JP4647710B1 - Driver bit - Google Patents

Abstract

Provided is a screwdriver bit that can be surely loosened and removed even when not only an operation groove but also a corner of a base end portion of a sector wall is completely destroyed or deformed.
A driver bit 3 according to the present invention includes five or more rib-like protrusions 11 that are radially projected toward a lower outer side of a bit body 8 and between adjacent rib-like protrusions 11. And a tightening operation section 10 including a trough groove 12 formed in Each rib-like protrusion 11 is composed of a rib peripheral surface 13 formed in the shape of a vertical cylindrical outer surface, and a pair of trough groove peripheral surfaces 14 and 14 sandwiching the rib peripheral surface 13 therebetween. A biting portion 20 that is driven into the peripheral wall 7 of the damaged recess 6 is formed at the corner portion of the lower outer edge of each rib-shaped projection 11 defined by the lower end surface of the rib-shaped projection 11 and the rib peripheral surface 13.
[Selection] Figure 1

Description

  The present invention relates to a driver bit suitable for removing a screw even when an operation groove (plus groove) for tightening and loosening provided on a screw head is broken or deformed.

  If the screw shaft or head of a screw gets rusted, it will be difficult to loosen the screw by applying a screwdriver to a plus groove for tightening operation (hereinafter referred to as an operation groove) provided on the screw head. In that case, the screw can be loosened and removed by using an electric screwdriver with a large tightening torque. However, in many cases, the fan-shaped peripheral wall (hereinafter referred to as the fan-shaped wall) forming the operation groove is shaved with a driver bit, and it is likely that the screw is more difficult to remove due to destruction or deformation of the fan-shaped wall.

  The phenomenon that the fan-shaped wall is scraped with a driver bit is due to the structure of the operation groove on the screw side. Since the operation groove is tapered toward the thread groove side, when the screw is tightened, the cross section of the driver bit has an operation reaction in the direction of floating away from the operation groove. Force acts. For this reason, the cross shaft portion and the operation groove are easily lifted apart, and the fan-shaped wall is shaved when the screw is tightened and loosened in a state of being lifted apart. In order to avoid the state in which the cross shaft portion and the operation groove are separated from each other as described above, various proposals have conventionally been made regarding the structure of the cross shaft portion of the driver bit.

  For example, in Patent Document 1, a pair of ridges are formed in the axial direction along an adjacent slope of a valley groove having a V-shaped cross section formed in the cross shaft portion, and these ridges bite into the fan-shaped wall of the screw head. To prevent lifting from the operation groove. In Patent Document 2, a plurality of concave grooves are formed in the circumferential direction on a partial conical surface (inclined rib circumferential surface) formed on the surface of the cross shaft portion, so that the edge of the cross shaft portion is bitten into the fan-shaped wall. To prevent lifting from the operation groove.

  In the driver bit according to Patent Document 3 previously proposed by the present applicant, the rib-shaped protrusion that forms the cross shaft portion is formed between the rib peripheral surface and the rib peripheral surface that are tapered toward the tip. It is composed of a peripheral surface of a pair of trough grooves sandwiched between, and the ridge where the trough groove peripheral surface on the side that hits the fan-shaped wall of the screw and the rib peripheral surface intersect is set to the loose side edge, and is orthogonal to the projection central axis of the rib-shaped projection However, a rib peripheral surface is formed on the inner side of a virtual plane passing through the loose side edge. Then, in the state where the cross groove portion is engaged with the operation groove of the screw, the rib peripheral surface is prevented from interfering with the radially outer end surface of the operation groove, and the middle part in the vertical direction of the loose side edge is each fan-shaped wall. By securely engaging with the base end corner portion, the torque of the driver bit is transmitted to the sector wall through the loose side edge so that the screw can be surely loosened and removed.

