Expansion tube and expansion screw

Abstract

The utility model relates to a connecting piece, specifically an expansion tube and an expansion screw. The expansion tube includes a main body, one end of the main body is the front end, and the other end is the rear end, and an internal expansion channel is provided in the main body; the main body includes a first expansion segment and a second expansion segment along the axial direction, and the first expansion segment is located at the front end; the first expansion segment includes at least two expansion arms along the circumferential direction, and each two adjacent expansion arms are circumferentially disconnected; the second expansion segment includes an abutment portion and a deformation portion along the circumferential direction, and the number of the abutment portion and the deformation portion is equal, and there are at least two, and they are alternately distributed in the circumferential direction; the deformation portion is provided with a deformation groove; a constraint segment is provided between the first expansion segment and the second expansion segment, and the constraint segment is closed-loop arranged in the circumferential direction. The first expansion segment and the second expansion segment in the above-mentioned expansion tube can both expand to generate a connecting force, and have the advantage of reliable connection.

Description

Technical Field

[0001] The utility model relates to a connecting piece, in particular to an expansion tube and an expansion screw. Background Art

[0002] Expansion bolts are a type of threaded connector used to connect equipment on walls, floors, plates and other foundations. Compared with conventional bolts, expansion bolts include expansion tubes. When in use, by rotating the bolts, the bolts are screwed into the expansion tubes, and the expansion tubes can expand outwards and tighten with the openings on the foundation, so they have good connection reliability.

[0003] Common expansion bolts mainly include two forms. The first form is an expansion tube made of metal. When in use, the matching bolts are squeezed into the expansion tube in the form of a reduced diameter, forcing the expansion tube to permanently deform. It is usually used in occasions such as large equipment installation. The second form is an expansion tube made of elastic material, most commonly plastic. When in use, self-tapping screws are screwed into the expansion tube to squeeze the expansion tube to expand and deform outward. It is often used for the installation and connection of small items at work or in life. The expansion tube described in this application belongs to the second form of expansion tube made of elastic material.

[0004] The Chinese utility model patent with authorization announcement number CN 214499693U previously submitted by the applicant discloses an anti-pullout expansion bolt, including a rod body, on which two expansion arms are formed by setting expansion cracks. When in use, the bolt is screwed into the hole to squeeze the two expansion arms to expand outward. The above expansion bolt is only provided with a pair of expansion arms to achieve unidirectional outward expansion and tightening. There is only one set of radial expansion components in the axial direction. When the length-diameter ratio of the expansion bolt is large, the connection force generated by the single set of expansion components has a certain degree of unreliability. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide an expansion pipe and an expansion screw, wherein both the first expansion segment and the second expansion segment can expand to generate a connection force, and the utility model has the advantage of reliable connection.

[0006] In order to solve the above technical problems, the utility model provides the following technical solutions: an expansion tube, comprising a main body, one end of the main body is a front end, the other end is a rear end, an internal expansion channel is provided in the main body, and the internal expansion channel is provided through the main body along the axial direction;

[0007] The main body includes a first expansion segment and a second expansion segment along the axial direction, and the first expansion segment is located at the front end; the first expansion segment includes at least two expansion arms along the circumferential direction, and each adjacent two expansion arms are circumferentially disconnected;

[0008] The second expansion segment includes an abutment portion and a deformation portion along the circumferential direction. The abutment portion and the deformation portion are equal in number and at least two and are alternately distributed in the circumferential direction. The deformation portion is provided with a deformation groove.

[0009] A constraint segment is provided between the first expansion segment and the second expansion segment, and the constraint segment is arranged in a closed loop in the circumferential direction.

[0010] When the matching internal expansion screw is screwed into the internal expansion channel, the two expansion arms of the first expansion segment are disconnected in the circumferential direction. Under the action of the internal expansion force, the two expansion arms expand outward, and the second expansion segment also expands outward due to the setting of the deformation groove. The constraint segment is closed in the circumference, and the degree of outward deformation is much smaller than that of the first expansion segment and the second expansion segment.

[0011] The first expansion segment and the second expansion segment expand separately and form stress points respectively, so that the connection force is more evenly distributed in the axial direction, which can improve the reliability of the connection and is particularly suitable for bolts with a large length-to-diameter ratio. At the same time, the first expansion segment and the second expansion segment are disconnected under the constraint segment separation, which can avoid a single expansion segment being too long, and the overall strength of the expansion pipe is higher, and the axial distribution of the tightening force is more reasonable.

