Double-fastening explosive screw

Abstract

The utility model discloses a double-fastening explosive screw which comprises a screw rod, a sleeve, a first gasket and a nut, a pushing and pressing block is arranged at one end of the screw rod, and the screw rod is sleeved with the sleeve, the first gasket and the nut. The sleeve comprises a first positioning sleeve, expansion arms, a second positioning sleeve and expansion blades, the two opposite ends of each expansion arm are connected with the first positioning sleeve and the second positioning sleeve respectively, all the expansion arms are distributed around the axis of the first positioning sleeve, and the center of each expansion arm is bent towards the side away from the axis of the first positioning sleeve; one ends of the expansion blades are connected to the end, away from the first positioning sleeve, of the second positioning sleeve, all the expansion blades are distributed around the axis of the second positioning sleeve, the width of the expansion arms is smaller than that of the expansion blades, and limiting blocks are arranged on the sides, close to the center axis of the second positioning sleeve, of the expansion blades. The expansion arms and the expansion blades are combined, so that the double expansion fastening effect can be achieved, the anti-loosening and anti-falling performance is good, and the adaptability is high.

Description

Technical Field

[0001] The utility model relates to the field of hardware screw components, in particular to an explosion screw with double fastening. Background Art

[0002] An explosion screw, also known as an expansion screw or expansion bolt, is a special threaded connector, mainly including a countersunk head bolt, a sleeve, a washer and a nut. It uses a wedge-shaped slope to promote expansion to generate frictional gripping force, so as to achieve the fastening effect, and is mostly used in places such as walls and floors.

[0003] When using an explosion screw, first drill a corresponding installation hole in a target body such as a wall, then install the countersunk head bolt and the sleeve into the installation hole, and rotate the nut to drive the sleeve to expand through the countersunk head bolt. The combination of the screw and the nut mainly relies on the frictional force and pre-tightening force between the threads to achieve the fastening effect. The sleeve of the traditional explosion screw is provided with a gap on the side far from the nut to cooperate with the countersunk head bolt to achieve expansion. However, when applied to scenarios with high loads and high vibrations, the fastening structure of the existing explosion screw is unstable and prone to problems such as falling off. Summary of the Utility Model

[0004] The utility model aims to at least solve one of the technical problems existing in the prior art. For this purpose, the utility model provides an explosion screw with double fastening. The double-expansion structure can realize tight positioning in different regions, the fastening structure is stable and reliable, and the anti-falling-off performance is good.

[0005] An explosion screw with double fastening according to an embodiment of the utility model includes a screw rod, a sleeve, a first gasket and a nut. One end of the screw rod is provided with a pushing block. The sleeve, the first gasket and the nut are all sleeved outside the screw rod. The nut is threadedly connected to the end of the screw rod far from the pushing block. The nut and the sleeve are respectively located on opposite sides of the first gasket. The side of the pushing block close to the sleeve is provided with a pushing guide surface.

[0006] The sleeve includes a first positioning sleeve, expansion arms, a second positioning sleeve and expansion blades. The axes of the first positioning sleeve and the second positioning sleeve are collinear. There are at least two expansion arms and expansion blades. Opposite ends of each expansion arm are respectively connected to the first positioning sleeve and the second positioning sleeve. All the expansion arms are equidistantly distributed along a circumferential trajectory around the axis of the first positioning sleeve. The center of the expansion arm bends towards the side away from the axis of the first positioning sleeve. One end of the expansion blade is connected to the end of the second positioning sleeve far from the first positioning sleeve. All the expansion blades are equidistantly distributed along a circumferential trajectory around the axis of the second positioning sleeve. The width of the expansion arm is smaller than the width of the expansion blade. The pushing block is located on the side of the expansion blade far from the second positioning sleeve. A limiting block is provided on the side of the expansion blade close to the central axis of the second positioning sleeve.

[0007] In this embodiment, a plurality of positioning cone blocks are provided on the outer surface of each expansion blade. The positioning cone blocks are in the shape of cones or pyramids, and the cone bottoms of the positioning cone blocks are connected to the expansion blades.

