TWI870082B - Low resistance anti-crack screw structure - Google Patents

Abstract

A low resistance anti-crack screw structure includes a low resistance screw, which is divided from top to bottom into an upper screw body, a middle screw body, a lower screw body and a conical screw tail, and the lower screw body is concavely provided with at least one chip removal groove, which gradually deepens from top to bottom, and the chip removal groove has a chip removal angle of 10 to 20 degrees relative to the central axis of the low resistance screw, and the chip removal groove is radially The inclination has a slope angle ranging from 79 to 89 degrees. The maximum depth of the second groove section is less than 55% of the radius of the lower section of the screw body. The chip groove tapers downward and has a drag reduction angle ranging from 15 to 20 degrees. A spiral lower thread is provided on the lower section of the screw body and the surface of the screw tail. The lower thread and the chip groove have the same inclination direction relative to the central axis of the low-resistance screw, and the lower thread is continuous and separates the chip groove.

Description

Low resistance anti-crack screw structure

The present invention relates to a low-resistance anti-crack screw structure, in particular to a low-resistance anti-crack screw structure with higher structural strength and better chip removal efficiency.

According to the information, a cut-end screw is a self-tapping screw. A groove is cut at the end of the screw to remove chips during self-tapping. It is widely used in objects that have been drilled in advance. However, cutting the groove actually damages the screw itself, which will reduce the strength of the screw and cause poor screw yield. The known cut-end screw often causes the tapered screw tail to be damaged due to the groove cut at the end, or the tapered screw tail is not used directly, which also reduces its self-tapping ability.

It is common to cut the groove at the tail end of the cut-end screw by directly planing it, which is equivalent to directly destroying the spiral structure, greatly reducing the structural strength, which is not conducive to manufacturing and use. It may also cause the screw to break. When the debris enters the groove, there may be problems with chip removal speed and uneven force, and there is also concern that the resistance will affect the quality of the screw.

Therefore, it is necessary to improve the chip removal efficiency and reduce the resistance effect while maintaining the structural strength of the screw to facilitate manufacturing and use.

Therefore, the inventor of this invention took this into consideration and came up with the idea of invention. He then designed it based on his years of experience, conducted many discussions and conducted sample tests, and made many revisions and improvements before launching this invention.

The technical problem that the present invention aims to solve is to provide a low-resistance anti-crack screw structure in response to the above-mentioned deficiencies of the existing technology.

Technical features for solving the problem:

The present invention provides a low-resistance anti-crack screw structure, which includes a low-resistance screw, which is divided from top to bottom into an upper screw body section, a middle screw body section, a lower screw body section and a tapered screw tail, wherein the lower screw body section is concavely provided with at least one chip removal groove, the chip removal groove gradually becomes deeper from top to bottom, and the chip removal groove is inclined relative to the central axis of the low-resistance screw at a chip removal angle, the chip removal 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 has an inclined slope angle relative to the radial inclination, the inclined slope angle is between 79 degrees and 20 degrees, and the chip removal groove is divided into a flat first groove section and an inclined second groove section, the second groove section has an inclined slope angle relative to the radial inclination, and the inclined slope angle is between 79 degrees and 20 degrees. 89 degrees, the maximum depth of the second groove section is less than 55% of the radius of the lower section of the screw body, the lower side of the chip removal groove is gradually reduced near the screw tail and has a drag reduction angle, the drag reduction angle is between 15 degrees and 20 degrees to prevent the debris from entering and leaving the chip removal groove and causing excessive extrusion and increasing resistance, thereby increasing the complete penetration ability during screw rotation, the lower section of the screw body and the screw tail surface are provided with a spiral lower thread, the lower thread and the chip removal groove are inclined in the same direction 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.

Furthermore, the tooth angle of the lower thread is between 37 degrees and 43 degrees.

Furthermore, a spiral upper thread is provided on the upper surface of the screw body, and the spiral direction of the upper thread is opposite to that of the lower thread.

Preferably, the chip removal angle is 15 degrees.

Preferably, the slope angle is 84 degrees.

Preferably, the drag reduction angle is 18 degrees.

The first main purpose of the present invention is to use the tail of the low-resistance screw to press against the object to be screwed, and rotate the low-resistance screw to screw in and expand a hole by scraping the lower thread to achieve the effect of self-tapping, so that the low-resistance screw can be screwed on the object. Since the lower section of the screw body is concavely provided with at least one chip removal groove to reserve additional space, the chips generated by the scraping of the lower thread can be removed. The chips can pass in and out of the chip removal groove, which can speed up the speed and efficiency of the chips being discharged out of the hole, and can avoid the accumulation of chips that affect the efficiency of self-tapping, and avoid the accumulation of chips that collide with the low-resistance screws and cause them to be skewed and affect the quality of screw fastening. The lower thread is continuous and the chip removal groove is separated by the lower thread, thereby avoiding the chips from being blocked by not being discharged in the spiral direction.

