JP2005169512A - Automatic thread fastening device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic thread fastening device capable of fastening a screw into a narrow part. <P>SOLUTION: This automatic thread fastening device is provided with a bit located on an axis of a catcher part 10 holding screws separately one by one. The catcher part 10 has a pair of holding claw bodies 15, 15 provided facing each other laterally at a front end 3a of a supply chute 3 so as to freely approach/separate; spring means 24, 24 energizing both holding claw bodies 15, 15 to approach each other; and a locking means 25 for stopping both holding claw bodies 15, 15 in fixed positions with a space slightly larger than the shank diameter of the screw, against the spring means 24. When the lowered bit is engaged with the head of the screw held between both holding claw bodies 15, 15 to pressurize with predetermined pressure, both holding claw bodies 15, 15 are spaced against the spring means 24 through the head, and the bit passes through between both holding claw bodies 15, 15 to fasten the screw to a fastened member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention separates the screws one by one at the front end of the supply chute that conveys the screws supplied from the screw supply unit in a suspended state, and is positioned on the axis of the catcher unit. The present invention relates to an automatic screw fastening device in which the screw is fastened by a bit.

  Conventionally, as this type of automatic screw fastening device, for example, those disclosed in Patent Document 1, Patent Document 2, and the like are known.

In the above conventional screw tightening device, the catcher portion holding the screw and the bit descend together, and after the tip of the screw comes into contact with or close to the object to be fastened, the catcher portion opens and the screw is tightened by the bit. ing. For this reason, for example, when a screw is fastened to a narrow part such as the groove bottom of a C-shaped steel, the catcher part does not enter, or even if it enters, there is no space for opening the catcher part, so it cannot be used was there.
JP 57-54039 A U.S. Pat. No. 2,989,996

  The present invention has been made in view of the above-described conventional problems, and provides an automatic screw tightening device capable of screw tightening if there is a gap through which a screw head can pass even in a confined narrow portion. The purpose is that.

  In order to achieve the above-mentioned object, the present invention provides a supply chute for aligning and conveying screws, a catcher portion for separating and holding the screws one by one at the front end of the supply chute, and an axis of the catcher portion. An automatic screw fastening device comprising: a bit positioned at a position; a rotation drive unit that rotationally drives the bit; and an elevating unit that raises and lowers the rotation drive unit, wherein the catcher unit is provided at a front end portion of the supply chute A pair of holding claws that are opposed to each other in the lateral direction and are provided so as to be capable of approaching and separating, spring means for biasing the two holding claws so as to approach each other, and the two holding claws for the spring means And a locking means for stopping at a fixed position separated by a distance slightly larger than the shaft diameter of the screw. Held in between When the heads of the screws are engaged and pressurized with a predetermined pressure, the two holding claws are separated from each other against the spring means via the heads, and the bit is moved together with the screws. It is configured to pass between the holding claws and fasten the screw to the fastened member.

  In the above configuration, the lowering bit is correctly engaged with the engaging hole of the rotating tool provided in the head of the screw held between the two holding claws, and the tip end portion of the bit is In order to fit into the engagement holes, the present invention includes a recess for accommodating and holding the head of the screw pressurized by the bit at the upper part of the opposing surface of the holding claws, and a lower end of the recess And an inclined guide groove that extends obliquely to the facing surface and separates the holding claws through the head of the screw pressurized by the bit.

  With this configuration, when the bit is lowered and the screw is pushed down and the head is accommodated and held in the recess, a braking action is exerted on the head, so the bit rotates relatively. By descending, the position difference between the tip of the bit and the engagement hole is eliminated, and the tip of the bit is correctly engaged with the engagement hole and securely fitted. In this state, when the bit further descends and pushes down the screw, the outer peripheral surface of the head engages and moves in the inclined guide groove, and the both holding claws are moved against the spring means. It can be gradually expanded and separated. Since the outer peripheral surface of the head of the screw is usually formed in a circular shape, it is preferable that the concave portion is a semicircular arc concave portion and the inclined guide groove is a conical concave groove.

