Low-resistance anti-cracking screw structure

Abstract

A low-resistance anti-cracking screw structure comprises a low-resistance screw, the low-resistance screw is divided into a screw body upper section, a screw body middle section, a screw body lower section and a conical screw tail from top to bottom, at least one chip removal groove is formed in the screw body lower section in a concave mode, and the chip removal groove is gradually deepened from top to bottom. The chip removal groove inclines relative to the center axis of the low-resistance screw to form a chip removal rotation angle ranging from 10 degrees to 20 degrees, the chip removal groove inclines relative to the radial direction to form an inclined slope angle ranging from 79 degrees to 89 degrees, the maximum depth of the second groove section is smaller than 55% of the radius of the lower section of the screw body, the lower side of the chip removal groove is gradually shrunk to form a resistance reduction included angle ranging from 15 degrees to 20 degrees, and the resistance reduction included angle ranges from 15 degrees to 20 degrees. A spiral lower thread is arranged on the surface of the lower section of the screw body and the surface of the screw tail, the lower thread and the chip removal groove are the same in inclination direction relative to the center shaft of the low-resistance screw, and the lower thread is continuous and separates the chip removal groove.

Description

Technical Field

[0001] The invention relates to a low-resistance anti-cracking screw structure, and in particular to a low-resistance anti-cracking screw structure with high structural strength and good chip removal efficiency. Background Art

[0002] According to the invention, a cut-end screw is a self-tapping screw, in which a groove is cut at the tail end of the screw for chip removal during self-tapping. The screw is widely used in objects that have been drilled in advance. However, cutting the groove actually damages the screw itself, which reduces the strength of the screw and causes a poor yield of the screw. The existing cut-end screw often causes the cone-shaped screw tail to be damaged due to the groove cut at the tail end, or the cone-shaped screw tail is not used directly, which also reduces the self-tapping ability of the screw.

[0003] In the prior art, the grooves at the tail end of the screws are usually cut directly by planing, which is equivalent to directly destroying the spiral structure, greatly reducing the structural strength, which is not conducive to manufacturing and use, and may also cause the screws to break. When the debris enters the groove, there may be problems with the chip removal speed and uneven force, and the resistance also has concerns about affecting the quality of the screw lock.

[0004] Therefore, it is necessary to improve the chip removal efficiency and reduce the influence of resistance while maintaining the structural strength of the screw for manufacturing and use.

[0005] Therefore, the inventor has considered this and thought of the idea of invention, and then designed it based on many years of experience, and after much discussion and trial sample testing, and many revisions and improvements, he launched the present invention. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a low-resistance anti-cracking screw structure in view of the above-mentioned deficiencies in the prior art.

[0007] Technical features for solving the problem:

[0008] The present invention provides a low-resistance anti-cracking screw structure, which includes a low-resistance screw. The low-resistance screw is divided into an upper screw body section, a middle screw body section, a lower screw body section and a conical screw tail from top to bottom. Among them, at least one chip evacuation groove is recessed in the lower screw body section. The chip evacuation groove gradually becomes deeper from top to bottom, and the chip evacuation groove is inclined with a chip evacuation spiral angle relative to the central axis of the low-resistance screw. The chip evacuation spiral angle is between 10 degrees and 20 degrees. The chip evacuation groove is divided into a flat first groove section and an inclined second groove section. The second groove section is inclined with an inclined slope angle relative to the radial direction. The inclined slope angle is between 79 degrees and 89 degrees. The maximum depth of the second groove section is less than 55% of the radius of the lower screw body section. The two side surfaces of the chip evacuation groove gradually narrow near the screw tail at the lower side and have a resistance reduction included angle. The resistance reduction included angle is between 15 degrees and 20 degrees, which can prevent excessive extrusion and increase in resistance when debris starts to enter and leave the chip evacuation groove, thereby increasing the full penetration ability during screwing. A spiral lower thread is provided on the surface of the lower screw body section and the screw tail. The lower thread has the same inclination direction as the chip evacuation groove relative to the central axis of the low-resistance screw, and the lower thread is continuous so that the chip evacuation groove is separated by the lower thread.

[0009] Further, the thread angle of the lower thread is between 37 degrees and 43 degrees.

[0010] Further, the depth of the first groove section is between 15% and 20% of the radius of the lower screw body section.

