Self-locking anti-loosening hydraulic nut

Abstract

The utility model discloses a self-locking anti-loose hydraulic nut which comprises a hydraulic cylinder, a piston and a locking nut, an oil cavity of the hydraulic cylinder is connected with an external pump station through a flow channel, the piston is located in the oil cavity of the hydraulic cylinder and connected with the hydraulic cylinder in a sliding mode, the piston is of an annular structure and provided with an internal thread and an external thread, and the piston is connected with a bolt through the internal thread. The piston is connected with the locking nut through external threads, a notch is formed in the upper position of the piston and is in an arch shape, the perpendicular bisector of the notch penetrates through the middle point of the cross section of the position, where the notch is located, of the piston, a screw hole is further formed in the piston, the screw hole is vertically formed and penetrates through the notch, the screw hole is formed in the perpendicular bisector of the notch, and a self-locking bolt is arranged in the screw hole. According to the self-locking anti-loosening hydraulic nut, the piston above the notch can be pressed downwards through the self-locking bolt, retraction is reduced, the locking precision is improved, the hydraulic nut is prevented from loosening, the service life of the hydraulic nut is prolonged, the screw hole is formed in the perpendicular bisector of the notch, and the piston at the pressing position is stressed in a balanced mode.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of hydraulic nut, especially to a self-locking and anti-loose hydraulic nut. BACKGROUND

[0002] The hydraulic nut is used for the bolt that needs to be frequently disassembled, the pre-tightening of the super large bolt, the locking of the large workpiece and the like occasions.

[0003] Due to the compact working condition and limited space of the nuclear power engineering, if the mechanical nut is used, the pre-tightening is difficult due to the need of large space for the disassembly and assembly of the nut, so it is more appropriate to use the hydraulic nut.

[0004] The hydraulic nut is mainly composed of three parts, including a hydraulic cylinder, a piston and a locking nut.

[0005] Step 1: the piston in the hydraulic cylinder is pushed by the super high pressure oil to directly apply an external force to the bolt, so that the bolt subjected to the force is stretched in the elastic deformation zone thereof;

[0006] Step 2: the locking nut is tightened after the bolt is stretched, so that the bolt is locked at the stretched position by the locking nut, and then the hydraulic cylinder is depressurized, and the hydraulic oil flows back to the pump station.

[0007] In the actual use process of the hydraulic nut, there is a gap between the threaded connection part of the locking nut and the piston.

[0008] In the above step 1, the bolt is stretched to a length that just meets the pre-tightening force, and after the hydraulic cylinder is depressurized, the stretched bolt will shrink due to the gap between the locking nut and the piston and the negative pressure state of the hydraulic cylinder, resulting in that the actual pre-tightening force is less than the preset pre-tightening force, the locking precision is reduced, and the locking is unreliable. SUMMARY

[0009] The utility model aims at the demand for improving the locking precision of the hydraulic nut for assembling the bolt on the basis of the existing hydraulic nut, and constructs a self-locking and anti-loose hydraulic nut.

[0010] The self-locking hydraulic nut comprises a hydraulic cylinder, a piston and a locking nut, an oil cavity of the hydraulic cylinder is connected with an external pump station through a flow channel, the piston is located in the oil cavity of the hydraulic cylinder and is in sliding connection with the hydraulic cylinder, the piston is in annular structure and is provided with an inner thread and an outer thread, the piston is connected with a bolt through the inner thread, and the piston is connected with the locking nut through the outer thread, characterized in that a notch is arranged at an upward position of the piston, the notch is in arc shape, a median line of the notch passes through a midpoint of a cross section of the piston at the position, a screw hole is further arranged on the piston, the screw hole is vertically arranged and penetrates through the notch, the screw hole is arranged on the median line of the notch, and a self-locking bolt is arranged in the screw hole.

