Fasteners, screwdriver bits and forming punches

Abstract

The present invention provides a fastener, a screwdriver head and a forming punch. The fastener includes a screw head and a screw rod. The screw head includes an inner annular surface surrounding an insertion hole. The inner annular surface has six arc curved portions and six arc driving portions arranged alternately with the arc curved portions. The arc driving portion has an arc surface segment, a straight surface segment extending from the arc surface segment along a tangential direction, and an extension segment connecting the straight surface segment. The design of the insertion hole can increase the contact area with the screwdriver head to increase the degree of engagement and reduce the torque loss of the fastener during the driving process. The screwdriver head has an external feature corresponding to the insertion hole, so that it can be inserted into the insertion hole and drive the fastener by rotation. The forming punch can form the insertion hole on the screw head of the fastener by forging.

Description

Technical Field

[0001] The present invention relates to a fastener, a screwdriver bit, and a forming punch, and in particular to a fastener capable of improving meshing degree and not easily slipping during the tightening process, a screwdriver bit suitable for driving the fastener, and a forming punch for forging the fastener. Background Art

[0002] See Figure 1 Currently, a typical fastener 1 often has a groove 11 that is concave downward from the top surface and is roughly in the shape of six petals. This groove 11 is commonly known as a plum blossom hole. Due to tolerances generated during manufacturing, this groove 11 is prone to not effectively engage with the driving tool. This will result in the user being unable to fully convert the applied force into torque to drive the fastener to rotate when driving the fastener with a screwdriver, resulting in a loss of driving torque. The screwdriver may even slip out of the groove 11, causing damage to the inner wall of the groove 11 and the screwdriver head. This will make the fastener 1 difficult to remove or continue to lock. Therefore, the user needs to use additional tools to remove and replace the fastener 1, resulting in increased construction costs and delayed construction time. On the other hand, to cope with harsh operating environments, the fastener 1 is often coated on its outer surface to prevent rust. However, this coating often accumulates in the groove 11, causing clogging of the groove 11. This makes it difficult to insert a screwdriver bit into the groove 11, further reducing the degree of engagement. When the degree of engagement is low, it is easy for the fastener 1 to wobble or swing during locking. When the groove 11 is severely clogged, the screwdriver bit may even be unable to be inserted into the groove 11, rendering the fastener 1 unusable. Therefore, although this plum blossom-shaped groove 11 has been widely used in the industry, there is still significant room for improvement. Summary of the Invention

[0003] The object of the present invention is to provide a fastener which can improve the degree of engagement and is not easy to slip during the tightening process.

[0004] The fastener of the present invention is characterized in that: the fastener includes a screw head and a screw rod extending downward from the screw head, the screw head includes an inner annular surface surrounding and defining a top surface and connecting the top surface, the inner annular surface surrounding and defining an insertion hole recessed downward from the top surface, and having six circular arc portions arranged annularly spaced apart from each other, and six circular arc driving portions staggered with and connected to the circular arc portions, each circular arc driving portion having two adjacent circular arc portions connected on opposite sides, the circular arc driving portion having an arc surface section connecting a corresponding circular arc portion and being inversely curved with the circular arc portion, a straight surface section extending from the arc surface section along a tangential direction, and an extension section connecting the straight surface section and another corresponding circular arc portion, and the screw rod forms at least one thread extending axially helically on its outer circumference.

[0005] In the fastener of the present invention, the straight surface section and the extended section of each arc driving portion of the screw head form an angle that is acute, right, obtuse or rounded.

[0006] In the fastener of the present invention, the curvature radius of each circular arc portion of the screw head is greater than the curvature radius of each arc surface segment.

[0007] The fastener of the present invention, wherein the curvature radius of each arc portion of the screw head is greater than the curvature radius of each arc surface segment, and the curvature radius of the arc surface segment is greater than the curvature radius of the fillet between the straight surface segment and the extended segment of the screw head.

[0008] In the fastener of the present invention, the extended section of each arc driving portion of the screw head is a straight surface or a curved surface.