[0012] Preferably, a plurality of annular grooves are distributed on the outer side of the second expansion segment, and the depth of the annular grooves in the segment corresponding to the abutment portion is smaller than the depth of the segment corresponding to the deformation portion.

[0013] The provision of the annular groove can guide the expansion deformation of the expansion tube. Meanwhile, the provision of the deformation groove can also make the surface of the expansion tube rougher, increase the surface friction, and thus improve the reliability of the connection.

[0014] Preferably, the deformation groove is at least partially inclined relative to the center line of the main body to provide a space for the expansion of the second expansion segment.

[0015] Preferably, a plurality of pressing protrusions are provided on the outer side of the abutting portion, and the pressing protrusions on each abutting portion are arranged in one-to-one correspondence.

[0016] When the expansion tube is expanded outwardly for connection, the arrangement of the clamping protrusion can increase the clamping force and improve the connection reliability.

[0017] Preferably, each of the abutting portions is provided with at least two clamping protrusions, and the clamping protrusions are disconnected from each other in the axial direction.

[0018] The distribution position of the clamping bumps corresponds to the distribution position of the peak value of the tightening force. When the length-to-diameter ratio of the expansion tube is relatively large, the clamping bumps are arranged in sections in the axial direction. Correspondingly, multiple peak points of the tightening force can be formed along the axial direction. The tightening force is distributed in stages to ensure the reliability of the connection.

[0019] Preferably, the number of the abutting portions and the number of the deformation portions are both two, the two abutting portions are arranged opposite to each other, and the two deformation portions are arranged opposite to each other; and the radial distance between the two deformation portions is smaller than the radial distance between the two abutting portions.

[0020] When the matching internal expansion screw is screwed in, the distance between the two deformation parts is small, and the corresponding two deformation parts are deformed outward to a greater extent. Under the guidance of the deformation groove, the second expansion segment can fully expand and deform, thereby stabilizing the connection. At the same time, since the distance between the two deformation parts is small, the thickness of the corresponding deformation part is greater than the abutment part. After the deformation part is fully deformed, the strength difference between the deformation part and the abutment part can still be guaranteed to be within a reasonable range.

[0021] Preferably, the main body further comprises a guide segment, the guide segment is located at the rear end, the internal expansion channel comprises a guide segment and an expansion segment, wherein the guide segment corresponds to the guide segment; the cross section of the guide segment is larger than the cross section of the expansion segment. The setting of the guide segment can play a good guiding role for the insertion of the matching internal expansion screw.

[0022] Preferably, a retaining ring protruding outward is provided at the rear end of the main body, and the retaining ring can play a role in end positioning.

[0023] An expansion screw comprises an expansion tube and an internal expansion screw, wherein the expansion tube is the expansion tube as described above.

[0024] Preferably, the internal expansion screw is provided with screw threads, and the screw threads include a first segment and a second segment along the axial direction, and the first segment is arranged close to the tip of the internal expansion screw; the pitch of the first segment is greater than the pitch of the second segment.

[0025] The first segment has a larger pitch, and the corresponding driving force required for drilling is smaller, which is convenient for drilling the tip of the internal expansion screw. The second segment has a smaller pitch, and the corresponding thread distribution is more dense, which has a better effect on the expansion tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the expansion tube of this embodiment;

[0027] Figure 2 It is a front view of one side of the expansion tube of this embodiment;

[0028] Figure 3 It is a front view of the other side of the expansion tube of this embodiment;

[0029] Figure 4 for Figure 3 Middle AA section view;

[0030] Figure 5 for Figure 3 Middle BB section view;

[0031] Figure 6 for Figure 3 Middle CC section view;

[0032] Figure 7 It is a schematic diagram of the structure of the internal expansion screw in the expansion screw of this embodiment. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model. Example

[0034] like Figure 1 and Figure 4 As shown, an expansion tube includes a main body, one end of the main body is a front end 7, and the other end is a rear end 6. An internal expansion channel 8 is provided in the main body, and the internal expansion channel 8 is arranged to penetrate the main body along the axial direction.

[0035] like Figure 1-Figure 3 As shown, the main body includes a first expansion segment 1 and a second expansion segment 3 along the axial direction, and the first expansion segment 1 is located at the front end 7. Figure 5 As shown, the first expansion segment 1 includes at least two expansion arms 11 along the circumferential direction, and each two adjacent expansion arms 11 are circumferentially disconnected.

