JP2008161984A - Screw feeding device for screw fastening machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that when a feeder box is retracted with respect to a case by conventional screw fastening operation, a screw connecting band is drawn by the retraction and screws are entangled with each other, in a screw feeding device for performing pitch feeding of the screw connecting band holding a large number of screws in parallel to a screw fastening machine main body side. <P>SOLUTION: A clearance 31e along the reciprocating direction of the feeder box 22 is provided in a fixation part 31 of a screw connecting band guide member 30, so as to separate the screw connecting band J from a guide path and move the screw connecting band J to a shortest route across the clearance 31e when the feeder box 22 is retracted. Thus, this can prevent increase in the number of screws S and the length of a sheet material T in a region between the clearance 31e and the feeder box 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a screw feeding device provided in a screw tightening machine main body, and relates to a screw feeding device that supplies screws to a driver bit one by one in conjunction with a screw tightening operation of the screw tightening machine main body.

Conventionally, in order to improve the efficiency of multiple screw tightening operations, one screw at a time is attached to the driver bit one by one in conjunction with the screw tightening operation of the screw tightening machine main body (down operation in the screw tightening direction by the user). There is provided a screw feeder that is automatically supplied.
This screw feeder is supported at the front end of the screw tightener main body so that the driver bit is positioned on the inner peripheral side and reciprocally movable along the driver bit on the inner peripheral side of the case. The feeder box and a screw connection band guide member that guides a belt-like screw connection band holding a number of screws in parallel to the sheet material at regular intervals to the screw connection band entrance of the feeder box. Is equipped with a ratchet mechanism for pitch-feeding the screw connection band in conjunction with the screw tightening operation of the screw tightening machine main body.
In the following explanation, the operation in which the feeder box moves up relative to the case by the push-down operation of the screw tightening machine body is referred to as the backward movement of the feeder box, and the feeder box moves from the case by the lifting operation of the screw tightening machine body. The relative downward movement is called the forward movement of the feeder box.
According to such a screw feeder, the ratchet mechanism is actuated at the start of the retreating operation of the feeder box by the push-down operation of the screw tightening machine body, and the screw connection band is fed by one pitch so that one screw is applied to the driver bit. Supplied. This eliminates the need for the user to set one screw at a time for the screwdriver bit for each screwing operation, so that a number of screwing operations can be performed efficiently and quickly.
The screw connection band guide member holds a long screw connection band in a state where it protrudes from the vicinity of the screw connection band entrance of the feeder box to the rear side in the feed direction. It is hung down near the part so as not to disturb the work, and the screw is held in a fixed posture and supplied to ensure reliable screw feed by the ratchet mechanism.
U.S. Pat. No. 7,032,482

However, the conventional screw feeder, particularly the screw connection band guide member, has the following problems. The conventional screw connection band guide member is fixedly provided to the screw tightening machine main body. On the other hand, the feeder box equipped with the ratchet mechanism reciprocates in the case for each screw tightening operation as described above. For this reason, conventionally, when the feeder box is retracted (upwardly moved) with respect to the case by the push-down operation of the screw tightening machine main body, the screw connection band is folded and caught at the front end of the screw connection band guide member in the feed direction, and as a result Since the screw connection band does not move smoothly following the feeder box, it may be pulled between the feeder box and the feeder box may be retracted, and thus the forward operation may not be smoothly performed. .
In particular, the longer the screw length of the screw to be tightened (the screw length of the screw held in the screw connection band), the longer the reciprocating distance of the feeder box. In this case, the screw connection band is fed by the screw connection band guide member. It tends to be folded and caught at the front end of the direction, and as a result, the backward movement and forward movement of the feeder box are likely to be hindered.
Accordingly, the present invention provides a technique for ensuring a smooth operation of a feeder box that reciprocates with respect to a screw tightening machine main body for each screw tightening operation by incorporating a ratchet mechanism that pitch-feeds a screw connection band. With the goal.