[0008] In this embodiment, a clearance gap is formed between every two adjacent expansion blades, and a clearance hole is provided at one end of each clearance gap close to the second positioning sleeve, and the diameter of the clearance hole is greater than the width of the clearance gap.

[0009] In this embodiment, the pushing guide surface is an arc surface protruding close to the expansion blade.

[0010] In this embodiment, a positioning cone ring is provided on one side of the first gasket close to the first positioning sleeve, the ring diameter of the positioning cone ring narrows from the first gasket to the first positioning sleeve, and the end of the positioning cone ring away from the first gasket is inserted into the first positioning sleeve.

[0011] In this embodiment, a plurality of clearance grooves are provided on a side of the first positioning sleeve away from the expansion arm, and the length of the clearance grooves is smaller than the length of the first positioning sleeve.

[0012] In this embodiment, the double-fastened explosion screw also includes a second gasket, which is sleeved outside the screw rod and located between the first gasket and the nut.

[0013] In this embodiment, the nut is hexagonal.

[0014] The embodiments of the present invention have at least the following beneficial effects:

[0015] The effect of double expansion fastening can be formed by combining the expansion arms and the expansion blades. During the installation process of driving the nut to rotate relative to the screw, by setting the width of the expansion arms to be smaller than the width of the expansion blades and setting a limiting block to block the pressing block, the pressing block can first drive the second positioning sleeve close to the first positioning sleeve to squeeze the expansion arms. After the expansion arms are expanded to form the first fastening structure, the sleeve shortens. At this time, the structure of the expansion arms is stable and firm. Then, the pressing block continuously presses forward and inserts between the enclosures of each expansion blade, enabling the expansion blades to expand outward in all directions to form the second fastening structure. The double fastening structure can form a tight fastening effect with the installation hole wall. The fastening effect is stable and reliable, with good anti-loosening and anti-dropping performance, and can effectively adapt to complex application requirements such as high loads and high vibrations, with strong adaptability. By realizing the outward expansion of the expansion blades after the sleeve shortens, the wear between the expansion blades and the installation hole wall can be effectively reduced, and the expansion fastening action is stable and reliable. It can not only effectively ensure the integrity of the structure of the explosion screw, but also ensure the integrity of the installation hole structure, thereby effectively improving the tight fit degree and firmness of the formed fastening structure. In addition, by setting the center of the expansion arms to bend away from the central axis of the first positioning sleeve, a reliable bending guiding basis can be provided for the expansion arms, thereby effectively ensuring the reliability of the outward expansion action of the expansion arms, and at the same time, it can further ensure that the expansion arms expand and deform prior to the expansion blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present utility model will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

[0017] Figure 1 is a three-dimensional structural schematic diagram of the double-fastening explosion screw according to an embodiment of the present utility model;

[0018] Figure 2 is an exploded structural schematic diagram of the double-fastening explosion screw according to an embodiment of the present utility model;

[0019] Figure 3 is an internal structural schematic diagram of the double-fastening explosion screw before installation according to an embodiment of the present utility model;

[0020] Figure 4 is an internal structural schematic diagram of the double-fastening explosion screw after installation according to an embodiment of the present utility model.

[0021] REFERENCE NUMERALS:

[0022] Screw 100, Pressing Block 110, Pressing Guide Surface 111;

[0023] Sleeve 200, first positioning sleeve 210, relief cut 211, expansion arm 220, second positioning sleeve 230, expansion blade 240, limit block 241, positioning cone block 242, relief hole 250;

[0024] First gasket 300, positioning cone ring 310;

[0025] Nut 400;

[0026] Second gasket 500. Detailed implementation manner

[0027] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0028] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as up, down, left, right, front, back, etc. is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present utility model.

[0029] In the description of the present utility model, if the first and second are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence of the indicated technical features.