[0011] The self-locking bolt presses the piston above the notch downward, the outer thread of the piston at the pressed position is deformed, the gap between the piston and the locking nut is reduced, the retraction of the piston when the hydraulic cylinder is depressurized is reduced, the locking precision is improved, the looseness of the hydraulic nut during use is further reduced, and the service life of the hydraulic nut is increased.

[0012] The screw hole is arranged on the median line of the notch, so that the part of the piston for self-locking is balanced in force on both sides of the median line.

[0013] Further, the arc shape comprises a chord and an arc, a midpoint a of the chord and a midpoint b of the arc, a straight line obtained by connecting the two points a and b is x, the unilateral wall thickness of the piston is h, the radius of the cross section of the piston is r,

[0014] h < r < x < 2r-h.

[0015] The piston for self-locking will not cause poor locking effect due to too small locking area, nor will it cause the piston to break due to too large notch.

[0016] Further, the notch is horizontally arranged.

[0017] Further, the rotation center line of the self-locking bolt is parallel to the rotation center line of the piston, and the rotation center line of the self-locking bolt is perpendicular to the horizontal plane of the notch.

[0018] Further, the hydraulic cylinder is provided with an oil cavity and a linkage cavity, the oil cavity is in communication with the linkage cavity, the oil cavity is located above the linkage cavity, and the diameter of the oil cavity is greater than the diameter of the linkage cavity.

[0019] Further, the piston comprises an upper part and a lower part, the diameter of the upper part is larger than that of the lower part, the outer side of the upper part is provided with a sliding piece, the sliding piece is in sliding connection with the inner wall of the oil cavity, the outer thread of the piston is arranged on the outer side of the upper part, the outer thread of the piston is located above the sliding piece, the lower part of the piston is in sliding connection with the linkage cavity,

[0020] The middle part of the piston is provided with a connecting hole penetrating upward and downward, the inner thread is arranged on the hole wall of the connecting hole, and the diameter of the connecting hole is equal to that of the bolt,

[0021] The piston is provided with a groove, and the groove is communicated with the flow channel.

[0022] Further, the lower side of the sliding piece is provided with a sealing piece, and the sealing piece is a V-shaped spring energy storage ring. Compared with the common O-shaped sealing ring, the V-shaped spring energy storage ring has better sealing effect and longer service life, and can guarantee a service life of 50 years.

[0023] Further, the locking nut is provided with a plurality of connecting holes for connecting a screwing tool.

[0024] Further, the hydraulic nut is made of non-magnetic material, which can guarantee the mechanical properties of the hydraulic nut.

[0025] The self-locking hydraulic nut has the advantages that the piston above the notch can be pressed downward by the self-locking bolt, the outer thread of the piston at the pressing position is deformed, the gap between the piston and the locking nut is reduced, the retraction of the piston during pressure relief of the hydraulic cylinder is reduced, the locking precision is improved, the loosening of the hydraulic nut during use is prevented, the service life of the hydraulic nut is increased, the screw hole is arranged on the median line of the notch, the piston at the pressing position is balanced in force, and the like.

[0026] The above description is only a summary of the technical scheme of the utility model, in order to more clearly understand the technical means of the utility model, which can be implemented according to the content of the specification, and in order to let the above and other purposes, characteristics and advantages of the utility model can be more obvious and easy to understand, the following preferred embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor according to these drawings;

[0028] Figure 1It is the whole structure schematic view of a specific example of the hydraulic nut of the utility model;

[0029] Figure 2 It is Figure 1 The cross section structure schematic view of the piston at the notch;

[0030] Figure 3 It is the structure schematic view of the hydraulic cylinder in a specific example of the hydraulic nut of the utility model;

[0031] Figure 4 It is the structure schematic view of the piston in a specific example of the hydraulic nut of the utility model;

[0032] Figure 5 It is Figure 2 The structure enlarged view of A in

[0033] Figure 6 It is the structure schematic view of the locking nut in a specific example of the hydraulic nut of the utility model;

[0034] Figure 7 It is the cross section structure schematic view of the piston at the notch in a specific example of the hydraulic nut of the utility model;

[0035] In the figure: 102, hydraulic cylinder; 103, interface; 104, piston; 105, locking nut; 106, connecting hole; 109, linkage cavity; 110, flow channel; 111, oil cavity; 112, self-locking bolt; 113, screw hole; 114, notch; 115, sliding piece; 117, connecting hole; 120, annular groove; 121, V-shaped spring energy storage ring. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical schemes and beneficial effects solved by the utility model more clearly understood, the utility model is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.