  In order to pressurize the head of the screw by lowering the bit and smoothly receive and hold the screw in the recess, an upwardly extending guide inclined surface for guiding and guiding the head is provided at the upper end of the recess. Preferably it is.

  Furthermore, in order to position and hold the screw supplied between the two holding claws at a predetermined position, a stopper for contacting and positioning the screw head is provided.

  Specifically, the locking means includes a pressing spring that is fitted into a mounting member that slidably supports the holding claws so as to face the side surfaces of the holding claws, and the pressing springs. A spherical body that is urged so as to be pressed against the side surface of each holding claw body, and a positioning locking recess that engages with the spherical body that is provided on the side surface of each holding claw body.

  As described above, the automatic screw tightening device of the present invention has an advantage that even a confined narrow part can be screwed if there is a gap through which the screw head can pass.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an automatic screw tightening device 1 according to the invention. The automatic screw tightening device 1 includes a supply chute 3 attached to a frame 2 and an electric rotary tool 4 with a driver bit that is assembled to the front surface of the frame 2 so as to be movable up and down. The electric rotary tool 4 is a general-purpose tool and will not be described in detail. However, when a fixed thrust (usually about 2 kgf to 3 kgf) is applied to the attached driver bit 5, a rotational force is applied to the bit 1. It has a structure to do.

  The electric rotary tool 4 is attached to a movable base 7 that is slidable in a vertical direction along a guide column 6 standing on the front surface of the frame 2, and the movable base 7 is moved up and down by an air cylinder 8 attached to the frame 2. Thus, the electric rotary tool 4 can be moved up and down.

  The supply chute 3 is connected to a screw supply unit (not shown) such as a parts feeder with its front end inclined downward, and the supplied screw (in the example shown, a drill screw) 40 hangs its head 41 from the neck. In the state posture, it is a structure that is slid by its own weight and continuously conveyed, and a guide body 9 is provided along the upper portion of the supply chute 3 to prevent the screw 40 from dropping off due to popping out. Further, the front end portion 3a of the supply chute 3 extends in the horizontal direction so that the screw 40 is conveyed in a vertical posture, and a catcher portion that separates and holds the screws 40 one by one at the chute front end portion 3a. 10 is provided.

  As shown in FIGS. 2 to 4, the catcher unit 10 includes two mounting members 11 and 12 that are fixed to the chute front end portion 3 a by a set bolt 14 via a pressing plate 13, and both the mounting members 11 and 12. A pair of holding claws 15 and 15 that are opposed to each other in the transverse direction perpendicular to the conveying direction of the screw 40 and are slidably assembled are provided. The driver bit 5 is arranged on the axis of the screw holding position between the holding claws 15 and 15.

  As shown well in FIG. 5, the holding claw 15 is formed in a short rectangular parallelepiped, and includes a recess 17 that holds and holds the screw head 41 on the upper portion of the facing surface 16, and a lower end of the recess 17. And an inclined guide groove 18 extending in an inclined manner to the opposing surface. Since the head 41 of the screw 40 is usually formed with a circular outer peripheral surface, the concave portion 17 is an arc-shaped concave portion, and the inclined guide groove 18 is a conical concave groove. Further, an upwardly extending guide inclined surface 19 that guides and guides the head 41 of the screw 40 is chamfered at the upper end of the recess 17. On the other hand, a spring accommodation hole 20 that opens toward the back surface of the holding claw body 15, that is, the wall surface opposite to the facing surface 16 and extends toward the facing surface 16 is provided. Further, on one side wall surface of the holding claw body 15, a guide ridge piece 21 that projects and slides by engaging with a guide groove 23 provided on the side wall of the mounting member 11 is provided. On the side wall surface on the opposite side of the piece 21, there is provided a locking recess 22 in which a sphere 27 of a positioning locking portion 25 described later is engaged.

