Constraint type corrugated pipe expansion joint capable of compensating axial displacement
Technical Field
The utility model relates to an expansion joint technical field, what specifically say so is a can compensate about type bellows expansion joint of axial displacement.
Background
In order to prevent the pressure thrust generated by the unbalanced corrugated pipe expansion joint from acting on the equipment to cause damage to an equipment base and influence the normal operation of the equipment, the constrained or straight pipe pressure balanced corrugated pipe expansion joint is usually selected to constrain or balance the pressure thrust. The existing conventional constraint type bellows expansion joint has a hinge type and a compound pull rod type. The expansion joint of the hinge type (figure 1) is composed of a corrugated pipe, an end pipe and a group of constraint structural parts and is mainly used for absorbing angular displacement and constraining the pressure thrust of the corrugated pipe. The tie-rod type expansion joint (fig. 2) is composed of a working corrugated pipe, an end pipe and a group of constraint structural members, and is mainly used for absorbing transverse displacement and constraining the pressure thrust of the corrugated pipe.
The conventional straight pipe pressure balance type corrugated pipe expansion joint is divided into external pressure and internal pressure. The external pressure type straight pipe pressure balance type expansion joint (figure 3) is composed of a group of working corrugated pipes and a group of balance corrugated pipes, and is mainly used for absorbing axial displacement and balancing the pressure thrust of the corrugated pipes. The internal pressure type straight pipe pressure balance type expansion joint (figure 4) is composed of two working corrugated pipes, a balance corrugated pipe in the middle, a pull rod, an end plate and other structural members, and is mainly used for absorbing axial displacement and balancing pressure thrust of the corrugated pipes.
The conventional structure constraint type corrugated expansion joint can only compensate angular displacement and transverse displacement, cannot compensate axial displacement, adopts a balance type corrugated expansion joint to compensate axial displacement, balances pressure thrust, needs to add a group of balance waves, and increases corresponding constraint structural parts simultaneously, so that the overall outer diameter of the expansion joint is too large, the equipment weight is heavier, and the manufacturing cost is relatively higher.
SUMMERY OF THE UTILITY MODEL
In order to solve the technical problem, the utility model provides a can compensate about type bellows expansion joint of axial displacement has solved the problem that conventional about type bellows expansion joint can not compensate axial displacement, straight tube pressure balance type bellows expansion joint external diameter is too big, weight is heavier, manufacturing cost is high.
In order to realize the technical purpose, the adopted technical scheme is as follows: a constrained corrugated pipe expansion joint capable of compensating axial displacement comprises a first flange, a corrugated pipe, a second flange and a constrained member, wherein the first flange and the second flange are welded at two ends of the corrugated pipe respectively, a plurality of groups of constrained members are uniformly distributed on the outer side of the corrugated pipe in the circumferential direction, a plurality of groups of first compensated cavities with equal diameters are formed in the first flange, one end of each first compensated cavity is communicated with an inner cavity of the expansion joint, the other end of each first compensated cavity is communicated with external air, a first displacement compensation sliding port communicated with the first compensated cavity is formed in the inner end face of the first flange, a plurality of groups of second compensated cavities with equal diameters are formed in the second flange, and a second displacement compensation sliding port communicated with the second compensated cavities is formed in the inner end face of the second flange; the first compensation cavities and the second compensation cavities are arranged in one-to-one correspondence, the first compensation cavities and the second compensation cavities are inclined towards the middle of the expansion joint, and a constraint component is arranged between each group of correspondingly arranged first compensation cavities and each group of correspondingly arranged second compensation cavities;
the restraint member comprises a first piston, a second piston and a pull rod, the first piston is arranged in the first compensation cavity in a sliding fit mode, the second piston is arranged in the second compensation cavity in a sliding fit mode, the pull rod is arranged in an inclined mode, one end of the pull rod penetrates through the first displacement compensation sliding opening and then is connected with the first piston, and the other end of the pull rod penetrates through the second displacement compensation sliding opening and then is connected with the second piston;
the expansion joint satisfies the following conditions:
wherein A is the cross-sectional area of the first piston; a. the
cIs the effective area of the corrugated pipe; n is the total number of constraining members; alpha is the included angle between the first compensation cavity and the first flange plane, the included angle between the second compensation cavity and the second flange plane, the included angle between the pull rod and the first flange axis and the included angle between the pull rod and the second flange axis.
