JPS6048308B2 - Vacuum suction type automatic screw tightening machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw tightening machine equipped with an automatic screw supply device, and in particular to a suction port and a bit for an automatic screw tightening machine that tightens cross-recessed screws and hexagon socket head screws by vacuum suction. It provides:

− to A) −1−1 In one arc A, ι, +,) ← N;μ
Roroto 11 is the guide part for the bit 3 of the suction port 4,
Its inner diameter is approximately O, 5m77, than the outer diameter of bit 3! It's reasonably big.

The gap 2 created by this diameter difference becomes an air passage for sucking the screw 5 from the tip of the suction port 4 by vacuum suction. The inner diameter of the tip of the suction port 4 is approximately O from the head diameter of the screw 5.
, 5TTUTL, so that the screw 5 can be inserted smoothly.

However, since there is a gap 2 between the bit 3 and the bit guide section 1, the bit 3 tends to be guided eccentrically so as not to coincide with the center of the bit guide section 1, as shown in FIG.
Vacuum suction type screw tightening machines are generally used for tightening screws in narrow spaces such as deep holes, so the bit holder 6 and suction pipe 7 are long, so they are not concentric with the suction pipe 7. It is difficult to maintain the fixed suction port 4 and the bit 3 fixed at the tip of the bit holder 6 in a concentric state. Also, if this gap 2 is eliminated, the screw 5 cannot be sucked into the suction port 4 even if the inside of the suction pipe 7 becomes a vacuum.If the gap 2 is further reduced, the amount of air sucked from the suction port will be reduced. As a result, the screw 5 may not be able to be sucked up. Therefore, in order to provide the gap 2 with a certain size, the bit 3 is eccentric to the suction port 4. For example, as specified in JIS, the tolerance for M4 cross-recessed pan head machine screws is 7° - 0.°. Therefore, in order to tighten M4 + shaped recessed pan head machine screws, , the inner diameter of the suction port 4 needs to be about 7.3Tnn1, taking into account the allowance.When the screw 5 is suctioned with such a dimensional relationship, the screw 5 will not fit between the tip of the bit 3 and the inner wall of the suction port 4. They come into contact with each other and are attracted at an angle.

Since the bit 3 is rotated before tightening the screw 5 to the workpiece, the screw 5 rotates in a tilted state and hits the top surface of the workpiece, preventing it from entering the blank hole 34 and pilot hole 35, making it impossible to completely tighten the screw. Not possible. Also, the stupid hole 35 and the pilot hole 36
If the screw 5 is eccentric to the suction port 4, even if the screw 5 is upright, the screw 5 rotates against the top surface of the workpiece, scratching the workpiece and sucking in the chips. Therefore, the chips clog the suction passage and the filter, resulting in a decrease in the suction force, and eventually the screw 5 cannot be suctioned. The present invention eliminates the above-mentioned conventional drawbacks and provides an automatic suction type automatic screw tightening machine that holds the screw upright and prevents chips from entering when the screw starts to be tightened. This will be explained based on FIGS. 1 to 8.

Reference numeral 8 denotes a fixed bracket, to which a piston rod 10 of a cylinder 9 and a guide 11 are fixed.

12 is the driver base, this driver base 12
As shown in FIG. 1, a cylinder 9 is fixed to the right side, a driver 13 is fixed to the left side, and a bearing 14 that is slidable on the guide 11 is fixed to the center part.

15 is a female tapered cylinder, and the lower part. A female taper 16 is formed at the center of the female taper 16 and the driver 13.
are fixed to the driver base 12 with their centers aligned.

6 is a bit holder, which is connected to the driver 13 by a joint 17.

7 is an adsorption vibrator, and a male taper 18 that fits into the female taper 16 is formed at the upper part, and a through hole 19 is provided at the top so that the bit hole 6 can be slid and rotated to maintain airtightness. Formed concentrically with the center of 13
There's no.

A compression spring 20 is set between the upper end surface of the driver 13 and the suction vibrator 7, and is always biased so that the female taper 16 and male taper 18 fit together, and the center of the driver 13 is aligned with the bit holder 6. It is designed to fit the center.The suction port 21 is located on the upper side of the suction vibrator 7.
is fixed, and a tube 22 is connected to the tip. Compressed air is put into the cylinder 9, and the screwdriver 13 begins to rotate and descend.At the same time, air is sucked in from the tuner 22, and when the screw tightening is completed, the suction is stopped, and at the same time, the cylinder 9 rises together with the screwdriver 13, which has stopped rotating. do. Reference numeral 23 denotes a suction port, in which a hole 24 slightly larger than the head diameter of the screw 5 is formed in the lower part, and a bit guide hole 26 which is 0.0 ITWL larger than the outer diameter of the bit 25 is formed in the center.

