Tapered core rod tensioning plug

Abstract

The utility model provides a conical core rod pulling and expanding plug, which comprises a core rod and a sleeve, the core rod comprises a large round surface, a conical section and a small round surface which are sequentially arranged from one end to the other end, the outer diameter of the conical section is gradually reduced from one end to the other end, the center of the small round surface is axially provided with an inner threaded hole, the sleeve is sleeved on the outer side of the core rod, and the sleeve is cylindrical. The sleeve comprises a sleeve outer wall on the outer side and a hollow part on the inner side, the sleeve outer wall is tightly matched with the inner wall of the mounting hole, and the interference magnitude of the conical section to the inner side of the sleeve from the small circular surface to the large circular surface is sequentially increased; the taper angle is designed on the outer wall of the core rod of the tension plug, and the taper angle can be selectively designed on the inner wall of the sleeve, so that the taper angle of the central section of the inner surface of the sleeve is smaller than the taper angle of the central section of the outer wall of the core rod, the uniformity of extrusion deformation of the inner wall of the sleeve in the movement process of the core rod is improved, and the sealing reliability of the tension plug is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile process hole sealing, in particular to a conical core rod expanding plug. Background Art

[0002] Most of the existing automobile industrial process hole sealing technologies use expanding plugs, and the installation steps are as follows: Assemble the expanding plug into the tool gun, assemble the gun head of the tool gun and the plug into the corresponding installation hole of the part to be sealed, the tool gun head pulls the plug core rod, the core rod moves into the inside of the sleeve, the core rod squeezes the sleeve, the outer wall of the sleeve and the inner wall of the installation hole of the sealed part are interference-fitted or the sleeve sealing ring is extruded into the sealed part, and then the tool gun is withdrawn.

[0003] In this process, it is required that the surface hardness and roundness of the used core rod and sleeve meet the standards, the hardness of the metal contact surface between the sealing hole and the sleeve is slightly lower than the surface hardness of the sleeve, at the same time, the roundness of the contact surface should be ensured, and it should be a surface contact as much as possible. The complete surface-to-surface contact of the sleeve with the contact surface realizes the sealing. The hardness of the contact surface between the sleeve and the core rod is slightly lower than the surface hardness of the core rod, and the surface-to-surface contact is ensured by the extrusion of the contact surface between the core rod and the sleeve to realize the sealing of the two.

[0004] Since the core rod and the sleeve generally adopt a cylindrical design, after the physical sealed part is sectioned and assembled with the expanding plug, the depths of the respective sealing grooves generated by the interference extrusion of the outer wall of the sleeve on the inner wall of the installation hole are uneven, affecting the sealing reliability. Summary of the Invention

[0005] The purpose of the utility model is to provide a conical core rod expanding plug, which improves the sealing reliability of the expanding plug by improving the cone angle based on the existing cylindrical core rod and sleeve surfaces.

[0006] In order to achieve the above purpose, the technical solution of the utility model is as follows:

[0007] A conical core rod expanding plug, characterized in that it includes a core rod and a sleeve. The core rod includes a large circular surface, a conical section and a small circular surface arranged in sequence from one end to the other end. The outer diameter of the conical section gradually decreases from one end to the other end. An internal threaded hole is axially provided at the center of the small circular surface. The sleeve is sleeved outside the core rod. The sleeve is cylindrical. The sleeve includes an outer sleeve wall outside and a hollowed-out part inside. The outer sleeve wall is in close fit with the inner wall of the installation hole. The large circular surface, the conical section and the small circular surface are all in interference fit with the inside of the sleeve.

[0008] Further, a plurality of outer annular sealing grooves are arranged on the outer sleeve wall along the circumferential direction. The outer annular sealing grooves are arranged in a toothed pattern. The outer sleeve wall is in close fit with the inner wall of the installation hole through the outer annular sealing grooves.

[0009] Furthermore, a plurality of inner annular sealing grooves are provided on the conical section. The inner annular sealing grooves are arranged in a toothed pattern, and the conical section is in close fit with the inner wall of the hollowed-out part through the inner annular sealing grooves.

