JP3011227B2 - Screw feed mechanism in the screw tightening machine for connecting screws - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a connecting screw screwing machine in which a nose portion having a connecting screw feed wheel is moved in a screw tightening direction with respect to a screw tightening machine body provided with a driver bit. The present invention relates to a screw feed mechanism for feeding a screw.

[0002]

2. Description of the Related Art Generally, a screw feed mechanism of this kind is disclosed in
As shown in JP-A-49879, a feed wheel engaging with a connecting screw is supported by a nose portion, and the feed wheel is superimposed on the feed wheel by a spring force, so that the feed wheel is connected to the nose portion and the screw tightener body. The feed wheel is intermittently rotated in the screw feed direction by engaging the feed wheel with the feed wheel only when the feed wheel is rotated to the screw feed side by using the relative movement of the screw. Many are configured to be sent to a predetermined position every minute.

A mechanism for rotating a feed wheel is provided with a roller at the other end of a feed plate having one end pivotally mounted on the feed wheel, and the roller is provided with guide grooves formed on each side of a nose portion and a screw tightening machine body. When the nose is moved relative to the screw tightener body, the feed plate is reciprocated by moving the rollers guided by the guide grooves, and the feed wheel is reciprocally rotated in conjunction with this. The wheel is configured to rotate intermittently.

By the way, for example, when the nose portion is used with the nose part facing upward, the weight of the connecting screw tends to greatly affect the feed wheel. In this case, the weight of the connecting screw rotates the feed wheel in the reverse rotation direction to the screw feed. The power to do so works. Therefore, when the roller is positioned at the end of the straight portion of the guide groove after the screw tightening is completed, the above-described force in the reverse rotation direction acts, and if the feed wheel rotates slightly in the reverse direction, the feed plate also rotates in the reverse direction. , The roller is pressed against the inner surface of the guide groove.

However, conventionally, there is a slight time lag between the time when the screw is completely tightened and the time when the check mechanism for preventing the feed roller from rotating backward when the nose portion returns is operated. Was. For this reason, since the check mechanism does not operate at the time when the pressing force against the nose portion is released after the screw tightening is completed, as described above, when the force in the reverse rotation direction acts due to the weight of the connecting screw, The feed wheel rotates in the reverse direction, the roller cannot rotate due to the surface pressure between the roller and the inner surface of the guide groove, and the sliding resistance increases, and this resistance becomes larger than the spring force that returns the nose portion. In some cases, the nose portion cannot return to the initial position, and a screw feed failure occurs, which hinders the operation.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and, in particular, to provide a screw feeding mechanism in a screw tightening machine for a connecting screw which can smoothly and reliably return the nose portion.

[0007]

In order to achieve the above object, a screw feed mechanism in a screwing machine for a connecting screw according to the present invention comprises a rotary shaft provided on both side walls of a nose portion, and a connecting screw. The feed wheel and the feed wheel of the screw to be engaged are rotatably supported in an overlapping state, and a plurality of engaging recesses are provided on one of the overlapping surfaces of the feed wheel and the feed wheel, and the engaging claw is provided on the other. Formed on the side of the nose part, a sloped guide groove on the side of the nose part, and a guide groove formed integrally and integrally with the sloped part and the straight part formed in the longitudinal direction on the corresponding side of the screwdriver body. Forming
A roller that engages with the two guide grooves is axially supported at the end of the feed plate that drives the feed wheel, and moves the screw tightening machine body and the nose relatively in the screw tightening direction. Relatedly, the feed wheel is reciprocatedly rotated when the roller is guided and moved along the guide groove, and the engagement claw and the engagement recess are engaged only when the feed wheel rotates in the screw feed direction. ,
When rotating in the opposite direction, the check mechanism of the feed wheel operates to intermittently rotate the feed wheel to feed the connecting screw. The mating engagement side is inclined at a small angle so that the inclined side is higher with respect to the axis of the nose part and the opposite side is lower, and the above-described check mechanism for the feed wheel is operated when screw tightening is completed. It is characterized by being formed in.