JP 2000-042932 A (paragraph number 0008, FIG. 3) Japanese Unexamined Patent Publication No. 2000-167775 (paragraph number 0020, FIG. 6) No. 2007-020881 (paragraph number 0019, FIGS. 1 and 4)

  As described above, according to the driver bit in which the ridge is formed in the valley groove of the cross shaft portion or the concave groove is formed in the conical surface of the cross shaft portion, the operation is performed by biting the cross shaft portion into the operation groove. It will be possible to prevent loosening from the groove and more reliably tighten the screw. However, in the situation where the fan-shaped wall of the operation groove was shaved with a driver bit and the operation groove was completely destroyed or deformed not only to the corner on the base end side of the fan-shaped wall, It is impossible to loosen the screw by biting the ridge or the loose edge. That is, the driver bits according to Patent Documents 1 to 3 are provided with a cross shaft at the operation groove and the corner on the base end side of the fan-shaped wall on the premise that at least the corner on the base end side of the fan-shaped wall remains. By tightening the ridges and loose edges of the part, the torque of the driver bit is transmitted to the fan-shaped wall, and the screw is tightened. For this reason, it is impossible to tighten and tighten the screw under the situation where the operation groove and the corner on the base end side of the fan-shaped wall are completely destroyed or deformed.

  The object of the present invention is to provide a screwdriver bit that can be loosened and removed without fail even when not only the operating groove but also the corner of the base end of the fan-shaped wall is completely destroyed or deformed. There is to do.

The present invention relates to a bit body of a screwdriver bit for performing a tightening operation on a screw 5 that has been crushed by a cruciform operation groove on a screw head and has resulted in the formation of a tapered tapered recess recess 6. A tightening operation portion 10 is provided at the lower end of 8 to be driven into the peripheral surface of the damaged recess 6 to establish a fixed state with the screw 5. the upon the vertical position, and five or more rib-like projections 11 formed projecting radially outward direction you orthogonal to the axis direction of the bit body 8, between the rib-like projection 11 adjacent Each rib-like protrusion 11 includes a rib peripheral surface 13 formed in a cylindrical outer surface shape having a uniform outer diameter along the axial direction of the bit body 8, and the rib peripheral surface 13. It is composed of a pair of trough grooves 14 and 14 sandwiched between the ribs. A biting portion 20 to be driven into the peripheral wall 7 of the damaged recess 6 is formed at the corner portion of the lower outer edge of each rib-like protrusion 11 defined by the lower end surface of the rib 11 and the rib peripheral surface 13. To do.

Of the two ridge lines where the rib peripheral surface 13 and the valley side peripheral surface 14 intersect, the ridge line located on the loose operation direction side is set to the loose side edge 15. Then, the valley-side peripheral surface 14 of the loose side edges 15, the elongation direction d1 of that person direction be perpendicular to the axial direction of the bit body 8, the virtual circle defined by the rotation locus of the loose side edges 15 An angle α formed by the tangent line d2 passing through the edge 15 can be set to 60 degrees or more and 120 degrees or less.

The lower end surface of the rib-like projection 11, toward the outer direction you perpendicular to the axial direction of the bit body 8 are inclined surfaces 16 inclined downward is formed, the elongation of the elongation direction and the rib peripheral surface 13 of the inclined surface 16 It is possible to adopt a form in which the angle β of the biting portion defined by the direction is set to an acute angle. The extending direction of the inclined surface 16 here refers to the direction connecting the rotation center (center portion O) of the lower end surface of the tightening operation portion 10 and the center point of the rib circumferential surface 13, or the center portion O and the rib circumference. It means the direction connecting the vertex 18 of the surface 13.

  The lower end surface of the rib-shaped protrusion 11 is an inclined surface 35 that is inclined downward toward the valley-side peripheral surface 14 that forms the loose side edge 15, and the extending direction of the inclined surface 35 and the extending direction of the loose side edge 15. The angle γ defined by the above can be set to an acute angle. The extending direction of the inclined surface here means the direction connecting the vertices 17 and 18 of the rib peripheral surface 13.

  In the driver bit 3 according to the present invention, the biting portion 20 to be driven into the peripheral wall 7 of the damaged recess 6 is formed at the corner portion of the lower outer edge of the five or more rib-like protrusions 11. For example, as shown in FIG. 1, the driver bit 3 is attached to the grip 2 of the driver 1 for use, and the tightening operation portion 10 is inserted into the damaged recess 6 of the head of the screw 5. Then, the upper end of the grip 2 is hit with a hammer or the like, and the biting portion 20 is driven into the peripheral wall 7 of the damaged recess 6. As shown in FIG. 4, each biting portion 20 can be firmly fixed to the screw 5, so that the screw 5 is loosened by rotating the driver bit 3 in the loosening direction from this fixed state. Can be removed from the fastened state. However, in some cases, the driver bit 3 can be rotated in the tightening direction.