[0010] Furthermore, the inclination directions of the inner annular sealing grooves and the annular sealing grooves are opposite.

[0011] Furthermore, an arc chamfer is provided at the outer edge of the small circular surface.

[0012] Furthermore, the large circular surface is convex outward in an arc shape from the outer periphery to the axis.

[0013] Furthermore, the core rod further includes a flange. The outer diameter of the flange is larger than the outer diameter of the large circular surface, and the flange is integrally formed with one end of the large circular surface.

[0014] A conical core rod expanding plug, characterized in that it includes a core rod and a sleeve. The core rod includes a large circular surface, a conical section, and a small circular surface sequentially arranged from one end to the other end. The outer diameter of the conical section gradually decreases from one end to the other end. An internal threaded hole is provided axially in the center of the small circular surface. The sleeve is sleeved outside the core rod. The sleeve includes a sleeve outer wall on the outside and a hollowed-out part on the inside. The inner diameter of the hollowed-out part gradually decreases from one end to the other end. The sleeve outer wall is in close fit with the inner wall of the installation hole, and the large circular surface, the conical section, and the small circular surface are all in interference fit with the inner wall of the sleeve.

[0015] A conical core rod expanding plug, characterized in that it includes a core rod and a sleeve. The core rod includes a large circular surface, a cylindrical section, a conical section, and a small circular surface sequentially arranged from one end to the other end. The outer diameter of the conical section gradually decreases from one end to the other end. An internal threaded hole is provided axially in the center of the small circular surface. The sleeve is sleeved outside the core rod. The sleeve is in a cylindrical shape. The sleeve includes a sleeve outer wall on the outside and a hollowed-out part on the inside. The sleeve outer wall is in close fit with the inner wall of the installation hole, and the large circular surface, the cylindrical section, the conical section, and the small circular surface are all in interference fit with the inside of the sleeve.

[0016] In the present utility model, a taper angle is designed on the outer wall of the core rod of the expanding plug, and a taper angle can be optionally designed on the inner wall of the sleeve, ensuring that the central section taper angle of the inner surface of the sleeve is smaller than the central section taper angle of the outer wall of the core rod, improving the uniformity of the extrusion deformation suffered by the inner wall of the sleeve during the movement of the core rod, and improving the sealing reliability of the expanding plug. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1;

[0018] Figure 2 It is a schematic diagram of the installation of Embodiment 1 in the part installation hole;

[0019] Figure 3Schematic diagram of the overall structure of Example 2;

[0020] Figure 4 Schematic diagram of the installation of Example 2 in the part mounting hole;

[0021] Figure 5 Schematic diagram of the overall structure of Example 3;

[0022] Figure 6 Schematic diagram of the installation of Example 3 in the part mounting hole;

[0023] Figure 7 Schematic diagram of the overall structure of Example 4;

[0024] Figure 8 Schematic diagram of the installation of Example 4 in the part mounting hole;

[0025] Figure 9 Schematic diagram of the overall structure of Example 5;

[0026] Figure 10 Schematic diagram of the installation of Example 5 in the part mounting hole;

[0027] Figure 11 Schematic diagram of the overall structure of Example 6;

[0028] Figure 12 Schematic diagram of the installation of Example 6 in the part mounting hole.

[0029] Reference numerals:

[0030] 1 mandrel, 11 large circular surface, 12 conical section, 121 inner annular sealing groove, 13 small circular surface,

[0031] 14 internal threaded hole, 15 flange, 16 cylindrical section,

[0032] 2 sleeve, 21 sleeve outer wall, 22 hollowed-out part, 23 outer annular sealing groove,

[0033] 3 mounting hole. Detailed implementation manners

[0034] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Example 1

[0035] This example discloses a tapered mandrel expansion plug, as Figure 1 and Figure 2As shown in the figure, it includes a core rod 1 and a sleeve 2. The core rod 1 includes a large circular surface 11, a conical section 12, and a small circular surface 13 arranged in sequence from one end to the other end. The outer diameter of the conical section 12 gradually decreases from one end to the other end. An internal threaded hole 14 is axially provided at the center of the small circular surface 13.

