JP2006057662A - Cross slot screw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cross slot screw capable of being rotated and driven by fitting a cross blade of a driver bit into a cross slot and preventing the slot groove from being deformed or broken securely when the screw is rotated and driven by the driver bit and excessive force acts on the groove of the cross slot. <P>SOLUTION: A rotary receiving part 23 with a cylindrical inner face is formed by cylindrical acting inner faces 18, 18 on both side walls 17 of each groove 15 and a substantially horizontal step part 16 formed in a lower end part of both cylindrical acting inner faces in a substantially intermediate part of the groove 15 in which the blade 24 of the driver bit 1 in the cross slot 4 of the cross slot screw 3 is fitted. This cross slot screw 3 is rotated and driven by the driver bit 1 having the blade 25 provided with a rotary acting part with a cylindrical outer face fitted into the rotary receiving part 23 with the cylindrical inner face. The rotary receiving part 23 with the cylindrical inner face may be formed by the cylindrical acting inner faces formed on both side walls in outer side end parts of each groove and the substantially horizontal step part formed in the lower end part of both cylindrical acting inner faces. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cross-recessed screw and a cross-recessed screw that allows the driver bit to be securely tightened without sliding up from the screw drive hole when screwed by a driver bit. The present invention relates to a driver bit for rotationally driving.

  Conventionally, in order to tighten or loosen the screw, an engagement hole is formed in the screw head to engage the driver bit, and a cross-recessed screw with a cross-shaped groove formed in the engagement hole is widely used. It has been. The basic shape of this cross-recessed screw is determined by JIS standards, etc., but the original shape has been applied to the parts other than the basic shape as necessary, and special shapes have been added as necessary. A cross hole may be formed. In that case, special driver bits adapted to these shapes may be used.

  Such a cross-recessed screw and a driver bit for driving the cross-shaped screw have a shape as shown in FIG. 5, for example. That is, FIG. 5 is a cross-sectional view of the main part of FIG. 5B and a cross-sectional view of FIG. 5C using a driver bit 51 having a cruciform blade 52 at the tip as shown in the side view of FIG. The conventional example which rotationally drives the screw 53 with a cross hole provided with the cross hole 54 as shown in the head top view of this is shown. The shape of the cross hole 54 in the cross hole screw 53 is gradually narrowed at an angle α from the surface 56 of the head 55 toward the neck portion 57 side of the screw, and below the cross hole lower end 58 is below. A bottom 60 is formed where the bit ends do not contact.

  When such a cross-recessed screw 53 is rotationally driven by the driver bit 51, for example, as shown in FIG. 6, with respect to the cross-recessed hole 54 of the cross-recessed screw 53, the shape and size corresponding to the screw. When the driver bit 51 is selected and the cruciform blade 52 is inserted, the tip inclination angle α of the cruciform blade 52 of the driver bit 51 coincides with the internal inclination angle α of the cruciform hole 54, and the most distal portion 59 of the driver bit 51 is obtained. And the cross hole lower end portion 58 substantially coincide with each other. Therefore, at the time of final insertion, the outer peripheral portion of the most distal end portion 59 and the inner peripheral portion of the cross hole lower end portion 58 are substantially as shown in FIGS. The wings of the cruciform wing 52 are fitted with the slight gaps L in the bit fitting grooves of the cruciform holes 54.

  When tightening the cross-recessed screw 53 from this state, the driver bit 51 is rotationally driven as shown in FIG. As a result, the wings of the cruciform blade 52 and the grooves of the cruciform hole 54 where the slight gaps L existed as described above rotate so as to contact each other in the driving direction. During this rotation, the portion where the ridge line portion 61 in the rotational direction of each wing portion of the driver bit 51 comes into contact with the side wall 62 of the groove of the cross hole becomes a tapered contact with the inclination angle α. The rotating force generates a force that causes the driver bit 51 to escape from the cross hole in the direction of the angle α.

  Further, in order to prevent the driver bit 51 from slipping out, when the driver bit 51 is rotationally driven while being pressed into the cross hole 54 with a large force, particularly the most distal end portion 59 and the cross hole lower end portion 58 of the driver bit 51 are formed. The rotational driving force is concentrated while a large thrust acts on the biting portion 63 that comes into contact. Therefore, the screw material near the biting portion 63 is deformed and the screw near the biting portion 63 to which an excessive force acts is deformed because it is rotationally driven with a large force in a state where a large frictional force is applied at this portion. The material will be damaged.