The roller includes a first roller engaged with the inclined guide groove and a second roller engaged with the guide groove.
It is preferable to adopt a configuration in which the roller is supported coaxially.

[0009]

According to the first aspect of the present invention, the roller is connected to the inclined guide groove of the nose portion in relation to relatively moving the screw tightening machine body and the nose portion in the screw tightening direction. The feed wheel reciprocates when it is guided and moved along the guide groove of the screw tightener body, and engages the engagement claw and the engagement recess only when the feed wheel rotates in the screw feed direction, When rotating in the reverse direction, the feed wheel is intermittently rotated by operating the check mechanism of the feed wheel, and the connecting screw is fed to a predetermined position.

After the screw is completely tightened, the roller moves in the direction opposite to the direction in which the straight portion of the guide groove is tightened when the nose portion returns. At this time, the feed working reverse rotational force to the feed wheel by the weight or the like of the connecting screw a wheel who attempts reverse rotation, Ne
Check machine for feed wheel when tightening
Since the mechanism works, the feed wheel cannot be reversed,
The feed plate does not move, and the roller does not contact the inner surface of the engagement side of the straight portion of the guide groove. Therefore, there is no rotation resistance between the roller and the straight portion, so that the roller moves smoothly. Moreover, since the upper engaging side is slightly inclined on the side of the inclined portion which is high and the opposite side is low, a gap is generated between the upper engaging side and the roller, and resistance to the roller is eliminated. The movement of the rollers is further smoothed, and the nose portion returns reliably.

According to the second aspect of the present invention, when the roller moves along the inclined guide groove and the guide groove, rotational forces in opposite directions act on the roller due to a difference in inclination between the two guide grooves. However, since the first roller and the second roller rotate independently of each other, the rollers rotate smoothly, and the operation of the feed plate is also performed smoothly. .

[0012]

1 and 2 show a screw feed mechanism according to the present invention. Reference numeral 1 denotes a nose holder provided at the tip of a screw tightening machine main body (not shown), and 2 denotes a nose portion.

The nose holder 1 is provided with a driver bit 3 and a rotation driving mechanism (not shown).

The nose portion 2 is provided inside the nose holder 1 so as to be able to reciprocate along a screw tightening direction (axial direction of the driver bit 3), and is constantly urged by a spring 5 in a projecting direction (return direction). ing.

The nose portion 2 is provided with a passage 7a for the connecting screw 6 vertically penetrating the connecting screw 6, a screw-in portion 7b arranged in the extension direction of the driver bit 3, and a feed mechanism for the connecting screw 6. ing.

The mechanism for feeding the connecting screw 6 is constructed as follows. That is, the feed shaft 9 and the feed wheel 10 of the screws that engage with the connecting screws 6 are rotatably supported in a superposed state on the rotating shaft 8 provided in the direction penetrating the left and right side walls of the nose portion 2. .

A plurality of engaging recesses 11 (see FIG. 4) are formed on the overlapping surface of the feed wheel 9 in the circumferential direction. One end of the engaging recess 11 is perpendicular to the overlapping surface, and the other end is inclined. In contrast, feed wheel 1
As shown in FIG. 3, a reference numeral 0 denotes a non-circular elongated shape, and one end thereof has a fitting hole 12 fitted to the rotary shaft 8.
However, one engagement claw 13 corresponding to the engagement recess 11 of the feed wheel 9 is formed on the overlapping surface at the other end.
In the normal case, the engaging claw 13 and the engaging concave portion 11 are
They are engaged as shown in (a).

By the way, the feed wheel 9 is constituted by a check mechanism so as not to rotate in the direction opposite to the screw feed direction. As shown in FIG. 5, the check mechanism includes a check claw 14 rotatably supported on the opposite side of the feed wheel 9 from the overlapping surface, a ratchet groove 15 formed on the outer peripheral surface of the rotating shaft 8, and The check claw 14 is spring-biased so as to always engage with the ratchet groove 15. For this reason, the feed wheel 9 is rotatable only in the screw feed direction. The timing of the check pawl 14 is set so that it is locked in the ratchet groove 15 without any gap when the screw is completely tightened after the feed is completed.

