Pipe connection device

Abstract

The application provides a pipeline connecting device, which comprises a first connecting pipe, a second connecting pipe, a nut, and a connecting head. The nut comprises a main body part, the outer circumferential surface of the main body part is provided with two or more first conical surfaces, an operation part recessed towards the central axis direction of the nut is arranged between each first conical surface, the first end of the operation part intersects with the first conical surface at a first edge line, at least one section of the second end of the operation part gradually decreases in outer diameter and forms a convex surface with the adjacent first conical surface, the convex surface intersects with the first conical surface at a second edge line, the convex surface intersects with the operation part at a third edge line, and in any cross section of the operation part, the distance between the surface of the operation part and the central axis of the nut is in an increasing state along the direction close to the first end.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration systems, in particular to a pipe connection structure for a refrigeration system. BACKGROUND

[0002] In an air conditioning system, a pipe connection device is mainly used to connect the pipes of a refrigeration system, which generally adopts a pipe nut and a pipe joint to realize sealing and fixing of two pipes of the refrigeration system. Figure 1 As shown in the background art, Figure 1 A common pipe connection device in the background art comprises a first pipe 1', a second pipe 2', a connecting head 3' and a pipe nut 4'. The pipe nut 4' is provided with internal threads, and the pipe joint 3' is provided with external threads. The pipe nut and the pipe joint are connected through threads. The pipe nut is provided with a hexagonal operating surface 41'. During operation, the operating surface 41' is clamped by a wrench and rotated clockwise to tighten the pipe nut in the forward direction to achieve fixation. This pipe connection device can be tightened in the forward direction and loosened in the reverse direction. In recent years, due to environmental protection needs, air conditioning refrigerants have gradually switched to R32 and other more flammable refrigerants. In order to prevent accidents caused by improper operation, the national standard requires that non-professionals cannot disassemble air conditioners using such refrigerants. Therefore, it is a technical problem for those skilled in the art to design a pipe connection device that is not easily disassembled. SUMMARY

[0003] The purpose of the present application is to provide a new pipe connection device that cannot be easily disassembled by a wrench or other tools.

[0004] To this end, the present application provides a pipe connection device comprising a first pipe, a second pipe, a nut, and a connecting head. The first pipe is fixedly connected to the connecting head, the connecting head is threadedly connected to the nut, and the connecting head, the nut and the second pipe are limited and fixedly connected. The nut comprises a main body portion, the outer peripheral surface of the main body portion is provided with two or more first conical surfaces, an operating portion recessed towards the center axis of the nut is arranged between each first conical surface, the first end of the operating portion intersects the first conical surface at a first edge line, at least one section of the second end of the operating portion gradually decreases in diameter and forms a convex surface with the adjacent first conical surface, the convex surface intersects the first conical surface at a second edge line, and the convex surface intersects the operating portion at a third edge line. In any cross section located in the operating portion, the distance between the surface of the operating portion and the center axis of the nut increases in the direction approaching the first end.

[0005] The pipeline connecting device provided by the application can prevent the wrench from sliding along the surface of the operating part when the wrench is used to hold the nut and loosen the nut in the counterclockwise direction, so that the nut cannot be easily disassembled. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 A schematic structural view of a pipeline connecting device for background art;

[0007] Figure 2 A perspective view of a first embodiment of the pipeline connecting device provided by the application;

[0008] Figure 3 A sectional view of the first embodiment of the pipeline connecting device provided by the application;

[0009] Figure 4 A schematic structural view of the nut of the first embodiment;

[0010] Figure 5 A sectional view of the nut of the first embodiment;

[0011] Figure 6 A front view of the nut of the first embodiment;

[0012] Figure 7 A view of A-A of Figure 6 ;

[0013] Figure 8 A schematic structural view of the nut provided by the second embodiment;

[0014] Figure 9 A schematic structural view of the nut provided by the third embodiment;

[0015] Figure 10 A schematic structural view of the nut provided by the fourth embodiment; DETAILED DESCRIPTION

[0016] In order to enable the person skilled in the art to better understand the application scheme, the application will be further described in detail below in combination with the drawings and specific embodiments.

[0017] It should be pointed out that the orientation words left, right, up and down mentioned in this paper are defined based on the corresponding drawings shown in the specification, and the use of the orientation words is only for the convenience of describing the technical scheme, and it should be understood that the use of the orientation words does not constitute a limitation on the protection scope.