  As shown in FIGS. 2 and 3, the two holding claws 15, 15 are arranged such that the guide protrusions 21, 21 are engaged with the guide grooves 23 of the mounting member 11 and the opposing surfaces 16, 16 face each other. Then, it is slidably assembled between the mounting members 11 and 12 and is urged so as to approach each other by the push springs 24 and 24 fitted in the spring accommodating holes 20 and 20. Ends of the pressing springs 24, 24 are supported by the pressing plate 13. In addition, the holding member 15 is fixed to one attachment member 12 at a distance slightly larger than the outer diameter of the screw shaft portion 42 of the screw 40 against the spring pressure of the push springs 24, 24. Locking portions 25, 25 that stop and hold at positions are provided. The locking portion 25 is provided penetrating the mounting member 12 and has mounting holes 26, 26 that open to the side wall surface where the locking recesses 22, 22 of the holding claws 15, 15 are provided, and the mounting holes 26, Spheres 27, 27 that are inserted into 26 and engage with the locking recesses 22, 22, and are fitted into the mounting holes 26, 26 to press the spheres 27, 27 against the locking recesses 21, 21. The pressing springs 28 and 28 are configured by a pressing plate 29 that supports the end portions of the pressing springs 28 and 28. The holding plate 29 is fixed to the mounting member 12 with a set bolt 30.

  In the above configuration, the spring pressure of the pressing spring 24 is a predetermined pressure (about 3 kgf or more) by engaging the head 41 of the screw 40 held between the holding claws 15 and 15 when the driver bit 5 is lowered. When the pressure is applied, the retaining recesses 22 and 22 are set to be detached from the spheres 27 and 27 by the lateral component force so that the two holding claws 15 and 15 can be separated from each other via the head 41. Has been.

  Further, a stopper 31 is provided at the center of the upper surface of the attachment member 12. The stopper 31 abuts against the head 41 of the screw 40 supplied and held between the holding claws 15, 15 to position the screw 40 at a predetermined position. It is being fixed to the attachment member 12 with the volt | bolt 33 so that position adjustment is possible.

  6 and 7 show a fitting process and a screwing process of the driver bit 5 and the screw 40 by the automatic screwing device 1 of the present invention configured as described above. FIG. 6A shows that the screw 40 conveyed by the supply chute 3 is positioned by the stopper 31 and held between the holding claws 15, 15, and the pointed portion 5 a of the lowered bit 5 is the head of the screw 40. In this state, the bit 5 is not driven to rotate, and the tip 5a is correctly inserted into the engaging hole 43 of the rotating tool provided in the head 41. Since they are not necessarily engaged, they may be displaced in the circumferential direction. In this state, when the bit 5 further descends and pressurizes the head 41 to push down the screw 40, the head 41 resists the push springs 24, 24 as shown in FIG. 15 and 15 are separated from each other and are accommodated and held in the concave portions 17 and 17, and a braking action is applied to the head 41. On the other hand, since the bit 5 is rotationally driven in conjunction with the applied pressure accompanying the lowering of the bit 5, the misalignment between the tip 5a and the engagement hole 43 is eliminated, and the tip 5a of the bit 5 is engaged with the engagement hole. 43 is correctly engaged with the screw head 41. Subsequently, when the bit 5 is rotated and further lowered and the screw 40 is pushed down, the outer peripheral surface of the head 41 engages with the inclined guide grooves 18 and 18 and moves downward. 15 is further separated from the pressing springs 24, 24, and as shown in FIG. 6C, the screw 40 fitted to the bit 5 and the tip 5a is held by the head 41 with both holding claws 15, 15 Is passed between both holding claws 15, 15 so as to expand.

  The bit 5 that has passed between the holding claws 15 and 15 and the screw 40 fitted to the pointed end 5a descend at a high speed while rotating, and the drill portion 44 at the tip of the screw 40 is attached to the fastened members 50 and 51. In contact with each other, a screw pilot hole is processed by the drill portion 44, and the screw shaft portion 42 is screwed into the fastened members 50 and 51 to fasten both the members 50 and 51. In this screw tightening step, the bit 5 descends at a high speed, so that the screw 40 fitted to the tip 5a does not fall off the bit 5 before coming into contact with the fastened member 50.

