JPH01321173A - Thread fastener - Google Patents

Abstract

PURPOSE:To get rid of the idle rotation of a drive bit by providing a head valve which is pushed up when a drive bit which hit against the screw driving face is moved upward to open a motor air passage and which closes this passage when the drive bit for driving the screw on the screw driving face is in its lower end position. CONSTITUTION:By pulling up a trigger 36, a stem valve 32 is switched over, allowing air from an air intake 33 to also flow into an air vent 34 and into a head chamber 31 to push out a sleeve 7 downward. A machine screw is pushed out up to a driving face by means of a drive bit 13 which is one with the sleeve 7. As this machine screw hits against the driving face, the drive bit 13 is pushed up, opening a head valve 20 via a center rod 19 to introduce air into an air motor 9. The introduction of the air rotates the air motor 9 and the drive bit 13, which, in turn, screws in the machine screw. When the machine screw is completely screwed in, the center rod 19 is returned, closing the head valve 20 while stopping the air motor 9.

Description

[Detailed Description of the Invention] (Industrial Application Field) When the trigger is pulled and returned, the feed piston is operated to feed the screw to the tip of the bit, and
This invention relates to a screw tightening machine that rotates a rod-shaped bit using an air motor to screw in a screw.

(Prior Art) As a screw tightening device for screwing screws into a workpiece using power other than human power, there are known devices with various structures for screwing screws by rotating a rod-shaped pit with an air motor or an electric motor. In order to feed the screw to the tip of the pit, the operator must set the screw at the tip of the pit each time he or she screws in the work, or the force that the operator uses to press against the workpiece is accumulated in a spring, and this spring From the knowledge, there is a method to do it through a link, and there is also a version of the above-mentioned version published in 1983.
No. 41021 is known as a feed piston/cylinder device that feeds screws one by one into the nose using a screw feeding claw mechanism. Furthermore, in a screw feed pawl mechanism, a control means for synchronously operating a fastener driver and a fastener feed means is also known (for example, Japanese Patent Laid-Open No. 61-26
No. 0988).

(Problem to be Solved by the Invention) In the device for screwing the rod-shaped pit by rotating it with an air motor, when the motor and drive bit rotate at the 9th point when the trigger is pulled, the tip of the bit does not enter the head groove of the screw. The pit rotates idly, which is inconvenient when tightening screws.

Therefore, the present invention prevents idle rotation of the drive bit by rotating the air motor and the drive bit when the drive bit is pressing the screw on the screw driving surface.
The purpose is to eliminate failures and improve the efficiency of screw tightening work.

(Means for solving the problem) In order to achieve the above object, the present invention pulls up the trigger and switches the stem pulp to guide air into the air chamber, and uses this air pressure to push and support the resleeve downward. The built-in drive bit pushes the screw to the driving surface, and when the screw hits the driving surface, the drive bit that moves upward pushes the center rod upward, opens the head valve, and guides air to the air motor. It is characterized by having a groove so as to rotate the drive bit.

Below, we will explain the drawings showing the embodiments of the present invention. Fig. 1 is a longitudinal sectional view of the basic configuration of a screw tightening machine;
2 is a body in which the grip portion 1 is integrally molded; 3 is a bottom case that is not fixed to the lower end of the tip of the body 1;
- n5 is a magazine case equipped with the feed piston-cylinder device 4 on its side, connected to the feed piston-cylinder device 4 at the front end, and connected to the feed piston-cylinder device 4 at the rear end.
It is fixed to the grip part 2 of the side 1.

An air chamber 6 is provided in the tip of the body 1, and a foam 1-puff is provided in the air chamber 6 so as to be able to slide up and down.
? ln8 is the helad cover of body 1.

An air motor 9 is installed in the upper part of the sleeve 7,
This air motor 9 has a conventionally known structure in which a rotor 11 having several blades rotates inside an air motor cylinder 10. Further, in the lower part of the sleeve 7, a pit sub-shaft 12 which is integrally connected to the rotor 11 is incorporated, and a bit sub-shaft 4+12 and a drive bit 13 are connected via a ball 14. , drive bit 13 from bit countershaft 12
The lower end 13a of this drive bit 13 is prevented from coming off.
faces the upper end of the center hole 3a of the bottom case 3.

The bit sub-shaft 12 and the drive bit 13 are the lower hole 18aK drive pit 1 of the center hole 1s of the bit sub-shaft 12.
By fitting the upper ends of 3, they are coupled together so that they can rotate together. Further, as described above, an annular groove is provided on the outer periphery of the drive bit 13 to form a small diameter neck portion 16, into which the steel ball 14 supported by the bit countershaft 12 is engaged.

The neck portion 16 of the drive bit 13 has a predetermined vertical length, and the neck portion 16 of the drive bit 13 has a predetermined length in the vertical direction.
3 is provided to be able to move up and down. , 17 is a cap cylinder that supports the steel hole 14. Center hole 15 of bit subshaft 12
The upper part K> communicates with the center hole 18 of the rotor 11, and the center rod 19 is inserted into these center holes 111.

The center rod 1s is equipped with a head valve 20 at its upper end, and a valve hole 22 of a sleeve middle sleeve 21 can be opened and closed.
When the valve hole 22 is closed, the lower part contacts the drive bit 13 and pushes it downward.

