Hydraulic bolt tensioner

Abstract

The utility model discloses a hydraulic bolt stretcher which comprises an oil cylinder barrel, a piston column and a stretching head. A lower cylinder opening of the oil cylinder barrel extends inwards to form a supporting ridge, and the lower side of the supporting ridge is connected with a supporting ring base. The piston column is inserted in the oil cylinder barrel, a limiting ring groove is formed in the outer ring face of the piston column, and the supporting ridge is embedded in the limiting ring groove. An oil cavity is formed between the bearing ridge and the upper groove wall of the limiting ring groove, an oil injection hole channel communicated with the oil cavity is formed in the bearing ridge, and the oil injection hole channel penetrates through the cylinder wall of the oil cylinder barrel. The upper end face of the piston column extends outwards to form a protective flange, the protective flange is turned downwards and extends to form a ring sleeve, and a sealing ring is arranged between the outer barrel wall of the oil cylinder barrel and the ring sleeve. The stretching head is placed on the upper end face of the piston column, a lining pipe is detachably installed in an assembling through hole of the stretching head, internal threads are formed in the lining pipe, and the lining pipe is screwed to a bolt to be stretched. The hydraulic bolt tensioner solves the problem that the service life of the hydraulic bolt tensioner is shortened when the hydraulic bolt tensioner is used in a field environment.

Description

Technical Field

[0001] This utility model relates to the technical field of bolt tensioning devices, specifically to a hydraulic bolt tensioner. Background Technology

[0002] A hydraulic bolt tensioner, or bolt tensioner for short, uses a hydraulic booster pump to provide a hydraulic power source. The tension force is determined based on the tensile strength, yield coefficient, and elongation of the material. The tension force generated by the ultra-high pressure oil pump causes the bolt to be stretched within its elastic deformation zone, resulting in slight deformation of the bolt diameter. This makes the nut easier to loosen. In addition, it can also be used as a device to apply axial force to a hydraulic interference fit for top pressure installation.

[0003] When existing hydraulic bolt tensioners are used in outdoor environments, rainwater and dust can easily enter the gap between the piston and the inner wall of the hydraulic cylinder, causing damage to the piston and hydraulic cylinder and affecting the service life of the hydraulic bolt tensioner.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] To overcome the shortcomings of existing technologies, a hydraulic bolt tensioner is provided to solve the problem of reduced service life of hydraulic bolt tensioners when used in outdoor environments.

[0006] To achieve the above objectives, a hydraulic bolt tensioner is provided, comprising:

[0007] The cylinder barrel has a lower opening that extends inward to form a support sill. The support sill is arranged in a circle along the circumference of the cylinder barrel. The lower side of the support sill is connected to an external support ring seat for detachably fitting a nut.

[0008] A piston rod is vertically inserted into the cylinder barrel. A limiting annular groove is formed on the outer annular surface of the piston rod, penetrating the lower end face of the piston rod. A support sill is embedded in the limiting annular groove. An oil cavity is formed between the support sill and the upper wall of the limiting annular groove. An oil injection channel is formed in the support sill, communicating with the oil cavity. The oil injection channel penetrates the cylinder wall. The upper end face of the piston rod extends outward to form a protective flange. The protective flange extends downward to form a ring sleeve. The ring sleeve is movably fitted onto the outside of the upper end of the cylinder barrel. A receiving annular groove is opened on the outer side of the cylinder wall. A sealing ring for sealing the gap between the cylinder barrel and the ring sleeve is embedded in the receiving annular groove.

[0009] A tensioning head rests on the upper end face of the piston rod. A vertically arranged assembly through hole is formed in the middle of the tensioning head. An inner liner tube is detachably installed in the assembly through hole. The inner liner tube has an internal thread and is screwed into the bolt to be tensioned.

[0010] Furthermore, an assembly ring groove is provided on the outer side of the cylinder wall of the cylinder, the assembly ring groove is located below the receiving ring groove, a support ring plate is slidably provided in the assembly ring groove, the support ring plate is detachably connected to the ring sleeve, and a return spring is connected between the support ring plate and the top groove wall of the assembly ring groove.

[0011] Furthermore, the bottom wall of the assembly ring groove is inclined downwards.

[0012] Furthermore, a support flange is formed on the upper part of the stretching head, and the support flange is arranged in a circle along the circumferential direction of the stretching head, with the upper end face of the piston rod supported on the support flange.

