JP3090019B2 - Screw guide device of screw tightening machine for connecting screw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw guide device for a connecting screw, and more particularly to a screw guide device for a connecting screw, which opens and closes a screw inlet of a nose portion by a shutter lever. It is about.

[0002]

2. Description of the Related Art In a power screw tightening machine using a connecting screw in which a number of screws are connected in parallel by a plastic belt or the like, generally, a screw supplied into a nose portion cannot be visually recognized. When screwing a building material such as a slate roof that has a screw insertion hole in advance, it is difficult to match the screw with the screw insertion hole unless the screw tip is exposed. There has been proposed a screw tightening machine configured so that a screw protrudes from a screw.

[0003] In this screw tightening machine, one side of a screw chuck at the end of a nose block of the screw tightening machine is opened to provide a screw introduction port, and the body of a connection-type screw is inserted into the screw chuck so that the tip of the screw is tightened. This is a structure in which the portion protrudes from the screw chuck. However, if the screw inlet is always open, the tip of the screw may come into contact with a building material or the like and fall out of the screw inlet to prevent the screw from being screwed. In order to prevent the screw from being inclined, a screw guide device that opens and closes a screw inlet of a screw chuck has been proposed (Japanese Patent Application No. 7-120).
No. 580).

FIG. 8 shows a nose portion of a screw tightening machine provided with the above-mentioned guide device, 1 is a nose holder fixed to the screw tightening machine main body, 2 is a nose block which is slidably inserted into the nose holder, and 3 Denotes a pair of left and right screw chucks, and 4 denotes a driver bit.

[0005] A compression coil spring 5 is interposed between the nose block 2 and the main body housing, and the nose block 2 is urged in a direction to extend from the nose holder 1. A shutter lever 6 for opening and closing the screw inlet 3a on the lower surface of the screw chuck 3 is pivotally mounted on the front surface of the nose block 2. The front end of a lever 7 pivotally mounted inside the nose block 2 projects from the front surface of the nose block 2. And is engaged with the lower end of the shutter lever 6.

On the inner wall surface of the nose holder 1, there are two levels of cam surfaces 1a, 1a parallel to the sliding direction of the nose holder 2.
The guide roller 9 at the rear end of the lever 7 is pressed against the cam surface 1a by the urging of the compression coil spring 8.

The shutter lever 6 is urged by a spring (not shown) in a direction to retreat from the lower surface of the screw chuck 3 (counterclockwise in FIG. 2B), but in an initial state shown in FIG. 7, the screw chuck 3 is turned to a position where the screw inlet 3a on the lower surface of the screw chuck 3 is closed.

When the nose block 2 is slid in the contracting direction from the state shown in FIG. 1, the guide roller 9 of the lever 7 rolls along the lower cam surface 1a, and when it rides on the higher cam surface 1b, the lever 7 Is rotated outward from the position shown in FIG. In conjunction with this, the shutter lever 6 rotates counterclockwise, and the screw inlet 3a of the screw chuck 3 is opened.

When the screwing machine is separated from the wall surface after screwing, the nose block 2 extends, and although not shown,
The ratchet wheel with a ratchet for screw feeding provided in the nose block 2 rotates by a fixed angle via a link, and the connecting band B of the connecting screw BS engaged with the ratchet wheel is shown in FIG. The next screw S is fed into the screw chuck 3 by feeding a certain distance from the bottom to the top, and at the same time, the lever 7 and the shutter lever 6 rotate in the direction opposite to the contraction stroke, and the shutter lever 6 Return to the closed position shown.

The opening / closing timing of the shutter lever 6 is such that in the contraction stroke of the nose block 2, the closed state of the shutter lever 6 is maintained until the screw is screwed into the object to some extent to prevent the screw from falling down, and then the opening lever is turned in the opening direction. It is necessary to start the operation and retract from the path of the driver bit 4.

However, the illustrated cam mechanism has a cam surface 1 so as to further delay the opening start timing of the shutter lever 6 during the contraction stroke of the nose block 2.
When the switching positions of a and 1b are set, the timing of the closing start is advanced earlier in the extension stroke, so that the screw to be supplied into the screw chuck 3 next completely enters the screw inlet 3a. Before the shutter is inserted, the shutter lever 6 may be closed to cause a supply failure. Therefore, there is a limit to delaying the timing of starting the opening of the shutter lever 6, and the screw may fall down because the shutter lever is opened at the initial stage of screw tightening.