The first piston is circular in cross-section.
The second piston is circular in cross-section.
And a sealing ring is sleeved on the first piston in one side of the first compensation cavity communicated with the inner cavity of the expansion joint.
The utility model has the advantages that: a novel constraint structure is used, axial displacement can be compensated, and pressure thrust generated by the corrugated pipe is constrained. The novel constrained expansion joint capable of compensating the axial displacement can compensate the axial displacement and constrain pressure thrust, and has the characteristics of simple structure, safety and reliability.
Drawings
FIG. 1 is a schematic view of a hinge type expansion joint;
FIG. 2 is a schematic view of a tie-rod type expansion joint;
FIG. 3 is a schematic structural diagram of a straight pipe pressure balanced expansion joint of the external pressure type;
FIG. 4 is a schematic structural view of a straight pipe pressure balanced expansion joint of the internal pressure type;
fig. 5 is a schematic structural view of the present invention;
fig. 6 is a schematic view of the expansion joint axial compression displacement compensation mode of the present invention;
fig. 7 is a schematic view of the expansion joint axial tension displacement compensation mode of the present invention;
fig. 8 is another schematic structural diagram of the present invention;
in the figure: 1. the device comprises a first flange, 2, a constraint component, 3, a second flange, 4, a corrugated pipe, 5, a first end pipe, 6, a second end pipe, 2-1, a first piston, 2-2, a first compensation cavity, 2-3, a first displacement compensation sliding port, 2-4, a pull rod, 2-5, a second piston, 2-6, a second compensation cavity, 2-7, a second displacement compensation sliding port, 2-8 and a sealing ring.
Detailed Description
In order to make the technical solutions of the present invention better understood by those skilled in the art, the technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the examples of the present invention, and it is obvious that the described examples are only a part of examples of the present invention, and not all examples. Based on the examples in the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
In the description of the present embodiment, the terms "inside", "outside", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used merely to distinguish similar items and are not to be construed as requiring a particular order or sequence, and it is to be understood that such uses are interchangeable under appropriate circumstances.
As shown in figure 5, the restraint type corrugated pipe expansion joint capable of compensating axial displacement comprises a first flange 1, a corrugated pipe 4, a second flange 3 and a restraint member 2, wherein the two ends of the corrugated pipe 4 are respectively welded with the first flange 1 and the second flange 3, a plurality of groups of restraint members 2 are uniformly distributed on the outer side of the corrugated pipe 4 in the circumferential direction, a plurality of groups of first compensation cavities 2-2 with equal diameters are arranged on the first flange 1, one end of each first compensation cavity 2-2 is communicated with an inner cavity of the expansion joint, the other end of each first compensation cavity 2-2 is communicated with external air, a first displacement compensation sliding port 2-3 communicated with the first compensation cavity 2-2 is also arranged on the inner end surface of the first flange 1, the length of the first displacement compensation sliding port 2-3 meets the distance of compensating axial displacement, a plurality of groups of second compensation cavities 2-6 with equal diameters are arranged on the second flange 3, a second displacement compensation sliding port 2-7 communicated with the second compensation cavity 2-6 is also formed in the inner end surface (the surface close to the center of the expansion joint) of the second flange 3; the first compensation cavity 2-2 and the second compensation cavity 2-6 are arranged in a one-to-one correspondence mode, the first compensation cavity 2-2 and the second compensation cavity 2-6 are inclined towards the middle of the expansion joint, the inclination angles of the two cavities are the same, and a constraint component 2 is arranged between each group of the first compensation cavity 2-2 and the second compensation cavity 2-6 which are correspondingly arranged.
The constraint component 2 comprises a first piston 2-1, a second piston 2-5 and a pull rod 2-4, the first piston 2-1 is arranged in the first compensation cavity 2-2 in a sliding fit mode, the second piston 2-5 is arranged in the second compensation cavity 2-6 in a sliding fit mode, the pull rod 2-4 is arranged in an inclined mode, one end of the pull rod 2-4 penetrates through the first displacement compensation sliding port 2-3 and then is connected with the first piston 2-1, and the other end of the pull rod 2-4 penetrates through the second displacement compensation sliding port 2-7 and then is connected with the second piston 2-5.