[0018] Please refer to Figure 2 , Figure 3 , Figure 2 is a perspective view of a pipeline connecting device provided by the application, Figure 3is a sectional view of a pipeline connecting device provided by the present application.

[0019] The pipeline connecting device comprises a first connecting pipe 101, a second connecting pipe 102, a nut 1, and a connecting head 2. The first connecting pipe 101 is connected to the connecting head 2 by welding. The connecting head 2 is provided with external threads 202. The inner circumferential wall of the nut 1 is provided with a threaded portion 40. The threaded portion 40 is used to cooperate with the external threads 202 of the connecting head 2 to achieve fixation. The main body of the nut 1 is provided with a through hole portion 60. The second connecting pipe 102 is inserted into the channel formed by the through hole portion 60. The inner circumferential wall of the nut 1 is further provided with an inner tapered surface portion 50. Correspondingly, one end of the second connecting pipe 102 is provided with an expanded portion 1021. The connecting head 2 is provided with an outer tapered surface portion 201. When the nut 1 cooperates with the connecting head 2, the inner tapered surface portion 50 and the outer tapered surface portion 201 can cooperate with the expanded portion 1021 of the second connecting pipe and clamp at least part of the expanded portion 1021 therebetween. Specifically, the second connecting pipe 102 can be inserted into the channel formed by the through hole portion 60 first. Then, the end of the second connecting pipe 102 is expanded to form the expanded portion 1021. Then, the nut 1 is tightened to tightly connect the nut and the connecting head. The expanded portion 1021 is tightly attached to the tapered surface portion 50 to prevent the second connecting pipe from being separated from the pipeline connecting device, thereby achieving the fixed connection between the first connecting pipe 101 and the second connecting pipe 102.

[0020] It should be noted that the present application mainly improves the external structure of the nut 1 to achieve the purpose that the pipeline connecting device cannot be easily disassembled. The above description of the internal structure of the pipeline connecting device is only for the understanding of the technical solution by those skilled in the art and does not constitute a limitation on the internal structure of the pipeline connecting device. Those skilled in the art can make various adaptive changes or equivalent replacements to the internal structure of the pipeline connecting device without departing from the concept of the present application.

[0021] Please refer to Figures 4-7 , Figure 4 is a schematic view of the nut structure of the first embodiment, Figure 5 is a sectional view of the nut of the first embodiment. Figure 6 is a front view of the nut of the first embodiment, Figure 7 is the A-A view of Figure 6 .

[0022] The outer peripheral wall of the nut is provided with a first end portion 3 which is generally cylindrical in shape and has a first surface 30 formed on the surface thereof, and has an outer diameter D1. A main body portion 4 is provided along the axial direction of the first end portion 3, and is used for tightening the nut by a wrench or the like. The overall profile of the main body portion 4 is generally frustoconical, and a plurality of first frustoconical surfaces 10 are distributed on the outer peripheral surface thereof, which generally define a virtual frustoconical surface, i.e. the edge lines of the plurality of first frustoconical surfaces 10 in any cross section are located on the same circle, as shown in Figure 6 The outer diameter of the first frustoconical surface 10 gradually decreases towards the side away from the first end portion 3, i.e. the outer diameter of the first frustoconical surface 10 at the side adjacent to the first end portion 3 A is greater than the outer diameter of the first frustoconical surface 10 at the side away from the first end portion 3 B, and the outer diameter of the first frustoconical surface 10 at any position is D2, and D1≥D2 is satisfied. If the outer diameter of the first frustoconical surface 10 at any position is greater than the outer diameter of the first end portion 3, the wrench may touch or abut against the fulcrum formed between the second edge line 22 and the first end portion 3 when the nut is tightened in the counterclockwise direction, so that the nut is loosened.

[0023] The nut 1 also has a second end portion 5 which is located at the other end of the main body portion 4, i.e. the first end portion 3 and the second end portion 5 are respectively located at the two sides of the main body portion 4.

[0024] The outer edge of the main body portion 4, except for the first frustoconical surface 10, is recessed towards the central axis S, and forms at least one pair of operation portions 20 which are symmetrically distributed with respect to the central axis S. The first end of the operation portion 20 intersects the first frustoconical surface 10 in the clockwise direction, as shown in Figure 3 , to form a first edge line 26, and the operation portion 20 gradually decreases in outer diameter in at least one section in the counterclockwise direction, as shown in Figure 3 , so that a certain height difference is formed with the adjacent other frustoconical surface 10, and a convex surface 21 is formed therebetween, which intersects the first frustoconical surface at a second edge line 22 and intersects the operation portion 20 at a third edge line 23.