[0013] Furthermore, the side of the support flange is provided with a plurality of torsion holes, which are spaced apart along the circumferential direction of the support flange.

[0014] Furthermore, the upper end face of the stretching head is provided with a receiving groove, the upper end of the inner liner tube is formed with a limiting flange, the limiting flange is embedded in the receiving groove, the side of the limiting flange is provided with a locking hole, and a locking rod is detachably installed in the torsion hole and the locking hole.

[0015] Furthermore, the wall of the assembly through hole is provided with a vertically arranged limiting groove, the limiting groove is connected to the receiving groove, a limiting protrusion is connected between the inner liner tube and the limiting flange, the limiting protrusion is slidably disposed in the limiting groove, and the bottom groove wall of the limiting groove is supported by the limiting protrusion.

[0016] The beneficial effects of this utility model are as follows: In the hydraulic bolt tensioner of this utility model, the upper end of the piston rod extends outward to form a protective flange, and the protective flange is turned down to form a ring sleeve fitted onto the outer wall of the cylinder. A sealing ring is provided between the cylinder and the ring sleeve. When the piston rod extends out of the cylinder, the protective flange and the ring sleeve cover the gap between the cylinder and the piston rod. At the same time, the sealing ring plays a sealing role, thereby preventing rainwater and dust from entering the cylinder and improving the service life of the piston rod and the cylinder.

[0017] This utility model discloses a hydraulic bolt tensioner with a detachable inner liner installed inside the tensioning head. When the internal threads of the inner liner wear due to long-term use of the hydraulic bolt tensioner, only the inner liner needs to be removed and replaced, resulting in low maintenance costs for the tensioning head. Attached Figure Description

[0018] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0019] Figure 1 This is a schematic diagram of the structure of the hydraulic bolt tensioner according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the inner lining tube according to an embodiment of the present utility model.

[0021] Figure 3 This is a schematic diagram of the structure of the stretching head according to an embodiment of the present invention. Detailed Implementation

[0022] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the scope of the utility model. Furthermore, it should be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Reference Figures 1 to 3 As shown, this utility model provides a hydraulic bolt tensioner, including: a cylinder 1, a piston rod 3, and a tensioning head 4.

[0025] The cylinder barrel 1 is cylindrical and has an upper opening and a lower opening. The lower opening of the cylinder barrel 1 extends inward to form a support sill 11, which is arranged in a circle along the circumference of the cylinder barrel 1.

[0026] A support ring seat 2 is connected to the lower side of the support sill 11. When the tension bolt is stretched, the support ring seat 2 is detachably sleeved on the outside of the nut.

[0027] The piston rod 3 is vertically and retractably inserted into the cylinder 1. A limiting ring groove is formed on the lower part of the outer annular surface of the piston rod 3, and the limiting ring groove penetrates the lower end face of the piston rod 3. The support plate 11 of the cylinder 1 is embedded in the limiting ring groove of the piston rod 3, and the support plate 11 is supported by the piston rod 3.

[0028] In this embodiment, an oil cavity is formed between the upper groove wall of the limiting ring groove of the support sill 11 and the piston rod 3. An oil injection channel a is formed in the support sill 11 that communicates with the oil cavity. The oil injection channel a penetrates the cylinder wall of the cylinder 1.

[0029] The upper end of the piston rod 3 extends outward to form a protective flange, and the protective flange extends downward to form a ring 31, which is movably sleeved on the outside of the upper end of the cylinder barrel 1.

[0030] The outer side of the cylinder wall of the cylinder 1 is provided with a receiving annular groove, and a sealing ring 12 is embedded in the receiving annular groove, thereby sealing the gap between the cylinder 1 and the ring sleeve 31.

[0031] The tensioning head 4 rests on the upper end face of the piston column 3. In this embodiment, a mounting through hole b is formed in the middle of the tensioning head 4, and the mounting through hole b is arranged vertically. An inner liner tube 5 is detachably installed in the mounting through hole b of the tensioning head 4. The inner liner tube 5 has internal threads and is screwed into the bolt to be tensioned.

[0032] Specifically, in combination Figure 1 , Figure 3 As shown, in this embodiment, a support flange 41 is formed on the upper part of the stretching head 4. The support flange 41 is arranged in a circle along the circumferential direction of the stretching head 4, and the upper end face of the piston column 3 is supported on the support flange 41 of the stretching head 4.

