JP2000006041A - Torque keeper for electric driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque keeper for electric driver which can set a necessary set torque freely fitting to the terminal screws of several positions of a watthour meter and the like, and can improve the working efficiency. SOLUTION: A housing main body 43 is formed by screwing and fitting a tool side main body 1 and a bit side main body 37, a bit holder 23 to install a bit 24, and a torque limiter 7 are installed in the housing main body 43, and a connection shaft 3 installed to a shaft holder at the front end of an electric driver D is connected to the shaft holder through the torque limiter 7, so as to compose the torque keeper. The necessary set torque value of the torque limiter 7 is made possible to be set freely by fastening the screws of the tool side main body 1 and the bit side main body 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque keeper for an electric screwdriver which is detachably mounted on a commercially available electric screwdriver and used for screwing work.

[0002]

2. Description of the Related Art Conventionally, a commercially available electric screwdriver has a base end of a bit fitted to a shaft holder provided at a distal end of an operating portion, and a torque setting mechanism provided on the electric screwdriver. Although the value is set and used, since the pitch interval of the torque setting value in the torque setting mechanism is relatively large, it often does not match the required torque suitable for the screw to be fastened. Therefore, for example, when tightening the terminal screw of the watt-hour meter, the torque value is set at a value lower than the required torque value by the torque setting mechanism of the electric screwdriver.First, after the terminal screw is tightened by the electric screwdriver, The screwing operation has been performed either by re-tightening with a manual torque screwdriver adjusted to a preset torque value or by tightening with a manual torque screwdriver from the beginning without using an electric screwdriver.

[0003]

However, in such a conventional method, in the former case, the use of both the electric driver and the manual torque driver is troublesome and troublesome, and the latter manual operation is troublesome. In the case where only a torque driver is used, there is a problem that the work efficiency is low in any case, for example, it takes a long time to tighten and is troublesome.

Accordingly, the present invention has been made to solve such problems in the prior art, and is used by being detachably attached to a shaft holder of a commercially available electric screwdriver, thereby achieving a tightening torque value of the screw. It is an object of the present invention to provide a torque keeper for an electric screwdriver that can freely set a desired torque value according to the purpose and application.

[0005]

In order to achieve the above object, a torque keeper for an electric screwdriver according to the present invention forms a housing body by screwing a tool side body and a bit side body together. A bit holder and a torque limiter for fitting the base end of the bit in the housing main body are provided, and a connection shaft fitted to the shaft holder at the tip of the electric screwdriver is connected to the bit holder via the torque limiter. Be composed. Therefore, the screws of the tool-side main body and the bit-side main body are tightened in advance in accordance with the required set torque value of the screw, and the torque value of the torque limiter is set to a required value. Then, the connection shaft is fitted to the shaft holder at the tip of the electric screwdriver, the torque keeper is mounted, and each screw is tightened.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a torque keeper for an electric screwdriver according to the present invention will be described below with reference to the drawings. 1 is an external perspective view of the torque keeper, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a transverse sectional view thereof. In the drawing, reference numeral 1 denotes a hexagonal insertion hole 4 through which a connection shaft 3 whose main part has a hexagonal cross section is inserted through the center of the disk portion 2, and a short cylindrical peripheral side wall around the disk portion 2. 5 is a tool-side main body formed so as to protrude, and has an external thread portion 6 on the outer peripheral surface of the peripheral side wall 5.
Is engraved.

Reference numeral 7 denotes a torque limiter for transmitting the power from the connection shaft 3. In this embodiment, a lock fitting 8, a holding fitting 9, a ball holder 10,
A plurality of steel balls 13 are provided between the lock fitting 8 and the ball retainer 10 in combination with the disc springs 11 and 11 and the flat washers 12.
Is to be clamped.