  As described above, the driver bit 3 according to the present invention obtains a strong fixing state by driving the biting portion 20 into the peripheral wall 7 of the damaged recess 6, and tightens the screw 5 by rotating from the fixing state. Since the screw 5 can be loosely operated and the screw 5 can be tightened or loosened regardless of the presence of the operation groove or the fan-shaped wall, even the corner of the base end of the fan-shaped wall is not completely destroyed. Even the deformed screw 5 can be removed without any problem. That is, even if it is screw 5 which was not able to be tightened and loosened in the form which makes a fan-shaped wall the object of engagement like the driver bit concerning patent documents 1-3, it becomes possible to remove without a problem.

  More specifically, the conventional driver bits described in Patent Documents 1 to 3 are stuck in the slightly remaining operation grooves and the corners of the fan-shaped wall, so that they match the operation grooves. A cross shaft having a cross-shaped cross section provided with a plurality of rib-shaped protrusions is provided. On the other hand, the driver bit according to the present invention is provided with five or more rib-like projections 11 and performs a tightening operation by obtaining a fixed state in driving regardless of the operation groove. Therefore, even the screw 5 completely broken or deformed up to the corner of the base end portion of the fan-shaped wall can be removed without any problem. When the number of rib-like projections 11 is less than 5, the rotational torque applied to the fixing portion of the peripheral wall 7 of each biting portion 20 increases, so the peripheral wall 7 of the damaged recess 6 is not prepared during the rotation operation. There is a risk of scraping.

In addition, by driving a screwdriver bit having a cross-shaped cross section defined in Patent Documents 1 to 3 or specified in JIS standard toward the screw, the screw and the rib-like protrusion are between It is conceivable to remove the screws after obtaining a fixed state. However, in the case of the driver bit according to Patent Document 3, as shown in FIG. 21, before the corner portion 115 of the lower outer edge of each rib-like protrusion 111 of the driver bit 103 abuts, It becomes difficult for the surface 113 to hit the peripheral wall 7 of the damaged recess 6 and to drive the corner portion 115 into the peripheral wall 7. That is, even if the upper end of the grip is struck with a hammer or the like, the rib peripheral surface 113 slides up on the peripheral wall 7, making it difficult to accurately drive the corner portion 115 into the peripheral wall 7, and establishing a firm fixing state with the screw 5. Can not do it. In the case of a JIS standard driver bit, as shown in FIG. 22, the corner portion 115 on the lower outer edge of each rib-like protrusion 111 of the driver bit 103 hits the bottom surface 116 of the damaged recess 6, and the corner portion 115 is surrounded by the peripheral wall. I ca n’t type in 7. As described above, it is difficult to drive the corner portion 115 into the peripheral wall 7 with a driver bit having a cross-shaped cross section with a narrowed shape, and it is impossible to establish a strong fixing state with the screw 5. I must say.
On the other hand, if the rib peripheral surface 13 of each rib-like protrusion 11 is formed in the shape of a vertical cylindrical outer surface as in the present invention, the rib peripheral surface 13 may contact the peripheral wall 7 of the damaged recess 6. However, the biting portion 20 formed at the corner portion of the lower outer edge of the rib-like protrusion 11 can be reliably driven into the peripheral wall 7. As a result, a firm fixing state can be established between the biting portion 20 and the peripheral wall 7, so that the rotational torque of the driver bit 3 is accurately transmitted to the screw 5 and the screw 5 is securely tightened. can do.