[0025] In the present embodiment, the operation portion 20 includes clamping portions 25, and specifically, the surface of the clamping portion 25 is planar, and constitutes a part of the surface of the operation portion 20. The clamping portion 25 having a planar surface is beneficial for clamping by a wrench or the like to operate the tightening of the nut. In the present embodiment, the number of clamping portions 25 is four, which are divided into two pairs, and the surfaces of each pair of clamping portions 25 are parallel to each other, which is beneficial for clamping by a wrench.

[0026] The distance between the surface of the operation portion 20 and the central axis S of the nut in any cross section of the operation portion 20 is in an increasing state in the direction of tightening the nut (i.e. the clockwise direction). Please refer to Figure 7 , Figure 7is a cross-sectional view of one of the cross sections A-A, taken as an example of one of the frustoconical faces 10, and taken in a plane perpendicular to the central axis of the nut, the operating portion 20 is formed in the cross section as a profile line CD, wherein C is the intersection of the profile line CD and the third edge line 23, corresponding to the second end of the operating portion, and D is the intersection of the profile line CD and the first edge line 26, corresponding to the first end of the operating portion, and the distance from the point C to the central axis S of the nut is Rc, and the distance from the point D to the central axis S of the nut is Rd, and it is satisfied that Rc < Rd. In the profile line CD, two points E and F are taken arbitrarily, as shown in Figure 7 , the point E is close to the point C, and the point F is close to the point D, and the distance from the point E to the central axis S of the nut is Re, and the distance from the point F to the central axis S of the nut is Rf, and it is satisfied that Rc < Re < Rf < Rd. In this way, when the wrench is clamped to the clamping portion 25 and rotated in the clockwise direction to tighten the nut 1, the clamping distance gradually increases, so that the nut is easily rotated by the wrench to achieve the clamping purpose. Conversely, if the wrench is clamped to the clamping portion 25 and rotated in the counterclockwise direction, the clamping distance gradually decreases, which causes the wrench to slide along the surface of the operating portion 20 in the circumferential direction, i.e. the nut cannot be loosened by the wrench.

[0027] As a specific embodiment, the operating portion 20 is a curved surface portion 24 except that the surface of the clamping portion 25 is planar. In this embodiment, the surface of the curved surface portion 24 is a cylindrical surface, which is convenient for forging and forming. The curved surface portion 24 intersects with the surface of the clamping portion 25 at an intersection line 27.

[0028] As shown in Figure 4 and Figure 6 , the boss surface 21 gradually inclines in the counterclockwise direction as shown in Figure 4 , i.e. in a virtual plane, the extension line of the first edge line 22 and the projection of the central axis on the virtual plane form an angle α. In this way, if the wrench is clamped to the clamping portion 25 and rotated in the counterclockwise direction, the wrench will slide along the surface of the operating portion 20 in the circumferential direction, and also slide along the second edge line 22 in the axial direction, further preventing the wrench from effectively loosening the nut, so as to achieve the purpose that the nut cannot be easily disassembled by using a wrench or other tools.

[0029] Please refer to Figure 8 , Figure 8 is a schematic view of the nut structure provided by the second embodiment. In order to facilitate the explanation of the differences between the first embodiment and the second embodiment, the same reference numerals are used for the parts with the same structure and function in the two embodiments.

[0030] The outer peripheral wall of the nut is provided with a first end portion 3 which is generally cylindrical in shape and has a first surface 30 formed on the surface thereof, and has an outer diameter D1. The nut 1 also has a second end portion 5 which is located at the other end of the main body portion 4, i.e. the first end portion 3 and the second end portion 5 are located at two opposite sides of the main body portion 4. The main body portion 4 can be used for a wrench or the like to tighten the nut. The overall profile of the main body portion 4 is generally frustoconical in shape, and a plurality of first frustoconical surfaces 10 are distributed on the outer peripheral surface thereof, which generally define a virtual frustoconical surface, i.e. the edge lines of the plurality of first frustoconical surfaces 10 in any cross section are located on the same circle. Among them, the outer diameter of the first frustoconical surface 10 gradually decreases towards the side away from the first end portion 3, i.e. the outer diameter of the first frustoconical surface 10 adjacent to the first end portion 3 A is greater than the outer diameter of the first frustoconical surface 10 away from the first end portion 3 B, and the outer diameter of any position of the first frustoconical surface 10 is D2, which satisfies: D1≥D2. If the outer diameter of any position of the first frustoconical surface 10 is greater than the outer diameter of the first end portion 3, the wrench may touch or abut on the fulcrum formed between the first edge line 22 and the first end portion 3 when tightening the nut in the counterclockwise direction, so that the nut is loosened.

