Compact bolt tensioner

Abstract

The utility model relates to a compact bolt tensioner which comprises a tensioning body, the tensioning body comprises a bridge frame, a shifting ring, a tensioning nut and a piston ring, the bridge frame is of a hollow cylindrical structure, the shifting ring is arranged in the bridge frame, the tensioning nut is arranged above the bridge frame, a piston mounting groove is formed in the bottom of the tensioning nut, and the piston ring is arranged in the piston mounting groove. The piston ring is installed in the piston installation groove, and a closed cavity is formed in the piston installation groove. According to the bolt tensioner, the stretching nut and the piston ring are matched to form a structure similar to a hydraulic oil cylinder in function, so that the oil cylinder is removed from the bolt tensioner, the weight and the size of the bolt tensioner are reduced, the bolt tensioner can work in a narrow space, and the service life of the bolt tensioner is prolonged. The device has the advantages of light size, light weight, small motion inertia and high reaction speed.

Description

Technical Field

[0001] The utility model relates to the technical field of spiral tensioners, in particular to a compact bolt tensioner. Background Art

[0002] Bolt tensioners are tools used to tighten or remove large-diameter bolts that are subjected to large forces. After being used for a period of time on some large equipment, the bolts will become loose, posing a great safety hazard. The bolts need to be tightened, but it is difficult to tighten them into place by manual operation alone, so a bolt tensioner is needed to assist. Therefore, in the fields of petrochemicals, heavy machinery, etc., bolt tensioners are often needed to pre-tighten and remove high-strength bolts of various large equipment. When using a bolt tensioner, it is usually necessary to tighten multiple bolts, so the position of the bolt tensioner needs to be moved multiple times. Ordinary bolt tensioners are relatively large in size and weight, making them extremely inconvenient to use. In addition, ordinary bolt tensioners are difficult to work on bolts in some small spaces. Therefore, there is an urgent need for a small and lightweight bolt tensioner that can be used to tighten or remove bolts when space is limited. Utility Model Content

[0003] Based on this, it is necessary to provide a compact bolt tensioner to solve the current problems of difficulty in pre-tightening or disassembling bolts in confined spaces when space is limited, and the heavy weight of existing ordinary bolt tensioners that are difficult to carry. It has the advantages of small size, light weight, small motion inertia, and fast response speed.

[0004] The technical solution of the utility model for solving the above-mentioned technical problems is as follows: a compact bolt tensioner, comprising a tensioning body, wherein the tensioning body comprises a bridge, a shifting ring, a tensioning nut and a piston ring, the bridge being a hollow cylindrical structure, the shifting ring being arranged inside the bridge, the tensioning nut being arranged above the bridge, a piston mounting groove being provided at the bottom of the tensioning nut, the piston ring being installed in the piston mounting groove, and forming a closed cavity inside the piston mounting groove.

[0005] In one embodiment, the bridge is provided with a rotation groove for rotating the dial ring; the rotation groove is provided on the side wall of the bridge and is connected to the inner and outer surfaces of the side wall of the bridge.

[0006] In one embodiment, there are two rotation slots, which are arranged opposite to each other.

[0007] In one embodiment, the shifting ring is a circular ring with a through hole inside, and the shape of the through hole matches the shape of the target nut; a plurality of shifting holes distributed at equal intervals are provided on the side wall of the shifting ring.

[0008] In one embodiment, the diameter of the shifting hole is the same as the height of the rotation slot; the rotation slot on the bridge and the shifting hole on the shifting ring are on the same horizontal plane.

[0009] In one embodiment, the width of the piston mounting groove is the same as the width of the side wall of the piston ring, and the depth of the piston mounting groove is greater than the height of the piston ring.

[0010] In one embodiment, a connecting portion is provided at the bottom of the piston ring, and the connecting portion of the piston groove is engaged with a protruding portion provided on the upper end surface of the bridge.

[0011] In one embodiment, a first sealing groove is provided on the inner side wall of the piston mounting groove, and a second sealing groove is provided on the outer side wall of the piston ring. Sealing rings are provided in both the first sealing groove and the second sealing groove.

[0012] In one embodiment, the stretching nut is provided with an internal thread, and the upper end of the outer wall of the stretching nut is provided with a chamfer, and the chamfer is provided with a connecting hole communicating with the closed cavity.

[0013] In one embodiment, it also includes a hydraulic pump and an oil pipe; one end of the oil pipe is sealed with the connecting hole, and the other end is sealed with the hydraulic pump; the hydraulic pump is also provided with a pressure gauge for measuring the output pressure of the hydraulic pump.