  The angle α formed by the horizontal extension direction d1 of the valley side peripheral surface 14 constituting the loose side edge 15 and the tangent line d2 passing through the edge 15 of the virtual circle defined by the rotation locus of the loose side edge 15 is 60 degrees or more and 120 degrees or less is preferable. According to the knowledge of the present inventors, when the angle α is less than 60 degrees, the loose side edge 15 easily slides on the peripheral wall 7 of the damaged recess 6 and accurately transmits the rotational torque of the driver bit 3 to the screw 5. It becomes difficult. If the angle α exceeds 120 degrees, the peripheral wall 7 of the damaged recess 6 may be scraped off during the rotation operation. If the angle α exceeds 120 degrees, it is difficult to process, and it is difficult to make the number of rib-shaped protrusions 11 5 or more. In view of the above-mentioned problem of the upslip on the peripheral wall 7 of the damaged recess 6 of the loose side edge 15 and the problem of scraping the peripheral wall 7, the angle α is preferably about 90 degrees (80 degrees or more and 100 degrees or less). In particular, 90 degrees is optimal.

  As shown in FIG. 1 and FIG. 4, an inclined surface 16 is formed on the lower end surface of the rib-like protrusion 11 so as to incline downward in the horizontal outward direction. The extending direction of the inclined surface 16 and the extension of the rib peripheral surface 13 are formed. The angle β of the biting portion defined by the direction is preferably set to an acute angle. In this way, when the angle β is set to an acute angle, the force is smaller than that in the form in which the lower end surface of the rib-like protrusion 11 is formed as a flat surface (form in which the angle β is set to 90 degrees). Therefore, the biting portion 20 can be driven into the peripheral wall 7, so that the tightening operation using the driver bit 3 can be advanced more quickly. Further, the biting portion 20 is driven deeper into the peripheral wall 7 so that a more secure fixing state can be established between the biting portion 20 and the peripheral wall 7. Therefore, it is possible to obtain the driver bit 3 that can be transmitted reliably and is therefore highly reliable. Even when a foreign object enters the bottom of the damaged recess 6, the foreign object hits the lower end surface of the tightening operation part 10, and the biting part 20 does not float away from the peripheral wall 7 during the driving operation. Including the tightening operation can be performed reliably.

  As shown in FIGS. 18 and 19, the lower end surface of the rib-shaped protrusion 11 is an inclined surface 35 that is inclined downward toward the valley-side peripheral surface that forms the loose side edge 15, and the extending direction of the inclined surface 35 is The angle γ defined by the extension direction of the loose side edge 15 can be set to an acute angle. According to this, it becomes possible to drive the biting portion 20 into the peripheral wall 7 of the damaged concave portion 6 with a smaller force than in the form in which the lower end surface of the rib-like protrusion 11 is formed as a flat surface, and therefore, the driver The tightening work using the bit 3 can be advanced more quickly. Further, the biting portion 20 is driven deeper into the peripheral wall 7 so that a more secure fixing state can be established between the biting portion 20 and the peripheral wall 7. I can tell you with certainty. Accordingly, it is possible to obtain the driver bit 3 with higher reliability.

It is a whole front view showing a driver bit concerning a 1st embodiment of the present invention. It is a top view which shows the driver bit which concerns on 1st Embodiment of this invention. It is a perspective view of the principal part for demonstrating the driving | running state to the screw of the driver bit which concerns on 1st Embodiment. It is a top view for demonstrating the driving | running state to the screw of the driver bit which concerns on 1st Embodiment. FIG. 5 is a cross-sectional view taken along line AA of FIG. 4 and is a longitudinal front view of a main part for explaining a driving state of the driver bit according to the first embodiment into a screw. It is a perspective view of the principal part which shows the driver bit which concerns on 2nd Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 2nd Embodiment of this invention. It is a perspective view of the principal part which shows the driver bit which concerns on 3rd Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 3rd Embodiment of this invention. It is a perspective view of the principal part which shows the driver bit which concerns on 4th Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 4th Embodiment of this invention. It is a perspective view of the principal part which shows the driver bit which concerns on 5th Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 5th Embodiment of this invention. It is a perspective view of the principal part which shows the driver bit which concerns on 6th Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 6th Embodiment of this invention. It is a perspective view of the principal part which shows the driver bit which concerns on 7th Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 7th Embodiment of this invention. It is a perspective view of the principal part which shows the driver bit which concerns on 8th Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 8th Embodiment of this invention. It is a vertical front view of the principal part which shows the driver bit which concerns on 9th Embodiment of this invention. It is a figure for demonstrating the problem of the conventional driver bit. It is a figure for demonstrating the problem of the conventional driver bit.