[0031] The outer edge of the main body portion 4 is recessed towards the center axis S except the first frustoconical surface 10, and forms at least one pair of operation portions 201 which are symmetrically distributed with respect to the center axis S, and the outer surface of the operation portion 201 intersects with the first frustoconical surface 10 in the clockwise direction as shown to form a first edge line 26, and the operation portion 201 gradually reduces the outer diameter in at least one section in the counterclockwise direction as shown, so as to form a certain height difference with the adjacent other frustoconical surface 10, and a convex surface 21 is formed therebetween, the convex surface 21 intersects with the first frustoconical surface at a second edge line 22, and intersects with the operation portion 201 at a third edge line 23. Figure 8 Figure 3 The outer edge of the main body portion 4 is recessed towards the center axis S except the first frustoconical surface 10, and forms at least one pair of operation portions 201 which are symmetrically distributed with respect to the center axis S, and the outer surface of the operation portion 201 intersects with the first frustoconical surface 10 in the clockwise direction as shown to form a first edge line 26, and the operation portion 201 gradually reduces the outer diameter in at least one section in the counterclockwise direction as shown, so as to form a certain height difference with the adjacent other frustoconical surface 10, and a convex surface 21 is formed therebetween, the convex surface 21 intersects with the first frustoconical surface at a second edge line 22, and intersects with the operation portion 201 at a third edge line 23.

[0032] ​In the present embodiment, the operation portion 201 has a surface 241 which is entirely curved. In any cross section of the operation portion 201, the distance between the surface of the operation portion 201 and the center axis S of the nut is increasing in the direction of tightening the nut, i.e. in the clockwise direction. Of course, the operation portion can also be flat near the right side of the drawing, i.e. the first end of the operation portion can be flat and the second end can be curved. The flat surface of the operation portion is advantageous for clamping the tool, and the smoothly transitioning curved surface is advantageous for the tool to slide off easily along the curved surface when the tool is rotated anticlockwise after being clamped. In this way, when the nut 1 is tightened by using a wrench to clamp the operation portion 201 and rotate it in the clockwise direction, the clamping distance gradually increases, so that the nut is easily rotated by the wrench to achieve the clamping purpose. Conversely, when the nut is loosened by using a wrench to clamp the operation portion 201 and rotate it in the anticlockwise direction, the clamping distance gradually decreases, so that the wrench slides off along the surface of the operation portion 201 in the circumferential direction, i.e. the nut cannot be loosened by the wrench. Similarly to the first embodiment, the convex surface 21 can also be gradually inclined in the anticlockwise direction. In this way, when the nut is loosened by using a wrench to clamp the operation portion 201 and rotate it in the anticlockwise direction, the wrench slides off along the surface of the operation portion 201 in the circumferential direction and also slides off axially along the second edge line 22, so that the wrench cannot effectively loosen the nut, to achieve the purpose that the nut cannot be easily disassembled by using a wrench or the like.

[0033] Please refer to Figure 9 , Figure 9 is a schematic view of the nut structure of the third embodiment of the present application. The difference between the present embodiment and the first embodiment is that the operation portion 202 comprises a clamping portion 252 and a curved portion 242, wherein the surface of the curved portion 242 does not directly intersect the surface of the clamping portion 252, but there is a certain height difference, i.e. the outer diameter of any part of the curved portion 242 is smaller than the outer diameter of the clamping portion 252, so that a step portion 212 is formed between them. The number of operation portions 202 is four, and they are divided into two pairs. Each pair of operation portions 202 is symmetrically arranged on the outer peripheral wall of the main body portion 4. Similarly, this structure also satisfies that the distance between the surface of the operation portion 201 and the center axis S of the nut is increasing in the direction of tightening the nut, i.e. in the clockwise direction. When the nut is tightened, the clamping distance gradually increases, so that the nut is easily rotated by the wrench to achieve the clamping purpose. Conversely, when the nut is loosened by using a wrench to clamp the operation portion 202 and rotate it in the anticlockwise direction, the clamping distance gradually decreases, so that the wrench slides off along the surface of the operation portion 202 in the circumferential direction, i.e. the nut cannot be loosened by the wrench.