[0030] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installation, connection, etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0031] An explosion screw, also known as an expansion screw or expansion bolt, is a special threaded connector mainly including a countersunk head bolt, a sleeve, a washer and a nut. It uses a wedge-shaped slope to promote expansion to generate frictional gripping force, thereby achieving a fastening effect and is mostly used in places such as walls and floors.

[0032] When an explosive screw is used, first drill a corresponding installation hole in a target body such as a wall, and then insert a countersunk bolt and a sleeve into the installation hole. Rotating the nut can drive the sleeve to expand through the countersunk bolt, thereby achieving the effect of expansion and fastening. The combination of the screw and the nut mainly relies on the friction and pre-tightening force between the threads to achieve the fastening effect. The sleeve of the traditional explosive screw is provided with a slit on the side away from the nut to cooperate with the countersunk bolt to achieve expansion. However, when applied to scenarios such as high loads and high vibrations, such as in complex and harsh environments like mines and tunnels, the single fastening structure of the existing explosive screw is unstable. After withstanding high loads, large impacts, and strong vibrations, the explosive screw is difficult to maintain a long-term stable fastening effect and is prone to problems such as falling off, thus threatening the stability of the structure.

[0033] The following refers to the attached Figure 1 to the attached Figure 4 to describe the double-fastening explosive screw according to the embodiments of the present invention. The double-expansion structure can achieve tight positioning in different regions, and the fastening structure is stable and reliable, with good anti-falling performance.

[0034] Referring to Figures 1 to 4 , a double-fastening explosive screw according to an embodiment of the present invention includes a screw rod 100, a sleeve 200, a first gasket 300, and a nut 400. The first gasket 300 is in a circular ring shape. The outer diameters of the nut 400 and the first gasket 300 are both larger than the maximum outer diameter of the sleeve 200, and the inner diameter of the first gasket 300 is smaller than the minimum inner diameter of the sleeve 200. One end of the screw rod 100 is provided with a pressing block 110. The sleeve 200, the first gasket 300, and the nut 400 are all sleeved outside the screw rod 100. The nut 400 is specifically threadedly connected to one end of the screw rod 100 away from the pressing block 110. The nut 400 and the sleeve 200 are respectively located on opposite sides of the first gasket 300. The pressing block 110 is located on the side of the sleeve 200 away from the nut 400. A pressing guide surface 111 is provided on the side of the pressing block 110 close to the sleeve 200. The pressing guide surface 111 is used to guide the pressing block 110 to be pressed into the sleeve 200, which can effectively ensure the stability of the pressing and expanding action;

[0035] The sleeve 200 includes a first positioning sleeve 210, an expansion arm 220, a second positioning sleeve 230 and an expansion blade 240. The axis of the first positioning sleeve 210 and the axis of the second positioning sleeve 230 are collinear. There are at least two expansion arms 220 and expansion blades 240. The opposite ends of each expansion arm 220 are respectively connected to the first positioning sleeve 210 and the second positioning sleeve 230. All expansion arms 220 are evenly distributed along a circular trajectory around the axis of the first positioning sleeve 210. The spacing between each two adjacent expansion arms 220 is equal and non-zero, which can effectively ensure The outward expansion action of the expansion arm 220 can be carried out smoothly, and the center of the expansion arm 220 is bent toward the side away from the axis of the first positioning sleeve 210, that is, the distances between the two ends of the expansion arm 220 and the axis of the first positioning sleeve 210 are D1 and D2 respectively, and the distance between the center of the expansion arm 220 and the axis of the first positioning sleeve 210 is D3, D3>D1, and D3>D2. By setting the center of the expansion arm 220 to bend away from the axis of the first positioning sleeve 210, so that the expansion arm 220 forms a pre-bent structure, it can provide an original bend for the expansion action. The structure can effectively ensure that the expansion arm 220 is continuously bent in the direction away from the axis of the first positioning sleeve 210 during the extrusion process to form a supporting and tightening effect of expansion and expansion. One end of the expansion blade 240 is connected to the end of the second positioning sleeve 230 away from the first positioning sleeve 210. All the expansion blades 240 are evenly distributed along the circumferential trajectory around the axis of the second positioning sleeve 230. The spacing between each two adjacent expansion blades 240 is equal and non-zero, which can effectively ensure that the expansion and expansion action of the expansion blade 240 can be carried out smoothly. The width is smaller than that of the expansion blade 240, and the expansion arm 220 can be controlled to expand outward before the expansion blade 240. The pushing block 110 is located on the side of the expansion blade 240 away from the second positioning sleeve 230. The pushing block 110 is used to push to the area surrounded by all expansion blades 240 so that the expansion blade 240 bends outward to achieve the effect of expansion and tightening. A limit block 241 is provided on the side of the expansion blade 240 close to the central axis of the second positioning sleeve 230. The limit block 241 is used to cooperate with the pushing block 110 to push the second positioning sleeve 230 to move close to the first positioning sleeve 210.