[0036] The sleeve 2 is sleeved on the outside of the core rod 1. The sleeve 2 is cylindrical. The sleeve 2 includes a sleeve outer wall 21 on the outside and a hollowed-out part 22 on the inside. The sleeve outer wall 21 is in close fit with the inner wall of the mounting hole 3. The large circular surface 11, the conical section 12, and the small circular surface 13 are all in interference fit with the inside of the sleeve 2.

[0037] A number of outer annular sealing grooves 23 are provided on the sleeve outer wall 21 along the circumferential direction. The outer annular sealing grooves 23 are arranged in a toothed pattern. The sleeve outer wall 21 is in close fit with the inner wall of the mounting hole 3 through the outer annular sealing grooves 23. When the core rod 1 squeezes the sleeve 2, the outer annular sealing grooves 23 with a toothed structure on the outer wall of the sleeve 2 are squeezed and embedded into the part mounting hole 3 to achieve a better sealing effect.

[0038] Preferably, the inclination direction of the outer annular sealing groove 23 is the same as the installation direction of the sleeve 2 in the mounting hole 3, and the sleeve 2 is easy to enter the mounting hole 3 and not easy to withdraw. Embodiment 2

[0039] This embodiment discloses a tapered core rod expansion plug, as shown in Figure 3 and Figure 4 As shown, it includes a core rod 1 and a sleeve 2. The structure of the sleeve 2 in this embodiment is the same as that in Embodiment 1. The difference is that a number of inner annular sealing grooves 121 are provided on the conical section 12 of the core rod 1, and the conical section 12 is in close fit with the hollowed-out part 22 through the inner annular sealing grooves 121.

[0040] Preferably, the inclination directions of the inner annular sealing groove 121 and the outer annular sealing groove 23 are opposite, that is, the inclination direction of the inner annular sealing groove 121 is the same as the retraction direction of the core rod 1. The core rod 1 is easy to retract into the sleeve 2 and not easy to escape.

[0041] In Embodiment 1 and Embodiment 2, the sleeve outer wall 21 can also be changed to a smooth structure without teeth. Embodiment 3

[0042] This embodiment discloses a tapered core rod expansion plug, as shown in Figure 5 and Figure 6 As shown, it includes a core rod 1 and a sleeve 2. The core rod 1 includes a large circular surface 11, a conical section 12, and a small circular surface 13 arranged in sequence from one end to the other end. The large circular surface 11 is convex outward in an arc shape from the outer circumference to the axis. The arc-shaped large circular surface 11 has a greater thickness compared to the flat hole bottom. The outer diameter of the conical section 12 gradually decreases from one end to the other end. An internal threaded hole 14 is axially provided at the center of the small circular surface 13.

[0043] The sleeve 2 is sleeved on the outside of the core rod 1. The sleeve 2 is cylindrical, including the outer sleeve outer wall 21 and the inner hollowed-out part 22. The sleeve outer wall 21 is in close fit with the inner wall of the mounting hole 3, and the large circular surface 11, the conical section 12, and the small circular surface 13 are all in interference fit with the inside of the sleeve 2.

[0044] In this embodiment, the outer wall of the sleeve 21 and the outer wall of the conical section 12 are preferably smooth structures without teeth.

[0045] In this embodiment, the core rod 1 has a deeper threaded hole depth, which can maintain the assembly reliability of the core rod in the application of parts with higher hardness. The increase in the wall thickness at the bottom of the threaded hole of the core rod can also improve the qualified rate of the airtightness of the expansion plug. Embodiment 4

[0046] This embodiment discloses a conical core rod expansion plug, as Figure 7 and Figure 8 shown, including a core rod 1 and a sleeve 2. The core rod 1 includes a flange 15, a large circular surface 11, a conical section 12, and a small circular surface 13 arranged in sequence from one end to the other end. The outer diameter of the flange 15 is greater than the outer diameter of the large circular surface 11, and the flange 15 and the large circular surface 11 are integrally formed. The outer diameter of the conical section 12 gradually decreases from one end to the other end, and an internal threaded hole 14 is axially provided at the center of the small circular surface 13.