(Embodiment 1) FIGS. 1 to 5 show an embodiment in which a driver bit according to the present invention is applied to a manual driver. As shown in FIG. 1, the driver 1 includes a grip 2 and a replaceable driver bit 3. The driver bit 3 can be extracted from the grip 2 by pushing the chuck 4 provided at the mounting base end of the grip 2 against a spring (not shown).

  The driver bit 3 includes a bit body 8 formed of a hexagonal shaft, a main shaft 9 extending from the lower end of the bit body 8, and a tightening operation unit 10 formed at the lower end of the main shaft 9. As shown in FIGS. 3 and 4, the tightening operation unit 10 is used for the purpose of loosening a screw 5 such that most or all of the sector wall is scraped to form a broken recess 6.

  That is, as shown in FIG. 3, when the fan-shaped wall that defines the operation groove of the screw 5 is scraped off to the extent that the original shape is not stopped and a broken recess 6 is formed, a cross-axis shaped driver bit of JIS standard is formed. Then, it becomes difficult to engage this with the operation groove. Further, even when the base end of the fan-shaped wall is scraped off and the operation groove is completely lost, it is difficult to rotate the screw 5 with the driver bit described in Patent Documents 1 to 3. Even in such a case, in the driver bit 3 according to the present embodiment, as shown in FIG. 1, the lower end of the main shaft 9 is arranged so that the rotational torque can be reliably transmitted to the screw 5 and the screw 5 can be loosened. A simple tightening / operation part 10 was formed.

  The tightening operation part 10 is composed of five rib-like protrusions 11 that are radially projected outward in the horizontal direction and five trough grooves 12 that are formed between adjacent rib-like protrusions 11. ing. That is, the tightening operation portion 10 is formed by alternately forming five rib-like protrusions 11 and five valley grooves 12.

  Each rib-like protrusion 11 is composed of a rib peripheral surface 13 formed in the shape of a vertical cylindrical outer surface, and valley-side peripheral surfaces 14 and 14 of a pair of valley grooves 12 sandwiching the rib peripheral surface 13 therebetween. That is, the rib peripheral surface 13 of each rib-like protrusion 11 is formed in a vertical cylindrical outer surface shape having a uniform outer diameter dimension in the vertical direction. As shown in FIG. 2, adjacent rib-shaped protrusions 11 are formed at equiangular intervals in the circumferential direction.

Two ridge lines are formed at both ends in the circumferential direction of the rib peripheral surface 13 of each rib-shaped protrusion 11 by the rib peripheral surface 13 and the pair of valley side peripheral surfaces 14 and 14, and one of these ridge lines is on the loose side. The edge 15 is set. Specifically, as shown in FIGS. 1 and 2, when the screw is loosened in the direction of arrow D (see FIG. 2), the ridge line on the side where the rotational torque is transmitted to the screw 5 is located on the loosening direction side. The loose edge 15 is set.
As shown in FIG. 2, it is defined by the horizontal extension direction d1 of the valley side peripheral surface constituting the slack side edge 15 and a tangent line passing through the edge of the virtual line defined by the rotation locus of the slack side edge. The angle α is set to 65 degrees.

  An inclined surface 16 is formed on the lower end surface of the rib-like protrusion 11 so as to incline downward in the horizontal outward direction. Specifically, as shown in FIGS. 1, 2, and 4, the shaft center portion (the portion indicated by the center point O) at the lower end of the tightening operation portion 10 is depressed, and each rib-like protrusion 11 has a recess. At the lower end, there is formed a substantially triangular inclined surface 16 which is defined by two vertices 17 and 18 of each rib peripheral surface 13 and three points of the center point O and which is inclined downward toward the horizontal outer direction. . As a result, as shown in FIG. 4, the angle β defined by the extending direction d3 of the inclined surface 16 and the extending direction d4 (vertical direction) of the slack side edge 15 can be set to an acute angle. In the present embodiment, the extending direction d3 of the inclined surface 16 is a direction connecting the central portion (position where the distances from the two vertices 17 and 18 are equal) and the center point O of the lower end edge of the rib peripheral surface. means. In the present embodiment, the angle β is set to 70 degrees.