[0036] The installation process of the utility model explosive screw is as follows: pre-drilling a through hole on the target body, inserting the sleeve 200 and the screw 100 into the through hole, and the structure before installation is as follows: Figure 3 As shown, the first gasket 300 and the nut 400 are located outside one side of the target body, and the push block 110 is located inside the target body. An electric screwdriver or other tool is used to limit the axial position of the nut 400 and drive the nut 400 to rotate. During the rotation of the nut 400 relative to the screw 100:

[0037] First, the pushing block 110 pushes the limiting block 241 to move closer to the first positioning sleeve 210. Since the width of the expansion arm 220 is smaller than the width of the expansion blade 240, and the limiting block 241 exerts a certain blocking effect on the pushing block 110, the pushing block 110 pushes the expansion blade 240 and the second positioning sleeve 230 to move synchronously closer to the first positioning sleeve 210 through the limiting block 241. The distance between the second positioning sleeve 230 and the first positioning sleeve 210 is continuously reduced, and the first positioning sleeve 210 and the second positioning sleeve 230 squeeze the expansion arm 220 between them. Since the expansion arm 220 has a pre-bent structure with the center deviating from the first positioning sleeve 210, the expansion arm 220 expands outward under the action of the squeezing force. During the outward expansion process, the overall length of the sleeve 200 is shortened, and the expansion blade 240 moves closer to the first positioning sleeve 210;

[0038] Then, after the expansion arm 220 completes the expansion and forms a stable structure, the limiting block 241 is not sufficient to continue blocking the advancement of the pushing block 110. The pushing block 110 is squeezed into the area surrounded by each expansion blade 240 and pushes the expansion blade 240 to expand outward. The structure before installation is referred to Figure 4 as shown. The expansion blade 240 expands outward to form a fastening structure, and the structure is stable and reliable.

[0039] By combining the expansion arms 220 and the expansion blades 240, a double-expansion fastening effect can be formed. During the installation process where the drive nut 400 rotates relative to the screw 100, by setting the width of the expansion arms 220 to be smaller than the width of the expansion blades 240, and setting the limit block 241 to block the push block 110, the push block 110 can first drive the second positioning sleeve 230 closer to the first positioning sleeve 210 to squeeze the expansion arms 220. After the expansion arms 220 complete expansion to form the first fastening structure, the sleeve 200 shortens. At this time, the structure of the expansion arms 220 is stable and firm. Then the push block 110 continuously pushes forward and inserts between the enclosures of each expansion blade 240, which can cause the expansion blades 240 to expand outwards in all directions to form the second fastening structure. The double fastening structure can form a tight abutting fastening effect with the installation hole wall. The fastening effect is stable and reliable, with good anti-loosening and anti-dropping performance, and can effectively adapt to complex application requirements such as high loads and high vibrations, with strong adaptability. By setting the expansion arms 220 to expand prior to the expansion blades 240, the reliability of the expansion fastening action can be effectively ensured. By realizing the outward expansion of the expansion blades 240 after the sleeve 200 shortens, the wear between the expansion blades 240 and the installation hole wall can be effectively reduced. The expansion fastening action is stable and reliable, which can not only effectively ensure the integrity of the explosion screw structure, but also ensure the integrity of the installation hole structure, thereby effectively improving the tight fit degree and firmness of the formed fastening structure. In addition, by setting the center of the expansion arms 220 to bend away from the central axis of the first positioning sleeve 210, a reliable bending guidance basis can be provided for the expansion arms 220, thereby effectively ensuring the reliability of the outward expansion action of the expansion arms 220, and at the same time further ensuring that the expansion arms 220 expand and deform prior to the expansion blades 240.