[0011] Further, a spiral upper thread is provided on the surface of the upper screw body section. The spiral direction of the upper thread is opposite to that of the lower thread.

[0012] Preferably, the chip evacuation spiral angle is 15 degrees.

[0013] Preferably, the inclined slope angle is 84 degrees.

[0014] Preferably, the resistance reduction included angle is 18 degrees.

[0015] Further, both side surfaces of the chip evacuation groove are inclined, and the included angle between the two side surfaces of the chip evacuation groove is 65 degrees.

[0016] Further, the inclination angle of one side surface of the chip evacuation groove is 45 degrees and the inclination angle of the other side surface is 20 degrees.

[0017] Further, the maximum depth of the groove section is between 40% and 55% of the radius of the lower screw body section.

[0018] The first main object of the present invention is that the screw tail of the low-resistance screw can abut against an object to be screwed, and the low-resistance screw is rotated to be screwed in and a hole is scraped and expanded by the lower thread to achieve the self-tapping effect, so that the low-resistance screw can be screwed to the object. Since at least one chip evacuation groove is recessed in the lower section of the screw body to reserve extra space, the chips generated after the lower thread is scraped can enter and exit the chip evacuation groove, which can accelerate the speed and efficiency of discharging the chips out of the hole, and can avoid the accumulation of chips from affecting the self-tapping efficiency, and can also avoid the accumulated chips from colliding with the low-resistance screw and causing it to skew and affect the screwing quality. Moreover, the lower thread is continuous, so that the chip evacuation groove is separated by the lower thread, thus avoiding the chips from being discharged not in the spiral direction and blocking.

[0019] The second main object of the present invention is that since the chip evacuation groove is only recessed in the lower section of the screw body and not on the screw tail, the structure of the screw tail is not damaged, so the structural strength is relatively strong, avoiding the situation that the screw tail breaks during processing and the screw tail breaks in the hole when the low-resistance screw is screwed out of the hole in the future. Because the chip evacuation groove gradually becomes deeper from top to bottom, the chip evacuation groove is deeper closer to the bottom of the low-resistance screw. Thus, it can cope with the greater resistance encountered at the front end when the low-resistance screw is self-tapping and accommodate more chips, thereby enhancing the chip evacuation efficiency. And since the maximum depth of the second groove section is less than 55% of the radius of the lower section of the screw body, while ensuring the chip evacuation efficiency, the structural strength of the lower section of the screw body is ensured to avoid breakage and damage during processing, manufacturing or use. Also, since the chip evacuation groove is inclined with a chip evacuation spiral angle relative to the central axis of the low-resistance screw and the lower thread and the chip evacuation groove are inclined in the same direction relative to the central axis of the low-resistance screw, the chips can smoothly enter the chip evacuation groove, further enhancing the chip evacuation efficiency.

[0020] The third main object of the present invention is that since the two side surfaces of the lower side of the chip evacuation groove gradually converge near the screw tail to form a resistance reduction angle, when the low-resistance screw starts to penetrate the target object, the bottom of the chip evacuation groove is relatively narrow, avoiding the resistance of the low-resistance screw from rising due to the extrusion of chips in the chip evacuation groove at the initial stage, and at the same time preventing the low-resistance screw from shaking due to excessive resistance at the initial stage of screwing, thereby being able to reduce the resistance and improve the full penetration ability of the low-resistance screw.

[0021] Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description and related drawings. Description of the Drawings

[0022] Figure 1 It is a three-dimensional view of the present invention.

[0023] Figure 2 It is a front view of the present invention, and the screw tail part is sectioned for easy viewing.

[0024] Figure 3 For the present invention Figure 2 is the sectional view taken along line A-A.

[0025] Figure 4 For the present invention Figure 2 is the sectional view taken along line B-B.

[0026] Figure 5 For the present invention Figure 2 is the sectional view taken along line C-C.

[0027] Figure 6 is the front view of the lower part of the screw body and the screw tail of the present invention.

[0028] Figure 7 For the present invention Figure 6 is the sectional view taken along line D-D.

[0029] Figure 8 is the partial enlarged view of the lower part of the screw body and the screw tail of the present invention.

[0030] Figure 9 is the schematic diagram of the depth of the chip discharge groove of the present invention, with the thread part removed for easy viewing.

[0031] Figure 10 is the schematic diagram of the screw advancement of the present invention.