[0037] The utility model is further described in combination with the drawings.

[0038] As Figure 1 And Figure 2 Indicated, the hydraulic nut described in the embodiment is made of non-magnetic material, the hydraulic nut includes hydraulic cylinder 102, piston 104 and locking nut 105, hydraulic cylinder 102 is connected with hydraulic oil interface 103, and hydraulic cylinder 102 is connected with external pump station through interface 103, piston 104 is arranged in hydraulic cylinder 102, and piston 104 is slidably connected with hydraulic cylinder 102, piston 104 is connected with locking nut 105 through thread, and self-locking bolt 112 is arranged on piston 104.

[0039] As shown in Figure 2 and Figure 3 , the hydraulic cylinder 102 is provided with an oil cavity 111 and a linkage cavity 109, the oil cavity 111 and the linkage cavity 109 are communicated, the diameter of the oil cavity 111 is larger than that of the linkage cavity 109, the oil cavity 111 is located above the linkage cavity 109, the hydraulic cylinder 102 is provided with a flow channel 110, the flow channel 110 includes a horizontal section and a vertical section, the horizontal section of the flow channel 110 is connected with the interface 103, the vertical section of the flow channel 110 is communicated with the oil cavity 111, and the horizontal section of the flow channel 110 and the vertical section of the flow channel 110 are communicated.

[0040] As shown in Figure 2 and Figure 4 , the piston 104 includes an upper part and a lower part, the diameter of the upper part is larger than that of the lower part, the piston 104 is provided with a connecting hole 106 penetrating upward and downward in the middle part, the hole wall of the connecting hole 106 is provided with an internal thread, the internal thread is used for connecting with a bolt, and the diameter of the connecting hole 106 is equal to that of the bolt, the outer side of the upper part of the piston 104 is provided with an external thread, and the external thread is used for connecting with the lock nut 105. The lower part of the piston 104 is in sliding connection with the linkage cavity 109.

[0041] The upper position of the piston 104 is provided with a notch 114, and the notch 114 is horizontally arranged. The piston 104 is further provided with a threaded hole 113, and the threaded hole 113 is vertically arranged and penetrates the notch 114. The self-locking bolt 112 is arranged at the threaded hole 113.

[0042] As shown in Figure 2 and Figure 5 , the piston 104 is provided with a sliding piece 115 on the outer side, the sliding piece 115 is in sliding connection with the inner wall of the oil cavity 111, the external thread arranged on the piston 104 is located above the sliding piece 115, and a V-shaped spring energy storage ring 121 is arranged below the sliding piece 115.

[0043] The lower end surface of the upper part of the piston 104 is provided with an annular groove 120, and the annular groove 120 is communicated with the flow channel 110.

[0044] As shown in Figure 2 and Figure 7 , the notch 114 is arc-shaped, the arc-shaped notch includes a chord and an arc, a midpoint a of the chord and a midpoint b of the arc, a straight line obtained by connecting the two points a and b is x, and a straight line where the straight line x is located is the perpendicular bisector of the arc-shaped notch, that is, the straight line where the straight line x is located is the perpendicular bisector of the notch 114, and the perpendicular bisector passes through the midpoint O of the cross section of the piston 104. The threaded hole 113 is arranged on the perpendicular bisector.

[0045] The unilateral wall thickness of the piston 104 is h, the radius of the cross section of the piston 104 is r, h < r < x < 2r-h.