For this reason, the present invention is a screw feeding device having the configuration described in each of the claims.
According to the screw feeding device of the first aspect, the feeder box reciprocates along the case by the screw tightening operation of the screw tightening machine body, whereby the screw connection band is pitch-fed and the screw is 1 with respect to the driver bit. Supplied one by one. The screw connection band is guided to the vicinity of the screw connection band entrance of the feeder box by the screw connection band guide member. The screw connection band guide member is supported on the screw tightening machine main body side. For this reason, when the feeder box reciprocates with respect to the case in accordance with the screw tightening operation, the screw connection band entrance is displaced with respect to the feed direction front end portion of the screw connection band guide member.
For this reason, conventionally, for example, when the feeder box is moved backward with respect to the case by the push-down operation of the screw tightening machine main body, the screw connection band entrance of the feeder box is in the same direction with respect to the front end of the screw connection band guide member. As a result, the screw connection band may be folded and caught at the front end of the screw connection band guide member, or the movement of the feeder box may be hindered due to the screws becoming entangled with each other. .
However, according to the screw feeding device of the first aspect, the screw connection band can move along the gap in a state of crossing the gap formed between the sheet holding portions as the feeder box moves backward. Since the length of the screw connection band is maintained almost constant in the range from the screw connection band guide member to the screw connection retraction inlet, the feeder box is not folded back as in the prior art, and therefore the feeder box is retracted. Is not inhibited.
Further, as the feeder box moves forward, the screw connection band moves to the front end side along this gap in a state of crossing between the sheet holding portions. Normally, the screw connection band is pitch-fed at the time when the push-down operation of the screw tightener body starts and when the feeder box starts to move backward with respect to the case. For this reason, according to the screw feeding device of the first aspect, the screw connection band is moved from the rear side in the feeding direction to the front side by the operation of the feeder box moving forward with respect to the case by the pulling operation of the screw tightening machine main body. It gradually returns to the guiding state between the two sheet holding parts, and when the forward movement of the feeder box is completed, the screw connection band returns to the guided state in the entire range up to the tip of the screw connection band guide member. Therefore, the function of the screw connection band guide member can be sufficiently exerted during the pitch feed, and a smooth movement state of the screw connection band can be ensured.
According to the screw feeding device of the second aspect, it is possible to reliably shift the screw coupling band to the state across the gap between the two sheet holding portions by the backward movement of the feeder box with respect to the case.
According to the screw feeding device of the third aspect, the forward movement of the feeder box with respect to the case ensures that the screw connection band is guided from the state across the gap between the two sheet holding parts to the state guided between the two sheet holding parts. Can be restored.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a screw tightening machine 1 provided with a screw feeder 20 according to this embodiment. A screw feeding device 20 is provided at the distal end portion (lower end portion in FIG. 1) of the screw tightening machine main body 2 of the screw tightening machine 1. The present embodiment has a great feature in the screw feeder 20, and the screw tightening machine body 2 is the same as the conventional configuration and is not particularly necessary in the present embodiment, but will be briefly described below. In the following description, the axial direction in which the screw is tightened is referred to as the vertical direction. In FIG. 2, the screw S is tightened downward with respect to the screw fastening material M.
The screw tightening machine main body 2 incorporates an electric motor 3 as a drive source. The rotational output of the electric motor 3 is transmitted to the first intermediate gear 5 through the drive gear 4. The first intermediate gear 5 and the second intermediate gear 6 rotate together. The second intermediate gear 6 is meshed with the driven gear 7.
A spindle 8 is supported so as to be movable in the axial direction with respect to the driven gear 7 and relatively rotatable about the axis. Between the flange portion 8a of the spindle 8 and the driven gear 7, a meshing clutch 9 and a compression spring 10 that urges the clutch 8 in a direction to disengage it are interposed. The spindle 8 is supported so as to be rotatable about its axis and movable in the axial direction via a cylindrical bearing 13 attached to the lower end of the main body housing 12.