Next, an end of the feed wheel 10 is connected to one end of a feed plate 17 via a feed rod 16, and a roller 18 is connected to the other end of the feed plate 17.
Is supported. As shown in FIG. 6, the roller 18 has an inner first roller 18a and an outer second roller 18b rotatably supported on a support shaft of the feed plate 17.

A spring 19 is arranged around the feed rod 16 so as to separate the feed plate 17 from the feed wheel 10. The spring 19 causes the feed wheel 10 to be attached to the feed wheel 9. It is being rushed.

Next, an inclined guide groove 20 is formed on the side of the nose portion 2. Correspondingly, a guide groove 21 formed integrally and integrally with the inclined portion 21a and the straight portion 21b formed in the longitudinal direction is also formed on the side of the nose holder 1 on the screwdriver body side. Guide groove 21
The upper engaging side 22 of the straight portion 21b with which the roller 18 is engaged is inclined with respect to the axis of the nose.
The end 22a on the 1a side is high and the end 22b on the opposite side is inclined at a small angle so as to be low (see FIG. 10). This inclination angle α is preferably about 1 ° to 5 °.

The first roller 18a of the rollers 18 of the feed plate 17 is provided with the inclined guide groove 2 of the nose portion 2.
0, the second roller 18b is engaged with the guide groove 21 of the nose holder 1. Therefore, the feed wheel 10 reciprocates when the roller 18 is guided and moved along the guide groove 21 when the nose portion 2 slides.

According to the above configuration, when the screw is tightened, the nose portion 2 is pressed against the surface of the threaded member 23 and the nose portion 2 is pushed and moved with respect to the screw tightening machine main body as shown in FIG. The roller 18 of the plate 17 moves downward while being guided by the inclined guide groove 20 of the nose part 2 and the inclined part 21a of the guide groove 21 of the nose part holder 1.
The displacement movement of the roller 18 causes the feed plate 1
The feed rod 16 at the tip of the feed wheel 10
Is extruded in the screw feed direction and rotated by a certain angle.
At this time, since the engaging claw 13 of the feed wheel 10 and the engaging concave portion 11 of the feed wheel 9 are in the engaged state, the feed wheel 9 also rotates by the same angle, and the connecting screw 6
Is sent by one screw.

When the nose portion 2 is further pushed after the feed of the connecting screw 6 is completed, the rotated driver bit 3 tightens the screw 6a. At the same time, the roller 18 is moved to the upper engaging side 22 of the straight portion 21b. However, since the upper engaging side 22 is slightly inclined, the roller 18 moves further downward, and as shown in FIG. The check pawl 14 engages with the ratchet groove 15 of the rotating shaft 8.

Next, after the screw is completely tightened, the roller 18 moves the straight portion 21b in the reverse direction when the nose portion 2 returns by the spring 5. At this time, FIG.
As described above, even if the feed wheel 9 is rotated in the reverse direction by the force of the reverse rotation acting on the feed wheel 9 due to the weight of the connecting screw 6 or the like, when the screw is completely tightened , the feed wheel 9
Since the above-described check mechanism operates, the feed wheel 9 cannot rotate in the reverse direction, so that the feed plate 17 does not move.
The roller 18 does not come into pressure contact with the inner surface of the upper engaging side 22 of the straight portion 21b of the guide groove 21. Therefore, there is no rotation resistance between the roller 18 and the straight portion 21b, so that the roller 18 moves smoothly. Moreover, since the upper engagement side 22 is slightly inclined,
As shown in FIG. 10, the upper engagement side 22 and the roller 18
And the resistance to the roller 18 at the time of return becomes very small.
Is smoother, and the nose portion 2 can reliably return.