The lock fitting 8 is provided with a shaft cylinder portion 15 through which the connection shaft 3 is inserted through the center of a disk portion 14.
Six lock holes 16 are formed concentrically at equal intervals on the surface of the disk portion 14 on the side where the shaft cylinder portion 15 protrudes, into which the steel balls 13 are shallowly fitted. The gripping metal 9 is used for the disk unit 1.
7, a shaft tube portion 18 is inserted from both sides of the lock tube 8 to allow the shaft tube portion 15 of the lock member 8 to pass through a small-diameter portion 26 on the base end side of the bit holder 23, which will be described later. Six holding holes 19 communicating with the lock holes 16 provided in the disk portion 14 and holding the steel balls 13 are provided concentrically. A pin insertion hole 20 and a pin insertion hole 20 are respectively formed in the cylindrical portion on the distal end side of the connection shaft 3 and the shaft cylinder portion 15 of the lock fitting 8.
The connection shaft 3 and the lock fitting 8 are integrally connected by driving the spring pin 22 with the pin insertion holes 20 and 21 communicating with each other. Ball holder 10, disc springs 11, 11 and flat washer 12
Are each formed in a ring shape, and are fitted to the shaft tube portion 18 of the gripping metal fitting 9.

Reference numeral 23 denotes a bit holder into which the bit 24 is fitted. The bit holder 23 is made of a plastic having impact resistance and high insulation to provide insulation. A blind hole 25 formed of a hexagonal hole for fitting the base end side of the bit 24 is provided at the distal end side, and a small-diameter part 26 is provided on the base end side to be inserted into the shaft cylindrical part 18 of the gripping metal 9. ing.
A pin insertion hole 27 is penetrated through the small diameter portion 26, and a spring pin 29 is driven in a state where the pin insertion hole 27 and the pin insertion hole 28 penetrated through the shaft cylinder portion 18 of the holding metal fitting 9 communicate with each other. . As a result, the bit holder 23 is
Are connected together.

The bit 24 has a base end portion 30 formed in a hexagonal cross section.
A coil spring 31 is wound around the bit 24 while being fitted in the blind hole 25, and then the bit cover 3 is
2 are deposited. The tip of the bit 24 has a blade 33 of one type.
Is formed, and yellow paint 34 is applied to both side surfaces of the blade portion 33 as shown by oblique lines in FIG. 4, and is color-coded so that the direction of the tip position of the blade portion 33 can be easily understood. Also,
The paint 34 is also applied to the inside of the vertical groove 35 along the axial direction on the side surface of the bit 24 to make it difficult to peel off. The bit cover 32 is for guiding the blade portion 33 so as not to come off from one groove of the screw when the screw is tightened by the blade portion 33 of the bit 24, and is provided on the outer peripheral surface at the base end of the cylindrical body. A flange 36 is provided around and is integrally formed of a transparent acrylic resin.

Reference numeral 37 denotes a bit-side main body. A large-diameter cylindrical portion 39 fitted to the peripheral side wall 5 of the tool-side main body 1 is integrally formed on the base end side of the small-diameter cylindrical portion 38 in which the bit holder 23 is provided. The female screw portions 40 and 41 are engraved on the inner peripheral surfaces of the distal end side of the small diameter cylindrical portion 38 and the base end side of the large diameter cylindrical portion 39, respectively. The large-diameter cylindrical portion 39 has three screw holes 42.
They are provided at equal intervals. Then, the bit-side main body 37 formed in this way is put on the bit 24 and the bit holder 23 on which the bit cover 32 is attached, and the female screw part 41 of the large-diameter cylindrical part 39 is screwed into the male screw part 6 of the tool-side main body 1. To fit. Thus, the tool side main body 1 is replaced with the bit side main body 3
7, the housing main body 43 is formed. At this time, the flat washer 12 is pressed by an abutting wall 37a formed at an intermediate portion inside the bit-side main body 37, and the disc spring 1 is pressed.
The set torque value can be set by compressing 1,1. In this set state, a set screw 44 with a hexagonal hole is screwed into each of the screw holes 42, and a part of the male screw portion 6 of the tool side main body 1 is crushed by the tip of the set screw 44 with a hexagonal hole. Can be locked to prevent loosening.

After the setting, the bit 24 is stopped, the connecting shaft 3 is further rotated, and when a force greater than the set torque value is applied to the torque limiter 7, it is fitted into each lock hole 16 with the rotation of the lock fitting 8. Each of the steel balls 13 moves to the next lock hole 16. At this time, a sound "click!" Is generated by each steel ball 13 and the lock fitting 8, and this sound can be recognized as a limiter sound.