[0009] Another object of the present invention is to provide a driver bit suitable for driving the fastener.

[0010] The screwdriver head of the present invention is suitable for driving the fastener, and is characterized in that: the screwdriver head includes a connecting portion and a driving head extending downward from the connecting portion, the driving head includes six circular arc portions arranged in an annular manner and spaced apart from each other, and six arc driving portions arranged alternately with and connected to the circular arc portions, the opposite sides of each arc driving portion are respectively connected to two adjacent circular arc portions, the arc driving portion has an arc surface section connected to a corresponding circular arc portion and in an inverse curve to the circular arc portion, a straight surface section extending from the arc surface section along a tangent direction, and an extension section connecting the straight surface section and another corresponding circular arc portion.

[0011] In the screwdriver head of the present invention, the straight section and the extended section of each arc driving portion of the driving head form an angle that is acute, right, obtuse or rounded.

[0012] In the screwdriver head of the present invention, the curvature radius of each circular arc portion of the driving head is greater than the curvature radius of each arc surface segment.

[0013] The screwdriver head of the present invention has a curvature radius of each arc portion of the driving head that is greater than the curvature radius of each arc surface segment, and the curvature radius of the arc surface segment is greater than the curvature radius of the fillet between the straight surface segment and the extended segment of the driving head.

[0014] In the screwdriver head of the present invention, the extended section of each arc driving portion of the driving head is a straight surface or a curved surface.

[0015] Another object of the present invention is to provide a forming punch for forging the fastener.

[0016] The forming punch of the present invention is suitable for forging the insertion hole of the fastener, and is characterized in that: the forming punch includes a main body and a punch extending downward from the main body, the punch includes six circular arc portions arranged in a ring shape and spaced apart from each other, and six arc driving portions arranged alternately with the circular arc portions and connected to the circular arc portions, the opposite sides of each arc driving portion are respectively connected to two adjacent circular arc portions, the arc driving portion has an arc surface section connected to a corresponding circular arc portion and in an inverse curve to the circular arc portion, a straight surface section extending from the arc surface section along the tangent direction, and an extension section connecting the straight surface section and another corresponding circular arc portion.

[0017] In the forming punch of the present invention, the straight surface section and the extended section of each arc driving portion of the punch form an angle that is an acute angle, a right angle, an obtuse angle or a rounded angle.

[0018] In the forming punch of the present invention, the curvature radius of each circular arc portion of the punch is greater than the curvature radius of each arc surface segment.

[0019] The forming punch of the present invention, wherein the curvature radius of each circular arc portion of the punch is greater than the curvature radius of each arc surface segment, and the curvature radius of the arc surface segment is greater than the curvature radius of the fillet between the straight surface segment and the extended segment of the punch.

[0020] In the forming punch of the present invention, the extended section of each arc driving portion of the punch is a straight surface or a curved surface.

[0021] The beneficial effect of the present invention is that the extended section in the insertion hole can allow the corresponding part of the screwdriver head to lean against it, and the angle formed by each extended section and the corresponding straight section can also increase the contact area with the screwdriver head, thereby improving the degree of engagement. Therefore, even if the insertion hole and the screwdriver head have manufacturing tolerances, they can be eliminated by the aforementioned method of improving the degree of engagement. In this way, in addition to reducing the loss of torque during the driving process, it can also prevent the screwdriver head from slipping off the insertion hole during the screwing process, avoiding wear and damage to the screwdriver head or the insertion hole, thereby avoiding the loss of construction time and the cost of replacing the fastener due to damage to the insertion hole, improving overall construction efficiency and reducing construction costs. In addition, the angle formed by the extended section and the straight section can also be used to accommodate excess paint, so that when the fastener surface is coated, it will not be blocked in the insertion hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a top view illustrating the groove of a general fastener;

[0023] Figure 2 is a top view illustrating an embodiment of the fastener of the present invention;

[0024] Figure 3 is a perspective view illustrating the three-dimensional appearance of the embodiment;