[0012] Then, there arises a technical problem to be solved in order to prevent the screw tightening failure due to the falling of the screw, and an object of the present invention is to solve the above problem.

[0013]

SUMMARY OF THE INVENTION The present invention, which is proposed to achieve the above object, is a screw tightening machine using connection type screws inserted at regular intervals in the longitudinal direction of a connection band. A nose block is slidably mounted in the nose holder of the screw tightening machine in a screw screwing direction in a predetermined range, and the nose block is urged in a direction of extension by a spring, and a hook wheel for feeding a connecting screw is connected to the nose block. A ratchet feed mechanism is interposed between the ratchet wheel and the nose holder to constitute a screw feed mechanism that rotates the ratchet wheel at a constant angle in one direction when the nose block is extended, and is attached to the tip of the nose block and the nose block. A screw introduction opening is formed by opening one surface of the screw chuck, and the body of the connection type screw is formed so as to be introduced into the screw chuck. A shutter mechanism that opens and closes a screw introduction port of the screw, a cam mechanism is interposed between the shutter lever and the nose holder, and the shutter lever is driven by the screw introduction port of the screw chuck in conjunction with the contraction and extension of the nose block. In the screw tightening machine for a connecting screw provided with a screw guide device for opening and closing, a parallelogram loop-shaped cam groove is provided on a side surface of the nose holder, and a nose block is provided at an intermediate portion of a shutter lever for opening and closing the screw introduction port. The rear end of the shutter lever circulates in one direction along the loop-shaped cam groove when the nose block expands and contracts, by axially attaching the shutter lever to the cam groove. And the loop shape and the circulating direction of the cam groove are respectively set in the contraction stroke and the extension stroke of the nose block. Wherein in extent of late shutter lever is to provide a screw guide device of the connecting screw screwing, characterized in that the set to start rotating.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show a screw guide device, in which a nose holder 11 is fixed to a mechanism housing with a grip of a screw tightener for connecting screws. Nose holder 1
A nose block 12 is freely slidably fitted in 1,
At the tip of the nose block 12, a screw chuck 13 divided into two parts on the left and right is pivotally mounted. The driver bit 14 disposed in the nose holder 11 is connected to a rotation drive mechanism by an electric motor of a mechanism housing (not shown). A compression coil spring (not shown) is interposed between the mechanism housing and the nose block 12 so that the nose block 1
2 is urged in a direction extending from the nose holder 11.

Nose block 12 and screw chuck 1
3, screw introduction ports 12a and 13a are opened on the lower surface, and the screw guide path 12b of the nose block 12 crosses the path of the driver bit 14 in the vertical direction. Screw chuck 13
Is urged in the closing direction by a spring (not shown), but is expanded right and left by a screw head that travels inside the screw chuck 13 when tightening the screw.

A shutter lever 15 is pivotally mounted on the side surface of the nose block 12 at the front and rear intermediate portion.
The guide roller 16 mounted on the side surface of the rear end portion is engaged with a cam groove 17 formed on the side surface of the nose holder 11.
The shutter lever 15 is urged by a torsion coil spring (not shown) in a direction (clockwise in FIG. 1) to open the screw introduction port 13a of the screw chuck 13, but in the initial state shown in FIG. It is in a position to close the mouth 13a.

As shown in the figure, the cam groove 17 is a parallelogram loop, and the guide roller 16 circulates in the cam groove 17 along a clockwise path in the figure. A one-way shutter lever 18 is pivotally attached to the front of the nose holder 11, the front oblique side 17 d of the cam groove 17 is closed by the tip of the one-way shutter lever 18, and the guide roller 16 is initialized when the nose block 12 is contracted. It is guided from the position to the bottom 17a of the cam groove.

When the nose block 12 is slid in the contracting direction, the guide roller 16 of the shutter lever 15 moves rearward along the bottom side 17a of the cam groove, rises along the rear oblique side 17b at the middle part, and rises at the upper side 17c. Proceed to the rear end site. And the return route moves forward along the upper side 17c,
It descends along the front oblique side 17d and presses the back of the one-way shutter lever 18 so that the one-way shutter lever 1
8 is withdrawn from the route and returns to the initial position. The shutter lever 15 reciprocates and rotates following the expansion and contraction of the nose block 12, and opens and closes the screw introduction port 13 a of the screw chuck 13.

FIGS. 3 to 5 show a screw feeder, in which pawls of a ratchet-equipped ratchet wheel 19 rotatably supported by a nose block 12 are provided at regular intervals on a plastic belt B of connection type screws BS shown in FIG. Engage with the notch n and connect the screw B
Send S from below to above.

