Internal expansion clamp

Abstract

The utility model relates to an internal expansion clamp which comprises an expansion sleeve, a fastening screw and an expansion core, the expansion core comprises a frustum, the frustum is in the shape of a cone with the outer diameter gradually shrunk from bottom to top, and a threaded hole is formed in the upper end face of the expansion core; the outer wall of the expansion sleeve is cylindrical, the inner hole of the expansion sleeve is conical, the inner hole of the expansion sleeve is matched with the outer wall of the frustum, and a through hole penetrating up and down is formed in the center of the expansion sleeve; the fastening screw penetrates through the through hole of the expansion sleeve and extends to the expansion core to be connected with the threaded hole. According to the utility model, the machined part is sleeved outside the expansion sleeve, the fastening screw is screwed into the threaded hole, and the expansion sleeve expands outwards to support the machined part. And after machining is completed, the fastening screw is unscrewed, the expansion sleeve shrinks, in this way, the machined part is taken down, and convenience is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical manufacturing; specifically, the utility model relates to an internal expansion clamp. Background Art

[0002] In the mechanical processing industry, thin-walled pipes and sleeves are often encountered. At present, for these thin-walled parts, the thin wall strength is low, and it is not suitable to directly use the outer surface of the part as the positioning and clamping surface, which will damage the thin-walled parts. In the prior art, it is generally necessary to position and clamp in the form of internal support, but after the processing of thin-walled pipes and sleeves is completed, it is difficult to detach from the positioning clamp in the form of internal support. Therefore, the processing of parts such as thin-walled pipes is a difficult point in pipe processing in practice. Utility Model Content

[0003] The purpose of the utility model is to provide an internal expansion clamp, which can solve or at least alleviate one or more of the above-mentioned problems and other problems existing in the prior art.

[0004] In order to achieve the above-mentioned object, the utility model provides an internal expansion clamp, wherein the internal expansion clamp comprises:

[0005] The expansion core is in the shape of a cone with a gradually shrinking outer diameter from bottom to top, and a threaded hole is provided on the upper end surface of the expansion core;

[0006] An expansion sleeve, wherein the outer wall of the expansion sleeve is cylindrical and the inner hole is conical, the inner hole of the expansion sleeve matches the outer wall of the frustum, and a through hole penetrating from top to bottom is provided at the center of the expansion sleeve;

[0007] A fastening screw passes through the through hole of the expansion sleeve and extends to the expansion core to be connected with the threaded hole.

[0008] In the internal expansion fixture as described above, optionally, the expansion sleeve is made of spring steel, and a plurality of uniform expansion grooves are provided on the outer side wall, and the direction of the expansion grooves is parallel to the central axis direction of the expansion sleeve.

[0009] In the internal expansion clamp as described above, optionally, the expansion sleeve is divided into two parts, an upper part and an lower part, an integral structure, the upper part is a basic section, and the lower part is an expansion section. The conical hole inside the expansion sleeve is located in the expansion section, and the expansion groove is provided on the outside of the expansion sleeve. The size of the through hole in the basic section matches the fastening screw.

[0010] In the internal expansion clamp as described above, optionally, the internal expansion clamp also includes a cover plate, which is detachably arranged on the upper end surface of the expansion sleeve, and an adjustment hole for adjusting the fastening screw is arranged at the center position of the cover plate, and the inner diameter of the adjustment hole is smaller than the outer diameter of the head of the fastening screw and larger than the size of the head slot hole of the fastening screw.

[0011] In the aforementioned internal expansion clamp, optionally, the cover plate is detachably connected to the expansion sleeve via a limit screw.

[0012] In the internal expansion fixture as described above, optionally, the upper end surface of the expansion sleeve is provided with a groove, the cover plate is a step structure with a boss that can be embedded in the groove, and the through hole at the center position of the expansion sleeve is a countersunk hole.

[0013] In the aforementioned internal expansion fixture, optionally, the depth of the threaded hole is not less than the height of the frustum.