[0040] It can be understood that a number of positioning cone blocks 242 are provided on the outer surface of each expansion blade 240. All the positioning cone blocks 242 are evenly distributed. The positioning cone blocks 242 are conical or pyramid-shaped. The bottom of the cone of the positioning cone blocks 242 is connected to the expansion blade 240, and the top of the cone of the positioning cone blocks 242 is arranged away from the expansion blade 240. When the push block 110 pushes the expansion blade 240 to expand outwards, the positioning cone blocks 242 can be embedded into the hole wall of the installation hole, thereby effectively improving the position stability of the expansion blade 240 relative to the installation hole, effectively improving the firmness of the explosion screw fastening structure, and having a strong fastening load capacity.

[0041] It can be understood that a clearance gap is formed between every two adjacent expansion blades 240. A circular relief hole 250 is provided at one end of each clearance gap close to the second positioning sleeve 230. The diameter of the relief hole 250 is larger than the width of the clearance gap. By providing the relief hole 250, it can effectively provide clearance for the expansion and outward expansion movement of the expansion blade 240, enable the expansion deformation position of the expansion blade 240 to stop at the relief hole 250. The relief hole 250 can effectively buffer the bending and cracking effect caused by the expansion and outward expansion movement, and can effectively ensure the reliability of the overall structure of the sleeve 200.

[0042] It can be understood that the pushing guide surface 111 is a convex arc surface close to the expansion blade 240. After the pushing block 110 pushes the expansion blade 240 to expand through the pushing guide surface 111, the contact area between the expansion blade 240 and the mounting hole wall can be increased. The pushing and expanding effect of the pushing block 110 on the expansion blade 240 is good, and the stability of the fastening connection structure can be effectively improved.

[0043] It can be understood that a positioning cone ring 310 is provided on one side of the first gasket 300 close to the first positioning sleeve 210. The positioning cone ring 310 is a conical ring sleeve structure, and its outer surface and inner surface are both parts of a conical surface, having a good guiding and embedding effect. The ring diameter of the positioning cone ring 310 narrows axially from the first gasket 300 to the first positioning sleeve 210, and the thickness of each position of the positioning cone ring 310 is equal. One end of the positioning cone ring 310 away from the first gasket 300 is inserted into the first positioning sleeve 210. The positioning cone ring 310 can form a reliable guiding effect with the first positioning sleeve 210, and can effectively improve the stability of the installation and connection action.

[0044] It can be understood that a plurality of relief slots 211 are provided on one side of the first positioning sleeve 210 away from the expansion arm 220. The length of the relief slots 211 is less than the length of the first positioning sleeve 210. The relief slots 211 are used to form a plurality of petal structures on one side of the first positioning sleeve 210 close to the first gasket 300. When pressing the nut 400 against the target body, the positioning cone ring 310 is pressed into the first positioning sleeve 210, and under the relief action of the relief slots 211, one end of the first positioning sleeve 210 away from the expansion arm 220 expands outward in advance to form a stable structure, which can provide a stable installation basis for the subsequent double expansion and fastening action.

[0045] It can be understood that the double-fastening explosion screw further includes a second gasket 500. The second gasket 500 is sleeved outside the screw rod 100, and the second gasket 500 is located between the first gasket 300 and the nut 400. By means of the second gasket 500, the wear between the first gasket 300 and the nut 400 can be effectively reduced, and the stability of the overall structure of the explosion screw can be effectively improved.

[0046] Specifically, the second gasket 500 is a spring washer. Spring washers are widely used in the load-bearing and non-load-bearing structures of general mechanical products and have functions such as preventing loosening, increasing the pre-tightening force, and increasing the fastening contact area.