A long driver bit 15 is coaxially attached to the tip of the spindle 8. The driver bit 15 is mounted so as to extend downward from the lower end of the screw tightening machine main body 2, and the tip side thereof reaches the vicinity of the feeder box 22 of the screw feeder 20.
A handle portion 11 is provided at the rear portion (upper portion in FIG. 1) of the screw tightener main body 2. A trigger-type switch lever 14 is provided inside the handle portion 11. A battery pack 16 as a power source is attached to the end of the handle portion 11. When the switch lever 14 is pulled, the electric motor 3 is activated and the driven gear 7 rotates. At this stage, since the clutch 9 is not engaged, the spindle 8 and the driver bit 15 do not rotate. The head of one screw S is set at the tip of the driver bit 15. In this state, the user pushes down the screw tightening machine main body 2 in the screw tightening axis direction (downward in FIG. 1), and the tip of the screw S is moved. When pressed against the screw fastening material M, the spindle 8 moves up against the compression spring 10, whereby the meshing clutch 9 is meshed, and the rotation of the driven gear 7 is transmitted to the spindle 8. It rotates in the direction of screw tightening rotation. When the user presses the screw tightening machine main body 2 against the screw tightening material M while rotating in the screw tightening rotation direction, the screw S is tightened into the screw tightening material M.

The screw feeder 20 according to the present embodiment includes a case 21 attached to the screw tightening machine main body 2, a feeder box 22 supported so as to be able to reciprocate up and down with respect to the case 21, and a screw connection to the feeder box 22. A screw connection band guide member 30 for guiding the band J is provided. The case 21 is fixed to the lower end of the screw tightening machine main body 2 by clamping the upper end of the case 21 to the bearing 13. The case 21 has a rectangular cylindrical shape, and a block-shaped feeder box 22 is accommodated inside the case 21 so as to be movable back and forth (movable back and forth). Further, the tip end portion of the spindle 8 and the driver bit 15 are projected into the case 21.
A compression spring 23 is interposed between the feeder box 22 and the inner part of the case 21. The feeder box 22 is urged by the compression spring 23 in the direction of moving forward with respect to the case 21. This direction is the direction in which the screw S is tightened with respect to the screw fastening material M (the tightening direction of the screw S).
A frame-shaped stopper member 40 is attached to the lower portion of the feeder box 22. The lower part of the stopper member 40 is abutted against the screw fastening material M. The stopper member 40 can be adjusted stepwise in accordance with the length of the screw S for tightening the vertical position with respect to the feeder box 22.
A screw feed mechanism 50 is incorporated in the feeder box 22. The screw feed mechanism 50 includes a drive wheel 51 having meshing teeth around it and a feed wheel 52 having a driven gear portion meshed with the meshing teeth of the drive wheel 51. The drive wheel 51 and the feed wheel 52 are incorporated in the feeder box 22 so as to be rotatable around rotation axes parallel to each other. On the rotational axis of the drive wheel 51, an operating arm 51a is supported so as to be tiltable. A guide roller 51b is attached to the tip of the operating arm 51a. The guide roller 51 b enters a guide hole 21 a provided on the side of the case 21. The guide hole 21a is formed vertically long along the driver bit 15, and its lower end is inclined to the left in FIG. Hereinafter, the range along the driver bit 15 is referred to as the straight portion 21b of the guide hole 21a, and the inclined range at the lower end thereof is referred to as the inclined portion 21c.
A ratchet mechanism (one-way clutch mechanism) that meshes only in the screw feeding direction is provided between the operating arm 51a and the drive wheel 51.

As will be described later, when the feeder box 22 is retracted upward with respect to the case 21, the guide roller 51b enters the straight portion 21b from the inclined portion 21c of the guide hole 21a, and therefore the operating arm 51a is rotated clockwise in FIG. Tilt by a certain angle. The tilting motion of the operating arm 51a is transmitted to the drive wheel 51 by the meshing of the ratchet mechanism, whereby the drive wheel 51 rotates clockwise (screw feed direction) by a certain angle (one pitch) in FIG. . When the drive wheel 51 rotates by one pitch in the feed direction, the feed wheel 52 rotates by one pitch in the counterclockwise direction (screw feed direction) in FIG.
Around the feed wheel 52, feed claws 52a to 52a are provided in a state protruding in the radial direction at regular intervals in the circumferential direction. When the feed wheel 52 is intermittently rotated and the feed claws 52a are sequentially engaged with the notches t of the screw connection band J, the screw connection band J is fed in the feed direction (right side in FIG. 1) by one pitch. Go. Accordingly, one screw S is supplied directly below the driver bit 15 when the user pushes down the screw tightening machine body 2 and the feeder box 22 starts to move backward (upward) with respect to the case 21. .
FIG. 7 shows the screw connection band J. The screw connection band J is formed by holding a number of screws S to S in parallel with each other at regular intervals on a belt-like sheet material T having appropriate elasticity, and may have the same configuration as the conventional one. On the both sides of the sheet material T, the notches t to t for pitch feeding are provided at regular intervals. The feed claw 52a of the feed wheel 52 is engaged with the notch t. The full width dimension of the sheet material T is set to W0, and the interval between the notches t, t on both sides in the width direction is set to Wt.
One screw S is supplied directly below the driver bit 15 (coaxial position) by pushing down the screw tightening machine main body 2 in the screw tightening direction with the stopper member 40 abutted against the screw tightening material M. If the screw tightening machine main body 2 is further pushed down as it is, the tip of the driver bit 15 is set on the head of the screw S, and then the screw S is separated from the screw connection band J and is abutted against the screw fastening material M. Thereafter, the screw S is tightened onto the screw fastening material M by rotating the driver bit 15 by starting the electric motor 3. FIG. 2 shows a stage in the middle of this tightening.