[0036] like Figure 2 , Figure 3 and Figure 6 As shown, the second expansion segment 3 includes abutment portions 32 and deformation portions 34 along the circumferential direction. The number of the abutment portions 32 and the deformation portions 34 is equal, and there are at least two of them, and they are alternately distributed in the circumferential direction.

[0037] like Figure 1 and Figure 3 As shown, the deformation portion 34 is provided with a deformation groove 33 , and the deformation groove 33 is arranged to penetrate the deformation portion 34 . The deformation groove 33 is at least partially arranged to be inclined relative to the center line of the main body, so as to provide an interval for the expansion of the second expansion segment 3 .

[0038] like Figure 1-Figure 3 As shown, a constraint segment 2 is provided between the first expansion segment 1 and the second expansion segment 3, and the constraint segment 2 is arranged in a closed loop in the circumferential direction.

[0039] When the matching internal expansion screw is screwed into the internal expansion channel 8, the two expansion arms 11 of the first expansion segment 1 are disconnected in the circumferential direction, and the two expansion arms expand outward under the action of the internal expansion force, and the second expansion segment 3 also expands outward due to the setting of the deformation groove 33. The constraint segment 2 is closed in the circumferential direction, and the degree of outward deformation is much smaller than that of the first expansion segment 1 and the second expansion segment 3.

[0040] The first expansion segment 1 and the second expansion segment 3 expand separately and form stress points respectively, so that the connection force is more evenly distributed in the axial direction, which can improve the reliability of the connection and is particularly suitable for bolts with a large length-to-diameter ratio. At the same time, the first expansion segment 1 and the second expansion segment 3 are separated by the constraint segment 2, which can avoid a single expansion segment being too long, and the overall strength of the expansion pipe is higher, and the axial distribution of the tightening force is more reasonable.

[0041] At the same time, since the first expansion segment 1 is arranged at the front end 7 of the main body, that is, one end of the expansion arm is a free end, it can expand freely outward after the matching internal expansion screw 9 is screwed in, ensuring reliable expansion of the front end 7. In order to ensure the expansion effect of the first expansion segment 1, the length of the first expansion segment 1 is 0.1-0.2 times the length of the main body.

[0042] like Figure 1-Figure 3 As shown, specifically, a plurality of annular grooves are distributed on the outer side of the second expansion segment 3, and the depth of the annular groove corresponding to the abutment portion 32 is less than the depth of the segment corresponding to the deformation portion 34. The provision of the annular groove can guide the expansion deformation of the expansion tube, and the provision of the deformation groove 33 can also make the surface of the expansion tube rougher, increase the surface friction, and thus improve the reliability of the connection.

[0043] like Figure 2 As shown, specifically, a plurality of pressing protrusions 31 are provided on the outer side of the abutting portion 32, and the pressing protrusions 31 on each abutting portion 32 are provided one by one. When the expansion tube is expanded outwardly for connection, the provision of the pressing protrusions 31 can increase the pressing force and improve the connection reliability.

[0044] like Figure 2 As shown, further, each of the abutting portions 32 is provided with at least two clamping protrusions 31, and each of the clamping protrusions 31 is arranged in a disconnected manner in the axial direction. The distribution position of the clamping protrusions 31 corresponds to the distribution position of the peak value of the expansion force. When the aspect ratio of the expansion tube is relatively large, the clamping protrusions 31 are arranged in sections in the axial direction, and correspondingly, multiple peak points of the expansion force can be formed in the axial direction, and the expansion force is distributed in a stepwise manner to ensure the reliability of the connection.

[0045] like Figure 6As shown, specifically, the number of the abutting portions 32 and the number of the deforming portions 34 are both two, the two abutting portions 32 are arranged opposite to each other, and the two deforming portions 34 are arranged, and the radial distance between the two deforming portions 34 is smaller than the radial distance between the two abutting portions 32 .

[0046] When the matching internal expansion screw 9 is screwed in, the distance between the two deformation parts 34 is small, and the corresponding two deformation parts 34 are deformed outward to a greater extent. Under the guidance of the deformation groove 33, the second expansion segment 3 can be fully expanded and deformed, thereby stabilizing the connection. At the same time, since the distance between the two deformation parts 34 is small, the thickness of the corresponding deformation part 34 is greater than the abutment part 32. After the deformation part 34 is fully deformed, the strength difference between the deformation part 34 and the abutment part 32 can still be guaranteed to be within a reasonable range.

