIG. 4 is a vertical cross-sectional view of the main part of the driver, and FIG. 4 is a side view of the entire same. 1 is a motor, 8 is a retaining ring, 17 is a shaft, 17a is a groove, 17b is a groove, 18 is a switch rod, 19 is a starting switch, 21 is a lever spacer, 22 is a lever, and 23 is a spring. Patent applicant name Hitachi Koki Co., Ltd.

Claims (1)

[Claims] a dog clutch that interrupts output transmission between the drive shaft and the driven shaft of the motor when a predetermined load is applied; In the electric screwdriver, the electric screwdriver is equipped with a limit switch that is activated by a limit switch, and a switching circuit that cuts off power to the motor in response to a signal generated from the limit switch, and when the starting switch is turned on, the driven shaft is reciprocated by a tool pressing force. This electric screwdriver is characterized by having the same configuration as a push-start type electric screwdriver that uses a lever to turn on the start switch and a lever-start type electric screwdriver that uses a lever to turn on the starting switch, with the only difference being the presence or absence of a lever and the presence or absence of a push-start type switch rod. driver.