The stage where the tightening of the screw S is thus completed is shown in FIG. At this stage, the feeder box 22 has moved to the retracted end (upward moving end) with respect to the case 21. The retracted end position of the feeder box 22 is regulated by a stopper 27. When the feeder box 22 abuts against the stopper 27 from below, the backward end position (stroke) of the feeder box 22 is regulated. The stroke of the feeder box 22 can be adjusted according to the tightening depth (screw length) of the screw S to be tightened. At this stage, the guide roller 51b reaches the vicinity of the upper end of the straight portion 21b of the guide hole 21a.
After the screw tightening is completed and the screw tightening machine body 2 is pushed down to the lower end, when the user releases the push-down operation, the feeder box 22 is biased forward by the compression spring 23. The screwing machine body 2 is relatively returned upward. As a result, the guide roller 51b moves down the linear portion 21b and is finally returned into the inclined portion 21c. When the guide roller 51b is returned from the linear portion 21b into the inclined portion 21c, the operating arm 51a tilts counterclockwise in FIG. However, in this case, since the ratchet mechanism does not mesh, the tilting operation of the operating arm 51a is not transmitted to the drive wheel 51, and the rotation of the drive wheel 51 in the counterclockwise direction shown in the figure is restricted by the ratchet pawl 53. . Therefore, as shown in FIG. 1, even if the feeder box 22 is returned to the forward end and the operating arm 51a tilts counterclockwise, the drive wheel 51 does not rotate in the same direction (counter feed direction) Therefore, the feed wheel 52 does not rotate in the counter feed direction (clockwise direction in FIG. 1).
In this way, the screw feed mechanism 50 feeds the screw connection band J in the feed direction by one pitch in conjunction with the screw tightening operation (pressing operation) of the screw tightening machine main body 2.
Under the feeder box 22, pedestal portions 22a for supporting both side portions of the sheet material T of the screw connection band J from the lower side are provided. The sheet material T of the screw connection band J enters between the pedestal portion 22a and the feed wheel 52. The screw connection band J enters the pedestal portion 22a through the screw connection band entrance 22b provided on the side of the feeder box 22.

The screw connection band J is guided by the screw connection band guide member 30 to the vicinity of the screw connection band entrance 22b of the feeder box 22 while being held in a fixed posture (a state in which the screws S to S are arranged in parallel). The screw connection band guide member 30 of the present embodiment includes a fixed portion 31 fixed to the screw tightening machine main body 2 and a movable portion 33 supported to be rotatable with respect to the fixed portion 31 via a support shaft 32. ing. The movable portion 33 can be folded with respect to the fixed portion 31 by rotating via the support shaft 32. FIG. 4 shows the screw connection band guide member 30 alone. FIG. 4 shows a use state in which the movable portion 33 is opened with respect to the fixed portion 31. The fixed portion 31 guides the range on the front side of the screw connection band J in the feed direction, and the movable portion 33 guides the range on the rear side.
The fixed portion 31 and the movable portion 33 are provided with sheet holding portions 31a, 31a, 33a, and 33a for guiding the screw connection band J, respectively. The sheet holding portions 31a and 31a of the fixed portion 31 and the sheet holding portions 33a and 33a of the movable portion 33 hold both ends of the sheet material T of the screw connection band J and have a U-shaped cross section. The movable portion 33 is provided so as to face each other. In the state shown in the drawing in which the movable part 33 is taken out to the use position with respect to the fixed part 31, one circular arc in which the sheet holding parts 31 a and 31 a of the fixed part 31 and the sheet holding parts 33 a and 33 a of the movable part 33 are continuous. Located along. Therefore, as shown in FIG. 2, the screw connection band J is attached to the screw connection band guide member 30 with the sheet material T held between the sheet holding parts 31a and 31a facing each other and between the sheet holding parts 33a and 33a. Then, the screw connection band J is held in a state of being curved in a semicircular arc shape, and accordingly, a large number of screws S to S are aligned in the radial direction.