The second main purpose of the present invention is that, since the chip removal 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 strong, and the screw tail is prevented from breaking during processing and the screw tail is prevented from breaking in the hole when the low resistance screw is screwed out of the hole in the future. Because the chip removal groove gradually becomes deeper from top to bottom, the closer to the bottom of the low resistance screw, the deeper the chip removal groove is, thereby coping with the greater resistance encountered by the front end of the low resistance screw when self-tapping. The second groove section can increase the force and accommodate more debris, thereby improving the chip removal efficiency. Since the maximum depth of the second groove section is less than 55% of the radius of the lower section of the screw body, the chip removal efficiency is guaranteed while ensuring the structural strength of the lower section of the screw body to avoid breakage and damage during processing or use. In addition, since the chip removal groove is inclined at a chip removal angle relative to the central axis of the low-resistance screw and the lower thread and the chip removal groove are inclined in the same direction relative to the central axis of the low-resistance screw, the debris can smoothly enter the chip removal groove, further improving the chip removal efficiency.

The third main purpose of the present invention is that, since the lower side of the chip removal groove is close to the screw tail, the two side surfaces thereof gradually converge to form the resistance reduction angle. When the low resistance screw begins to penetrate the target object, the bottom of the chip removal groove is narrower to avoid the low resistance screw from initially squeezing the debris in the chip removal groove and causing the resistance to increase. At the same time, the low resistance screw can be prevented from shaking due to excessive resistance in the initial stage of screw rotation, thereby reducing the resistance and improving the full penetration ability of the low resistance screw.

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

Parts of this invention:

(10): Low resistance screws

(101): Bottom thread

(102): Upper thread

(11): Upper part of the snail body

(12): Middle section of the snail body

(13): Lower part of the snail body

(131): Chip removal groove

(1311): First groove segment

(1312):Second groove segment

(14):Snail tail

(15): Screw head

(20): Holes

(X): Chip removal angle

(Y): Slope angle

(Z): Drag angle

[Figure 1] is a three-dimensional diagram of the present invention.

[Figure 2] is a view before the invention, with the tail section of the screw cut into sections for easier viewing.

[Figure 3] is the A-A cross-sectional view of Figure 2 of the present invention.

[Figure 4] is the B-B cross-sectional view of Figure 2 of the present invention.

[Figure 5] is the C-C cross-sectional view of Figure 2 of the present invention.

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

[Figure 7] is the D-D cross-sectional view of Figure 6 of the present invention.

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

[Figure 9] is a schematic diagram of the chip removal groove depth of the present invention, with the threaded portion removed for easier viewing.

[Figure 10] is a schematic diagram of the screwing process of the present invention.

[Figure 11] is a schematic diagram of the corner portion of the present invention.

[Figure 12] is a schematic diagram of the present invention in use.

[Figure 13] is a schematic diagram of chip removal at the lower section of the screw body when the present invention is actually used.

[Figure 14] is a schematic diagram of the first state of the middle section of the spiral body of the present invention.

[Figure 15] is a schematic diagram of the second state of the middle section of the spiral body of the present invention.

[Figure 16] is a schematic diagram of the third state of the middle section of the spiral body of the present invention.

[Figure 17] is a schematic diagram of the fourth state of the middle section of the spiral body of the present invention.

[Figure 18] is a schematic diagram of the fifth state of the middle section of the spiral body of the present invention.

[Figure 19] is a schematic diagram of the sixth state of the middle section of the spiral body of the present invention.

[Figure 20] is a schematic diagram of the first state of the upper part of the snail body of the present invention.

[Figure 21] is a schematic diagram of the second state of the upper part of the snail body of the present invention.

[Figure 22] is a schematic diagram of the third state of the upper part of the snail body of the present invention.

[Figure 23] is a schematic diagram of the fourth state of the upper part of the snail body of the present invention.

[Figure 24] is a schematic diagram of the fifth state of the upper part of the snail body of the present invention.

[Figure 25] is a schematic diagram of the sixth state of the upper part of the snail body of the present invention.

[Figure 26] is a schematic diagram of the first state of the screw head of the present invention.

[Figure 27] is a schematic diagram of the second state of the screw head of the present invention.