[0047] The sleeve 2 is sleeved on the outside of the core rod 1. The sleeve 2 is cylindrical, including the outer sleeve outer wall 21 and the inner hollowed-out part 22. The sleeve outer wall 21 is in close fit with the inner wall of the mounting hole 3, and the large circular surface 11, the conical section 12, and the small circular surface 13 are all in interference fit with the inside of the sleeve 2.

[0048] A number of outer annular sealing grooves 23 are provided on the sleeve outer wall 21 along the circumferential direction. The outer annular sealing grooves 23 are arranged in a toothed pattern. The sleeve outer wall 21 is in close fit with the inner wall of the mounting hole 3 through the outer annular sealing grooves 23. When the core rod 1 presses the sleeve 2, the outer annular sealing grooves 23 with a toothed structure on the outer wall of the sleeve 2 are pressed and embedded into the part mounting hole 3 to achieve a better sealing effect. The end face of the flange 15 stops the end face of the sleeve 2 and prevents the core rod 1 from continuing to enter the sleeve 2.

[0049] In this embodiment, the core rod 1 has a deeper threaded hole depth, which can maintain the assembly reliability of the core rod in the application of parts with higher hardness. The increase in the wall thickness at the bottom of the threaded hole of the core rod can also improve the qualified rate of the airtightness of the expansion plug.

[0050] In this embodiment, the conical section 12 of the core rod 1 is preferably provided with a number of inner annular sealing grooves 121, and the conical section 12 can also be changed to a smooth structure without teeth. Embodiment 5

[0051] This embodiment discloses a conical core rod expansion plug, asFigure 9 and Figure 10 As shown in and

[0052] , it includes a core rod 1 and a sleeve 2. The core rod 1 includes a large circular surface 11, a conical section 12, and a small circular surface 13 arranged in sequence from one end to the other end. The outer diameter of the conical section 12 gradually decreases from one end to the other end, and an internal threaded hole 14 is axially provided at the center of the small circular surface 13.

[0052] The sleeve 2 is sleeved outside the core rod 1. The sleeve 2 includes an outer sleeve wall 21 on the outside and a hollowed-out part 22 on the inside. The inner diameter of the hollowed-out part 22 gradually decreases from one end to the other end. The outer sleeve wall 21 is in close fit with the inner wall of the mounting hole 3, and the large circular surface 11, the conical section 12, and the small circular surface 13 are all in interference fit with the hollowed-out part 22.

[0053] In this embodiment, the outer sleeve wall 21 and the outer wall of the conical section 12 are preferably smooth structures without teeth. The outer sleeve wall 21 can also be provided with an outer annular sealing groove 23 in the circumferential direction. Embodiment 6

[0054] This embodiment discloses a tapered core rod expanding plug. As shown in Figure 11 and Figure 12 , it includes a core rod 1 and a sleeve 2. The core rod 1 includes a large circular surface 11, a cylindrical section 16, a conical section 12, and a small circular surface 13 arranged in sequence from one end to the other end. The outer diameter of the conical section 12 gradually decreases from one end to the other end, and an internal threaded hole 14 is axially provided at the center of the small circular surface 13. Figure 11 and Figure 12 The sleeve 2 is sleeved outside the core rod 1. The sleeve 2 is cylindrical. The sleeve 2 includes an outer sleeve wall 21 on the outside and a hollowed-out part 22 on the inside. The outer sleeve wall 21 is in close fit with the inner wall of the mounting hole 3, and the large circular surface 11, the cylindrical section 16, the conical section 12, and the small circular surface 13 are all in interference fit with the inside of the sleeve 2.