[0033] Multiple torsion holes c are provided on the side of the support flange 41, and the multiple torsion holes c are spaced apart along the circumference of the support flange 41. When using a hydraulic bolt tensioner, the tension head (inner liner 5) is screwed into the bolt to be tensioned, and the tension head 4 is tightened by inserting the lever into the torsion hole c.

[0034] Combination Figure 2 , Figure 3 As shown, in this embodiment, the upper end face of the stretching head 4 is provided with a receiving groove d, which is connected to the assembly through hole b. The upper end of the inner liner tube 5 forms a limiting flange 51, which is arranged in a circle along the circumference of the inner liner tube 5. The limiting flange 51 of the inner liner tube 5 is embedded in the receiving groove d of the stretching head 4.

[0035] A locking hole e is provided on the side of the limiting flange 51. In this embodiment, two locking holes e are provided on the side of the limiting flange 51, and the two locking holes e are respectively located on opposite sides of the limiting flange 51. The two locking holes e are respectively aligned with the two torsion holes c of the stretching head. A locking rod 42 is detachably installed in the torsion hole c and the locking hole e. In this embodiment, the wall of the locking hole e is formed with internal threads, and the outside of the locking rod 42 is formed with external threads. The locking rod 42 passes through the torsion hole c and is screwed into the locking hole e, thereby locking the inner liner tube 5.

[0036] In a preferred embodiment, a limiting groove f is formed in the wall of the assembly through hole b of the stretching head. The limiting groove f is vertically arranged and communicates with the receiving groove d. A limiting rib 52 is connected between the outer wall of the inner liner tube 5 and the limiting flange 51, and the limiting rib 52 is vertically arranged. The limiting rib 52 of the inner liner tube slides in the limiting groove f of the stretching head, and the bottom wall of the limiting groove f is supported by the limiting rib 52.

[0037] When installing the inner liner tube, first align the inner liner tube 5 with the assembly through hole b of the stretching head 4, and align the limiting protrusion 52 with the limiting groove f of the stretching head 4. Then, insert the inner liner tube 5 into the assembly through hole b, ensuring that the limiting protrusions 52 are inserted into the limiting grooves f one-to-one, and the limiting flange 51 of the inner liner tube 5 is embedded in the receiving groove d of the stretching head 4. Finally, by inserting the locking rod 42 into the torsion hole c of the stretching head 4 and screwing it into the locking hole e of the inner liner tube 5, the inner liner tube 5 is locked to the stretching head 4, completing the installation of the inner liner tube.

[0038] Locking rod 42 locks the inner liner tube 5 to prevent it from loosening. When the tensioning head 4 tensions the bolt, the bottom of the receiving groove d is supported by the limiting flange 51 of the inner liner tube, and the bottom wall of the limiting groove f is supported by the limiting protrusion 52 of the inner liner tube, thereby increasing the supporting force of the tensioning head 4 on the inner liner tube 5 and ensuring the stability of the tensioning head in use.

[0039] In a preferred embodiment, an assembly ring groove g is provided on the outer side of the cylinder wall 1, and the assembly ring groove g is located below the receiving ring groove (sealing ring 12). A support ring plate 6 is slidably disposed in the assembly ring groove g, and the support ring plate 6 is detachably connected to the ring sleeve 31. A return spring 7 is connected between the support ring plate 6 and the top groove wall of the assembly ring groove g.

[0040] As a preferred embodiment, the bottom wall of the assembly ring groove g is inclined downward, which facilitates rainwater and dust to slide down along the bottom wall of the assembly ring groove g, reducing the accumulation of rainwater and dust.

[0041] In this utility model of hydraulic bolt tensioner, the outer ring surface of the piston column 3 and the inner ring surface of the support sill 11 are respectively provided with sealing rings 8, so that the oil chamber forms a sealed cavity.

[0042] The hydraulic bolt tensioner of this invention has a notch formed on the side of the support ring seat 2. After the hydraulic bolt tensioner tensions the bolt, the nut can be tightened or loosened by rotating it through the notch.

[0043] When using the hydraulic bolt tensioner of this utility model, first, the adjusting nut sleeve 9 is placed on the nut, and the support ring seat 2 of the hydraulic bolt tensioner is placed on the outside of the adjusting nut sleeve 9. Then, the tensioning head 4 is rotated so that the inner liner tube 5 is screwed onto the bolt to be tensioned, and the tensioning head is tightened by inserting the lever into the turning hole c.