The ratchet wheel with ratchet 19 has a known configuration, in which a feed pawl is formed on the outer peripheral surface, and ratchet pawls are radially arranged on the side surface at a constant angle. A disk 20 having holes radially pierced symmetrically with the ratchet pawl is loosely fitted coaxially, and the disk 20 is pressed against the side surface of the ratchet wheel 19 by the bias of a spring (not shown).

One end of a link 21 is pivotally connected to the disk 20, and a guide roller 22 at the other end of the link 21 is engaged with a guide groove 11 a provided in the nose holder 11 and parallel to the sliding direction of the nose block 12. I have.

A lever 23 is pivotally mounted near the front lower end of the nose holder 11, and a hook 23a projecting sideways is provided at the upper and lower middle part of the lever 23. The hook portion 23a is engaged with a hole 11b formed in the side plate of the nose holder 11, and the rotation range of the lever 23 is as follows.
The hole 11b limits the angle from a substantially vertical standing state to a certain angle only forward (in the direction of the nose block). The lever 23 is urged in a rising direction by a spring (not shown), and the rear surface of the upper end portion is in pressure contact with the front surface of the guide roller 22 of the link 21 in the initial state.

In the middle of the nose block 12, the lever 2 is located in the middle of the extension of the nose block 12.
A stopper 12c for restricting the movement of No. 3 is formed.
The stopper 12 c is a bent portion having a height located on the lower surface of the hook portion 23 a of the lever 23 in the upright state, and is provided in parallel with the sliding direction of the nose block 12.

Next, the operation of the screw guide device will be described. The operation timing of the shutter lever 15 and the ratchet ratchet 19 is shown in the timing chart of FIG. First, the nose block 1 in the initial state shown in FIGS.
Numeral 2 is in the extended position by the bias of the compression spring, and the lever 23 of the feed device is pressed forward by the guide roller 22 of the link 21 and tilts forward. The driver bit 14 is started by pressing the screw S (the screw thread is omitted in the figure) held by the screw chuck 13 against the object, the screw tightening progresses, the nose block 12 is pushed in, and the shutter lever 15 is pushed. When the guide roller 16 reaches the rear oblique side 17b of the cam groove, the shutter lever 15 starts rotating in the opening direction (A in FIG. 7).

Immediately before the end of the contraction stroke, the shutter lever reaches the upper side 17c of the cam groove (B in FIG. 7) and stops at the open position as shown in FIG. Stopper 24 provided on
Is temporarily stopped from retreating and the ratchet wheel with ratchet 19
4, the disc 20 is pressed through the link 21 and rotates counterclockwise. As shown in FIG. 4, at the end of the screw tightening, the ratchet pawl of the ratchet wheel 19 with a ratchet rides over and engages with the next ratchet pawl. (C in FIG. 7).

After the screw tightening is completed, the screw tightening machine is lifted from the object, and when the nose block 12 enters the extension stroke by the bias of the compression spring, the guide roller 16 of the shutter lever 15 moves along the upper side 17c of the cam groove. Move forward,
The shutter lever 15 maintains the open state, and the lever 23 of the screw feeder is connected to the guide roller 2 of the link 21.
7 (D in FIG. 7), and the lever 23 is pressed forward, but as shown in FIG. 5, the hook portion 23a abuts the stopper 12c of the nose block 12 and is prevented from rotating forward. You. As a result, the link 21 is pulled backward through the guide roller 22 which is in contact with the back surface of the lever 23, and the disk 20 rotates clockwise to rotate the ratchet wheel 1
The interlocking screw 9 is engaged and the connecting screw engaged with the ratchet of the ratchet ratchet 19 is fed.

After the state shown in FIG.
The hook portion 23a passes through the position of the stopper 12c and the engagement between the lever 23 and the stopper 12c is released (E in FIG. 7), and the lever 23 is pressed by the guide roller 22 and tilts forward, and the disk 20 and the ratchet The rotation of the ratchet wheel 19 is released. At substantially the same time, the guide roller 16 of the shutter lever 15 reaches the front oblique side 17d of the cam groove, and the shutter lever 15 starts rotating in the closing direction.

Subsequently, just before returning to the standby position shown in FIGS. 1 and 3, the guide roller 22 of the feeder is pulled in contact with the front edge of the guide groove 11a (F in FIG. 7), and the shutter lever is moved. 15 of the guide roller 16 is the bottom 17a of the cam groove.
, The shutter lever 15 closes the screw inlet 13a of the screw chuck 13 (G in FIG. 7), and the disk 20 and ratchet wheel 19 stop at the specified positions (H in FIG. 7).