23 is an air motor cylinder, and the upper end of the rotor 11 is fixed to the shaft. , 24 is a motor air passage;
The outer end is connected to the valve hole 23 and the inner end is connected to the air motor 9. The head valve 20 is the collar 2B of the pulp rod 2S.
Coil spring 2 is installed between the
7 is provided, and the sealing ring 28 on the lower surface of the collar 26 is connected to the valve hole 22.
Close it by pressing it against it. When the center rod 19 moves upward, the pulp rod 25 protrudes from the center hole 30 of the head valve ram 29, and the sealing ring 28 separates from the valve hole 22.
The head chamber 31 and the motor air passage 24 communicate with each other. , 32 is a stem pulp, and an air vent hole 3 that communicates air from an air intake port 33 to the head chamber 31.
4 and air chamber 77 vent 3 leading to air chamber 6
f13B, which switches to s, is a trigger. , 37 are screw feed ventilation holes, and fi 38, which communicates with the head chamber 31 and the feed piston/cylinder device 4, is an exhaust hole.

(Function) In FIG. 1, air entering from the air intake port 33 passes through the air chamber ventilation hole 35 and enters the air chamber 6. Head valve 20 is closed. Air motor 9
has also stopped. As shown in FIG. 4A, the feed piston 39 is also pushed back by the feed spring 40.

As shown in FIG. 2, when the trigger 36 is pulled up, the stem pulp 32 switches and the air entering from the air intake port 33 also flows into the air vent 34 through the throat chamber 31.
flows into the sleeve and pushes the sleeve downward. When the sleeve 7 is lowered, it is assembled into the sleeve 7 and the ratio drive bit 13 pushes out the screw 41 to the driving surface. When the screw 41 hits the driving surface, the drive bit 13 is pushed up, and the center rod 19 is pushed upward accordingly. The pushed up center rod 19 pushes up the head valve 20, opens the pulp 20, introduces air into the air motor 9, and rotates the air motor 9 and drive bit 13. Screw 4
Since the drive bit 13 is always in contact with the screw groove 1 and fitted into the screw groove, the drive bit 13 does not rotate idly. The sleeve 7 is gradually pushed downward, and the built-in air motor 9 and drive bit 13 rotate, and the drive bit 13 is rotated.
Then screw in screw 41. If the screw 41 is completely screwed in, the center rod 19 will return and the head valve 8
is closed, and the air motor 9 and drive bit 130 stop rotating.

When the sleeve flap is gradually pushed downward and the screw 41 is screwed in, if the sleeve flap falls below the position of the screw feed vent hole 3, air flows from the same vent hole 37 into the chamber of the feed piston 3g as shown in Figure 4. Push the feed piston 39 toward the magazine case S side. trigger 36
When the operating finger is released from the head chamber 31, the air in the head chamber 31 is released from the stem pulp 32, and the sleeve 7 returns upward. At 9 o'clock, when the sleeve flap returns above the screw feed vent hole 3, the air in the feed piston 39 chamber is released, and the next screw 41& is sent to the center hole 3a of the bottom case 3 by the spring 40 built into the rear surface of the feed piston 39. still,
42 is a feed finger.

(Effects) Since the present invention is constructed as described above, the screw is pushed out to the driving surface, and when the screw hits the driving surface, the center rod is pushed upward by the upwardly moving drive bit and the head The valve is opened to guide air to the air motor, and with the drive bit fitted into the groove of the screw, the motor and drive bit rotate, eliminating idle rotation of the drive bit, preventing breakdowns, and improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the whole, FIG. tX2 and IE8 are partial longitudinal sectional views, and FIG. 1...Body 6...Air chamber buff...Sleeve 9...Air motor 12...Rod subshaft 13...Drive bit Is@@, Center rod 20...-Head valve 24... Motor air passage 36...Fist trigger

Claims (2)

[Claims] (1) Connect the rod-shaped drive bit 13 to the air motor 9.
In a screw tightening machine that screws in a screw 41 by rotating it with is coupled to the motor drive shaft 11a at the bottom and incorporates a rod subshaft 12, and a drive bit 1 is attached to the lower end of the rod subshaft 12.
The upper end portions of the rod subshaft 12 and the air motor 9 are connected to each other so as to be integrally rotatable, and a telescopic sliding portion that can move up and down by a predetermined width is provided at the joint portion of both of them. A center rod 15 is inserted through the rotor shaft, and a head valve 20 is provided at the upper end of the center rod 15, and the head valve 20 is screwed into a valve hole 22 at the center of a sleeve cap 21 fixed to the upper end of the sleeve 7. When the drive bit 13 in contact with the screw driving surface is moved upward, it is pushed up to open the motor air passage 24, and the motor air passage 24 is closed at the lower end position of the drive bit 13 where the screw 41 on the screw driving surface is screwed. Characteristic screw tightening machine. (2) A small diameter neck portion 16 is provided at a predetermined length on the outer periphery of the drive bit 13 fitted to the lower end portion of the rod countershaft 12;
2. The telescopic sliding part according to claim 1, wherein a steel ball 14 supported by the rod sub-shaft 12 is engaged with the neck part 16.