[0014] The beneficial effects of the present invention are as follows: the present invention provides a compact bolt tensioner, which forms a hydraulic cylinder with the tensioning nut and the piston ring by arranging the piston ring in the tensioning nut, thereby eliminating the cylinder that occupies a large space in ordinary compact bolt tensioners, thereby reducing the overall volume and weight of the bolt tensioner, so that the bolt tensioner can be used in places with a small space; and because the bolt tensioner is light in weight, it is convenient for the operator to carry the bolt tensioner to different locations for use, which requires less physical strength from the operator and reduces the difficulty of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 Schematic diagram of the structure of a compact bolt tensioner according to one embodiment;

[0017] Figure 2 Schematic diagram of the cross-sectional structure of a compact bolt tensioner according to one embodiment;

[0018] Figure 3 The figure is a schematic structural diagram of a shift ring of a compact bolt tensioner according to one embodiment.

[0019] In the accompanying drawings, 1, bridge; 11, rotating groove; 2, shifting ring; 21, shifting hole; 3, stretching nut; 31, piston mounting groove; 32, connecting hole; 33, first sealing groove; 4, piston ring; 41, second sealing groove. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The following will further describe the technical solution of the present invention in conjunction with the drawings of the embodiments of the present invention, and the present invention is not limited to the following specific implementation methods.

[0021] It should be understood that the same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", etc. indicating an orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0022] In one embodiment, Figures 1 to 3 As shown, a compact bolt tensioner includes a tensioning body, which includes a bridge 1 for supporting the tensioning body, a shifting ring 2 for rotating the nut on the bolt, a tensioning nut 3 for connecting the bolt and the tensioning body, and a piston ring 4 that works with the tensioning nut 3 to form a hydraulic cylinder. The shifting ring 2 is arranged inside the bridge 1, the tensioning nut 3 is provided with a piston mounting groove 31 at the bottom, and the piston ring 4 is provided with a connecting portion at the bottom. The piston ring 4 is engaged with a raised portion provided on the upper end surface of the bridge 1 through the bottom connecting portion. The tensioning nut 3 and piston ring 4 are assembled and arranged above the bridge 1.

[0023] In one embodiment, the bridge 1 is a hollow cylindrical structure, and two rotation grooves 11 are provided on the side wall of the bridge 1. The rotation grooves 11 connect the inner and outer surfaces of the side wall of the bridge 1. The two rotation grooves 11 are arranged opposite to each other. The rotation groove 11 is used to insert the shift rod into the inner hole of the rotation groove 11 to control the rotation of the shift ring 2, and then tighten or remove the nut on the bolt.

[0024] Furthermore, in order to better control the rotation of the nut on the bolt, the structure of the dial ring 2 is designed; Figure 3 As shown, the shift ring 2 is a circular ring with a through hole, the shape of which matches the shape of the target nut, and the shift ring is sleeved on the target nut when in use; the outer ring diameter of the shift ring 2 is smaller than the inner ring diameter of the bridge 1, so that the shift ring 2 can be set inside the bridge 1; the side wall of the shift ring 2 is also provided with a plurality of shift holes 21 arranged at equal intervals, and the diameter of the shift hole 21 is the same as the height of the rotation slot 11; in this embodiment, the cross-section of the through hole is hexagonal, and the angle of the hexagon is set to be an arc shape; the number of the shift holes 21 is six, and they are distributed in a cross-shaped pattern on the side wall of the shift ring 2; in addition, the rotation slot 11 provided on the bridge 1 and the shift hole 21 on the shift ring 2 are on the same horizontal plane, that is, the lower side line of the rotation slot 11 is tangent to the lower end of the shift hole 21, and the upper side line of the rotation slot 11 is tangent to the upper end of the shift hole 21, which makes it convenient for the shift rod to pass through the rotation slot 11 and be inserted into the shift hole 21 to control the rotation of the shift ring 2.

[0025] In order to reduce the volume of the bolt tensioner, the structure of the tensioning nut 3 is designed, such as Figure 2 As shown, the stretching nut 3 is provided with a piston mounting groove 31 which is recessed upward from the lower surface of the stretching nut 3. The shape of the piston mounting groove 31 is the same as the structure of the piston ring 4. The width of the piston mounting groove 31 is the same as the width of the side wall of the piston ring 4, that is, the inner ring diameter of the piston mounting groove 31 is equal to the inner ring diameter of the piston ring 4, the outer ring diameter of the piston mounting groove 31 is equal to the outer ring diameter of the piston ring 4, and the depth of the piston mounting groove 31 is greater than the height of the piston groove, so that the piston ring 4 can be sealed in the piston mounting groove 31 and leave a closed cavity above the piston ring 4;

[0026] In order to further improve the airtightness between the piston mounting groove 31 and the piston ring 4, a first sealing groove 33 is provided on the side wall of the piston mounting groove 31, and a second sealing groove is provided on the outer wall of the piston ring 4, and sealing rings are provided in the first sealing groove 33 and the second sealing groove. In this embodiment, the sealing ring is an O-ring, which is made of NBR (Nitrile Butadiene Rubber) + PTFE (polytetrafluoroethylene) composite material and has good pressure stability and anti-extrusion reliability.