[0055] In this embodiment, the connection between the conical section 12 and the cylindrical section 16 of the core rod 1 has a smooth transition. The conical section 12 first comes into extrusion contact with the hollowed-out part 22 inside the sleeve 2, and the cylindrical section 16 then comes into extrusion contact with the hollowed-out part 22. The design of the cylindrical section 16 can exert the maximum extrusion effect on the hollowed-out part 22 inside the sleeve 2, improving the sealing reliability of the plug.

[0056] The existing steel expanding plugs have poor environmental corrosion resistance and are prone to red rust on the appearance. In some application scenarios, the corrosion compounds such as red rust generated by the steel expanding plugs will enter the internal channels of the parts, pollute the internal liquid medium of the parts, and seriously block the fine channels inside the parts, causing significant impacts.

[0057]

[0058] ​For the expansion plugs of the above embodiments, both the core rod 1 and the sleeve 2 are made of aluminum alloy, and the surfaces of the core rod 1 and the sleeve 2 are subjected to anodic oxidation treatment, that is, a dense oxide film is formed on the surfaces of the core rod 1 and the sleeve 2 in the air. Therefore, the expansion plug will not produce serious corrosion in actual applications, and can greatly reduce the corrosion of the plug when applied in industries such as the automotive industry, avoiding the pollution and blockage risks of the steel expansion plug in actual use.

Claims

1. A conical core rod expanding plug, characterized in that, It includes a core rod (1) and a sleeve (2). The core rod (1) includes a large circular surface (11), a conical section (12), and a small circular surface (13) arranged in sequence from one end to the other end. The outer diameter of the conical section (12) gradually decreases from one end to the other end. An internal threaded hole (14) is axially provided at the center of the small circular surface (13). The sleeve (2) is sleeved outside the core rod (1). The sleeve (2) is cylindrical. The sleeve (2) includes an outer sleeve wall (21) on the outside and a hollowed-out part (22) on the inside. The outer sleeve wall (21) is in close fit with the inner wall of the mounting hole (3). The large circular surface (11), the conical section (12), and the small circular surface (13) are all in interference fit with the inside of the sleeve (2). A plurality of outer annular sealing grooves (23) are provided on the outer sleeve wall (21) along the circumferential direction. The outer annular sealing grooves (23) are arranged in a toothed pattern. The outer sleeve wall (21) is in close fit with the inner wall of the mounting hole (3) through the outer annular sealing grooves (23). A plurality of inner annular sealing grooves (121) are provided on the conical section (12). The inner annular sealing grooves (121) are arranged in a toothed pattern. The conical section (12) is in close fit with the inner wall of the hollowed-out part (22) through the inner annular sealing grooves (121). The inclination directions of the inner annular sealing grooves (121) and the annular sealing grooves (23) are opposite.

2. The conical core rod expanding plug according to claim 1, characterized in that, An arc chamfer is provided at the outer edge of the small circular surface (13).

3. A conical core rod expanding plug according to claim 1, characterized in that, The large circular surface (11) is convex outward in an arc shape from the outer periphery to the axis.

4. A conical core rod expanding plug according to claim 1, wherein, The core rod (1) further includes a flange (15). The outer diameter of the flange (15) is larger than the outer diameter of the large circular surface (11). The flange (15) is integrally formed with one end of the large circular surface (11).

5. A conical core rod expanding plug, characterized in that, It includes a core rod (1) and a sleeve (2). The core rod (1) includes a large circular surface (11), a conical section (12), and a small circular surface (13) arranged in sequence from one end to the other end. The outer diameter of the conical section (12) gradually decreases from one end to the other end. An internal threaded hole (14) is axially provided at the center of the small circular surface (13). The sleeve (2) is sleeved outside the core rod (1). The sleeve (2) includes an outer sleeve wall (21) on the outside and a hollowed-out part (22) on the inside. The outer sleeve wall (21) is in close fit with the inner wall of the mounting hole (3). The large circular surface (11), the conical section (12), and the small circular surface (13) are all in interference fit with the hollowed-out part (22).

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