  When the screw tightening operation is completed and the driver bit 5 is detached from the screw 40 and rises to the standby position, the holding claws 15 and 15 are again pushed back to a predetermined position close to each other by the push springs 24 and 24, and the next screw 40 is supplied and held between the holding claws 15 and 15. Thereafter, the screw 40 can be efficiently screwed by the same work sequence as described above.

  The automatic screw tightening device according to the present invention is suitable for screwing a drill screw into a narrow groove bottom of a C-shaped steel constituting a steel house structure, for example, a short drill screw having a short screw shaft portion. Suitable for automatic screw tightening.

It is a side view of the automatic screw fastening apparatus concerning the present invention. It is a top view of a carrier part same as the above. It is sectional drawing which follows the 3-3 line of FIG. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is a perspective view of a holding nail body same as the above. It is explanatory drawing which shows the fitting process of a bit and a screw by the automatic screw fastening apparatus of this invention, (a) hold | maintains a screw between both holding claws, and the pointed part of the descended bit contacts a screw head. (B) is a cross-sectional view of the main part showing a state where the bit presses the screw and the screw head is housed and held in the recesses of both holding claws, and (c) is the bit It is principal part sectional drawing which shows the state which the screw fitted to the tip part passes between both holding claws. It is principal part sectional drawing which shows the screwing process by a bit same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic screw fastening apparatus 2 Frame 3 Supply chute 3a Chute front end part 4 Electric rotary tool 5 Driver bit 7 Movable base 8 Air cylinder 10 Catcher part 11, 12 Attachment member 15,15 Guide groove 19 Guide inclined surface 20 Spring receiving hole 21 Guide protrusion strip 22 Locking recess 23 Guide groove 24 Push spring 25 Locking portion 26 Mounting hole 27 Sphere 28 Push spring 31 Stopper 40 Screw 41 Head portion 42 Screw shaft portion 43 times Engagement hole of moving tool 44 Drill part 50, 51 Fastened member

Claims (6)

A supply chute that aligns and conveys the screws, a catcher part that separates and holds the screws one by one at the front end of the supply chute, a bit that is positioned on the axis of the catcher part, and a rotational drive of the bit An automatic screw tightening device comprising a rotation drive unit and an elevating unit for raising and lowering the rotation drive unit,
The catcher part is
A pair of holding claws that are laterally opposed to each other at the front end portion of the supply chute and are provided so as to be close to each other
Spring means for biasing the holding claws so as to approach each other;
Locking means for stopping the holding claws at a fixed position spaced apart slightly from the shaft diameter of the screw against the spring means;
When the bit lowered by operating by the elevating part engages with the head of the screw supplied and held between the two holding claws and pressurizes with a predetermined pressure, The two holding claws are separated from each other against the spring means, and the bit passes between the two holding claws together with the screw so that the screw is fastened to the fastening member. An automatic screw fastening device characterized by that.   A concave portion for accommodating and gripping the head of the screw pressed by the bit at an upper portion of the opposing surfaces of the two holding claws, and extending obliquely to the opposing surface continuously from the lower end of the concave portion; 2. The automatic screw tightening device according to claim 1, further comprising an inclined guide groove for separating the two holding claws through the head of the screw pressurized by the bit.   The automatic screw tightening device according to claim 2, wherein an upwardly extending guide inclined surface for guiding and guiding the head of the screw is provided at an upper end of the recess.   The automatic screw tightening device according to claim 1, 2 or 3, further comprising a stopper for positioning the screw at a predetermined position by contacting a head of the screw supplied between the holding claws.   A pressing spring in which the locking means is inserted into an attachment member that slidably supports the holding claws so as to face the side surfaces of the holding claws, and the holding claws are formed by the pressing springs. 5. A spherical body that is urged so as to be pressed against the side surface of each of the holding claws, and a positioning locking recess that is provided on a side surface of each of the holding claws and engages with the spherical body. Automatic screw tightening device.   The automatic screw tightening device according to any one of claims 1 to 5, wherein the rotation driving unit is a general-purpose electric rotary tool.

Images