As shown in FIG. 5, both sheet holding portions 31a and 31a of the fixing portion 31 are respectively provided with a holding wall portion 31b on the screw shaft side (left side and inner peripheral side in FIG. 5) and a screw head side (FIG. 5). In FIG. 4, the right and outer peripheral engagement wall portions 31c are provided. The gap 31d between the holding wall portions 31b and 31b can pass through the shaft portion of the screw S and is set to a size smaller than the interval Wt between the cutout portions t and t of the sheet material T.
On the other hand, the gap 31e between the engaging wall portions 31c and 31c is set to a size smaller than the entire width W0 of the sheet material T and larger than the interval Wt between the notches t and t. Moreover, the plate | board thickness dimension of both the engagement wall parts 31c and 31c is set smaller than the width dimension of each notch part t of the sheet | seat material T. FIG. By setting the dimensions of the respective parts in this way, the engaging wall portions 31c are respectively inserted into the left and right cutout portions t and t in the width direction of the sheet material T, and the screw connection band J is formed with the gap 31e. A crossing state (a state in which the screw connection band J is pulled out to the case 21 side through a gap 31e between the sheet holding portions 31a and 31a, a state shown in FIG. 3) can be obtained. The screw connection band J can be moved along the reciprocating direction of the feeder box 22 (the direction indicated by the white arrow in FIG. 7) by causing the engaging wall portions 31c and 31c to function as guide rails in the crossing state. Become.
As will be described later, the screw connection band J moves upward along with the backward movement of the feeder box 22, so that the end of the engagement wall portions 31 c, 31 c on the feed direction front end portion 34 side reaches the end portion most. Engagement wall portions 31c are respectively inserted into the close notches t and t. On the contrary, the notch portions t and t of the sheet material T are moved to the front end portions of the engagement wall portions 31c and 31c by moving the screw connection band J downward (case front end side) with the forward movement of the feeder box 22. Deviate from.

As shown in FIGS. 1 to 3, in the present embodiment, the engaging wall portions 31 c and 31 c are provided along a path parallel to the reciprocating direction of the feeder box 22. On the other hand, both the holding wall portions 31b and 31b on the screw shaft side are provided along the curved path. For this reason, the space | interval between engagement wall part 31c, 31c and holding wall part 31b, 31b becomes so large that it becomes a feed direction back side (illustration upper side), and the flexure absorption part 31f of the screw connection belt | band | zone J is provided. ing. The deflection in the feeding direction is absorbed by deflecting the screw coupling band J in the deflection absorbing portion 31f.
Both the sheet holding portions 33a and 33a of the movable portion 33 also have a U-shaped cross section, but the wall portion on the head side of the screw S is abutted with each other to form one bottom wall portion 33c. In the movable portion 33, the head side of the screw S is closed by the bottom wall portion 33c. On the other hand, the gap 33d between the holding wall portions 33b, 33b on the screw shaft side of the screw S can pass through the shaft portion of the screw S as in the case of the fixing portion 31, and is from the full width W0 of the sheet material T. Even small dimensions are set.