[Figure 28] is a schematic diagram of the third state of the screw head of the present invention.

[Figure 29] is a schematic diagram of the fourth state of the screw head of the present invention.

[Figure 30] is a schematic diagram of the fifth state of the screw head of the present invention.

In order to enable the review committee to have a deeper understanding and knowledge of the purpose, features and effects of this invention, please refer to the [Simple Diagram Description] for details as follows:

First, please refer to the first and second figures. 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). The lower screw body section (13) is concavely provided with at least one chip removal groove (131). As shown in the third to seventh figures, the chip removal groove (131) is provided with a chip removal groove (132). 31) gradually deepens from top to bottom, as shown in FIG. 8, and the chip removal groove (131) is inclined with respect to the central axis of the low resistance screw (10) at a chip removal angle (X), and the chip removal angle (X) is between 10 degrees and 20 degrees. As shown in FIG. 9, the chip removal groove (131) is divided into a flat first groove section (1311) and an inclined second groove section (1312), and the second groove section (1312) is inclined with respect to the radial direction. The tilt 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. As shown in the tenth and eleventh figures, the lower side of the chip removal groove (131) near the screw tail (14) is gradually reduced between the two side surfaces and has a drag reduction angle (Z). The drag reduction angle (Z) is between 15 degrees and 20 degrees to prevent debris from entering and leaving the chip removal groove. The groove (131) is over-extended and the resistance is increased when the screw is turned, thereby increasing the complete penetration ability during the screw rotation. The surface of the lower section (13) of the screw body and the screw tail (14) is provided with a spiral lower thread (101). The lower thread (101) and the chip removal 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 removal groove (131) is separated by the lower thread (101).

As shown in FIG. 12 and FIG. 13, when actually used, the tail (14) of the low-resistance screw (10) can be pressed against the object to be screwed, and the low-resistance screw (10) is rotated to screw in and the lower thread (101) is used to scrape and expand a hole (20) to achieve a self-tapping effect, so that the low-resistance screw (10) can be screwed on the object. Since the lower section (13) of the screw body is recessed with at least one chip removal groove (131) to reserve additional space, the lower thread (101) is provided with a hole (20) to form ... 1) The debris generated after planing can pass through the chip removal groove (131), thereby accelerating the speed and efficiency of the debris being discharged from the hole (20), and avoiding the accumulation of debris that affects the efficiency of self-tapping, and avoiding the accumulation of debris that collides with the low-resistance screw (10) and causes it to be skewed and affects the quality of screw fastening. The lower thread (101) is continuous and the chip removal groove (131) is separated by the lower thread (101), thereby avoiding the debris from being discharged in a non-helical direction and being blocked.

With the above structure, since the chip removal groove (131) is only recessed in the lower section (13) of the screw body and not located on the screw tail (14), the structure of the screw tail (14) is not damaged, and thus the structural strength is relatively strong, thereby preventing the screw tail (14) from breaking during processing and the screw tail (14) from breaking inside the hole (20) when the low resistance screw (10) is screwed out of the hole (20) in the future. Since the chip removal groove (131) gradually deepens from top to bottom, the closer to the bottom of the low resistance screw (10), the deeper the chip removal groove (131) is, thereby coping with the greater friction encountered by the front end of the low resistance screw (10) when self-tapping. The invention has a large resistance and can accommodate more debris, thereby improving the chip removal efficiency. 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, the chip removal efficiency is guaranteed while the structural strength of the lower section (13) of the screw body is ensured to avoid breakage and damage during processing or use. Moreover, since the chip removal groove (131) is inclined at a chip removal angle (X) relative to the central axis of the low resistance screw (10) and the lower thread (101) and the chip removal groove (131) are inclined in the same direction relative to the central axis of the low resistance screw (10), the debris can smoothly enter the chip removal groove (131), further improving the chip removal efficiency.

Furthermore, since the two side surfaces of the lower side of the chip removal groove (131) close to the screw tail (14) gradually contract and have the resistance reduction angle (Z), when the low resistance screw (10) begins to penetrate the target object, the bottom of the chip removal groove (131) is narrower to avoid the low resistance screw (10) from initially squeezing the debris in the chip removal groove (131) and causing the resistance to increase. At the same time, it can also prevent the low resistance screw (10) from shaking due to excessive resistance in the initial stage of screw rotation, thereby reducing the resistance and improving the complete penetration ability of the low resistance screw (10).

Therefore, the low-resistance screw (10) of the present invention improves chip removal efficiency while ensuring structural strength, which is of great benefit in use.