In the driver bit 3 having the above-described configuration, the corner portion of the lower outer edge of each rib-like projection 11 defined by the inclined surface 16 of the rib-like projection 11 and the rib peripheral surface 13 is driven into the peripheral wall of the damaged recess. It becomes the biting part 20.
Specifically, in order to tighten and tighten the screw 5 using the screwdriver bit 3, first, after the positioning of the tightening operation portion 10 to the damaged recess 6 of the screw 5, the upper end of the grip 2 is struck with a hammer or the like. 4 and FIG. 5, the biting portion 20 is driven into the peripheral wall of the damaged recess. Thus, the biting portion 20 can be caused to enter the peripheral wall 7 of the damaged recess 6 of the screw 5 and the fastening operation portion 10 can be firmly fixed to the screw 5. Next, the driver bit 3 is rotated to the loosening operation side (counterclockwise), and the rotational torque of the driver bit 3 is transmitted to the screw 5 via the biting portion 20, whereby the screw 5 is loosened and tightened. Can be removed from the state. As described above, according to the driver bit 3 according to the present embodiment, the screw 5 can be tightened and loosened regardless of the presence of the operation groove and the fan-shaped wall, so that the corner of the base end portion of the fan-shaped wall is reached. Even if the screw 5 is completely broken or deformed as shown in FIG. 3, it can be removed without any problem.

  In such a driving operation, the rib peripheral surface 13 of each rib-shaped protrusion 11 is formed in a vertical cylindrical outer surface having a uniform outer diameter in the vertical direction, and the lower end surface of the rib-shaped protrusion 11 is horizontally It is formed in the inclined surface 16 inclined downward toward the direction, and it is advantageous that the angle β of the biting portion 20 is formed at an acute angle. That is, when the rib peripheral surface 13 of each rib-shaped protrusion 11 is formed in the shape of a vertical cylindrical outer surface, as shown in FIG. 21, the rib peripheral surface 113 is unavoidable in a driver bit having a cross-shaped cross section. There is room for the problem that the first contact with the peripheral wall 7 of the damaged recess 6 or the problem that the corner portion 115 of the lower outer edge of each rib-like protrusion 111 of the driver bit 103 hits the bottom surface 116 of the damaged recess 6 as shown in FIG. Therefore, the biting portion 20 formed at the corner portion of the lower outer edge of the rib-like protrusion 11 can be reliably driven into the peripheral wall 7. Thereby, a firm fixed state can be reliably obtained between the biting portion 20 and the peripheral wall 7.

In addition, when the angle β of the biting portion 20 is set to an acute angle, the lower end surface of the rib-like protrusion 11 is formed as a flat surface, and the angle β of the biting portion is formed at a right angle. Thus, the biting portion 20 can be driven into the peripheral wall 7 with a smaller force, and therefore the tightening work using the driver bit 3 can be advanced more quickly. Further, since the biting portion 20 can be driven deeper into the peripheral wall 7 with a smaller force, it is also excellent in that a strong fixing state can be easily and reliably obtained between the biting portion 20 and the peripheral wall 7. ing.
In addition, even when a foreign object enters the bottom of the damaged recess 6, the foreign object hits the lower end surface of the tightening operation portion 10, and the biting portion 20 does not float away from the peripheral wall 7 during the driving operation. The fastening operation including the driving operation can be reliably performed.

  In addition, since the number of rib-shaped protrusions 11 is five or more (in this embodiment, five), the rotational torque applied to each driving portion of the peripheral wall 7 can be reduced, so that the peripheral wall of the damaged recess 6 during the rotation operation. It is possible to avoid the occurrence of inconvenience that the inner peripheral surface of the damaged recess 6 is widened by inadvertently scraping 7.