Next, as shown in FIGS. 1 to 3, the feeder box 22 is provided with a retreat-side push portion 25 for pushing the screw connection band J in the retreat direction and a forward-side push portion 26 for pushing in the advance direction. ing. The retreat-side pushing portion 25 is provided in a state of protruding to the side on the rear side (lower side in the drawing) in the retreat direction of the screw connection band entrance 22b. The forward side pushing portion 26 is provided in a state of projecting laterally on the rear side in the forward direction (upper side in the drawing) of the screw connection band entrance 22b. The backward side pushing portion 25 and the forward side pushing portion 26 are projected in a range that does not interfere with the engaging wall portions 31c and 31c of the fixing portion 31 when the feeder box 22 is moved.
The screw connection band J enters the screw connection band entrance 22b through the space between the backward side push part 25 and the forward side push part 26. For this reason, the backward side pushing portion 25 is located on the screw shaft side of the screw S, and the forward side pushing portion 26 is located on the head side of the screw S.
The retreating side pushing portion 25 includes two pushing plates 25a and 25a arranged in parallel with each other with an interval for allowing the screws S of the screw coupling band J to pass therethrough. The interval between the push plates 25a and 25a is set smaller than the full width W0 of the sheet material T. For this reason, the screw coupling band J is guided to the screw coupling band entrance 22b in a state where the sheet material T is straddled while the screws S to S are passed between the push plates 25a and 25a. The screw connection band J is fed in the feeding direction while both sides of the sheet T are brought into sliding contact with the push plate 25a.
As will be described later, when the screw connection band J is pushed backward (upward in the drawing) by the backward pushing portion 25 as the feeder box 22 is retracted, it is respectively engaged in the notches t and t of the sheet T. The mating wall portion 31c enters, and then the engagement wall portions 31c and 31c serve as guide rails so that the screw connection band J can move in the backward direction along the gap 31e in a state of crossing the gap 31e.
The forward-side push portion 26 has a bifurcated shape having a recess that allows the head of each screw S to pass through and a pair of left and right sliding contact portions that are in sliding contact with both side portions of the sheet material T. The screw coupling band J positioned in a state of crossing the gap 31e due to the backward movement of the feeder box 22 is pushed forward by the forward pushing portion 26 (downward in the drawing) as the feeder box 22 advances, From the state in which the screw connection band J crosses the gap 31e, the guide state is returned to the state in which the screw connection band J is guided along both the sheet holding portions 31a and 31a of the fixed portion 31.

According to the screw tightening machine 1 including the screw feeding device 20 of the present embodiment configured as described above, the screw tightening machine main body 2 is fixed to the screw tightening material M in a state where the stopper member 40 is abutted against the screw tightening material M. By pushing down to the side, the feeder box 22 relatively retreats (moves upward) in the case 21. Immediately after the feeder box 22 starts to move backward, the screw feed mechanism 50 of the screw feeder 20 feeds the screw coupling band J by one pitch in the screw feed direction, so that one screw S is supplied directly below the driver bit 15. The Thereafter, the screw S is set at the tip of the driver bit 15 by further pushing down the screw tightening machine main body 2. When the driver bit 15 is rotated by starting the motor in this state, the screw S is fastened to the screw fastening material M. It ’s getting crowded. When the tightening of the screw S is completed and the push-down operation of the screw tightening machine main body 2 is released, the feeder box 22 relatively moves forward (downward) in the case 21 by the urging force of the compression spring 23, whereby the screw tightening is performed. As the machine main body 2 moves upward, the screw connection band J fed by the screw feeder 20 has a certain posture (screws S to S aligned in parallel) by the screw connection band guide member 30 to the vicinity of the screw connection band entrance 22b. Guide). The fixing portion 31 of the screw connection band guide member 30 has a gap 31e for pulling the screw connection band J toward the case 21 at a midway position in the guide path and reaching the screw connection band entrance 22b through the shortest path. It is provided along the moving direction.
For this reason, when the feeder box 22 retreats with respect to the case 21 in accordance with the screw tightening operation, the screw connection band J is pushed upward by the retreat-side push portion 25 provided integrally therewith. As shown in FIG. 2, when the sheet material T of the screw connection band J is pushed upward, the distal ends of the engagement holding portions 31 c and 31 c enter the notches t and t of the sheet material T, and the screw The connection band J passes across the gap 31e between the engagement wall portions 31c and 31c, and thereby reaches the screw connection band entrance 22b through a substantially shortest path.
When the screw connection band J is further pushed upward in a state of crossing the gap 31e, the range behind the screw connection band J in the feed direction (the range behind the feed direction relative to the part crossing the gap 31e) is white in FIG. As indicated by the blank arrow, the part is once returned in the reverse feed direction, or the part where it sags is absorbed into the deflection absorbing part 31f.
For this reason, even if the feeder box 22 is retracted upward, it is not folded back at the feed direction tip 34 as in the prior art, but is taken along the gap 31e to the screw connection band entrance 22b through a substantially shortest path. By maintaining the rotated state, the length of the screw connection band J and the number of screws S located in the region between the fixing portion 31 and the feeder box 22 can be maintained almost constant at all times. As a result, the sheet material T and the screws S, S in the area can be avoided from being entangled with each other, and the smooth movement state of the feeder box 22 can be ensured.