  Due to the deformation and breakage of the screw material particularly in the biting portion 63 in such a cross hole, the driver bit 51 is more easily pulled out, and when the thrust is further applied to the driver bit 51 to suppress it, the groove of the cross hole 54 rotates. It will be damaged until it becomes impossible. This phenomenon also occurs when the screw is loosened in addition to the above-described screw tightening, and it is difficult to give a rotational driving force that causes the screw to pull out against the thrust while giving a particularly large thrust. It is.

  In addition, even if the change in thrust is such that the deformation or breakage of the screw material does not occur, the force in the rotational direction changes due to the change. On the other hand, if it is set to transmit a predetermined rotational torque and perform tightening, it becomes impossible to give the set desired rotational torque.

As a countermeasure, for example, in Japanese Patent Application Laid-Open No. 8-145024, a horizontal step portion is provided at each end edge of each bit fitting groove of the screw head, and the horizontal step portion is directed to the center portion of the screw neck portion. Each of the inclined groove portions is formed to extend, and at the bottom thereof, a substantially conical bottom surface is formed. The driver bit is provided so as to be fitted in the vicinity of the horizontal step portion. There has been proposed a screw in which a vertical end wall portion having a predetermined depth is formed on each end edge portion.
JP-A-8-145042

  In the screw disclosed in the above-mentioned patent document, by receiving thrust in the screw direction of the driver bit at the horizontal step portion, change in rotational torque of the screw due to change in thrust is prevented, and formation of the vertical end wall portion and this vertical By using a driver bit equipped with a cruciform blade that fits the end wall, the contact between the two is eliminated from the taper contact at the groove side wall portion of the cruciform blade and the cross hole, and parallel to the axis of the screw. By making line contact, it is possible to prevent the screw from coming out when the screw is driven to rotate.

  However, in the screw as described above, line contact parallel to the axis of the screw is performed at the groove side wall portion of the cruciform blade and the cross hole. Therefore, when a rotational driving force is applied to the screw by the driver bit, Since the rotational driving force concentrates on this contact portion, the groove side wall portion of the cross hole is often deformed. If the groove side wall portion of the cross hole is deformed in this way, eventually, the inclined groove portion directed toward the center portion receives a rotational driving force, and thus the same problem as the conventional one shown in FIG. 6 occurs. However, it is not an appropriate solution.

  Therefore, according to the present invention, an excessive force is applied to the groove of the cross hole when the screw is driven to rotate by the driver bit in the cross hole screw in which the cross bit of the driver bit is fitted into the cross hole and driven to rotate. The main object of the present invention is to provide a cross-recessed screw that can reliably prevent the groove from being deformed or broken, and to provide a driver bit that rotationally drives the cross-recessed screw.

  In order to solve the above-mentioned problem, the cross-recessed screw according to the present invention is a cross-recessed screw in which a screw hole is formed with a groove in which a blade of a driver bit is fitted. A rotation receiving portion with a cylindrical inner surface is formed by a cylindrical working inner surface formed on a wall and a substantially horizontal stepped portion formed at the lower ends of both cylindrical working inner surfaces.

  Another cross-recessed screw according to the present invention is a cross-recessed screw in which a screw bit is formed with a groove that fits a blade of a driver bit, and is formed on both side walls of the outer end of each groove. The rotation receiving portion with the cylindrical inner surface is formed by the cylindrical inner working surface and the substantially horizontal step portion formed at the lower ends of both cylindrical working inner surfaces.

  Furthermore, as a driver bit having a cruciform blade for rotationally driving the novel cruciform screw according to the present invention, a cylindrical working outer surface formed to face part of both side surfaces of each wing, and both cylindrical shapes A rotation operation portion with a cylindrical outer surface is formed by a substantially horizontal end portion formed at the lower end portion of the operation outer surface.

  Since the present invention is configured as described above, in the cross hole screw in which the cross bit of the driver bit is fitted into the cross hole and driven to rotate, the screw in the cross hole is rotated when the screw is driven by the driver bit. It is possible to reliably prevent the groove from being deformed or broken due to an excessive force. In particular, in the portion where the rotational driving force acts on the screw by the driver bit, the cylindrical working inner surface can be brought into a surface contact state, so that even when a large rotational driving force acts, the groove may be deformed or damaged. Disappear. Further, the thrust of the driver bit can be reliably received by the substantially horizontal stepped portion, and the rotational torque can be transmitted stably. Furthermore, the driver bit according to the present invention is adapted to the cross hole having the shape as described above, and the screw with the cross hole can be appropriately driven to rotate.