[0046] AsFigure 6 As shown in the figure, the locking nut 105 is provided with six connecting holes 117 for connecting the screwing tool.

[0047] In the use of hydraulic nut installation bolt,

[0048] a, the hydraulic nut is connected with the bolt through the internal thread on the piston 104, the piston 104 in the hydraulic cylinder 102 is pushed by the ultra-high pressure oil, the bolt subjected to the force is stretched in the elastic deformation zone thereof;

[0049] b, the locking nut 105 is screwed, so that the bolt is locked in the stretched position;

[0050] c, the self-locking bolt 112 is screwed to make the piston 104 above the notch 114 to be pressed down, the displacement deformation of the external thread at the pressed-down position is generated, the gap between the external thread and the internal thread in the locking nut 105 is reduced, and the retraction of the piston 104 is also reduced after the hydraulic cylinder 102 is depressurized.

[0051] The above is only the preferred specific implementation mode of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A self-locking and anti-loose hydraulic nut, comprising a hydraulic cylinder, a piston and a locking nut, an oil cavity of the hydraulic cylinder is connected with an external pump station through a flow channel, the piston is located in the oil cavity of the hydraulic cylinder and is in sliding connection with the hydraulic cylinder, the piston is in ring structure and is provided with an inner thread and an outer thread, the piston is connected with a bolt through the inner thread, and the piston is connected with the locking nut through the outer thread, characterized in that, The position of the piston is provided with a notch, the notch is arcuate, the median line of the notch passes through the midpoint of the cross section of the piston, the piston is further provided with a screw hole, the screw hole is vertically arranged and penetrates the notch, the screw hole is arranged on the median line of the notch, and a self-locking bolt is arranged in the screw hole.

2. The self-locking hydraulic nut according to claim 1, wherein The arcuate notch comprises a chord and an arc, the midpoint a of the chord and the midpoint b of the arc, the straight line obtained by connecting the two points a and b is x, the single-sided wall thickness of the piston is h, the radius of the cross section of the piston is r, h < r < x < 2r-h.

3. The self-locking hydraulic nut of claim 1, wherein The notch is horizontally arranged.

4. The self-locking, self-tightening hydraulic nut of claim 1, wherein, The rotation center line of the self-locking bolt is parallel to the rotation center line of the piston, and the rotation center line of the self-locking bolt is perpendicular to the horizontal plane of the notch.

5. The self-locking hydraulic nut of claim 1, wherein The hydraulic cylinder is provided with an oil cavity and a linkage cavity, the oil cavity is communicated with the linkage cavity, the oil cavity is located above the linkage cavity, and the diameter of the oil cavity is greater than that of the linkage cavity.

6. The self-locking, self-tightening hydraulic nut of claim 1, wherein, The piston comprises an upper part and a lower part, the diameter of the upper part is greater than that of the lower part, the outer side of the upper part is provided with a sliding piece, the sliding piece is in sliding connection with the inner wall of the oil cavity, the external thread of the piston is arranged on the outer side of the upper part, the external thread of the piston is located above the sliding piece, and the lower part is in sliding connection with the linkage cavity.

7. The self-locking, self-tightening hydraulic nut of claim 6, wherein, The middle part of the piston is provided with a connecting hole penetrating the upper and lower parts, and the internal thread is arranged on the hole wall of the connecting hole, and the diameter of the connecting hole is equal to that of the bolt.

8. The self-locking, self-tightening hydraulic nut of claim 1, wherein, The piston is provided with a recess, and the recess is communicated with the flow channel.

9. The self-locking, self-tightening hydraulic nut of claim 6, wherein, The lower part of the sliding piece is provided with a sealing piece, and the sealing piece is a V-shaped spring energy storage ring.

10. The self-locking, self-tightening hydraulic nut of claim 1, wherein, The locking nut is provided with a plurality of connecting holes for connecting the screwing tool.

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