Note that the bit 25 is concentric with the bit holder 6 and fixed to the bit holder 6. A pair of slanted chutes 27 are fixed to the lower end of the bracket 8, and the interval between the pair of chutes 27 is slightly larger than the diameter of the lower neck of the screw, and the screws are fed one by one in a hanging state. Reference numeral 28 denotes an L-shaped catcher, which is swingably attached to the bracket 8 by a shaft 29. A compression spring 30 is set on the upper part of the shaft 29 between the L-shaped catcher 28 and the bracket 8. The tip of the catcher 28 is biased so as to come into contact with the end of the chute 27.

A U-shaped notch 31 is formed at the tip of the L-shaped catcher 28 to capture the screws sent one by one from the chute 27 so that the center of the screw head coincides with the center of the bit 25. There is. While sucking air from the suction port with the screw captured in the L-shaped catcher 28,
Further, as the bit 25 rotates and descends, the screw is sucked into the hole 24. A flat part 32 is formed at the bottom of the bit, and the sucked air passes through a gap 34 between the flat part 32 and the bit guide hole 26, passes through the inside of the suction vibrator 7, and enters the suction port 21, It reaches the tube 22. The cross-recessed machine screw sucked into the suction port 23 is attached to the bit 25.
It gets stuck in the cross section and begins to rotate. At this time bit 2
5 rotates without eccentricity because the outer portion 33 other than the flat portion 32 is guided by the bit guide hole 26. Therefore, the screw fitted into the bit 25 also rotates in an upright state without eccentricity. Therefore, it is located concentrically with the blank hole 35 and pilot hole 36 of the workpiece fixed coaxially with the suction vibrator 7, allowing smooth and complete screw tightening. As shown in FIG. 5, when the tightening is completed, the bit flat part 32 is separated from the bit guide hole 26, and air is sucked into the outer diameter part 33 of the bit 25.
It has been stopped by.

That is, the suction of air stops when it comes into contact with the workpiece, the bit 25 rotates and descends further, the screw picks up the blank hole 35 and the pilot hole 36, and the bit 25 descends further to tighten the screw. At the beginning of this screw tightening operation, the bit flat portion 32 separates from the bit guide hole 26, and air inflow stops. This prevents chips generated by contact between the bit 25 and the screw during tightening from flowing into the suction vibrator 7. Also, chips generated in the case of screws, etc., can be similarly prevented. The timing at which the intake air stops when tightening a screw needs to be adjusted appropriately depending on the length of the screw. Let's go.

For this reason, the driver base 12 is provided with a slit 37, and by slightly opening and closing the driver holding portion with a screw 38, the driver 13 can be held in a vertically adjustable state. There is. Also, 3
Reference numeral 9 denotes a first stopper fixed to the suction vibrator 7, which limits the amount of movement of the suction vibrator 7 or the female taper tube 15; This is a second stopper that regulates the amount of movement. As described above, according to the present invention, the screw is made to stand upright and the screw is completely tightened, and at the same time,
It has an excellent effect of preventing the inflow of chips generated during tightening, and its industrial value is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a main front sectional view of an automatic screw tightening machine according to an embodiment of the present invention, Fig. 2 is a top view of the same, Fig. 3 is a bottom view of the same,
Figure 4 is a cross-sectional view of the main part showing the air intake port, and Figure 5 is a sectional view of the main part showing the air intake port.
6 is a front sectional view of the main part when tightening is completed, FIG. 6 is a cross-sectional view taken along line AA' shown in FIG. 8, and FIG. 7 is a cross-sectional view taken along line AA' when screw tightening is completed, FIG. 8 is a sectional view of the suction port during screw suction, FIG. 9 is a cross-sectional view taken along the line B-B' in FIG. 11 in the conventional example, and FIG. 10 is the same B-B showing the bit eccentric state. 11 is a cross-sectional view of the suction port of a conventional example showing a state in which the screw is collapsed. 5...Screw, 6...Bit holder,
7...Adsorption vibe, 11...Guide,
13... Driver, 23... Suction port, 25... Bit, 26... Bit guide hole, 27... Chute, 28... ...Catcher, 34...Aisle section (gap).

Claims (1)

[Scope of Claims] 1. A catcher capable of holding screws arranged and supplied one by one from a chute, a cylindrical interior maintained in a vacuum state, and a tip portion capable of suctioning screws from the catcher, The suction pipe is composed of a suction pipe equipped with an internal guide hole having an inner diameter smaller than the inner diameter of the tip, and a bit that can be tightened while rotating a screw and has a notch of a predetermined length in the axial direction. A gap is formed between the guide hole and the notch of the bit to allow the screw to be sucked, and a gap is formed between the guide hole and a portion of the bit other than the notch to maintain airtightness while the bit is slidable and rotatable. What is claimed is: 1. A vacuum suction type automatic screw tightening machine configured to hold the screw, and provided such that the guide hole and a portion of the bit other than the notch face each other at a position where the bit comes into contact with a head of the screw. 2. The vacuum suction type automatic screw tightening machine according to claim 1, wherein the relative position between the bit and the suction pipe is adjustable.