[0044] After high-pressure oil is introduced into the oil injection channel a, the high-pressure oil fills the oil chamber. As the oil volume in the oil chamber increases, it lifts the piston column 3, which in turn lifts the tension head 4. The tension head 4 (within the inner liner tube 5) then tensions the bolt. After the bolt is tensioned, the adjusting nut sleeve 9 is rotated using a lever to tighten or loosen the nut.

[0045] After the hydraulic bolt tensioner is used, the high-pressure oil returns, and the piston rod 3 is reset under the action of the return spring 7.

[0046] When the hydraulic bolt tensioner of this utility model is used outdoors, after the piston rod 3 extends out of the cylinder barrel 1, the protective flange and the ring sleeve 31 cover the upper end face of the cylinder barrel 1, and the sealing ring 12 seals the gap between the cylinder barrel 1 and the ring sleeve 31, thereby preventing rainwater and dust from entering between the piston rod 3 and the cylinder barrel 1, and increasing the service life of the piston rod 3 and the cylinder barrel 1.

[0047] When the internal thread of the inner liner tube 5 is worn, the hydraulic bolt tensioner of this utility model can quickly replace the inner liner tube 5 by disassembling and assembling the locking rod 42, avoiding the need to replace the entire tensioning head and reducing the maintenance and replacement cost of the tensioning head.

[0048] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A hydraulic bolt tensioner, characterized in that, include: The cylinder barrel has a lower opening that extends inward to form a support sill. The support sill is arranged in a circle along the circumference of the cylinder barrel. The lower side of the support sill is connected to an external support ring seat for detachably fitting a nut. A piston rod is vertically inserted into the cylinder barrel. A limiting annular groove is formed on the outer annular surface of the piston rod, penetrating the lower end face of the piston rod. A support sill is embedded in the limiting annular groove. An oil cavity is formed between the support sill and the upper wall of the limiting annular groove. An oil injection channel is formed in the support sill, communicating with the oil cavity. The oil injection channel penetrates the cylinder wall. The upper end face of the piston rod extends outward to form a protective flange. The protective flange extends downward to form a ring sleeve. The ring sleeve is movably fitted onto the outside of the upper end of the cylinder barrel. A receiving annular groove is opened on the outer side of the cylinder wall. A sealing ring for sealing the gap between the cylinder barrel and the ring sleeve is embedded in the receiving annular groove. A tensioning head rests on the upper end face of the piston rod. A vertically arranged assembly through hole is formed in the middle of the tensioning head. An inner liner tube is detachably installed in the assembly through hole. The inner liner tube has an internal thread and is screwed into the bolt to be tensioned.

2. The hydraulic bolt tensioner of claim 1, wherein, An assembly ring groove is provided on the outer side of the cylinder wall of the cylinder. The assembly ring groove is located below the receiving ring groove. A support ring plate is slidably provided in the assembly ring groove. The support ring plate is detachably connected to the ring sleeve. A return spring is connected between the support ring plate and the top groove wall of the assembly ring groove.

3. The hydraulic bolt tensioner of claim 2, wherein, The bottom wall of the assembly ring groove is inclined downwards.

4. The hydraulic bolt tensioner of claim 1, wherein, The upper part of the stretching head has a support flange, which is arranged in a circle along the circumferential direction of the stretching head, and the upper end face of the piston rod is supported by the support flange.

5. The hydraulic bolt tensioner of claim 4, wherein, The side of the support flange is provided with a plurality of torsion holes, which are spaced apart along the circumferential direction of the support flange.

6. The hydraulic bolt tensioner of claim 5, wherein, The upper end face of the stretching head is provided with a receiving groove, the upper end of the inner liner tube is formed with a limiting flange, the limiting flange is embedded in the receiving groove, the side of the limiting flange is provided with a locking hole, and a locking rod is detachably installed in the torsion hole and the locking hole.

7. The hydraulic bolt tensioner of claim 6, wherein, The assembly through hole has a vertically arranged limiting groove in its wall, which is connected to the receiving groove. A limiting protrusion is connected between the inner liner and the limiting flange. The limiting protrusion slides in the limiting groove, and the bottom wall of the limiting groove is supported by the limiting protrusion.

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