  According to the knowledge of the present inventors, when the angle α is less than 60 degrees, the loose side edge 15 easily slides on the peripheral wall 7 of the damaged recess 6 and accurately transmits the rotational torque of the driver bit 3 to the screw 5. It becomes difficult. If the angle α exceeds 120 degrees, the peripheral wall 7 of the damaged recess 6 may be scraped off during the rotation operation. If the angle α exceeds 120 degrees, it is difficult to process, and it is difficult to make the number of rib-shaped protrusions 11 5 or more. In the present embodiment, since the angle α is set to 65 degrees, problems such as an upslip on the peripheral wall 7 of the damaged recess 6 of the loose side edge 15 and an inadvertent scraping of the peripheral wall 7 do not occur, and the driver bit is accurately set. 3 can be transmitted to the screw 5 to remove the screw 5 from the tightened state.

Embodiment 2 FIGS. 6 and 7 show a driver bit according to a second embodiment of the present invention. There, only the shape of the inclined surface 16 is different from the first embodiment. That is, in the driver bit 3 according to the second embodiment, a regular pentagonal flat surface 25 is formed at the center of the lower end of the tightening operation portion 10, and in addition, the rib-shaped protrusion 11 is formed from each side of the pentagon. An inclined surface 16 that is inclined downward toward the lower end edge of the rib peripheral surface 13 is formed. Since the other points are the same as those of the first embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted.

Third Embodiment FIGS. 8 and 9 show a driver bit according to a third embodiment of the present invention. There, it differs from the previous first embodiment in that the lower end surface of the tightening operation portion is a flat surface. In other words, the first embodiment is different from the first embodiment in that the inclined surface 16 is eliminated to form a flat surface. Further, an angle formed by the horizontal extension direction d1 of the valley side peripheral surface 14 constituting the loose side edge 15 and the tangent line d2 passing through the edge 15 of the virtual circle defined by the rotation locus of the loose side edge 15 The difference from the first embodiment is that α is 90 degrees. Since the other points are the same as those of the first embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted.

(Fourth Embodiment) FIGS. 10 and 11 show a driver bit according to a fourth embodiment of the present invention. In this case, the number of rib-like projections 11 is six, which is different from the first embodiment. That is, the tightening / loosening operation portion 10 of the driver bit 3 according to the present embodiment is formed between the six rib-shaped protrusions 11 that are formed to project radially outward and the adjacent rib-shaped protrusions 11. And six valley grooves 12. Further, the tightening operation portion 10 of the driver bit 3 according to the present embodiment is different from the first embodiment in that the inclined surface 16 is eliminated and the lower end surface of the tightening operation portion 10 is a flat surface. . Further, in the present embodiment, the tangent line d2 passing through the edge 15 of the virtual circle defined by the horizontal extension direction d1 of the valley side peripheral surface 14 constituting the loose side edge 15 and the rotation locus of the loose side edge 15 is provided. The angle α formed by and is set to 65 degrees. Since the other points are the same as those in the first embodiment, the same members are denoted by the same reference numerals and description thereof is omitted.

Fifth Embodiment FIGS. 12 and 13 show a driver bit according to a fifth embodiment of the present invention. There, the edge 30 located on the opposite side of the loose side edge 15 across the rib peripheral surface 13, that is, the edge 30 located on the tightening side is inclined upward toward the tightening direction. This is different from the fourth embodiment. Since the other points are the same as those in the fourth embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted. According to this, since the circumferential width dimension of the rib-shaped protrusion 11 can be increased as going upward, the rigidity of the rib-shaped protrusion 11 can be improved.

Sixth Embodiment FIGS. 14 and 15 show a driver bit according to a sixth embodiment of the present invention. There, it is formed by a horizontal extension direction d1 of the valley side peripheral surface 14 constituting the loose side edge 15 and a tangent line d2 passing through the edge 15 of the virtual circle defined by the rotation locus of the loose side edge 15. The difference between the fourth embodiment and the previous embodiment is that the angle α is 90 degrees. Since the other points are the same as those in the fourth embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted.

(Seventh Embodiment) FIGS. 16 and 17 show a driver bit according to a seventh embodiment of the present invention. There, it differs from the previous sixth embodiment in that the circumferential width of the rib peripheral surface 13 is reduced. Since the other points are the same as those in the sixth embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted. Thus, if the circumferential width dimension of the rib peripheral surface 13 is reduced, the biting portion 20 can be driven into the peripheral wall 7 of the damaged recess 6 with a smaller force, thereby facilitating the driving operation. be able to.