  It consists of a groove that fits the blade of the screwdriver bit on the screw head for the purpose of preventing the groove from being deformed or damaged due to excessive force acting on the groove in the cross hole when the screw is driven by the driver bit. In a cross-recessed screw having a cross hole, a cylindrical inner surface is formed by a cylindrical working inner surface formed on both side walls of a substantially middle portion of each groove and a substantially horizontal step formed at the lower end of both cylindrical working inner surfaces. This is realized by forming a rotation receiving portion with a cross, and when rotating a screw with a cross hole provided with a cross hole of such a shape, it is formed to face part of both side surfaces of each blade of the cross blade. This is realized by rotationally driving with a driver bit having a cylindrical outer surface rotation operation portion formed by a cylindrical operation outer surface and a substantially horizontal end portion formed at the lower ends of both cylindrical operation outer surfaces.

  A first embodiment of the present invention will be described with reference to FIGS. FIGS. 1 and 2 show cross-sectional views and plan views corresponding to FIGS. 5 and 6 of the conventional example. In this embodiment, as shown in the side view of FIG. Basically, like the conventional example of FIG. 1, a driver bit 1 having a cruciform blade 2 at the tip is used, and this driver bit 1 shows a cross-sectional view of the main part of FIG. An example is shown in which a cross-recessed screw 3 having a cross-hole 4 is rotationally driven as shown in the head plan view of c). The basic shape of the cross hole 4 portion of the cross hole screw 3 is gradually narrowed at an angle α from the surface 6 of the head 5 toward the neck 7 of the screw, as in the conventional example. The bottom portion 10 is formed below the cross hole lower end portion 8 as in the conventional case.

  In the embodiment shown in FIGS. 1 and 2, in the driver bit 1 provided with the cross wing 2 and the cross-recessed screw 3 provided with the cross hole 4 in the head as described above, A horizontal step portion 16 is provided at a substantially middle portion of 15, and cylindrical working inner surfaces 18, 18 each having a substantially vertical cylindrical inner surface are formed oppositely on both side wall surfaces 17, 17 of each groove. Note that the side wall surface 17 of each groove 15 of the cross hole 4 is not exactly vertical but is set to a shape that is somewhat widened by a draft of, for example, about 5 degrees as it approaches the surface 6 of the head 5. FIG. 1 also shows a screw in which such a cross hole is formed. Accordingly, the cylindrical working inner surfaces 18 and 18 in the figure are also set so as to expand toward the screw head surface with the same draft angle.

  With such a horizontal step portion 16 and cylindrical working inner surfaces 18, 18 facing each other, a cylindrical working outer surface 20, 20 of the driver bit 1, which will be described later, and a rotational working portion 22 with a cylindrical outer surface comprising a horizontal end portion 21 are fitted. A rotation receiving portion 23 with a cylindrical inner surface for joining is formed. The horizontal step portion 16 and the horizontal end portion 21 corresponding to the horizontal step portion 16 are horizontal when the driver bit and the screw are vertical as shown in the figure, but this portion is not necessarily horizontal. If the thrust of the driver bit can be sufficiently received, it may be formed to have an appropriate inclination. However, here, for convenience of explanation, the stepped portion and the end portion are referred to as a horizontal stepped portion and a horizontal end portion.

  On the other hand, below the intermediate part of each blade 24 in the cross blade 2 of the driver bit 1, there are provided cylindrical operating outer surfaces 20, 20 extending in the substantially vertical direction and projecting to both side surfaces 25, 25 of each blade 24. Is formed with a horizontal end portion 21, thereby forming a rotation operation portion 22 with a cylindrical outer surface in the middle portion of each blade 24. The position and the shape of the rotation operation portion 22 with the cylindrical outer surface are set so that the rotation operation portion 22 with the cylindrical outer surface can be fitted into a rotation receiving portion 23 with a cylindrical inner surface formed in a substantially middle portion of each groove of the cross hole 4. In addition, since the size of the wings of the driver bit has been conventionally made somewhat smaller than the width of the cross hole of the screw that operates the driver bit, the rotation of the driver bit with the cylindrical back surface is usually performed. The outer shape of the operating portion 22 is set to be somewhat smaller than the rotation receiving portion 23 with the cylindrical inner surface of each groove of the cross hole.