[0032] Figure 11 is the schematic diagram of the included angle part of the present invention.

[0033] Figure 12 is the schematic diagram of the usage state of the present invention.

[0034] Figure 13 is the schematic diagram of chip discharge at the lower part of the screw body during the actual use of the present invention.

[0035] Figure 14 is the schematic diagram of the first state of the middle part of the screw body of the present invention.

[0036] Figure 15 is the schematic diagram of the second state of the middle part of the screw body of the present invention.

[0037] Figure 16 is the schematic diagram of the third state of the middle part of the screw body of the present invention.

[0038] Figure 17 is the schematic diagram of the fourth state of the middle part of the screw body of the present invention.

[0039] Figure 18 is the schematic diagram of the fifth state of the middle part of the screw body of the present invention.

[0040] Figure 19 is the schematic diagram of the sixth state of the middle part of the screw body of the present invention.

[0041] Figure 20 Schematic diagram of the first aspect of the upper section of the screw body of the present invention.

[0042] Figure 21 Schematic diagram of the second aspect of the upper section of the screw body of the present invention.

[0043] Figure 22 Schematic diagram of the third aspect of the upper section of the screw body of the present invention.

[0044] Figure 23 Schematic diagram of the fourth aspect of the upper section of the screw body of the present invention.

[0045] Figure 24 Schematic diagram of the fifth aspect of the upper section of the screw body of the present invention.

[0046] Figure 25 Schematic diagram of the sixth aspect of the upper section of the screw body of the present invention.

[0047] Figure 26 Schematic diagram of the first aspect of the screw head of the present invention.

[0048] Figure 27 Schematic diagram of the second aspect of the screw head of the present invention.

[0049] Figure 28 Schematic diagram of the third aspect of the screw head of the present invention.

[0050] Figure 29 Schematic diagram of the fourth aspect of the screw head of the present invention.

[0051] Figure 30 Schematic diagram of the fifth aspect of the screw head of the present invention.

[0052] Symbol description:

[0053] Part of the present invention:

[0054] Low-resistance screw - (10) Lower thread - (101) Upper thread - (102) Upper section of the screw body - (11) Middle section of the screw body - (12) Lower section of the screw body - (13) Chip evacuation groove - (131) First groove section - (1311) Second groove section - (1312) Screw tail - (14) Screw head - (15)

[0055] Hole - (20)

[0056] Chip evacuation spiral angle - (X)

[0057] Inclined slope angle - (Y)

[0058] Drag reduction included angle - (Z) DETAILED DESCRIPTION

[0059] In order to further understand and appreciate the purpose, features and effects of the present invention, please refer to the following [Brief Description of the Drawings] for details:

[0060] Please first Figure 1 and Figure 2 As shown, the present invention provides a low resistance anti-crack screw structure, which includes a low resistance screw (10), the low resistance screw (10) is divided from top to bottom into an upper screw body section (11), a middle screw body section (12), a lower screw body section (13) and a conical screw tail (14), wherein the lower screw body section (13) is concavely provided with at least one chip removal groove (131), and cooperates with Figures 3 to 7 As shown, the chip removal groove (131) gradually becomes deeper from top to bottom. Figure 8 As shown, the chip removal groove (131) is inclined with respect to the central axis of the low resistance screw (10) to have a chip removal angle (X), and the chip removal angle (X) is between 10 degrees and 20 degrees. Figure 9 As shown, the chip removal groove (131) is divided into a flat first groove section (1311) and an inclined second groove section (1312), the second groove section (1312) is inclined relative to the radial direction and has an inclined slope angle (Y), the inclined slope angle (Y) is between 79 degrees and 89 degrees, the maximum depth of the second groove section (1312) is less than 55% of the radius of the lower section (13) of the screw body, Figure 10 and Figure 11 As shown, the lower side of the chip groove (131) close to the screw tail (14) is gradually reduced between the two side surfaces to have a drag reduction angle (Z), and the drag reduction angle (Z) is between 15 degrees and 20 degrees to prevent excessive extrusion and increase resistance when debris begins to enter and leave the chip groove (131), thereby increasing the complete penetration ability during screw rotation. A spiral lower thread (101) is provided on the surface of the lower section (13) of the screw body and the screw tail (14), and the lower thread (101) and the chip groove (131) are inclined in the same direction relative to the central axis of the low resistance screw (10), and the lower thread (101) is continuous so that the chip groove (131) is separated by the lower thread (101).