After the screw tightening is completed, when the screw tightener main body 2 is returned upward, the feeder box 22 moves forward (downward) with respect to the case 21. At this stage, the screw coupling band J in a state of crossing the gap 31e between the sheet holding portions 31a and 31a is pushed downward by the forward pushing portion 26. As a result, the passage site (crossing position) of the screw connection band J with respect to the gap 31e gradually moves toward the front end 34 in the feed direction. At a stage before the feeder box 22 is returned to the forward end position with respect to the case 21, the engaging wall portions 31 c and 31 c are relative to the cut portions t and t of the sheet material T at the leading end portion 34 in the feeding direction of the fixing portion 31. Thus, the state of crossing the gap 31e of the screw connection band J is restored to the guiding state guided in the feeding direction along the sheet holding portions 31a and 31a.
In this way, at the stage where the screw connection band J is fed by one pitch in the screw feed direction by the screw feed mechanism 50, the screw connection band J is held along the sheet holding portions 31a and 31a of the fixing portion 31. Since the state is restored, as described above, when the feeder box 22 starts to be retracted, that is, at the time of pitch feeding of the screw connection band J, the function of the screw connection band guide member 30 is sufficiently exerted to improve the screw connection band J. Can be ensured.

As described above, when the feeder box 22 moves with respect to the case 21 with the screw tightening operation of the screw tightening machine body 2, the screw connection band J crosses the gap 31e of the screw connection band guide member 30 and is the shortest path. Thus, the state reaches the screw connection band entrance 22b. As a result, the length of the screw connection band J and the number of screws S in the region between the fixed portion 31 and the screw connection band entrance 22b are maintained substantially constant regardless of the position of the feeder box 22 in the moving direction. The
For this reason, even if the feeder box 22 is retracted upward with respect to the case 21, the sheet material T and the screws S, S are not entangled between the fixing portion 31 and the feeder box 22. 22 smooth forward movements can be obtained.
In particular, when the length of the screw S to be tightened is longer, the stroke of the feeder box 22 is larger, and the length of the screw S fed by the screw feeder 20 is longer, and therefore the configuration according to this embodiment is employed. A great effect can be obtained.

The embodiment described above can be implemented with various modifications. For example, it is good also as a structure which abbreviate | omits both the back side pushing part 25 provided in the feeder box 22, or the advancing side pushing member 26, or one. In the case of omitting these, a gap corresponding to the exemplified gap 31e is additionally set with respect to the existing screw connection band guide member without adding a special member or part as compared with the conventional configuration. It is possible to obtain the same operation effect only by the above.
Further, the movable portion 33 provided to be foldable with respect to the fixed portion 31 in the screw connection band guide member 30 may be omitted.