  When the cross-recessed screw 3 is rotationally driven by the driver bit 1 as described above, for example, as shown in FIG. 2, the cross-recessed screw 3 corresponds to the screw. When the shape and size of the driver bit 1 is selected and the cruciform blade 2 is inserted, the tip inclination angle α of the cruciform blade 2 of the driver bit 1 coincides with the internal inclination angle α of the cruciform hole 4, and as described above. Since the rotation operating portion 22 with the cylindrical outer surface corresponds to the rotation receiving portion 23 with the cylindrical inner surface, the cruciform blade 2 is fitted into the cross hole 4.

  When the cruciform blade 2 of the driver bit 1 is finally inserted into the cruciform hole 4 of the cross-recessed screw 3, as shown in FIGS. The horizontal end portion 21 of the outer surface rotation operation portion 22 is in contact with the horizontal step portion 16 of each groove of the cross hole 4. Therefore, in the prior art as shown in FIGS. 5 and 6, there is no contact between the most distal end portion 59 of the driver bit 51 and the peripheral portion 58 of the bottom portion 60 of the cross hole 54, and therefore the biting portion. 63 no longer exists. In addition, it is the same as that of the conventional thing that each wing | blade part of the cross wing | blade 2 contacts with each bit fitting groove | channel of the cross hole 4 with a slight clearance L. FIG.

  However, as will be described later, before the ridge line portion of each blade 24 of the cruciform blade comes into contact with the side wall surface of the cross hole when the driver bit is driven to rotate, the cylindrical operation outer surface 20 of the rotary operation portion 22 with the cylinder outer surface is the cylinder inner surface. You may set so that the clearance gap between both surfaces may become smaller than the clearance gap between a blade side surface and a groove | channel inner wall surface so that it may contact | abut to the cylindrical operation | movement inner surface 18 of the rotation receiving part 23. However, even when all the intervals are set to be equal, when a predetermined rotational force is generated in the driver bit as described later, the ridge line portion of each wing of the cruciform blade first contacts the side wall surface of the cruciform hole. Even if they come into contact with each other, it is possible to make contact at both cylindrical surface portions by elastic deformation of the groove side walls thereafter.

  When tightening the cross-recessed screw 3 from this state, the driver bit 1 is rotationally driven as shown by the arrow in FIG. Thereby, between the side wall of each wing | blade part 24 of the cross blade 2 and the side wall of each groove | channel of the cross hole 4 which the slight gap L existed as mentioned above, both contact | abut in the part by the side of the drive direction. At the time of this rotation, the cylindrical working outer surface 20 of the rotation working portion 22 with a cylindrical outer surface abuts on the cylindrical working inner surface 18 of the rotation receiving portion 23 with a cylindrical inner surface as described above. The rotational drive force acts to drive the cross-recessed screw 3 to rotate. Although FIG. 2C shows an example in which the screw is driven in the tightening direction, the same effect is obtained when the screw is loosened by rotating the driver bit in the reverse direction.

  If a large torque may be applied during the rotational driving of the screw as described above, the conventional cross-hole screw as shown in FIGS. Although an excessive force sometimes acts on the biting part 63, in the present invention, there is no conventional biting part, and all the rotational driving force acts on the contact part 25. In particular, the force acting here becomes surface contact as a contact portion between the cylindrical surface and the cylindrical surface. In this contact portion 25, even if it is initially in a line contact state during rotational driving, when a rotational driving force is applied, the contact portion becomes surface contact due to elastic deformation, and the driving force increases. The area of the contact surface increases.

  In addition, the contact state at the contact portion 25 is not a cross-wing angle and a cross-hole inclination angle α in the conventional example, but is almost a right angle. Furthermore, even if a large thrust is applied to the cross-recessed screw 3 by the driver bit 1, the horizontal end portion 21 of each wing is received by the horizontal step portion 16 of each groove. There is no deformation or damage of the biting part, and no deformation or damage occurs in other parts.

  3 and 4 show a second embodiment of the present invention. In this embodiment, an example that can be effectively used for a screw smaller than the cross-recessed screw shown in FIGS. 1 and 2 is shown. That is, as apparent from comparing FIGS. 3B and 3C with FIGS. 1B and 1C of the above embodiment, in the embodiment shown in FIG. Whereas the cylindrical inner surface-equipped rotation receiving portion 23 formed in each groove is formed at a substantially intermediate portion of each groove, in the embodiment shown in FIG. 3, the cylindrical inner surface-equipped rotation receiving portion in the embodiment of FIG. An example is shown in which a cross groove on the outside of 23 is not formed, that is, a rotation receiving portion 23 with a cylindrical inner surface is formed at the outer end of each groove.