As shown in FIG. 8, the present invention provides a low-resistance anti-crack screw structure, wherein the tooth angle of the lower thread (101) is between 37 degrees and 43 degrees.

As shown in FIG. 9, the present invention provides a low resistance anti-crack 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.

As shown in the second figure, the present invention provides a low resistance anti-crack screw structure, wherein a spiral upper thread (102) is provided on the surface of the upper portion (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 positive and negative thread structure.

As shown in the eighth figure, the present invention provides a low resistance anti-crack screw structure, wherein the chip removal angle (X) is 15 degrees.

As shown in Figure 9, the present invention provides a low-resistance anti-crack screw structure, wherein the slope angle (Y) is 84 degrees.

As shown in Figures 10 and 11, the present invention provides a low-resistance anti-crack screw structure, wherein the drag reduction angle (Z) is 18 degrees.

The present invention provides a low resistance anti-crack screw structure, wherein both sides of the chip removal groove (131) are inclined, and the angle between the two sides of the chip removal groove (131) is 65 degrees. The inclination angle of one side of the chip removal groove (131) is 45 degrees and the inclination angle of the other side is 20 degrees. The chips can slide into the chip removal groove (131) from the larger inclination angle and accumulate from the smaller inclination angle.

The present invention provides a low resistance anti-crack 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.

As shown in Figures 14 to 19, they are schematic diagrams of different states of the middle section (12) of the screw body. Different functions and appearances are provided according to the state of the surface of the middle section (12) of the screw body.

From Figures 20 to 25, it is a schematic diagram of different states of the upper part (11) of the screw body, and different functions or rotation directions are provided according to the state of the upper thread (102).

The top of the low-resistance screw (10) has a screw head (15) for easy screwing. As shown in Figures 26 to 30, the screw head (15) has different functions according to its different state.

However, the above is only a preferred embodiment of the present invention and should not be used to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made according to the scope of the patent application of the present invention should still fall within the scope of the patent of the present invention.

(10): Low resistance screws

(101): Bottom thread

(12): Middle section of the snail body

(13): Lower part of the snail body

(131): Chip removal groove

(14):Snail tail

Claims (10)

A low-resistance anti-crack screw structure includes a low-resistance screw, which is divided from top to bottom into an upper screw body section, a middle screw body section, a lower screw body section and a conical screw tail, wherein: The lower section of the screw body is concavely provided with at least one chip removal groove, the chip removal groove gradually deepens from top to bottom, and the chip removal groove is inclined relative to the central axis of the low resistance screw at a chip removal angle, the chip removal 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 has an inclination angle relative to the radial inclination, the inclination 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 section of the screw body, and the chip removal groove is inclined relative to the radial inclination. The lower side of the chip groove near the screw tail gradually contracts between the two side surfaces and has a drag reduction angle. The drag reduction angle is between 15 and 20 degrees to prevent the chips from entering and leaving the chip groove and causing excessive extrusion and increasing resistance, thereby increasing the complete penetration ability during screw rotation. The lower section of the screw body and the surface of the screw tail are provided with a spiral lower thread. The lower thread and the chip groove have the same inclination direction relative to the central axis of the low resistance screw, and the lower thread is continuous so that the chip groove is separated by the lower thread. A low resistance anti-crack screw structure as described in claim 1, wherein the tooth angle of the lower thread is between 37 degrees and 43 degrees. A low resistance anti-crack screw structure as described in claim 1, wherein the depth of the first groove section is between 15% and 20% of the radius of the lower section of the screw body. As described in claim 1, the low resistance anti-crack screw structure, wherein the upper surface of the screw body is provided with a spiral upper thread, and the spiral direction of the upper thread is opposite to that of the lower thread. As described in claim 1, the low resistance anti-crack screw structure, wherein the chip removal angle is 15 degrees. The low resistance anti-crack screw structure as described in claim 1, wherein the slope angle is 84 degrees. The low resistance anti-crack screw structure as described in claim 1, wherein the drag reduction angle is 18 degrees. As described in claim 1, the low resistance anti-crack screw structure, wherein both side surfaces of the chip removal groove are inclined, and the angle between the two side surfaces of the chip removal groove is 65 degrees. A low resistance anti-crack screw structure as described in claim 8, wherein the inclination angle of one side of the chip removal groove is 45 degrees and the inclination angle of the other side is 20 degrees. A low resistance anti-crack screw structure as described in claim 1, wherein the maximum depth of the second groove section is between 40% and 55% of the radius of the lower section of the screw body.

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