The included angle of the first compensation cavity 2-2 and the first flange 1 plane, the included angle of the second compensation cavity 2-6 and the second flange 3 plane, the included angle of the pull rod 2-4 and the first flange 1 axis, and the included angle of the pull rod 2-4 and the second flange 3 axis are equal, so that the normal movement during displacement compensation is ensured.
The constraint principle is as follows: under the working state, flanges at two ends of the expansion joint are connected with a pipe system, the interior of the expansion joint is filled with a medium with the pressure p, and meanwhile, the medium enters the first compensation cavity 2-2 of the first flange 1. As shown in fig. 5. In order to realize pressure thrust constraint, a pressure constraint type bellows expansion joint structure must satisfy the following relational expression:
in the formula:
a is the cross-sectional area of the first piston 2-1;
Acthe effective area of the corrugated pipe (see GB/T12777-;
n is the total number of constraining members 2;
alpha is the plane included angle of the first compensation cavity 2-2 and the first flange 1, the plane included angle of the second compensation cavity 2-6 and the second flange 3, the axial line included angle of the pull rod 2-4 and the first flange 1, and the axial line included angle of the pull rod 2-4 and the second flange 3.
The pressure thrust acts on the first flange 1 and the second flange 3, the first flange 1 and the second flange 3 simultaneously receive the acting force of the restraining component 2, the resultant force of the acting force is equal to the pressure thrust in size and opposite to the pressure thrust in direction, and therefore the pressure thrust can be restrained. The pressure thrust is always constrained, whether the expansion joint is in the original position or in any axial deformation position.
The section of the first piston 2-1 is circular, and similarly, the first compensation cavity 2-2 is a cylindrical cavity.
The section of the second piston 2-5 is circular, and similarly, the second compensation cavity 2-6 is a cylindrical cavity.
A sealing ring 2-8 is sleeved on the first piston 2-1 in one side of the first compensation cavity 2-2 communicated with the inner cavity of the expansion joint. The first piston 2-1 is provided with a sealing ring groove for installing a sealing ring, and the installation direction of the sealing ring is close to the direction communicated with the inner cavity of the expansion joint.
As shown in fig. 8, the first flange 1 and the second flange 3 are respectively installed on the first end pipe 5 and the second end pipe 6 connected with the corrugated pipe, and other structures are the same as the structure of fig. 5, so that axial displacement compensation can be realized.
The displacement compensation mode is as follows:
(1) axial compressive displacement occurs: the pipeline is displaced, the first flange 1 and the second flange 3 are compressed to move towards the middle part of the expansion joint, in order to meet the deformation coordination condition, the first flange 1 and the second flange 3 push the first piston 2-1 and the second piston 2-5 to move along the same direction of the sealing cavity, and the pressure thrust is always born by the pull rod 2-4. A medium with pressure p is filled in a cavity formed by the pipeline, the first compensation cavity 2-2, the first piston 2-1 and the sealing ring 2-8; the cavity formed by the sealing cavity of the second flange 3 and the second piston 2-5 is air without pressure. According to the constraint principle, the pressure thrust in the moving process and at the displacement position is always kept in a constrained state. As shown in fig. 6.
(2) Axial tensile displacement occurs: the pipeline is displaced, the first flange 1 and the second flange 3 are stretched to move towards the middle of the expansion joint, in order to meet the deformation coordination condition, the first flange 1 and the second flange 3 push the first piston 2-1 and the second piston 2-5 to move along the sealing cavity in the same direction, and the pressure thrust is always borne by the pull rod. A medium with pressure p is filled in a cavity formed by the pipeline, the first compensation cavity 2-2, the first piston 2-1 and the sealing ring 2-8; the cavity formed by the sealing cavity of the second flange 3 and the second piston 2-5 is air without pressure. According to the constraint principle, the pressure thrust in the moving process and at the displacement position is always kept in a constrained state. As shown in fig. 7.