JPS6156068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an attachment that is attached to the rotating shaft of an electric rotating tool when tightening a drill screw.

Drill screws have the excellent ability to simultaneously perform pilot hole cutting and screw tightening in one process, and due to their workability, they have recently come to be used in large quantities for fastening various metal sheet members. I'm getting old.

In the early days, such drill screws were tightened by connecting a three-jaw chuck of a general-purpose electric drill to a driver bit instead of a drill. However, since the above-mentioned electric drill was not equipped with a clutch mechanism or a rotational speed control mechanism, the judgment of completion of screw tightening relied on the intuition and skill of the operator. For this reason, it is easy to over-tighten or under-tighten the screws. If the screws are not tightened enough, the object to be fastened may shake, and if the screws are over-tightened, the drill screw may break due to thread cutting or the bit may break. In some cases, the torque transmission mechanism of the engine was damaged.

In order to solve the above problems, electric drills with a built-in percussion clutch mechanism were developed specifically for drilling screws, and have been widely used to this day.Recently, in addition to the percussion clutch mechanism, Electric drills specifically designed for drilling screws that incorporate an electronic speed control device (which can control the rotation speed steplessly in the range of 0 to 2,500 rpm) have appeared and are becoming mainstream.

The above-mentioned electric rotary tool with a built-in impact type clutch mechanism makes it possible to tighten thick metal plates and large diameter drill screws even with a low-power electric rotary tool by utilizing the impact force of the clutch. However, it has the disadvantage that the tightening torque depends on the number of strikes of the clutch and the thrust that provides the striking force, and that the judgment of the thrust and the number of strikes must rely on the intuition and skill of the operator. . Therefore, it is extremely difficult to tighten drill screws using an electric rotary tool equipped with a percussion clutch mechanism, especially when tightening thin plate members that require a small but appropriate tightening torque. It was hot. For this reason, even if the same assembly is fastened using drilled screws, blind rivets, which require a preliminary hole drilling process, are also used to fasten the parts where thin plate members overlap. This is the actual situation.

Although electric rotating tools with built-in torque control devices are also commercially available, these types of electric rotating tools are designed for tightening screws and not for drilling holes, so the rotational speed of the main shaft is between 500 and 700 rpm. Since the rotation speed is extremely low compared to the normal rotation speed of 2500 rpm used in the preliminary hole cutting operation using a drill screw, there is a problem in terms of workability when using such an electric rotating tool to tighten the drill screw. However, it is difficult to adopt in practice and is not used in reality.

The present invention was made in view of the above-mentioned current situation, and its purpose is to drill small-diameter screws using a general-purpose electric drill or an electric drill specifically designed for drilling screws with a built-in impact type clutch. It is an object of the present invention to provide an attachment suitable and effective for fastening drill screws and fastening thin plate members together.

Another object of the present invention is to provide an attachment for an electric rotating tool that does not require any intuition or skill to fasten thin plate members together, and can be performed easily and quickly while maintaining the high speed rotation required for drilling. It is in.

That is, in the attachment of the present invention, a transmission hexagonal bit is provided protruding from one side of the main body case, and a cylindrical shaft for attaching the bit is rotatably supported on the main body case. is operatively connected to the transmission hexagonal bit via a torque limiter built into the main body case.

Therefore, if the attachment of the present invention is attached to the chuck of a general-purpose electric drill or the socket hole for a hexagonal bit of an electric drill specifically designed for drill screws, the drill screw can be tightened with an appropriate torque. When superimposing and fastening thin plate members using screws, no intuition or skill is required at all, and the tightening work can be easily and quickly performed while maintaining the high speed rotation required for drilling work, which is effective. This makes it possible to use drill screws to fasten thin plate members together instead of using blind rivets that require a pilot hole drilling process, greatly increasing the efficiency of construction work, saving labor, and saving manpower. Its economic effects are immeasurable.