[0047] like Figure 1 and Figure 4 As shown, specifically, the main body further includes a guide segment 4, the guide segment 4 is located at the rear end 6, and the internal expansion channel 8 includes a guide segment 81 and an expansion segment 82, wherein the guide segment 81 corresponds to the guide segment 4. The cross section of the guide segment 81 is larger than the cross section of the expansion segment 82. The setting of the guide segment 4 can play a good guiding role for the insertion of the matching internal expansion screw 9. The rear end 6 of the main body is provided with a retaining ring 5 protruding outward, which can play a role in end positioning.

[0048] An expansion screw comprises an expansion tube and an internal expansion screw 9, wherein the expansion tube is the expansion tube as described above.

[0049] like Figure 7 As shown, specifically, the internal expansion screw 9 is provided with screw threads, and the screw threads include a first segment 92 and a second segment 91 along the axial direction, the first segment 92 is arranged close to the tip of the internal expansion screw 9, and the pitch of the first segment 92 is greater than the pitch of the second segment 91. Specifically, the first segment 92 adopts a single-line screw thread, and the second segment 91 adopts a bidirectional screw thread, and the screw thread lead of the first segment 92 and the second segment 91 is the same.

[0050] The first segment 92 has a larger pitch, and the corresponding driving force required for drilling is smaller, which facilitates the drilling of the tip of the internal expansion screw 9. The second segment 91 has a smaller pitch, and the corresponding thread distribution is more dense, and the thread has a better effect on the expansion tube.

[0051] Specifically, the thread shape of the screw is oblate, and the screwing depth of the oblate screw is smaller, while the bearing capacity is stronger, and the expansion tube can be better supported.

[0052] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An expansion pipe, comprising a main body, one end of the main body being a front end and the other end being a rear end, an internal expansion channel being arranged in the main body, and the internal expansion channel being arranged to penetrate the main body along the axial direction; Features: The main body includes a first expansion segment and a second expansion segment along the axial direction, and the first expansion segment is located at the front end; the first expansion segment includes at least two expansion arms along the circumferential direction, and each adjacent two expansion arms are circumferentially disconnected; The second expansion segment includes an abutment portion and a deformation portion along the circumferential direction. The abutment portion and the deformation portion are equal in number and at least two and are alternately distributed in the circumferential direction. The deformation portion is provided with a deformation groove. A constraint segment is provided between the first expansion segment and the second expansion segment, and the constraint segment is arranged in a closed loop in the circumferential direction.

2. The expandable tube according to claim 1, characterized in that: A plurality of annular grooves are distributed on the outer side of the second expansion segment, and the depth of the annular groove in the segment corresponding to the abutment portion is smaller than the depth of the segment corresponding to the deformation portion.

3. The expandable tube according to claim 1, characterized in that: At least part of the deformation groove is arranged obliquely relative to the center line of the main body.

4. The expandable tube according to claim 1, characterized in that: A plurality of pressing protrusions are arranged on the outer side of the abutting portion, and the pressing protrusions on each abutting portion are arranged in a one-to-one correspondence.

5. The expandable tube according to claim 4, characterized in that: Each of the abutting portions is provided with at least two pressing protrusions, and the pressing protrusions are separated from each other in the axial direction.

6. The expandable tube according to any one of claims 1 to 5, characterized in that: The number of the abutting parts and the number of the deformation parts are both two, the two abutting parts are arranged opposite to each other, and the two deformation parts are arranged opposite to each other; the radial distance between the two deformation parts is smaller than the radial distance between the two abutting parts.

7. The expandable tube according to claim 6, characterized in that: The main body also includes a guide segment, which is located at the rear end. The internal expansion channel includes a guide segment and an expansion segment, wherein the guide segment corresponds to the guide segment; the cross section of the guide segment is larger than the cross section of the expansion segment.

8. The expandable tube according to claim 7, characterized in that: A retaining ring protruding outwards is arranged at the rear end of the main body.

9. An expansion screw, comprising an expansion tube and an internal expansion screw, characterized in that: The expansion tube is the expansion tube as described in any one of claims 1-8.

10. The expansion screw according to claim 9, characterized in that: The internal expansion screw is provided with screw threads, and the screw threads include a first segment and a second segment along the axial direction, the first segment is arranged close to the tip of the internal expansion screw; the pitch of the first segment is greater than the pitch of the second segment.

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