[0034] Please refer to Figure 10 , Figure 10Fig. 4 is a schematic view of a nut structure according to a fourth embodiment of the present application. The fourth embodiment differs from the third embodiment in that the number of operation portions 202 is two and the operation portions 202 are symmetrically distributed on the outer peripheral wall of the main body portion 4. The remaining structure can be understood with reference to the third embodiment. The fourth embodiment also achieves the effect that when the nut is loosened in the reverse direction, the wrench easily slides off along the surface of the operation portion in the circumferential direction. Further, when the inclined convex surface is provided, the wrench easily slides off along the convex surface in the axial direction, thereby achieving the effect that the nut is not easily removed.

[0035] The ordinal numbers "first", "second", etc. appearing in the specification of the present application are used only for the purpose of distinguishing different components, and do not mean that there is a specific sequence between the components. The "plane" described in the specification is relatively flat with respect to a curved surface, and does not mean an absolute plane.

[0036] The valve device provided by the present application has been described in detail above. The principles and embodiments of the present application are described by applying specific examples in this document. The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, a number of improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A pipeline connecting device, comprising a first connecting pipe, a second connecting pipe, a nut, a connecting head, the first connecting pipe is fixedly connected with the connecting head, the connecting head is threadedly connected with the nut, the connecting head, the nut and the second connecting pipe are limited and fixedly connected, characterized in that, The nut comprises a main body part, an outer circumferential surface of the main body part is provided with two or more first conical surfaces, an operation part recessed towards a central axis direction of the nut is arranged between each of the first conical surfaces, a first end of the operation part intersects the first conical surface at a first edge line, an outer diameter of a second end of the operation part gradually decreases at least in a section, and forms a convex surface with the adjacent first conical surface, the convex surface intersects the first conical surface at a second edge line, the convex surface intersects the operation part at a third edge line, in any cross section of the operation part, a distance between a surface of the operation part and the central axis of the nut is in an increasing state along a direction close to the first end.

2. The plumbing coupling according to Claim 1, wherein, The nut comprises a first end part and a second end part, the first end part is located at one side of the main body part, the second end part is located at the other side of the main body part, an outer diameter D1 of the first end part is greater than or equal to an outer diameter D2 of any position of the first conical surface.

3. The plumbing coupling according to Claim 1, wherein, An extension line of the first edge line and a projection of the central axis of the nut on a plane form an included angle α, in a counterclockwise direction of unscrewing the nut, the convex surface gradually inclines.

4. A pipe connection device according to any one of claims 1-3, characterised in that The operation part comprises a clamping part and a curved surface part, a surface of the clamping part is a plane, and the number of the clamping parts is one pair or more, a surface of each pair of the clamping parts is parallel to each other.

5. A pipe connection device as claimed in claim 4, characterised in that A surface of the curved surface part is a cylindrical surface, and the cylindrical surface intersects the surface of the clamping part at an intersection line, an outer diameter of the curved surface part at a side close to the convex surface is smaller than an outer diameter of the first conical surface.

6. A pipe connection device according to any one of claims 1-3, characterized in that The operation part has a surface in a whole curved surface shape, in any cross section of the operation part, a distance between the surface of the operation part and the central axis of the nut is in an increasing state along a direction close to the first end.

7. A pipe connection device according to any one of claims 1-3, characterized in that A surface of the first end of the operation part is a plane, a surface of the second end of the operation part is a curved surface, and the plane and the curved surface are smoothly connected.

8. A pipe connection device according to any one of claims 1-3, characterized in that The operation part comprises a clamping part and a curved surface part, a surface of the curved surface part has a height difference with a surface of the clamping part, an outer diameter of any part of the curved surface part is smaller than an outer diameter of the clamping part, and a stepped part is formed between the curved surface part and the clamping part.

9. A pipe connection device according to any one of claims 1-3, characterized in that The number of the operation parts is two, and the operation parts are symmetrically distributed on an outer circumferential wall of the main body part.

Images