In addition, the attachment of the present invention is convenient because it can be easily attached to any existing electric drill, and this is particularly useful for tightening drill screws, which are often used for construction work at construction sites of various buildings. It's advantageous. For example, if you use the attachment of the present invention when performing construction work on high scaffolding at a construction site, you will be freed from the burden of carrying several types of heavy and bulky electric rotary tools, and you will be able to use the lightest general-purpose power drill. There is an advantage that the tightening work of drill screws can be performed easily and quickly using a rotary tool. On the other hand, even if you have a heavy-duty electric drill, by equipping it with the attachment of the present invention, it is possible to fasten small-diameter drill screws and fasten thin plate members together, which was previously impossible. Become.

Furthermore, if the set torque of the torque limiter built into the attachment is adjustable, a desired tightening torque can be easily obtained depending on the material of the object to be fastened or the size of the drill screw, which is very convenient in use.

Embodiments of the present invention will be described below based on the drawings. 1 is the main body case of the attachment,
It is formed into a cylindrical body with a bottom, and a hexagonal transmission bit 3 extending in the axial direction of the main body case 1 is integrally provided at the center of the bottom part 2 to protrude. The transmission hexagonal bit 3 has the same size and shape as a 1/4'' size hexagonal bit so that it can be inserted into a hexagonal bit socket hole of an electric drill exclusively used for drilling screws.

Reference numeral 4 is a cylindrical shaft for attaching a bit, the front half of which is provided with a hexagonal hole 5 into which the bit is inserted, and the rear portion provided with a stopper for the bit inserted into the hexagonal hole 5 and a stop plate for installing a torque limiter to be described later. A screw hole 6 into which a stopper 7 which also serves as a lock is screwed is provided, and an engaging portion 8 having a hexagonal cross-sectional shape is formed on the outer periphery of the rear end. The hexagonal hole 5 is 1/1 like the bit 3 above.
4" size is preferable. Also, the cylinder shaft 4
A through hole 9 extending from the outer peripheral surface toward the center and communicating with the hexagonal hole 5 on the inside thereof is bored in the front half of the hole 9 . The through hole 9 has a constricted shape so that the inner opening 10 has a slightly smaller diameter, and a portion of the locking sphere 11 fitted in the through hole 9 projects from the opening 10 toward the hexagonal hole 5 side. On the other hand, through hole 9
An annular spring 13 is fitted into an annular groove 12 provided on the outside of the sphere, and the annular spring 13 presses the sphere 11 to constantly urge it to protrude toward the hexagonal hole 5 side. Then, by engaging the sphere 11 with the locking groove 31 of the Phillips screwdriver bit 30 or the hexagonal socket bit 30' inserted into the hexagonal hole 5, the bit 30 or 3 is inserted into the hexagonal hole 5.
0' is fixedly held on the cylinder shaft 4. The cylindrical shaft 4 is rotatably and slidably supported through a boss portion 15 formed in the center of a lid 14 that is screwed into the opening of the main body case 1, and is coaxially supported with the hexagonal bit 3 for transmission. will be placed. The lid body 14 also serves as a spring pressure adjustment device for controlling the set torque of a torque limiter 16, which will be described later.

16 is a torque limiter built into the main body case 1. The main parts constituting the torque limiter 16, as clearly shown in FIG. a disk 17 having three roller engaging grooves 21 extending therefrom and arranged with a phase difference of 120 degrees; and a hole 2 in the center that loosely fits into the cylindrical shaft 4.
2 and provided with three roller accommodating notches 23 corresponding to the roller engaging grooves 21 extending in the radial direction continuously from the holes 22, and a roller presser washer 19. Retainer 18
An annular covering part 24 is connected to the outer circumferential part, and a pair of locking notches 25 are provided at diametrically opposed positions on the side edges of the annular covering part 24.