[0025] Figure 4 is a schematic diagram illustrating the structure of the insertion hole of the embodiment;

[0026] Figure 5 is a partial side sectional view illustrating an embodiment of a screwdriver bit of the present invention;

[0027] Figure 6 is a three-dimensional diagram illustrating the matching state of the fastener and the screwdriver head. Figure 6 Only a portion of the driving head of the screwdriver bit is shown;

[0028] Figure 7 is a schematic diagram illustrating the structure of the drive head of the embodiment;

[0029] Figure 8 is a schematic diagram illustrating a state in which the driving head is inserted into the insertion hole;

[0030] Figure 9 A partial side sectional view illustrating an embodiment of a forming punch of the present invention;

[0031] Figure 10 is a three-dimensional diagram illustrating the state of the fastener and the forming punch. Figure 10 Only a portion of the punch of the forming punch is shown; and

[0032] Figure 11 It is a schematic diagram illustrating the structure of the punch of the embodiment. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0034] See Figure 2 、 Figure 3 ,and Figure 4The embodiment of the fastener 2 of the present invention comprises a screw head 21 and a screw rod 22 integrally extending downward from the bottom end of the screw head 21. The screw head 21 includes a top surface 211 and an inner annular surface 212 connected to the top surface 211. The inner annular surface 212 defines a downwardly recessed insertion hole 214 and has six circular curved portions 215 arranged annularly and spaced apart from each other, and six circular driving portions 216 interlaced with and connected to the circular curved portions 215. Each arc driving portion 216 has two adjacent arc curved portions 215 connected on opposite sides. The arc driving portion 216 includes an arc segment 217 that connects to the corresponding arc curved portion 215 and is inversely curved to the arc curved portion 215, a straight segment 218 that extends tangentially from the arc segment 217, and an extension segment 219 that connects the straight segment 218 and the corresponding other arc curved portion 215. The extension segment 219 can be a straight surface or a curved surface, thereby forming an angle A with the straight segment 218 that can be acute, right, obtuse, or rounded. The rounded corner design can disperse stress and prevent damage during driving. The screw 22 has at least one thread 221 formed on its outer circumference, extending helically in the axial direction. In this embodiment, the curvature radius of the arc portion 215 is greater than the curvature radius of the arc surface segment 217 , and when the angle A is a rounded angle, the curvature radius of the arc surface segment 217 is greater than the curvature radius of the angle A.

[0035] See Figure 5 、 Figure 6 ,and Figure 7, is an embodiment of a screwdriver bit 3 of the present invention. The fastener 2 is adapted to be driven by a screwdriver bit 3. The screwdriver bit 3 comprises a connecting portion 31 for mounting on a driving tool, and a driving head 32 extending downward from the connecting portion 31. The driving head 32 includes six circularly spaced portions 321 arranged in an annular pattern, and six arcuate driving portions 322 interlaced with and connected to the circularly curved portions 321. Opposite sides of each arcuate driving portion 322 connect two adjacent circularly curved portions 321. Each arcuate driving portion 322 comprises an arcuate surface section 323 connecting a corresponding arcuate portion 321 and forming an inverse curve relative to the arcuate portion 321; a straight surface section 324 extending tangentially from the arcuate surface section 323; and an extended section 325 connecting the straight surface section 324 and the corresponding arcuate portion 321. The extended section 325 can be a straight surface or a curved surface, thereby forming an angle B with the straight surface section 324, which can be acute, right, obtuse, or rounded. In this embodiment, the radius of curvature of the arcuate portion 321 is greater than the radius of curvature of the arcuate section 323. When the angle B is rounded, the radius of curvature of the arcuate section 323 is greater than the radius of curvature of the angle B. For ease of explanation, the detailed structure of the drive head 32 and the detailed structure of the insertion hole 214 of the fastener 2 are named the same. These two components with the same name are similar in shape and can engage or abut each other. However, they are ultimately part of the fastener 2 and the screwdriver bit 3, rather than the same component, and are therefore distinguished by different numbers.