A cap 45 is screwed onto the tip end of the bit-side main body 37. An external thread 46 is screwed into an internal thread 40 formed on the inner peripheral surface of the small-diameter cylindrical portion 38 of the bit-side main body 37 on the outer peripheral surface. And the cap 45 is attached to the bit side main body 3.
The female screw portion 40 and the male screw portion 46 are screwed together by fitting the small-diameter cylindrical portion 38 of FIG. In this state, the bit cover 32
When the flange portion 36 is abutted against the inner peripheral wall 47 at the distal end of the cap 45 and is pressed by the spring of the coil spring 31, the bit 24
Cover without getting out of. Reference numeral 48 denotes a heat-shrinkable tube for covering and protecting the outer peripheral surface of the housing body 43. Reference numeral 49 denotes a display tape wound around the outer peripheral surface of the housing main body 43, and a set torque value is displayed on the surface.

The torque keeper 50 according to the present invention has the above-described structure, and a method of using the same will now be described. The electric screwdriver D shown in FIG. 5 is a commercially available one, and is configured by connecting an operating part 52 to the tip of a grip part 51 in which a rechargeable battery is loaded so as to be able to bend and extend. The operating unit 52 is provided with a forward / reverse rotation changeover switch 53 and a lock switch 54 for locking the changeover switch 53 at the base end side, and a rotation speed changeover switch 55 at the center. Further, a clutch handle 57 having a scale 56 on the peripheral surface is provided on the distal end side.
And a fitting hole 58 of a shaft holder into which the connection shaft 3 of the torque keeper 50 is fitted at the center thereof.
Is provided. And the clutch handle 5
7 to the maximum scale 6 and the rotation speed switch 55
Is set to “LOW”, and the connection shaft 3 of the torque keeper 50 is connected to the electric screwdriver D as shown in FIG.
Into the fitting hole 58 until a click is heard. Then, the blade portion 33 of the bit 24 is fitted into one groove of a terminal screw of a terminal portion of a power meter (not shown),
The changeover switch 53 of the electric screwdriver D is pushed forward to rotate the bit 24, and the terminal screw is tightened until the limiter sound of the torque keeper 50 is continuously generated about five times. Finally, the tightening state of the terminal screws is confirmed to complete the operation. Hereinafter, the same operation is repeated to tighten the terminal screws.

If the bit 24 and the bit cover 32 are damaged during repeated use as described above, the cap 45 is screwed off from the bit-side main body 37 and removed, and the bit cover 32 is removed. And remove the bit 24 from the bit holder 23
And the bit 24 and / or the bit cover 3
After the conversion of 2, 2 is assembled in the reverse order.

[0016]

As described above, the torque keeper for an electric screwdriver according to the present invention allows the required torque value to be set freely according to the purpose or application according to the tightening force of the screw via the built-in torque limiter. By using such a torque keeper mounted on a commercially available electric screwdriver, it is possible to use both a conventional electric screwdriver and a manual torque screwdriver. This eliminates the problem that it takes time, as in the case of using only one, and has the effect of improving work efficiency. Furthermore, if the bit and the connection shaft are connected via an insulating bit holder, high insulation is maintained even in a hot wire state, and work can be performed safely. In addition, there is an effect that the completion of tightening of a required torque value can be easily recognized when the screw is tightened.

[Brief description of the drawings]

FIG. 1 is a perspective view of a torque keeper for an electric screwdriver according to the present invention.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a transverse sectional view of the same.

FIG. 4 is a side view of a bit.

FIG. 5 is an exploded perspective view of an electric screwdriver and a torque keeper.

FIG. 6 is a perspective view showing a state where a torque keeper is mounted on the electric screwdriver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool side main body 3 Connection shaft 6 Male thread part 7 Torque limiter 23 Bit holder 24 Bit 30 Base end part 37 Bit side main body 41 Male thread part 43 Housing main body 50 Torque keeper D Electric screwdriver

Continuation of the front page (72) Inventor Kouji Kajimoto 4-2-6 Sakuradai, Seki City, Gifu Prefecture

Claims (1)

[Claims] 1. A bit holder and a torque limiter for forming a housing main body by screwing and fitting a tool side main body and a bit side main body to each other, and fitting a base end portion of a bit into the housing main body. The connecting shaft fitted to the shaft holder at the tip of the electric screwdriver is connected to the bit holder via the torque limiter,
A torque keeper for an electric screwdriver, wherein a required set torque value of the torque limiter can be freely set by tightening screws of the tool side body and the bit side body.