[0027] Furthermore, the stretching nut 3 is provided with an internal thread matching the thread on the bolt, which is used to fix the stretching nut 3 and the bolt; a chamfer is provided at the upper end of the outer wall of the stretching nut 3, and a connecting hole 32 is provided at the chamfer, and the connecting hole 32 is inclined downward, and the closed cavity inside the stretching nut 3 is connected.

[0028] Furthermore, the present invention is further provided with a hydraulic pump and an oil pipe. One end of the oil pipe is sealedly connected to the connection hole 32 on the tension nut 3, and the other end is sealedly connected to the hydraulic pump. The hydraulic pump is also provided with a pressure gauge for detecting the output pressure of the hydraulic pump. In this embodiment, the hydraulic pump is a common hydraulic pump on the market and will not be elaborated here.

[0029] The general working process of the present invention is as follows: the shifting ring is sleeved on the nut connected to the bolt, and then the bridge is sleeved on the shifting ring, and the lower surface of the bridge is in contact with the flange; the stretching nut is threadedly connected to the bolt, and rotated until the lower surfaces of the stretching nut and the piston ring are in contact with the upper surface of the bridge, and then the two ends of the oil pipe are fixedly linked to the connecting hole on the stretching nut and the output port of the hydraulic pump respectively, and the hydraulic pump is used to increase the pressure inside the stretching nut to stretch the bolt upward, and then the shifting rod is inserted into the shifting hole on the shifting ring through the rotating groove on the bridge, and the shifting ring is rotated to drive the nut to rotate, thereby tightening the nut or removing it from the bolt; finally, the stretching body is removed from the bolt after the pressure is released.

[0030] Compared with the prior art, the present invention has at least the following advantages: the bolt tensioner is small in size, and a closed cavity is formed in the piston mounting hole through the interaction between the tensioning nut and the piston ring. The closed cavity is connected to the hydraulic pump, and the tensioning nut and the piston ring combination plays the same role as the hydraulic cylinder, thereby eliminating the cylinder, reducing the size of the bolt tensioner, and making it convenient to tighten or remove bolts in locations with limited space; the bolt tensioner is light in weight, which makes it convenient for operators to carry the bolt tensioner to operate bolts at different positions, reducing the physical requirements for operators to use the bolt tensioner, and reducing the difficulty of operating the bolt tensioner. It has the advantages of light size, light weight, small motion inertia, and fast response speed.

[0031] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art will be able to make other variations or modifications based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A compact bolt tensioner, comprising a tensioning body, characterized in that: The stretching body includes a bridge frame, a shifting ring, a stretching nut and a piston ring. The bridge frame is a hollow cylindrical structure. The shifting ring is arranged inside the bridge frame. The stretching nut is arranged above the bridge frame. A piston mounting groove is provided at the bottom of the stretching nut. The piston ring is installed in the piston mounting groove and forms a closed cavity inside the piston mounting groove.

2. The compact bolt tensioner according to claim 1, characterized in that The bridge is provided with a rotation groove for rotating the dial ring; the rotation groove is arranged on the side wall of the bridge and is connected to the inner and outer surfaces of the side wall of the bridge.

3. The compact bolt tensioner according to claim 2, characterized in that There are two rotating grooves, which are arranged opposite to each other.

4. The compact bolt tensioner according to claim 3, characterized in that The shifting ring is a circular ring with a through hole inside, and the shape of the through hole matches the shape of the target nut; a plurality of shifting holes distributed at equal intervals are provided on the side wall of the shifting ring.

5. The compact bolt tensioner according to claim 4, characterized in that: The diameter of the shifting hole is the same as the height of the rotating groove; the rotating groove on the bridge and the shifting hole on the shifting ring are on the same horizontal plane.

6. The compact bolt tensioner according to claim 1, characterized in that The width of the piston mounting groove is the same as the width of the side wall of the piston ring, and the depth of the piston mounting groove is greater than the height of the piston ring.

7. The compact bolt tensioner according to claim 6, characterized in that A connecting portion is provided at the bottom of the piston ring, and the connecting portion of the piston ring is engaged and connected with a raised portion arranged on the upper end surface of the bridge.

8. The compact bolt tensioner according to claim 7, characterized in that A first sealing groove is provided on the inner side wall of the piston installation groove, and a second sealing groove is provided on the outer side wall of the piston ring. Sealing rings are provided in both the first sealing groove and the second sealing groove.

9. The compact bolt tensioner according to claim 1, characterized in that The stretching nut is provided with an internal thread, and the upper end of the outer wall of the stretching nut is provided with a chamfer, and the chamfer is provided with a connecting hole communicating with the closed cavity.

10. The compact bolt tensioner according to any one of claims 1 to 9, characterized in that: It also includes a hydraulic pump and an oil pipe; one end of the oil pipe is sealed with the connecting hole, and the other end is sealed with the hydraulic pump; the hydraulic pump is also provided with a pressure gauge for measuring the output pressure of the hydraulic pump.

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