[0061] Depend on Figure 12 and Figure 13As shown, when in actual use, the screw tail (14) of the low-resistance screw (10) can be abutted against an object to be screwed, and the low-resistance screw (10) is rotated to be screwed in and a hole (20) is scraped and expanded by the lower thread (101) to achieve the self-tapping effect, so that the low-resistance screw (10) can be screwed to the object. Since at least one chip discharge groove (131) is recessed in the lower section (13) of the screw body to reserve extra space, the chips generated after the lower thread (101) is scraped can enter and exit the chip discharge groove (131), which can accelerate the speed and efficiency of discharging the chips out of the hole (20), and can avoid the accumulation of chips from affecting the self-tapping efficiency, and can avoid the accumulated chips from colliding with the low-resistance screw (10) and causing it to skew and affect the screwing quality. Moreover, the lower thread (101) is continuous, so that the chip discharge groove (131) is separated by the lower thread (101), thereby preventing the chips from being discharged not in the spiral direction and being blocked.

[0062] With the above structure, since the chip discharge groove (131) is only recessed in the lower section (13) of the screw body and not on the screw tail (14), the structure of the screw tail (14) is not damaged, so the structural strength is relatively high, avoiding the situation that the screw tail (14) breaks during processing and the screw tail (14) breaks in the hole (20) when the low-resistance screw (10) is unscrewed and removed from the hole (20) in the future. Because the chip discharge groove (131) gradually becomes deeper from top to bottom, the chip discharge groove (131) is deeper closer to the bottom of the low-resistance screw (10). Thus, it can respond to the greater resistance encountered at the front end when the low-resistance screw (10) is self-tapping and accommodate more chips, thereby enhancing the chip discharge efficiency. And since the maximum depth of the second groove section (1312) is less than 55% of the radius of the lower section (13) of the screw body, while ensuring the chip discharge efficiency, the structural strength of the lower section (13) of the screw body is ensured to avoid breakage and damage during processing and use. Also, since the chip discharge groove (131) is inclined with a chip discharge spiral angle (X) relative to the central axis of the low-resistance screw (10) and the lower thread (101) and the chip discharge groove (131) are inclined in the same direction relative to the central axis of the low-resistance screw (10), the chips can smoothly enter the chip discharge groove (131), further enhancing the chip discharge efficiency.

[0063] Moreover, since the two side surfaces of the chip discharge groove (131) gradually converge near the screw tail (14) at the lower side and have a resistance reduction angle (Z), when the low-resistance screw (10) starts to penetrate the target object, the bottom of the chip discharge groove (131) is relatively narrow, avoiding the increase in resistance caused by the extrusion of chips in the chip discharge groove (131) at the initial stage of the low-resistance screw (10), and at the same time preventing the low-resistance screw (10) from shaking due to excessive resistance at the initial stage of screw rotation, thereby being able to reduce the resistance and improve the full penetration ability of the low-resistance screw (10).

[0064] Thus, the low-resistance screw (10) of the present invention improves the chip evacuation efficiency while ensuring the structural strength, which is greatly beneficial for use.

[0065] As Figure 8 shown, the present invention provides a low-resistance and anti-cracking screw structure, wherein the tooth angle of the lower thread (101) is between 37 degrees and 43 degrees.

[0066] As Figure 9 shown, the present invention provides a low-resistance and anti-cracking screw structure, wherein the depth of the first groove section (1311) is between 15% and 20% of the radius of the lower section (13) of the screw body.

[0067] As Figure 2 shown, the present invention provides a low-resistance and anti-cracking screw structure, wherein a spiral upper thread (102) is provided on the surface of the upper section (11) of the screw body, and the spiral direction of the upper thread (102) is opposite to that of the lower thread (101), so that the low-resistance screw (10) presents a structure with positive and negative threads.

[0068] As Figure 8 shown, the present invention provides a low-resistance and anti-cracking screw structure, wherein the chip evacuation spiral angle (X) is 15 degrees.

[0069] As Figure 9 shown, the present invention provides a low-resistance and anti-cracking screw structure, wherein the inclined slope angle (Y) is 84 degrees.