It is a longitudinal section of the whole screw fastening machine provided with a screw feeder concerning an embodiment of the present invention. This figure shows a state in which the screw tightening machine main body is not pushed down, and thus a state in which the feeder box is located at the lower moving end with respect to the case. It is a longitudinal cross-sectional view of the screw feeder which concerns on embodiment of this invention. This figure has shown the state in the middle of the feeder box retreating with respect to a case by pushing-down operation of the screw-fastener main body. It is a longitudinal cross-sectional view of the screw feeder which concerns on embodiment of this invention. This figure has shown the state which the feeder box retracted | retreated to the upper moving end with respect to the case by pushing down operation of the screw-fastener main body. In this state, the screw connection band crosses the gap between the sheet holding portions. It is a perspective view of a screw connection belt guide member. FIG. 5 is a sectional view taken along line (5)-(5) in FIG. 2. In this figure, a state in which the screw connection band crosses between the sheet holding portions in the fixing portion is indicated by a two-dot chain line. FIG. 3 is a sectional view taken along line (6)-(6) in FIG. 2. This figure shows a state in which the screw connection band is held between the sheet holding portions in the movable portion 33. It is a top view of a screw connection belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Screwing machine 2 ... Screwing machine main body 3 ... Electric motor 4 ... Drive gear 5 ... 1st intermediate gear 6 ... 2nd intermediate gear 7 ... Driven gear 8 ... Spindle, 8a ... Flange part 9 ... Meshing clutch 10 ... Compression Spring 11 ... Handle portion 12 ... Main body housing 13 ... Bearing 14 ... Switch lever 15 ... Driver bit 16 ... Battery pack J ... Screw connection band S ... Screw T ... Sheet material, t ... Notch M for pitch feed ... Screw tightening Material 20 ... Screw feeder 21 ... Case, 21a ... Guide hole, 21b ... Linear part, 21c ... Inclined part 22 ... Feeder box, 22a ... Base part, 22b ... Screw connection band entrance 23 ... Compression spring 25 ... Reverse side push Part, 25a ... push plate 26 ... forward side pushing part 27 ... stopper 30 ... screw connection band guide member 31 ... fixing part, 31a ... sheet holding part, 31b ... holding wall part, 31c ... engagement Wall portion 31d ... gap (screw shaft side), 31e ... gap (head side), 31f ... flexion absorbing portion 32 ... support shaft 33 ... movable portion 33a ... sheet holding portion, 33b ... holding wall portion, 33c ... bottom wall portion 33d: Clearance 34 ... Feed direction tip 40 ... Stopper member 50 ... Screw feed mechanism 51 ... Drive wheel 51a ... Actuating arm 51b ... Guide roller 52 ... Feed wheel 52a ... Feed claw 53 ... Ratchet claw

Claims (3)

In conjunction with the screw tightening operation of the screw tightening machine main body, the screw connection band holding a number of screws in parallel with each other on the belt-like sheet material is pitch-fed in the screw feed direction to the spindle of the screw tightening machine main body. A screw feeding device that supplies screws one by one to a mounted driver bit,
A case attached to the screw tightening machine main body with the driver bit inserted into the inner peripheral side, and supported by the case so as to be movable in the axial direction of the screw tightening, and intermittently rotating the ratchet wheel by the moving operation. A feeder box having a ratchet mechanism that pitch-feeds the screw connection band in the screw feed direction, and a screw connection that is supported by the screw tightening machine main body and guides the screw connection band to the screw connection band entrance of the feeder box A belt guide member,
The screw connection band guide member has a sheet holding portion that holds both side portions of the screw connection band on the inner side and holds the screw connection band so as to be movable in the feed direction, facing the left and right in the feed direction,
By moving the screw connection band along the gap in a state of crossing the gap formed between the two sheet holding portions, along with the movement of the screw connection band advance entrance with the backward movement of the feeder box, A screw feeding device configured to be able to hold the length of the screw connection band in a range from the screw connection band guide member to the screw connection band advance entrance regardless of the position in the moving direction of the feeder box. 2. The screw feeding device according to claim 1, wherein the feeder box has a rearward direction in a backward direction with respect to the screw connection band entrance, and between the screw connection band entrance and the screw connection band guide member. A screw feeding device provided with a retreating side pushing portion that pushes the screw connection band in the retreating direction to enter the clearance between the sheet holding portions and moves along the clearance. 3. The screw feeding device according to claim 1, wherein the feeder box has a rear side in a forward direction with respect to the screw connection band entrance, and between the screw connection band entrance and the screw connection band guide member. The screw connection band is pushed in the forward direction, and the screw connection band is provided with a forward side pushing portion that restores the screw connection belt from the state crossing the gap between the sheet holding portions to the state guided along the both sheet holding portions. Screw feeder.

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