[0014] In the internal expansion fixture as described above, optionally, the expansion core further comprises a chassis connected to the thicker end of the frustum, and the outer diameter of the chassis is greater than the outer diameter of the expansion sleeve.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] According to the internal expansion clamp of the utility model, the workpiece is sleeved outside the expansion sleeve, and the fastening screw is screwed into the threaded hole, and the expansion sleeve expands outside to support the workpiece. After the processing is completed, the fastening screw is loosened, and the expansion sleeve shrinks, so that the workpiece can be removed conveniently. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the internal expansion clamp of the utility model;

[0018] Figure 2 It is an exploded view of the internal expansion clamp of the utility model;

[0019] Figure 3 It is a cross-sectional view of the internal expansion clamp of the utility model.

[0020] In the figure: 1. expansion core; 2. expansion sleeve; 3. fastening screw; 4. cover plate; 5. cone; 6. chassis; 7. connecting handle; 8. threaded hole; 9. through hole; 10. expansion slot; 11. groove; 12. limit screw; 13. adjustment hole. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] It should be noted that, in the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. The terms "first", "second" and similar words used in the description of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components, and therefore cannot be understood as limitations on the present invention.

[0023] Furthermore, it should be understood that for the sake of ease of description, the sizes of the various components shown in the drawings are not drawn according to actual proportions. For example, the thickness or width of certain layers may be exaggerated relative to other layers.

[0024] It should be noted that like reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined or described in one drawing, it will not require further detailed discussion and description in the description of the subsequent drawings.

[0025] like Figure 1-3 As shown, the internal expansion fixture includes: an expansion core 1, an expansion sleeve 2, and a fastening screw 3. The expansion core 1 includes a frustum 5, a chassis 6, and a connecting handle 7 connected in sequence from top to bottom. The frustum 5 is in the shape of a cone with an outer diameter that gradually shrinks from bottom to top. A threaded hole 8 is provided on the upper end surface of the expansion core 1. Among them, the connecting handle 7 is used to be installed on processing equipment such as machine tools. The outer wall of the expansion sleeve 2 is cylindrical and the inner hole is conical. The inner hole of the expansion sleeve 2 matches the outer wall of the frustum 5. A through hole 9 that penetrates from top to bottom is provided at the center of the expansion sleeve 2. The fastening screw 3 passes through the through hole 9 of the expansion sleeve 2 and extends to the expansion core 1 and connects with the threaded hole 8. In this way, the fastening screw 3 is rotated to push the expansion sleeve 2 to expand outward. As the expansion sleeve 2 presses against the expansion core 1, the outer diameter of the expansion sleeve 2 will also increase accordingly, achieving the effect of outward expansion, and then the workpiece sleeved on the expansion sleeve 2 can be supported.

[0026] Furthermore, the expansion sleeve 2 is made of spring steel, and a plurality of uniform expansion grooves 10 are provided on the outer side wall, and the direction of the expansion grooves 10 is parallel to the central axis direction of the expansion sleeve 2 .

[0027] Furthermore, the expansion sleeve 2 is divided into two parts, an upper part and an lower part, an integrated structure, the upper part is a basic section, and the lower part is an expansion section. The conical hole inside the expansion sleeve 2 is located in the expansion section, and an expansion groove 10 is provided outside the expansion sleeve 2. The size of the through hole in the basic section matches the fastening screw 3.

[0028] When in use, the workpiece is sleeved outside the expansion sleeve 2, and the fastening screw 3 is screwed into the threaded hole 8, and the expansion sleeve 2 expands and supports the workpiece. After the processing is completed, the fastening screw 3 is loosened, the expansion sleeve 2 shrinks, and the workpiece is removed.

[0029] Furthermore, the internal expansion fixture also includes a cover plate 4, which is detachably arranged on the upper end surface of the expansion sleeve 2, and an adjustment hole 13 for adjusting the screw 3 is arranged at the center of the cover plate 4. The inner diameter of the adjustment hole 13 is smaller than the outer diameter of the head of the fastening screw 3, and larger than the size of the head slot of the fastening screw 3 (such as a slotted hole, a cross hole, etc.), so that it is convenient for tools to be inserted into the adjustment hole 13 to tighten or loosen the fastening screw 3 and limit the position of the fastening screw 3. In this way, when the expansion sleeve 2 achieves the effect of external expansion, the cover plate 4 can limit the reversal of the fastening screw 3, and always keep the expansion sleeve 2 supporting the workpiece.