[0070] As Figure 10 and Figure 11 shown, the present invention provides a low-resistance and anti-cracking screw structure, wherein the drag reduction included angle (Z) is 18 degrees.

[0071] The present invention provides a low-resistance and anti-cracking screw structure, wherein both sides of the chip evacuation groove (131) are inclined, the included angle between both sides of the chip evacuation groove (131) is 65 degrees, the inclination angle of one side of the chip evacuation groove (131) is 45 degrees and the inclination angle of the other side is 20 degrees, and debris can slide into the chip evacuation groove (131) from the place with a larger inclination angle and accumulate debris at the place with a smaller inclination angle.

[0072] The present invention provides a low-resistance and anti-cracking screw structure, wherein the maximum depth of the second groove section (1312) is between 40% and 55% of the radius of the lower section (13) of the screw body.

[0073] As Figures 14 to 19 shown, it is a schematic diagram of different states of the middle section (12) of the screw body, and there are different functions and appearances according to the state of the surface of the middle section (12) of the screw body.

[0074] AsFigures 20 to 25 As shown, it is a schematic diagram of different states of the upper section (11) of the screw body, which has different functions or rotation directions according to the state of the upper thread (102).

[0075] The top of the low-resistance screw (10) has a screw head (15) for convenient screwing. Figures 26 to 30 As shown, it is a schematic diagram of different states of the screw head (15), which has different functions according to the state of the screw head (15).

[0076] The above is only a preferred embodiment of the present invention, and it cannot be used to limit the scope of implementation of the present invention; that is, all equal changes and modifications made according to the scope of the patent application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A low-resistance anti-cracking screw structure, characterized in that, It includes a low-resistance screw, which is divided into an upper screw body section, a middle screw body section, a lower screw body section and a conical screw tail from top to bottom. Among them: At least one chip removal groove is recessed in the lower screw body section. The chip removal groove gradually becomes deeper from top to bottom, and the chip removal groove is inclined with a chip removal spiral angle relative to the central axis of the low-resistance screw. The chip removal spiral angle is between 10 degrees and 20 degrees. The chip removal groove is divided into a flat first groove section and an inclined second groove section. The second groove section is inclined with an inclined slope angle relative to the radial direction. The inclined slope angle is between 79 degrees and 89 degrees. The maximum depth of the second groove section is less than 55% of the radius of the lower screw body section. The two side surfaces of the chip removal groove gradually narrow near the screw tail at the lower side and have a resistance reduction included angle. The resistance reduction included angle is between 15 degrees and 20 degrees, which can prevent excessive extrusion when debris starts to enter and leave the chip removal groove, thereby increasing the resistance, and thus increasing the complete penetration ability during screw rotation. A spiral lower thread is provided on the surface of the lower screw body section and the screw tail. The lower thread has the same inclination direction as the chip removal groove relative to the central axis of the low-resistance screw, and the lower thread is continuous, so that the chip removal groove is separated by the lower thread.

2. The low-resistance anti-cracking screw structure according to claim 1, characterized in that, The thread angle of the lower thread is between 37 degrees and 43 degrees.

3. The low-resistance anti-cracking screw structure according to claim 1, characterized in that, The depth of the first groove section is between 15% and 20% of the radius of the lower screw body section.

4. The low-resistance anti-cracking screw structure according to claim 1, characterized in that, A spiral upper thread is provided on the surface of the upper screw body section. The spiral direction of the upper thread is opposite to that of the lower thread.

5. The low-resistance crack-proof screw structure according to claim 1, wherein The chip removal spiral angle is 15 degrees.

6. The low-resistance anti-cracking screw structure according to claim 1, wherein The inclined slope angle is 84 degrees.

7. The low-resistance crack-proof screw structure according to claim 1, characterized in that, The resistance reduction included angle is 18 degrees.

8. The low-resistance crack-proof screw structure according to claim 1, characterized in that, Both side surfaces of the chip removal groove are inclined, and the included angle between the two side surfaces of the chip removal groove is 65 degrees.

9. The low-resistance crack-proof screw structure according to claim 8, characterized in that, The inclination angle of one side surface of the chip removal groove is 45 degrees and the inclination angle of the other side surface is 20 degrees.

10. The low-resistance crack-proof screw structure according to claim 1, wherein, The maximum depth of the groove section is between 40% and 55% of the radius of the lower screw body section.

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