[0036] See Figure 5 、 Figure 6 ,and Figure 8When the screwdriver bit 3 is inserted into the insertion hole 214, the extended section 219 in the insertion hole 214 allows the corresponding part of the screwdriver bit 3 to abut against it. The angle A formed by each extended section 219 and the corresponding straight section 218 also increases the contact area with the screwdriver bit 3, thereby improving the degree of meshing. Therefore, even if there are manufacturing tolerances between the insertion hole 214 and the screwdriver bit 3, these can be eliminated by the aforementioned method of improving the degree of meshing. In addition to reducing the loss of torque during the driving process, this also prevents the screwdriver bit 3 from slipping out of the insertion hole 214 during the screwing process, avoiding wear and damage to the screwdriver bit 3 or the insertion hole 214, and thus preventing the damaged parts from rusting in the atmospheric environment. Due to the significant improvement in torque transmission force, when the screwdriver head 3 is driven by the electric tool to drive the fastener 2 to rotate, the power loss of the electric tool can be reduced. In addition, since the engagement between the screwdriver head 3 and the insertion hole 214 is improved, when the screwdriver head 3 is inserted into the insertion hole 214, the fastener 2 can be firmly positioned on the screwdriver head 3 and is not easy to fall off. This allows the user to operate the screwdriver head 3 with one hand without having to fix the fastener 2 with the other hand. This not only provides the convenience of one-handed operation, but also prevents the fastener 2 from shaking or swinging during the driving process, thereby improving the stability of the operation. The space formed by the angle A between the extended section 219 and the straight section 218 makes it easier to insert and position the screwdriver bit 3, and can avoid stress concentration and reduce wear. In addition, when the fastener 2 is attached with a coating for rust prevention or other purposes, the angle A can also be used to accommodate excess paint to prevent the paint from clogging the entire insertion hole 214 and causing the screwdriver bit 3 to be poorly inserted, thereby overcoming the problem that the general plum blossom hole is easily clogged by paint and reduces the degree of engagement.

[0037] See Figure 9 、 Figure 10 ,and Figure 11, is an embodiment of a forming punch 4 of the present invention. The fastener 2 is forged using a forming punch 4. The forming punch 4 comprises a body 41 and a punch 42 extending downward from the body 41 and used to form the insertion hole 214. The punch 42 includes six circular arc sections 421 arranged annularly and spaced apart from each other, and six arc driving sections 422 interlaced with and connected to the circular arc sections 421. Each arc driving section 422 has two adjacent arc sections 421 connected on opposite sides. The arc driving section 422 includes an arc segment 423 that connects to a corresponding arc section 421 and is inversely curved to the arc section 421; a straight section 424 that extends tangentially from the arc segment 423; and an extended section 425 that connects the straight section 424 to the corresponding arc section 421. The extension section 425 can be a straight surface or a curved surface, thereby forming an angle C with the straight surface section 424 that is an acute angle, a right angle, an obtuse angle or a rounded angle. In this embodiment, the radius of curvature of the arc portion 421 is greater than the radius of curvature of the arc surface section 423, and when the angle C is a rounded angle, the radius of curvature of the arc surface section 423 is greater than the radius of curvature of the angle C. For the sake of convenience, the detailed structure of the punch 42 and the detailed structure of the insertion hole 214 of the fastener 2 are named the same. The two components with the same name are similar in shape and can engage or abut each other, but they are ultimately part of the fastener 2 and the forming punch 4 rather than the same component, so they are distinguished by different numbers in the label. The insertion hole 214 of the fastener 2 can be forged by the punch 42 of the forming punch 4. At this time, the screw 22 has not yet been processed with the thread 221, so it is not shown. Figure 10 middle.

[0038] In summary, the insertion hole 214 of the present invention can increase the contact area with the screwdriver head 3, thereby improving the degree of engagement and reducing the torque loss during the driving process, and can prevent the screwdriver head 3 from slipping out of the insertion hole 214 during the driving process, reducing the difficulty of operation and extending the service life of the screwdriver head 3 and the fastener 2, so that the purpose of the present invention can indeed be achieved.