When the nose portion 2 returns, the roller 18 moves upward while being guided by the inclined guide groove 20 of the nose portion 2 and the inclined portion 21a of the guide groove 21 of the screw tightener body. Due to the displacement movement of the roller 18, the feed rod 16 at the tip of the feed plate 17 pulls the feed wheel 10 in the direction opposite to the screw feed and rotates the feed wheel 10 in the opposite direction by a certain angle. At this time, as shown in FIG. 4 (b), the engaging claw 13 of the feed wheel 10 separates from the engaging recess 11 of the feed wheel 9 and slides on the overlapped surface to engage with the next engaging recess 11. Then, the next screw feed is prepared.

Further, as described above, the roller 18 has the inclined guide groove 20 of the nose portion 2 and the guide groove 2 of the screw tightener main body.
As shown in FIG. 11, when the first roller 18a moves upward or downward while being guided by the first inclined portion 21a, the peripheral surfaces of the first roller 18a and the second roller 18b
Since the first roller 18a and the second roller 18b intersect with each other and come into contact with sides that are inclined to the opposite sides, forces that rotate in the opposite directions act on the first roller 18a and the second roller 18b. However, as shown in FIG. 6, since the first roller 18a and the second roller 18b rotate independently of each other, the roller 18 rotates smoothly, and the operation of the feed plate 17 is also performed smoothly.

By repeating the above operation, the feed wheel 9 rotates intermittently in the screw feed direction, and the screw is fed one by one to the screwed portion.

[Brief description of the drawings]

FIG. 1 is a plan view of a screw tightening machine for a connecting screw according to the present invention.

FIG. 2 is a side view of the screw tightening machine.

FIG. 3 is a perspective view of a feed wheel.

FIGS. 4 (a) and (b) are explanatory views of an engagement state between an engagement claw of a feed wheel and an engagement groove of a feed wheel.

FIG. 5 is a side view of the screw tightening machine showing a check mechanism.

FIG. 6 is an enlarged view of a roller portion.

FIG. 7 is an explanatory view of a screw feeding completed state by the screw feeding mechanism.

FIG. 8 is an explanatory view of a state in which screw tightening by a screw feed mechanism is completed.

FIG. 9 is an explanatory diagram of an operation state of the check mechanism when the nose portion returns.

FIG. 10 is an enlarged view showing a state where a roller moves along a straight portion of a guide groove.

FIG. 11 is an enlarged view showing a state where a roller moves along two guide grooves.

[Explanation of symbols]

 2 Nose part 6 Connection screw 8 Rotating shaft 9 Feed wheel 10 Feed wheel 11 Engagement recess 13 Engagement claw 18 Roller 18a First roller 18b Second roller 20 Inclined guide groove 21 Guide groove 21a Inclined section 21b Straight section 22 Upper part Engagement side

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B25B 23/04

Claims (2)

(57) [Claims] 1. A feed shaft and a feed wheel of a screw that engages with a connecting screw are rotatably supported in a stacked state on a rotation shaft provided on both side walls of a nose portion, and the feed wheel and the feed wheel are stacked. A plurality of engagement recesses are formed on one side of the surface, and an engagement claw is formed on the other side in the circumferential direction. A guide groove formed integrally and continuously with the inclined portion and the straight portion formed in the longitudinal direction is formed. A roller that engages with the two guide grooves is provided at an end of a feed plate that drives the feed wheel. The feed wheel is reciprocatedly rotated when the roller is guided and moved along the guide groove in relation to moving the screw tightening machine body and the nose portion relatively in the screw tightening direction. Only when the feed wheel rotates in the screw feed direction, the engaging claw and the engaging recess engage with each other. When the feed wheel rotates in the opposite direction, the feed wheel intermittently rotates due to the operation of the feed wheel check mechanism. In the screw tightening machine for a connecting screw that sends the connecting screw, the engaging side of the straight portion of the guide groove, in which the roller is engaged, has a higher inclined side with respect to the axis of the nose portion ,
A screw feed mechanism for a screw tightening machine for a connecting screw, characterized in that the opposite side is inclined at a small angle so as to be lower, and the above-described check mechanism for the feed wheel is operated when screw tightening is completed. 2. The roller according to claim 1, wherein the roller coaxially supports a first roller engaged with the inclined guide groove and a second roller engaged with the guide groove. Screw feed mechanism in the screw tightening machine for connecting screws.