  Even with this configuration, the same effect as that of the embodiment shown in FIGS. 1 and 2 can be obtained and the same effect can be obtained. In particular, even when the cross-recessed screw is small and a sufficient cross-recess size cannot be ensured, by forming such a rotation receiving portion 23 with a cylindrical inner surface, the screw can be reliably driven to rotate. become. In addition, when the blades of the driver bit are fitted in the grooves of the cross hole and the screw is driven to rotate as in the above embodiment, there is no possibility that the ridge line portion of each blade is in contact with the inner wall surface of the groove, and the cylinder is reliably The cylindrical operation outer surface 20 of the rotation operation portion 22 with the outer surface can be brought into contact with the cylindrical operation inner surface 18 of the rotation reception portion 23 with the inner surface of the cylinder to perform rotation driving in a surface contact state, and the operation is stabilized. Therefore, the present invention is not limited to the small screw as shown in FIGS. 3 and 4, and may be applied to a relatively large screw as shown in FIGS.

  The cross-recessed screw according to the present invention can be used in various fields conventionally used, and in particular, can be used in a wide range of fields including tapping screws, ultra-small screws and the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Example of this invention, (a) is a side view of the driver bit which rotationally drives the screw with a cross hole by the Example, (b) is principal part sectional drawing of a screw with a cross hole, c) is a top plan view of the cross-recessed screw. It is a figure which shows the effect | action of 1st Example of this invention, (a) is a figure which shows the state which inserted the driver bit in the screw with a cross hole, (b) is a cross section of the AA part of (a). (C) is a figure which shows the state rotated from the state of (b) to the direction which tightens a screw with a cross hole with a driver bit. It is a figure which shows 2nd Example of this invention, (a) is a side view of the driver bit which rotationally drives the cross hole screw by the same Example, (b) is principal part sectional drawing of a cross hole screw, c) is a top plan view of the cross-recessed screw. It is a figure which shows the effect | action of 2nd Example of this invention, (a) is a figure which shows the state which inserted the driver bit in the screw with a cross hole, (b) is a cross section of the BB part of (a). (C) is a figure which shows the state rotated from the state of (b) to the direction which tightens a screw with a cross hole with a driver bit. It is a figure which shows a prior art example, (a) is a side view of the driver bit which rotationally drives the screw with a cross hole, (b) is principal part sectional drawing of a screw with a cross hole, (c) is a cross-sectional screw It is a head side top view. It is a figure which shows the effect | action of a prior art example, (a) is a figure which shows the state which inserted the driver bit in the screw with a cross hole, (b) is sectional drawing of CC part of (a), (c) is a figure which shows the state driven rotationally from the state of (b) in the direction which tightens a screw with a cross hole with a driver bit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Driver bit 2 Cross wing 3 Cross-recessed screw 4 Cross hole 5 Head 6 Surface 7 Neck 8 Cross hole lower end 10 Bottom 15 Groove 16 Step 17 Side wall surface 18 Cylindrical operation inner surface 20 Cylindrical operation outer surface 21 Horizontal end Part 22 Rotating operation part with cylindrical outer surface 23 Rotating receiving part with cylindrical inner surface 24 Wings 25 Sides

Claims (3)

In the screw with a cross hole that forms a cross hole consisting of a groove that fits the wing of the driver bit on the screw head,
A rotation receiving portion with a cylindrical inner surface is formed by a cylindrical working inner surface formed on both side walls of a substantially middle portion of each groove and a substantially horizontal step formed at the lower end of both cylindrical working inner surfaces. Cross-recessed screw. In the screw with a cross hole that forms a cross hole consisting of a groove that fits the wing of the driver bit on the screw head,
A rotation receiving portion with a cylindrical inner surface is formed by a cylindrical working inner surface formed on both side walls of the outer end portion of each groove and a substantially horizontal stepped portion formed at the lower ends of both cylindrical working inner surfaces. Cross-recessed screw. In the driver bit with a cross wing,
A cylindrical working outer surface formed with a cylindrical working outer surface formed facing a part of both side surfaces of each wing and a substantially horizontal end formed at the lower end of both cylindrical working outer surfaces. A featured driver bit.

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