Eighth Embodiment FIGS. 18 and 19 show a driver bit according to an eighth embodiment of the present invention. In this case, the lower end surface of the rib-shaped protrusion 11 is an inclined surface 35 inclined downward toward the valley-side peripheral surface 14 forming the loose side edge 15, and the extending direction of the inclined surface 35 and the loose side edge The point that the angle γ defined by the extension direction is set to an acute angle is different from the previous second embodiment. The extending direction of the inclined surface referred to here indicates a direction in which the two vertices 17 and 18 of the rib peripheral surface 13 are connected as shown in FIG. Since the other points are the same as those of the second embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted. Thus, by providing the inclined surface 35, the driving operation can be facilitated as in the case of the first embodiment.

Ninth Embodiment FIG. 20 shows a driver bit according to a ninth embodiment of the present invention. Here, the entire lower end surface of the tightening / loosening operation portion 10 is a concave curved surface, and an inclined surface 16 is formed on the lower end surface of the rib-like protrusion so as to incline downward in the horizontal direction. Is different from the first embodiment. Since the other points are the same as those of the first embodiment, the same members are denoted by the same reference numerals and the description thereof is omitted.

  The configuration of the driver bit 3 in the present invention is not limited to the first to ninth embodiments, and in particular, the number of the rib-like protrusions 11 may be six or more. Also in the driver bit 3 described in the third to seventh embodiments, the inclined surface 16 can be formed on the lower end surface of the tightening operation portion 10.

3 Driver Bit 5 Screw 6 Damaged Recess 7 Peripheral Wall 8 Bit Body 10 Fastening Operation Part 11 Rib-shaped Projection 12 Valley Groove 13 Rib Circumferential Surface 14 Valley Side Peripheral Surface 15 Loose Side Edge 16 Inclined Surface

Claims (4)

A screwdriver bit for performing a tightening operation on the screw (5) that has been crushed by the cross-shaped operation groove on the screw head and has led to the formation of a tapered tapered recess (6),
At the lower end of the bit body (8), a tightening operation part (10) for driving into the peripheral surface of the damaged recess (6) and establishing a fixed state with the screw (5) is provided,
Tightening slow operation unit (10), when the bit body (8) has a vertical orientation, the bit body (8) 5 or more, which is formed projecting radially outward direction you perpendicular to the axial direction of the Rib-shaped projections (11) and a trough (12) formed between adjacent rib-shaped projections (11),
Each rib-like protrusion (11) sandwiches the rib peripheral surface (13) between the rib peripheral surface (13) formed in a cylindrical outer surface shape having a uniform outer diameter along the axial direction of the bit body (8). It is composed of a pair of trough grooves (14, 14),
The bite that is driven into the peripheral wall (7) of the damaged recess (6) in the corner portion of the lower outer edge of each rib-like projection (11) defined by the lower end surface of the rib-like projection (11) and the rib peripheral surface (13) A driver bit, characterized in that an attaching portion (20) is formed. Of the two ridge lines where the rib peripheral surface (13) and the valley side peripheral surface (14) intersect, the ridge line located on the loose operation direction side is set to the loose side edge (15),
Valley peripheral surfaces constituting the slack side edge (15) of (14), and the bit body axis direction perpendicular to that the direction of elongation direction (8) (d1), the rotation locus of the loose side edges (15) The driver bit according to claim 1, wherein an angle (α) formed by a tangent (d2) passing through the edge (15) of the virtual circle defined by (1) is set to 60 degrees or more and 120 degrees or less. The lower end surface of the rib-like projections (11), the inclined surface toward the outer direction to downward inclined you orthogonal to the axial direction of the bit body (8) (16) is formed,
The driver bit according to claim 1 or 2, wherein an angle (β) of the biting portion defined by the extending direction of the inclined surface (16) and the extending direction of the rib peripheral surface (13) is set to an acute angle. The lower end surface of the rib-like protrusion (11) is an inclined surface (35) that is inclined downward toward the valley side peripheral surface (14) forming the loose side edge (15),
The driver bit according to claim 2, wherein an angle (γ) defined by the extending direction of the inclined surface (35) and the extending direction of the loose side edge (15) is set to an acute angle.

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