The torque limiter 16 is constructed by incorporating each of the above-mentioned components 17, 18 and 19 into the main body case 1 as shown in FIG. That is, the disc 17 is fitted into the rear end engaging portion 8 of the cylinder shaft 4 and is prevented from moving rearward by the stopper plug 7. The retainer 18 that is loosely fitted to the cylinder shaft 4 has an annular covering part 24 deep inside the main body case 1.
is fitted so as to surround the disc 17, and a set screw 26 screwed through the bottom 2 of the main body case 1 is engaged with the locking notch 25, so that it is in a non-rotating state with respect to the main body case 1. can be attached to. The rollers 27 accommodated and held in the respective roller accommodation notches 23 of the retainer 18 are arranged so as to engage with the engagement grooves 21 of the disc 17, respectively. In addition, the cylinder shaft 4
The presser washer 19 loosely fitted into the washer 19 and the lid body 14
The roller 27 is always urged to be pressed against the disk 17 by the spring pressure of a coil spring 28 interposed between the roller 27 and the disk 17. The torque limiter 16 incorporated into the main body case 1 in this manner is configured to be able to control the set torque by adjusting the spring pressure of the coil spring 28 by adjusting the amount by which the lid 17 is screwed into the main body case 1. has been done.

As illustrated in FIG.
It is used by being attached to a chuck 37 attached to the tip, and the transmission hexagonal bit 3 is inserted into the chuck 37 to connect and hold it, and a specified Phillips screwdriver bit 30 is inserted into the hexagonal hole 5 of the cylindrical shaft 4. Tighten the drill screw S with the driver bit 30. At that time, the main shaft 36 rotates at high speed (usually
2500r.pm) is the chuck 37, the attachment body case 1, the torque limiter 16, and the cylinder shaft 4.
is directly transmitted to the driver bit 30 via
The drill screw S is tightened by the driver bit 30 rotating at high speed. Therefore, the tightening efficiency is extremely high.

Then, when the drill screw S is tightened to a predetermined tightening torque, the torque limiter 16 is activated,
The roller 27 and the engagement groove 21 of the disk 17 repeat the attachment/detachment operation, and the transmission of rotational force from the main body case 1 to the cylindrical shaft 4 is interrupted, and the rotation of the driver bit 30 is stopped. By stopping the rotation, it is confirmed that the drill screw S has been tightened with an appropriate tightening torque, and at the same time, it is determined that the tightening is completed, and the operation moves on to tightening the next drill screw S. In addition, drill screw S
When the head shape is a hexagonal head, a hexagonal socket bit 30' may be inserted into the hexagonal hole 5 of the cylindrical shaft 4 as shown by the imaginary line in FIG.

As described in detail above, by using the attachment of the present invention, it is possible to tighten a drill screw with an appropriate torque simply by attaching it to the main shaft of a general-purpose electric rotating tool. It is effective when overlapping and fastening thin plate members that require appropriate tightening torque, and when used for special small-diameter drill screws.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a longitudinal sectional front view of the attachment according to the present invention, FIG. 2 is an exploded perspective view of the main parts thereof, and FIG. 3 is a front view showing the attachment in use. 1... Main body case, 3... Hexagonal bit for transmission,
4...Cylinder shaft for bit mounting, 16...Torque limiter, 14...Lid body, 15...Boss portion of lid body 14,
30, 30'...driver bit, 35...electric drill, 36...main shaft, 37...chuck.

Claims (1)

[Scope of Claims] 1. A hexagonal bit for transmission is provided protruding from one side of the main body case, and a cylindrical shaft for attaching the bit is rotatably provided on the main body case, and the cylindrical shaft for attaching the bit is rotatably provided. An attachment for an electric rotating tool, characterized in that the attachment is operatively connected to the transmission hexagonal bit via a torque limiter built into the main body case. 2. The attachment for an electric rotating tool according to claim 1, wherein the torque limiter is configured to be adjustable in setting torque. 3. The attachment for an electric rotating tool according to claim 1 or 2, wherein the diameter of the transmission hexagonal bit and the diameter of the hexagonal hole of the cylindrical shaft for bit attachment are 1/4'' size.