[0039] The above description is only a preferred embodiment of the present invention, but it is not intended to limit the scope of the present invention. Anyone familiar with this technology can make further improvements and changes on this basis without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of this application.

Claims

1. A fastener, characterized in that: The fastener includes a screw head and a screw rod extending downward from the screw head, the screw head includes an inner annular surface defining a top surface and connected to the top surface, the inner annular surface defines an insertion hole recessed downward from the top surface, and has six circular arc portions arranged in an annular manner and spaced apart from each other, and six arc driving portions staggered with and connected to the circular arc portions, each arc driving portion has two adjacent circular arc portions connected on opposite sides, the arc driving portion has an arc surface section connecting a corresponding circular arc portion and inversely curved with the circular arc portion, a straight surface section extending from the arc surface section along the tangential direction, and an extension section connecting the straight surface section and another corresponding circular arc portion, the curvature radius of each circular arc portion is greater than the curvature radius of each arc surface section, and the screw rod forms at least one thread extending axially helically on the outer circumference.

2. The fastener according to claim 1, wherein: The straight surface section and the extended section of each circular arc driving portion of the screw head form an angle that is an acute angle, a right angle, an obtuse angle or a rounded angle.

3. The fastener according to claim 2, wherein: The curvature radius of the arc surface section of the screw head is greater than the curvature radius of the fillet between the straight surface section and the extended section.

4. The fastener according to claim 1, wherein: The extended section of each circular arc driving portion of the screw head is a straight surface or a curved surface.

5. A screwdriver bit suitable for driving the fastener according to claim 1, characterized in that: The screwdriver head includes a connecting portion and a driving head extending downward from the connecting portion, the driving head includes six circular arc portions arranged in a ring shape and spaced apart from each other, and six circular arc driving portions arranged alternately with and connected to the circular arc portions, the opposite sides of each circular arc driving portion are respectively connected to two adjacent circular arc portions, the circular arc driving portion has an arc surface section connected to a corresponding circular arc portion and inversely curved with the circular arc portion, a straight surface section extending from the arc surface section along the tangent direction, and an extension section connecting the straight surface section and another corresponding circular arc portion, the curvature radius of each circular arc portion is greater than the curvature radius of each arc surface section.

6. The screwdriver bit according to claim 5, characterized in that: The straight section and the extended section of each arc driving portion of the driving head form an angle that is an acute angle, a right angle, an obtuse angle or a rounded angle.

7. The screwdriver bit according to claim 6, characterized in that: The curvature radius of the arc surface section of the driving head is greater than the curvature radius of the fillet between the straight surface section and the extended section.

8. The screwdriver bit according to claim 5, characterized in that: The extended section of each arc driving portion of the driving head is a straight surface or a curved surface.

9. A forming punch suitable for forging the insertion hole of the fastener according to claim 1, characterized in that: The forming punch includes a main body and a punch extending downward from the main body, the punch includes six circular arc portions arranged in a ring shape and spaced apart from each other, and six arc driving portions arranged alternately with and connected to the circular arc portions, the opposite sides of each arc driving portion are respectively connected to two adjacent circular arc portions, the arc driving portion has an arc surface section connected to a corresponding circular arc portion and in the reverse direction of the circular arc portion, a straight surface section extending from the arc surface section along the tangent direction, and an extension section connecting the straight surface section and another corresponding circular arc portion, the curvature radius of each circular arc portion is greater than the curvature radius of each arc surface section.

10. The forming punch according to claim 9, characterized in that: The straight surface section and the extended section of each arc driving portion of the punch form an angle that is an acute angle, a right angle, an obtuse angle or a rounded angle.

11. The forming punch according to claim 10, characterized in that: The curvature radius of the arc surface section of the punch is greater than the curvature radius of the fillet between the straight surface section and the extended section.

12. The forming punch according to claim 9, characterized in that: The extended section of each arc driving portion of the punch is a straight surface or a curved surface.

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