As shown in FIG. 7, at the time E when the shutter lever 15 enters the closing stroke in the extension stroke after the screw tightening is completed, the screw feeding by the ratchet wheel 19 with the ratchet is almost finished. Therefore, even if the posture of the screw S sent to the screw introduction port 13a is inclined and the advance of the body is delayed with respect to the head, the shutter lever 15 reliably introduces the body of the screw into the screw chuck 13. can do.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope of the present invention. is there.

[0031]

As described above, the screw guide device of the connecting screw screw tightening machine according to the present invention minimizes the timing of starting the rotation of the shutter lever in each of the contraction stroke and the extension stroke of the nose block. Since the screw is configured to be delayed, at the time of screw tightening, the screw is held by the screw chuck and the shutter lever until the screw is screwed to some extent and the posture is stabilized, so that the screw can be prevented from tipping over.

In the extension step of the nose block after the screw is tightened, the shutter lever starts rotating in the closing direction after the screw feed is almost completed, so that the screw to be supplied into the screw chuck next is completely screwed. The shutter lever is not closed before being inserted into the introduction port, and the possibility of screw supply failure is eliminated.

Unlike the conventional shutter lever which is opened and closed via a cam and a lever, the shutter lever is directly opened and closed by the cam, so that the operating load of the shutter lever is reduced and the nose block is pushed in when the screw is tightened. There is also an effect that the load is reduced and workability is improved.

[Brief description of the drawings]

FIG. 1 shows a screw guide device according to an embodiment of the present invention, and is a partially cutaway side view of a nose portion of a screw tightening machine for connecting screws.

FIG. 2 is a partially cutaway side view showing an operation state of the screw guide device shown in FIG. 1;

FIG. 3 is a partially cutaway side view of a nose part showing the screw feeder.

FIG. 4 is a partially cutaway side view showing an operation state of the screw feeder shown in FIG. 3;

FIG. 5 is a partially cutaway side view showing an operation state of the screw feeder shown in FIG. 3;

6A and 6B show connection type screws, wherein FIG. 6A is a plan view and FIG. 6B is a side view.

FIG. 7 is a timing chart of a shutter lever and a ratchet with ratchet.

8A and 8B show a conventional screw guide device, in which FIG. 8A is a plan sectional view of a nose portion, and FIG. 8B is a front view.

[Explanation of symbols]

 11 Nose Holder 11a Guide Groove 11b Hole 12 Nose Block 12a Screw Inlet 12b Screw Guideway 12c Stopper 13 Screw Chuck 13a Screw Inlet 14 Driver Bit 15 Shutter Lever 16 Guide Roller 17 Cam Groove 18 One-Way Shutter Lever 19 Ratchet Wheel

Claims (1)

(57) [Claims] 1. A screw tightening machine using connection type screws which are inserted at regular intervals in a longitudinal direction of a connecting band, wherein a nose block is slidable in a nose holder of the screw tightening machine in a screw screwing direction in a fixed range. The nose block is attached and urged in the extension direction by a spring, and a hook for feeding a connecting screw is provided on the nose block, and a ratchet feed mechanism is interposed between the hook and the nose holder to extend the nose block. Sometimes, a screw feed mechanism for rotating the ratchet wheel at a constant angle in one direction is formed, and one surface of the nose block and a screw chuck mounted on the tip of the nose block are opened to form a screw introduction port, and a body of a connection type screw is formed. And a shutter lever for opening and closing a screw introduction port of the screw chuck. A screw mechanism for a connecting screw provided with a cam mechanism interposed between the screw holder and a screw guide device for opening and closing a screw introduction port of the screw chuck by the shutter lever in conjunction with a contraction and extension operation of the nose block. , A parallelogram loop-shaped cam groove (17) is provided on a side surface of the nose holder (11), and an intermediate portion of a shutter lever (15) for opening and closing the screw introduction port (13a) is provided on a side surface of the nose block (12). And the rear end of the shutter lever is engaged with the cam groove so that the rear end of the shutter lever circulates in one direction along the loop-shaped cam groove when the nose block expands and contracts. And the loop shape and the circulating direction of the cam groove (17) are set at the end of the stroke in each of the contraction stroke and the extension stroke of the nose block (12). Shutter lever (15) is threaded guide device of the screw tightener for the connecting screw, characterized in that the set to start rotating.