[0047] It can be understood that the nut 400 is hexagonal. By setting the outer contour of the nut 400 to be hexagonal, the contact area between the screwdriver bit and the nut 400 during rotary installation can be effectively increased, the damage to the nut 400 caused by the excessive concentration of the acting force during installation can be effectively avoided, and the stability of the installation operation can be effectively improved.

[0048] It can be understood that the nut 400 is a metal nut 400 and the sleeve 200 is a galvanized steel sleeve.

[0049] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A double-fastened explosive screw, characterized in that: The invention comprises a screw rod (100), a sleeve (200), a first gasket (300) and a nut (400), wherein a pushing block (110) is provided at one end of the screw rod (100), the sleeve (200), the first gasket (300) and the nut (400) are all sleeved outside the screw rod (100), the nut (400) is threadedly connected to an end of the screw rod (100) away from the pushing block (110), the nut (400) and the sleeve (200) are respectively located on two opposite sides of the first gasket (300), and a pushing guide surface (111) is provided on a side of the pushing block (110) close to the sleeve (200); The sleeve (200) comprises a first positioning sleeve (210), an expansion arm (220), a second positioning sleeve (230) and an expansion blade (240), wherein the axis of the first positioning sleeve (210) and the axis of the second positioning sleeve (230) are collinear, and at least two expansion arms (220) and at least two expansion blades (240) are provided, and opposite ends of each expansion arm (220) are respectively connected to the first positioning sleeve (210) and the second positioning sleeve (230), and all the expansion arms (220) are evenly spaced along a circular trajectory around the axis of the first positioning sleeve (210), and the center of the expansion arm (220) is away from the expansion blade (240). One side of the axis of the first positioning sleeve (210) is bent, one end of the expansion blade (240) is connected to the end of the second positioning sleeve (230) away from the first positioning sleeve (210), all the expansion blades (240) are evenly spaced along a circular trajectory around the axis of the second positioning sleeve (230), the width of the expansion arm (220) is smaller than the width of the expansion blade (240), the pushing block (110) is located on the side of the expansion blade (240) away from the second positioning sleeve (230), and a limit block (241) is provided on the side of the expansion blade (240) close to the central axis of the second positioning sleeve (230).

2. A double-fastened explosive screw according to claim 1, characterized in that: The outer surface of each expansion blade (240) is provided with a plurality of positioning cone blocks (242), the positioning cone blocks (242) are in the shape of a cone or a pyramid, and the cone bottom of the positioning cone block (242) is connected to the expansion blade (240).

3. A double-fastened explosive screw according to claim 1, characterized in that: A clearance gap is formed between each two adjacent expansion blades (240), and a clearance hole (250) is provided at one end of each clearance gap close to the second positioning sleeve (230), and the diameter of the clearance hole (250) is greater than the width of the clearance gap.

4. A double-fastened explosive screw according to claim 1, characterized in that: The pushing guide surface (111) is a circular arc surface protruding close to the expansion blade (240).

5. A double-fastened explosive screw according to claim 1, characterized in that: A positioning cone ring (310) is provided on one side of the first gasket (300) close to the first positioning sleeve (210), and the ring diameter of the positioning cone ring (310) narrows from the first gasket (300) to the first positioning sleeve (210), and one end of the positioning cone ring (310) away from the first gasket (300) is inserted into the first positioning sleeve (210).

6. A double-fastened explosive screw according to claim 5, characterized in that: A plurality of clearance grooves (211) are provided on a side of the first positioning sleeve (210) away from the expansion arm (220), and the length of the clearance grooves (211) is smaller than the length of the first positioning sleeve (210).

7. A double-fastened explosive screw according to claim 6, characterized in that: It also includes a second gasket (500), which is sleeved outside the screw rod (100), and the second gasket (500) is located between the first gasket (300) and the nut (400).

8. A double-fastened explosive screw according to claim 1, characterized in that: The nut (400) is hexagonal.

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