[0030] Furthermore, the cover plate 4 is detachably connected to the expansion sleeve 2 via a limit screw 12 .

[0031] When the expansion sleeve 2 needs to be shrunk, the fastening screw 3 is reversed through the adjustment hole 13 by a tool, and the fastening screw 3 is screwed out from the threaded hole 8, the cone 5 and the expansion sleeve 2 are shrunk, and at the same time, since the cover plate 4 is fastened to the upper surface of the expansion sleeve 2 by the limit screw 12, the cover plate 4 and the expansion sleeve 2 are separated from the cone 5 of the expansion core 1 as a whole. At this time, the outer diameter of the expansion sleeve 2 is restored to the state without external expansion, and the supporting effect of the expansion sleeve 2 on the workpiece disappears, which facilitates the removal of the workpiece.

[0032] Furthermore, the depth of the threaded hole 8 is not less than the height of the frustum 5 .

[0033] Furthermore, the outer diameter of the bottom plate 6 is larger than the outer diameter of the expansion sleeve 2 , and the bottom plate 6 can resist the expansion sleeve 2 .

[0034] Furthermore, a groove 11 is provided on the upper end surface of the expansion sleeve 2, the cover plate 4 is a step structure with a boss that can be embedded in the groove 11, and the through hole 9 at the center of the expansion sleeve 2 is a countersunk hole.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An internal expansion fixture, characterized in that: The internal expansion fixture comprises: An expanding core (1), the expanding core (1) comprising a frustum (5), the frustum (5) being in the shape of a cone with an outer diameter gradually shrinking from bottom to top, and a threaded hole (8) being provided on the upper end surface of the expanding core (1); An expansion sleeve (2), wherein the outer wall of the expansion sleeve (2) is cylindrical and the inner hole is conical, the inner hole of the expansion sleeve (2) matches the outer wall of the frustum (5), and a through hole (9) penetrating from top to bottom is provided at the center position of the expansion sleeve (2); A fastening screw (3), wherein the fastening screw (3) passes through the through hole (9) of the expansion sleeve (2) and extends to the expansion core (1) to be connected with the threaded hole (8); The internal expansion clamp also includes a cover plate (4), which is detachably arranged on the upper end surface of the expansion sleeve (2), and an adjustment hole (13) for adjusting the fastening screw (3) is arranged at the center position of the cover plate (4), and the inner diameter of the adjustment hole (13) is smaller than the outer diameter of the head of the fastening screw (3) and larger than the size of the head slot of the fastening screw (3).

2. The internal expansion fixture according to claim 1, characterized in that: The expansion sleeve (2) is made of spring steel, and a plurality of uniform expansion grooves (10) are provided on the outer wall. The direction of the expansion grooves (10) is parallel to the central axis direction of the expansion sleeve (2).

3. The internal expansion fixture according to claim 2, characterized in that: The expansion sleeve (2) is divided into two parts, an upper part and an lower part, with an integrated structure. The upper part is a basic section and the lower part is an expansion section. The conical hole inside the expansion sleeve (2) is located in the expansion section. The expansion groove (10) is arranged outside the expansion sleeve (2). The size of the through hole (9) in the basic section matches the fastening screw (3).

4. The internal expansion fixture according to claim 1, characterized in that: The cover plate (4) is detachably connected to the expansion sleeve (2) via a limiting screw (12).

5. The internal expansion fixture according to claim 1, characterized in that: The upper end surface of the expansion sleeve (2) is provided with a groove (11), the cover plate (4) is a step structure with a boss capable of being embedded in the groove (11), and the through hole (9) at the center position of the expansion sleeve (2) is a countersunk hole.

6. The internal expansion fixture according to claim 1, characterized in that: The depth of the threaded hole (8) is not less than the height of the frustum (5).

7. The internal expansion fixture according to claim 1, characterized in that: The expansion core (1) further comprises a chassis (6) connected to the thicker end of the cone (5); the outer diameter of the chassis (6) is greater than the outer diameter of the expansion sleeve (2).

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